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Sample records for hybrid rice cultivar

  1. Performance of super hybrid rice cultivars grown under no-tillage and direct seeding

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    Min Huang

    2012-04-01

    Full Text Available Good progress has been made in the super hybrid rice (Oryza sativa L. breeding in China. However, rice yield not only depends on the genetic characteristics but also on the agronomic practices. No-tillage and direct seeding (NTDS is a simplified cultivation technology that greatly simplifies both land preparation and crop establishment. Aiming to determine the grain yield performance of super hybrid rice under NTDS and to identify critical factors that determine grain yield, field experiments were conducted in Nanxian, Hunan Province, China in 2009 and 2010. Two super hybrid cultivars, Liangyoupeijiu and Y-liangyou 1, were grown under conventional tillage and transplanting (CTTP and NTDS. Grain yield, yield components, biomass production, crop growth rate and biomass accumulation during sowing to heading (HD and HD to maturity were measured for each cultivar. There was no difference in grain yield under NTDS and CTTP. However, grain yield differed with cultivar and year. Y-liangyou 1 produced 4 % higher grain yield than Liangyoupeijiu in 2009, whereas in 2010 both cultivars yielded similarly. Grain yields of both cultivars were higher in 2009 than in 2010. Higher grain yield of Y-liangyou 1 in 2009 was associated with higher spikelet filling (spikelet filling percentage and grain weight, which resulted from higher biomass production. Crop growth rate after HD was critical for biomass production by the super hybrid rice. We suggest that increasing the crop growth rate after HD is an effective approach to increase grain yield of super hybrid rice under NTDS.

  2. Differential gene expression in an elite hybrid rice cultivar (Oryza sativa, L and its parental lines based on SAGE data

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    Chen Chen

    2007-09-01

    Full Text Available Abstract Background It was proposed that differentially-expressed genes, aside from genetic variations affecting protein processing and functioning, between hybrid and its parents provide essential candidates for studying heterosis or hybrid vigor. Based our serial analysis of gene expression (SAGE data from an elite Chinese super-hybrid rice (LYP9 and its parental cultivars (93-11 and PA64s in three major tissue types (leaves, roots and panicles at different developmental stages, we analyzed the transcriptome and looked for candidate genes related to rice heterosis. Results By using an improved strategy of tag-to-gene mapping and two recently annotated genome assemblies (93-11 and PA64s, we identified 10,268 additional high-quality tags, reaching a grand total of 20,595 together with our previous result. We further detected 8.5% and 5.9% physically-mapped genes that are differentially-expressed among the triad (in at least one of the three stages with P-values less than 0.05 and 0.01, respectively. These genes distributed in 12 major gene expression patterns; among them, 406 up-regulated and 469 down-regulated genes (P Conclusion We improved tag-to-gene mapping strategy by combining information from transcript sequences and rice genome annotation, and obtained a more comprehensive view on genes that related to rice heterosis. The candidates for heterosis-related genes among different genotypes provided new avenue for exploring the molecular mechanism underlying heterosis.

  3. Arsenic accumulation and phosphorus status in two rice (Oryza sativa L.) cultivars surveyed from fields in South China

    International Nuclear Information System (INIS)

    Lu Ying; Dong, Fei; Deacon, Claire; Chen Huojun; Raab, Andrea; Meharg, Andrew A.

    2010-01-01

    The consumption of paddy rice (Oryza sativa L.) is a major inorganic arsenic exposure pathway in S.E. Asia. A multi-location survey was undertaken in Guangdong Province, South China to assess arsenic accumulation and speciation in 2 rice cultivars, one an Indica and the other a hybrid Indica. The results showed that arsenic concentrations in rice tissue increased in the order grain < husk < straw < root. Rice grain arsenic content of 2 rice cultivars was significant different and correlated with phosphorus concentration and molar ratio of P/As in shoot, being higher for the Indica cultivar than for the hybrid Indica, which suggests altering shoot phosphorus status as a promising route for breeding rice cultivars with reduced grain arsenic. Speciation of grain arsenic, performed using HPLC-ICP-MS, identified inorganic arsenic as the dominant arsenic species present in the rice grain. - Altering rice shoot phosphorus status is a promising route for breeding rice cultivars with reduced grain arsenic.

  4. Cadmium accumulation in different rice cultivars and screening for pollution-safe cultivars of rice.

    Science.gov (United States)

    Yu, Hui; Wang, Junli; Fang, Wei; Yuan, Jiangang; Yang, Zhongyi

    2006-11-01

    Large areas of contaminated land are being used for agricultural production in some countries due to the high demand for food. To minimize the influx of pollutants to the human food chain through consumption of agricultural products, we propose the concept of pollution-safe cultivars (PSCs), i.e. cultivars whose edible parts accumulate a specific pollutant at a level low enough for safe consumption, even when grown in contaminated soil. We tested the feasibility of the PSC concept by growing 43 cultivars of paddy rice (Oryza sativa L., including 20 normal and 23 hybrid cultivars) under a high (75.69-77.55 mg kg(-1)) and a low (1.75-1.85 mg kg(-1)) cadmium (Cd) exposure. These pot experiments took place in the spring and summer of 2004. At the low level of Cd exposure, 30 out of the 43 tested cultivars were found to be Cd-PSCs. Grain Cd concentrations were highly correlated (price grain is genotype-dependent and that the selection of PSCs is possible, at least at a certain level of soil contamination. No Cd-PSCs were found under the high level of Cd exposure. Yield was enhanced in some cultivars and depressed in others in response to elevated soil Cd, indicating that farmers cannot rely on yield depression as an indicator of toxicity of the grains. It is therefore important and feasible to screen for PSCs and to establish PSC breeding programs to effectively and efficiently reduce the risk of human exposure to soil pollutants, such as Cd, through crop consumption.

  5. Intraspecific responses of 188 rice cultivars to enhanced UVB radiation

    International Nuclear Information System (INIS)

    Dai, Q.; Peng, A.; Chavez, A.Q.; Vergara, B.S.

    1994-01-01

    Phytotron studies were conducted to determine the intraspecific variation in sensitivity of rice (Oryza sativa L.) to enhanced UVB and to test the hypothesis that rice cultivars originating from regions with higher ambient UVB radiation are more tolerant to enhanced UVB. Out of the 188 rice cultivars (from various rice growing regions and ecosystems) tested, 143 had significantly reduced plant height, 52 had smaller leaf area, 61 had lower plant dry weight and 41 had less tiller number under elevated UVB radiation (13.0 kJ m −2 day −1 ) for 3 weeks. Six cultivars showed significant positive growth response to enhanced UVB radiation, although the mechanism is not clear at present. These six cultivars were from the summer rice crop of Bangladesh and from high elevation rice areas where prevailing UVB radiation is most likely to be greater. However, there was no correlation between the dry matter changes under enhanced UVB and the ambient UVB level at the origin of the cultivar across the 188 cultivars tested. Therefore, cultivars originating from regions with higher ambient UVB are not necessarily more tolerant to enhanced UVB radiation. (author)

  6. Low uptake affinity cultivars with biochar to tackle Cd-tainted rice — A field study over four rice seasons in Hunan, China

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    Chen, De; Guo, Hu; Li, Ruiyue [Institute of Resources, Ecosystem and Environment of Agriculture, and Center of Biochar and Green Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Li, Lianqing, E-mail: lqli@njau.edu.cn [Institute of Resources, Ecosystem and Environment of Agriculture, and Center of Biochar and Green Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Pan, Genxing [Institute of Resources, Ecosystem and Environment of Agriculture, and Center of Biochar and Green Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); Chang, Andrew [Department of Environmental Sciences, University of California, Riverside, CA 92521 (United States); Joseph, Stephen [Institute of Resources, Ecosystem and Environment of Agriculture, and Center of Biochar and Green Agriculture, Nanjing Agricultural University, 1 Weigang, Nanjing 210095 (China); School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)

    2016-01-15

    Biochar is becoming an environmentally friendly material for remediation of heavy metal contaminated soils and improving food safety. A field trial over four rice seasons was conducted to investigate the use of biochar and low Cd accumulating cultivars on Cd uptake in a heavy metal contaminated soil. Wheat straw derived biochar was applied at 0, 20 and 40 t ha{sup −1}. Two rice cultivars with differing Cd accumulation abilities were selected in each season. The results showed that both biochar and low Cd affinity cultivars significantly reduced rice grain Cd accumulation. Biochar had no significant effect the first season but thereafter consistently reduced rice grain Cd by a maximum of 61, 86 and 57% over the next three seasons. Zn accumulation in the rice grains was not decreased by biochar application, although available soil Zn was sharply reduced (35–91%). Indica conventional rice cultivars had much lower Cd, but higher Zn and lower Cd/Zn ratios in the grain than indica hybrid cultivars. Biochar was more effective for mitigating grain Cd accumulation in low Cd affinity cultivars than in high affinity cultivars. Soil pH was sustainably increased (up to nearly 1 unit) while available Cd significantly decreased by a maximum of 85% after biochar addition. The translocation of Cd from rice roots to shoots was reduced from 20 to 80% by biochar. Low uptake affinity cultivars combined with biochar reduced late rice grain Cd concentration and Cd/Zn ratios by 69–80% and 72–80%, respectively. It indicated that the management of combining biochar and low Cd affinity cultivars should be an efficient way to remediate Cd contaminated rice paddies and reduce health risk associated with consuming rice from these soils. - Highlights: • Biochar sustainably reduced soil Cd availability and Cd translocation in rice plant. • Indica conventional cultivars had lower Cd but higher Zn in grains than hybrid ones. • Biochar significantly reduced grain Cd and Cd/Zn ratio

  7. Low uptake affinity cultivars with biochar to tackle Cd-tainted rice — A field study over four rice seasons in Hunan, China

    International Nuclear Information System (INIS)

    Chen, De; Guo, Hu; Li, Ruiyue; Li, Lianqing; Pan, Genxing; Chang, Andrew; Joseph, Stephen

    2016-01-01

    Biochar is becoming an environmentally friendly material for remediation of heavy metal contaminated soils and improving food safety. A field trial over four rice seasons was conducted to investigate the use of biochar and low Cd accumulating cultivars on Cd uptake in a heavy metal contaminated soil. Wheat straw derived biochar was applied at 0, 20 and 40 t ha"−"1. Two rice cultivars with differing Cd accumulation abilities were selected in each season. The results showed that both biochar and low Cd affinity cultivars significantly reduced rice grain Cd accumulation. Biochar had no significant effect the first season but thereafter consistently reduced rice grain Cd by a maximum of 61, 86 and 57% over the next three seasons. Zn accumulation in the rice grains was not decreased by biochar application, although available soil Zn was sharply reduced (35–91%). Indica conventional rice cultivars had much lower Cd, but higher Zn and lower Cd/Zn ratios in the grain than indica hybrid cultivars. Biochar was more effective for mitigating grain Cd accumulation in low Cd affinity cultivars than in high affinity cultivars. Soil pH was sustainably increased (up to nearly 1 unit) while available Cd significantly decreased by a maximum of 85% after biochar addition. The translocation of Cd from rice roots to shoots was reduced from 20 to 80% by biochar. Low uptake affinity cultivars combined with biochar reduced late rice grain Cd concentration and Cd/Zn ratios by 69–80% and 72–80%, respectively. It indicated that the management of combining biochar and low Cd affinity cultivars should be an efficient way to remediate Cd contaminated rice paddies and reduce health risk associated with consuming rice from these soils. - Highlights: • Biochar sustainably reduced soil Cd availability and Cd translocation in rice plant. • Indica conventional cultivars had lower Cd but higher Zn in grains than hybrid ones. • Biochar significantly reduced grain Cd and Cd/Zn ratio, though

  8. An Economic Risk Analysis of Weed Suppressive Rice Cultivars in Rice Production

    Science.gov (United States)

    Weeds are a major constraint to rice production. In the United States, most rice cultivars are not inherently weed-suppressive and require substantial herbicide inputs to achieve agronomic and economic viability. Intensive herbicide application in rice also has many potential drawbacks, resulting in...

  9. Improvement of west Sumatra black rice cultivar through mutation induction

    International Nuclear Information System (INIS)

    Benny Warman; Sobrizal; Irfan Suliansyah; Etti Swasti; Auzar Syarif

    2015-01-01

    Black rice cultivar is a local rice cultivar originating from East Pasaman, West Sumatera which has black endosperm, long growth duration and high plant height. The research was conducted from March 2012 until March 2013 with the objective of improvement the genetic of this black rice cultivar, especially related to the growth duration through mutation breeding. To get the optimum dose, the seeds of this cultivar were irradiated by gamma ray with doses of 0, 100, 200, 300, 400 and 500 Gy, respectively at Center of the Application of Isotopes and Radiation, National Nuclear Energy Agency (PAIR - BATAN), Jakarta. Base don the data of percentage of germination, plant height and root length in the seedling stage, and the percentage of grain sterility in M1 plants, it was obtained that the dose of 200-300 Gy is an effective dose in generating genetic diversity. It was agree with result of variability observations in M2 population derived from 200 Gy irradiated seeds, in which the extensive genetic diversities were observed in the variable of plant height, number of productive tillers and growth duration. From the selection in M2 population it was obtained 81 early maturing plants, with mutant frequency of 0.08 %. These selected early maturing mutants are very useful as initial plant materials in developing black rice leading mutant variety(s) in the future. (author)

  10. Genetic diversity analysis of rice cultivars from various origins using ...

    African Journals Online (AJOL)

    Genetic diversity is of paramount importance for the success of any plant breeding program. An experiment was conducted to assess the extent of genetic diversity and similarity of 24 rice cultivars from various origins using 29 simple sequence repeat (SSR) markers. A total of 144 alleles were detected at the 29 SSR primer ...

  11. Kinetic parameters of silicon uptake by rice cultivars

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    Priscila Oliveira Martins

    2012-02-01

    Full Text Available Silicon is considered an important chemical element for rice, because it can improve tolerance to biotic and abiotic stress. However, in many situations no positive effect of silicon was observed, probably due to genetic factors. The objective of this research was to monitor Si uptake kinetics and identify responses of rice cultivars in terms of Si uptake capacity and use. The experiment was carried out in a greenhouse of the São Paulo State University (UNESP, Brazil. The experiment was arranged in a completely randomized, factorial design with three replications. that consisted of two rice cultivars and two Si levels. Kinetic parameters (Vmax, Km, and Cmin, root morphology variables, dry matter yield, Si accumulation and levels in shoots and roots, uptake efficiency, utilization efficiency, and root/shoot ratio were evaluated. Higher Si concentrations in the nutrient solution did not increase rice dry matter. The development of the low-affinity silicon uptake system of the rice cultivar 'Caiapó' was better than of 'Maravilha'.

  12. Detection of DNA fingerprints of cultivated rice by hybridization with a human minisatellite DNA probe

    International Nuclear Information System (INIS)

    Dallas, J.F.

    1988-01-01

    A human minisatellite DNA probe detects several restriction fragment length polymorphisms in cultivars of Asian and African rice. Certain fragments appear to be inherited in a Mendelian fashion and may represent unlinked loci. The hybridization patterns appear to be cultivar-specific and largely unchanged after the regeneration of plants from tissue culture. The results suggest that these regions of the rice genome may be used to generate cultivar-specific DNA fingerprints. The demonstration of similarity between a human minisatellite sequence and polymorphic regions in the rice genome suggests that such regions also occur in the genomes of many other plant species

  13. Evaluation of antioxidant potential of Brazilian rice cultivars

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    Sylvio Vicentin Palombini

    2013-12-01

    Full Text Available This study quantified the fatty acids and evaluated the proximate composition, antioxidant activity (using the Quencher procedure, and total phenolic compound concentrations in Brazilian rice cultivars. The cultivars studied showed high amounts of unsaturated fatty acids, such as linoleic and oleic acid. The ratios of polyunsaturated and saturated fatty acids obtained were high. Regarding the antioxidant activity, the best results were found using the ABTS method and the worst in the DPPH assay. The results of the DPPH and FRAP assays showed the highest correlation. The antioxidant capacity results obtained were also much higher than those reported for other varieties worldwide. Therefore, the Quencher procedure is highly suitable for application in cereals such as rice, especially when combined with the ABTS radical capture method.

  14. The contrasting responses of soil microorganisms in two rice cultivars to elevated ground-level ozone

    International Nuclear Information System (INIS)

    Feng, Youzhi; Yu, Yongjie; Tang, Haoye; Zu, Qianhui; Zhu, Jianguo; Lin, Xiangui

    2015-01-01

    Although elevated ground-level O 3 has a species–specific impact on plant growth, the differences in soil biota responses to O 3 pollution among rice cultivars are rarely reported. Using O 3 Free-Air Concentration Enrichment, the responses of the rhizospheric bacterial communities in the O 3 -tolerant (YD6) and the O 3 -sensitive (IIY084) rice cultivars to O 3 pollution and their differences were assessed by pyrosequencing at rice tillering and anthesis stages. Elevated ground-level O 3 negatively influenced the bacterial community in cultivar YD6 at both rice growth stages by decreasing the bacterial phylogenetic diversities and response ratios. In contrast, in cultivar IIY084, the bacterial community responded positively at the rice tillering stage under O 3 pollution. However, several keystone bacterial guilds were consistently negatively affected by O 3 pollution in two rice cultivars. These findings indicate that continuously O 3 pollution would negatively influence rice agroecosystem and the crop cultivar is important in determining the soil biota responses to elevated O 3 . - Highlights: • We investigated the soil biota in two rice cultivars in presence of elevated O 3 . • The contrasting responses of soil biota were found between two rice cultivars. • Some keystone bacterial guilds were consistently negatively affected by O 3 pollution. • The crop cultivar is important in determining soil biota responses to elevated O 3 . - The crop cultivar is important in determining the soil biota responses to elevated O 3

  15. Leaf gas exchange and yield of three upland rice cultivars

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    Rita de Cássia Félix Alvarez

    2015-03-01

    Full Text Available Studies of physiological parameters associated with crop performance and growth in different groups of upland rice (Oryza sativa L. may support plant breeding programs. We evaluated the role of gas exchange rates and dry matter accumulation (DMA as traits responsible for yields in a traditional (cv. ‘Caiapó’, intermediate (cv. ‘Primavera’ and modern (cv. ‘Maravilha’ upland rice cultivars. Leaf gas exchange rates, DMA, leaf area index (LAI, harvest indexes (HI and yield components were measured on these genotypes in the field, under sprinkler irrigation. Panicles per m2 and DMA at flowering (FL and heading, as well as CO2 assimilation rates (A were similar across these cultivars. The highest yield was found in ‘Primavera’, which may be explained by (i a two-fold higher HI compared to the other cultivars, (ii greater rates of DMA during spikelet formation and grain-filling, as well as (iii a slow natural decrease of A in this cultivar, at the end of the season (between FL and maturation.

  16. Mechanisms of UVB-resistance in rice: Cultivar differences in the sensitivity to UVB radiation in rice

    International Nuclear Information System (INIS)

    Hidema, J.

    2001-01-01

    In a study on the sensitivity to UVB radiation of rice cultivars of 5 Asian rice ecotypes, results showed that the rice cultivars widely varied in UVB sensitivity; among the Japanese rice cultivars, Sasanishiki was more resistant to UVB, while Norin 1 was less resistant; UV-sensitive Norin 1 was deficient in photorepair of cyclobutane pyrimidine dimers (UV-induced DNA damage), and the sensitivity to UVB radiation significantly correlated with deficient CPD photorepair; and that this deficiency in Norin 1 resulted from a functionally altered photolyase. The results suggest that photorepair capacity is a principal factor in determining UVB sensitivity in rice. The effects of supplemental UVB radiation on the growth and yield of Japanese rice cultivars under field conditions were also studied in Japan since 1993. The results indicate that supplemental UVB radiation had inhibitory effects on the growth and yield of rice. Furthermore, grain size was smaller with supplemental UVB radiation

  17. Genome-wide indel markers shared by diverse Asian rice cultivars compared to Japanese rice cultivar ?Koshihikari?

    OpenAIRE

    Yonemaru, Jun-ichi; Choi, Sun Hee; Sakai, Hiroaki; Ando, Tsuyu; Shomura, Ayahiko; Yano, Masahiro; Wu, Jianzhong; Fukuoka, Shuichi

    2015-01-01

    Insertion-deletion (indel) polymorphisms, such as simple sequence repeats, have been widely used as DNA markers to identify QTLs and genes and to facilitate rice breeding. Recently, next-generation sequencing has produced deep sequences that allow genome-wide detection of indels. These polymorphisms can potentially be used to develop high-accuracy polymerase chain reaction (PCR)-based markers. Here, re-sequencing of 5 indica, 2 aus, and 3 tropical japonica cultivars and Japanese elite cultiva...

  18. THE EFFECT OF RICE CULTIVARS ON METHANE EMISSION FROM IRRIGATED RICE FIELD

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    P. Setyanto

    2016-10-01

    Full Text Available Rice plants have been reported to affect methane (CH4 emission from rice fields. The objectives of this study were to determine the effect of rice cultivars on CH4 emission from flooded rice and to develop crop management strategies with low emitting rice cultivars while sustaining high yield. The four rice cultivars studied were Memberamo, Cisadane, IR64, and Way Apoburu. The CH4 emissions were determined in the wet season of 2001/2002 (November-February using an automated closed chamber technique in an irrigated field condition. Farmyard manure at the rate of 5 t ha-1 was given to the plots to ensure carbon was not limited. Root weight, root length, biomass, and number of tillers were determined at 17, 36, and 57 days after transplanting (DAT. The results showed that the mean CH4 emission was highest in the plot planted with Cisadane (94.8 kg CH4 ha-1, and the lowest with IR64 (37.7 kg CH4 ha-1. The plots treated with emberamo and Way Apoburu resulted an intermediate CH4 emission at the average of 61.1 and 58.9 kg CH4 ha-1, respectively. There was no significant difference in yield between the cultivars tested. The yield of Memberamo, Cisadane, IR64, and Way Apoburu were 5.882, 5.764, 5.873 and 6.065 t ha-1, respectively. Statistical analysis showed that there were no significant differences in the root weight and root length among cultivars. However, Cisadane gave the highest dry matter weight (222 g hill-1 at 57 DAT compared to the other cultivars (175-190 g hill-1. Plant tillers did not show significant differences between the cultivars. Regression analysis showed that CH4 flux was significantly related with root weight, root length, aboveground biomass, and number of plant tillers. This finding shows that the use of selected cultivars, such as IR64, can potentially lower CH4 emission without scarifying yield.

  19. Harvest season and head rice yield of upland rice cultivars submitted to parboiling

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    Diva Mendonça Garcia

    2012-11-01

    Full Text Available Normal 0 21 false false false PT-BR X-NONE X-NONE This work aimed to evaluate the effects of parboiling on the yield of upland rice cultivars harvested at different times. The cultivars were BRS Primavera and BRS Sertaneja, harvested at 30 and 47 days after flowering (DAF. For parboiling, samples were soaked in water bath at 65 °C in grain: water ratio of 1:1.6 in order to reach 25% and 30% moisture, and then were autoclaved for 10 minutes at 120 °C and 1.1 kg/cm2 of pressure. After drying up to 13% moisture in a greenhouse with forced air at 40 °C, samples were benefited, followed by separation using the trieur equipment and weighing to obtain the head rice yield. The results showed a higher yield for head rice harvested at 30 DAF than at 47 DAF (BRS Primavera 63.2 and 38.7%; BRS Sertaneja 68.5 and 55.7%, respectively. Parboiling increased the head rice yield, regardless of harvest season, but partly reflected the potential of the cultivar origin: BRS Primavera 70.06%, BRS Sertaneja 74.94%. It is concluded that the harvest season is one of the factors that most influence the quality of industrial rice and the effect of parboiling also depends on the potential of the material source.

  20. Genetic diversity of high performance cultivars of upland and irrigated Brazilian rice.

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    Coelho, G R C; Brondani, C; Hoffmann, L V; Valdisser, P A M R; Borba, T C O; Mendonça, J A; Rodrigues, L A; de Menezes, I P P

    2017-09-21

    The objective of this study was to analyze the diversity and discrimination of high-performance Brazilian rice cultivars using microsatellite markers. Twenty-nine rice cultivars belonging to EMBRAPA Arroz e Feijão germplasm bank in Brazil were genotyped by 24 SSR markers to establish their structure and genetic discrimination. It was demonstrated that the analyzed germplasm of rice presents an expressive and significant genetic diversity with low heterogeneity among the cultivars. All 29 cultivars were differentiated genetically, and were organized into two groups related to their upland and irrigated cultivation systems. These groups showed a high genetic differentiation, with greater diversity within the group that includes the cultivars for irrigated system. The genotyping data of these cultivars, with the morphological e phenotypical data, are valuable information to be used by rice breeding programs to develop new improved cultivars.

  1. Alterations in growth, oxidative damage, and metal uptake of five aromatic rice cultivars under lead toxicity.

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    Ashraf, Umair; Hussain, Saddam; Anjum, Shakeel Ahmad; Abbas, Farhat; Tanveer, Mohsin; Noor, Mehmood Ali; Tang, Xiangru

    2017-06-01

    Lead (Pb) affects plant growth and its related physio-biochemical functions negatively. The present study investigated the responses of five different fragrant rice cultivars viz., Meixiangzhan (MXZ-2), Xiangyaxiangzhan (XYXZ), Guixiangzhan (GXZ), Basmati-385 (B-385), and Nongxiang-18 (NX-18) to four different Pb concentrations viz., 0, 400, 800 and 1200 μM. Results depicted that Pb toxicity significantly (P rice plants; nonetheless, a significant variation was found in the sensitivity of rice cultivars to Pb toxicity. Soluble sugars increased significantly only at 1200 μM in GXZ and 800 μM in B-385, whilst the maximum reductions in protein contents were observed at 1200 μM Pb for all rice cultivars. Proline contents were reduced for XYXZ and NX-18 at Pb1200 μM. Activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) as well as reduced glutathione (GSH) and oxidized glutathione (GSSG) showed differential behavior among Pb treatments and rice cultivars. Among rice cultivars, GXZ showed better antioxidative defense system under Pb toxicity compared with all other cultivars. For all rice cultivars, the trend for Pb accumulation was recorded as: roots > stems > leaves. Furthermore, significant but negative correlations among Pb uptake and plant height (r = -0.79), tillers per plant (r = -0.91) and plant dry biomass (r = -0.81) were recorded for all rice cultivars whereas the values of translocation factor (TF) from stems to leaves were higher than roots to stems. In sum, Pb reduced the early growth and caused physio-biochemical changes in all rice cultivars, nonetheless, GXZ proved better able to tolerate Pb stress than all other rice cultivars under study. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. New hybrid rice cultivar 'Zhefuliangyou 12' with improved grain quality produced by leaf color marker-labeled male sterile line and mutant with enhanced tillers and improved grain quality

    International Nuclear Information System (INIS)

    Mei Shufang; Zhao Hua; Wang Yongqiang; Shu Xiaoli; Wu Dianxing

    2013-01-01

    In order to breed high yielding and good grain quality new variety with controllable seed purity, hybrid rice 'Zhefuliangyou 12' was produced by green-revertible albino leaf color marker-labeled two-line male sterile line 'NHR111S' and mutant 'ZF-2' with enhanced tillers and improved grain quality, which was characterized by improved grain quality, rice blast resistance and lodging resistance. Breeding protocol, characteristics, and high yielding cultivation techniques of 'Zhefuliangyou 12' were briefly introduced in the current paper. (authors)

  3. Genotypic differences among rice cultivars in lead accumulation and translocation and the relation with grain Pb levels.

    Science.gov (United States)

    Liu, Jianguo; Ma, Xinmei; Wang, Mingxin; Sun, Xiangwu

    2013-04-01

    In order to understand the differences among rice cultivars and genotypes in lead (Pb) uptake and translocation, and their relationship with Pb accumulation in rice grains, pot soil experiments were carried out with six rice cultivars of diverse types under different soil Pb levels. The results showed that the differences among rice cultivars in Pb concentrations varied largely with plant organs, and the magnitudes of the differences were larger in ears and grains than in shoots and roots. Pb concentrations in ears and grains differed significantly (price types, and were in the order: Hybrid Indica>Indica>Japonica. Grain Pb concentrations were correlated significantly (price cultivars in translocation factors (TF) of Pb from shoots to ears/grains were generally larger than the TF of Pb from roots to shoots. The differences among rice types in TF of Pb from shoots to ears/grains were generally significant (pIndica>Japonica. But the differences between rice types in the TF of Pb from roots to shoots were mostly insignificant (p>0.05). In general, grain Pb concentrations were correlated significantly (p0.05) with the TF of Pb from roots to shoots. So the Pb in shoots, but not in roots, may be the main sources of Pb transferred to the grains. Pb concentrations in rice grains are likely to be determined mainly by the translocations of Pb from shoots to the grains, and little by the transport from roots to shoots. Pb concentration in ears of heading can be used as an index of Pb level in the grains. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Cropping system diversification for food production in Mindanao rubber plantations: a rice cultivar mixture and rice intercropped with mungbean

    Science.gov (United States)

    Elazegui, Francisco; Duque, Jo-Anne Lynne Joy E.; Mundt, Christopher C.; Vera Cruz, Casiana M.

    2017-01-01

    Including food production in non-food systems, such as rubber plantations and biofuel or bioenergy crops, may contribute to household food security. We evaluated the potential for planting rice, mungbean, rice cultivar mixtures, and rice intercropped with mungbean in young rubber plantations in experiments in the Arakan Valley of Mindanao in the Philippines. Rice mixtures consisted of two- or three-row strips of cultivar Dinorado, a cultivar with higher value but lower yield, and high-yielding cultivar UPL Ri-5. Rice and mungbean intercropping treatments consisted of different combinations of two- or three-row strips of rice and mungbean. We used generalized linear mixed models to evaluate the yield of each crop alone and in the mixture or intercropping treatments. We also evaluated a land equivalent ratio for yield, along with weed biomass (where Ageratum conyzoides was particularly abundant), the severity of disease caused by Magnaporthe oryzae and Cochliobolus miyabeanus, and rice bug (Leptocorisa acuta) abundance. We analyzed the yield ranking of each cropping system across site-year combinations to determine mean relative performance and yield stability. When weighted by their relative economic value, UPL Ri-5 had the highest mean performance, but with decreasing performance in low-yielding environments. A rice and mungbean intercropping system had the second highest performance, tied with high-value Dinorado but without decreasing relative performance in low-yielding environments. Rice and mungbean intercropped with rubber have been adopted by farmers in the Arakan Valley. PMID:28194318

  5. The Role of Node Restriction on Cadmium Accumulation in the Brown Rice of 12 Chinese Rice (Oryza sativa L.) Cultivars.

    Science.gov (United States)

    Huang, Gaoxiang; Ding, Changfeng; Guo, Fuyu; Li, Xiaogang; Zhou, Zhigao; Zhang, Taolin; Wang, Xingxiang

    2017-11-29

    For selection or breeding of rice (Oryza sativa L.) cultivars with low Cd affinity, the role of node Cd restriction on Cd accumulation in brown rice was studied. A pot experiment was conducted to investigate the concentration of Cd in different sections of 12 Chinese rice cultivars. The results indicated that the Cd accumulation in the brown rice was mainly dependent on the root or shoot Cd concentration. Among the cultivars with nearly equal shoot Cd concentrations, Cd accumulation in brown rice was mainly dependent on the transport of Cd in the shoot. However, the Cd transport in the shoot was significantly restricted by the nodes, especially by the first node. Furthermore, the area of the diffuse vascular bundle in the junctional region of the flag leaf and the first node was a key contributor to the variations in Cd restriction by the nodes.

  6. Effects of Salt Stress on Germination and Early Seedling Growth of Some Kenyan Rice Cultivars

    International Nuclear Information System (INIS)

    Ochieng, C.A.; Onkware, A.O.

    1999-01-01

    Four rice cultivars (Basmati-217, BW-196, Sindano and Ita-310) were subjected to increasing substrate salinity (0-1.5 Sm -1 ECe), under both laboratory and soil experiments. The salt stress significantly (P -1 ECe) completely inhibited germination in potted soil, but not petri dish tests in the laboratory.It was concluded that the three rice cultivars are susceptible to even mild substrate salinity, and cannot be relied upon for cultivation in saline soils. There is a need to assess the response many of the rice cvv for resistance to salt stress, and, if possible isolate and develop high yielding, resistant cultivars

  7. Plant type improvement of indigenous rice cultivars through induced mutations

    International Nuclear Information System (INIS)

    Kihupi, A.

    1997-01-01

    A high yielding, locally adapted cultivar 'Afaa Mwanza 1/159' of rice (Oryza sativa L.) which is tall and late in maturity, was irradiated with gamma rays at doses of 170, 210 and 250 Gy to shorten plant height and time of maturity. Twelve mutants were selected, and evaluated for yield performance in field trials from M 6 to M 9 generations. All the mutants were shorter in plant height, and gave higher mean yield than the parent. Correlation coefficient analysis showed that the number of productive tillers, number of panicles per square meter and grain filling in the panicle were important characters which influenced yield. On the other hand, panicle length had negative influence on yield. Cv. 'Supa India' and 'Salama' were also irradiated with doses of 170, 210, 240 Gy gamma rays. Analysis of M 2 populations of these cultivars indicated that mutagenesis created a lot of variation in plant height, maturity, spikelet fertility and panicle length. The induced variation shall be useful in selecting desired plant types. (author). 16 refs, 12 tabs

  8. Plant type improvement of indigenous rice cultivars through induced mutations

    Energy Technology Data Exchange (ETDEWEB)

    Kihupi, A [Department of Crop Science and Production, Sokoine Univ. of Agriculture, Morogoro (Tanzania)

    1997-07-01

    A high yielding, locally adapted cultivar `Afaa Mwanza 1/159` of rice (Oryza sativa L.) which is tall and late in maturity, was irradiated with gamma rays at doses of 170, 210 and 250 Gy to shorten plant height and time of maturity. Twelve mutants were selected, and evaluated for yield performance in field trials from M{sub 6} to M{sub 9} generations. All the mutants were shorter in plant height, and gave higher mean yield than the parent. Correlation coefficient analysis showed that the number of productive tillers, number of panicles per square meter and grain filling in the panicle were important characters which influenced yield. On the other hand, panicle length had negative influence on yield. Cv. `Supa India` and `Salama` were also irradiated with doses of 170, 210, 240 Gy gamma rays. Analysis of M{sub 2} populations of these cultivars indicated that mutagenesis created a lot of variation in plant height, maturity, spikelet fertility and panicle length. The induced variation shall be useful in selecting desired plant types. (author). 16 refs, 12 tabs.

  9. In-vitro culture performance of rice cultivars

    International Nuclear Information System (INIS)

    Oard, J.H.; Rutger, J.N.

    1989-01-01

    Full text: Four California rice varieties (L-202, S-201, M-202 and Calmochi 101) and one Texas rice (Lemont) were tested for embryogenic calli produced from mature seeds. Of these varieties S-201, M-202 and Calmochi 101 derived from mutant crosses as follows (mutant parent underlined). S-201 (Calrose 76 x Cs-M3) x S6; M-202 (IR8 x Cs-M3) x (10-7 x M-101); Calmochi 101 Tatsumi mochi x (M7 x S6). S-201 was the only cultivar that produced many shoots from virtually all portions of the embryogenic callus. M-202 produced the highest no. of shoots at the upper level of hormone (BAP). Regeneration of Calmochi 101 was rather poor. The frequency of albino shoots was also different for the varieties tested: 0.027 for L-202; 0.00 for Calmochi 101; 0.016 for S-201; 0.045 for Lemont; 0.037 for M-202. Albino shoots were found only with 0.1 mg 1 -1 BAP in the regeneration medium, except for Lemont which produced albinos without cytokinin. (author)

  10. Incorporation of Bacterial Blight Resistance Genes Into Lowland Rice Cultivar Through Marker-Assisted Backcross Breeding.

    Science.gov (United States)

    Pradhan, Sharat Kumar; Nayak, Deepak Kumar; Pandit, Elssa; Behera, Lambodar; Anandan, Annamalai; Mukherjee, Arup Kumar; Lenka, Srikanta; Barik, Durga Prasad

    2016-07-01

    Bacterial blight (BB) of rice caused by Xanthomonas oryzae pv. oryzae is a major disease of rice in many rice growing countries. Pyramided lines carrying two BB resistance gene combinations (Xa21+xa13 and Xa21+xa5) were developed in a lowland cultivar Jalmagna background through backcross breeding by integrating molecular markers. In each backcross generation, markers closely linked to the disease resistance genes were used to select plants possessing the target genes. Background selection was continued in those plants carrying resistant genes until BC(3) generation. Plants having the maximum contribution from the recurrent parent genome were selected in each generation and hybridized with the recipient parent. The BB-pyramided line having the maximum recipient parent genome recovery of 95% was selected among BC3F1 plants and selfed to isolate homozygous BC(3)F(2) plants with different combinations of BB resistance genes. Twenty pyramided lines with two resistance gene combinations exhibited high levels of tolerance against the BB pathogen. In order to confirm the resistance, the pyramided lines were inoculated with different X. oryzae pv. oryzae strains of Odisha for bioassay. The genotypes with combination of two BB resistance genes conferred high levels of resistance to the predominant X. oryzae pv. oryzae isolates prevalent in the region. The pyramided lines showed similarity with the recipient parent with respect to major agro-morphologic traits.

  11. Variation in Yield and Physicochemical Quality Traits among Mutants of Japonica Rice Cultivar Wuyujing 3

    OpenAIRE

    Abacar, Jose Daniel; Zhao-miao, Lin; Xin-cheng, Zhang; Cheng-qiang, Ding; She, Tang; Zheng-hui, Liu; Shao-hua, Wang; Yan-feng, Ding

    2016-01-01

    To select elite germplasms, 112 mutants derived from japonica rice cultivar Wuyujing 3 were evaluated. The yield components such as panicle number per square meter, grain number per panicle, and grain weight were measured. The quality traits such as percentage of chalky grains (PCG), brown rice yield (BRY), milled rice yield (MRY), degree of milling (DM), amylose content (AC), protein content (PC), and relationships among traits were inverstigated. Results showed that grain yield ranged from ...

  12. [Introduction of upland rice cultivars to eastern Keerqin sandy land and their biological characteristics].

    Science.gov (United States)

    Zeng, Dehui; Zhang, Chunxing; Wang, Guirong; Fan, Zhiping

    2004-10-01

    Developing water-saving rice cultivation is one important strategy for food security in China. This paper reported the experimental results of introducing six upland rice cultivars to eastern Keerqin sandy land. The field experiment results showed that under the condition of 60% water-saving, the yield of cultivars XH 95-13 and XH 95-13-6 was 10.2% and 5.5% higher than the control, respectively, while other four cultivars decreased by 6.7%-18.6%. Economically, all the cultivars except JP 121 had a higher income than the control, and the profitability of cultivars XH 95-13 and XH 95-13-6 reached 24.0% and 19.3%, respectively. The water productivity of all the six cultivars was over 0.566 kg x m(-3), increased by 59.89%-116.38%. Pot experiment showed that 12.1%-16.3% of soil moisture in 0-15 cm layer was beneficial to the growth of upland rice. In eastern Keerqin sandy land, effective tillers occurred before July 18. In brief, upland rice production could be extensively applicable in eastern Keerqin sandy land to gradually alternate the traditional lowland rice cultivation with continuous flooding, and save much underground water.

  13. Iron plaque formation on roots of different rice cultivars and the relation with lead uptake.

    Science.gov (United States)

    Liu, Jianguo; Leng, Xuemei; Wang, Mingxin; Zhu, Zhongquan; Dai, Qinghua

    2011-07-01

    The relationships between lead (Pb) uptake and iron/manganese plaque formation on rice roots were investigated with three cultivars. The results showed that the rice cultivars with indica consanguinity were more sensitive to soil Pb stress than the cultivar with japonica consanguinity. Pb concentrations and distribution ratios in root tissues were in the order: Shanyou 63 > Yangdao 6 > Wuyunjing 7, but Pb and Fe concentrations and distribution ratios in the plaques showed a reverse order. Mn concentrations and distribution ratios in the plaques of Wuyunjing 7 were significantly higher (P rice root can provide a barrier to soil Pb stress. The plaque will increase sequestration of Pb on rice root surface and in the rhizosphere, providing a means of external exclusion of soil Pb to some extent. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Elemental Composition of Two Rice Cultivars under Potentially Toxic an Aquept and Aquent

    Directory of Open Access Journals (Sweden)

    Adesola Olutayo OLALEYE

    2009-12-01

    Full Text Available Iron toxicity is a major nutrient disorder affecting rice production of wetland rice in the irrigated and rainfed ecosystem in West Africa sub-region. Little attention has been paid to evaluating nutrient contents of rice cultivars grown on such soils and their relationship to the iron toxicity scores, grain yield and dry matter yields. A pot experiment was conducted on two potentially Fe-toxic soils (Aeric Fluvaquent and Aeric Tropaquept. The experiment was a 2 x 2 x 4 factorial experiment with three replicates in arranged in a randomized fashion. The factors were two soil types, two rice cultivars (ITA 212 and tolerant (Suakoko 8 and four Fe 2+ levels (control, 1000, 3000 and 4000 mg L-1. The result showed that for both susceptible cultivar (ITA 212 and the relatively tolerant (Suakoko 8 cultivar, little or no differences were observed in their elemental composition with regards to micro and macro-nutrients. For the susceptible cultivar, results showed that none of the tissue nutrients significantly relates to iron toxicity scores (ITS, grain yield and dry matter yield on both soil types. However, for the tolerant cultivar, ITS was observed to be significantly related to tissue K and P contents on the two soil types respectively. Tissue Ca and Mg were observed to be significantly related to the dry matter yield (DMY on Aeric Tropquept. It could be concluded that for these rice cultivars grown on two potentially Fe-toxic soils, different tissue nutrients may trigger the manifestation of bronzing or yellowing symptoms of rice cultivars.

  15. PERFORMANCE OF PROMISING HYBRID RICE IN TWO DIFFERENT ELEVATIONS OF IRRIGATED LOWLAND IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Yuni Widyastuti

    2015-06-01

    Full Text Available The hybrid rice program has been established since early 1990’s at the Indonesia Center for Rice Research (ICRR. Twenty-four experimental hybrid rice varieties which have been developed were tested in lowland rice fields in Sukamandi (West Java and Batang (Central Java during the dry season and the rainy season of 2012. Randomized complete block design (RCBD with three replications was used in each location. The results showed that grains yields were affected by locations, seasons, and genotypes. The genotypes x locations x seasons interaction effect was significant; therefore, the best hybrid was different for each location and season. A7/PK36 hybrid has the best performance in Batang during the dry season, while A7/PK40 and A7/PK32 are the best hybrids in the rainy season. In Sukamandi, nine hybrids were identified as better yielder than that of the check cultivar in the dry season, but not so in the rainy season. Using the correlation and path analysis, we found that the number of panicles per hill and the number of filled grains per panicle could be used as selection criteria for yield in hybrid rice.

  16. Uptake and translocation of Cd in different rice cultivars and the relation with Cd accumulation in rice grain

    International Nuclear Information System (INIS)

    Liu Jianguo; Qian Min; Cai Guoliang; Yang Jianchang; Zhu Qingsen

    2007-01-01

    The variations among six rice cultivars in cadmium (Cd) uptake and translocation were investigated with pot soil experiments. The results showed that only a very small portion (0.73%) of Cd absorbed by rice plant was transferred into grain. With regard to plant total Cd uptake, Cd concentrations and quantity accumulations in roots, stems and leaves, the differences among the cultivars (between the largest one and the smallest one) were less than one time. But for Cd concentrations and Cd quantity accumulations in the grains, the differences were more than five and eight times, respectively. With respect to Cd distribution portions in plant organs, the diversities among the cultivars were also small in roots, stems and leaves, but much larger in grains. Grain Cd concentrations correlated positively and significantly (P < 0.01) with Cd quantity accumulations in plant, Cd distribution ratios to aboveground parts, and especially with Cd distribution ratios from aboveground parts to the grain. The results indicated that Cd concentration in rice grain was governed somewhat by plant Cd uptake and the transport of Cd from root to shoot, and in a greater extent, by the transport of Cd from shoot to grain. Cd was not distributed evenly in different products after rice grain processing. The average Cd concentration in cortex (embryo) was five times more than that in chaff and polished rice. With regard to Cd quantity accumulation in the products, near 40% in cortex (embryo), 45% in polished rice and 15% in chaff averagely

  17. Recovery of nitrogen fertilizer by traditional and improved rice cultivars in the Bhutan Highlands

    DEFF Research Database (Denmark)

    Ghaley, Bhim Bahadur; Jensen, Henning Høgh; Christiansen, Jørgen Lindskrog

    2010-01-01

    The recovery of soil derived nitrogen (NDFS) and fertilizer N (NDFF) was investigated in highland rice (Oryza sativa L.) fields in Bhutan, characterized by high inputs of farmyard manure (FYM). The effect of 60 kg N ha-1 (60 N) applied in two splits to a traditional and an improved cultivar......% respectively, with no difference between cultivars, but REN decreased with increasing FYM inputs. Fertilizer N recommendations that allow for previous FYM inputs combined with applications timed to coincide with maximum crop demand (45 DAT), and the use of improved cultivars, could enhance N fertilizer......, popular among the farmers, was investigated using the 15N isotope dilution technique. No differences were found between cultivars with respect to the uptake of NDFS and NDFF, but the improved cultivar yielded 27% more (P¿=¿0.05) grain compared with the traditional cultivar. This was largely due to its...

  18. Effect of Xanthan, Mono-di-Glyceride and Cultivar on Physical and Sensory Properties of Canned Rice During Storage

    Directory of Open Access Journals (Sweden)

    A. Nasirpour

    2014-08-01

    Full Text Available Ready-to-eat or canned products have an important place in urban life style. Rice is consumed by half of world population. Problems related to production of canned rice are the coherences of rice kernel, retrogradation of rice starch and physico-chemical changes of rice during storage. Main factors affecting physico-chemical properties of canned rice are rice cultivar, amylose and amylopectin content of kernels, precooking conditions, kernel composition and added stabilizers. In this study, effect of three cultivars, Basmati and two local cultivars, Tarom Mazandaran and Tarom Hashemi, also two types of stabilizers, Xanthan, Mono-di-glyceride, on sensory and physical properties of canned rice were studied. Type and level of stabilizers, cultivars and time had significant effect on texture of cooked rice. Initially during storage, Basmati had the highest firmness and Tarom Mazandaran and Tarom Hashemi had lower firmness. The results of texture analysis indicated that both stabilizers reduced firmness of cooked rice during storage. Adding xhanthan as stabilizer had higher effect on reducing of cooked rice firmness comparing to mono-di-glyceride. Result of color analysis showed that Basmati cultivar was most yellowish and Tarom Mazandaran indicated maximum lightness. Sensory analysis of samples indicated that Basmati had the best score on texture, appearance and acceptability and Tarom Hashemi had the best score on taste and flavor. Type of stabilizer had significant effect on taste and flavor of cooked rice.

  19. Biochemical and physiological characterization of three rice cultivars under different daytime temperature conditions

    Directory of Open Access Journals (Sweden)

    Alefsi David Sanchez-Reinoso

    2014-12-01

    Full Text Available Heat stress due to high daytime temperatures is one of the main limiting factors in rice (Oryza sativa L. yield in Colombia. Thus, the objective of the present research was to analyze the effect of three different daytime temperatures (25, 35, and 40 °C on the physiological responses of three Colombian rice cultivars (F60, F733, and F473, thereby contributing to the knowledge of rice acclimation mechanisms. For 10 d, eight plants of each of the three cultivars were subjected daily to 5 h periods of 35 and 40 °C. The control treatment corresponded to normal growth conditions (25 °C. Thermal stress was assessed based on a series of physiological and biochemical parameters. The 35 °C treatment produced photosynthetic and respiratory differences in all three cultivars. At 40 °C, 'F60' displayed the lowest photosynthetic rate and the highest respiratory rate. Although this cultivar experienced particularly strong electrolyte leakage and changes in proline when subjected to the high-temperature treatments, similar trends were observed in 'F733' and 'F473'. At 40 °C, the concentration of malondialdehyde (MDA was lower in 'F473' than in the other cultivars. These results may explain the poor agronomic performance of 'F60' in the field under daytime heat stress. The methodologies employed in the present work may be useful in Colombian rice breeding programs, particularly for the selection of heat-tolerant breeding stocks.

  20. Boron application improves yield of rice cultivars under high temperature stress during vegetative and reproductive stages.

    Science.gov (United States)

    Shahid, Mohammad; Nayak, Amaresh Kumar; Tripathi, Rahul; Katara, Jawahar Lal; Bihari, Priyanka; Lal, Banwari; Gautam, Priyanka

    2018-04-12

    It is reported that high temperatures (HT) would cause a marked decrease in world rice production. In tropical regions, high temperatures are a constraint to rice production and the most damaging effect is on spikelet sterility. Boron (B) plays a very important role in the cell wall formation, sugar translocation, and reproduction of the rice crop and could play an important role in alleviating high temperature stress. A pot culture experiment was conducted to study the effect of B application on high temperature tolerance of rice cultivars in B-deficient soil. The treatments comprised of four boron application treatments viz. control (B0), soil application of 1 kg B ha -1 (B1), soil application of 2 kg B ha -1 (B2), and foliar spray of 0.2% B (Bfs); three rice cultivars viz. Annapurna (HT stress tolerant), Naveen, and Shatabdi (both HT stress susceptible); and three temperature regimes viz. ambient (AT), HT at vegetative stage (HTV), and HT at reproductive stage (HTR). The results revealed that high temperature stress during vegetative or flowering stage reduced grain yield of rice cultivars mainly because of low pollen viability and spikelet fertility. The effects of high temperature on the spikelet fertility and grain filling varied among cultivars and the growth stages of plant when exposed to the high temperature stress. Under high temperature stress, the tolerant cultivar displays higher cell membrane stability, less accumulation of osmolytes, more antioxidant enzyme activities, and higher pollen viability and spikelet fertility than the susceptible cultivars. In the present work, soil application of boron was effective in reducing the negative effects of high temperature both at vegetative and reproductive stages. Application of B results into higher grain yield under both ambient and high temperature condition over control for all the three cultivars; however, more increase was observed for the susceptible cultivar over the tolerant one. The results

  1. Boron application improves yield of rice cultivars under high temperature stress during vegetative and reproductive stages

    Science.gov (United States)

    Shahid, Mohammad; Nayak, Amaresh Kumar; Tripathi, Rahul; Katara, Jawahar Lal; Bihari, Priyanka; Lal, Banwari; Gautam, Priyanka

    2018-04-01

    It is reported that high temperatures (HT) would cause a marked decrease in world rice production. In tropical regions, high temperatures are a constraint to rice production and the most damaging effect is on spikelet sterility. Boron (B) plays a very important role in the cell wall formation, sugar translocation, and reproduction of the rice crop and could play an important role in alleviating high temperature stress. A pot culture experiment was conducted to study the effect of B application on high temperature tolerance of rice cultivars in B-deficient soil. The treatments comprised of four boron application treatments viz. control (B0), soil application of 1 kg B ha-1 (B1), soil application of 2 kg B ha-1 (B2), and foliar spray of 0.2% B (Bfs); three rice cultivars viz. Annapurna (HT stress tolerant), Naveen, and Shatabdi (both HT stress susceptible); and three temperature regimes viz. ambient (AT), HT at vegetative stage (HTV), and HT at reproductive stage (HTR). The results revealed that high temperature stress during vegetative or flowering stage reduced grain yield of rice cultivars mainly because of low pollen viability and spikelet fertility. The effects of high temperature on the spikelet fertility and grain filling varied among cultivars and the growth stages of plant when exposed to the high temperature stress. Under high temperature stress, the tolerant cultivar displays higher cell membrane stability, less accumulation of osmolytes, more antioxidant enzyme activities, and higher pollen viability and spikelet fertility than the susceptible cultivars. In the present work, soil application of boron was effective in reducing the negative effects of high temperature both at vegetative and reproductive stages. Application of B results into higher grain yield under both ambient and high temperature condition over control for all the three cultivars; however, more increase was observed for the susceptible cultivar over the tolerant one. The results suggest

  2. Genetic dissection of grain traits in Yamadanishiki, an excellent sake-brewing rice cultivar.

    Science.gov (United States)

    Okada, Satoshi; Suehiro, Miki; Ebana, Kaworu; Hori, Kiyosumi; Onogi, Akio; Iwata, Hiroyoshi; Yamasaki, Masanori

    2017-12-01

    The grain traits of Yamadanishiki, an excellent sake-brewing rice cultivar in Japan, are governed by multiple QTLs, namely, a total of 42 QTLs including six major QTLs. Japanese rice wine (sake) is produced using brewing rice (Oryza sativa L.) that carries traits desirable for sake-brewing, such as a larger grain size and higher white-core expression rate (WCE) compared to cooking rice cultivars. However, the genetic basis for these traits in brewing rice cultivars is still unclear. We performed analyses of quantitative trait locus (QTL) of grain and days to heading over 3 years on populations derived from crosses between Koshihikari, a cooking rice, and Yamadanishiki, an excellent sake-brewing rice. A total of 42 QTLs were detected for the grain traits, and the Yamadanishiki alleles at 16 QTLs contributed to larger grain size. Two major QTLs essential for regulating both 100-grain weight (GWt) and grain width (GWh) were harbored in the same regions on chromosomes 5 and 10. An interaction was noted between the environment and the QTL associated with WCE on chromosome 6, which was detected in two of 3 years. In addition, two QTLs for WCE on chromosomes 3 and 10 overlapped with the QTLs for GWt and GWh, suggesting that QTLs associated with grain size also play an important role in the formation of white-core. Despite differences in the rate of grain growth in both Koshihikari and Yamadanishiki across 2 years, the WCE in Yamadanishiki remained consistent, thus demonstrating that the formation of white-core does not depend on grain filling speed. These data can be informative for programs involved in breeding better cooking and brewing rice cultivars.

  3. Differences in phytoalexin response among rice cultivars of different resistance to blast

    International Nuclear Information System (INIS)

    Dillon, V.M.; Overton, J.; Grayer, R.J.; Harborne, J.B.

    1997-01-01

    he production of both flavonoid and diterpenoid phytoalexins after induction by UV irradiation was studied in five rice genotypes of different susceptibility to the rice blast fungus Pyricularia oryzae. Consistent qualitative and quatitative differences were found between the rice cultivars in the phytoalexins produced, and there was a strong correlation between the accumulation of the phytoalexins, sakuranetin, momilactone A and oryzalexin S, and rice resistance to blast. Production of phytoalexins was also investigated in rice genotype Tetep after inoculation with an incompatible race of P. oryzae. Similar levels of sakuranetin and oryzalexin E were formed 3 days after both inoculation and UV irradiation of the leaves, but there were different levels of momilactone A and the other oryzalexins. Although a given rice genotype may respond quite differently in its production of phytoalexins depending on whether it has been irradiated or inoculated with a fungus, and in the latter case on whether a compatible race of the pathogen has been used, the present results indicate that genetic differences in phytoalexin response between rice cultivars are likely to play an important role among the many factors that determine differences in blast resistance between different rice genotypes. (author)

  4. Hybrid male sterility in rice controlled by interaction between divergent alleles of two adjacent genes.

    Science.gov (United States)

    Long, Yunming; Zhao, Lifeng; Niu, Baixiao; Su, Jing; Wu, Hao; Chen, Yuanling; Zhang, Qunyu; Guo, Jingxin; Zhuang, Chuxiong; Mei, Mantong; Xia, Jixing; Wang, Lan; Wu, Haibin; Liu, Yao-Guang

    2008-12-02

    Sterility is common in hybrids between divergent populations, such as the indica and japonica subspecies of Asian cultivated rice (Oryza sativa). Although multiple loci for plant hybrid sterility have been identified, it remains unknown how alleles of the loci interact at the molecular level. Here we show that a locus for indica-japonica hybrid male sterility, Sa, comprises two adjacent genes, SaM and SaF, encoding a small ubiquitin-like modifier E3 ligase-like protein and an F-box protein, respectively. Most indica cultivars contain a haplotype SaM(+)SaF(+), whereas all japonica cultivars have SaM(-)SaF(-) that diverged by nucleotide variations in wild rice. Male semi-sterility in this heterozygous complex locus is caused by abortion of pollen carrying SaM(-). This allele-specific gamete elimination results from a selective interaction of SaF(+) with SaM(-), a truncated protein, but not with SaM(+) because of the presence of an inhibitory domain, although SaM(+) is required for this male sterility. Lack of any one of the three alleles in recombinant plants does not produce male sterility. We propose a two-gene/three-component interaction model for this hybrid male sterility system. The findings have implications for overcoming male sterility in inter-subspecific hybrid rice breeding.

  5. Effects of ozone on growth, yield and leaf gas exchange rates of four Bangladeshi cultivars of rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    Akhtar, Nahid; Yamaguchi, Masahiro; Inada, Hidetoshi; Hoshino, Daiki; Kondo, Taisuke; Fukami, Motohiro; Funada, Ryo; Izuta, Takeshi

    2010-01-01

    To assess the effects of tropospheric O 3 on rice cultivated in Bangladesh, four Bangladeshi cultivars (BR11, BR14, BR28 and BR29) of rice (Oryza sativa L.) were exposed daily to charcoal-filtered air or O 3 at 60 and 100 nl l -1 (10:00-17:00) from 1 July to 28 November 2008. The whole-plant dry mass and grain yield per plant of the four cultivars were significantly reduced by the exposure to O 3 . The exposure to O 3 significantly reduced net photosynthetic rate of the 12th and flag leaves of the four cultivars. The sensitivity to O 3 of growth, yield and leaf gas exchange rates was not significantly different among the four cultivars. The present study suggests that the sensitivity to O 3 of yield of the four Bangladeshi rice cultivars is greater than that of American rice cultivars and is similar to that of Japanese rice cultivars and that O 3 may detrimentally affect rice production in Bangladesh. - Bangladeshi cultivars of rice are sensitive to O 3 below 100 ppb.

  6. Malaysian weedy rice shows its true stripes: wild Oryza and elite rice cultivars shape agricultural weed evolution in Southeast Asia.

    Science.gov (United States)

    Song, Beng-Kah; Chuah, Tse-Seng; Tam, Sheh May; Olsen, Kenneth M

    2014-10-01

    Weedy rice is a close relative of domesticated rice (Oryza sativa) that competes aggressively with the crop and limits rice productivity worldwide. Most genetic studies of weedy rice have focused on populations in regions where no reproductively compatible wild Oryza species occur (North America, Europe and northern Asia). Here, we examined the population genetics of weedy rice in Malaysia, where wild rice (O. rufipogon) can be found growing in close proximity to cultivated and weedy rice. Using 375 accessions and a combined analysis of 24 neutral SSR loci and two rice domestication genes (sh4, controlling seed shattering, and Bh4, controlling hull colour), we addressed the following questions: (i) What is the relationship of Malaysian weedy rice to domesticated and wild rice, and to weedy rice strains in the USA? (ii) To what extent does the presence of O. rufipogon influence the genetic and phenotypic diversity of Malaysian weeds? (iii) What do the distributions of sh4 and Bh4 alleles and associated phenotypes reveal about the origin and contemporary evolution of Malaysian weedy rice? Our results reveal the following: independent evolutionary origins for Malaysian weeds and US strains, despite their very close phenotypic resemblance; wild-to-weed gene flow in Malaysian weed populations, including apparent adaptive introgression of seed-shattering alleles; and a prominent role for modern Malaysian cultivars in the origin and recent proliferation of Malaysian weeds. These findings suggest that the genetic complexity and adaptability of weedy crop relatives can be profoundly influenced by proximity to reproductively compatible wild and domesticated populations. © 2014 John Wiley & Sons Ltd.

  7. Physiological and biochemical parameters for evaluation and clustering of rice cultivars differing in salt tolerance at seedling stage

    Directory of Open Access Journals (Sweden)

    Sumitahnun Chunthaburee

    2016-07-01

    Full Text Available Salinity tolerance levels and physiological changes were evaluated for twelve rice cultivars, including four white rice and eight black glutinous rice cultivars, during their seedling stage in response to salinity stress at 100 mM NaCl. All the rice cultivars evaluated showed an apparent decrease in growth characteristics and chlorophyll accumulation under salinity stress. By contrast an increase in proline, hydrogen peroxide, peroxidase (POX activity and anthocyanins were observed for all cultivars. The K+/Na+ ratios evaluated for all rice cultivars were noted to be highly correlated with the salinity scores thus indicating that the K+/Na+ ratio serves as a reliable indicator of salt stress tolerance in rice. Principal component analysis (PCA based on physiological salt tolerance indexes could clearly distinguish rice cultivars into 4 salt tolerance clusters. Noteworthy, in comparison to the salt-sensitive ones, rice cultivars that possessed higher degrees of salt tolerance displayed more enhanced activity of catalase (CAT, a smaller increase in anthocyanin, hydrogen peroxide and proline content but a smaller drop in the K+/Na+ ratio and chlorophyll accumulation.

  8. Physiological and biochemical mechanisms of seed priming-induced chilling tolerance in rice cultivars

    Directory of Open Access Journals (Sweden)

    Saddam eHussain

    2016-02-01

    Full Text Available Rice belongs to tropical and subtropical environments and is extremely sensitive to chilling stress particularly during emergence and early stages of seedling development. Seed priming can be a good approach to enhance rice germination and stand establishment under chilling stress. The present study examined the role of different seed priming techniques viz., hydropriming, osmopriming, redox priming, chemical priming, and hormonal priming, in enhancing the chilling tolerance in rice. The most effective reagents and their pre-optimized concentrations based on preliminary experiments were used in this study. Two different rice cultivars were sown under chilling stress (18˚C and normal temperatures (28˚C in separate growth chambers. A non-primed control treatment was also maintained for comparison. Chilling stress caused erratic and delayed germination, poor seedling growth, reduced starch metabolism and lower respiration rate, while higher lipid peroxidation and hydrogen peroxide accumulation in rice seedlings of both cultivars. Nevertheless, all the seed priming treatments effectively alleviated the negative effects of chilling stress. In addition, seed priming treatments triggered the activities of superoxide dismutase, peroxidase, and catalase, and enhanced the accumulations of glutathione and free proline in rice seedlings, which suggests that these measures help prevent the rice seedlings from chilling induced oxidative stress. Chemical priming with selenium and hormonal priming with salicylic acid remained more effective treatments for both rice cultivars under chilling stress than all other priming treatments. The better performance and greater tolerance of primed rice seedlings was associated with enhanced starch metabolism, high respiration rate, lower lipid peroxidation, and strong antioxidative defense system under chilling stress.

  9. Can simulation models help design rice cultivars that are more competitive against weeds?

    NARCIS (Netherlands)

    Bastiaans, L.; Kropff, M.J.; Kempuchetty, N.; Rajan, A.; Migo, T.R.

    1997-01-01

    Differences in competitive ability between rice cultivars IR8 and Mahsuri, grown in well-fertilised irrigated conditions, were analysed by means of a mechanistic simulation model (INTERCOM) for crop-weed interaction. The analysis revealed that the greater competitive ability of Mahsuri was due

  10. Cultivar difference in physicochemical properties of starches and flours from temperate rice of Indian Himalayas.

    Science.gov (United States)

    Mir, Shabir Ahmad; Bosco, Sowriappan John Don

    2014-08-15

    Starch and flour of seven temperate rice cultivars grown in Himalayan region were evaluated for composition, granule structure, crystallinity, Raman spectrometry, turbidity, swelling power, solubility, pasting properties and textural properties. The rice cultivars showed medium to high amylose content for starch (24.69-32.76%) and flour (17.78-24.86%). SKAU-382 showed the highest amount of amylose (32.76%). Rice starch showed polyhedral granule shapes and differences in their mean granule size (2.3-6.5 μm) were noted among the samples. The starch and flour samples showed type A-pattern with strong reflection at 15, 18, and 23. Pasting profile and textural analysis of rice starch and flour showed that all the cultivars differences, probably due to variation in amylose content. The present study can be used for identifying differences between rice genotypes for starch and flour quality and could provide guidance to possible industries for their end use. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Effects of Interaction between Cadmium (Cd) and Selenium (Se) on Grain Yield and Cd and Se Accumulation in a Hybrid Rice (Oryza sativa) System.

    Science.gov (United States)

    Huang, Baifei; Xin, Junliang; Dai, Hongwen; Zhou, Wenjing

    2017-11-01

    A pot experiment was conducted to investigate the interactive effects of cadmium (Cd) and selenium (Se) on their accumulation in three rice cultivars, which remains unclear. The results showed that Se reduced Cd-induced growth inhibition, and increased and decreased Se and Cd concentrations in brown rice, respectively. Cadmium concentrations in all tissues of the hybrid were similar to those in its male parent yet significantly lower than those in its female parent. Selenium reduced Cd accumulation in rice when Cd concentration exceeded 2.0 mg kg -1 ; however Se accumulation depended on the levels of Cd exposure. Finally, Cd had minimal effect on Se translocation within the three cultivars. We concluded that Cd concentration in brown rice is a heritable trait, making crossbreeding a feasible method for cultivating high-yield, low-Cd rice cultivars. Selenium effectively decreased the toxicity and accumulation of Cd, and Cd affected Se uptake but not translocation.

  12. Farmers' perception of risk in cultivating hybrid rice in Bangladesh ...

    African Journals Online (AJOL)

    Although there is an enormous potential for improving adoption of hybrid rice in Bangladesh, it is going through some difficulties in practice. Understanding farmers' perception about difficulties is critical to successful promotion. The present study was conducted to analyze farmers' perception of risk in cultivating hybrid rice ...

  13. DNA methylation polymorphism in a set of elite rice cultivars and its possible contribution to inter-cultivar differential gene expression.

    Science.gov (United States)

    Wang, Yongming; Lin, Xiuyun; Dong, Bo; Wang, Yingdian; Liu, Bao

    2004-01-01

    RAPD (randomly amplified polymorphic DNA) and ISSR (inter-simple sequence repeat) fingerprinting on HpaII/MspI-digested genomic DNA of nine elite japonica rice cultivars implies inter-cultivar DNA methylation polymorphism. Using both DNA fragments isolated from RAPD or ISSR gels and selected low-copy sequences as probes, methylation-sensitive Southern blot analysis confirms the existence of extensive DNA methylation polymorphism in both genes and DNA repeats among the rice cultivars. The cultivar-specific methylation patterns are stably maintained, and can be used as reliable molecular markers. Transcriptional analysis of four selected sequences (RdRP, AC9, HSP90 and MMR) on leaves and roots from normal and 5-azacytidine-treated seedlings of three representative cultivars shows an association between the transcriptional activity of one of the genes, the mismatch repair (MMR) gene, and its CG methylation patterns.

  14. Efficacy of Selected Insecticides Applied to Hybrid Rice Seed

    Science.gov (United States)

    Adams, A.; Gore, J.; Musser, F.; Cook, D.; Walker, T.; Dobbins, C.

    2016-01-01

    Hybrid rice and insecticide seed treatments targeting rice water weevil, Lissorhoptrus oryzophilus Kuschel, have altered the landscape of rice production. The effect of reduced seeding rates on seed treatment efficacy in hybrid rice has not been studied. During 2011 and 2012, an experiment was conducted at seven locations to determine the relationship between low seeding rates used in hybrid rice and efficacy of selected insecticidal seed treatments as measured by rice water weevil densities and yield. Labeled rates of thiamethoxam, chlorantraniliprole, and clothianidin were compared with higher rates of these products to determine if labeled rates provide an acceptable level of control of the rice water weevil. Study locations were divided into low, moderate, and high groups based on rice water weevil larval densities. All seed treatments and seed treatment rates reduced rice water weevil densities. However, there was no observed yield or economic benefit from the use of an insecticidal seed treatment in areas of low pressure. Differences in yield were observed among seed treatments and seed treatment rates in moderate and high pressure locations, and all seed treatments yielded better than the untreated plots, but these differences were not always economical. All seed treatments showed an economic advantage in areas of high weevil pressure, and there were no differences among seed treatment products or rates, suggesting that currently labeled seed treatment rates in hybrid rice are effective for rice water weevil management. PMID:26537671

  15. Identification and Characterization of Differentially Expressed Genes in Inferior and Superior Spikelets of Rice Cultivars with Contrasting Panicle-Compactness and Grain-Filling Properties.

    Directory of Open Access Journals (Sweden)

    Sudhanshu Sekhar

    Full Text Available Breeding programs for increasing spikelet number in rice have resulted in compactness of the panicle, accompanied by poor grain filling in inferior spikelets. Although the inefficient utilization of assimilate has been indicated as responsible for this poor grain filling, the underlying cause remains elusive. The current study utilized the suppression subtractive hybridization technique to identify 57 and 79 genes that overexpressed in the superior and inferior spikelets (with respect to each other, respectively, of the compact-panicle rice cultivar Mahalaxmi. Functional categorization of these differentially expressed genes revealed a marked metabolic difference between the spikelets according to their spatial location on the panicle. The expression of genes encoding seed storage proteins was dominant in inferior spikelets, whereas genes encoding regulatory proteins, such as serine-threonine kinase, zinc finger protein and E3 ligase, were highly expressed in superior spikelets. The expression patterns of these genes in the inferior and superior spikelets of Mahalaxmi were similar to those observed in another compact-panicle cultivar, OR-1918, but differed from those obtained in two lax-panicle cultivars, Upahar and Lalat. The results first suggest that the regulatory proteins abundantly expressed in the superior spikelets of compact-panicle cultivars and in both the superior and inferior spikelets of lax-panicle cultivars but poorly expressed in the inferior spikelets of compact-panicle cultivars promote grain filling. Second, the high expression of seed-storage proteins observed in the inferior spikelets of compact-panicle cultivars appears to inhibit the grain filling process. Third, the low expression of enzymes of the Krebs cycle in inferior spikelets compared with superior spikelets of compact-panicle cultivars is bound to lead to poor ATP generation in the former and consequently limit starch biosynthesis, an ATP-consuming process

  16. Divergent Responses of the Diazotrophic Microbiome to Elevated CO2 in Two Rice Cultivars

    Directory of Open Access Journals (Sweden)

    Yongjie Yu

    2018-06-01

    Full Text Available The species-specific responses of plant growth to elevated atmospheric CO2 concentration (eCO2 could lead to N limitation and potentially influence the sustainability of ecosystem. Questions remain unanswered with regards to the response of soil N2-fixing community to eCO2 when developing high-yielding agroecosystem to dampen the future rate of increase in CO2 levels and associated climate warming. This study demonstrates the divergent eCO2 influences on the paddy diazotrophic community between weak- and strong-responsive rice cultivars. In response to eCO2, the diazotrophic abundance increased more for the strong-responsive cultivar treatments than for the weak-responsive ones. Only the strong-responsive cultivars decreased the alpha diversity and separated the composition of diazotrophic communities in response to eCO2. The topological indices of the ecological networks further highlighted the different co-occurrence patterns of the diazotrophic microbiome in rice cultivars under eCO2. Strong-responsive cultivars destabilized the diazotrophic community by complicating and centralizing the co-occurrence network as well as by shifting the hub species from Bradyrhizobium to Dechloromonas in response to eCO2. On the contrary, the network pattern of the weak-responsive cultivars was simplified and decentralized in response to eCO2, with the hub species shifting from Halorhodospira under aCO2 to Sideroxydans under eCO2. Collectively, the above information indicates that the strong-responsive cultivars could potentially undermine the belowground ecosystem from the diazotrophs perspective in response to eCO2. This information highlights that more attention should be paid to the stability of the belowground ecosystem when developing agricultural strategies to adapt prospective climatic scenarios by growing high-yielding crop cultivars under eCO2.

  17. Interspecific hybridization among cultivars of hardy Hibiscus species section Muenchhusia

    DEFF Research Database (Denmark)

    Kuligowska, Katarzyna; Lütken, Henrik Vlk; Christensen, Brian

    2016-01-01

    Rose mallows belong to the Muenchhusia section of the Hibiscus genus. They represent a small group of cold tolerant North American plants and are popular ornamentals mainly because of their abundant, large and colorful flowers. Due to their geographical origin they are well suited for garden use...... in temperate regions worldwide. The aim of the study was to investigate hybridization barriers in crosses among cultivars of Hibiscus species from the Muenchhusia section: H. coccineus, H. laevis and H. moscheutos. Crossing barriers were identified as both pre- and post-zygotic. The analysis of pollen tube...

  18. NAL1 allele from a rice landrace greatly increases yield in modern indica cultivars.

    Science.gov (United States)

    Fujita, Daisuke; Trijatmiko, Kurniawan Rudi; Tagle, Analiza Grubanzo; Sapasap, Maria Veronica; Koide, Yohei; Sasaki, Kazuhiro; Tsakirpaloglou, Nikolaos; Gannaban, Ritchel Bueno; Nishimura, Takeshi; Yanagihara, Seiji; Fukuta, Yoshimichi; Koshiba, Tomokazu; Slamet-Loedin, Inez Hortense; Ishimaru, Tsutomu; Kobayashi, Nobuya

    2013-12-17

    Increasing crop production is essential for securing the future food supply in developing countries in Asia and Africa as economies and populations grow. However, although the Green Revolution led to increased grain production in the 1960s, no major advances have been made in increasing yield potential in rice since then. In this study, we identified a gene, SPIKELET NUMBER (SPIKE), from a tropical japonica rice landrace that enhances the grain productivity of indica cultivars through pleiotropic effects on plant architecture. Map-based cloning revealed that SPIKE was identical to NARROW LEAF1 (NAL1), which has been reported to control vein pattern in leaf. Phenotypic analyses of a near-isogenic line of a popular indica cultivar, IR64, and overexpressor lines revealed increases in spikelet number, leaf size, root system, and the number of vascular bundles, indicating the enhancement of source size and translocation capacity as well as sink size. The near-isogenic line achieved 13-36% yield increase without any negative effect on grain appearance. Expression analysis revealed that the gene was expressed in all cell types: panicles, leaves, roots, and culms supporting the pleiotropic effects on plant architecture. Furthermore, SPIKE increased grain yield by 18% in the recently released indica cultivar IRRI146, and increased spikelet number in the genetic background of other popular indica cultivars. The use of SPIKE in rice breeding could contribute to food security in indica-growing regions such as South and Southeast Asia.

  19. Genetic variation of 12 rice cultivars grown in Brunei Darussalam ...

    African Journals Online (AJOL)

    Dell

    2015-03-25

    Mar 25, 2015 ... Quantum yield for B. berminyak were unaffected and it showed the least reduction in growth parameters studied when expose to salinity stress. From both salinity tolerance and genetic variation investigations for these 12 cultivars, it may probably be better to intercross between Arat (moderately tolerant) ...

  20. Root Morphology Was Improved in a Late-Stage Vigor Super Rice Cultivar.

    Science.gov (United States)

    Huang, Min; Chen, Jiana; Cao, Fangbo; Jiang, Ligeng; Zou, Yingbin

    2015-01-01

    This study aimed to test the hypothesis that root morphology might be improved and consequently contributing to superior post-heading shoot growth and grain yield in late-stage vigor super rice. A pot experiment was carried out to compare yield attributes, shoot growth and physiological properties and root morphological traits between a late-stage vigor super rice cultivar (Y-liangyou 087) and an elite rice cultivar (Teyou 838). Grain yield and total shoot biomass were 7-9% higher in Y-liangyou 087 than in Teyou 838. Y-liangyou 087 had 60-64% higher post-heading shoot growth rate and biomass production than Teyou 838. Average relative chlorophyll concentration and net photosynthetic rate in flag leaves were 7-11% higher in Y-liangyou 087 than in Teyou 838 during heading to 25 days after heading. Y-liangyou 087 had 41% higher post-heading shoot N uptake but 17-25% lower root biomass and root-shoot ratio at heading and maturity than Teyou 838. Specific root length and length and surface area of fine roots were higher in Y-liangyou 087 than in Teyou 838 at heading and maturity by more than 15%. These results indicated that root-shoot relationships were well balanced during post-heading phase in the late-stage vigor super rice cultivar Y-liangyou 087 by improving root morphology including avoiding a too great root biomass and developing a large fine root system.

  1. Genetic analysis of basmati and non-basmati Pakistani rice (oryza sativa l.) cultivars using microsatellite markers

    International Nuclear Information System (INIS)

    Rabbani, M.A.; Masood, M.A.; Shinwari, Z.K.

    2010-01-01

    Information of genetic variability and relatedness among rice genotypes is essential for future breeding programmes and derivation of superior cultivars. The objective of the present study was to evaluate the genetic relationship among traditional and improved cultivars of Pakistani rice and to determine differences in the patterns of variation between two indica rice groups: basmati and nonbasmati. Forty-one cultivars were evaluated by means of 30 microsatellite markers distributed over the whole rice genome. A total of 104 alleles were detected by 30 markers, all of them (100%) were polymorphic. The number of alleles generated by each marker ranged from 2 to 6 with an average of 3.5 alleles marker-1. Polymorphism information content (PIC) varied from 0.259 to 0.782 with an average of 0.571. A significant positive correlation (r = 0.71) was found between the number of alleles at SSR locus and the PIC values. Pair-wise Nei and Li's similarity coefficients ranged from 0.10 to 0.99. A dendrogram based on cluster analysis by microsatellite polymorphism grouped 41 rice cultivars into 2 major groups effectively differentiating the late maturing, tall and slender-grain basmati and other aromatic rice cultivars from the early, short statured, short bold and long bold grain non-aromatic cultivars. Higher level of genetic diversity between basmati and non-basmati support the concept that former had a long history of independent evolution and diverged from nonbasmati rice a long time ago through human selection and patronage. Present investigation further indicated that genetically basmati rice is different from that of coarse indica and japonica type. The results suggested that microsatellite markers could efficiently be utilized for diversity analysis, and differentiation of basmati and non-basmati rice cultivars. In addition, marker-based identification of traditional basmati rice may help in maintaining the integrity of this high quality product to the benefit of both

  2. Asian wild rice is a hybrid swarm with extensive gene flow and feralization from domesticated rice.

    Science.gov (United States)

    Wang, Hongru; Vieira, Filipe G; Crawford, Jacob E; Chu, Chengcai; Nielsen, Rasmus

    2017-06-01

    The domestication history of rice remains controversial, with multiple studies reaching different conclusions regarding its origin(s). These studies have generally assumed that populations of living wild rice, O. rufipogon , are descendants of the ancestral population that gave rise to domesticated rice, but relatively little attention has been paid to the origins and history of wild rice itself. Here, we investigate the genetic ancestry of wild rice by analyzing a diverse panel of rice genomes consisting of 203 domesticated and 435 wild rice accessions. We show that most modern wild rice is heavily admixed with domesticated rice through both pollen- and seed-mediated gene flow. In fact, much presumed wild rice may simply represent different stages of feralized domesticated rice. In line with this hypothesis, many presumed wild rice varieties show remnants of the effects of selective sweeps in previously identified domestication genes, as well as evidence of recent selection in flowering genes possibly associated with the feralization process. Furthermore, there is a distinct geographical pattern of gene flow from aus , indica , and japonica varieties into colocated wild rice. We also show that admixture from aus and indica is more recent than gene flow from japonica , possibly consistent with an earlier spread of japonica varieties. We argue that wild rice populations should be considered a hybrid swarm, connected to domesticated rice by continuous and extensive gene flow. © 2017 Wang et al.; Published by Cold Spring Harbor Laboratory Press.

  3. Characterization and evaluation of rice blast resistance of Chinese indica hybrid rice parental lines

    Directory of Open Access Journals (Sweden)

    Yunyu Wu

    2017-12-01

    Full Text Available The development of resistant varieties and hybrid combinations has been the most effective and economical strategy to control blast disease caused by Magnaporthe oryzae. However, the distribution of major R genes and blast resistance characterization in hybrid rice parents has not been well investigated, resulting in their limited use in hybrid rice blast-resistance breeding. In the present study, 88 elite indica hybrid rice parental lines were evaluated with 30 isolates of M. oryzae collected from the main planting area of indica hybrid rice in China and were characterized for the presence of 11 major resistance genes using molecular markers. The pathogenicity assays showed that four types of hybrid rice parent line showed some resistance to M. oryzae. However, the proportions of highly resistant lines and the mean resistance frequency (RF varied among the four types, with resistance in decreasing order shown by three-line restorer lines, three-line maintainer lines, two-line sterile lines, and two-line restorer lines. All 88 hybrid rice parental lines carried more than one R gene, but none carried the R genes Pi1 and Pi2. Although Pid3 and Pi9 were present only in three-line restorer lines and Pigm only in three-line maintainer lines, the remaining six R genes (Pib, Pid2, Pi5, Pia, Pi54, and Pita were present in the four types of hybrid rice parent with significantly different distribution frequencies. The correlation between R genes and resistance reactions was investigated. The results are expected to provide useful information for rational utilization of major R genes in hybrid rice breeding programs. Keywords: Hybrid rice parental lines, Magnaporthe oryzae, Pi genes, Resistance evaluation, Molecular markers

  4. Differences in the Sensitivity to UVB Radiation of Two Cultivars of Rice (Oryza sativa L.)

    OpenAIRE

    Jun, Hidema; Hye-Sook, Kang; Tadashi, Kumagai; Institute of Genetic Ecology, Tohoku University; Institute of Genetic Ecology, Tohoku University; Institute of Genetic Ecology, Tohoku University

    1996-01-01

    The effects of UVB radiation on the growth of two cultivars of Japanese lowland rice (Oryza sativa L.), Sasanishiki and Norin 1, were examined in a phytotron. Supplementation of visible radiation with UVB radiation reduced plant length, tiller number, the fresh and dry weights of the aboveground parts of plants, and the amounts of total leaf nitrogen, chlorophyll, soluble protein and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in the eighth leaf, the youngest fully expanded leaf...

  5. Ancient rice cultivar extensively replaces phospholipids with non-phosphorus glycolipid under phosphorus deficiency.

    Science.gov (United States)

    Tawaraya, Keitaro; Honda, Soichiro; Cheng, Weiguo; Chuba, Masaru; Okazaki, Yozo; Saito, Kazuki; Oikawa, Akira; Maruyama, Hayato; Wasaki, Jun; Wagatsuma, Tadao

    2018-02-07

    Recycling of phosphorus (P) from P-containing metabolites is an adaptive strategy of plants to overcome soil P deficiency. This study was aimed at demonstrating differences in lipid remodelling between low-P-tolerant and -sensitive rice cultivars using lipidome profiling. The rice cultivars Akamai (low-P-tolerant) and Koshihikari (low-P-sensitive) were grown in a culture solution with [2 mg l -1 (+P)] or without (-P) phosphate for 21 and 28 days after transplantation. Upper and lower leaves were collected. Lipids were extracted from the leaves and their composition was analysed by liquid chromatography/mass spectrometry (LC-MS). Phospholipids, namely phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG) and phosphatidylinositol (PI), lysophosphatidylcholine (lysoPC), diacylglycerol (DAG), triacylglycerol (TAG) and glycolipids, namely sulfoquinovosyl diacylglycerol (SQDG), digalactosyldiacylglycerol (DGDG), monogalactosyldiacylglycerol (MGDG) and 1,2-diacyl-3-O-alpha-glucuronosyl glycerol (GlcADG), were detected. GlcADG level was higher in both cultivars grown in -P than in +P and the increase was larger in Akamai than in Koshihikari. DGDG, MGDG and SQDG levels were higher in Akamai grown in -P than in +P and the increase was larger in the upper leaves than in the lower leaves. PC, PE, PG and PI levels were lower in both cultivars grown in -P than in +P and the decrease was larger in the lower leaves than in the upper leaves and in Akamai than in Koshihikari. Akamai catabolised more phospholipids in older leaves and synthesised glycolipids in younger leaves. These results suggested that extensive phospholipid replacement with non-phosphorus glycolipids is a mechanism underlying low-P-tolerance in rice cultivars. © 2018 Scandinavian Plant Physiology Society.

  6. Genome-wide DNA polymorphisms in Kavuni, a traditional rice cultivar with nutritional and therapeutic properties.

    Science.gov (United States)

    Rathinasabapathi, Pasupathi; Purushothaman, Natarajan; Parani, Madasamy

    2016-05-01

    Although rice genome was sequenced in the year 2002, efforts in resequencing the large number of available accessions, landraces, traditional cultivars, and improved varieties of this important food crop are limited. We have initiated resequencing of the traditional cultivars from India. Kavuni is an important traditional rice cultivar from South India that attracts premium price for its nutritional and therapeutic properties. Whole-genome sequencing of Kavuni using Illumina platform and SNPs analysis using Nipponbare reference genome identified 1 150 711 SNPs of which 377 381 SNPs were located in the genic regions. Non-synonymous SNPs (62 708) were distributed in 19 251 genes, and their number varied between 1 and 115 per gene. Large-effect DNA polymorphisms (7769) were present in 3475 genes. Pathway mapping of these polymorphisms revealed the involvement of genes related to carbohydrate metabolism, translation, protein-folding, and cell death. Analysis of the starch biosynthesis related genes revealed that the granule-bound starch synthase I gene had T/G SNPs at the first intron/exon junction and a two-nucleotide combination, which were reported to favour high amylose content and low glycemic index. The present study provided a valuable genomics resource to study the rice varieties with nutritional and medicinal properties.

  7. Identification of rice cultivars with low brown rice mixed cadmium and lead contents and their interactions with the micronutrients iron, zinc, nickel and manganese.

    Science.gov (United States)

    Li, Bing; Wang, Xun; Qi, Xiaoli; Huang, Lu; Ye, Zhihong

    2012-01-01

    Paddy fields in mining areas are usually co-contaminated by a cocktail of mixed toxic heavy metals (e.g., Cd and Pb in Pb/Zn mines). However, previous studies on rice cultivars screened for effective metal exclusion have mostly focused on individual metals, and have been conducted under pot-trial or hydroponic solution conditions. This study identified rice cultivars with both low Cd and Pb accumulation under Cd- and Pb-contaminated field conditions, and the interactions of the toxic elements Cd and Pb with the micronutrient elements Fe, Zn, Mn and Ni were also studied. Among 32 rice cultivars tested, there were significant differences in Cd (0.06-0.59 mg/kg) and Pb (0.25-3.15 mg/kg) levels in their brown rice, and similar results were also found for the micronutrient elements. Significant decreases in concentrations of Fe and Mn were detected with increasing Cd concentrations and a significant elevation in Fe, Mn and Ni with increasing Pb concentrations. A similar result was also shown by Cd and Ni. Three cultivars were identified with a combination of low brown rice Cd and Pb, high micronutrient and grain yield (Wufengyou 2168, Tianyou 196 and Guinongzhan). Present results suggest that it is possible to breed rice cultivars with low mixed toxic element (Cd, Pb) and high micronutrient contents along with high grain yields, thus ensuring food safety and quality.

  8. Reaction of rice cultivars to a virulent Rice Yellow Mottle Virus strain ...

    African Journals Online (AJOL)

    Isolates of RYMV were collected from three “hot-spots” in Uganda (Lira, Luweero and Iganga). The isolate from Iganga was most virulent on RYMV susceptible cultivar (IR64), and thus used to constitute study treatment evaluated in the study. Cultivars were potted and raised in a screenhouse experiment arranged in a ...

  9. DNA tagging of blast resistant gene(s in three Brazilian rice cultivars

    Directory of Open Access Journals (Sweden)

    S.S. Sandhu

    2003-12-01

    Full Text Available Rice blast is the most important fungal disease of rice and is caused by Pyricularia oryzae Sacc. (Telomorph Magnoporthe grisea Barr.. Seven randomly amplified polymorphic DNA (RAPD markers OPA5, OPG17, OPG18, OPG19, OPF9, OPF17 and OPF19 showed very clear polymorphism in resistant cultivar lines which differed from susceptible lines. By comparing different susceptible lines, nine DNA amplifications of seven primers (OPA5(1000, OPA5(1200, OPG17(700, OPG18(850, OPG19(500, OPG19(600, OPF9(600, OPF17(1200 and OPF19(600 were identified as dominant markers for the blast resistant gene in resistant cultivar lines. These loci facilitate the indirect scoring of blast resistant and blast susceptible genotypes. The codomine RAPDs markers will facilitate marker-assisted selection of the blast resistant gene in two blast resistant genotypes of rice (Labelle and Line 11 and will be useful in rice breeding programs.

  10. Identification of rice cultivar with exclusive characteristic to Cd using a field-polluted soil and its foreground application.

    Science.gov (United States)

    Zhan, Jie; Wei, Shuhe; Niu, Rongcheng; Li, Yunmeng; Wang, Shanshan; Zhu, Jiangong

    2013-04-01

    Using low-accumulative plant, especially excluder crop, to safely produce food is one of the very important technologies of phytoremediation, which is practical to safe production and long-term remediation of heavy metal-contaminated soil. A pot experiment using field cadmium (Cd)-contaminated soil (Cd concentration was 0.75 mg kg(-1)) was conducted to compare Cd accumulation differences among 39 normal rice cultivars (Japonica) in Shenyang region of China for food safety and high grain yield aim. The results showed that brown grain Cd concentration in 12 rice cultivars of a total of 39 tested cultivars was lower than 0.2 mg kg(-1) (Agricultural Trade Standard of Nonpollution Food for Rice of China, NY 5115-2008). In these 12 cultivars, Cd enrichment factors (Cd concentration ratio in shoot to that in soil) of nine cultivars were lower than 1. Likewise, Cd translocation factors (Cd concentration ratio in shoot to that in root) of eight cultivars were lower than the 0.28 average. Furthermore, grain yield per pot of seven cultivars were higher than the average 18.4 g pot(-1). Four cultivars, i.e., Shendao 5, Tianfu 1, Fuhe 90, and Yanfeng 47 showed Cd-exclusive characteristic and better foreground application.

  11. Variation in Yield and Physicochemical Quality Traits among Mutants of Japonica Rice Cultivar Wuyujing 3

    Directory of Open Access Journals (Sweden)

    Jose Daniel Abacar

    2016-01-01

    Full Text Available To select elite germplasms, 112 mutants derived from japonica rice cultivar Wuyujing 3 were evaluated. The yield components such as panicle number per square meter, grain number per panicle, and grain weight were measured. The quality traits such as percentage of chalky grains (PCG, brown rice yield (BRY, milled rice yield (MRY, degree of milling (DM, amylose content (AC, protein content (PC, and relationships among traits were inverstigated. Results showed that grain yield ranged from 2.15 to 12.49 t/hm2 with a mean of 6.4 t/hm2 and number of grains per square meter contributed for 94.64% in grain yield variation. For quality traits, all rice mutants had short size (grain length ≤ 5.5 mm and bold shape (grain length to width ratio = 1.10–2.00. Most of rice mutants (87.5% had PCG values below 20%. All mutants had MRY values above 50%, AC values below 20%, and PC values below 10%. Percentage of chalky grains was significantly negatively correlated with MRY and positively correlated with DM. BRY and MRY were significantly negatively correlated with DM. PC was significantly and positively correlated with MRY and negatively correlated with DM, while AC had no significant correlation with these quality traits. It was concluded that there were 25 rice mutants which fulfilled the major requirements of Jiangsu standard japonica rice such as low percentage of chalky grains, low amylose content, optimal protein content, and which could be used as elite germplasms. Thus the mutants identified may lead to significant progress in improvement of rice quality.

  12. Root Morphology Was Improved in a Late-Stage Vigor Super Rice Cultivar.

    Directory of Open Access Journals (Sweden)

    Min Huang

    Full Text Available This study aimed to test the hypothesis that root morphology might be improved and consequently contributing to superior post-heading shoot growth and grain yield in late-stage vigor super rice. A pot experiment was carried out to compare yield attributes, shoot growth and physiological properties and root morphological traits between a late-stage vigor super rice cultivar (Y-liangyou 087 and an elite rice cultivar (Teyou 838. Grain yield and total shoot biomass were 7-9% higher in Y-liangyou 087 than in Teyou 838. Y-liangyou 087 had 60-64% higher post-heading shoot growth rate and biomass production than Teyou 838. Average relative chlorophyll concentration and net photosynthetic rate in flag leaves were 7-11% higher in Y-liangyou 087 than in Teyou 838 during heading to 25 days after heading. Y-liangyou 087 had 41% higher post-heading shoot N uptake but 17-25% lower root biomass and root-shoot ratio at heading and maturity than Teyou 838. Specific root length and length and surface area of fine roots were higher in Y-liangyou 087 than in Teyou 838 at heading and maturity by more than 15%. These results indicated that root-shoot relationships were well balanced during post-heading phase in the late-stage vigor super rice cultivar Y-liangyou 087 by improving root morphology including avoiding a too great root biomass and developing a large fine root system.

  13. Comparative Transcriptional Profiling of Three Super-Hybrid Rice Combinations

    Directory of Open Access Journals (Sweden)

    Yonggang Peng

    2014-03-01

    Full Text Available Utilization of heterosis has significantly increased rice yields. However, its mechanism remains unclear. In this study, comparative transcriptional profiles of three super-hybrid rice combinations, LY2163, LY2186 and LYP9, at the flowering and filling stages, were created using rice whole-genome oligonucleotide microarray. The LY2163, LY2186 and LYP9 hybrids yielded 1193, 1630 and 1046 differentially expressed genes (DGs, accounting for 3.2%, 4.4% and 2.8% of the total number of genes (36,926, respectively, after using the z-test (p < 0.01. Functional category analysis showed that the DGs in each hybrid combination were mainly classified into the carbohydrate metabolism and energy metabolism categories. Further analysis of the metabolic pathways showed that DGs were significantly enriched in the carbon fixation pathway (p < 0.01 for all three combinations. Over 80% of the DGs were located in rice quantitative trait loci (QTLs of the Gramene database, of which more than 90% were located in the yield related QTLs in all three combinations, which suggested that there was a correlation between DGs and rice heterosis. Pathway Studio analysis showed the presence of DGs in the circadian regulatory network of all three hybrid combinations, which suggested that the circadian clock had a role in rice heterosis. Our results provide information that can help to elucidate the molecular mechanism underlying rice heterosis.

  14. Variation among conventional cultivars could be used as a criterion for environmental safety assessment of Bt rice on nontarget arthropods

    Science.gov (United States)

    Wang, Fang; Dang, Cong; Chang, Xuefei; Tian, Junce; Lu, Zengbin; Chen, Yang; Ye, Gongyin

    2017-02-01

    The current difficulty facing risk evaluations of Bacillus thuringiensis (Bt) crops on nontarget arthropods (NTAs) is the lack of criteria for determining what represents unacceptable risk. In this study, we investigated the biological parameters in the laboratory and field population abundance of Nilaparvata lugens (Hemiptera: Delphacidae) on two Bt rice lines and the non-Bt parent, together with 14 other conventional rice cultivars. Significant difference were found in nymphal duration and fecundity of N. lugens fed on Bt rice KMD2, as well as field population density on 12 October, compared with non-Bt parent. However, compared with the variation among conventional rice cultivars, the variation of each parameter between Bt rice and the non-Bt parent was much smaller, which can be easily seen from low-high bar graphs and also the coefficient of variation value (C.V). The variation among conventional cultivars is proposed to be used as a criterion for the safety assessment of Bt rice on NTAs, particularly when statistically significant differences in several parameters are found between Bt rice and its non-Bt parent. Coefficient of variation is suggested as a promising parameter for ecological risk judgement of IRGM rice on NTAs.

  15. Leaf density explains variation in leaf mass per area in rice between cultivars and nitrogen treatments.

    Science.gov (United States)

    Xiong, Dongliang; Wang, Dan; Liu, Xi; Peng, Shaobing; Huang, Jianliang; Li, Yong

    2016-05-01

    Leaf mass per area (LMA) is an important leaf trait; however, correlations between LMA and leaf anatomical features and photosynthesis have not been fully investigated, especially in cereal crops. The objectives of this study were (a) to investigate the correlations between LMA and leaf anatomical traits; and (b) to clarify the response of LMA to nitrogen supply and its effect on photosynthetic nitrogen use efficiency (PNUE). In the present study, 11 rice varieties were pot grown under sufficient nitrogen (SN) conditions, and four selected rice cultivars were grown under low nitrogen (LN) conditions. Leaf anatomical traits, gas exchange and leaf N content were measured. There was large variation in LMA across selected rice varieties. Regression analysis showed that the variation in LMA was more closely related to leaf density (LD) than to leaf thickness (LT). LMA was positively related to the percentage of mesophyll tissue area (%mesophyll), negatively related to the percentage of epidermis tissue area (%epidermis) and unrelated to the percentage of vascular tissue area (%vascular). The response of LMA to N supplementation was dependent on the variety and was also mainly determined by the response of LD to N. Compared with SN, photosynthesis was significantly decreased under LN, while PNUE was increased. The increase in PNUE was more critical in rice cultivars with a higher LMA under SN supply. Leaf density is the major cause of the variation in LMA across rice varieties and N treatments, and an increase in LMA under high N conditions would aggravate the decrease in PNUE. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Breeding of a new early season indica rice variety Ganzaoxian 56 by irradiation, anther culture and hybridization

    International Nuclear Information System (INIS)

    Huang Yingjin; Liu Yibai; Kuang Huiyun; Xu Zhengjin

    2005-01-01

    Ganzaoxian 56 is a new early season indica rice variety, which was bred in the College of Agronomy of Jiangxi Agricultural University by the integrative breeding techniques of radiation, anther culture and hybridization. Its main characteristics were as follows: super quality, high yield, high tolerance to heat-forced maturity, suitable maturity and high resistance to rice blast. It was registered by Crop Cultivar Registration Committee of Jiangxi Province on March 19, 2004. The breeding process of Ganzaoxian 56, main characteristics and the value of its exploitation and application were described in this paper. (authors)

  17. Evaluation of methane emissions of some rice cultivars of Sri Lanka

    Energy Technology Data Exchange (ETDEWEB)

    Namaratne, S.Y.; Alwis, H.P.W. de [Institute of Fundamental Studies, Kandy (Sri Lanka)

    1996-12-31

    A field experiment on three local rice cultivars, namely BG 300, BG 304 and AT 303, showed no statistically significant difference (p<0.05) among them with-respect to the methane flux emitted. The methane flux profiles of all three varieties indicated a more or less constant emission during the vegetative and reproductive periods, a peak emission during late flowering/early ripening stage and a dramatic increase in the flux during the late ripening period. The seasonal methane flux of BG 300, BG 304 and AT 303 were 200 {+-} 48, 156 {+-} 52 and 129 {+-} 40 g m{sup {minus}2}, respectively for a 92 day cropping period.

  18. Nitrogen fertilizer management for tidal submergence tolerant landrace rice (Oryza sativa L. cultivars

    Directory of Open Access Journals (Sweden)

    M.A.A. Mamun

    2017-12-01

    Full Text Available In tidal submergence ecosystem, nitrogen (N is a crucial nutrient for improved and sustainable rice production. Therefore, a series of on-farm and on-station field experiments were conducted to develop a suitable N management practice for tidal submergence tolerant landrace aman rice. In on-farm, urea deep placement (UDP through urea super granule before panicle initiation (PI stage was compared with no fertilizer application. Similarly, five N fertilizer management practices viz. (i. two splits of prilled urea (PU, (ii. UDP at 10 DAT, (iii. UDP before PI, (iv. full dose PU before PI and (v. No urea (control were compared at on-station trial. Tidal submergence tolerance aman rice varieties (Rajashail, Kutiagni, Sadamota and Lalmota were used as testing materials. In on farm experiment, aman cultivars produced 2.0–2.5 t ha−1 grain without N fertilizer. But, cultivated Rajashail, Kutiagni, Sadachikon, Sadapajam, Lalmota and Sadamota gave 3.0–3.5 t ha−1 grain yield with the UDP before PI in tidal prone areas. Though UDP required fertilizer and application cost but it gave profit upto 22,000 BDT ha−1 (Bangladeshi Taka. In on-station experiment, UDP before PI stage significantly increased rice yield and economic return although it was comparable to two splits of PU and top dressing of PU before PI stage. However, UDP at 10 DAT increased straw yield but failed to increase grain yield even compared to control. It could be concluded that UDP before PI stage of rice is an effective method for increasing rice yield and farm income in tidal prone areas.

  19. Response of rice cultivars to rates of nitrogen and potassium application in field and pot conditions.

    Science.gov (United States)

    Bahmaniar, M A; Ranjbar, G A

    2007-05-01

    Nitrogen and potassium are the yield-limiting nutrients in rice production regions of Iran. Use of N and K efficient cultivars is an important complementary strategy in improving rice yield, increasing the quality properties of rice grains and reducing cost of production. In order to consider the effects of different amounts of N and K application on rice (Oryza sativa L.) yield and yield components in pot and field conditions these experiments were undertaken in 2004 at Sari Agricultural Station, Iran. Four levels of N (0, 50, 100 and 150 Kg N ha(-1) in field and 0, 0.6, 1.2 and 1.8 g N pot(-1) in pot) corresponding with four levels of K (0, 75, 150 and 225 kg K2O ha(-1) in field and 0, 0.5, 1 and 1.5 g K2O pot(-1) in pot) were applied in a split-factorial plot design with three replications in both pot and field experiments, variously. Grain yield, number of grain per panicle, number of tiller, plant height, length of flag leaf, total and shoot dry matter, 1000 grain weight and harvest index have been increased by N application in field conditions. However, in pot conditions grain yield, number of grain per panicle, number of tiller, plant height, width of flag leaf, total and shoot dry matter, leaf nitrogen contents and harvest index have significantly been increased (p pot conditions (p < or = 0.05).

  20. Characterization and Assessment of Flavor Compounds and Some Allergens in Three Iranian Rice Cultivars during Gelatinization Process by HS-SPME/GC-MS

    Directory of Open Access Journals (Sweden)

    M. H. Givianrad

    2012-01-01

    Full Text Available A combined gas chromatography mass spectrometry with headspace solid-phase microextraction method has been utilized for the analysis of the flavor volatiles of three different rice cultivars including two modified Iranian rice cultivars and Hashemi rice cultivar during gelatinization. As a result, while gelatinization would progress, the amount of the volatile compounds would be also increased. Altogether, 74, 55 and 66 components were identified for Hashemi, HD5 and HD6 rice samples, respectively, which 56 unique compounds were not identified, previously. Subsequently, seven fragrance chemicals have been detected, which were most frequently reported as contact allergens in the European Union.

  1. Eficiência produtiva de cultivares de arroz com divergência fenotípica Production efficiency of rice cultivars with phenotypic diversity

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    Cleber M. Guimarães

    2008-10-01

    Full Text Available O objetivo do trabalho foi avaliar, fenotipicamente, as cultivares de arroz tradicionais Guarani e Caiapó, e as modernas, CIRAD L(-141, Maravilha, BR IRGA 409 e Metica 1, por meio da associação entre os vários componentes da produtividade de grãos, para prover base de seleção genética em populações de plantas. O estudo foi conduzido na estação chuvosa do ano agrícola de 2003-2004, na área experimental da Embrapa Arroz e Feijão, em Santo Antônio de Goiás, GO. Em condições de sequeiro, com suplementação hídrica, as cultivares de arroz de terras altas CIRAD L(-141, Guarani, Caiapó e Maravilha, apresentaram maiores índices de colheita e menores percentagens de esterilidade de espiguetas que as de arroz irrigado BR IRGA 409 e Metica 1. Concluiu-se que a maior produção de biomassa pelas cultivares de arroz irrigado não se refletiu na produtividade de grãos. A CIRAD L(-141 por apresentar alta área foliar, panículas densas com alto número de grãos e um comportamento intermediário em todos os componentes avaliados, como índice de colheita, massa dos grãos, fertilidade de perfilhos, perfilhamento, esterilidade de espiguetas e taxa de crescimento, produziu 12,5% a mais que a segunda mais produtiva. O aumento do índice de colheita e da massa dos grãos e a redução da esterilidade das espiguetas devido às suas altas correlações com a produtividade, são considerados prioritários em programas de melhoramento de arroz que visem obter cultivares mais produtivas.The objective of this study was to phenotypically evaluate the traditional rice cultivars Guarani and Caiapó, and the modern rice cultivars CIRAD L(-141, Maravilha, BR IRGA 409, and Metica 1 through association among various yield components to establish a genetic selection base in plant population. The study was conducted during the rainy season of 2003-2004, at the Embrapa Rice & Beans experimental station, in Santo Antônio de Goiás, Goiás, Brazil. With

  2. Analysis and comparison of fragrant gene sequence in some rice cultivars

    Directory of Open Access Journals (Sweden)

    Karami Noushafarin

    2016-01-01

    Full Text Available It is known that the fragrant trait in rice (Oryza sativa L. is largely controlled by fgr gene on chromosome 8 and it has been specified that the existence of an 8 bp deletion and three single nucleotide polymorphism (SNP in exon 7 is effective on this trait. In this study, sequence alignment analysis of fgr exon7 on chromosome 8 for 11 different fragrant and non-fragrant cultivars revealed that 5 aromatic rice cultivars carried 3 SNPs and 8 bp deletion in exon7 which terminates prematurely at a TAA stop codon. However, 5 of the non-aromatics showed a sequence identical to the published Nipponbare, being non-fragrant Japonica variety sequence. An exception among them was Bejar, which had 8 bp deletion and 3SNPs but it was non-aromatic. Sequencing can determine nucleotide alignment of a gene and give beneficial information about gene function. In silico prediction showed proteins sequences alignment of fgr gene for Khazar and Domsiah genotypes were different. Betaine aldehyde dehydrogenase complete enzyme belongs to Khazar non-fragrant genotype that has complete length and 503 amino acids while non-functional BADH2 enzyme for Domsiah fragrant genotype has 251 amino acids that result in accumulate 2-acetyl-1-pyrroline (2AP and produces aroma in fragrant genotypes.

  3. Influência de cultivares de arroz e épocas da adubação nitrogenada nas relações de interferência da cultura com cultivar simulador de infestação de arroz-vermelho Influence of rice cultivars and nitrogen fertilizer timing on the interference relationships between the crop and cultivar simulating red rice infestation

    Directory of Open Access Journals (Sweden)

    D. Agostinetto

    2004-06-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos de cultivares de arroz irrigado e de épocas de adubação nitrogenada durante o ciclo da cultura sobre a habilidade competitiva do cereal em relação ao cultivar EEA 406, usado como simulador da planta daninha arrozvermelho. Para isso, conduziu-se experimento em campo, na estação de crescimento 2001/02. Os tratamentos, dispostos em esquema fatorial, constaram de cultivares de arroz (BRS-38 Ligeirinho, IRGA 417 e BR-IRGA 409, épocas de aplicação do nitrogênio (N (100% do N na semeadura, 50% do N na semeadura mais 50% no início da diferenciação da panícula (IDP, 100% no IDP e testemunha sem o adubo e populações do cultivar simulador do arroz-vermelho. Para relacionar as perdas de produtividade de grãos de arroz com populações do cultivar simulador, utilizou-se o modelo de regressão da hipérbole retangular, ajustado de modo independente para os fatores estudados. Verificou-se que a época de aplicação do N influenciou na habilidade competitiva dos cultivares de arroz. Cultivares de ciclo muito curto e curto apresentaram maior habilidade competitiva com o cultivar simulador, quando a adubação foi realizada na semeadura, enquanto o cultivar de ciclo médio se beneficiou do fracionamento da adubação na semeadura e no IDP.The objective of this study was to evaluate the effects of flooded rice cultivars and timings of nitrogen fertilizer application during the crop cycle on the competitive ability of this cereal in relation to EEA 406 cultivar, used as a mimicker of red rice. Thus, a field experiment was carried out during the 2001/02 growing season. The treatments were arranged in a factorial design,comprising the rice cultivars (BRS-38 Ligeirinho, IRGA 417, and BR-IRGA 409, nitrogen (N application timings (100% at sowing, 50% at sowing plus 50% at the beginning of panicle differentiation (BPD, 100% at BPD, and check without fertilizer, and densities of the mimicker cultivar. In

  4. Tagging microsatellite marker to a blast resistance gene in the irrigated rice cultivar Cica-8

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    Thiago Martins Pinheiro

    2012-09-01

    Full Text Available The rice cultivar Cica-8 exhibit differential reaction to several pathotypes of Magnaporthe oryzae. The objective of the present investigation was to determine the number of alleles involved in the expression of resistance to leaf blast and identify microsatellite markers linked to these alleles. A cross between cultivar Metica-1 and Cica-8 susceptible and resistant, respectively, to pathotype IB-1 (Py1049 was made to obtain F1, F2, BC1:1 and BC1:2 progenies. Greenhouse tests for leaf blast reaction showed that resistance is controlled by a monogenic dominant gene. For testing microsatellite markers, DNA of both resistant and susceptible parents and F1 and F2 populations was extracted. As expected for single dominant gene the F2 populations segregated at a ratio of 3:1. Of the 11 microsatellite markers tested, one marker RM 7102 was found to be closely linked to the resistant allele at a distance of 2.7 cM, in the cultivar Cica-8 to pathotype IB-1.

  5. Differences in the sensitivity to UVB radiation of two cultivars of rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    Hidema, J.; Kang, H.S.; Kumagai, T.

    1996-01-01

    The effects of UVB radiation on the growth of two cultivars of Japanese lowland rice (Oryza sativa L.), Sasanishiki and Norin 1, were examined in a phytotron. Supplementation of visible radiation with UVB radiation reduced plant length, tiller number, the fresh and dry weights of the aboveground parts of plants, an the amounts of total leaf nitrogen, chlorophyll, soluble protein and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) in the eight leaf, the youngest fully expanded leaf. By contrast, UVB radiation significantly increased the accumulation of UV-absorbing compounds. There was a difference between the two cultivars in the resistance to the effects of UVB radiation. The reduction in the amounts of Rubisco was smaller in Sasanishiki, while the increase in the accumulation of UV-absorbing compounds was greater in Sasanishiki. Parameters of plant growth, with the exception of the amount of Rubisco, decreased in direct proportion to decreases in total leaf nitrogen in plants grown under lower or the Rubisco content of Norin 1 grown under a high dose of UVB radiation was exceptionally marked, and was not observed similarly in Sasanishiki. The results suggest that the remarkable reduction in rubisco content in NOrin 1 might have been due to the specific effects of UVB radiation. It is also suggested that the difference between cultivars in the resistance to UVB radiation might be due to the differences in the levels of Rubisco and in UV-absorbing compounds that are induced by UVB radiation

  6. Reactive oxygen species dynamics in roots of salt sensitive and salt tolerant cultivars of rice.

    Science.gov (United States)

    Saini, Shivani; Kaur, Navdeep; Pati, Pratap Kumar

    2018-06-01

    Salinity stress is one of the major constraints for growth and survival of plants that affects rice productivity worldwide. Hence, in the present study, roots of two contrasting salinity sensitive cultivars, IR64 (IR64, salt sensitive) and Luna Suvarna (LS, salt tolerant) were compared with regard to the levels of reactive oxygen species (ROS) to derive clues for their differential salt stress adaptation mechanisms. In our investigation, the tolerant cultivar exhibited longer primary roots, more lateral roots, higher root number leading to increased root biomass, with respect to IR64. It was observed that LS roots maintained higher level of H 2 O 2 in comparison to IR64. The activities of various enzymes involved in enzymatic antioxidant defense mechanism (SOD, CAT, GPX, DHAR and MDHAR) were found to be greater in LS roots. Further, the higher transcript level accumulation of genes encoding ROS generating (RbohA, RbohD and RbohE) and scavenging enzymes (Fe-SOD, Chloroplastic Cu/Zn-SOD, CAT and DHAR) were noticed in the roots of tolerant cultivar, LS. Moreover, the content of other stress markers such as total protein and proline were also elevated in LS roots. While, the expression of proline biosynthesis gene (P5CS) and proline catabolism gene (PDH) was observed to be lower in LS. Copyright © 2018. Published by Elsevier Inc.

  7. An improved protocol for efficient transformation and regeneration of diverse indica rice cultivars

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    Sahoo Khirod K

    2011-12-01

    Full Text Available Abstract Background Rice genome sequencing projects have generated remarkable amount of information about genes and genome architecture having tremendous potential to be utilized in both basic and applied research. Success in transgenics is paving the way for preparing a road map of functional genomics which is expected to correlate action of a gene to a trait in cellular and organismal context. However, the lack of a simple and efficient method for transformation and regeneration is a major constraint for such studies in this important cereal crop. Results In the present study, we have developed an easy, rapid and highly efficient transformation and regeneration protocol using mature seeds as explants and found its successful applicability to a choice of elite indica rice genotypes. We have optimized various steps of transformation and standardized different components of the regeneration medium including growth hormones and the gelling agent. The modified regeneration medium triggers production of large number of shoots from smaller number of calli and promotes their faster growth, hence significantly advantageous over the existing protocols where the regeneration step requires maximum time. Using this protocol, significantly higher transformation efficiency (up to 46% and regeneration frequency (up to 92% for the untransformed calli and 59% for the transformed calli were achieved for the four tested cultivars. We have used this protocol to produce hundreds of independent transgenic lines of different indica rice genotypes. Upon maturity, these transgenic lines were fertile thereby indicating that faster regeneration during tissue culture did not affect their reproductive potential. Conclusions This speedy, yet less labor-intensive, protocol overcomes major limitations associated with genetic manipulation in rice. Moreover, our protocol uses mature seeds as the explant, which can easily be obtained in quantity throughout the year and kept

  8. Characterization of 140 Japanese and world rice collections cultivated in Nihonmatsu-city in Fukushima in terms of radiocesium activity concentrations in seed grains and straws to explore rice cultivars with low radiocesium accumulation

    International Nuclear Information System (INIS)

    Katsuhiro Kojima; Djedidi Salem

    2017-01-01

    We studied varietal difference in radiocesium accumulation by using Japanese and World rice collection for future development of low accumulation varieties. As a result, the radiocesium activity concentration varied by 12- and 22-fold in seed grains and straws, respectively. When we examined the seed grain to straw ratio of radiocesium activity concentration, paddy rice cultivars of Japonica sub-species showed a lower result than Indica and Javanica paddy rice cultivars. These observations suggest that the Japonica paddy rice cultivars may have the property of repressing radioactive cesium translocation to edible parts. (author)

  9. Induction of resistance to rice tungro virus disease in rice cultivar Pusa 2-21 through irradiation

    International Nuclear Information System (INIS)

    Mathur, S.C.; Rao, M.; Prakash, Jitendra

    1979-01-01

    The dry seeds of Pusa 2-21, a moderately resistant rice cultivar, were subjected to 10, 15 and 20 Krad (dose rate 12.3 Krad/min) radiation dosages of gamma rays to induce resistance against rice tungro virus disease. The height of M 1 seedling was significantly reduced in 15 and 20 Krad treatments. However, there was no effect of gamma irradiation on seed germination. A limited population of M 2 and M 3 generation was screened at the rate of 3 viruliferous leafhoppers/seedling using single plant caging technique. In M 2 generation 22.0, 17.6 and 25.0 percent seedlings exhibited green colour (symptomless) representing resistant reaction to the disease in 10, 15 and 20 Krad treatments, respectively. Out of 1470 seedlings in M 3 generation, 2.7 percent seedlings showing no symptoms of tungro could be isolated indicating the possibility of inducing higher degree of resistance than that of the parent to RTV through irradiation for the first time. (auth.)

  10. Cytoplasmic-genetic male sterility gene provides direct evidence for some hybrid rice recently evolving into weedy rice

    Science.gov (United States)

    Zhang, Jingxu; Lu, Zuomei; Dai, Weimin; Song, Xiaoling; Peng, Yufa; Valverde, Bernal E.; Qiang, Sheng

    2015-01-01

    Weedy rice infests paddy fields worldwide at an alarmingly increasing rate. There is substantial evidence indicating that many weedy rice forms originated from or are closely related to cultivated rice. There is suspicion that the outbreak of weedy rice in China may be related to widely grown hybrid rice due to its heterosis and the diversity of its progeny, but this notion remains unsupported by direct evidence. We screened weedy rice accessions by both genetic and molecular marker tests for the cytoplasmic male sterility (CMS) genes (Wild abortive, WA, and Boro type, BT) most widely used in the production of indica and japonica three-line hybrid rice as a diagnostic trait of direct parenthood. Sixteen weedy rice accessions of the 358 tested (4.5%) contained the CMS-WA gene; none contained the CMS-BT gene. These 16 accessions represent weedy rices recently evolved from maternal hybrid rice derivatives, given the primarily maternal inheritance of this trait. Our results provide key direct evidence that hybrid rice can be involved in the evolution of some weedy rice accessions, but is not a primary factor in the recent outbreak of weedy rice in China. PMID:26012494

  11. Cytoplasmic-genetic male sterility gene provides direct evidence for some hybrid rice recently evolving into weedy rice.

    Science.gov (United States)

    Zhang, Jingxu; Lu, Zuomei; Dai, Weimin; Song, Xiaoling; Peng, Yufa; Valverde, Bernal E; Qiang, Sheng

    2015-05-27

    Weedy rice infests paddy fields worldwide at an alarmingly increasing rate. There is substantial evidence indicating that many weedy rice forms originated from or are closely related to cultivated rice. There is suspicion that the outbreak of weedy rice in China may be related to widely grown hybrid rice due to its heterosis and the diversity of its progeny, but this notion remains unsupported by direct evidence. We screened weedy rice accessions by both genetic and molecular marker tests for the cytoplasmic male sterility (CMS) genes (Wild abortive, WA, and Boro type, BT) most widely used in the production of indica and japonica three-line hybrid rice as a diagnostic trait of direct parenthood. Sixteen weedy rice accessions of the 358 tested (4.5%) contained the CMS-WA gene; none contained the CMS-BT gene. These 16 accessions represent weedy rices recently evolved from maternal hybrid rice derivatives, given the primarily maternal inheritance of this trait. Our results provide key direct evidence that hybrid rice can be involved in the evolution of some weedy rice accessions, but is not a primary factor in the recent outbreak of weedy rice in China.

  12. Cultivar weed-competitiveness in aerobic rice : heritability, correlated traits, and the potential for indirect selection in weed-free environments

    NARCIS (Netherlands)

    Zhao, D.L.; Atlin, G.N.; Bastiaans, L.; Spiertz, J.H.J.

    2006-01-01

    Forty rice (Oryza sativa L.) cultivars and breeding lines used in the International Rice Research Institute (IRRI) upland rice breeding program were evaluated in adjacent weed-free and weedy trials in aerobic soil conditions during the wet seasons of 2001, 2002, and 2003. The objectives of this

  13. An improved Agrobacterium-mediated transformation of recalcitrant indica rice (Oryza sativa L.) cultivars.

    Science.gov (United States)

    Shri, Manju; Rai, Arti; Verma, Pankaj Kumar; Misra, Prashant; Dubey, Sonali; Kumar, Smita; Verma, Sikha; Gautam, Neelam; Tripathi, Rudra Deo; Trivedi, Prabodh Kumar; Chakrabarty, Debasis

    2013-04-01

    Agrobacterium-mediated transformation of indica rice varieties has been quite difficult as these are recalcitrant to in vitro responses. In the present study, we established a high-efficiency Agrobacterium tumefaciens-mediated transformation system of rice (Oryza sativa L. ssp. indica) cv. IR-64, Lalat, and IET-4786. Agrobacterium strain EHA-101 harboring binary vector pIG121-Hm, containing a gene encoding for β-glucuronidase (GUS) and hygromycin resistance, was used in the transformation experiments. Manipulation of different concentrations of acetosyringone, days of co-culture period, bacterial suspension of different optical densities (ODs), and the concentrations of L-cysteine in liquid followed by solid co-culture medium was done for establishing the protocol. Among the different co-culture periods, 5 days of co-culture with bacterial cells (OD600 nm = 0.5-0.8) promoted the highest frequency of transformation (83.04 %) in medium containing L-cysteine (400 mg l(-1)). Putative transformed plants were analyzed for the presence of a transgene through genomic PCR and GUS histochemical analyses. Our results also suggest that different cultural conditions and the addition of L-cysteine in the co-culture medium improve the Agrobacterium-mediated transformation frequencies from an average of 12.82 % to 33.33 % in different indica rice cultivars.

  14. Late nitrogen application enhances spikelet number in indica hybrid rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Wei Zhou

    Full Text Available ABSTRACT To increase rice yield potential, field experiments were conducted in farmers’ paddies in 2011 and 2012 to evaluate the effects of different nitrogen applications on the yield and panicle components of three typical indica hybrid rice varieties in Sichuan Province. The number of grains per panicle resulting from late nitrogen application (LA was 12 % greater than that obtained from traditional nitrogen application (TA; this increase was the main source of improvements in yield. The number of surviving and differentiated spikelets (NSS and NDiS resulting from LA was significantly higher than that measured under TA, especially for the Fyou498 cultivar, where the NSS and NDiS increased by 15 % and 14 %, respectively. Compared with TA, the number of degenerated secondary branches and the percentage of degenerated secondary branches (NDeSB and PDeSB were significantly reduced by 9 % and 11 %, respectively, by LA. This is the first study to demonstrate that an increase in NSS and a decrease in NDeSB lead to yield-improving effects attributable to LA. The grain yields of different varieties ranged from 9225.6 to 9408.7 kg ha−1, the PDeSB was as high as 31 %, and the number of surviving secondary branches (NSSB was significantly and positively correlated with NSS. These data indicate that the yield of indica hybrid rice has considerable potential for being improved, and increasing NSSB is key to increasing NSS and improving the grain yield. These improvements should be pursued so as to increase the yield of hybrid rice to ensure both food security and sustainable agricultural development.

  15. Improvement of rice starch by gamma irradiation

    International Nuclear Information System (INIS)

    Duan Zhiying; Wu Dianxing; Shen Shengquan; Han Juanying; Xia Yingwu

    2003-01-01

    Three types of rice cultivars, Indica, Japonica and hybrid rice, with similar intermediate apparent amylose content (AAC) as well as early Indica rice cultivars with different amounts of AAC were selected for studying the effects of gamma irradiation on starch viscosity, physico-chemical properties and starch granule structure. Four major parameters of RVA profile, peak viscosity (PKV), hot paste viscosity (HPV), cool paste viscosity (CPV), setback viscosity (SBV) and consistence viscosity (CSV) were considerably decreased with increasing dose levels. Gamma irradiation reduced the amylose contents in the cultivars with low AAC, intermediate AAC, and glutinous rice, but had no effects on the high AAC cultivar. No visible changes in alkali spreading value (ASV) were detected after irradiation, but the peak time (PKT) were reduced with the dose level. Gel consistency (GC) were significantly increased in the tested cultivars, especially in the high AAC Indica rice, suggesting that it is promising to use gamma irradiation to improve eating and cooking quality of rice

  16. Suscetibilidade de biótipos de arroz-vermelho e de cultivares de arroz irrigado ao herbicida imazethapyr Susceptibility of red rice biotypes and commercial rice cultivars to imazethapyr

    Directory of Open Access Journals (Sweden)

    S.H.B. Dornelles

    2010-01-01

    Full Text Available Para avaliar a suscetibilidade de biótipos de arroz-vermelho(Oryza sativa e cultivares comerciais de arroz ao herbicida imazethapyr, realizou-se um ensaio em casa de vegetação com cinco biótipos de arroz-vermelho (acessos Santa Maria 5, Pelotas 3, Rio Pardo 1, Manoel Viana 2 e Catuçaba 1, dois cultivares comerciais de arroz: Clearfield® (IRGA 422 CL e Puitá INTA CL e um cultivar convencional (IRGA 417. Utilizou-se a metodologia de curvas de dose-resposta proposta por Seefeldt et al. (1995. A metodologia de curvas de resposta foi gerada a partir dos parâmetros do modelo logístico e dos valores de I50. Os biótipos de arroz-vermelho e os cultivares foram submetidos a seis doses do herbicida imazethapyr (0; 33,12; 66,25; 132,5; 265,0; e 530,0 g i.a. ha-1. As plantas de arroz foram contadas e coletadas no 20º dia após a aplicação dos tratamentos. A análise do percentual de dano foi realizada através de avaliação visual da fitointoxicação (%, massa verde e massa seca das plantas. Analisando as curvas e os resultados da análise da variância, pode-se inferir que os cultivares Clearfield Irga 422 CL e Puitá INTA CL foram significativamente iguais ao biótipo de arroz-vermelho Catuçaba 1, resistindo a doses de imazethapyr superiores à recomendada em campo para o sistema Clearfield®. Os biótipos Manoel Viana 2, Santa Maria 5 e Pelotas 3 agruparam-se com o cultivar convencional IRGA 417, sendo suscetíveis à dose comercial do herbicida. O biótipo Rio Pardo 1 também é resistente ao herbicida imazethapyr, porém menos resistente que o biótipo Catuçaba 1.To evaluate the susceptibility of biotypes of red rice (Oryza sativa and commercial rice cultivars to the herbicide imazethapyr, a greenhouse assay was conducted with five red rice biotypes (accesses Santa Maria 5, Pelotas 3, Rio Pardo 1, 2 and Manoel Viana Catuçaba 1, two commercial rice cultivars: Clearfield ® (Irga CL 422 and CL Puit INTA, and a conventional cultivar (Irga

  17. Genetic Analysis of East Asian Grape Cultivars Suggests Hybridization with Wild Vitis.

    Science.gov (United States)

    Goto-Yamamoto, Nami; Sawler, Jason; Myles, Sean

    2015-01-01

    Koshu is a grape cultivar native to Japan and is one of the country's most important cultivars for wine making. Koshu and other oriental grape cultivars are widely believed to belong to the European domesticated grape species Vitis vinifera. To verify the domesticated origin of Koshu and four other cultivars widely grown in China and Japan, we genotyped 48 ancestry informative single nucleotide polymorphisms (SNPs) and estimated wild and domesticated ancestry proportions. Our principal components analysis (PCA) based ancestry estimation revealed that Koshu is 70% V. vinifera, and that the remaining 30% of its ancestry is most likely derived from wild East Asian Vitis species. Partial sequencing of chloroplast DNA suggests that Koshu's maternal line is derived from the Chinese wild species V. davidii or a closely related species. Our results suggest that many traditional East Asian grape cultivars such as Koshu were generated from hybridization events with wild grape species.

  18. Genetic Analysis of East Asian Grape Cultivars Suggests Hybridization with Wild Vitis.

    Directory of Open Access Journals (Sweden)

    Nami Goto-Yamamoto

    Full Text Available Koshu is a grape cultivar native to Japan and is one of the country's most important cultivars for wine making. Koshu and other oriental grape cultivars are widely believed to belong to the European domesticated grape species Vitis vinifera. To verify the domesticated origin of Koshu and four other cultivars widely grown in China and Japan, we genotyped 48 ancestry informative single nucleotide polymorphisms (SNPs and estimated wild and domesticated ancestry proportions. Our principal components analysis (PCA based ancestry estimation revealed that Koshu is 70% V. vinifera, and that the remaining 30% of its ancestry is most likely derived from wild East Asian Vitis species. Partial sequencing of chloroplast DNA suggests that Koshu's maternal line is derived from the Chinese wild species V. davidii or a closely related species. Our results suggest that many traditional East Asian grape cultivars such as Koshu were generated from hybridization events with wild grape species.

  19. Performance, Economics and Potential Impact of Perennial Rice PR23 Relative to Annual Rice Cultivars at Multiple Locations in Yunnan Province of China

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    Guangfu Huang

    2018-04-01

    Full Text Available Perennial grain crops hold the promise of stabilizing fragile lands, while contributing grain and grazing in mixed farming systems. Recently, perennial rice was reported to successfully survive, regrow, and yield across a diverse range of environments in Southern China and Laos, with perennial rice PR23 being identified as a prime candidate for release to farmers. This paper reports the evaluation of PR23 for release, by (1 comparing its survival, regrowth, performance, and adaptation with preferred annual rices across nine ecological regions in southern Yunnan Province of China; (2 examining the economic costs and benefits of perennial versus annual rice there; and (3 discussing the evidence for the release of PR23 as a broadly adapted and acceptable cultivar for farmers. Overall, the grain yield of PR23 was similar to those of the preferred annual rice cultivars RD23 and HXR7, but the economic analysis indicated substantial labour savings for farmers by growing the perennial instead of the annual. PR23 was comparable to the annuals in phenology, plant height, grain yield, and grain size, and was acceptable in grain and cooking quality. Farmers were keen to grow it because of reduced costs and especially savings in labour. PR23 is proposed for release to farmers because of its comparable grain yields to annual rices, its acceptable grain and milling quality, its cost and labour savings, and the likely benefits to soil stability and ecological sustainability, along with more flexible farming systems.

  20. Effects of Different Planting Times of Different Rice Cultivars on Control of the Striped Stem Borer (Chilo suppressalis (Lepidoptera: Pyralidae

    Directory of Open Access Journals (Sweden)

    T. Oskou

    2016-06-01

    Full Text Available Introduction: Rice (Oryza sativa L. is one of the world’s most important staple food crops. In Asia, it is the main item of the diet of 3.5 billion people. Rice stem borers are common insect pests in many rice growing countries. Striped stem borer (Chilo suppressalis Walker, belonging to Lepidoptera and family of Pyralidae is the most important rice pest in the Northern Iran. Stem borer larva damages rice stem and disturbs nutrient translocation from root to leaf. As the result, tillers in vegetative stage died, which is called dead heart. When larva infests generative stage, it causes empty panicle, which is called white head. Integrated pest management (IPM practices for controlling the stem borers in Iran have not been fully implemented because of limited control technologies which are available. Farmers often rely on heavily insecticide application, although many insecticide applications are not effective. Therefore, many physical and cultural practices have been suggested, including adjustment of planting time to escape the plant from heavy pest. Materials and Methods: The study was conducted in deputy of rice research institute in Amol, Mazandaran, Iran, during 2011-2012. The experiment was arranged in split plot design with planting time as main plot and cultivar as subplot and was replicated three times. Three planting times tested were the first planting time i.e. 15 days before farmers’ planting time, the second planting time (simultaneously with farmers’ planting time, and the third planting time (15days after farmers’ planting time. Six rice cultivars tested, representing three types of rice cultivar, Tarom and Kohsar (early maturity cultivars, Shirodi and Fajr (medium maturity cultivars, Neda and Nemat (late maturity cultivar. Rice seedlings were transplanted at 25 cm planting distance in a 3 m x 9 m plot size. Weeding and fertilization were done as recommended. No insecticide was applied. Dead hearts and white heads were

  1. Competitividade relativa entre cultivares de arroz irrigado e biótipo de capim-Arroz (Echinochloa spp. Relative competitivity between flooded rice cultivars and Echinochloa spp.

    Directory of Open Access Journals (Sweden)

    D. Agostinetto

    2008-01-01

    Full Text Available As espécies pertencentes ao gênero Echinochloa se destacam como principais infestantes das lavouras de arroz irrigado do Rio Grande do Sul, causando dano econômico à cultura devido à elevada competitividade pelos recursos do ambiente. O trabalho teve por objetivo comparar as habilidades competitivas relativas entre dois cultivares de arroz e um biótipo de capim-arroz. Para isso, foram realizados experimentos em casa de vegetação na estação de crescimento 2006/07, em delineamento experimental inteiramente casualizado, com quatro repetições. Os tratamentos foram arranjados em série substitutiva, com cinco proporções de plantas de arroz e do competidor (100:0; 75:25; 50:50; 25:75; e 0:100, mantendo a população constante de 24 plantas vaso-1 das espécies associadas. O arroz foi representado pelos cultivares IRGA 417 ou BR-IRGA 410, e o competidor, pelo biótipo de capim-arroz. A análise da competitividade foi efetuada por meio de diagramas aplicados a experimentos substitutivos e através de índices de competitividade relativa. As variáveis estudadas foram área foliar e massa seca aérea das plantas. Os resultados mostram que houve competição entre os cultivares de arroz IRGA 417 ou BR-IRGA 410 com o capim-arroz, independentemente da proporção de plantas na associação, com redução na área foliar e massa seca da parte aérea dos competidores. O capim-arroz apresenta menor perda de produtividade relativa, reduz as variáveis morfológicas do arroz e demonstra possuir superioridade competitiva, comparativamente aos cultivares de arroz.The Echinochloa species are among the most important weeds in flooded rice fields of Rio Grande do Sul, causing economic losses to the culture, due to its high competivity for environmental resources. The objective of this study was to compare the relative competitive abilities between two rice cultivars and an Echinochloa spp. biotype. Greenhouse experiments were conducted in 2006

  2. YIELD STABILITY OF NEW HYBRID RICE ACROSS LOCATIONS

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    Satoto

    2016-02-01

    Full Text Available The adaptation of hybrid rice varieties mostly are in specific location and season, but there are some of the varieties have a wide adaptation then adopted by the farmer in the large area. Replicated yield trials were conducted to study the stability of hybrid rice yield and identify the best location to optimize their yield per ha. The trials were conducted in three location such as Sukamandi, Salatiga and Malang during two seasons in 2011. Data across location and season were analazed by using AMMI and Eberhart Russel methods. The AMMI analysis showed that the IR79156A/PK88 was adaptable to favorable environments but unstable. This hybrid is always performing well and produce the higher yield compare to check variety. Some of other hybrids were good only in specific location, i.e. IR62829A/BP2280-1E-12-22 and IR58029A/BP2280-1E-12-22. Those hybrids produced higher yield in Salatiga and Malang, respectively. Seem to AMMI analysis, the result of Eberhart and Russell method also showed that IR79156A/PK81 was the best hybrid with regression slope (b around 1 with the yield average higher than average of all hybrids. It indicated that this hybrid has a wide adaptation and probably can be cultivated in the wider ecosystem.

  3. Seasonal CH4 and N2O emissions and plant growth characteristics of several cultivars in direct seeded rice systems

    Science.gov (United States)

    Simmonds, M.; Anders, M. M.; Adviento-Borbe, M. A.; Van Kessel, C.; McClung, A.; Linquist, B.

    2014-12-01

    Understanding cultivar effects on field greenhouse gas (GHG) emissions in rice (Oryza sativa L.) systems is needed to improve the accuracy of predictive models used for estimating GHG emissions, and to determine to what extent choice of cultivar may have on GHG mitigation. We compared CH4 and N2O emissions, global warming potential (GWP = N2O + CH4), yield-scaled GWP (GWPY = GWP Mg-1 grain), and plant growth characteristics of 8 cultivars within 4 study sites in California and Arkansas. Seasonal CH4 emissions differed between cultivars by a factor of 2.1 and 1.3 at one California and one Arkansas site, respectively. Nitrous oxide emissions were negligible, comprised food security.

  4. Metabolite profiles of rice cultivars containing bacterial blight-resistant genes are distinctive from susceptible rice

    Institute of Scientific and Technical Information of China (English)

    Jiao Wu; Haichuan Yu; Haofu Dai; Wenli Mei; Xin Huang; Shuifang Zhu; Ming Peng

    2012-01-01

    The metabolic changes of bacterial blight-resistant line C418/Xa23 generated by molecular marker-assisted selection (n =12),transgenic variety C418-Xa21 generated by using the Agrobacterium-mediated system (n =12),and progenitor cultivar C418 (n =12) were monitored using gas chromatography/mass spectrometry.The validation,discrimination,and establishment of correlative relationships between metabolite signals were performed by cluster analysis,principal component analysis,and partial least squares-discriminant analysis.Significant and unintended changes were observed in 154 components in C418/Xa23 and 48 components in C418-Xa21 compared with C418 (P < 0.05,Fold change > 2.0).The most significant decreases detected (P< 0.001) in both C418/Xa23 and C418-Xa21 were in three amino acids: glycine,tyrosine,and alanine,and four identified metabolites: malic acid,ferulic acid,succinic acid,and glycerol.Linoleic acid was increased specifically in C418/Xa23 which was derived from traditional breeding.This line,possessing a distinctive metabolite profile as a positive control,shows more differences vs.the parental than the transgenic line.Only succinic acid that falls outside the boundaries of natural variability between the two non-transgenic varieties C418 and C418/Xa23 should be further investigated with respect to safety or nutritional impact.

  5. The cadmium and lead content of the grain produced by leading Chinese rice cultivars.

    Science.gov (United States)

    Xie, L H; Tang, S Q; Wei, X J; Shao, G N; Jiao, G A; Sheng, Z H; Luo, J; Hu, P S

    2017-02-15

    The cadmium (Cd) and lead (Pb) content in both white and wholemeal flour milled from 110 leading rice cultivars was assessed. The white flour Cd content ranged from <0.0025 to 0.2530mg/kg (geometric mean (GM)=0.0150mg/kg), while its Pb content ranged from <0.0250 to 0.3830mg/kg (GM=0.0210mg/kg). The indica types took up higher amounts of Cd and Pb than did the japonica types. Although the heavy metal content of wholemeal flour tended to higher than that of white flour, nevertheless 84.5% (Cd) and 95.4% (Pb) of the entries were compliant with the national maximum allowable concentration of 0.2000mg/kg of each contaminant. An analysis of the Cd content in the white flour of three indica type cultivars grown in two consecutive years at two locations indicated that Cd content may be significantly affected by the conditions prevailing in the growing season. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Sensitivity of promising cherry hybrids and new cultivars to economically important fungal diseases

    Directory of Open Access Journals (Sweden)

    K. Vasileva

    2016-09-01

    Full Text Available Abstract. As a result of years of developing the breeding programme for creating novel sweet cherry cultivars in the Fruit Growing Institute (FGI, Plovdiv, a reach hybrid fund from first and second hybrid generation is created. Of the selected and propagated hybrids at a more advanced stage of testing are 11 hybrids along with three new cultivars of the FGI Plovdiv ('Kossara', 'Rosalina' and 'Trakiiska hrushtyalka' grafted on three rootstocks were tested for sensitivity to causers of economically important fungal diseases in sweet cherry - cherry leaf spot (Blumeriella jaapii (Rehm Arx, shothole blight (Stigmina carpophila (Lev. Ellis and brown rot (Monilinia fructigena (G. Wint Honey. The degree of infestation under field conditions is reported by determining the index of attack on leaves and fruit, using the formula of McKinney. As the most sensitive elites are outlined elite El.17-31 (to cherry leaf spot and elite El.17-136 (to shothole blight. The cultivars 'Kossara' and 'Trakiiska hrushtyalka' exhibit an average resistance to the three diseases, as the values for the index of infestation are lower or similar to those of standard cultivars 'Van' and 'Bing', while 'Rosalina' demonstrated sensitivity to shothole blight and brown rot. Interesting is the elite El.17- 37 demonstrating the least infestation of Blumeriella jaapii - 7.33% and Monilinia fructigena - 6.67%. The same has a set of valuable qualities as late maturing date and very large fruits with excellent sensory profile, making it a potential candidate cultivar.

  7. Isolation and characterization of plant growth promoting endophytic diazotrophic bacteria from Korean rice cultivars.

    Science.gov (United States)

    Ji, Sang Hye; Gururani, Mayank Anand; Chun, Se-Chul

    2014-01-20

    We have isolated 576 endophytic bacteria from the leaves, stems, and roots of 10 rice cultivars and identified 12 of them as diazotrophic bacteria using a specific primer set of nif gene. Through 16S rDNA sequence analysis, nifH genes were confirmed in the two species of Penibacillus, three species of Microbacterium, three Bacillus species, and four species of Klebsiella. Rice seeds treated with these plant growth-promoting bacteria (PGPB) showed improved plant growth, increased height and dry weight and antagonistic effects against fungal pathogens. In addition, auxin and siderophore producing ability, and phosphate solubilizing activity were studied for the possible mechanisms of plant growth promotion. Among 12 isolates tested, 10 strains have shown higher auxin producing activity, 6 isolates were confirmed as strains with high siderophore producing activity while 4 isolates turned out to have high phosphate-solubilizing activity. These results strongly suggest that the endophytic diazotrophic bacteria characterized in this study could be successfully used to promote plant growth and inducing fungal resistance in plants. Copyright © 2013 Elsevier GmbH. All rights reserved.

  8. Influence and interaction of iron and cadmium on photosynthesis and antioxidative enzymes in two rice cultivars.

    Science.gov (United States)

    Liu, Houjun; Zhang, Chengxin; Wang, Junmei; Zhou, Chongjun; Feng, Huan; Mahajan, Manoj D; Han, Xiaori

    2017-03-01

    In this study, a soil pot experiment was conducted to investigate the changes in photosynthesis and antioxidative enzymes in two rice varieties (Shendao 6 and Shennong 265) supplied with iron (Fe), cadmium (Cd), and Fe and Cd together. The concentrations of Fe and Cd in the soil were 0, 1.0 g Fe·kg -1 and 0, 2.0 mg Cd·kg -1 , respectively. Photosynthetic indices and antioxidative enzyme activities were recorded at different rice growth stages. At the early stage, Cd showed a transient stimulatory effect on the photosynthetic rate of Shennong 265. For Shendao 6, however, Cd showed a transient stimulatory effect on photosynthetic rate, intercellular CO 2 concentration, stomatal conductance and transpiration efficiency. In addition, the results show that Cd can also enhance the superoxide dismutase (SOD) and peroxidase (POD) activities, but reduce the malondialdehyde (MDA) and soluble protein contents in the two rice cultivars. Subsequently, Cd starts to inhibit photosynthesis and SOD activity until the ripening stage, causing the lowest photosynthetic rate and SOD activity at this stage. In contrast, Fe alleviates the Cd-induced changes at earlier or later growth stage. Notably at the later growth stage, the results show that the interaction between Fe and Cd increases the SOD and catalase (CAT) activities, while decreasing the lipid peroxidation and promoting photosynthesis. As a result, it ultimately increases the biomass. The results from this study suggest that Fe (as Fe fertilizer) is a promising alternative for agricultural use to enhance the plant development and, simultaneously, to reduce Cd toxicity in extensively polluted soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Use of seed protein polymorphism for discrimination of improvement level and geographic origin of upland rice cultivars

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    Ricardo Montalván

    1998-12-01

    Full Text Available Grain proteins from 58 Brazilian and nine Japanese upland rice cultivars (Oryza sativa L. were electrophoretically separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. Densitometric scanning of the electrophoretic profiles permitted the estimation of the relative concentration of 16 protein fractions, which were used as variables for the calculation of Fisher's canonical discriminating functions. Significant differences between mean values of protein fractions were useful in distinguishing Brazilian and Japanese cultivars, as well as improved and non-improved Brazilian rice cultivars in scattered plots. Electrophoretically detectable protein polymorphism in rice grain can indicate geographic origin as well as breeding improvement level of a cultivar. Improved cultivars were those released by plant breeding institutes.Proteínas de grão de 58 genótipos de arroz brasileiro e nove japoneses foram separadas por meio de eletroforese (SDS-PAGE. A observação densitométrica dos perfis eletroforéticos permitiu avaliar as concentrações relativas de 16 frações protéicas que foram usadas como variáveis para a estimativa de funções discriminantes de Fisher. Diferenças significantes foram encontradas entre as frações protéicas dos grupos brasileiros e japoneses, assim como entre os genótipos melhorados e não melhorados. O polimorfismo protéico detectável eletroforetica-mente nos grãos de arroz pode indicar a origem geográfica e o nível de melhoramento dos cultivares.

  10. Preliminary report on the rice blast resistance of space-induced mutants derived from rice cultivar 'Taihang-68'

    International Nuclear Information System (INIS)

    Zhang Jingxin; Sun Dayuan; Wang Hui; Liu Yongzhu; Guo Tao; Chen Zhiqiang; Yang Qiyun; Zhu Xiaoyuan

    2012-01-01

    To screen the blast resistance mutants, the resistance of SP 1 progenies derived from rice variety Taihang-68 were evaluated after satellite flight by representative blast isolate GD0193 which had a broad pathogenic spectra, and then primary genetic analysis of resistant mutants and mapping of resistance gene, as well as resistance spectra at seedling and neck blast resistance at maturity were performed. The results showed that space-mutation was effective method to change the blast resistance of Taihang-68. The screened resistant mutants TH1 and TH2 showed that resistance to isolate GD0193 no disjunction and separation respectively, and the resistance separation ratio of TH2 indicated that its resistance was controlled by one pair of major genes, which was preliminary mapped on the long arm of chromosome 11. In blast resistance spectra and neck blast resistance, TH1 and TH2 were both enhanced remarkable compared with the wild-type at seedling and maturity, and their resistance could be inherited, the blast resistance of these two mutants were also increased comparing with several main cultivars in South China. (authors)

  11. Induction of bacterial blight resistance in elite Indian rice cultivars using gamma-rays and ethyl methanesulfonate

    International Nuclear Information System (INIS)

    Agrawal, P.K.; Gosal, S.S.; Sidhu, G.S.

    2001-01-01

    Rice is the most important cereal crop in the world feeding more than 50 percent of the human population. During the last 30 years, induced mutation breeding has played a significant role in rice breeding programmes. Rice mutants with higher yield, greater tolerance to diseases and pests and other agronomic qualities have been released for commercial cultivation in many countries. Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae is the second important disease in Southeast Asia. In the Basmati field sometime the yield loss is up to 100%. Moreover, there is no resistance source available. In Basmati rice, which is known for its quality and aroma. Induction of bacterial blight resistance in Basmati will help in developing high yielding Basmati type cultivars without compromising the quality

  12. Mutant-inducing effect of γ-ray irradiation for hybrid rice F1 derived from cross of black glutinous rice x wild rice

    International Nuclear Information System (INIS)

    Mao Dezhi; Tang Yilan

    1998-01-01

    The hybrid rice F 1 plant derived from the back crossing of glutinous rice x wild rice was irradiated with γ-ray. The result of investigation to the induced mutant showed that through the selection and backcross, a black glutinous rice strain with the short stem, cold tolerance and high yield was developed. The analysis of the ability of heredity variance showed that the selection was effective for the husk colour, black glutinous and black Indica rice, but ineffective for the white Indica rice and seed setting

  13. Cultivars

    Directory of Open Access Journals (Sweden)

    Oleg Blum

    2011-01-01

    Full Text Available Some modern agrochemicals with antioxidant potential were tested for their protective effect against ozone injury using clover and tobacco ozone-sensitive cultivars as model plants subjected to ambient ozone at two sites (Kyiv city in Ukraine and Szarów village in Poland. All used agrochemicals showed partial protective effects against ozone injury on clover and tobacco. Conducted studies confirmed the effectiveness of modern fungicides belonging to strobilurin group as protectants of sensitive crops against ozone damage. The effectiveness of new growth regulators “Emistym C” and “Agrostymulin” was showed for the first time. Out of the studied agrochemicals, fungicide “Strobi” and natural growth regulator “Emistym C” demonstrated the best protective effects. These agrochemicals present promise for further studies of their possible utilization for enhancement of ozone tolerance of sensitive crops.

  14. Enzyme expression in indica and japonica rice cultivars under saline stress=Expressão de enzimas em cultivares de arroz indica e japonica sob estresse salino

    Directory of Open Access Journals (Sweden)

    Cristina Rodrigues Mendes

    2012-10-01

    Full Text Available The southern State of Rio Grande do Sul (RS is the main rice producer in Brazil with a 60% participation of the national production and 86% participation of the region. Rice culture irrigation system is done by flooding, which leads to soil salinization, a major environmental constraint to production since it alters the plants’ metabolism exposed to this type of stress. The indica cultivar, widely used in RS, has a higher sensitivity to salinity when compared to that of the japonica cultivar in other physiological aspects. Current research analyzes enzymes expression involved in salt-subjected indica and japonica rice cultivars’ respiration. Oryza sativa L. spp. japonica S.Kato (BRS Bojuru, IAS 12-9 Formosa and Goyakuman and Oryza sativa L. spp. indica S. Kato (BRS Taim-7, BRS Atalanta and BRS Querencia were the cultivars employed. Seedlings were transferred to 15 L basins containing 50% Hoagland nutrient solution increased by 0, 25, 50, 75 and 100 mM NaCl, and collected at 14, 28 and 42 days after transfer (DAT. Plant tissues were macerated and placed in eppendorf tubes with Scandálios extractor solution. Electrophoresis was performed in 7% of the polyacrylamide gels in vertical vats. Bands were revealed for the following enzymes systems: esterase, alcohol dehydrogenase, phosphoglucoisomerase, malate dehydrogenase, malic enzyme and alpha amylase. The enzymes expression was greater in subspecies japonica, with more intense bands in proportion to salinity increase. Results show that enzyme systems are involved in the salinity defense mechanisms in O. sativa spp. japonica cultivar.O Estado do Rio Grande do Sul (RS destaca-se como principal produtor de arroz, participando com 60% da produção nacional e 86% da regional. O sistema de irrigação da cultura é por inundação, que induz o solo à salinização, um dos maiores limitadores ambientais à produção, alterando o metabolismo da plantas expostas a este tipo de estresse. As cultivares

  15. DNA fingerprinting of Kentucky bluegrass cultivars and hybrids

    Science.gov (United States)

    As a high polyploidy, apomictic, self-incompatible, perennial grass, Kentucky bluegrass has such complex genetic architecture that conducting standard Mendelian genetic selection is currently impossible. One large hurdle is the inability to differentiate true hybrids from other apomictic progenies....

  16. ‘Norine’, a cinnamon-linalool hybrid cultivar of basil

    Directory of Open Access Journals (Sweden)

    Arie Fitzgerald Blank

    2015-12-01

    Full Text Available 'Norine’ is a hybrid cultivar of basil, adapted to the Northeastern Brazil, which is derived from the cultivars ‘Cinnamon’ and ‘Maria Bonita’. It has essential oil content of 2.91% and yield of 2.37 mL plant-1. The main chemical compounds of the essential oil are (E-methyl cinnamate (41.93 % and linalool (34.92 %. ‘Norine’ is characterized by presenting upright growth habit, rounded crown, mean height of 55 cm, mean crown diameter of 59 cm, mean leaf length of 8.4 cm, and mean leaf width of 4.5 cm.

  17. Mapping and pyramiding of two major genes for resistance to the brown planthopper (Nilaparvata lugens [St?l]) in the rice cultivar ADR52

    OpenAIRE

    Myint, Khin Khin Marlar; Fujita, Daisuke; Matsumura, Masaya; Sonoda, Tomohiro; Yoshimura, Atsushi; Yasui, Hideshi

    2011-01-01

    The brown planthopper (BPH), Nilaparvata lugens (St?l), is one of the most serious and destructive pests of rice, and can be found throughout the rice-growing areas of Asia. To date, more than 24 major BPH-resistance genes have been reported in several Oryza sativa ssp. indica cultivars and wild relatives. Here, we report the genetic basis of the high level of BPH resistance derived from an Indian rice cultivar, ADR52, which was previously identified as resistant to the whitebacked planthoppe...

  18. Regulation of glutamine synthetase isoforms in two differentially drought-tolerant rice (Oryza sativa L.) cultivars under water deficit conditions.

    Science.gov (United States)

    Singh, Kamal Krishna; Ghosh, Shilpi

    2013-02-01

    KEY MESSAGE : The regulation of GS isoforms by WD was organ specific. Two GS isoforms i.e. OsGS1;1 and OsGS2 were differentially regulated in IR-64 (drought-sensitive) and Khitish (drought-tolerant) cultivars of rice. Water deficit (WD) has adverse effect on rice (Oryza sativa L.) and acclimation requires essential reactions of primary metabolism to continue. Rice plants utilize ammonium as major nitrogen source, which is assimilated into glutamine by the reaction of Glutamine synthetase (GS, EC 6.3.1.2). Rice plants possess one gene (OsGS2) for chloroplastic GS2 and three genes (OsGS1;1, OsGS1;2 and OsGS1;3) for cytosolic GS1. Here, we report the effect of WD on regulation of GS isoforms in drought-sensitive (cv. IR-64) and drought-tolerant (cv. Khitish) rice cultivars. Under WD, total GS activity in root and leaf decreased significantly in IR-64 seedlings in comparison to Khitish seedlings. The reduced GS activity in IR-64 leaf was mainly due to decrease in GS2 activity, which correlated with decrease in corresponding transcript and polypeptide contents. GS1 transcript and polypeptide accumulated in leaf during WD, however, GS1 activity was maintained at a constant level. Total GS activity in stem of both the varieties was insensitive to WD. Among GS1 genes, OsGS1;1 expression was differently regulated by WD in the two rice varieties. Its transcript accumulated more abundantly in IR-64 leaf than in Khitish leaf. Following WD, OsGS1;1 mRNA level in stem and root tissues declined in IR-64 and enhanced in Khitish. A steady OsGS1;2 expression patterns were noted in leaf, stem and root of both the cultivars. Results suggest that OsGS2 and OsGS1;1 expression may contribute to drought tolerance of Khitish cultivar under WD conditions.

  19. Selection of drought tolerant and high water use efficient rice cultivars through /sup 13/C isotope discrimination technique

    International Nuclear Information System (INIS)

    Akhtar, J.; Sabir, S.A.; Ashraf, M.Y.; Monneveux, P.; Serraj, R.

    2010-01-01

    Carbon isotope discrimination ('A') has been suggested as an indirect tool for selecting plants having higher water use efficiency (WUE) and yield potential. Enhancing WUE is an important breeding objective as water scarcity is increasing with every passing day. This study was undertaken to assess the genotypic variation and relationship between leaf, straw, grain 'A', grain yield and WUE in eight aromatic rice cultivars grown in lysimeters under three water regimes, in absence of drainage and runoff. Highly significant positive correlations were found between aboveground biomass and WUEB, and grain yield and WUEG, due to the low variation in water consumed by different cultivars. Leaf, straw and grain A showed a consistent variation across treatments and cultivars. Under water stress conditions, both leaf and straw 'A' were positively correlated to grain yield and WUEG. In all the water treatments, WUEG was positively correlated to harvest index and negatively to plant height. All the mutants from Basmati 385 had significantly higher 'A' values as compared to the mutants from Basmati 370. It was concluded that the new cultivar, Basmati 385, represents a better genetic source for 'A' improvement than the old cultivar, Basmati 370. (author)

  20. Examination of two lowland rice cultivars reveals that gibberellin-dependent early response to submergence is not necessarily mediated by ethylene.

    Science.gov (United States)

    Dubois, Vincent; Moritz, Thomas; García-Martínez, José L

    2011-01-01

    Using two lowland rice (Oryza sativa L.) cultivars we found that in both cases submerged-induced elongation early after germination depends on gibberellins (GAs). Submergence increases the content of the active GA 1 by enhancing the expression of GA biosynthesis genes, thus facilitating the seedlings to escape from the water and preventing asphyxiation. However, the two cultivars differ in their response to ethylene. The cultivar Senia (short), by contrast to cultivar Bomba (tall), does not elongate after ethylene application, and submerged-induced elongation is not negated by an inhibitor of ethylene perception. Also, while ethylene emanation in Senia is not altered by submergence, Bomba seedlings emanate more ethylene upon de-submergence, associated with enhanced expression of the ethylene biosynthesis gene OsACS5. The cultivar Senia thus allows the possibility of clarifying the role of ethylene and other factors as triggers of GA biosynthesis enhancement in rice seedlings under submergence.

  1. Ability of Arkansas LaKast and LaKast Hybrid Rice Bran to Reduce Salmonella Typhimurium in Chicken Cecal Incubations and Effects on Cecal Microbiota

    Directory of Open Access Journals (Sweden)

    Sun Ae Kim

    2018-02-01

    Full Text Available The objective of the present study was to evaluate the prebiotic ability of Arkansas (AR LaKast rice bran cultivars as a feed supplement to reduce Salmonella Typhimurium and other gut microbiota. An in vitro mixed anaerobic culture system was used to simulate conditions in the chicken ceca. Anaerobic cultures contained feed, cecal contents collected from 2, 4, and 6 weeks of chicken broilers, and with/without AR rice bran (pureline and hybrid. After 24 h pre-incubation, S. Typhimurium was inoculated into the anaerobic cultures and surviving S. Typhimurium were enumerated during anaerobic incubation up to 48 h. Samples were also collected after 0, 6, 12, 24, 48 h incubation for microbiome analysis with an Illumina MiSeq platform to investigate the changes in bacterial composition. Both pure and hybrid LaKast rice exhibited significant inhibitory effects in all experiments using 2, 4, and 6 weeks ceca but greater bactericidal effects by LaKast rice were observed at 6 weeks compared to 2- and 4-week ceca samples. For samples containing 6-week chicken ceca, the pureline and hybrid rice bran resulted in no viable S. Typhimurium and 6.58 log CFU/ml reduction after 48 h, respectively. Adding rice bran also led to changes in the cecal microbiota. LaKast rice bran resulted in more diverse bacterial population than control groups without any rice bran. The lowest abundance of Proteobacteria (at phylum level and Enterobacteriaceae (at family and genus level was exhibited in LaKast pure treated groups followed by LaKast hybrid and control. This may be attributed to a significant reduction of S. Typhimurium of the Enterobacteriaceae family and Proteobacteria phylum. This study suggests the beneficial functionality of LaKast rice brans as biological supplements in feed. The use of rice bran is favorable for both the consumer and the rice industry because of the perception of rice bran as a naturally occurring substance. As an abundant by-product of rice

  2. The absorption ability for carbohydrate between vigorous and weak spikelets in hybrid rice and its restorers

    International Nuclear Information System (INIS)

    Wang Xi; Tao Longxing; Tian Shulan; Huang Xiaolin; Yu Meiyu

    2000-01-01

    Some hybrid rice combinations and their restorers, II you2070 (indica/Indica) and its restorer2070, Shuangyou23 (Japonica/Japonica) with its restorer 91-23, sub-species hybrid rice Xieyou 413 (Indica/Japonica) with its restorer Zhong 413, were selected as rice material and planted in pot and field to study the differences of absorption ability for labelled carbohydrate between vigorous and weak spikelets, and to demonstrate the phenomenon of 'inter-grain apical dominance' in rice. It was shown that the absorbing rate of hybrid rice and it restorer for store material and for photo-material was 50% and 80% respectively, and the absorbing rate of hybrid rice was a litter higher than that of its restorer. However, there was a big difference between vigorous spikelets and weak spikelets in the absorbing ability for carbohydrate. The absorbing amount of vigorous spikelets was 10 times higher than that of the weak spikelets, especially in hybrid rice combinations. It was also observed that the 'inter-grain apical dominance' in hybrid rice was stronger than its restorer, which might be one of the main reasons for low seed setting in hybrid rice combination

  3. Impact of rice cultivar and organ on elemental composition of phytoliths and the release of bio-available silicon

    Directory of Open Access Journals (Sweden)

    Zimin eLi

    2014-10-01

    Full Text Available The continental bio-cycling of silicon (Si plays a key role in global Si cycle and as such partly controls global carbon (C budget through nutrition of marine and terrestrial biota, accumulation of phytolith-occluded organic carbon (PhytOC and weathering of silicate minerals. Despite the key role of elemental composition of phytoliths on their solubility in soils, the impact of plant cultivar and organ on the elemental composition of phytoliths in Si high-accumulator plants, such as rice (Oryza sativa is not yet fully understood. Here we show that rice cultivar significantly impacts the elemental composition of phytoliths (Si, Al, Fe and C in different organs of the shoot system (grains, sheath, leaf and stem. The amount of occluded OC within phytoliths is affected by contents of Si, Al and Fe in plants, while independent of the element composition of phytoliths. Our data document, for different cultivars, higher bio-available Si release from phytoliths of leaves and sheaths, which are characterized by higher enrichment with Al and Fe (i.e., lower Si/Al and Si/Fe ratios, compared to grains and stems. We indicate that phytolith solubility in soils may be controlled by rice cultivar and type of organs. Our results highlight that the role of the morphology, the hydration rate and the chemical composition in the solubility of phytoliths and the kinetic release of Si in soil solution needs to be studied further. This is central to a better understanding of the impact of soil amendment with different plant organs and cultivars on soil OC stock and on the delivery of dissolved Si as we show that sheath and leaf rice organs are both characterized by higher content of OC occluded in phytolith and higher phytolith solubility compared to grains and stems. Our study shows the importance of studying the impact of the agro-management on the evolution of sinks and sources of Si and C in soils used for Si-high accumulator plants.

  4. Assessing the impact of ambient ozone on growth and yield of a rice (Oryza sativa L.) and a wheat (Triticum aestivum L.) cultivar grown in the Yangtze Delta, China, using three rates of application of ethylenediurea (EDU)

    International Nuclear Information System (INIS)

    Wang Xiaoke; Zheng Qiwei; Yao Fangfang; Chen Zhan; Feng Zhaozhong; Manning, W.J.

    2007-01-01

    Foliar applications of ethylenediurea (abbreviated as EDU) were made at 0, 150, 300 or 450 ppm to field-grown rice and wheat in the Yangtze Delta in China. Rice and wheat responded differently to ambient ozone and EDU applications. For wheat, some growth characteristics, such as yield, seed number per plant, seed set rate and harvest index, increased significantly at 300 ppm EDU treatment, while for rice no parameters measured were statistically different regarding EDU application. The reason may be that the wheat cultivar used may be more sensitive to ozone than the rice cultivar. EDU was effective in demonstrating ozone effects on the wheat cultivar, but not on the rice cultivar. Cultivar sensitivity might be an important consideration when assessing the effects of ambient ozone on plants. - Cultivar sensitivity should be considered when using protective chemical to assess the effects of ambient ozone on plants

  5. Soil Texture and Cultivar Effects on Rice (Oryza sativa, L. Grain Yield, Yield Components and Water Productivity in Three Water Regimes.

    Directory of Open Access Journals (Sweden)

    Fugen Dou

    Full Text Available The objective of this study was to determine the effects of water regime/soil condition (continuous flooding, saturated, and aerobic, cultivar ('Cocodrie' and 'Rondo', and soil texture (clay and sandy loam on rice grain yield, yield components and water productivity using a greenhouse trial. Rice grain yield was significantly affected by soil texture and the interaction between water regime and cultivar. Significantly higher yield was obtained in continuous flooding than in aerobic and saturated soil conditions but the latter treatments were comparable to each other. For Rondo, its grain yield has decreased with soil water regimes in the order of continuous flooding, saturated and aerobic treatments. The rice grain yield in clay soil was 46% higher than in sandy loam soil averaged across cultivar and water regime. Compared to aerobic condition, saturated and continuous flooding treatments had greater panicle numbers. In addition, panicle number in clay soil was 25% higher than in sandy loam soil. The spikelet number of Cocodrie was 29% greater than that of Rondo, indicating that rice cultivar had greater effect on spikelet number than soil type and water management. Water productivity was significantly affected by the interaction of water regime and cultivar. Compared to sandy loam soil, clay soil was 25% higher in water productivity. Our results indicated that cultivar selection and soil texture are important factors in deciding what water management option to practice.

  6. Cadmium accumulation characteristics of low-cadmium rice (Oryza sativa L.) line and F1 hybrids grown in cadmium-contaminated soils.

    Science.gov (United States)

    Li, Kun; Yu, Haiying; Li, Tingxuan; Chen, Guangdeng; Huang, Fu

    2017-07-01

    Cadmium (Cd) pollution has threatened severely to food safety and human health. A pot experiment and a field experiment were conducted to investigate the difference of Cd accumulation between rice (Oryza sativa L.) lines and F 1 hybrids in Cd-contaminated soils. The adverse effect on biomass of rice lines was greater than that of F 1 hybrids under Cd treatments in the pot experiment. The variations of Cd concentration among rice cultivars in different organs were smaller in stem and leaf, but larger in root and ear. Average proportion of Cd in root of F 1 hybrids was 1.39, 1.39, and 1.16 times higher than those of rice lines at the treatment of 1, 2, and 4 mg Cd kg -1 soil, respectively. Cd concentrations in ear of F 1 hybrids were significantly lower than rice lines with the reduction from 29.24 to 50.59%. Cd concentrations in brown rice of all F 1 hybrids were less than 0.2 mg kg -1 at 1 mg Cd kg -1 soil, in which Lu98A/YaHui2816, 5406A/YaHui2816, and C268A/YaHui2816 could be screened out as cadmium-safe cultivars (CSCs) for being safe even at 2 mg Cd kg -1 soil. C268A/YaHui2816 showed the lowest Cd concentration in root among F 1 hybrids, while Lu98A/YaHui2816 and 5406A/YaHui2816 showed lower capability of Cd translocation from root to shoot under Cd exposure, which eventually caused the lower Cd accumulation in brown rice. The lower level of Cd translocation contributed to reducing the accumulation of Cd in brown rice had been validated by the field experiment. Thus, Lu98A/YaHui2816, 5406A/YaHui2816, and C268A/YaHui2816 could be considered as potential CSCs to cultivate in Cd-contaminated soils (<2 mg Cd kg -1 soil).

  7. Release of a new lodging-resistant mutant cultivar produced by gamma-rays in glutinous rice

    International Nuclear Information System (INIS)

    Yamaguchi, Hikoyuki; Igarashi, Isao; Sato, Takeshi

    2001-01-01

    To obtain short culm mutants with lodging resistance, while retaining the other desirable traits, such as an excellent quality of the original variety, dry seeds of a glutinous rice cultivar Mezuru were exposed to gamma-rays. In M3, thirty plants were selected from 4020 plants, based on the short culm length. From the results of the subsequent yield and adaptability tests, a promising mutant line was called by the name of Sakata-Mezuru as a new cultivar in 1996. This mutant variety was mainly characterized by shortening of each internode, especially the lowest internode, and at harvest it was more adaptable to mechanical work due to the lodging resistance than its parent. It was demonstrated that the grain quality of the mutant equals to or slightly surpasses that of the parent. Sakata-Mezuru has been registered in February of 2001 and officially released. (author)

  8. Different Aluminum Tolerance among Indica, Japonica and Hybrid Rice Varieties

    Directory of Open Access Journals (Sweden)

    Shu Chang

    2015-05-01

    Full Text Available Hydroponic cultures were conducted to compare the aluminum (Al tolerance among different rice (Oryza sativa L. varieties, including indica, japonica and their hybrids. The results showed that the root growth of rice plant was inhibited in different degrees among Al treated varieties. The Al tolerance observed through relative root elongation indicated that five japonica varieties including Longjing 9, Dharial, LGC 1, Ribenyou and Koshihikari were relatively more tolerant than indica varieties. Most indica varieties in this study, such as Aus 373 and 9311 (awnless, were sensitive to Al toxicity. The Al tolerance of most progenies from japonica × indica or indica × japonica crosses was constantly consistent with indica parents. The differences of Al tolerance among Longjing 9 (japonica, Yangdao 6 (indica and Wuyunjing 7 (japonica were studied. Biomass and the malondial-dehyde content of Yangdao 6 under Al exposure decreased and increased, respectively, while there was no significant effect on those of Longjing 9 and Wuyunjing 7. Remarkable reduction of root activities was observed in all these three rice varieties. Significantly higher Al content in roots was found in Yangdao 6 compared to Longjing 9 or Wuyunjing 7.

  9. A New High Yielding and Lodging-Tolerant Rice Cultivar, 'Woncheongbyeo' Mutated from Chucheongbyeo

    International Nuclear Information System (INIS)

    Kang, S.Y.; Shin, I.C.; Lee, Y.I.; Song, H.S.; Lee, S.J.; Kim, D.S.; Lee, G.J.; Cho, Y.C.

    2006-01-01

    'Woncheongbyeo' is a new japonica rice (Oryza sativa L.) cultivar developed by mutation techniques from Chucheongbyeo. Chucheongbyeo seeds were irradiated with 300 Gy gamma ray (83.3 rad/min) emitted from ∨60Co at a radiation facility of the Korea Atomic Energy Research Institute (KAERI) in 1992. Compared to Chucheongbyeo, 'Woncheongbyeo' has a short stature as 64 cm in culm length, resistance to lodging and 3-days-earlier heading date. It has considerably erect pubescent leaf blades and a tough culm with a good canopy architecture

  10. Expression patterns of ABA and GA metabolism genes and hormone levels during rice seed development and imbibition: a comparison of dormant and non-dormant rice cultivars.

    Science.gov (United States)

    Liu, Yang; Fang, Jun; Xu, Fan; Chu, Jinfang; Yan, Cunyu; Schläppi, Michael R; Wang, Youping; Chu, Chengcai

    2014-06-20

    Seed dormancy is an important agronomic trait in cereals. Using deep dormant (N22), medium dormant (ZH11), and non-dormant (G46B) rice cultivars, we correlated seed dormancy phenotypes with abscisic acid (ABA) and gibberellin (GA) metabolism gene expression profiles and phytohormone levels during seed development and imbibition. A time course analysis of ABA and GA content during seed development showed that N22 had a high ABA level at early and middle seed developmental stages, while at late developmental stage it declined to the level of ZH11; however, its ABA/GA ratio maintained at a high level throughout seed development. By contrast, G46B had the lowest ABA content during seed development though at early developmental stage its ABA level was close to that of ZH11, and its ABA/GA ratio peaked at late developmental stage that was at the same level of ZH11. Compared with N22 and G46B, ZH11 had an even and medium ABA level during seed development and its ABA/GA ratio peaked at the middle developmental stage. Moreover, the seed development time-point having high ABA/GA ratio also had relatively high transcript levels for key genes in ABA and GA metabolism pathways across three cultivars. These indicated that the embryo-imposed dormancy has been induced before the late developmental stage and is determined by ABA/GA ratio. A similar analysis during seed imbibition showed that ABA was synthesized in different degrees for the three cultivars. In addition, water uptake assay for intact mature seeds suggested that water could permeate through husk barrier into seed embryo for all three cultivars; however, all three cultivars showed distinct colors by vanillin-staining indicative of the existence of flavans in their husks, which are dormancy inhibition compounds responsible for the husk-imposed dormancy. Copyright © 2014. Published by Elsevier Ltd.

  11. Improving restorer line of hybrid rice by irradiation

    International Nuclear Information System (INIS)

    Guo Guangrong; Yi Weiping; Liu Wuquan

    1995-03-01

    The work for improving restorer line of hybrid rice has been done. The results showed the radiosensitivity of foreign varieties overtakes Chinese ones at average level. Because of their different blood relationship, there are various situation on foreign varieties, i.e. varieties from IR system are not sensitive, Shui-yun system are second and Miyang system are sensitive. The radiosensitivity for restorer lines of hybrid F 0 overtakes one for F 1 . According to this results. We have put forward the point of view 'Multi-gene type blend system'. M 2 mutant frequency of restorer line was investigated. The results showed: there was a little difference between the total mutant frequencies from the different varieties. But, there may be difference in some characters by over thirty times between them. So a problem, worthy to be further studied is proposed that do the differences of radiosensitivity between varieties relate to the mutant frequency of these characters? Various mutants were obtained by irradiation treatment, among which a few mutants changed to maintainer line because losing restorer genes, other more mutants still were restorer lines. New combinations developed by these new mutant restorer lines have strong heterosis. The optimum combinations have been utilized in rice production. (7 tabs.)

  12. Comparative Phosphoproteomic Analysis of the Developing Seeds in Two Indica Rice ( Oryza sativa L.) Cultivars with Different Starch Quality.

    Science.gov (United States)

    Pang, Yuehan; Zhou, Xin; Chen, Yaling; Bao, Jinsong

    2018-03-21

    Protein phosphorylation plays important roles in regulation of various molecular events such as plant growth and seed development. However, its involvement in starch biosynthesis is less understood. Here, a comparative phosphoproteomic analysis of two indica rice cultivars during grain development was performed. A total of 2079 and 2434 phosphopeptides from 1273 and 1442 phosphoproteins were identified, covering 2441 and 2808 phosphosites in indica rice 9311 and Guangluai4 (GLA4), respectively. Comparative analysis identified 303 differentially phosphorylated peptides, and 120 and 258 specifically phosphorylated peptides in 9311 and GLA4, respectively. Phosphopeptides in starch biosynthesis related enzymes such as AGPase, SSIIa, SSIIIa, BEI, BEIIb, PUL, and Pho1were identified. GLA4 and 9311 had different amylose content, pasting viscosities, and gelatinization temperature, suggesting subtle difference in starch biosynthesis and regulation between GLA4 and 9311. Our study will give added impetus to further understanding the regulatory mechanism of starch biosynthesis at the phosphorylation level.

  13. Construction of a male sterility system for hybrid rice breeding and seed production using a nuclear male sterility gene.

    Science.gov (United States)

    Chang, Zhenyi; Chen, Zhufeng; Wang, Na; Xie, Gang; Lu, Jiawei; Yan, Wei; Zhou, Junli; Tang, Xiaoyan; Deng, Xing Wang

    2016-12-06

    The breeding and large-scale adoption of hybrid seeds is an important achievement in agriculture. Rice hybrid seed production uses cytoplasmic male sterile lines or photoperiod/thermo-sensitive genic male sterile lines (PTGMS) as female parent. Cytoplasmic male sterile lines are propagated via cross-pollination by corresponding maintainer lines, whereas PTGMS lines are propagated via self-pollination under environmental conditions restoring male fertility. Despite huge successes, both systems have their intrinsic drawbacks. Here, we constructed a rice male sterility system using a nuclear gene named Oryza sativa No Pollen 1 (OsNP1). OsNP1 encodes a putative glucose-methanol-choline oxidoreductase regulating tapetum degeneration and pollen exine formation; it is specifically expressed in the tapetum and miscrospores. The osnp1 mutant plant displays normal vegetative growth but complete male sterility insensitive to environmental conditions. OsNP1 was coupled with an α-amylase gene to devitalize transgenic pollen and the red fluorescence protein (DsRed) gene to mark transgenic seed and transformed into the osnp1 mutant. Self-pollination of the transgenic plant carrying a single hemizygous transgene produced nontransgenic male sterile and transgenic fertile seeds in 1:1 ratio that can be sorted out based on the red fluorescence coded by DsRed Cross-pollination of the fertile transgenic plants to the nontransgenic male sterile plants propagated the male sterile seeds of high purity. The male sterile line was crossed with ∼1,200 individual rice germplasms available. Approximately 85% of the F1s outperformed their parents in per plant yield, and 10% out-yielded the best local cultivars, indicating that the technology is promising in hybrid rice breeding and production.

  14. Economics of weed suppressive rice cultivars in flood- and furrow-irrigated systems

    Science.gov (United States)

    Weeds are a major constraint to rice production. In the U.S, weeds in rice are controlled primarily with synthetic herbicides. Intensive herbicide application in rice also has many potential drawbacks, resulting in environmental pollution, human health concerns, and development of weed resistance. B...

  15. Inheritance of p,p'-DDE phytoextraction ability in hybridized Cucurbita pepo cultivars.

    Science.gov (United States)

    White, Jason C

    2010-07-01

    Cucurbita pepo ssp pepo (zucchini) has been shown to uniquely phytoextract percent level amounts of dichlorodiphenyldichloroethylene (DDE) and other organic contaminants from soil. Since C. pepo ssp ovifera (squash) does not have this ability, a three-year field trial was conducted to follow the inheritance pattern of DDE accumulation for cross pollinated C. pepo cultivars. Parental zucchini and squash cultivars (3 each) had stem-to-soil bioconcentration factors (BCF, contaminant ratio of stem to soil) of 16 and 1.7, respectively, and phytoextracted 1.8 and 0.18% of the DDE from soil. The 18 possible first filial (F1) hybrids of zucchini and squash accumulated significantly different DDE levels than the respective parents. The zucchini F1 hybrid (zucchini pollinated with squash) stem BCFs and percent phytoextraction values were 10 and 0.96, respectively, or 36% and 47% less than the parental zucchini. The squash F1 hybrid (squash pollinated with zucchini) stem BCFs and percent phytoextraction values were 8.3 and 0.68, respectively, or 490% and 370% greater than the parental squash. When backcrossed (BC) with the original parent, the nine zucchini F1 BC cultivars did not regain the capability to take up DDE; stem BCFs and percent phytoextraction values were equivalent to those of the F1 generation. However, the nine squash F1 BC cultivars lost much of the DDE uptake capability of the F1 generation; stem BCFs and percent phytoextraction values were intermediate but closer to those of the parental squash. The inheritance patterns suggest single locus control for persistent organic pollutant (POP) uptake ability in C. pepo ssp pepo.

  16. The Organelle Genomes of Hassawi Rice (Oryza sativa L.) and Its Hybrid in Saudi Arabia: Genome Variation, Rearrangement, and Origins

    Science.gov (United States)

    Zhang, Tongwu; Hu, Songnian; Zhang, Guangyu; Pan, Linlin; Zhang, Xiaowei; Al-Mssallem, Ibrahim S.; Yu, Jun

    2012-01-01

    Hassawi rice (Oryza sativa L.) is a landrace adapted to the climate of Saudi Arabia, characterized by its strong resistance to soil salinity and drought. Using high quality sequencing reads extracted from raw data of a whole genome sequencing project, we assembled both chloroplast (cp) and mitochondrial (mt) genomes of the wild-type Hassawi rice (Hassawi-1) and its dwarf hybrid (Hassawi-2). We discovered 16 InDels (insertions and deletions) but no SNP (single nucleotide polymorphism) is present between the two Hassawi cp genomes. We identified 48 InDels and 26 SNPs in the two Hassawi mt genomes and a new type of sequence variation, termed reverse complementary variation (RCV) in the rice cp genomes. There are two and four RCVs identified in Hassawi-1 when compared to 93–11 (indica) and Nipponbare (japonica), respectively. Microsatellite sequence analysis showed there are more SSRs in the genic regions of both cp and mt genomes in the Hassawi rice than in the other rice varieties. There are also large repeats in the Hassawi mt genomes, with the longest length of 96,168 bp and 96,165 bp in Hassawi-1 and Hassawi-2, respectively. We believe that frequent DNA rearrangement in the Hassawi mt and cp genomes indicate ongoing dynamic processes to reach genetic stability under strong environmental pressures. Based on sequence variation analysis and the breeding history, we suggest that both Hassawi-1 and Hassawi-2 originated from the Indonesian variety Peta since genetic diversity between the two Hassawi cultivars is very low albeit an unknown historic origin of the wild-type Hassawi rice. PMID:22870184

  17. Single rice growth period was prolonged by cultivars shifts, but yield was damaged by climate change during 1981-2009 in China, and late rice was just opposite.

    Science.gov (United States)

    Tao, Fulu; Zhang, Zhao; Shi, Wenjiao; Liu, Yujie; Xiao, Dengpan; Zhang, Shuai; Zhu, Zhu; Wang, Meng; Liu, Fengshan

    2013-10-01

    Based on the crop trial data during 1981-2009 at 57 agricultural experimental stations across the North Eastern China Plain (NECP) and the middle and lower reaches of Yangtze River (MLRYR), we investigated how major climate variables had changed and how the climate change had affected crop growth and yield in a setting in which agronomic management practices were taken based on actual weather. We found a significant warming trend during rice growing season, and a general decreasing trend in solar radiation (SRD) in the MLRYR during 1981-2009. Rice transplanting, heading, and maturity dates were generally advanced, but the heading and maturity dates of single rice in the MLRYR (YZ_SR) and NECP (NE_SR) were delayed. Climate warming had a negative impact on growth period lengths at about 80% of the investigated stations. Nevertheless, the actual growth period lengths of YZ_SR and NE_SR, as well as the actual length of reproductive growth period (RGP) of early rice in the MLRYR (YZ_ER), were generally prolonged due to adoption of cultivars with longer growth period to obtain higher yield. In contrast, the actual growth period length of late rice in the MLRYR (YZ_LR) was shortened by both climate warming and adoption of early mature cultivars to prevent cold damage and obtain higher yield. During 1981-2009, climate warming and decrease in SRD changed the yield of YZ_ER by -0.59 to 2.4%; climate warming during RGP increased the yield of YZ_LR by 8.38-9.56%; climate warming and decrease in SRD jointly reduced yield of YZ_SR by 7.14-9.68%; climate warming and increase in SRD jointly increased the yield of NE_SR by 1.01-3.29%. Our study suggests that rice production in China has been affected by climate change, yet at the same time changes in varieties continue to be the major factor driving yield and growing period trends. © 2013 John Wiley & Sons Ltd.

  18. [Effects of Rice Cultivar and Typical Soil Improvement Measures on the Uptake of Cd in Rice Grains].

    Science.gov (United States)

    Wang, Mei-e; Peng, Chi; Chen, Wei-ping

    2015-11-01

    Cadmium pollution of rice is a big problem in agricultural food safety. The accident "Cd rice" occurred last year in Youxian County, Hunan Province caused serious social panic. In this study, trials on "Cd rice" controlling techniques specific to the Cd pollution in paddy soil in Youxian were investigated. It was suggested that the average Cd contents in rice grains of the rice variety "Zhu Liang You 06" in Datongqiao and Wangling were 0.167 and 0.127 mg x kg(-1), respectively, which were only equal to 20% of the contents of other varieties. The trials for stabilizing agents revealed that treatments of lime and mineral fertilizer decreased Cd contents in rice grains to 20-30% of the control. Plastic film-mulched treatment decreased the rice grain Cd to 50%. And combined treatment of plastic film-mulched and biochar and silicon foliar-fertilizer decreased 80% of rice Cd content. Single treatments of silicon foliar-fertilizer and combined treatment of silicon foliar-fertilizer and topdressing fertilizer decreased more than 90% of Cd content. Results of BCR revealed that the percentage of cationic exchangeable and/or carbonate associated Cd fraction was more than 55% for most of the soil samples. Lime treatment significantly decreased the percentage of cationic exchangeable and/or carbonate and oxides of Fe and Mn associated Cd and increased the crystalline structure of clay minerals associated Cd. The change rate reached about 20%. Our results suggested concentration of soil Cd and pH were the two significant factors impacting the uptake of Cd by rice grains.

  19. Somatic embryogenesis and in-vitro regeneration of rice (Oryza sativa L.) cultivars under one-step and multiple-step salinity stresses

    DEFF Research Database (Denmark)

    Khattak, Mohammad S. K.; Abiri, Rambod; Valdiani, Alireza

    2017-01-01

    The present study aimed to examine the effect of one-step and multiple-step salinity stress on the somatic embryogenesis of rice cultivars within the solid and liquid (cell suspension) culture media conditions. Five rice cultivars, including Puteh Perak, Mahsuri, Basmati-370, Nona Bokra and Khari......, and significant morphological changes were observed. In contrast, the multiple-step NaCl treatment of the calli and cell suspensions led to higher growth of the cultures in the presence of NaCl compared to the controls. The solid MS media, containing 3 μM IAA and 40 μM Kinetin performed as the best media...

  20. Development of eggplant hybrid cultivar ‘BATEM FILIZI’ and determination of yield performance

    Directory of Open Access Journals (Sweden)

    Hatice Filiz BOYACI

    2014-12-01

    Full Text Available Eggplant (Solanum melongena L. cultivation is an important part of vegetable production in Turkey. It is highly affected by abiotic stress factors such as low temperatures during growth and development. The present study was aimed to improve new hybrid varieties with high quality and fruit setting under undesirable environmental conditions in eggplant. The 39 inbred lines were developed from eggplant genepool by using pedigree breeding method at the Bati Akdeniz Agricultural Research Institute. They were characterized morphologically and evaluated for phylogenetic relationship among them. Selected seven lines were crossed each other to obtain F1 hybrids. Thirteen hybrids from these crosses were examined for their rate of heterosis and heterobeltiosis. These hybrids were not suitable for market demands although F1 hybrids including P350 as parental line had high heterosis rate. Oval fruit shaped P350 inbred line as female parent showed good performance and crossed with long fruit shaped P599 inbred line. The resultant F1 hybrid cultivar higher yielding, suitable for production under greenhouse and highly adaptable was registered with the name of BATEM FILIZI. It is recommended that this hybrid can be used in greenhouse production especially in single crop season.

  1. Distribution of 45S rDNA in Modern Rose Cultivars (Rosa hybrida), Rosa rugosa, and Their Interspecific Hybrids Revealed by Fluorescence in situ Hybridization.

    Science.gov (United States)

    Ding, Xiao-Liu; Xu, Ting-Liang; Wang, Jing; Luo, Le; Yu, Chao; Dong, Gui-Min; Pan, Hui-Tang; Zhang, Qi-Xiang

    2016-01-01

    To elucidate the evolutionary dynamics of the location and number of rDNA loci in the process of polyploidization in the genus Rosa, we examined 45S rDNA sites in the chromosomes of 6 modern rose cultivars (R. hybrida), 5 R. rugosa cultivars, and 20 hybrid progenies by fluorescence in situ hybridization. Variation in the number of rDNA sites in parents and their interspecific hybrids was detected. As expected, 4 rDNA sites were observed in the genomes of 4 modern rose cultivars, while 3 hybridization sites were observed in the 2 others. Two expected rDNA sites were found in 2 R. rugosa cultivars, while in the other 3 R. rugosa cultivars 4 sites were present. Among the 20 R. hybrida × R. rugosa offspring, 13 carried the expected number of rDNA sites, and 1 had 6 hybridization sites, which exceeded the expected number by far. The other 6 offspring had either 2 or 3 hybridization sites, which was less than expected. Differences in the number of rDNA loci were observed in interspecific offspring, indicating that rDNA loci exhibit instability after distant hybridization events. Abnormal chromosome pairing may be the main factor explaining the variation in rDNA sites during polyploidization. © 2016 S. Karger AG, Basel.

  2. Optimizing hill seeding density for high-yielding hybrid rice in a single rice cropping system in South China.

    Directory of Open Access Journals (Sweden)

    Danying Wang

    Full Text Available Mechanical hill direct seeding of hybrid rice could be the way to solve the problems of high seeding rates and uneven plant establishment now faced in direct seeded rice; however, it is not clear what the optimum hill seeding density should be for high-yielding hybrid rice in the single-season rice production system. Experiments were conducted in 2010 and 2011 to determine the effects of hill seeding density (25 cm×15 cm, 25 cm×17 cm, 25 cm×19 cm, 25 cm×21 cm, and 25 cm×23 cm; three to five seeds per hill on plant growth and grain yield of a hybrid variety, Nei2you6, in two fields with different fertility (soil fertility 1 and 2. In addition, in 2012 and 2013, comparisons among mechanical hill seeding, broadcasting, and transplanting were conducted with three hybrid varieties to evaluate the optimum seeding density. With increases in seeding spacing from 25 cm×15 cm to 25 cm×23 cm, productive tillers per hill increased by 34.2% and 50.0% in soil fertility 1 and 2. Panicles per m2 declined with increases in seeding spacing in soil fertility 1. In soil fertility 2, no difference in panicles per m2 was found at spacing ranging from 25 cm×17 cm to 25 cm×23 cm, while decreases in the area of the top three leaves and aboveground dry weight per shoot at flowering were observed. Grain yield was the maximum at 25 cm×17 cm spacing in both soil fertility fields. Our results suggest that a seeding density of 25 cm×17 cm was suitable for high-yielding hybrid rice. These results were verified through on-farm demonstration experiments, in which mechanical hill-seeded rice at this density had equal or higher grain yield than transplanted rice.

  3. Studies on combining ability and heritability of milling and physical properties in indica hybrid rice

    International Nuclear Information System (INIS)

    Zhang Lihua; Wang Linyou; Wang Jianjun

    2003-01-01

    14 different qualities parents of indica hybrid rice, including 7 CMS lines and 7 restorers, were chosen to analyze the combining ability of milling property and physical property by way of p x q incomplete diallel cross (NC II) design. The results showed that: 1) Both general combining ability (gca) and specific combining ability (sca) were highly significant in all 12 characters; the genetic additive effects was principal in brown rice length (BRL), brown rice width (BRW), ratio of length to width of brown rice (RLWBR), milled rice length (MRL), milled rice width (MRW), ratio of length to width of milled rice (RLWMR) and chalkyness (CN); while the nonadditive effects were greater in brown rice rate (BRR), milled rice rate (MRR), head rice rate (HRR), chalky rice percentage (CRP) and area of chalky rice (ACR). 2) Through the analysis of the contribution ratio of the male, female and their interaction to the total variance of the quality characters in F 1 hybrids, the results showed that BRR, MRR, BRL, MRL and ACR were influenced more greatly by restorer line than by CMS line, but the others were influenced more greatly by CMS line than by restorer line. 3) The gca and sca effects were independent each other, which suggests that it is essential to make widely testcrosses in the selection of hybrid combinations. There existed a positive correlation between gca and phenotypic value of parents, which indicates that great attention must be paid to the improvement of parent own characters in hybrid rice breeding. 4) BRL, BRW, RLWBR, MRL, MRW and RLWMR had higher narrow heritabilities (h N 2 ), and these characters may be used as indirect traits in early breeding generation

  4. Evaluation of indicators to determine black sigatoka susceptibility in five banana hybrid cultivars ( Mycosphaerella fijiensis Morelet

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    Reinaldo Pérez Armas

    2014-10-01

    Full Text Available This work had the objective of determining the variation of growth, development and yields indicators of five banana hybrid cultivars. The research was carried in the Agroindustrial Farm Marta Abreu, Cienfuegos, in a carbonated Brown soil. It was made a characterization of the soil and the climatic variables. A field experiment was developed with a design in blocks at random with four repetitions with five banana cultivars as treatments (‘FHIA-18’, ‘FHIA-02’, ‘FHIA-01’, ‘SH-3436 L-9’ and ‘FHIA-23’ . The plots had an area of 56 m2 with 16 plants, been evaluated eight for a total 32 plants for cultivar. The variable evaluated were the spotty youngest leaf, number of leaf by plant, incubation time (PI, evolution time of symptoms (TES and developing time of symptoms (TED, severity index (IS, active photosynthetic index (INHE and infection relative index. The cultivars FHIA-23 and SH 3436 L9 presented a hither time of development of the disease. In a general the more susceptible cultivar to the black Sigatoka under of the farm condition was FHIA-23. The clones FHIA-18, FHIA-01 and FHIA-02 presented the best behavior in the spotted youngest leaf and the number of leaf up to the flowering and the harvest time. The clones FHIA-01 and FHIA-18 have the better response to Black Sigatoka attending to the incubation period, the evolution time of the symptom and develo pment time of the disease

  5. Factors affecting variation in CH4 emission from paddy soils grown with different rice cultivars: A pot experiment

    Science.gov (United States)

    Watanabe, Akira; Kimura, Makoto

    1998-08-01

    The growth of rice plants greatly influences CH4 emission from paddy fields through the supply of organic materials such as root exudates and sloughed tissues, the release of oxygen to the root environment, and the transfer of CH4 from the rhizosphere into the atmosphere through the aerenchyma. In the present pot experiments, the effects of the release of water-soluble organic substances from roots, the air space in roots, and the CH4-oxidizing capacity of roots on intervarietal differences in CH4 emission were examined using three Japonica type cultivars (Norin 25, Nipponbare, and Aoinokaze), which differ in morphological properties. The CH4 emission rates varied among the cultivars from mid-July (tillering stage) to the beginning of September (heading stage).Total CH4 emission throughout the rice growth period was largest for Norin 25, followed by Nipponbare, and Aoinokaze. In August, the rate of release of water-soluble organic substances from roots was largest for Norin 25. The air space in roots was also largest in Norin 25 and least in Aoinokaze. The stable carbon isotopic ratios (δ13C) of CH4 in roots were 3-10‰ higher than those in soil in August. The difference in δ13C values of CH4 between roots and soil was largest for Aoinokaze and smallest for Norin 25. In September, the difference in δ13C values of CH4 between roots and soil became small (2-3‰). These findings suggest that the proportion of CH4 oxidation in the rhizosphere was largest in the cultivar which emitted the smallest amount of CH4 and that the proportion became smaller with continued plant growth.

  6. Performance of different rice cultivars and insecticides against tryporyza incertulas (walker) and cnaphalocrocis medinalis (guenee)

    International Nuclear Information System (INIS)

    Rashid, M.M.U.; Khattak, M.K.; Momin, A.; Amir, M.; Latif, A.

    2013-01-01

    Studies were conducted to determine the toxicity of Roll Up (7.2% G), Furadan (3G), Solomon (300-0-Teq), Belt (48% SC), Karuz (4% GR) and Shark Super (6% G) and relative resistance of rice varieties IRRI-6, KSK-282, DR-83, Basmati-370, Basmati-385 and Super Basmati against rice stem borer and rice leaf folder and their effect on yield ha/sup -1/. Roll Up and Shark Super ranked first in their efficacy against rice stem borer; as 0.64% and 0.63% dead hearts and 0.32 and 0.33% white heads were recorded, respectively, and which were significantly (P < 0.05) lower than control. Solomon with 0.73% infestation was the most effective insecticide against rice leaf folder. Rice varieties IRRI-6 and KSK-282 were the most resistant varieties against rice stem borer; as 14.73% and 18.34% dead hearts, and 4.33% and 4.77% white heads were significantly (P < 0.05) lower than the other tested varieties. Similarly IRRI-6, KSK-282 and DR-83 also showed resistance to rice leaf folder. Basmati-385 was the most susceptible variety against rice leaf folder. KSK-282 with 5656 kg ha/sup -1/ yield ranked first. Plots treated with shark super resulted in to highest (7014 kg ha/sup -1/) yield whereas; plots treated with Karuz resulted into lowest (5984 kg ha/sup -1/) yield. (author)

  7. Principal Component and Cluster Analysis as a Tool in the Assessment of Tomato Hybrids and Cultivars

    Directory of Open Access Journals (Sweden)

    G. Evgenidis

    2011-01-01

    Full Text Available Determination of germplasm diversity and genetic relationships among breeding materials is an invaluable aid in crop improvement strategies. This study assessed the breeding value of tomato source material. Two commercial hybrids along with an experimental hybrid and four cultivars were assessed with cluster and principal component analyses based on morphophysiological data, yield and quality, stability of performance, heterosis, and combining abilities. The assessment of commercial hybrids revealed a related origin and subsequently does not support the identification of promising offspring in their crossing. The assessment of the cultivars discriminated them according to origin and evolutionary and selection effects. On the Principal Component 1, the largest group with positive loading included, yield components, heterosis, general and specific combining ability, whereas the largest negative loading was obtained by qualitative and descriptive traits. The Principal Component 2 revealed two smaller groups, a positive one with phenotypic traits and a negative one with tolerance to inbreeding. Stability of performance was loaded positively and/or negatively. In conclusion, combing ability, yield components, and heterosis provided a mechanism for ensuring continued improvement in plant selection programs.

  8. Seed Germination Behaviors Of Some Aerobic Rice Cultivars Oryza Sativa L After Priming With Polyethylene Glycol-8000 Peg-8000

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    Elkheir H.A

    2015-08-01

    Full Text Available Seed Priming Is Famous Technique To Accelerate Seed Germination Behaviors. This Experiment Was Conducted To Study The Effect Of Polyethylene Glycol-8000 Peg-8000 As Priming Agent On Seed Germination Behavior Of Some Aerobic Rice Cultivars Oryza Sativa L. Experiment Was Carried Out By Using Two-Factor Three Aerobic Rice Cultivars And Peg With Four Replications Which Arranged In Factorial System Design And Conducted With Completely Randomized Design. The Factor Was Varieties Which Were Inpago 8 V1 Ir64 V2 And Situbagendit V3 Combine With 4 Levels Of Peg Concentrations 0100 And 200 Gl-1 And Control With No Treatment. Experiment Was Repeated 4 Times So Total Number Of Experimental Units Were 48. Germination Parameters Measured Were Germination Percentage Germination Index Days Of 50 Germination Seedling Fresh Weight Mg Seedling Shoot Fresh Weight And Root Fresh Weight Mg Seedling Dry Weigh Mg Seedling Shoot Dry Weight And Root Dry Weight Mg ShootRoot Ratio Seedling Length Cm Seedling Root Length Cm And Shoot Length Cm And Seed Vigor Index. The Results Indicated That Seed Priming Significantly Affected Germination Behaviors Compared With Control Depending Upon Varieties. The Highest Germination Was Obtained Under Laboratory And Greenhouse Condition By The Treatment Of Peg 200 G L-1 On The Situbagendit And Ir-64 Variety 90.25 And 93.33 Respectively Compared To Control In Inpago-8 In Both Laboratory 75.75 And Greenhouse 80 . As Implementation To Increase Seed And Seedling Vigor Of Rice It Is A Best Practice To Use Peg Priming With 200 Gl-1 Solutions Depend Upon Varietal Response And We Suggest That More Research About The Effect Of Peg As Seed Priming Techniques On Seed Germination Behavior Of Many Grain Crops Is Needed To Confirm The Methodology.

  9. Induction of resistance to blast disease in an elite rice cultivar 'IR 50'

    International Nuclear Information System (INIS)

    Sarma, N.P.; Rao, G.J.N.; Row, K.V.S.R.K.

    2001-01-01

    Full text: One of the most promising techniques for producing disease resistant forms of plants is the use of mutagenic agents. It has been demonstrated by several workers that genetic variability for several desired characters can be induced successfully through mutations and its practical value in plant improvement programmes has been well established. The main advantage of mutation breeding is the possibility of improving one or two characters without changing the rest of the genotype. The elite cultivar, 'IR 50' (IR 2153-14-1-6-2/IR 28//IR 36) was developed at IRRI, Los Banos, The Philippines and was released in India for the State of Tamil Nadu in 1982. It is highly responsive to fertilizer, records high yields and possesses good grain characters. It matured in just more than 100 days and was ideal for both samba and navarai seasons in Tamil Nadu. But, the cultivar was shown to be highly susceptible to blast (causative organism Magnaportha grisea) causing extensive losses year after year. With the objective of developing high yielding, blast tolerant mutant lines from IR 50, the mutation approach was adopted and both physical (gamma-rays from 60 Co) and chemical mutagens (EMS - ethyl methanesulphonate and sodium azide) were employed on dry seeds. The M1 generation was grown in closely spaced plants. One hundred and sixty-eight derived families were grown in M 2 . In M 3 generation, 128 M 3 families were further selected for evaluation in M4 and M5. Based on evaluation of yield and other attributes, a total of 85 mutants were finally selected and evaluated for their stability. In selection of the mutants, it was ensured that all the selected mutants resemble the parent for both agronomic and quality characteristics. The evaluation of these mutant lines for the level of tolerance to blast disease was conducted at CRRI over a number of years under both artificial and natural conditions. These mutant lines showed varied levels of tolerance to blast in comparison

  10. Studies on optimum harvest time for hybrid rice seed.

    Science.gov (United States)

    Fu, Hong; Cao, Dong-Dong; Hu, Wei-Min; Guan, Ya-Jing; Fu, Yu-Ying; Fang, Yong-Feng; Hu, Jin

    2017-03-01

    Timely harvest is critical for hybrid rice to achieve maximum seed viability, vigor and yield. However, how to predict the optimum harvest time has been rarely reported so far. The seed vigor of Zhuliangyou 06 (ZLY06) increased and reached the highest level at 20 days after pollination (DAP), when seed moisture content had a lower value, which was maintained until final seed maturation. For Chunyou 84 (CY84), seed vigor, fresh and dry weight had relatively high values at 25 DAP, when seed moisture content reached the lowest value and changed slightly from 25 to 55 DAP. In both hybrid rice varieties, seed glume chlorophyll content declined rapidly from 10 to 30 DAP and remained at a very low level after 35 DAP. Starch content exhibited an increasing trend during seed maturation, while both soluble sugar content and amylase activity decreased significantly at the early stages of seed development. Moreover, correlation analyses showed that seed dry weight, starch content and superoxide dismutase activity were significantly positively correlated with seed vigor. In contrast, chlorophyll content, moisture content, soluble sugar, soluble protein, abscisic acid, gibberellin content, electrical conductivity, catalase and ascorbate peroxidase activities were significantly negatively correlated with seed vigor. Physiological and biochemical parameters were obviously more closely related with seed vigor than with seed germinability during seed development. Seed vigor could be better used as a comprehensive factor to predict the optimum seed harvest time. It is suggested that for ZLY06 seeds could be harvested as early as 20 DAP, whereas for CY84 the earliest optimum harvest time was 25 DAP. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  11. Cultivares de arroz irrigado e nutrientes na água de drenagem em diferentes sistemas de cultivos Irrigated rice cultivars and drainnage water nutrient under differnt managements systems

    Directory of Open Access Journals (Sweden)

    Lauro Weber

    2003-02-01

    components of four irrigated rice cultivars under different management systems, as well as, to measure the concentration of nutrients in the initial drainage water. The research was conducted during the 1998/99 growing season on a lowland area on a PLANOSOIL located at the Federal University of Santa Maria-RS, Brazil. The rice cultivars were IRGA 417, EL PASO 144, BRS TAIM and EPAGRI 108. The management systems were: conventional and minimum tillage and pre-germinated and "mix" of pre-germinated and seedlings transplants. The experimental design was a randomized aplit block with four replications. The conventional and minimum tillage were seeded in November 01st, 1998 and the pre-germinated and mix of pre-germinated and seedlings transplants were estabhished in November 18th, 1998. Seed yield was affected by management system except for the cultivar EL PASO 144 that had the same yield regardless treatments. EPAGRI 108 had the highest average yields, 8349kg ha-1. The highest number of panicles per square meter was observed in the pre-germinated and mix pre-germinated systems. The transplanted seedlings had the highest number of seeds per panicles. Regardless the management systems, EL PASO 144 presented thehighest number of seeds per panicle and EPAGRI 108 the heavier seeds. Nutrient concentration in the initial dreinage water was similar in all systems with average N, P, K, Ca, Mg and Fe concentrations of 5.02, 2.06, 10.33, 6.38, 3.51 and 2.56 mg l-1, respectively.

  12. Asian wild rice is a hybrid swarm with extensive gene flow and feralization from domesticated rice

    OpenAIRE

    Wang, Hongru; Garrett Vieira, Filipe Jorge; Crawford, Jacob E.; Chu, Chengcai; Nielsen, Rasmus

    2017-01-01

    The domestication history of rice remains controversial, with multiple studies reaching different conclusions regarding its origin(s). These studies have generally assumed that populations of living wild rice, O. rufipogon, are descendants of the ancestral population that gave rise to domesticated rice, but relatively little attention has been paid to the origins and history of wild rice itself. Here, we investigate the genetic ancestry of wild rice by analyzing a diverse panel of rice genome...

  13. Eficiência do uso e resposta à aplicação de fósforo de cultivares de arroz em solos de terras altas Use efficiency and response to phosphorus of application rice cultivars in highlands soils

    Directory of Open Access Journals (Sweden)

    Eliane Aparecida Rotili

    2010-01-01

    Full Text Available Objetivou-se com este trabalho estudar a eficiência e resposta quanto ao uso de fósforo de cultivares de arroz em solos de terras altas no sul do Estado de Tocantins. Os tratamentos envolveram seis cultivares comerciais de arroz (BRS-Bonança BRS-Caiapó, BRS-Sertaneja, BRSMG-Curinga, BRSMG-Conai e BRS-Primavera, que foram cultivadas em dois ambientes distintos. Para simular ambientes com baixo e alto nível de fósforo, foram utilizadas as doses 20 e 120 kg ha-1 de P2O5. O delineamento experimental utilizado foi o de blocos casualizados, com quatro repetições. Através da produtividade de grãos, classificaram-se as cultivares quanto à eficiência no uso e resposta à aplicação do fósforo. A cultivar BRS-Bonança foi mais eficiente quanto ao uso de fósforo e responsiva à sua aplicação.This research's objective was to study the efficiency in the usage of phosphorus by rice cultivars in highland soils in the South of Tocantins State. The experiments evaluated six commercial cultivars of rice (BRS-Bonança BRS-Caiapó, BRS-Sertaneja, BRSMG-Curinga, BRSMG-Conai and BRS-Primavera, grown in areas with high and low phosphorus application: 20 and 120 kg ha-1 of P2O5. The experiments were carried out in a completely randomized blocks design, with four replicates. Based on grain yield, cultivars were classified in respect to the efficiency and response to phosphorus fertilization. The cultivar BRS-Bonança presented the highest phosphorus use efficiency and was the most responsive.

  14. Effect of elevated [CO2 ] on yield, intra-plant nutrient dynamics, and grain quality of rice cultivars in Eastern India.

    Science.gov (United States)

    Jena, Usha Rani; Swain, Dillip Kumar; Hazra, K K; Maity, Mrinal K

    2018-05-16

    Climate models predict an increase in global temperature in response to a doubling of atmospheric [CO 2 ] that may impact future rice production and quality. In this study, the effect of elevated [CO 2 ] on yield, nutrient acquisition and utilization, and grain quality of rice genotypes was investigated in subtropical climate of eastern India (Kharagpur). Three environments (open field, ambient, and elevated [CO 2 ]) were tested using four rice cultivars of eastern India. Under elevated [CO 2 ] (25% higher), yield of high yielding cultivars (HYCs) viz. IR 36, Swarna, and Swarna sub1 was significantly reduced (11-13%), whereas the yield increased (6-9%) for Badshabhog, a low-yielding aromatic cultivar. Elevated [CO 2 ] significantly enhanced K uptake (14-21%), but did not influence the uptake of total N and P. The nutrient harvest index and use efficiency values in HYCs were reduced under elevated [CO 2 ] indicating that nutrients translocation from source to sink (grain) was significantly reduced. An increase in alkali spreading value (10%) and reduction in grain protein (2-3%) and iron (5-6%) was also observed upon [CO 2 ] elevation. The study highlights the importance of nutrient management (increasing N rate for HYCs) and selective breeding of tolerant cultivar in minimizing the adverse effect of elevated [CO 2 ] on rice yield and quality. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  15. Induction of Xa10-like Genes in Rice Cultivar Nipponbare Confers Disease Resistance to Rice Bacterial Blight.

    Science.gov (United States)

    Wang, Jun; Tian, Dongsheng; Gu, Keyu; Yang, Xiaobei; Wang, Lanlan; Zeng, Xuan; Yin, Zhongchao

    2017-06-01

    Bacterial blight of rice, caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive bacterial diseases throughout the major rice-growing regions in the world. The rice disease resistance (R) gene Xa10 confers race-specific disease resistance to X. oryzae pv. oryzae strains that deliver the corresponding transcription activator-like (TAL) effector AvrXa10. Upon bacterial infection, AvrXa10 binds specifically to the effector binding element in the promoter of the R gene and activates its expression. Xa10 encodes an executor R protein that triggers hypersensitive response and activates disease resistance. 'Nipponbare' rice carries two Xa10-like genes in its genome, of which one is the susceptible allele of the Xa23 gene, a Xa10-like TAL effector-dependent executor R gene isolated recently from 'CBB23' rice. However, the function of the two Xa10-like genes in disease resistance to X. oryzae pv. oryzae strains has not been investigated. Here, we designated the two Xa10-like genes as Xa10-Ni and Xa23-Ni and characterized their function for disease resistance to rice bacterial blight. Both Xa10-Ni and Xa23-Ni provided disease resistance to X. oryzae pv. oryzae strains that deliver the matching artificially designed TAL effectors (dTALE). Transgenic rice plants containing Xa10-Ni and Xa23-Ni under the Xa10 promoter provided specific disease resistance to X. oryzae pv. oryzae strains that deliver AvrXa10. Xa10-Ni and Xa23-Ni knock-out mutants abolished dTALE-dependent disease resistance to X. oryzae pv. oryzae. Heterologous expression of Xa10-Ni and Xa23-Ni in Nicotiana benthamiana triggered cell death. The 19-amino-acid residues at the N-terminal regions of XA10 or XA10-Ni are dispensable for their function in inducing cell death in N. benthamiana and the C-terminal regions of XA10, XA10-Ni, and XA23-Ni are interchangeable among each other without affecting their function. Like XA10, both XA10-Ni and XA23-Ni locate to the endoplasmic reticulum (ER) membrane

  16. Pigment and Lovastatin content on the Red Rice cultivar Bah Butong and BP 1804 IF 9 which Fermented by Monascus purpureus Jmba

    Directory of Open Access Journals (Sweden)

    ERNAWATI KASIM

    2006-01-01

    Full Text Available Research on the red rice fermented by Monascus purpureus had been done. The rice consisted of 2 cultivars such as Bah Butong and BP 1804 IF 9. The aim of the research was to know the content of the pigment and lovastatin of the fermentation result/ angkak. Angkak was powdered by using blender. To measure the content of pigment, the powder was extracted by methanol. By using spectrophotometer the content of the pigment could be measured with 390 nm wave lengths for yellow pigment and 500 nm for the red pigment. For lovastatin the powder was extracted by acetonitrile and H2SO4. By using HPLC the content of lovastatin could be measured. The results showed that the highest pigment content for yellow pigment was on the PB 1804 IF 9 cultivar, and red pigment was on the Bah Butong cultivar. The highest lovastatin content was on the BP 1804 IF 9.

  17. Physicochemical studies on starches isolated from plantain cultivars, plantain hybrids and cooking bananas

    Energy Technology Data Exchange (ETDEWEB)

    Eggleston, G.; Akoni, S. (International Inst. of Tropical Agriculture, Ibadan (Nigeria)); Swennen, R. (Catholic Univ. of Leuven, Heverlee (Belgium). Lab. of Tropical Husbandry)

    1992-04-01

    Starches from mature, unripe fruit pulp of plantain cultivars (Musa supp., AAB group) representing the wide variability in Africa, tetraploid and diploid plantain hybrids and starchy cooking bananas (Musa spp., ABB group) were isolated and characterised. In general, studies revealed very compact irregularly shaped and sized granules, with low amylose content (9.11-17.16%), highly resistant to bacterial {alpha}-amylase attack; Brabender amylograms showed very restricted swelling type patterns with great stability and negligible retrogradation. Results indicate that differences in physico-chemical properties exist amongst the three Musa fruit group starches. Plantains represent a chemical/molecular homogeneous group, but heterogeneous for granule structure. Ploidy level affected hybrid properties. ABB cooking bananas starches exhibited highly pronounced restricted swelling and high gelatinisation and pasting temperatures, indicating a more ordered, very strongly bonded granule structure; chemical and physical properties varied considerably within the ABB genotype. (orig.).

  18. Características de plantas de cultivares de arroz irrigado relacionadas à habilidade competitiva com plantas concorrentes Characteristics of flooded rice cultivar plants related to competitive ability against weeds concurrent plants

    Directory of Open Access Journals (Sweden)

    N.G. Fleck

    2003-04-01

    Full Text Available Plantas que apresentam rápido crescimento tendem a ocupar precocemente nichos disponíveis, utilizando o espaço de suas vizinhas. Em geral, esses vegetais adquirem prioridade na utilização dos recursos do meio. O objetivo deste trabalho foi avaliar variações em características de crescimento de cultivares de arroz irrigado. Para isso, conduziu-se um experimento em campo na estação de crescimento de 2000/2001, em Cachoeirinha-RS. Investigou-se o comportamento de oito cultivares de arroz, cultivados em presença e ausência de plantas de arroz do cultivar EEA 406, simulando infestação de arroz-vermelho, estabelecida com densidade média de 30 plantas m-2. Entre 15 e 60 dias após a semeadura (DAS, avaliou-se a evolução de área foliar, estatura e massa aérea das plantas de arroz. Com esses dados, calcularam-se razão de área foliar (RAF, taxa de crescimento relativo (TCR e taxa de assimilação líquida (TAL dos cultivares. Os cultivares Ligeirinho e XL 6 apresentaram elevadas velocidades de ganho em área foliar, estatura e massa aérea; com isso, alcançaram as maiores coberturas do solo, juntamente com o cultivar IR 841. Por outro lado, os cultivares Bluebelle e Formosa mostraram lento crescimento absoluto no período avaliado, mas, em geral, apresentaram os maiores valores para TCR e TAL.Fast-growing plants tend to occupy available niches utilizing these spaces ahead of their neighbors. In general, these plants have priority over others in the use of environmental resources. The objective of this research was to evaluate variations in growth characteristics of flooded rice cultivars. A field experiment was carried out during the 2000/01 summer season, in Cachoeirinha, RS, Brazil. The behavior of eight rice cultivars, grown in the absence or presence of the EEA 406 rice genotype was investigated, simulating a red rice infestation, established at an average density of 30 plants m-2. From 15 to 60 days after seeding (DAS

  19. Antixenosis and Antibiosis Resistance in Rice Cultivars against Chilo suppressalis (Walker) (Lepidoptera: Crambidae).

    Science.gov (United States)

    Tabari, M A; Fathi, S A A; Nouri-Ganbalani, G; Moumeni, A; Razmjou, J

    2017-08-01

    The striped stem borer, Chilo suppressalis (Walker) (Lepidoptera: Crambidae), is an important pest afflicting rice in most rice-growing countries in the world. Deliniating the categories of resistance in rice genotypes under field conditions could be helpful in managment of this pest. Two categories of resistance, antixenosis and antibiosis, were examined in ten popular and diverse rice genotypes of different origin that had been selected for their resistance to the striped stem borer in a previous study. Significant differences were found between genotypes for the number of egg masses, number of eggs, preference index, larval and pupal weight, larval development time, larval survival rate, larval mine length, and leaf trichome density. It was found that the rice genotypes Novator, A7801, and Nemat had the more pronounced antixenosis-type resistance, whereas AB1 and Shirodi had better antiobiosis-type resistance. Interestingly, the rice genotype AN-74 for which Nemat is the parental line showed both types of resistance and could be effectively used in an integrated pest management of the rice striped stem borer.

  20. Workable male sterility systems for hybrid rice: Genetics, biochemistry, molecular biology, and utilization.

    Science.gov (United States)

    Huang, Jian-Zhong; E, Zhi-Guo; Zhang, Hua-Li; Shu, Qing-Yao

    2014-12-01

    The exploitation of male sterility systems has enabled the commercialization of heterosis in rice, with greatly increased yield and total production of this major staple food crop. Hybrid rice, which was adopted in the 1970s, now covers nearly 13.6 million hectares each year in China alone. Various types of cytoplasmic male sterility (CMS) and environment-conditioned genic male sterility (EGMS) systems have been applied in hybrid rice production. In this paper, recent advances in genetics, biochemistry, and molecular biology are reviewed with an emphasis on major male sterility systems in rice: five CMS systems, i.e., BT-, HL-, WA-, LD- and CW- CMS, and two EGMS systems, i.e., photoperiod- and temperature-sensitive genic male sterility (P/TGMS). The interaction of chimeric mitochondrial genes with nuclear genes causes CMS, which may be restored by restorer of fertility (Rf) genes. The PGMS, on the other hand, is conditioned by a non-coding RNA gene. A survey of the various CMS and EGMS lines used in hybrid rice production over the past three decades shows that the two-line system utilizing EGMS lines is playing a steadily larger role and TGMS lines predominate the current two-line system for hybrid rice production. The findings and experience gained during development and application of, and research on male sterility in rice not only advanced our understanding but also shed light on applications to other crops.

  1. Influence of plant species and environmental conditions on epiphytic and endophytic pink-pigmented facultative methylotrophic bacterial populations associated with field-grown rice cultivars.

    Science.gov (United States)

    Madhaiyan, Munusamy; Poonguzhali, Selvaraj; Sa, Tongmin

    2007-10-01

    The total methylotrophic population associated with rice plants from different cultivars was enumerated at three different stages: vegetative, flowering, and harvesting. The bacterial population in the leaf, rhizosphere soil, endophytic in the stem and roots, and epiphytic in the florets and grains were determined from four rice cultivars, Il-mi, Nam-pyeoung, O-dae, and Dong-jin, sampled from three different field sites. The methylotrophic bacteria isolated on AMS media containing 0.5% methanol as the sole carbon source uniformly showed three distinct morphologies, which were recorded as separate groups and their distribution among the various samples was determined using the ecophysiological index. The growth stage at the time of sampling had a more significant effect on the methylotrophic population and their distribution than the field site or cultivar. A similar effect was also observed for the PPFMs, where their population in different plant parts increased from V10 to R4 and then decreased towards stage R9. A canonical discriminant analysis of the PPFM population from different parts of rice showed clear variations among the cultivars, sampled sites, and growth stages, although the variations were more prominent among the growth stages.

  2. (Lilium) cultivar

    African Journals Online (AJOL)

    Yomi

    2012-08-30

    Aug 30, 2012 ... 2National Engineering Research Center for Floriculture, Beijing, China. Accepted 6 August, 2012 ... hybrids lily cultivar 'eyeliner' was selected as the materials. By using the ... of sterilization was not ideal which led to higher.

  3. Polyamine biosynthesis in rice cultivars under salt stress and comparison with observations under drought stress

    Directory of Open Access Journals (Sweden)

    Phuc Thi Do

    2014-05-01

    Full Text Available Soil salinity affects a large proportion of rural area and limits agricultural productivity. To investigate differential adaptation to soil salinity, we studied salt tolerance of 18 varieties of Oryza sativa using a hydroponic culture system. Based on visual inspection and photosynthetic parameters, cultivars were classified according to their tolerance level. Additionally, biomass parameters were correlated with salt tolerance. Polyamines have frequently been demonstrated to be involved in plant stress responses and therefore soluble leaf polyamines were measured. Under salinity, putrescine (Put content was unchanged or increased in tolerant, while dropped in sensitive cultivars. Spermidine (Spd content was unchanged at lower NaCl concentrations in all, while reduced at 100 mM NaCl in sensitive cultivars. Spermine (Spm content was increased in all cultivars. A comparison with data from 21 cultivars under long-term, moderate drought stress revealed an increase of Spm under both stress conditions. While Spm became the most prominent polyamine under drought, levels of all three polyamines were relatively similar under salt stress. Put levels were reduced under both, drought and salt stress, while changes in Spd were different under drought (decrease or salt (unchanged conditions. Regulation of polyamine metabolism at the transcript level during exposure to salinity was studied for genes encoding enzymes involved in the biosynthesis of polyamines and compared to expression under drought stress. Based on expression profiles, investigated genes were divided into generally stress-induced genes (ADC2, SPD/SPM2, SPD/SPM3, one generally stress-repressed gene (ADC1, constitutively expressed genes (CPA1, CPA2, CPA4, SAMDC1, SPD/SPM1, specifically drought-induced genes (SAMDC2, AIH, one specifically drought-repressed gene (CPA3 and one specifically salt-stress repressed gene (SAMDC4, revealing both overlapping and specific stress responses under these

  4. Allelopathy of weed extracts on yield and its components in four cultivars of rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Ali MOHADESI

    2011-07-01

    Full Text Available Weeds are enemies to the crop plants and have harmful effects on agricultural crops due to several factors such as competition for space, light and nutrients. Allelopathic effects of weed extracts were studied on grain yield and yield components of rice. The experiment was carried out in the Rice Research Institute of Chaparsar, in 2006- 2007, in Tonekabon, Iran (latitude 36°54’ N, longitude 50° 40’E, level -20 m altitude, split plot on basis of randomized completely block design (RCBD with 4 replications. Results showed highly significant differences suggesting substantial to moderate phenotypic variability in most parameters evaluated except number of empty grain and 1000 -grain weight. Also, most yield of single plant obtained from umbrella sedge extract (28.5 g. It seems that umbrella sedge had least minerals in water; it could be affected positively on important factors such as yield of single plant compared to other treatments. Correlation coefficient analysis revealed significant and negative correlation between number of empty grain and yield of single plant (r=-0.42***. It’s implies that grain yield magnitude of Nemat cultivar exhibiting the least number of empty grain. Although yield of single plant was not affected neither by plant height nor number of tiller. In addition, irrigation water due to existence of high mineral and chemical pesticides in upstream of station farms severely was reduced yield. Also, results of this research showed that weed extracts haven’t very allelopathic effect on rice and in end of growing season, that’s better, plant leftover return and remain in field.

  5. Effects of water management on arsenic and cadmium speciation and accumulation in an upland rice cultivar.

    Science.gov (United States)

    Hu, Pengjie; Ouyang, Younan; Wu, Longhua; Shen, Libo; Luo, Yongming; Christie, Peter

    2015-01-01

    Pot and field experiments were conducted to investigate the effects of water regimes on the speciation and accumulation of arsenic (As) and cadmium (Cd) in Brazilian upland rice growing in soils polluted with both As and Cd. In the pot experiment constant and intermittent flooding treatments gave 3-16 times higher As concentrations in soil solution than did aerobic conditions but Cd showed the opposite trend. Compared to arsenate, there were more marked changes in the arsenite concentrations in the soil solution as water management shifted, and therefore arsenite concentrations dominated the As speciation and bioavailability in the soil. In the field experiment As concentrations in the rice grains increased from 0.14 to 0.21 mg/kg while Cd concentrations decreased from 0.21 to 0.02 mg/kg with increasing irrigation ranging from aerobic to constantly flooding conditions. Among the various water regimes the conventional irrigation treatment produced the highest rice grain yield of 6.29 tons/ha. The As speciation analysis reveals that the accumulation of dimethylarsinic acid (from 11.3% to 61.7%) made a greater contribution to the increase in total As in brown rice in the intermittent and constant flooding treatments compared to the intermittent-aerobic treatment. Thus, water management exerted opposite effects on Cd and As speciation and bioavailability in the soil and consequently on their accumulation in the upland rice. Special care is required when irrigation regime methods are employed to mitigate the accumulation of metal(loid)s in the grain of rice grown in soils polluted with both As and Cd. Copyright © 2014. Published by Elsevier B.V.

  6. sativa L.) Cultivars

    African Journals Online (AJOL)

    Abstract. Ten rice cultivars from the International Rice Germplasm Centre originating from Bangladesh were analysedfor the~r genetics of resistance to bacterial blight. The test cultivars were selected on the basis of their high level ofresistance to races IV & VI ofXanthomonas oryzae pv. oryzae. The mode ofinheri- tance was ...

  7. Rice root-associated bacteria: insights into community structures across 10 cultivars

    NARCIS (Netherlands)

    Hardoim, P.R.; Andreote, F.D.; Reinhold-Hurek, B.; Sessitsch, A.; Overbeek, van L.S.; Elsas, van J.D.

    2011-01-01

    In this study, the effects of plant genotype, soil type and nutrient use efficiency on the composition of different bacterial communities associated with rice roots were investigated. Thus, total bacteria, Alpha- and Betaproteobacteria, Pseudomonas and Actinobacteria were studied using PCR, followed

  8. Rice root-associated bacteria : insights into community structures across 10 cultivars

    NARCIS (Netherlands)

    Hardoim, P. R.; Andreote, F. D.; Reinhold-Hurek, B.; Sessitsch, A.; van Overbeek, L. S.; van Elsas, J. D.

    In this study, the effects of plant genotype, soil type and nutrient use efficiency on the composition of different bacterial communities associated with rice roots were investigated. Thus, total bacteria, Alpha- and Betaproteobacteria, Pseudomonas and Actinobacteria were studied using PCR, followed

  9. Genetic parameters estimation on functional dryness traits of crossed black paddy rice "Baas Selem Cultivar X Situ Patenggang” variety

    Directory of Open Access Journals (Sweden)

    I.G.P.M. Aryana

    2014-07-01

    Full Text Available The aims of this study were to elucidate heritability and the role of drought traits genes of black paddy rice for determination base of the selection method to obtain drought tolerant and high yield potential of black paddy rice. The study was conducted through two experiments during February-November 2013. The first experiment was the establishment of populations from crosses carried out in the hybridization room. The second trial was evaluation of the genetic diversity of drought properties held in the greenhouse of the Faculty of Agriculture, University of Mataram. Planting was carried out in pots without experiment design. Population of P1 (parental-Situ Patenggang, P2 (parental-Baas Selem were 50 plants of each; population of F1, F1BC.1.2, and F1BC.1.1 were 25 plants of each, and 250 plants of F2, as well as control of drought susceptible variety (IR20 was 10 plants. To determine the heritability and the role of genes controlling drought traits were used index of bud dry and cure of IRRI standard. The results showed that crossing of black paddy rice "Baas Selem x Situ Patenggang” had relatively moderate heritability in broad sense and low heritability in narrow sense. In the crossed F1 population was found that gene action of drought trait was not perfectly dominant

  10. Blast resistance of space-induced variants derived from rice cultivar Hanghui 7

    International Nuclear Information System (INIS)

    Zhang Jingxin; Yang Qiyun; Zhu Xiaoyuan; Wang Hui; Zeng Liexian; Liu Yongzhu; Guo Tao; Chen Zhiqiang

    2010-01-01

    To screen the resistance lines to rice blast, the blast resistance of SP 3 and SP 4 progenies derived from rice variety Hanghui 7 were evaluated after satellite flight, and the genomic DNA polymorphism of the resistant variants selected from SP 3 was compared with the wild type by microsatellite markers. The results indicated that the SP 3 Variant line H24, which was selected from the 250 space-induced lines ( SP 3 ) with excellent agronomic and economical characters, showed resistance segregation (119R : 108S) against blast isolate GD3286. It was demonstrated that the resistance of H24 might be controlled by two dominant and complementary resistance genes. The resistance of H24 was still segregated in SP 4 , but the resistance spectrum of H24 was 84. 4% in SP 5 , much higher than the wild type, 40. 6%, and H24 especially showed resistant against some blast isolates of broad pathogenic spectrum or specialized pathogenicity; further more, the DNA polymorphism wasn't detected between H24 and its wild type by 229 SSR (simple sequence repeat) markers covering the rice genome equally. (authors)

  11. Fine definition of the pedigree haplotypes of closely related rice cultivars by means of genome-wide discovery of single-nucleotide polymorphisms.

    Science.gov (United States)

    Yamamoto, Toshio; Nagasaki, Hideki; Yonemaru, Jun-ichi; Ebana, Kaworu; Nakajima, Maiko; Shibaya, Taeko; Yano, Masahiro

    2010-04-27

    To create useful gene combinations in crop breeding, it is necessary to clarify the dynamics of the genome composition created by breeding practices. A large quantity of single-nucleotide polymorphism (SNP) data is required to permit discrimination of chromosome segments among modern cultivars, which are genetically related. Here, we used a high-throughput sequencer to conduct whole-genome sequencing of an elite Japanese rice cultivar, Koshihikari, which is closely related to Nipponbare, whose genome sequencing has been completed. Then we designed a high-throughput typing array based on the SNP information by comparison of the two sequences. Finally, we applied this array to analyze historical representative rice cultivars to understand the dynamics of their genome composition. The total 5.89-Gb sequence for Koshihikari, equivalent to 15.7 x the entire rice genome, was mapped using the Pseudomolecules 4.0 database for Nipponbare. The resultant Koshihikari genome sequence corresponded to 80.1% of the Nipponbare sequence and led to the identification of 67,051 SNPs. A high-throughput typing array consisting of 1917 SNP sites distributed throughout the genome was designed to genotype 151 representative Japanese cultivars that have been grown during the past 150 years. We could identify the ancestral origin of the pedigree haplotypes in 60.9% of the Koshihikari genome and 18 consensus haplotype blocks which are inherited from traditional landraces to current improved varieties. Moreover, it was predicted that modern breeding practices have generally decreased genetic diversity Detection of genome-wide SNPs by both high-throughput sequencer and typing array made it possible to evaluate genomic composition of genetically related rice varieties. With the aid of their pedigree information, we clarified the dynamics of chromosome recombination during the historical rice breeding process. We also found several genomic regions decreasing genetic diversity which might be

  12. Accumulation of weathered p,p'-DDTs in hybridized Cucurbita pepo cultivars.

    Science.gov (United States)

    Isleyen, Mehmet; Sevim, Pinar; White, Jason C

    2012-08-01

    Cucurbita pepo spp pepo (zucchini) is known as an exceptional weathered dichlorodiphenyldichloroethylene (DDE) accumulator, whereas Cucurbita pepo ssp ovifera (squash) is termed a nonaccumulator. Experiments were conducted with hybridized zucchini and squash to assess the inheritance pattern of DDX (the sum of p,p'-dichlorodiphenyltrichloroethane [p,p'-DDT], p,p'-dichlorodiphenyldichloroethane [p,p'-DDD], and p,p'-dichlorodiphenyldichloroethylene [p,p'-DDE]) accumulation potential in xylem sap and tissues of parental, F1 hybrids, and F1 backcross (BC) generations of plants. Plants were grown in pots containing soil with weathered DDX at 732 to 1,130 ng/g soil or under field conditions in soil with 322 to 2,700 ng/g. The DDX stem bioconcentration factors and xylem sap values showed differences between parental and hybridized plants of squash and zucchini. For squash grown in greenhouse conditions, the DDX flow rate in the xylem sap was 17.3, 121, and 40.8 ng/h in parental, F1 hybrids, and F1 BC plants, respectively. Similarly, the stem DDX content of parental, F1, and F1 BC squash was 11, 253, and 96 ng/g (dry wt), respectively. A similar inheritance pattern for squash was observed when the plants were grown under field conditions. The DDX flow rates in the xylem sap of pot-grown parental, F1, and F1 BC zucchini cultivars were 100, 8.5, and 26 ng/hr, respectively, and the stem DDX content was 191, 102, and 142 ng/g, respectively. Again, similar trends in accumulation potential were observed for hybridized zucchini grown under field conditions. The DDX concentrations in parental plants matched the expected pattern, with hybrids midway between the two species, and the backcross being more like the parent again for both species. This inheritance pattern of contaminant accumulation and translocation ability follows classical Mendelian segregation and suggests single-gene or single-locus control. Copyright © 2012 SETAC.

  13. Changes of tocopherols, tocotrienols, γ-oryzanol, and γ-aminobutyric acid levels in the germinated brown rice of pigmented and nonpigmented cultivars.

    Science.gov (United States)

    Ng, Lean-Teik; Huang, Shao-Hua; Chen, Yen-Ting; Su, Chun-Han

    2013-12-26

    This study examined the changes of tocopherols (Toc), tocotrienols (T3), γ-oryzanol (GO), and γ-aminobutyric acid (GABA) contents in germinated brown rice (GBR) of pigmented and nonpigmented cultivars under different germination conditions. Results showed that the Toc and T3 contents in GBR were significantly different between treatments in both rice cultivars. The pigmented GBR possessed higher total vitamin E, total Toc, total T3, and GO contents than the nonpigmented GBR; however, its level of GABA was lower. The order of the three highest vitamin E homologues in pigmented and nonpigmented GBR was γ-T3 > γ-Toc > α-Toc and α-Toc > γ-T3 > α-T3, respectively; β-Toc, β-T3, δ-Toc, and δ-T3 were present in only small amounts (≤1.0 mg/kg) in GBR of both cultivars. Although both cultivars showed an increase in GABA contents with increasing germination time, the GABA content in nonpigmented GBR was higher.

  14. Crescimento radicular e aéreo de cultivares de arroz de terras altas em função da calagem Root and shoot growth of upland rice cultivars as affected by lime application

    Directory of Open Access Journals (Sweden)

    Carlos Alexandre Costa Crusciol

    2012-01-01

    Full Text Available O presente trabalho teve como objetivo avaliar o crescimento radicular e da parte aérea, além da eficiência de absorção de nutrientes pelas cultivares de arroz Caiapó e Maravilha, em função da calagem. O experimento foi desenvolvido em casa de vegetação, sendo os tratamentos constituídos pelas cultivares Caiapó e Maravilha combinadas com os índices de saturação por bases (V% de 10, 40 e 70. O delineamento experimental utilizado foi inteiramente casualizado, com quatro repetições. Foram avaliados o número de perfilhos, comprimento radicular, matéria seca de raízes, folhas e colmos, o teor foliar e a eficiência de absorção dos macronutrientes. De forma geral, observou-se que a cultivar moderna superou a tradicional em matéria seca de raízes, comprimento radicular, número de colmos, matéria seca de colmos e da parte aérea, além de acumular mais nutrientes a cultivar tradicional, mesmo nas condições de maior acidez. No entanto, os teores de nutrientes foram maiores na cultivar Caiapó. A cultivar Maravilha possui maior crescimento radicular e da parte aérea, nos diversos níveis de acidez, enquanto a Caiapó tem maior eficiência de absorção dos nutrientes do solo. A V% de 40 é a mais efetiva para ambas as cultivares.This work aimed to evaluate root growth, shoot development and nutrient absorption efficiency by rice cultivars Caiapó and Maravilha as affected by lime application. The experiment was carried out in a greenhouse, with treatments set up by Caiapó and Maravilha cultivars in combination with the base saturation (V% of 10%, 40% and 70%. The experiment was in a randomized complete block design, with four replications. The number of tillers, root length, root dry matter, leaves and stems, leaf content and macronutrients absorption efficiency were evaluated. Comparing cultivars, Maravilha cultivar presented higher root dry weight, root length, number of stems, dry matter of stems and shoot than Caiap

  15. Testing of Rice Stocks for Their Survival of Winter Cold

    Directory of Open Access Journals (Sweden)

    Hiroshi Ikehashi

    2018-03-01

    Full Text Available Rice cultivation is considered to be initiated by vegetative propagation of sprout from wild perennial stocks. To test whether any presently cultivated rice cultivar can survive the winter cold or not, rice stocks of several cultivars including indica and japonica types were placed in a shallow pool from October to April in 2015–2016 and 2016–2017. During the coldest period of the winter, the bases of the stocks were placed 5–6 cm below the surface of water, where temperatures ranged from 3 °C to 5 °C, while the surface was frozen for two or three times and covered with snow for a day. Only one cultivar, Nipponbare, a japonica type, survived the winter cold and regenerated sprouts in the end of April or early May. A possibility to develop perennial cultivation of rice or perennial hybrid rice is discussed.

  16. Sweet sorghum performance under irrigated conditions in northwest China : Biomass and its partitioning in inbred and hybrid cultivars at two nitrogen levels

    NARCIS (Netherlands)

    Fan, F.; Spiertz, J.H.J.; Han, L.P.; Liu, Z.X.; Xie, G.H.

    2013-01-01

    Effects of cultivar choice and nitrogen supply on biomass yield and dry matter partitioning of sweet sorghum [Sorghum bicolor (L.) Moench] were studied under irrigated conditions in the arid temperate climate of north-west China. Two hybrid cultivars, Zaoshu-1 (ZS 1) and Chuntian-2 (CT 2), and two

  17. Identification of a new locus conferring antixenosis to the brown planthopper in rice cultivar Swarnalata (Oryza sativa L.).

    Science.gov (United States)

    Qiu, Y F; Cheng, L; Liu, F; Li, R B

    2013-08-29

    The brown planthopper [Nilaparvata lugens (Stål); BPH] has caused severe damage to rice production. The identification of resistance genes and the development of BPH-resistant varieties are economical and effective ways to manage this pest. Using an F2 population from a cross between the Indica cultivars 93-11 and Swarnalata, we mapped the Qbph-8 locus to a 7.3-cM region on chromosome 8 in two tests, flanked by the markers RM339 and RM515. In this population, Qbph-8 explained 7.7 and 6.6% of the phenotypic variance of BPH preference in both tests. In the BPH host choice test, the average number of settled BPHs on the Qbph-8 plants was less than that on the 93-11 plants over the 24- to 120-h observation period. Furthermore, less BPH insects were observed on the BPH6+Qbph-8 plant compared with the BPH6 plant or Qbph-8 plant, indicating a stronger antixenotic effect shown in the gene pyramiding plants. Hence, this locus can be pyramided with other BPH resistance genes and applied to breed-resistant varieties, which possibly can improve the resistance level and durable resistance to the BPH.

  18. Meiotic analysis and FISH with rDNA and rice BAC probes of the Thai KPS 01-01-25 sugarcane cultivar

    NARCIS (Netherlands)

    Thumjamras, Sarut; Iamtham, Siriluck; Prammanee, Siripatr; Jong, de Hans

    2016-01-01

    The interspecific sugarcane hybrid “KPS 01-01-25” is one of Thailand’s most successful cultivars, but its genetics and genomic constitution are greatly complicated due to the highly polyploid nature of this crop. Here we analyzed the crop’s karyotype, studied chromosome pairing at meiosis I and

  19. Enzyme expression in indica and japonica rice cultivars under saline stress - doi: 10.4025/actascibiolsci.v34i4.8535

    Directory of Open Access Journals (Sweden)

    Luciano do Amarante

    2012-09-01

    Full Text Available The southern State of Rio Grande do Sul (RS is the main rice producer in Brazil with a 60% participation of the national production and 86% participation of the region. Rice culture irrigation system is done by flooding, which leads to soil salinization, a major environmental constraint to production since it alters the plants’ metabolism exposed to this type of stress. The indica cultivar, widely used in RS, has a higher sensitivity to salinity when compared to that of the japonica cultivar in other physiological aspects. Current research analyzes enzymes expression involved in salt-subjected indica and japonica rice cultivars’ respiration. Oryza sativa L. spp. japonica S.Kato (BRS Bojuru, IAS 12-9 Formosa and Goyakuman and Oryza sativa L. spp. indica S. Kato (BRS Taim-7, BRS Atalanta and BRS Querencia were the cultivars employed. Seedlings were transferred to 15 L basins containing 50% Hoagland nutrient solution increased by 0, 25, 50, 75 and 100 mM NaCl, and collected at 14, 28 and 42 days after transfer (DAT. Plant tissues were macerated and placed in eppendorf tubes with Scandálios extractor solution. Electrophoresis was performed in 7% of the polyacrylamide gels in vertical vats. Bands were revealed for the following enzymes systems: esterase, alcohol dehydrogenase, phosphoglucoisomerase, malate dehydrogenase, malic enzyme and alpha amylase. The enzymes expression was greater in subspecies japonica, with more intense bands in proportion to salinity increase. Results show that enzyme systems are involved in the salinity defense mechanisms in O. sativa spp. japonica cultivar.  

  20. Differential activation of genes related to aluminium tolerance in two contrasting rice cultivars.

    Science.gov (United States)

    Roselló, Maite; Poschenrieder, Charlotte; Gunsé, Benet; Barceló, Juan; Llugany, Mercè

    2015-11-01

    Rice (Oryza sativa) is a highly Al-tolerant crop. Among other mechanisms, a higher expression of STAR1/STAR2 (sensitive to Al rhizotoxicity1/2) genes and of Nrat1 (NRAMP Aluminium Transporter 1), and ALS1 (Aluminium sensitive 1) can at least in part be responsible for the inducible Al tolerance in this species. Here we analysed the responses to Al in two contrasting rice varieties. All analysed toxicity/tolerance markers (root elongation, Evans blue, morin and haematoxylin staining) indicated higher Al-tolerance in variety Nipponbare, than in variety Modan. Nipponbare accumulated much less Al in the roots than Modan. Aluminium supply caused stronger expression of STAR1 in Nipponbare than in Modan. A distinctively higher increase of Al-induced abscisic acid (ABA) accumulation was found in the roots of Nipponbare than in Modan. Highest ABA levels were observed in Nipponbare after 48 h exposure to Al. This ABA peak was coincident in time with the highest expression level of STAR1. It is proposed that ABA may be required for cell wall remodulation facilitated by the enhanced UDP-glucose transport to the walls through STAR1/STAR2. Contrastingly, in the roots of Modan the expression of both Nrat1 coding for a plasma membrane Al-transporter and of ALS1 coding for a tonoplast-localized Al transporter was considerably enhanced. Moreover, Modan had a higher Al-induced expression of ASR1 a gene that has been proposed to code for a reactive oxygen scavenging protein. In conclusion, the Al-exclusion strategy of Nipponbare, at least in part mediated by STAR1 and probably regulated by ABA, provided better protection against Al toxicity than the accumulation and internal detoxification strategy of Modan mediated by Nrat1, ALS1 and ARS1. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Thoughts and Practice on Some Problems about Research and Application of Two-Line Hybrid Rice

    Directory of Open Access Journals (Sweden)

    Li-yun CHEN

    2011-06-01

    Full Text Available The main problems about research and application of two-line hybrid rice were reviewed, including the confusing nomenclature and male sterile lines classification, the unclear characteristics of photoperiod and temperature responses and the unsuitable site selection for male sterile line and hybrid rice seed production. In order to efficiently and accurately use dual-purpose genic male sterile lines, four types, including PTGMS (photo-thermo-sensitive genic male sterile rice, TGMS (thermo-sensitive genic male sterile rice, reverse PTGMS and reverse TGMS, were proposed. A new idea for explaining the mechanism of sterility in dual-purpose hybrid rice was proposed. The transition from sterile to fertile was involved in the cooperative regulation of major-effect sterile genes and photoperiod and/or temperature sensitive ones. The minor-effect genes with accumulative effect on sterility were important factors that affected the critical temperature of sterility transfer. In order to make better use of dual-purpose lines, the characterization of responses to photoperiod and temperature of PTGMS should be made and the identification method for the characterization of photoperiod and temperature responses of PTGMS should also be put forward. The optimal ecological site for seed production could be determined according to the historical climate data and the requirements for the meteorological conditions during the different periods of seed production.

  2. Genetics and Improvement of Bacterial Blight Resistance of Hybrid Rice in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qi

    2009-01-01

    Since 1980s, rice breeding for resistance to bacterial blight has been rapidly progressing in China. The gene Xa4 was mainly used in three-line indica hybrid and two-line hybrid rice. The disease has been 'quiet' for 20 years in China, yet in recent years it has gradually emerged and been prevalent in fields planted with newly released rice varieties in the Changjiang River valley. Under the circumstances, scientists inevitably raised several questions: what causes the resurgence and what should we do next? And/or is resistance breeding still one of the main objectives in rice improvement? Which approach do we take on resistance breeding so that the resistance will be more durable, and the resistance gene will be used more efficiently? A combined strategy involving traditional method, molecular marker-assisted selection, and transgenic technology should bring a new era to the bacterial blight resistance hybrid rice breeding program. This review also briefly discusses and deliberates on issues related to the broadening of bacterial blight resistance, and suitable utilization of resistance genes, alternate planting of available resistance genes; and understands the virulent populations of the bacterial pathogen in China even in Asia.

  3. Identification of rice hybrids using microsatellite and RAPD markers

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    May 18, 2009 ... presence of slower migrating heteroduplex DNA is, there- fore, useful for detection of heterozygous individuals. Maintenance of hybrid seeds conformity in high level is essential for exploitation of hybrid vigor. Therefore, test- ing the hybrid seed purity is necessarily required before its release into the market.

  4. Comparison of NH4+-N and NO3--N nutrition in hybrid and conventional rice at the late growth stage

    International Nuclear Information System (INIS)

    Yang Xiaoe; Sun Xi

    1990-01-01

    The difference of NH 4 + -N/NO 3 - -N nutrition between hybrid and conventional rice varieties at the late growth stage was studied by using 15 N-tracer technique. The results showed that the nitrate fertilizer utilization efficiency by the hybrid rice after anthesis was 7.8% higher than that by the ordinary rice variety, and the nitrate fertilizer recovery fraction by the former was 13.2% greater than that by the latter. The varietal difference in NO 3 - -N uptake and utilization was almost twice as that in NH 4 + -N. It was also showed that 15 N distribution in ear of the hybrid rice was about 20% greater than that of the conventional variety, but there were no obvious differences between NO 3 - -N and NH 4 + -N. However, 15 N distribution in the lower node leaves and root was found to be significant higher with NO 3 - -N than that with NH 4 + -N in both rice varieties, particularly in the hybrid rice. Compared with NH 4 + -N, NO 3 - -N top-dressing before anthesis was observed to have much greater positive effects on the uptake of calcium and magnesium and the growth of the superficial root and the grain yield of the tested rice varieties, especially of the hybrid rice

  5. Transgene Flow from Glufosinate-Resistant Rice to Improved and Weedy Rice in China

    Directory of Open Access Journals (Sweden)

    Yong-liang LU

    2014-09-01

    Full Text Available The development of transgenic rice with novel traits in China can increase rice productivity, but transgene flow to improved or weedy rice has become a major concern. We aimed to evaluate the potential maximum frequencies of transgene flow from glufosinate-resistant rice to improved rice cultivars and weedy rice. Treatments were arranged in randomized complete blocks with three replicates. Experiments were conducted between 2009 and 2010 at the Center for Environmental Safety Supervision and Inspection for Genetically Modified Plants, China National Rice Research Institute, Hangzhou, China. Glufosinate-resistant japonica rice 99-1 was the pollen donor. The pollen recipients were two inbred japonica rice (Chunjiang 016 and Xiushui 09, two inbred indica rice (Zhongzu 14 and Zhongzao 22, two indica hybrid rice (Zhongzheyou 1 and Guodao 1, and one weedy indica rice (Taizhou weedy rice. The offspring of recipients were planted in the field and sprayed with a commercial dose of glufosinate. Leaf tissues of survivors were analyzed by polymerase chain reaction to detect the presence of the transgene. The frequency of gene flow ranged from 0 to 0.488%. In 2009, the order of gene flow frequency was as follows: weedy rice > Chunjiang 016 > Xiushui 09 and Zhongzu 14 > Guodao 1, Zhongzheyou 1 and Zhongzao 22. Gene flow frequencies were generally higher in 2009 than in 2010, but did not differ significantly among rice materials. Gene flow frequency was the highest in weedy rice followed by the inbred japonica rice. The risk of gene flow differed significantly between years and year-to-year variance could mask risk differences among pollen recipients. Gene flow was generally lesser in taller pollen recipients than in shorter ones, but plant height only accounted for about 30% of variation in gene flow. When flowering synchrony was maximized, as in this study, low frequencies of gene flow occurred from herbicide-resistant japonica rice to other cultivars and

  6. Forage growth, yield and quality responses of Napier hybrid grass cultivars to three cutting intervals in the Himalayan foothills

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    Kesang Wangchuk

    2015-09-01

    Full Text Available A 3 x 3 factorial study was conducted in the southern foothills of Bhutan to compare 3 cultivars of Napier hybrid grass (Pennisetum purpureum x P. glaucum: Pakchong-1, CO-3 and Giant Napier, at 3 cutting intervals (40, 60 and 80 days, in terms of forage growth, dry matter (DM yield and crude protein (CP concentration. The effects of cultivar x cutting interval were significant only on tiller number per plant and leaf:stem ratio (LSR. CO-3 consistently produced the highest tiller number per plant, leaves per plant and LSR, while Pakchong-1 produced the lowest. Pakchong-1 plants were taller, had bigger tillers and basal circumference and higher stem DM production than CO-3 and Giant. Leaf CP for all cultivars was about 17%, while stem CP concentration was lower for Pakchong-1 than for the other cultivars (3.6 vs. 5.3%, P<0.05. While 40-day cutting intervals produced high quality forage, yields suffered marked-ly and the best compromise between yield and quality of forage seemed to occur with 60-day cutting intervals. Pakchong-1 seems to have no marked advantages over CO-3 and Giant for livestock feed, and feeding studies would verify this. Its higher stem DM yields may be advantageous for biogas production and this aspect should be investigated.Keywords: Bhutan, CO-3, crude protein , dry matter, Giant Napier, Pakchong-1.DOI: 10.17138/TGFT(3142-150

  7. Overcoming inter-subspecific hybrid sterility in rice by developing indica-compatible japonica lines.

    Science.gov (United States)

    Guo, Jie; Xu, Xiaomei; Li, Wentao; Zhu, Wenyin; Zhu, Haitao; Liu, Ziqiang; Luan, Xin; Dai, Ziju; Liu, Guifu; Zhang, Zemin; Zeng, Ruizhen; Tang, Guang; Fu, Xuelin; Wang, Shaokui; Zhang, Guiquan

    2016-06-01

    Rice (Oryza sativa L.) is an important staple crop. The exploitation of the great heterosis that exists in the inter-subspecific crosses between the indica and japonica rice has long been considered as a promising way to increase the yield potential. However, the male and female sterility frequently occurred in the inter-subspecific hybrids hampered the utilization of the heterosis. Here we report that the inter-subspecific hybrid sterility in rice is mainly affected by the genes at Sb, Sc, Sd and Se loci for F1 male sterility and the gene at S5 locus for F1 female sterility. The indica-compatible japonica lines (ICJLs) developed by pyramiding the indica allele (S-i) at Sb, Sc, Sd and Se loci and the neutral allele (S-n) at S5 locus in japonica genetic background through marker-assisted selection are compatible with indica rice in pollen fertility and in spikelet fertility. These results showed a great promise of overcoming the inter-subspecific hybrid sterility and exploiting the heterosis by developing ICJLs.

  8. Physiological analysis of leaf senescence of two rice cultivars with different yield potential Análise fisiológica da senescência foliar de duas cultivares de arroz com diferentes potenciais de produtividade

    Directory of Open Access Journals (Sweden)

    Antelmo Ralph Falqueto

    2009-07-01

    Full Text Available The objective of this work was to evaluate the physiological changes that occur in different leaves during the early and late grain-filling stages of two rice genotypes (Oryza sativa subsp. indica , BRS Pelota cultivar, and O. sativa subsp. japonica , BRS Firmeza cultivar, which present differences in grain yield potential. The plants were cultivated in greenhouse. Pigment content, chlorophyll fluorescence, electron transport and oxygen evolution rate were determined in the grain-filling stage, from the first to the forth leaf (top to bottom. Pigment content, photochemical efficiency of photosystem II and electron transport decreased significantly according to the position of leaves in 'BRS Pelota'. The BRS Firmeza cultivar shows higher pigment content and higher activity of the photosynthetic apparatus in comparison to 'BRS Pelota' during the grain-filling stage.O objetivo deste trabalho foi avaliar as mudanças fisiológicas que ocorrem em diferentes folhas durante o início e o final do estádio de enchimento de grãos em dois genótipos de arroz (Oryza sativa subsp. indica cultivar BRS Pelota e O. sativa subsp. japonica cultivar BRS Firmeza que apresentam diferenças no potencial de produção de grãos. As plantas foram cultivadas em casa de vegetação. Os teores de pigmentos, a fluorescência da clorofila e a taxa de liberação de oxigênio foram determinados no estádio de enchimento de grão da primeira à quarta folha (do topo à base. O teor de pigmentos, a eficiência fotoquímica do fotossistema II e o transporte de elétrons decresceram significativamente de acordo com a posição das folhas na cultivar BRS Pelota. A cultivar BRS Firmeza apresentou maior teor de pigmentos e maior atividade do aparato fotossintético em comparação à 'BRS Pelota' durante o estádio de enchimento de grão.

  9. Acúmulo de massa seca em três cultivares de arroz irrigado com diferentes arquiteturas de plantas Dry matter accumulation by three flooded rice cultivars with different plant canopy

    Directory of Open Access Journals (Sweden)

    Juçara Terezinha Paranhos

    1995-01-01

    Full Text Available O experimento foi conduzido em Planossolo da Unidade de Mapeamento Vacacaí, com o ohjetivo de estudar o acúmulo de massa seca nos diversos órgãos da planta de três cultivares de arroz irrigado (EEA 406, Bluebelle e BR-IRGA 409, utilizando-se delineamento de blocos ao acaso com cinco repetições. A massa seca foi obtida em sete estádios fenológicos da cultura. Desconsiderando os grãos e panículas, a EEA 406 possui maior capacidade produtiva de fitomassa, sendo a Bluebelle menos produtiva. Na maturação, a cultivar BR-IRGA 409 apresentou maior massa seca total, demonstrando maior capacidade de alocar assimilados nos grãos e maior eficiência de conversão de energia solar em fitomassa, sendo a Bluebelle menos eficiente. Para as três cultivares, até a floração, o colmo acumulou a maior percentagem de massa seca sendo, a partir daí, substituído pelas panículas e grãos. O máximo acúmulo de massa seca nas raízes ocorreu por ocasião da floração, cerca de 80 dias após a emergência.This experiment was carried out in an Halbaqualf soil to study the dry matter accumulation of three flooded rice cultivars. A complete randomized block design was used, with tive replication. Plant dry matter was measured in seven different growth stages. The cultivar EEA 406 had a higherdry matter accumulation than the cultivar Bluebelle without including grain and panicle. At maturity, the BR-IRGA 409 cultivar showed higher total dry matter. This demonstrate a better capacity of this variety in alocating assimilates into grains a higher effíciency in converting solar energy into plant biomass. The Bluebelle had lower efficiency. The dry matter accumulation increased for the three varieties from seeding to flowering into colm and, from flowering to harvest into panicles and grain. The maximum dry matter accumulation in roots was observed at flowering, eighty days after emergency.

  10. Application of gamma-ray irradiation technique to select, create and develop super rice with high quality to substitute the imported hybrid rice

    International Nuclear Information System (INIS)

    Tran Duy Quy; Tran Duy Vuong; Tran Duy Duong; Bui Huy Thuc

    2015-01-01

    Three varieties NPT3, BQ and TQ14 were selected by irradiation ray source Gamma Co-60 with dry seed, 13% grain moisture and created at 25-30 krad. NPT3 is super rice varieties with characteristics such as: extremely short growing period (105-110 day crop; 130- 135 days in the spring, the average yield of 9-10 tones/ha), quality, stem, leaf stand, suitable for intensive capability, able to resist pests and unfavorable conditions especially the elements of productivity (amylase from 15-16%) and mass produced including hybrid rice as Nhi Uu 868, Thien Nguyen Uu 9, HYT100, etc. BQ rice varieties were high quality, average productivity gain of 7.5- 8.0 ton/ha, equivalent to hybrid rice, short growth period (105-110 days in summer season; 120- 130 days in spring season), and quality rice: content 18-20% amylose, rice delicious, supple as BC15. TQ14 varieties was planted in 2 seasons/ year, with agricultural and biological characteristics as Khang-Dan18 mutant with wide adaptation, high yield potential, the average gain from 5.9 to 6.2 tones/ha, short growth period (105-110 days in summer season, 130-135 days in spring season), insect resistance, quality of rice suitable for manufacturing technology like noodles, instant noodles, rice noodles, Ethanol. (author)

  11. Mapping and pyramiding of two major genes for resistance to the brown planthopper (Nilaparvata lugens [Stål]) in the rice cultivar ADR52.

    Science.gov (United States)

    Myint, Khin Khin Marlar; Fujita, Daisuke; Matsumura, Masaya; Sonoda, Tomohiro; Yoshimura, Atsushi; Yasui, Hideshi

    2012-02-01

    The brown planthopper (BPH), Nilaparvata lugens (Stål), is one of the most serious and destructive pests of rice, and can be found throughout the rice-growing areas of Asia. To date, more than 24 major BPH-resistance genes have been reported in several Oryza sativa ssp. indica cultivars and wild relatives. Here, we report the genetic basis of the high level of BPH resistance derived from an Indian rice cultivar, ADR52, which was previously identified as resistant to the whitebacked planthopper (Sogatella furcifera [Horváth]). An F(2) population derived from a cross between ADR52 and a susceptible cultivar, Taichung 65 (T65), was used for quantitative trait locus (QTL) analysis. Antibiosis testing showed that multiple loci controlled the high level of BPH resistance in this F(2) population. Further linkage analysis using backcross populations resulted in the identification of BPH-resistance (antibiosis) gene loci from ADR52. BPH25 co-segregated with marker S00310 on the distal end of the short arm of chromosome 6, and BPH26 co-segregated with marker RM5479 on the long arm of chromosome 12. To characterize the virulence of the most recently migrated BPH strain in Japan, preliminary near-isogenic lines (pre-NILs) and a preliminary pyramided line (pre-PYL) carrying BPH25 and BPH26 were evaluated. Although both pre-NILs were susceptible to the virulent BPH strain, the pre-PYL exhibited a high level of resistance. The pyramiding of resistance genes is therefore likely to be effective for increasing the durability of resistance against the new virulent BPH strain in Japan.

  12. Relative resistance or susceptibility of maple (Acer) species, hybrids and cultivars to six arthropod pests of production nurseries.

    Science.gov (United States)

    Seagraves, Bonny L; Redmond, Carl T; Potter, Daniel A

    2013-01-01

    Maples (Acer spp.) in production nurseries are vulnerable to numerous arthropod pests that can stunt or even kill the young trees. Seventeen cultivars representing various Acer species and hybrids were evaluated for extent of infestation or injury by shoot and trunk borers (Proteoteras aesculana, Chrysobothris femorata), potato leafhopper (Empoasca fabae), Japanese beetle (Popillia japonica), maple spider mite (Oligonychus aceris) and calico scale (Eulecanium cerasorum). Evaluations were done in replicated field plots in central and western Kentucky. All of the maples were susceptible, to varying degrees, to one or more key pest(s). Red maples (A. rubrum) were relatively vulnerable to potato leafhopper injury and borers but nearly free of Japanese beetle feeding and spider mites. Sugar maples sustained conspicuous Japanese beetle damage but had very low mite populations, whereas the opposite was true for Freeman maples (A. × freemanii). A. campestre was heavily infested by calico scale. Within each species or hybrid there were cultivar differences in degree of infestation or damage by particular pests. The results should help growers to focus pest management efforts on those plantings at greatest risk from particular pests, and to choose cultivars requiring fewer insecticide inputs to produce a quality tree. Copyright © 2012 Society of Chemical Industry.

  13. Reduced arsenic accumulation in indica rice (Oryza sativa L.) cultivar with ferromanganese oxide impregnated biochar composites amendments.

    Science.gov (United States)

    Lin, Lina; Gao, Minling; Qiu, Weiwen; Wang, Di; Huang, Qing; Song, Zhengguo

    2017-12-01

    The effects of biochar (BC) and ferromanganese oxide biochar composites (FMBC 1 and FMBC 2 ) on As (Arsenic) accumulation in rice were determined using a pot experiment. Treatments with BC or FMBC improved the dry weights of rice roots, stems, leaves, and grains in soils containing different As contamination levels. Compared to BC treatment, FMBC treatments significantly reduced As accumulation in different parts of the rice plants (P rice can be attributed to As(III) to As(V) oxidation by ferro - manganese binary oxide, which increased the As adsorbed by FMBC. Furthermore, Fe and Mn plaques on the rice root surface decreased the transport of As in rice. Taken together, our results demonstrated the applicability of FMBC as a potential measure for reducing As accumulation in rice, improving the amino acid content of rice grains, and effectively remediating As-polluted soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Switchgrass cultivar EG1101

    Science.gov (United States)

    Bouton, Joseph H; Wood, Donald T

    2012-11-27

    A switchgrass cultivar designated EG1101 is disclosed. Also disclosed are seeds of switchgrass cultivar EG1101, plants of switchgrass EG1101, plant parts of switchgrass cultivar EG1101 and methods for producing a switchgrass plant produced by crossing switchgrass cultivar EG1101 with itself or with another switchgrass variety. Methods are also described for producing a switchgrass plant containing in its genetic material one or more transgenes and to the transgenic switchgrass plants and plant parts produced by those methods. Switchgrass cultivars or breeding cultivars and plant parts derived from switchgrass variety EG1101, methods for producing other switchgrass cultivars, lines or plant parts derived from switchgrass cultivar EG1101 and the switchgrass plants, varieties, and their parts derived from use of those methods are described herein. Hybrid switchgrass seeds, plants and plant parts produced by crossing the cultivar EG1101 with another switchgrass cultivar are also described.

  15. Switchgrass cultivar EG1102

    Science.gov (United States)

    Bouton, Joseph H; Wood, Donald T

    2012-11-20

    A switchgrass cultivar designated EG1102 is disclosed. The invention relates to the seeds of switchgrass cultivar EG1102, to the plants of switchgrass EG1102, to plant parts of switchgrass cultivar EG1102 and to methods for producing a switchgrass plant produced by crossing switchgrass cultivar EG1102 with itself or with another switchgrass variety. The invention also relates to methods for producing a switchgrass plant containing in its genetic material one or more transgenes and to the transgenic switchgrass plants and plant parts produced by those methods. This invention also relates to switchgrass cultivars or breeding cultivars and plant parts derived from switchgrass variety EG1102, to methods for producing other switchgrass cultivars, lines or plant parts derived from switchgrass cultivar EG1102 and to the switchgrass plants, varieties, and their parts derived from use of those methods. The invention further relates to hybrid switchgrass seeds, plants and plant parts produced by crossing the cultivar EG1102 with another switchgrass cultivar.

  16. A study on flexural and water absorption of surface modified rice husk flour/E-glass/polypropylene hybrid composite

    Science.gov (United States)

    Rassiah, K.; Sin, T. W.; Ismail, M. Z.

    2016-10-01

    This work is to study the effects of rice husk (RH)/E-Glass (EG)/polypropylene (PP) hybrid composites in terms of flexural and water absorption properties. The tests conducted are the flexural test and also the water absorption test using two types of water: distilled and sea water. The hybrid composites are prepared with various ratios of fibre weight fractions and the rice husk is treated using 2% Sodium Hydroxide (NaOH) to improve interaction and adhesion between the non-polar matrix and the polar lignocellulosic fibres. It was found that the content of rice husk/E-Glass fillers affected the structural integrity and flexural properties of hybrid composites. In addition, a higher ratio of rice husk contributes to higher water absorption in the hybrid composites.

  17. Tolerância de cultivares de arroz a diferentes níveis de alumínio em solução nutritiva Rice cultivars tolerance to different levels of aluminum in nutrient solution

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    Carlos Eduardo de Oliveira Camargo

    1983-01-01

    Full Text Available Em condições controladas de crescimento, foram estudados 22 cultivares de arroz, em soluções nutritivas com temperaturas de 25 ± 1°C e 30 ± 1°C, com cinco diferentes níveis de alumínio, em recipientes de 8,3 litros com 330 plântulas por recipiente. A tolerância foi medida pela capacidade de as raízes primárias continuar a crescer, em solução sem alumínio, após um período de 72 horas em solução contendo uma concentração conhecida de alumínio. Nas soluções nutritivas com temperatura de 25 ± 1°C, os cultivares IAC-899 e IR-841 foram sensíveis a 10mg/litro de Al3+; IR-43, IR-45 e IR-8, foram sensíveis a 20mg/litro de Al3+; CICA-4 e IR-42, a 40mg/litro de Al3+, e IAC-435, IAC-164, Pérola, Batatais, Pratão Precoce, Blue Bonnet, IAC-120, IAC-47, IAC-1246, IAC-25, IAC-165, Pratão, Dourado Precoce e CICA-8 foram tolerantes a 40mg/litro de Al3+. Quando foram utilizadas soluções nutritivas com temperatura de 30 ± 1°C, todos os cultivares de arroz estudados apresentaram melhor desenvolvimento radicular do que a 25 ± 1°C e se mostraram tolerantes a 5, 10 e 20mg/litro de Al3+. Com a concentração de 40mg/litro de Al3+, os cultivares Dourado Precoce, CICA-4, IR-42, IR-43, IR-45, IR-8, IAC-899, IR-665-4-5-5 e IR-841 foram sensíveis; IAC-47, Blue Bonnet, IAC-1246, IAC-164, Pratão, Pratão Precoce, CICA-8, IAC-435, IAC-120, IAC-25, IAC-165, Pérola e Batatais, tolerantes. A presença do alumínio nas soluções nutritivas foi prejudicial a todos os cultivares tolerantes e sensíveis. Os dados obtidos permitiram classificar os cultivares estudados nas seguintes classes de tolerância ao alumínio: tolerantes: IAC-435, IAC-120, IAC-47, IAC-1246, IAC-25, IAC-165, IAC-164, Pérola, Batatais, Pratão Precoce, Blue Bonnet; moderadamente tolerantes: Pratão, Dourado Precoce e CICA-8, e sensíveis: CICA-4, IR-42, IR-43, IR-45, IR-8, IAC-899, IR-665-4-5-5 e IR-841.Twenty two rice cultivars were studied in nutrient solution in

  18. Hybrid male sterility in rice is due to epistatic interactions with a pollen killer locus.

    Science.gov (United States)

    Kubo, Takahiko; Yoshimura, Atsushi; Kurata, Nori

    2011-11-01

    In intraspecific crosses between cultivated rice (Oryza sativa) subspecies indica and japonica, the hybrid male sterility gene S24 causes the selective abortion of male gametes carrying the japonica allele (S24-j) via an allelic interaction in the heterozygous hybrids. In this study, we first examined whether male sterility is due solely to the single locus S24. An analysis of near-isogenic lines (NIL-F(1)) showed different phenotypes for S24 in different genetic backgrounds. The S24 heterozygote with the japonica genetic background showed male semisterility, but no sterility was found in heterozygotes with the indica background. This result indicates that S24 is regulated epistatically. A QTL analysis of a BC(2)F(1) population revealed a novel sterility locus that interacts with S24 and is found on rice chromosome 2. The locus was named Epistatic Factor for S24 (EFS). Further genetic analyses revealed that S24 causes male sterility when in combination with the homozygous japonica EFS allele (efs-j). The results suggest that efs-j is a recessive sporophytic allele, while the indica allele (EFS-i) can dominantly counteract the pollen sterility caused by S24 heterozygosity. In summary, our results demonstrate that an additional epistatic locus is an essential element in the hybrid sterility caused by allelic interaction at a single locus in rice. This finding provides a significant contribution to our understanding of the complex molecular mechanisms underlying hybrid sterility and microsporogenesis.

  19. Metagenomic of Actinomycetes Based on 16S rRNA and nifH Genes in Soil and Roots of Four Indonesian Rice Cultivars Using PCR-DGGE

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    Mahyarudin

    2015-07-01

    Full Text Available The research was conducted to study the metagenomic of actinomycetes based on 16S ribosomal RNA (rRNA and bacterial nifH genes in soil and roots of four rice cultivars. The denaturing gradient gel electrophoresis profile based on 16S rRNA gene showed that the diversity of actinomycetes in roots was higher than soil samples. The profile also showed that the diversity of actinomycetes was similar in four varieties of rice plant and three types of agroecosystem. The profile was partially sequenced and compared to GenBank database indicating their identity with closely related microbes. The blast results showed that 17 bands were closely related ranging from 93% to 100% of maximum identity with five genera of actinomycetes, which is Geodermatophilus, Actinokineospora, Actinoplanes, Streptomyces and Kocuria. Our study found that Streptomyces species in soil and roots of rice plants were more varied than other genera, with a dominance of Streptomyces alboniger and Streptomyces acidiscabies in almost all the samples. Bacterial community analyses based on nifH gene denaturing gradient gel electrophoresis showed that diversity of bacteria in soils which have nifH gene was higher than that in rice plant roots. The profile also showed that the diversity of those bacteria was similar in four varieties of rice plant and three types of agroecosystem. Five bands were closely related with nifH gene from uncultured bacterium clone J50, uncultured bacterium clone clod-38, and uncultured bacterium clone BG2.37 with maximum identity 99%, 98%, and 92%, respectively. The diversity analysis based on 16S rRNA gene differed from nifH gene and may not correlate with each other. The findings indicated the diversity of actinomycetes and several bacterial genomes analyzed here have an ability to fix nitrogen in soil and roots of rice plant.

  20. Suppression or knockout of SaF/SaM overcomes the Sa-mediated hybrid male sterility in rice

    Institute of Scientific and Technical Information of China (English)

    Yongyao Xie; Baixiao Niu; Yunming Long; Gousi Li; Jintao Tang; Yaling Zhang; Ding Ren; Yao-Guang Liu; Letian Chen

    2017-01-01

    Hybrids between the indica and japonica subspecies of rice (Oryza sativa) are usually sterile, which hinders utilization of heterosis in the inter-subspecific hybrid breeding. The complex locus Sa comprises two adjacently located genes, SaF and SaM, which interact to cause abortion of pollen grains carrying the japonica allele in japonica-indica hybrids. Here we showed that silencing of SaF or SaM by RNA interference restored male fertility in indica-japonica hybrids with heterozygous Sa. We further used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-based genome editing to knockout the SaF and SaM alleles, respectively, of an indica rice line to create hybrid-compatible lines. The resultant artificial neutral alleles did not affect pollen viability and other agricultural traits, but did break down the reproductive barrier in the hybrids. We found that some rice lines have natural neutral allele Sa-n, which was compatible with the typical japonica or indica Sa alleles in hybrids. Our results demonstrate that SaF and SaM are required for hybrid male sterility, but are not essential for pollen development. This study provides effective approaches for the generation of hybrid-compatible lines by knocking out the Sa locus or using the natural Sa-n allele to overcome hybrid male sterility in rice breeding.

  1. Suppression or knockout of SaF/SaM overcomes the Sa-mediated hybrid male sterility in rice.

    Science.gov (United States)

    Xie, Yongyao; Niu, Baixiao; Long, Yunming; Li, Gousi; Tang, Jintao; Zhang, Yaling; Ren, Ding; Liu, Yao-Guang; Chen, Letian

    2017-09-01

    Hybrids between the indica and japonica subspecies of rice (Oryza sativa) are usually sterile, which hinders utilization of heterosis in the inter-subspecific hybrid breeding. The complex locus Sa comprises two adjacently located genes, SaF and SaM, which interact to cause abortion of pollen grains carrying the japonica allele in japonica-indica hybrids. Here we showed that silencing of SaF or SaM by RNA interference restored male fertility in indica-japonica hybrids with heterozygous Sa. We further used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-based genome editing to knockout the SaF and SaM alleles, respectively, of an indica rice line to create hybrid-compatible lines. The resultant artificial neutral alleles did not affect pollen viability and other agricultural traits, but did break down the reproductive barrier in the hybrids. We found that some rice lines have natural neutral allele Sa-n, which was compatible with the typical japonica or indica Sa alleles in hybrids. Our results demonstrate that SaF and SaM are required for hybrid male sterility, but are not essential for pollen development. This study provides effective approaches for the generation of hybrid-compatible lines by knocking out the Sa locus or using the natural Sa-n allele to overcome hybrid male sterility in rice breeding. © 2017 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc. © 2017 Institute of Botany, Chinese Academy of Sciences.

  2. Spatial and Spectral Hybrid Image Classification for Rice Lodging Assessment through UAV Imagery

    Directory of Open Access Journals (Sweden)

    Ming-Der Yang

    2017-06-01

    Full Text Available Rice lodging identification relies on manual in situ assessment and often leads to a compensation dispute in agricultural disaster assessment. Therefore, this study proposes a comprehensive and efficient classification technique for agricultural lands that entails using unmanned aerial vehicle (UAV imagery. In addition to spectral information, digital surface model (DSM and texture information of the images was obtained through image-based modeling and texture analysis. Moreover, single feature probability (SFP values were computed to evaluate the contribution of spectral and spatial hybrid image information to classification accuracy. The SFP results revealed that texture information was beneficial for the classification of rice and water, DSM information was valuable for lodging and tree classification, and the combination of texture and DSM information was helpful in distinguishing between artificial surface and bare land. Furthermore, a decision tree classification model incorporating SFP values yielded optimal results, with an accuracy of 96.17% and a Kappa value of 0.941, compared with that of a maximum likelihood classification model (90.76%. The rice lodging ratio in paddies at the study site was successfully identified, with three paddies being eligible for disaster relief. The study demonstrated that the proposed spatial and spectral hybrid image classification technology is a promising tool for rice lodging assessment.

  3. Responses of Yield Characteristics to High Temperature During Flowering Stage in Hybrid Rice Guodao 6

    Directory of Open Access Journals (Sweden)

    Guan-fu FU

    2008-09-01

    Full Text Available By sowing at different dates during 2005 and 2006 both in paddy fields and greenhouse, a super hybrid rice combination Guodao 6 and a conventional hybrid rice combination Xieyou 46 (as control were used to analyze the differences in heat injury index, seed setting rate, grain yield and its components. Guodao 6 showed more stable yield and spikelet fertility, and lower heat injury index than Xieyou 46. Further studies indicated that the spikelet sterility is positively correlated with the average daily temperature and the maximum daily temperature, with the coefficients of 0.8604 and 0.9850 (P<0.05 respectively in Guodao 6. The effect of high temperature injury on seed setting caused by maximum daily temperature was lower than that by average daily temperature during the grain filling stage.

  4. Biomass saccharification is largely enhanced by altering wall polymer features and reducing silicon accumulation in rice cultivars harvested from nitrogen fertilizer supply.

    Science.gov (United States)

    Zahoor; Sun, Dan; Li, Ying; Wang, Jing; Tu, Yuanyuan; Wang, Yanting; Hu, Zhen; Zhou, Shiguang; Wang, Lingqiang; Xie, Guosheng; Huang, Jianliang; Alam, Aftab; Peng, Liangcai

    2017-11-01

    In this study, two rice cultivars were collected from experimental fields with seven nitrogen fertilizer treatments. All biomass samples contained significantly increased cellulose contents and reduced silica levels, with variable amounts of hemicellulose and lignin from different nitrogen treatments. Under chemical (NaOH, CaO, H 2 SO 4 ) and physical (hot water) pretreatments, biomass samples exhibited much enhanced hexoses yields from enzymatic hydrolysis, with high bioethanol production from yeast fermentation. Notably, both degree of polymerization (DP) of cellulose and xylose/arabinose (Xyl/Ara) ratio of hemicellulose were reduced in biomass residues, whereas other wall polymer features (cellulose crystallinity and monolignol proportion) were variable. Integrative analysis indicated that cellulose DP, hemicellulosic Xyl/Ara and silica are the major factors that significantly affect cellulose crystallinity and biomass saccharification. Hence, this study has demonstrated that nitrogen fertilizer supply could largely enhance biomass saccharification in rice cultivars, mainly by reducing cellulose DP, hemicellulosic Xyl/Ara and silica in cell walls. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Two neutral alleles of improving male gamete abortion in indica-japonica hybrid rice

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@It was difficult to use the pronounced heterosis of indica-japonica hybrids rice due to the panicle sterility caused by male and female gamete abortion. The female gamete abortion in most of subspecific hybrids could be solved by using an abortion-neutral gene S5-n, a wide compatibility gene. The problem of male gamete abortion indicated by distorted segregation of marker genes remained to be studied. Segregation distortion via male gamete had been reported on chromosomes 3, 7, 8, 11, and 12.

  6. Responses of different water spinach cultivars and their hybrid to Cd, Pb and Cd-Pb exposures.

    Science.gov (United States)

    Xin, Junliang; Huang, Baifei; Yang, Zhongyi; Yuan, Jiangang; Dai, Hongwen; Qiu, Qiu

    2010-03-15

    A pot experiment was conducted to investigate the stability of Cd and/or Pb accumulation in shoot of Cd and Pb pollution-safe cultivars (PSCs), the hereditary pattern of shoot Cd accumulation, and the transfer potentials of Cd and Pb in water spinach (Ipomoea aquatica Forsk.). A typical Cd-PSC, a typical non-Cd-PSC (Cd accumulative cultivar), a hybrid from the former two cultivars, and two typical Cd+Pb-PSCs were grown in seven soils with different concentrations of Cd and Pb. The results showed that concentrations of Cd and Pb in shoot of the PSCs were always lower than the non-PSC and the highest Cd and Pb transfer factors were also always observed in the non-PSC, indicating the stability of the PSCs in Cd and Pb accumulation. Shoot Cd concentration seemed to be controlled by high Cd dominant gene(s) and thus crossbreeding might not minimize Cd accumulation in water spinach. Interaction between Cd and Pb in soils affected the accumulations of the metals in shoot of water spinach. Under middle Cd and Pb treatments, the presence of higher Pb promoted the accumulation of Cd. However, under high Pb treatment, accumulations of Cd and Pb were both restricted. (c) 2009 Elsevier B.V. All rights reserved.

  7. A novel two T-DNA binary vector allows efficient generation of marker-free transgenic plants in three elite cultivars of rice (Oryza sativa L.).

    Science.gov (United States)

    Breitler, Jean-Christophe; Meynard, Donaldo; Van Boxtel, Jos; Royer, Monique; Bonnot, François; Cambillau, Laurence; Guiderdoni, Emmanuel

    2004-06-01

    A pilot binary vector was constructed to assess the potential of the 2 T-DNA system for generating selectable marker-free progeny plants in three elite rice cultivars (ZhongZuo321, Ariete and Khao Dawk Mali 105) known to exhibit contrasting amenabilities to transformation. The first T-DNA of the vector, delimited by Agrobacterium tumefaciens borders, contains the hygromycin phosphotransferase (hpt) selectable gene and the green fluorescent protein (gfp) reporter gene while the second T-DNA, delimited by Agrobacterium rhizogenes borders, bears the phosphinothricin acetyl transferase (bar) gene, featuring the gene of interest. 82-90% of the hygromycin-resistant primary transformants exhibited tolerance to ammonium glufosinate mediated by the bar gene suggesting very high co-transformation frequency in the three cultivars. All of the regenerated plants were analyzed by Southern blot which confirmed co-integration of the T-DNAs at frequencies consistent with those of co-expression and allowed determination of copy number for each gene as well as detection of two different vector backbone fragments extending between the two T-DNAs. Hygromycin susceptible, ammonium glufosinate tolerant phenotypes represented 14.4, 17.4 and 14.3% of the plants in T1 progenies of ZZ321, Ariete and KDML105 primary transformants, respectively. We developed a statistical model for deducing from the observed copy number of each T-DNA in T0 plants and phenotypic segregations in T1 progenies the most likely constitution and linkage of the T-DNA integration locus. Statistical analysis identified in 40 out of 42 lines a most likely linkage configuration theoretically allowing genetic separation of the two T-DNA types and out segregation of the T-DNA bearing the bar gene. Overall, though improvements of the technology would be beneficial, the 2 T-DNA system appeared to be a useful approach to generate selectable marker-free rice plants with a consistent frequency among cultivars.

  8. Application of space mutation on creation of rice new material and breeding of new variety

    International Nuclear Information System (INIS)

    Pu Zhigang; Zhang Zhiyong; Xiang Yuewu; Cai Pingzhong; Zhou Xianming; Zhang Zhixiong

    2008-01-01

    One rice material with quasi-aromatic and special color-glumes has been selected through space mutation. A new cytoplasmic male sterile line was transferred from the special rice material. The abortive fertility of sterility is stable, its restoring and combining ability is well. The rice quality of Huaxiang A reaches the third grade rice high-quality standard. A new high yielding hybrid rice cultivar (Huaxiang 7) was bred from the cytoplasmic male sterile line 'Huaxiang A' and restorer line 'Chuanhui 907', which already passed provincinal evaluation. (authors)

  9. Distribution of assimilates derived from canopy leaves at different milky stage of intergeneric high-yielding hybrid rice

    International Nuclear Information System (INIS)

    Tang Jianjun

    1997-01-01

    Distribution characteristics of assimilates derived from 14 C-glucose fed on different canopy leaves of the high-yielding intergeneric hybrid rice Yuanyou 1 and GER-1, intra-varietal 3-line hybrid rice Shanyou 63, maternal and paternal parents of intergeneric hybrid rice at various ripening stage from flowering stage to late milky stage were studied with pot experiments under greenhouse in 1993 and 1994 in Guangzhou. The results indicates that there exists a significant difference in exportation of radioactivity from the leaf fed, partitioning of radioactivity exported into different organs and importation accumulation percent of total radioactivity in the rice panicle Yuanyou 1 has a high average exportation percent, importation accumulation percent and a stable and sustainable grain-filling process, which results in a high seed-setting rate with large spikelet population

  10. Response of the leaf photosynthetic rate to available nitrogen in erect panicle-type rice (Oryza sativa L. cultivar, Shennong265

    Directory of Open Access Journals (Sweden)

    Chihiro Urairi

    2016-07-01

    Full Text Available Increasing the yield of rice per unit area is important because of the demand from the growing human population in Asia. A group of varieties called erect panicle-type rice (EP achieves very high yields under conditions of high nitrogen availability. Little is known, however, regarding the leaf photosynthetic capacity of EP, which may be one of the physiological causes of high yield. We analyzed the factors contributing to leaf photosynthetic rate (Pn and leaf mesophyll anatomy of Nipponbare, Takanari, and Shennong265 (a EP type rice cultivar varieties subjected to different nitrogen treatments. In the field experiment, Pn of Shennong265 was 33.8 μmol m−2 s−1 in the high-N treatment, and was higher than that of the other two cultivars because of its high leaf nitrogen content (LNC and a large number of mesophyll cells between the small vascular bundles per unit length. In Takanari, the relatively high value of Pn (31.5 μmol m−2 s−1 was caused by the high stomatal conductance (gs; .72 mol m−2 s−1 in the high-N treatment. In the pot experiment, the ratio of Pn/Ci to LNC, which may reflect mesophyll conductance (gm, was 20–30% higher in Nipponbare than in Takanari or Shennong265 in the high N availability treatment. The photosynthetic performance of Shennong265 might be improved by introducing the greater ratio of Pn/Ci to LNC found in Nipponbare and greater stomatal conductance found in Takanari.

  11. Hybrid Sterility in Rice (Oryza sativa L.) Involves the Tetratricopeptide Repeat Domain Containing Protein.

    Science.gov (United States)

    Yu, Yang; Zhao, Zhigang; Shi, Yanrong; Tian, Hua; Liu, Linglong; Bian, Xiaofeng; Xu, Yang; Zheng, Xiaoming; Gan, Lu; Shen, Yumin; Wang, Chaolong; Yu, Xiaowen; Wang, Chunming; Zhang, Xin; Guo, Xiuping; Wang, Jiulin; Ikehashi, Hiroshi; Jiang, Ling; Wan, Jianmin

    2016-07-01

    Intersubspecific hybrid sterility is a common form of reproductive isolation in rice (Oryza sativa L.), which significantly hampers the utilization of heterosis between indica and japonica varieties. Here, we elucidated the mechanism of S7, which specially causes Aus-japonica/indica hybrid female sterility, through cytological and genetic analysis, map-based cloning, and transformation experiments. Abnormal positioning of polar nuclei and smaller embryo sac were observed in F1 compared with male and female parents. Female gametes carrying S7(cp) and S7(i) were aborted in S7(ai)/S7(cp) and S7(ai)/S7(i), respectively, whereas they were normal in both N22 and Dular possessing a neutral allele, S7(n) S7 was fine mapped to a 139-kb region in the centromere region on chromosome 7, where the recombination was remarkably suppressed due to aggregation of retrotransposons. Among 16 putative open reading frames (ORFs) localized in the mapping region, ORF3 encoding a tetratricopeptide repeat domain containing protein was highly expressed in the pistil. Transformation experiments demonstrated that ORF3 is the candidate gene: downregulated expression of ORF3 restored spikelet fertility and eliminated absolutely preferential transmission of S7(ai) in heterozygote S7(ai)/S7(cp); sterility occurred in the transformants Cpslo17-S7(ai) Our results may provide implications for overcoming hybrid embryo sac sterility in intersubspecific hybrid rice and utilization of hybrid heterosis for cultivated rice improvement. Copyright © 2016 by the Genetics Society of America.

  12. Resposta de cultivares de arroz a doses de nitrogênio e do regulador de crescimento cloreto de clormequat Response of rice cultivars to nitrogen and growth regulator chlormequat chloride

    Directory of Open Access Journals (Sweden)

    Salatiér Buzetti

    2006-12-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos de doses de nitrogênio (0, 50, 100 e 150 kg ha-1 e do regulador de crescimento cloreto de clormequat (0, 1 e 2 L ha-1, em algumas características agronômicas de cultivares de arroz IAC 201 e IAC 202. O delineamento experimental foi o de blocos ao acaso, com quatro repetições. O N foi aplicado em cobertura, no estádio da diferenciação floral, e o regulador de crescimento foi aplicado parceladamente, aos 20 e 30 dias após a emergência das plântulas de arroz (perfilhamento. Na safra 2001/2002, houve efeito significativo de N para altura de plantas, comprimento da panícula, espiguetas por panícula, massa de 100 grãos e produtividade de grãos. Houve efeito do regulador de crescimento sobre o comprimento da panícula e espiguetas por panícula. A maior produtividade foi a da cultivar IAC 202. Na safra 2002/2003, houve efeito de N para altura de plantas, massa de 100 grãos, fertilidade das espiguetas e produtividade de grãos. O regulador de crescimento não exerceu efeito nas características testadas, e a cultivar IAC 202 foi novamente a mais produtiva.The objective of this work was to evaluate N rates (0, 50, 100 and 150 kg ha-1 and the growth regulator chlormequat chloride effect (0, 1 e 2 L ha-1 on some agronomic characteristics of rice cultivars IAC 201 and IAC 202. The experimental design was a randomized block with four replicates. Nitrogen was applied as side-dressing at flower differentiation and the growth regulator was split in two times and applied at 20 and 30 days after seedlings emergency (tillering. In the harvests of 2001/2002, there was no significant effect of N rates on plant height, panicle length, spikelet per panicle, 100-grain mass and grain yield. The growth regulator rates were significant for panicle length and spikelet per panicle. IAC 202 presented higher grain yield. In the harvest of 2002/2003 there was no effect of N rates on plant height, spikelet

  13. Application Of Induced Mutation Combined With Hybridization Method In Rice Improvement In Southern Vietnam

    International Nuclear Information System (INIS)

    Do Khac Thinh; Dao Minh So; Nguyen Thi Cuc; Hung Phi Oanh; Hoang Duc Dung

    2008-01-01

    Rice plays an important role of social-economic issues in Vietnam, especially in Mekong River Delta (MRD). Rice mutation breeding was not initiated until 1992 in Southern Vietnam. Therefore, no mutant rice varieties were cultivated in MRD before 1995. Dry and germinated seeds of varieties as IR64, Tam Xoan, Nang Huong were exposed to 60 Co gamma rays at doses of 200-300 Gy. Population of 10,000-15,000 M1 plants were established by direct seeded practice. Mutant elite lines were used in hybridization program, assessed according to the standard system for rice (IRRI 1996) from M2 - M7 generations. The promising selected lines were tested in multi-location trials. The mutated characters developed so far consist of better resistance to lodging, disease and insect damages, higher tolerance to soil stresses such as acid sulphate, drought etc, and also earliness and higher yield potential. Mutation techniques have shown very useful in rice improvement, especially for characters controlled by close linked genes that are difficult to break by recombination. Some best mutant varieties: VND95-19, VND95-20, VND99-3, TNDB-100 have been released for large-scale production in MRD. Among them, VND95-20 has become one of the top 5 varieties for export and grown annually about 300,000 ha in Southern Vietnam. In combination with hybridization method, some mutants gave promising recombinants in aroma, tolerance to BPH, Grassy Stunt Virus and Ragged Stunt Virus diseases. Selected varieties as VN121, VN24-4 are largely released into production in recent time. (author)

  14. Evaluation of low light intensity at three phenological stages in the agronomic and physiological responses of two rice (Oryza sativa L. cultivars

    Directory of Open Access Journals (Sweden)

    Hermann Restrepo

    2013-08-01

    Full Text Available A study was carried out to assess the effect of two irradiance levels (100 and 50% natural light at three different growth stages on yield and physiological characteristics of two rice cultivars (Fedearroz 50 and Fedearroz 733. The plants were exposed to low irradiance for 5 days consecutive by using black net cloth (about 50% of normal at the panicle primordium, flowering and grain filling stages. The obtained results showed that the leaf chlorophyll content (SPAD readings was higher in rice leaves under low irradiance. The chlorophyll content from the shade treatment apparently remained constant until the grain filling phase, then decreased slightly in the 'F50' rice plants and remarkably in the 'F733' plants. Stomatal conductance (gs was negatively affected by shading, with the effect being more adverse in the 'F733' plants. At the flowering and grain filling phases, grain yield was reduced by the low light treatments by around ~20% in the 'F50' plants. While, in 'F733', they were only affected by shading at the grain filling stage, causing a decrease of around 25%. These results seem to indicate that "F773" may have a better capacity for partitioning dry matter than "F50" in spite of the fact that the gas exchange characteristics were conditioned by low irradiance conditions at the reproductive and ripening phases

  15. Evidence for the Emergence of New Rice Types of Interspecific Hybrid Origin in West African Farmers' Fields

    NARCIS (Netherlands)

    Nuijten, H.A.C.P.; Treuren, van R.; Struik, P.C.; Mokuwa, G.A.; Okry, F.; Teeken, B.W.E.; Richards, P.

    2009-01-01

    In West Africa two rice species (Oryza glaberrima Steud. and Oryza sativa L.) co-exist. Although originally it was thought that interspecific hybridization is impossible without biotechnological methods, progenies of hybridization appear to occur in farmer fields. AFLP analysis was used to assess

  16. Novel QTLs affecting rice kernel fissure resistance discovered in the cultivar ‘Saber’ augment those from ‘Cybonnet’

    Science.gov (United States)

    Kernel fissures in rice (Oryza sativa L.) caused by pre- or post-harvest stresses are the leading cause of breakage among milled rice. Such breakage causes economic losses for producers, millers, and marketers. Five QTLs for kernel fissure resistance (FR) were identified among a set of 275 RILs de...

  17. Mapping and validation of QTLs for cold tolerance at seedling stage in rice from an indica cultivar Habiganj Boro VI (Hbj.BVI).

    Science.gov (United States)

    Biswas, Partha S; Khatun, Hasina; Das, Nomita; Sarker, Md Mahathir; Anisuzzaman, M

    2017-12-01

    Yellowing, stunting, and seedling death associated with cold stress is a common problem in many Asian countries for winter rice cultivation. Improvement of cultivars through marker-assisted selection of QTLs for cold tolerance at seedling stage from locally adapted germplasm/cultivar is the most effective and sustainable strategy to resolve this problem. A study was undertaken to map QTLs from 151 F 2:3 progenies of a cross between a cold susceptible variety, BR1 and a locally adapted traditional indica cultivar, Hbj.BVI. A total of six significant QTLs were identified for two cold tolerance indices-cold-induced leaf discoloration and survival rate after a recovery period of seven days on chromosomes 6, 8, 11, and 12. Among these QTLs, qCTSL - 8 - 1 and qCTSS - 8 - 1 being co-localized into RM7027-RM339 on chromosome 8 and qCTSL - 12 - 1 and qCTSS - 12 - 1 into RM247-RM2529 on chromosome 12 showed 12.78 and 14.96% contribution, respectively, to the total phenotypic variation for cold tolerance. Validation of QTL effect in BC 1 F 3 population derived a cross between a cold susceptible BRRI dhan28 and Hbj.BVI showed dominating effect of qCTSL - 12 - 1 on cold tolerance at seedling stage and it became stronger when one or more other QTLs were co-segregated with it. These results suggest that the QTLs identified in this study are stable and effective on other genetic background also, which warrant the use of these QTLs for further study aiming to cultivar development for seedling stage cold tolerance.

  18. Genomic structural variation-mediated allelic suppression causes hybrid male sterility in rice.

    Science.gov (United States)

    Shen, Rongxin; Wang, Lan; Liu, Xupeng; Wu, Jiang; Jin, Weiwei; Zhao, Xiucai; Xie, Xianrong; Zhu, Qinlong; Tang, Huiwu; Li, Qing; Chen, Letian; Liu, Yao-Guang

    2017-11-03

    Hybrids between divergent populations commonly show hybrid sterility; this reproductive barrier hinders hybrid breeding of the japonica and indica rice (Oryza sativa L.) subspecies. Here we show that structural changes and copy number variation at the Sc locus confer japonica-indica hybrid male sterility. The japonica allele, Sc-j, contains a pollen-essential gene encoding a DUF1618-domain protein; the indica allele, Sc-i, contains two or three tandem-duplicated ~ 28-kb segments, each carrying an Sc-j-homolog with a distinct promoter. In Sc-j/Sc-i hybrids, the high-expression of Sc-i in sporophytic cells causes suppression of Sc-j expression in pollen and selective abortion of Sc-j-pollen, leading to transmission ratio distortion. Knocking out one or two of the three Sc-i copies by CRISPR/Cas9 rescues Sc-j expression and male fertility. Our results reveal the gene dosage-dependent allelic suppression as a mechanism of hybrid incompatibility, and provide an effective approach to overcome the reproductive barrier for hybrid breeding.

  19. High/low nitrogen adapted hybrid of rice cultivars and their ...

    African Journals Online (AJOL)

    Other four types were lying in the middle with moderate adaptability of nitrogen. Furthermore, five varieties were selected from each of the mentioned six types and then grew in N-free conditions to investigate their performance on lack of N. The results showed that type 1, the dry weight of the materials originally growing in ...

  20. High/low nitrogen adapted hybrid of rice cultivars and their ...

    African Journals Online (AJOL)

    User

    2011-05-09

    May 9, 2011 ... Other four types were lying in the middle with moderate adaptability of ... nitrogen, to reduce environmental pollution and the waste. *Corresponding ...... controls nutrient-induced changes in root architecture.Science.279:.

  1. Detection of Alien Oryza punctata Kotschy Chromosomes in Rice, Oryza sativa L., by Genomic in situ Hybridization

    OpenAIRE

    Yasui, Hideshi; Nonomura, Ken-ichi; Iwata, Nobuo; 安井, 秀; 野々村, 賢一; 岩田, 伸夫

    1997-01-01

    Genomic in situ hybridization (GIS H) using total Oryza punctata Kotschy genomic DNA as a probe was applied to detect alien chromosomes transferred from O. punctata (W1514: 2n=2x=24: BB) to O. sativa Japonica cultivar, Nipponbare (2n=2x=24: AA). Only 12 chromosomes in the interspecific hybrids (2n=3x=36: AAB) between autotetraploid of O. sativa cultivar Nipponbare and a diploid strain of O. punctata (W1514) showed intense staining by FITC in mitotic metaphase spreads. Only one homologous pair...

  2. Physiological effects of endogenous IAA on grain filling of hybrid rice Xieyou 9308

    International Nuclear Information System (INIS)

    Tao Longxing; Wang Xi; Zhang Fudao

    2003-01-01

    The progress of grain filling and effects of TIBA and PCIB on sugar content and IAA level in superior and inferior spikelets of hybrid rice Xieyou 9308 and its restorer R-9308 were studied. The grain weight increment rate and sugar (fructose, glucose and sucrose) in superior spikelets were higher than those in inferior spikelets until 7 days after pollination, then, they were higher in inferior spikelets than those in superior ones. The differences of physiological activities between superior and inferior spikelets were more significant in combinations than in their restorers. IAA inhibitors decreased 3 H-IAA and 3 H-Try contents in both superior and inferior spikelets, reduced the efficiency of 3 H-Try bio-transforming to 3 H-IAA in rice plant and, therefor, reduced 3 H-glucose in grain. By treatment with high concentration of exogenous IAA on young panicle before heading, the grain-setting difference between superior and inferior spikelets was significantly decreased, and the total grain setting rate increased, indicating that IAA impels the grain filling progress in hybrid rice

  3. Uptake, translocation and transformation of antimony in rice (Oryza sativa L.) seedlings.

    Science.gov (United States)

    Cai, Fei; Ren, Jinghua; Tao, Shu; Wang, Xilong

    2016-02-01

    Antimony (Sb), as a toxic metalloid, has been gaining increasing research concerns due mainly to its severe pollution in many places. Rice has been identified to be the dominant intake route of Sb by residents close to the Sb mining areas. A hydroponic experiment was conducted to investigate the difference in uptake, translocation and transformation of Sb in rice seedlings of four cultivars exposed to 0.2 or 1.0 mg/L of Sb(V). The results showed that mass concentration of iron plaque (mg/kg FW) formed at the root surfaces of cultivar N was the highest among all tested cultivars at both low and high exposure levels of Sb(V). The accumulated Sb concentration in iron plaque significantly increased with an increase in mass concentration of iron plaque formed at the rice root. The total amount of iron plaque (mg/pot) at rice root generally increased with increasing exposed Sb(V) concentration, which was closely associated with the increasing lipid peroxidation in roots. Concentration percentage of Sb in rice root significantly reduced as the corresponding value in the iron plaque increased, suggesting that iron plaque formation strongly suppressed uptake of Sb by rice root. Sb concentration in rice tissues followed an order: root > stem, leaf. The japonica rice (cultivars N and Z) exhibited a stronger translocation tendency of Sb from root to stem than indica hybrid rice (cultivars F and G). Translocation of Sb from root of cultivar F to its stem and leaf was sharply enhanced with increasing Sb exposure concentration. Sb(V) could be reduced to Sb(III) in rice tissues, especially in stems (10-26% of the total Sb). For the sake of food safety, the difference in uptake, translocation and transformation of Sb in rice species planted in Sb-contaminated soils should be taken into consideration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Allelic interaction of F1 pollen sterility loci and abnormal chromosome behaviour caused pollen sterility in intersubspecific autotetraploid rice hybrids.

    Science.gov (United States)

    He, J H; Shahid, M Q; Li, Y J; Guo, H B; Cheng, X A; Liu, X D; Lu, Y G

    2011-08-01

    The intersubspecific hybrids of autotetraploid rice has many features that increase rice yield, but lower seed set is a major hindrance in its utilization. Pollen sterility is one of the most important factors which cause intersubspecific hybrid sterility. The hybrids with greater variation in seed set were used to study how the F(1) pollen sterile loci (S-a, S-b, and S-c) interact with each other and how abnormal chromosome behaviour and allelic interaction of F(1) sterility loci affect pollen fertility and seed set of intersubspecific autotetraploid rice hybrids. The results showed that interaction between pollen sterility loci have significant effects on the pollen fertility of autotetraploid hybrids, and pollen fertility further decreased with an increase in the allelic interaction of F(1) pollen sterility loci. Abnormal ultra-structure and microtubule distribution patterns during pollen mother cell (PMC) meiosis were found in the hybrids with low pollen fertility in interphase and leptotene, suggesting that the effect-time of pollen sterility loci interaction was very early. There were highly significant differences in the number of quadrivalents and bivalents, and in chromosome configuration among all the hybrids, and quadrivalents decreased with an increase in the seed set of autotetraploid hybrids. Many different kinds of chromosomal abnormalities, such as chromosome straggling, chromosome lagging, asynchrony of chromosome disjunction, and tri-fission were found during the various developmental stages of PMC meiosis. All these abnormalities were significantly higher in sterile hybrids than in fertile hybrids, suggesting that pollen sterility gene interactions tend to increase the chromosomal abnormalities which cause the partial abortion of male gametes and leads to the decline in the seed set of the autotetraploid rice hybrids. © 2011 The Author(s).

  5. Virulence Types of Magnaporthe oryzae to Hybrid Rice in Sichuan, China

    Directory of Open Access Journals (Sweden)

    Yu-lian BAI

    2012-12-01

    Full Text Available A total of 638 isolates of rice blast (Magnaporthe oryzae were isolated in 2002–2009 from different rice varieties in different regions of Sichuan, China and inoculated onto seven rice varieties (Lijiangxintuanheigu, IR24, Minghui 63, Duohui 1, Chenghui 448, Neihui 99-14 and RHR-1 to differentiate the virulence types of the fungus and trace the changes. The virulence to the seven varieties was respectively scored at 1, 2, 4, 8, 16, 32 and 64. The total scores of individual M. grisea isolates which were the sum of scores infecting differential varieties could, in turn, be used for the nomenclature of the virulence types due to their accordance to the special virulence patterns. The 638 tested isolates were then differentiated into 56 different virulence types. Type 15 virulent to Lijiangxintuanheigu, IR24 and Minghui 63, and Type 127 virulent to all of the seven varieties were the most dominant virulence types respectively with the occurrence frequencies of 15.99% and 15.83%. Type 19 and other seven virulence types were not monitored during 2002–2009. Type 15 was the predominant virulence type in 2002, 2003, 2004 and 2007, whereas Type 127 had been the most dominant virulence type after 2005 except for the year 2007 when the province underwent severe drought. Five hundred and seven out of the 638 tested isolates were virulent to Minghui 63, and 89.58% of the 384 isolates virulent to either Duohui 1, Chenghui 448 or Neihui 99-14 were virulent to Minghui 63, which indicated the impact of the extensive plantation of hybrid rice Minghui 63 as the restorer line on the virulence evolution of M. oryzae in Sichuan. The virulence pattern of the dominant virulence types suggested that the acquiring of virulence to all the major resistant restorer lines was the main routes of the evolution in virulence of M. oryzae to hybrid rice in Sichuan. The virulence frequencies of the 638 tested isolates to IR24, Minghui 63, Duohui 1, Chenghui 448, Neihui 99

  6. Uptake, translocation and transformation of antimony in rice (Oryza sativa L.) seedlings

    International Nuclear Information System (INIS)

    Cai, Fei; Ren, Jinghua; Tao, Shu; Wang, Xilong

    2016-01-01

    Antimony (Sb), as a toxic metalloid, has been gaining increasing research concerns due mainly to its severe pollution in many places. Rice has been identified to be the dominant intake route of Sb by residents close to the Sb mining areas. A hydroponic experiment was conducted to investigate the difference in uptake, translocation and transformation of Sb in rice seedlings of four cultivars exposed to 0.2 or 1.0 mg/L of Sb(V). The results showed that mass concentration of iron plaque (mg/kg FW) formed at the root surfaces of cultivar N was the highest among all tested cultivars at both low and high exposure levels of Sb(V). The accumulated Sb concentration in iron plaque significantly increased with an increase in mass concentration of iron plaque formed at the rice root. The total amount of iron plaque (mg/pot) at rice root generally increased with increasing exposed Sb(V) concentration, which was closely associated with the increasing lipid peroxidation in roots. Concentration percentage of Sb in rice root significantly reduced as the corresponding value in the iron plaque increased, suggesting that iron plaque formation strongly suppressed uptake of Sb by rice root. Sb concentration in rice tissues followed an order: root > stem, leaf. The japonica rice (cultivars N and Z) exhibited a stronger translocation tendency of Sb from root to stem than indica hybrid rice (cultivars F and G). Translocation of Sb from root of cultivar F to its stem and leaf was sharply enhanced with increasing Sb exposure concentration. Sb(V) could be reduced to Sb(III) in rice tissues, especially in stems (10–26% of the total Sb). For the sake of food safety, the difference in uptake, translocation and transformation of Sb in rice species planted in Sb-contaminated soils should be taken into consideration. - Highlights: • Sb(V) caused lipid peroxidation and increased iron plaque formation at root surface. • The iron plaque may suppress uptake of Sb by rice. • Cultivars

  7. Genetic transformation via Agrobacterium tumefaciens in embryogenic cell suspensions of the plantain hybrid cultivar FHIA 21 (AAAB

    Directory of Open Access Journals (Sweden)

    Boris Chong

    2002-01-01

    Full Text Available The genetic improvement of plantain and banana is of great importance for its level of consumption on a world-wide scale. Genetic transformation constitutes one alternative for genetic improvement and has complemented traditional techniques. In this work some parameters of genetic transformation of plantain were studied by means of transient expression of â-glucoronidase in the hybrid cultivar FHIA-21(AAAB by Agrobacterium tumefaciens. A study with the β-Agrobacterium tumefaciens strains AT-2260 and EHA-105, both with the plasmid pCAMBIA-3301 was done. A comparison between the time of infection and time of co-culture was studied. The strain of better behavior was EHA-105. In the study of the time of infection and co-culture, the best combination resulted to be the one with two hours of infection and six days of co-culture. Key words: At-2260, EHA-105, β-glucoronidase, Musa

  8. Screening and Expression of a Silicon Transporter Gene (Lsi1) in Wild-Type Indica Rice Cultivars

    Science.gov (United States)

    Abiri, Rambod; Kalhori, Nahid; Atabaki, Narges

    2017-01-01

    Silicon (Si) is one of the most prevalent elements in the soil. It is beneficial for plant growth and development, and it contributes to plant defense against different stresses. The Lsi1 gene encodes a Si transporter that was identified in a mutant Japonica rice variety. This gene was not identified in fourteen Malaysian rice varieties during screening. Then, a mutant version of Lsi1 was substituted for the native version in the three most common Malaysian rice varieties, MR219, MR220, and MR276, to evaluate the function of the transgene. Real-time PCR was used to explore the differential expression of Lsi1 in the three transgenic rice varieties. Silicon concentrations in the roots and leaves of transgenic plants were significantly higher than in wild-type plants. Transgenic varieties showed significant increases in the activities of the enzymes SOD, POD, APX, and CAT; photosynthesis; and chlorophyll content; however, the highest chlorophyll A and B levels were observed in transgenic MR276. Transgenic varieties have shown a stronger root and leaf structure, as well as hairier roots, compared to the wild-type plants. This suggests that Lsi1 plays a key role in rice, increasing the absorption and accumulation of Si, then alters antioxidant activities, and improves morphological properties. PMID:28191468

  9. Screening and Expression of a Silicon Transporter Gene (Lsi1 in Wild-Type Indica Rice Cultivars

    Directory of Open Access Journals (Sweden)

    Mahbod Sahebi

    2017-01-01

    Full Text Available Silicon (Si is one of the most prevalent elements in the soil. It is beneficial for plant growth and development, and it contributes to plant defense against different stresses. The Lsi1 gene encodes a Si transporter that was identified in a mutant Japonica rice variety. This gene was not identified in fourteen Malaysian rice varieties during screening. Then, a mutant version of Lsi1 was substituted for the native version in the three most common Malaysian rice varieties, MR219, MR220, and MR276, to evaluate the function of the transgene. Real-time PCR was used to explore the differential expression of Lsi1 in the three transgenic rice varieties. Silicon concentrations in the roots and leaves of transgenic plants were significantly higher than in wild-type plants. Transgenic varieties showed significant increases in the activities of the enzymes SOD, POD, APX, and CAT; photosynthesis; and chlorophyll content; however, the highest chlorophyll A and B levels were observed in transgenic MR276. Transgenic varieties have shown a stronger root and leaf structure, as well as hairier roots, compared to the wild-type plants. This suggests that Lsi1 plays a key role in rice, increasing the absorption and accumulation of Si, then alters antioxidant activities, and improves morphological properties.

  10. Screening and Expression of a Silicon Transporter Gene (Lsi1) in Wild-Type Indica Rice Cultivars.

    Science.gov (United States)

    Sahebi, Mahbod; Hanafi, Mohamed M; Rafii, M Y; Azizi, Parisa; Abiri, Rambod; Kalhori, Nahid; Atabaki, Narges

    2017-01-01

    Silicon (Si) is one of the most prevalent elements in the soil. It is beneficial for plant growth and development, and it contributes to plant defense against different stresses. The Lsi1 gene encodes a Si transporter that was identified in a mutant Japonica rice variety. This gene was not identified in fourteen Malaysian rice varieties during screening. Then, a mutant version of Lsi1 was substituted for the native version in the three most common Malaysian rice varieties, MR219, MR220, and MR276, to evaluate the function of the transgene. Real-time PCR was used to explore the differential expression of Lsi1 in the three transgenic rice varieties. Silicon concentrations in the roots and leaves of transgenic plants were significantly higher than in wild-type plants. Transgenic varieties showed significant increases in the activities of the enzymes SOD, POD, APX, and CAT; photosynthesis; and chlorophyll content; however, the highest chlorophyll A and B levels were observed in transgenic MR276. Transgenic varieties have shown a stronger root and leaf structure, as well as hairier roots, compared to the wild-type plants. This suggests that Lsi1 plays a key role in rice, increasing the absorption and accumulation of Si, then alters antioxidant activities, and improves morphological properties.

  11. Desempenho de populações híbridas F2 de arroz-vermelho (Oryza sativa com arroz transgênico (O. sativa resistente ao herbicida amonio-glufosinate Performance of F2 hybrid populations of red rice (Oryza sativa with ammonium-glufosinate-resistant transgenic rice (O. sativa

    Directory of Open Access Journals (Sweden)

    J.A. Noldin

    2004-09-01

    -preto. Mesmo assim, os usuários dessa tecnologia deverão adotar, obrigatoriamente, medidas que evitem a possibilidade de cruzamento entre o arroz transgênico e o arroz-vermelho ou arroz-preto.Red rice is an important weed in paddy rice fields. The use of ammonium glufosinate - resistant genetically modified (GM rice cultivars is a viable alternative for controlling red rice in cultivated rice crops. The objective of this study was to evaluate the behavior of F2 hybrid population derivates of crossing between ammonium glufosinate - resistant GM rice and red rice. The F2 hybrid population derivates of crossing between GM rice and red rice are viable but do not present any apparent competitive advantage over red rice. The morphological characteristics of the F2 hybrid populations, such as tillering capacity, number of leaves produced and average plant height were partly reduced and partly unaffected by the introgression of the bar gene. The period between rice planting and 50% flowering increased in the red rice x GM rice F2 hybrids, compared to the parental red rice and GM rice. Average seed shattering rate in the four hybrid families was lower than in the red rice ecotypes, with such aspect also being unfavorable to the persistence of red rice in the environment. Seed dormancy of the hybrids was similar to that of the red rice ecotypes. However, management practices should be adopted to avoid crossing between transgenic rice and red rice.

  12. Ethylene production and constitutive expression of ethylene receptors and ethylene signal transduction during grain filling in apical and basal spikelets of compact-and lax-panicle rice (Oryza sativa cultivars

    Directory of Open Access Journals (Sweden)

    Sudhanshu Sekhar

    2017-12-01

    Full Text Available Grain yields in modern super rice cultivars do not always meet the expectations because many spikelets are located on secondary branches in closely packed homogeneous distribution in these plants, and they do not fill properly. The factors limiting grain filling of such spikelets, especially in the lower panicle branches, are elusive. Two long-duration rice cultivars differing in panicle density, Mahalaxmi (compact and Upahar (lax were cultivated in an open field plot. Grain filling, ethylene production and constitutive expression of ethylene receptors and ethylene signal transducers in apical and basal spikelets of the panicle were compared during the early post-anthesis stage, which is the most critical period for grain development. In another experiment, a similar assessment was made for the medium-duration cultivars compact-panicle OR-1918 and lax-panicle Lalat. Grain weight of the apical spikelets was always higher than that of the basal spikelets. This gradient of grain weight was wide in the compact-panicle cultivars and narrow in the lax-panicle cultivars. Compared to apical spikelets, the basal spikelets produced more ethylene at anthesis and retained the capacity for post-anthesis expression of ethylene receptors and ethylene signal transducers longer. High ethylene production enhanced the expression of the RSR1 gene, but reduced expression of the GBSS1 gene. Ethylene inhibited the partitioning of assimilates of developing grains resulting in low starch biosynthesis and high accumulation of soluble carbohydrates. It is concluded that an increase in grain/spikelet density in rice panicles reduces apical dominance to the detriment of grain filling by production of ethylene and/or enhanced perception of the ethylene signal. Ethylene could be a second messenger for apical dominance in grain filling. The manipulation of the ethylene signal would possibly improve rice grain yield.

  13. The effectiveness of preplant seed bio-invigoration techniques using Bacillus sp. CKD061 to improving seed viability and vigor of several local upland rice cultivars of Southeast Sulawesi

    Science.gov (United States)

    Sutariati, G. A. K.; Bande, L. O. S.; Khaeruni, A.; Muhidin; Mudi, L.; Savitri, R. M.

    2018-02-01

    Research was aimed to evaluate the bio-invigoration techniques using Bacillus sp. CKD061 in improving seed viability and vigor of local upland rice. The research is arranged in factorial with completely randomized design (CRD). The different upland rice cultivars as first factor that consists of 11 cultivars, namely: Pae Tinangge, Pae Rowu, Pae Uwa, Pae Tanta, Pae Waburi-Buri, Pae Mornene, Pae Indalibana, Pae Lawarangka, Pae Huko, Pae Wagamba and Pae Momea. The second factor is the seed bio-invigoration technique, consists of 5 treatments, namely: without seed bio-invigoration (B0), NaCl + Bacillus sp. CKD061 (B1), KNO3 + Bacillus sp. CKD061 (B2), Ground burned-rice husk + Bacillus sp. CKD061 (B3), and Ground brick + Bacillus sp. CKD061 (B4). The results showed that seed bio-invigoration using Bacillus sp. CKD061 gave effect on the seed viability and vigor. Interaction of the seed bio-invigoration and upland rice cultivars were able to improve seed viability and vigor. Seed bio-invigoration ttreatment using ground brick + Bacillus sp. CKD061 was the best treatment, which could improve the viability and vigor of Pae Waburi-Buri, Pae Mornene and Pae Indalibana. The treatment increased vigor index by 133% in Pae Waburi-Buri and 127% in Pae Mornene, and Pae Indalibana compared with control.

  14. Immediate Genetic and Epigenetic Changes in F1 Hybrids Parented by Species with Divergent Genomes in the Rice Genus (Oryza.

    Directory of Open Access Journals (Sweden)

    Ying Wu

    Full Text Available Inter-specific hybridization occurs frequently in higher plants, and represents a driving force of evolution and speciation. Inter-specific hybridization often induces genetic and epigenetic instabilities in the resultant homoploid hybrids or allopolyploids, a phenomenon known as genome shock. Although genetic and epigenetic consequences of hybridizations between rice subspecies (e.g., japonica and indica and closely related species sharing the same AA genome have been extensively investigated, those of inter-specific hybridizations between more remote species with different genomes in the rice genus, Oryza, remain largely unknown.We investigated the immediate chromosomal and molecular genetic/epigenetic instability of three triploid F1 hybrids produced by inter-specific crossing between species with divergent genomes of Oryza by genomic in situ hybridization (GISH and molecular marker analysis. Transcriptional and transpositional activity of several transposable elements (TEs and methylation stability of their flanking regions were also assessed. We made the following principle findings: (i all three triploid hybrids are stable in both chromosome number and gross structure; (ii stochastic changes in both DNA sequence and methylation occurred in individual plants of all three triploid hybrids, but in general methylation changes occurred at lower frequencies than genetic changes; (iii alteration in DNA methylation occurred to a greater extent in genomic loci flanking potentially active TEs than in randomly sampled loci; (iv transcriptional activation of several TEs commonly occurred in all three hybrids but transpositional events were detected in a genetic context-dependent manner.Artificially constructed inter-specific hybrids of remotely related species with divergent genomes in genus Oryza are chromosomally stable but show immediate and highly stochastic genetic and epigenetic instabilities at the molecular level. These novel hybrids might

  15. Effects of silicon on seed setting rate of rice intersubspecific hybrids.

    Science.gov (United States)

    Li, W-C; Zhang, L; Wang, J; Wang, D; Wang, T-X; Duan, C-X

    2015-09-01

    The present study found semi-sterility in rice intersubspecific hybrids of 'Taichung 65' x 'Guangluai 4' and 'Ludao' x 'Qiuguang'. Embryo sac fertility was evaluated using the overall staining transparent method. The results showed that the embryo sac contained a normal egg cell, normal synergid cells, polar nuclei cells, and antipodal cells, indicating that semi-sterility was caused mainly by pollen semi-sterility. In the pot experiment, the effects of silicon on the seed-setting rate of the two intersubspecific hybrids were examined. The results showed that the rate of anther dehiscence, number of pollen per stigma of Fl plants, potential of pollen grain germination, and fertility of the spikelet were significantly improved by the utilization of silicon fertilizer.

  16. Impact of mutation breeding in rice

    International Nuclear Information System (INIS)

    Rutger, J.N.

    1992-01-01

    More cultivars have been developed in rice through the use of mutation breeding than in any other crop. Direct releases of mutants as cultivars began some 30 years ago, and now total 198 cultivars. During the last 20 years, increasing use has been made of induced mutants in cross-breeding programs, leading to 80 additional cultivars. Principal improvements through mutation breeding have been earlier maturity, short stature, and grain character modifications. Rice has been a popular subject of mutagenesis because it is the world's leading food crop, has diploid inheritance, and is highly self-pollinated. In recent years induced mutation has been exploited to develop breeding tool mutants, which are defined as mutants that in themselves may not have direct agronomic application but may be useful genetic tools for crop improvement. Examples include the eui gene, hull colour mutants, normal genetic male steriles, and environmentally sensitive genetic male steriles. The environmentally sensitive genetic male steriles, especially those in which male sterility can be turned on or off by different photoperiod lengths, show promise for simplifying hybrid rice seed production both in China and the USA. Future applications of mutation in rice include induction of unusual endosperm starch types, plant types with fewer but more productive tillers, dominant dwarfs, dominant genetic male steriles, extremely early maturing mutants, nutritional mutants, and in vitro-derived mutants for tolerance to herbicides or other growth stresses. Refs, 4 figs, 2 tabs

  17. Comportamento de cultivares de arroz irrigado em relação a fungos manchadores de sementes Performance of lowland rice cultivam to seed discoloration fungi

    Directory of Open Access Journals (Sweden)

    Jaciro Soave

    1985-01-01

    , pois foram superiores ou iguais ao controle em todos os parâmetros analisados.Aiming to detect rice seed discoloration fungi, the behavior of 37 lowland rice cultivars to each of them was determined in two field trials carried out with three replications in two sites of the State of São Paulo (Tremembé and Pindamonhangaba, Brazil, in 1980/81. Seed samples were drawn from the whole yield of each experimental plot. Spotted and spotless seeds were visually separated and discolored seed (DS% and weight loss percentages (WL% calculated. From each treatment 50 spotted and 50 spotless seeds were plated separately in Petri dishes and incubated by the blotter method. The following fungi species were detected: Alternaria sp., Cephalosporium sp., Cladosportum spp., Corynespora sp., Curvularia spp., Epicoccum spp., Fusarium moniliforme, Helminthosporium oryzae, Phoma spp., Pyricularia oryzae, Rhizoctonia solani, Rhynchosporium oryzae, Trichoconiella padwickii, Trichoderma sp. e Trichothecium sp. In relation to the number of seeds infected with each fungus, highly significant statistical differences between spotted and spotless seeds were detected for H. oryzae, Phoma spp., R. oryae and T. padwickii. They were considered as causal agents of the spots. The statistical analysis of ihe data related to each parameter showed that a variable number of cultivars out performed the commercial control, as to each respective parameter studied: 32 as to DS%; 4 as to WL%; 24 as to H. oryzae; 6 as to Phoma spp.; all cultivars as to R. oryzae and 11 as to P. padwickii. The statistical analysis of all parameters in the two sites showed the cultivars PI-1291, PI-1356, PI-1377, IR-1544, P2-S1-78, L-17-72, P2-48, P2-S2 and GI-6904-6 as the best ones when compared with the commercial control IAC-899.

  18. Marker-Assisted Selection of Xa21 Conferring Resistance to Bacterial Leaf Blight in indica Rice Cultivar LT2

    Directory of Open Access Journals (Sweden)

    Hue Thi Nguyen

    2018-01-01

    Full Text Available Bacterial leaf blight of rice (BLB, caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient parent. IRBB21, which carries the Xa21 gene, was used as the donor parent. The resistance gene Xa21 was introduced into LT2 by marker-assisted backcrossing. Three Xoo races were used to inoculate the improved lines following the clipping method. Eleven BC3F3 lines carrying Xa21 were obtained based on molecular markers and agronomic performance. The 11 lines were then inoculated with the three Xoo races. All the 11 improved lines showed better resistance to BLB than the recipient parent LT2. Based on the level of resistance to BLB and their agronomic performance, five lines (BC3F3 5.1.5.1, BC3F3 5.1.5.12, BC3F3 8.5.6.44, BC3F3 9.5.4.1 and BC3F3 9.5.4.23 were selected as the most promising for commercial release. These improved lines could contribute to rice production in terms of food security.

  19. Marker-Assisted Selection of Xa21 Conferring Resistance to Bacterial Leaf Blight in indica Rice Cultivar LT2

    Institute of Scientific and Technical Information of China (English)

    Hue Thi NGUYEN; Trung Nguyen DINH; Nakano TOSHITSUGU; Liet Van VU; Quang Hong VU; Tan Van MAI; Thu Thi NGUYEN; Lam Duc VU; Tung Thanh NGUYEN; Long Viet NGUYEN; Hien Thu Thi VU; Hue Thi NONG

    2018-01-01

    Bacterial leaf blight of rice (BLB), caused by Xanthomonas oryzae pv. oryzae, is one of the most destructive diseases in Asian rice fields. A high-quality rice variety, LT2, was used as the recipient parent. IRBB21, which carries the Xa21 gene, was used as the donor parent. The resistance gene Xa21 was introduced into LT2 by marker-assisted backcrossing. Three Xoo races were used to inoculate the improved lines following the clipping method. Eleven BC3F3lines carrying Xa21 were obtained based on molecular markers and agronomic performance. The 11 lines were then inoculated with the three Xoo races. All the 11 improved lines showed better resistance to BLB than the recipient parent LT2. Based on the level of resistance to BLB and their agronomic performance, five lines (BC3F35.1.5.1, BC3F35.1.5.12, BC3F38.5.6.44, BC3F3 9.5.4.1 and BC3F39.5.4.23) were selected as the most promising for commercial release. These improved lines could contribute to rice production in terms of food security.

  20. Cultivar specific plant-soil feedback overrules soil legacy effects of elevated ozone in a rice-wheat rotation system

    NARCIS (Netherlands)

    Li, Qi; Yang, Yue; Bao, Xuelian; Zhu, Jianguo; Liang, Wenju; Bezemer, T. Martijn

    2016-01-01

    Abstract Tropospheric ozone has been recognized as one of the most important air pollutants. Many studies have shown that elevated ozone negatively impacts yields of important crops such as wheat or rice, but how ozone influences soil ecosystems of these crops and plant growth in rotation systems is

  1. Dissipation of phenanthrene and pyrene at the aerobic-anaerobic soil interface: differentiation induced by the rhizosphere of PAH-tolerant and PAH-sensitive rice (Oryza sativa L.) cultivars.

    Science.gov (United States)

    He, Yan; Xia, Wen; Li, Xinfeng; Lin, Jiajiang; Wu, Jianjun; Xu, Jianming

    2015-03-01

    A pot experiment was conducted to reveal the removal of two polycyclic aromatic hydrocarbons (PAHs) (phenanthrene, PHE, and pyrene, PYR) during rice cultivation in a paddy field. The rhizosphere effect on facilitating dissipation of PAHs varied simultaneously as a function of soil properties, PAH types, cultivation time, and genotypes within rice cultivars, with differences performed for PYR but not PHE. Changes in soil PLFA profiles evidenced that the growth of rice roots modified the dominant species within rhizosphere microbial communities and induced a selective enrichment of Gram-negative aerobic bacteria capable of degrading, thereby resulting in the differentiated dissipation of PYR. While the insignificant differences in PHE dissipation might be attributed to its higher solubility and availability under flooded condition that concealed the differences in improvement of bioavailability for microorganisms between rhizosphere and non-rhizosphere, and between both soils and both rice cultivars. Our findings illustrate that the removal of PAHs in paddy soils was more complex relative to those in dryland soils. This was possibly due to the specialty of rice roots for oxygen secretion that provides development of redox heterogeneous microbial habitats at root-soil interface under flooded condition.

  2. Construction of a male sterility system for hybrid rice breeding and seed production using a nuclear male sterility gene

    OpenAIRE

    Chang, Zhenyi; Chen, Zhufeng; Wang, Na; Xie, Gang; Lu, Jiawei; Yan, Wei; Zhou, Junli; Tang, Xiaoyan; Deng, Xing Wang

    2016-01-01

    Nuclear male sterility is common in flowering plants, but its application in hybrid breeding and seed production is limited because of the inability to propagate a pure male sterile line for commercial hybrid seed production. Here, we characterized a rice nuclear gene essential for sporophytic male fertility and constructed a male sterility system that can propagate the pure male sterile seeds on a large scale. This system is fundamentally advantageous over the current cytoplasmic male steril...

  3. Molecular Breeding of Rice Restorer Lines and Hybrids for Brown Planthopper (BPH) Resistance Using the Bph14 and Bph15 Genes.

    Science.gov (United States)

    Wang, Hongbo; Ye, Shengtuo; Mou, Tongmin

    2016-12-01

    The development of hybrid rice is a practical approach for increasing rice production. However, the brown planthopper (BPH), Nilaparvata lugens Stål, causes severe yield loss of rice (Oryza sativa L.) and can threaten food security. Therefore, breeding hybrid rice resistant to BPH is the most effective and economical strategy to maintain high and stable production. Fortunately, numerous BPH resistance genes have been identified, and abundant linkage markers are available for molecular marker-assisted selection (MAS) in breeding programs. Hence, we pyramided two BPH resistance genes, Bph14 and Bph15, into a susceptive CMS restorer line Huahui938 and its derived hybrids using MAS to improve the BPH resistance of hybrid rice. Three near-isogenic lines (NILs) with pyramided Bph14 and Bph15 were obtained by molecular marker-assisted backcross (MAB) and phenotypic selection. The genomic components of these NILs were detected using the whole-genome SNP (Single nucleotide polymorphism) array, RICE6K, suggesting that the recurrent parent genome (RPG) recovery of the NILs was 87.88, 87.70 and 86.62 %, respectively. BPH bioassays showed that the improved NILs and their derived hybrids carrying homozygous Bph14 and Bph15 were resistant to BPH. However, the hybrids with heterozygous Bph14 and Bph15 remained susceptible to BPH. The developed NILs showed no significant differences in major agronomic traits and rice qualities compared with the recurrent parent. Moreover, the improved hybrids derived from the NILs exhibited better agronomic performance and rice quality compared with the controls under natural field conditions. This study demonstrates that it is essential to stack Bph14 and Bph15 into both the maternal and paternal parents for developing BPH-resistant hybrid rice varieties. The SNP array with abundant DNA markers is an efficient tool for analyzing the RPG recovery of progenies and can be used to monitor the donor segments in NILs, thus being extremely important

  4. Doses de boro e crescimento radicular e da parte aérea de cultivares de arroz de terras altas Influence of boron addition on growth of roots and shoot of upland rice crops

    Directory of Open Access Journals (Sweden)

    Juliano Corulli Corrêa

    2006-12-01

    Full Text Available O crescimento radicular é favorecido em condições adequadas de disponibilidade de boro no solo e, por isto, a aplicação da dose correta desse micronutriente é de grande importância, para que não ocorra prejuízo no desenvolvimento e na produtividade da cultura de arroz de terras altas, de acordo com a variedade e tipo de solo. O presente trabalho teve como objetivo avaliar a influência das doses de boro no crescimento radicular e da parte aérea, em três cultivares de arroz de terras altas. O experimento foi realizado em casa de vegetação, em vaso com capacidade de 10 L, que continha 8 dm³ de solo Latossolo Vermelho distrófico, sendo o delineamento experimental inteiramente casualizado, em esquema fatorial 3 x 3, com quatro repetições. Os tratamentos consistiram de três cultivares (Caiapó, Primavera e Maravilha e três doses de boro (0, 3 e 6 mg dm-3, usando, como fonte, o bórax. A dose de 6 mg dm-3 foi prejudicial tanto à produção de matéria seca da parte aérea como de raiz para o arroz de terras altas. Além de apresentar maior capacidade de absorção de boro, o cultivar Maravilha apresentou-se mais tolerante à elevação da disponibilidade de B no solo, não ocorrendo alterações de comprimento, diâmetro e superfície radicular.Appropriate boron (B availability in soils favors root growth, and a sufficient supply of this micronutrient is very important for adequate rice development and yield in upland fields, depending on the cultivars and soil type. This study aimed at evaluating the influence of B addition on growth of roots and shoot of three upland rice cultivars. The experiment was carried out in a greenhouse, in 10 L pots containing 8 kg of an Hapludox; the experiment was in a completely random 3 x 3 factorial design, with four replications. The treatments consisted of three rice cultivars (Caiapó, Primavera, and Maravilha and three B rates (0, 3 and 6 mg dm-3, as borax. The B rate of 6 mg dm-3 boron was

  5. Genome constitution and evolution in Lolium X Festuca hybrid cultivars (Festulolium)

    Czech Academy of Sciences Publication Activity Database

    Kopecký, David; Loureiro, J.; Zwierzykowski, Z.; Ghesquière, M.; Doležel, Jaroslav

    2006-01-01

    Roč. 113, - (2006), s. 731-742 ISSN 0040-5752 R&D Projects: GA AV ČR IBS5038104 Institutional research plan: CEZ:AV0Z50380511 Keywords : Festulolium hybrids * GISH * FISH Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.715, year: 2006

  6. DISTANT HYBRIDS IN F4 (VITIS VINIFERA L. X MUSCADINIA ROTUNDIFOLIA MICHX. AND OF CULTIVARS OF VITIS VINIFERA L. AND OF CONCERNING THE CONTENT OF SOME BIOCHEMICAL COMPOUNDS

    Directory of Open Access Journals (Sweden)

    Eugeniu ALEXANDROV

    2015-04-01

    Full Text Available The process of obtaining distant hybrids, as well as any crossing of cultivars of Vitis vinifera L. with representatives of species possessing the necessary qualities (resistance to diseases and pests, low temperature, etc. may change the spectrum of chemical and biochemical compounds responsible for flavour, colour and taste of grapes, obtained juice and wine. Botanical description of distant hybrids was performed during all phases of the vegetative stages; the organs of the plants were studied from spring, at bud unfolding, until early autumn, at the fall of the leaves. For the determination of diglucoside-3,5-malvidin, the fluorimetric method, for determining the methyl anthranilate, the gas chromatographic method was applied. Based on the analyzes of biochemical constituents of grapes of the distant hybrids: DRX-M4-578; -502; -571; -660; -609; -580; etc., compared to the traditional cultivars „Feteasca albă” and „Rară neagră”, it has been found that these varieties are similar. So, the distant hybrids of grapevine haven’t inherited unwanted characters for vines, some of them are strictly limited (diglucoside-3,5-malvidol. These hybrids don’t have the specific characteristics of direct production hybrids, characterised by the foxat taste of the grape berries, caused by the presence of the methyl anthranilate. The distant hybrids studied according to the classical uvologic and technological principles can be classified as follows: 5 distant hybrids are attributed to the table vine species and 2 distant hybrids have mixed properties. According to the physical and biochemical indices of the grapes of the studied distant hybrids, their characteristics are similar to European vine species.

  7. Genetic analysis and hybrid vigor study of grain yield and other quantitative traits in auto tetraploid rice

    International Nuclear Information System (INIS)

    Shahid, M.Q.; Xiong, C.Z.; Juan, L.Y.; Ming, X.H.

    2011-01-01

    Genetic analysis and genotype-by-environment interaction for important traits of auto tetraploid rice were evaluated by additive, dominance and additive X additive model. It was show n that genetic effects had more influence on grain yield and other quantitative traits of auto tetraploid rice than genotypic environment interaction. Plant height, panicle length, seed set , grain yield, dry matter production and 1000-grain weight we re mainly regulated by dominance variance. Additive and additive X additive gene action constructed the main proportion of genetic variance for heading date (flowering), number of panicles, grains per panicle, grain length, however grain width was supposed to be affected by additive X additive and dominance variance. Flag leaf length and width, fresh weight, peduncle length, unfilled grains and awn length were greatly influenced by genotypic environment interaction. Heading date produced highly negative heterosis over mid parent (H pm) and better parent ( H pb), whereas H pm and H pb were detected to be highly positive and significant for grain yield, seed set, peduncle length, filled grains and 1000-grain weight in F/sub 1/ and F/sub 2/ generations. The results indicated that auto tetraploid hybrids 96025 X Jackson (indica/japonica), 96025 X Linglun (indica/indica) and Linglun X Jackson (indica/japonica) showed highly significant hybrid vigor with improved seed set percentage and grain yield. These results suggest that intra-specific auto tetraploid rice hybrids have more hybrid vigor as compared to intra-sub specific auto tetraploid rice hybrids and auto tetraploid rice has the potential to be used for further studies and commercial application. (author)

  8. Effects of water management practices on residue decomposition and degradation of Cry1Ac protein from crop-wild Bt rice hybrids and parental lines during winter fallow season.

    Science.gov (United States)

    Xiao, Manqiu; Dong, Shanshan; Li, Zhaolei; Tang, Xu; Chen, Yi; Yang, Shengmao; Wu, Chunyan; Ouyang, Dongxin; Fang, Changming; Song, Zhiping

    2015-12-01

    Rice is the staple diet of over half of the world's population and Bacillus thuringiensis (Bt) rice expressing insecticidal Cry proteins is ready for deployment. An assessment of the potential impact of Bt rice on the soil ecosystem under varied field management practices is urgently required. We used litter bags to assess the residue (leaves, stems and roots) decomposition dynamics of two transgenic rice lines (Kefeng6 and Kefeng8) containing stacked genes from Bt and sck (a modified CpTI gene encoding a cowpea trypsin inhibitor) (Bt/CpTI), a non-transgenic rice near-isoline (Minghui86), wild rice (Oryza rufipogon) and crop-wild Bt rice hybrid under contrasting conditions (drainage or continuous flooding) in the field. No significant difference was detected in the remaining mass, total C and total N among cultivars under aerobic conditions, whereas significant differences in the remaining mass and total C were detected between Kefeng6 and Kefeng8 and Minghui86 under the flooded condition. A higher decomposition rate constant (km) was measured under the flooded condition compared with the aerobic condition for leaf residues, whereas the reverse was observed for root residues. The enzyme-linked immunosorbent assay (ELISA), which was used to monitor the changes in the Cry1Ac protein in Bt rice residues, indicated that (1) the degradation of the Cry1Ac protein under both conditions best fit first-order kinetics, and the predicted DT50 (50% degradation time) of the Cry1Ac protein ranged from 3.6 to 32.5 days; (2) the Cry1Ac protein in the residue degraded relatively faster under aerobic conditions; and (3) by the end of the study (~154 days), the protein was present at a low concentration in the remaining residues under both conditions. The degradation rate constant was negatively correlated with the initial carbon content and positively correlated with the initial Cry1Ac protein concentration, but it was only correlated with the mass decomposition rate constants under

  9. Pyramiding and evaluation of three dominant brown planthopper resistance genes in the elite indica rice 9311 and its hybrids.

    Science.gov (United States)

    Hu, Jie; Cheng, Mingxing; Gao, Guanjun; Zhang, Qinglu; Xiao, Jinghua; He, Yuqing

    2013-07-01

    Brown planthopper (BPH), Nilaparvata lugens Stål, is the most devastating insect pest in rice-producing areas. Three dominant BPH resistance genes (Bph14, Bph15, Bph18) were pyramided into elite indica rice 9311 and its hybrids using marker-assisted selection. Gene effectiveness was evaluated on the basis of seedling and adult rice resistance, honeydew weight and survival rate of BPH. All three genes affected BPH growth and development and antibiotic factors, resulting in both seedling and adult resistance. Bph15 had the greatest effect on conferring resistance to BPH. The results showed an additive effect of pyramiding genes, the order of the gene effect being 14/15/18 ≥ 14/15 > 15/18 ≥ 15 > 14/18 ≥ 14 ≥ 18 > none. The pyramided or single-gene introgression hybrids showed greater resistance than conventional hybrids, although the heterozygous genotypes had weaker effects than the corresponding homozygous genotypes. Furthermore, field trial data demonstrated that yields of improved 9311 lines were higher than or similar to that of the control under natural field conditions. These improved versions can be immediately used in hybrid improvement and production. Compared with controls, pyramided lines and hybrids with three genes showed the strongest resistance to BPH, without a yield decrease. © 2012 Society of Chemical Industry.

  10. Soma térmica de algumas fases do ciclo de desenvolvimento da escala de COUNCE para cultivares Sul-Brasileiras de arroz irrigado Thermal time of some developmental phases of the COUNCE scale for irrigated rice cultivars grown in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Nereu Augusto Streck

    2007-01-01

    Full Text Available A escala de COUNCE é uma escala de desenvolvimento de arroz recente que vem sendo gradativamente adotada no Brasil. No entanto, a duração das fases em ºC dia dessa escala ainda não está disponível para as cultivares brasileiras de arroz irrigado. Sendo assim, o objetivo deste trabalho foi determinar a soma térmica de algumas fases do ciclo de desenvolvimento da escala de COUNCE para cultivares Sul-Brasileiras de arroz irrigado, utilizando-se diversos métodos de cálculo e diferentes temperaturas cardinais ao longo do ciclo de desenvolvimento. Um experimento a campo foi desenvolvido em Santa Maria, RS, durante dois anos agrícolas (2003/2004 e 2004/2005 e com cinco épocas de semeadura em cada um deles. O delineamento experimental foi o inteiramente casualizado com quatro repetições. Cada repetição consistia de um vaso de 12 litros com 10 plantas. As datas dos estágios de desenvolvimento R2 (aparecimento do colar da folha bandeira e R9 (todos os grãos com casca marrom da escala de COUNCE foram registradas no colmo principal de cinco plantas por vaso. As cultivares utilizadas foram IRGA 421, IRGA 416, IRGA 417, IRGA 420, BR-IRGA 409, BRS 7 TAIM e EPAGRI 109. Considerando-se as temperaturas cardinais de 11 °C, 28 °C e 40 °C, a soma térmica para completar a fase emergência-R2 foi de 700-800 °C dia na cultivar muito precoce, 1000-1400 °C dia nas cultivares precoces e 1300-1700 °C dia nas cultivares médias e tardia, e a soma térmica para completar a fase R2-R9 foi de 400-700 °C dia e sem relação com o ciclo da cultivar.The COUNCE scale is a developmental scale recently proposed for rice and that is being used in Brazil. However, the duration of developmental phases of this scale in degree-days is not available for Brazilian irrigated rice cultivars. Thus, the objective of this study was to determine the thermal time of some developmental phases of the COUNCE scale in irrigated rice cultivars grown in Southern Brazil using

  11. Transcriptome and Cell Physiological Analyses in Different Rice Cultivars Provide New Insights Into Adaptive and Salinity Stress Responses

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    Elide Formentin

    2018-03-01

    Full Text Available Salinity tolerance has been extensively investigated in recent years due to its agricultural importance. Several features, such as the regulation of ionic transporters and metabolic adjustments, have been identified as salt tolerance hallmarks. Nevertheless, due to the complexity of the trait, the results achieved to date have met with limited success in improving the salt tolerance of rice plants when tested in the field, thus suggesting that a better understanding of the tolerance mechanisms is still required. In this work, differences between two varieties of rice with contrasting salt sensitivities were revealed by the imaging of photosynthetic parameters, ion content analysis and a transcriptomic approach. The transcriptomic analysis conducted on tolerant plants supported the setting up of an adaptive program consisting of sodium distribution preferentially limited to the roots and older leaves, and in the activation of regulatory mechanisms of photosynthesis in the new leaves. As a result, plants resumed grow even under prolonged saline stress. In contrast, in the sensitive variety, RNA-seq analysis revealed a misleading response, ending in senescence and cell death. The physiological response at the cellular level was investigated by measuring the intracellular profile of H2O2 in the roots, using a fluorescent probe. In the roots of tolerant plants, a quick response was observed with an increase in H2O2 production within 5 min after salt treatment. The expression analysis of some of the genes involved in perception, signal transduction and salt stress response confirmed their early induction in the roots of tolerant plants compared to sensitive ones. By inhibiting the synthesis of apoplastic H2O2, a reduction in the expression of these genes was detected. Our results indicate that quick H2O2 signaling in the roots is part of a coordinated response that leads to adaptation instead of senescence in salt-treated rice plants.

  12. Absorção e redução de nitrato em duas cultivares de arroz na presença de alumínio Uptake and reduction of nitrate in two rice cultivars in the presence of aluminum

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    Gilberto Costa Justino

    2006-08-01

    Full Text Available O objetivo deste trabalho foi estudar os efeitos do alumínio (Al sobre a absorção e a redução de nitrato, em duas cultivares de arroz: Fernandes (tolerante e Maravilha (sensível, expostas a 0 e 500 µM de Al. Depois de 21 dias de crescimento, foram determinados o comprimento, a produção de matéria seca, os teores de Al e de nitrato e a atividade in vitro da redutase do nitrato (RN, nas raízes e na parte aérea, bem como as constantes cinéticas de absorção de nitrato pelas raízes. O Al reduziu o crescimento em comprimento e a produção de matéria seca, nas duas partes das plantas, apenas da cultivar Maravilha. Os teores de Al aumentaram nas raízes e parte aérea das plantas nas duas cultivares, enquanto o teor de nitrato sofreu redução apenas nas raízes da cultivar Maravilha. A Vmax não se modificou, enquanto o Km da absorção de nitrato diminuiu cerca de 11% na cultivar Fernandes e aumentou 310% na Maravilha. Em presença de Al, houve redução na atividade da RN nas raízes das duas cultivares, e na parte aérea apenas da cultivar Maravilha. A cultivar tolerante foi mais eficiente na absorção e na redução de nitrato, o que indica que esses processos são importantes componentes da tolerância ao Al em arroz.The objective of this work was to evaluate the effects of Al on the nitrate uptake and reduction in two rice cultivars, Fernandes (Al tolerant and Maravilha (Al sensitive, exposed to 0 and 500 µM Al. After 21 days of Al treatment, growth in size and dry matter yield, Al and nitrate contents and in vitro nitrate reductase activity (NR in the tops and roots, and the kinetic constants of root nitrate uptake were determined. Aluminum reduced the growth and dry matter yield of both plant parts only in the Maravilha cultivar. Aluminum content increased in the tops and roots of both cultivars, while nitrate content decreased only in the roots of Maravilha cultivar. Vmax did not change, while Km of the nitrate uptake

  13. Effects of elevated ozone, carbon dioxide, and the combination of both on the grain quality of Chinese hybrid rice

    International Nuclear Information System (INIS)

    Wang, Yunxia; Song, Qiling; Frei, Michael; Shao, Zaisheng; Yang, Lianxin

    2014-01-01

    The effects of CO 2 and/or O 3 elevation on rice grain quality were investigated in chamber experiments with gas fumigation performed from transplanting until maturity in 2011 and 2012. Compared with the control (current CO 2 and O 3 concentration), elevated CO 2 caused a tendency of an increase in grain chalkiness and a decrease in mineral nutrient concentrations. In contrast, elevated O 3 significantly increased grain chalkiness and the concentrations of essential nutrients, while changes in starch pasting properties indicated a trend of deterioration in the cooking and eating quality. In the combination of elevated CO 2 and O 3 treatment, only chalkiness degree was significantly affected. It is concluded that the O 3 concentration projected for the coming few decades will have more substantial effects on grain quality of Chinese hybrid rice than the projected high CO 2 concentration alone, and the combination of two gases caused fewer significant changes in grain quality than individual gas treatments. - Highlights: • We investigated the effects of carbon dioxide and/or ozone elevation on rice grain quality. • Elevated ozone concentration had substantial effects on grain quality under current carbon dioxide concentration. • Elevated carbon dioxide concentration mitigated the impact of elevated ozone concentration on rice grain quality. - Exposure of Chinese hybrid rice to elevated ozone and CO 2 during growth causes fewer changes in grain quality than ozone exposure alone

  14. Fabrication and Performance Test of Aluminium Alloy-Rice Husk Ash Hybrid Metal Matrix Composite as Industrial and Construction Material

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    Md. Rahat Hossain

    2017-12-01

    Full Text Available Aluminium matrix composites (AMCs used extensively in various engineering fields due to their exceptional mechanical properties. In this present study, aluminium matrix composites (AMCs such as aluminium alloy (A356 reinforced with rice husk ash particles (RHA are made to explore the possibilities of reinforcing aluminium alloy. The stir casting method was applied to produce aluminium alloy (A356 reinforced with various amounts of (2%, 4%, and 6% rice husk ash (RHA particles. Physical treatment was carried out before the rice husk ash manufacturing process. The effect of mechanical strength of the fabricated hybrid composite was investigated. Therefore, impact test, tensile stress, compressive stress, and some other tests were carried out to analyse the mechanical properties. From the experimental results, it was found that maximum tensile, and compressive stress were found at 6% rice husk ash (RHA and aluminium matrix composites (AMCs. In future, the optimum percentages of rice husk ash (RHA to fabricate the hybrid composites will be determined. Also, simulation by finite element method (FEM will be applied for further investigation.

  15. Hybrid ternary rice paper-manganese oxide-carbon nanotube nanocomposites for flexible supercapacitors

    Science.gov (United States)

    Jiang, Wenchao; Zhang, Kaixi; Wei, Li; Yu, Dingshan; Wei, Jun; Chen, Yuan

    2013-10-01

    Modern portable electronic devices create a strong demand for flexible energy storage devices. Paper based nanocomposites are attractive as sustainable materials for such applications. Here, we directly explored the hydroxyl chemistry of cellulose fibers to synthesize hybrid ternary nanocomposites, comprised of rice paper, single-walled carbon nanotubes (SWCNTs) and manganese oxide nanoparticles. The functional groups on cellulose fibers can react with adsorbed permanganate ions, resulting in uniform deposition of manganese oxide nanoparticles. SWCNTs coated on top of manganese oxide nanoparticles form a highly conductive network connecting individual manganese oxide particles. By using the hybrid ternary composites as electrodes, the assembled two-electrode supercapacitors demonstrated high capacitance (260.2 F g-1), energy (9.0 W h kg-1), power (59.7 kW kg-1), and cycle stability (12% drop after 3000 cycles). In addition, the nanocomposites show good strength and excellent mechanical flexibility, and their capacitance shows negligible changes after bending more than 100 times. These findings suggest that opportunities exist to further explore the rich chemistry of cellulose fibers for innovative energy applications.Modern portable electronic devices create a strong demand for flexible energy storage devices. Paper based nanocomposites are attractive as sustainable materials for such applications. Here, we directly explored the hydroxyl chemistry of cellulose fibers to synthesize hybrid ternary nanocomposites, comprised of rice paper, single-walled carbon nanotubes (SWCNTs) and manganese oxide nanoparticles. The functional groups on cellulose fibers can react with adsorbed permanganate ions, resulting in uniform deposition of manganese oxide nanoparticles. SWCNTs coated on top of manganese oxide nanoparticles form a highly conductive network connecting individual manganese oxide particles. By using the hybrid ternary composites as electrodes, the assembled two

  16. Tungsten (W) bioavailability in paddy rice soils and its accumulation in rice (Oryza sativa).

    Science.gov (United States)

    James, Blessing; Zhang, Weili; Sun, Pei; Wu, Mingyan; Li, Hong Hong; Khaliq, Muhammad Athar; Jayasuriya, Pathmamali; James, Swithin; Wang, Guo

    2017-12-01

    The aim of this study was to investigate the accumulation characteristics of tungsten (W) by different indica rice cultivars from the soil and to assess the potential risks to human health via dietary intake of W in rice consumption. A total of 153 rice (ear) samples of 15 cultivars and the corresponding surface soil samples were collected from 7 cities in Fujian Province of southeastern China. The available soil W were extracted using H 2 C 2 O 4 ·2H 2 O-(NH 4 ) 2 C 2 O 4 ·H 2 O at pH 3.3). Results showed that the total soil W ranged from 2.03 mg kg -1 to 15.34 mg kg -1  and available soil W ranged from 0.03 mg kg -1 to 1.61 mg kg -1 . The W concentration in brown rice varied from 7 μg kg -1 to 283 μg kg -1 and was significantly correlated with the available soil W. The highest mean TF avail (transfer factor based on available soil W) was 0.91 for Te-you 627 (hybrid, indica rice), whereas the lowest was 0.08 for Yi-you 673 (hybrid, indica rice). The TF avail decreased with the increase in available soil W, clay content, and cation exchange capacity. The consumption of the brown rice produced from the investigated areas in some cultivars by the present study may cause risks to human health.

  17. Effects of nitrogen fertilization strategies on nitrogen use efficiency in physiology, recovery, and agronomy and redistribution of dry matter accumulation and nitrogen accumulation in two typical rice cultivars in Zhejiang, China.

    Science.gov (United States)

    Xie, Wen-xia; Wang, Guang-huo; Zhang, Qi-chun; Guo, Hai-chao

    2007-03-01

    Field experiments were conducted in farmers' rice fields in 2001 and 2002 to study the effects of nitrogen (N) management strategies on N use efficiency in recovery (RE), agronomy (AE) and physiology (PE) and redistribution of dry matter accumulation (DMA) and nitrogen accumulation (NA) in two typical rice cultivars in Jinhua, Zhejiang Province. This study aimed mainly at identifying the possible causes of poor fertilizer N use efficiency (NUE) of rice in Zhejiang by comparing farmers' fertilizer practice (FFP) with advanced site-specific nutrient management (SSNM) and real-time N management (RTNM). The results showed that compared to FFP, SSNM and RTNM reduced DMA and NA before panicle initiation and increased DMA and NA at post-flowering. There is no significant difference between SSNM and FFP in post-flowering dry matter redistribution (post-DMR) and post-flowering nitrogen redistribution (post-NR). These results suggest that high input rate of fertilizer N and improper fertilizer N timing are the main factors causing low NUE of irrigated rice in the farmer's routine practice of Zhejiang. With SSNM, about 15% of the current total N input in direct-seeding early rice and 45% in single rice could be reduced without yield loss in Zhejiang, China.

  18. Characterization by Suppression Subtractive Hybridization of Transcripts That Are Differentially Expressed in Leaves of Anthracnose-Resistant Ramie Cultivar.

    Science.gov (United States)

    Xuxia, Wang; Jie, Chen; Bo, Wang; Lijun, Liu; Hui, Jiang; Diluo, Tang; Dingxiang, Peng

    2012-01-01

    For the purpose of screening putative anthracnose resistance-related genes of ramie ( Boehmeria nivea L. Gaud), a cDNA library was constructed by suppression subtractive hybridization using anthracnose-resistant cultivar Huazhu no. 4. The cDNAs from Huazhu no. 4, which were infected with Colletotrichum gloeosporioides , were used as the tester and cDNAs from uninfected Huazhu no. 4 as the driver. Sequencing analysis and homology searching showed that these clones represented 132 single genes, which were assigned to functional categories, including 14 putative cellular functions, according to categories established for Arabidopsis . These 132 genes included 35 disease resistance and stress tolerance-related genes including putative heat-shock protein 90, metallothionein, PR-1.2 protein, catalase gene, WRKY family genes, and proteinase inhibitor-like protein. Partial disease-related genes were further analyzed by reverse transcription PCR and RNA gel blot. These expressed sequence tags are the first anthracnose resistance-related expressed sequence tags reported in ramie.

  19. Evidence for the emergence of new rice types of interspecific hybrid origin in West African farmers' fields.

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    Edwin Nuijten

    2009-10-01

    Full Text Available In West Africa two rice species (Oryza glaberrima Steud. and Oryza sativa L. co-exist. Although originally it was thought that interspecific hybridization is impossible without biotechnological methods, progenies of hybridization appear to occur in farmer fields. AFLP analysis was used to assess genetic diversity in West Africa (including the countries The Gambia, Senegal, Guinea Bissau, Guinea Conakry, Sierra Leone, Ghana and Togo using 315 rice samples morphologically classified prior to analysis. We show evidence for farmer interspecific hybrids of African and Asian rice, resulting in a group of novel genotypes, and identify possible mechanisms for in-field hybridization. Spontaneous back-crossing events play a crucial role, resulting in different groups of genetic diversity in different regions developed by natural and cultural selection, often under adverse conditions. These new groups of genotypes may have potential relevance for exploitation by plant breeders. Future advances in crop development could be achieved through co-operation between scientists and marginalized farmer groups in order to address challenges of rapid adaptation in a world of increasing socio-political and climatic uncertainty.

  20. Comparison of the role of gibberellins and ethylene in response to submergence of two lowland rice cultivars, Senia and Bomba.

    Science.gov (United States)

    Dubois, Vincent; Moritz, Thomas; García-Martínez, José L

    2011-02-15

    We examined the gibberellin (GA) and ethylene regulation of submergence-induced elongation in seedlings of the submergence-tolerant lowland rice (Oryza sativa L.) cvs Senia and Bomba. Elongation was enhanced after germination to facilitate water escape and reach air. We found that submergence-induced elongation depends on GA because it was counteracted by paclobutrazol (an inhibitor of GA biosynthesis), an effect that was negated by GA(3). Moreover, in the cv Senia, submergence increased the content of active GA(1) and its immediate precursors (GA(53), GA(19) and GA(20)) by enhancing expression of several GA biosynthesis genes (OsGA20ox1 and -2, and OsGA3ox2), but not by decreasing expression of several OsGA2ox (GA inactivating genes). Senia seedlings, in contrast to Bomba seedlings, did not elongate in response to ethylene or 1-aminocyclopropane-1-carboxylic-acid (ACC; an ethylene precursor) application, and submergence-induced elongation was not reduced in the presence of 1-methylcyclopropene (1-MCP; an ethylene perception inhibitor). Ethylene emanation was similar in Senia seedlings grown in air and in submerged-grown seedlings following de-submergence, while it increased in Bomba. The expression of ethylene biosynthesis genes (OsACS1, -2 and -3, and OsACO1) was not affected in Senia, but expression of OsACS5 was rapidly enhanced in Bomba upon submergence. Our results support the conclusion that submergence elongation enhancement of lowland rice is due to alteration of GA metabolism leading to an increase in active GA (GA(1)) content. Interestingly, in the cv Senia, in contrast to cv Bomba, this was triggered through an ethylene-independent mechanism. Copyright © 2010 Elsevier GmbH. All rights reserved.

  1. [Inheritance of bc1 gene in intersubspecific hybrids of rice (Oryza sativa L.)].

    Science.gov (United States)

    Lü, Chuan-Gen; Zong, Shou-Yu; Zhao, Ling; Qi, Qing-Ming; Zou, Jiang-Shi; Ikehashi, Hiroshi

    2004-10-01

    Distorted segregation of the brittle culm-1 gene (bc1) on rice chromosome 3 was found with greatly increased or decreased frequency of bc1 bc1 genotype in inter-subspecific hybrids, although the gene normally transmitted to its offspring following the Mendelian Law in intra-subspecific hybrids. In a combination of Kamairazu//Ketan Nangka/Kamairazu,an increased frequency of bc1 bc1 in F1, normal segregation in F2, and increased and decreased frequency in a few F3 and F4 lines were observed. In a cross of IR36/Kamairazu, decreased frequency in F2, both normal and decreased segregations in F3 and F4, and a few lines of increased ratio in F4 were found. In F2 of Ketan Nangka/IR36//Kamairazu, increased and decreased and normal segregations were all observed. There was no significant correlation between the frequency of bc1 bc1 and pollen fertility. It implied that distorted segregation of bc1 was caused by selective fertilization of male gametes, which were governed by gametophyte genes of ga2, ga3 and ga14 on chromosome 3.

  2. Phenology, sterility and inheritance of two environment genic male sterile (EGMS) lines for hybrid rice.

    Science.gov (United States)

    El-Namaky, R; van Oort, P A J

    2017-12-01

    There is still limited quantitative understanding of how environmental factors affect sterility of Environment-conditioned genic male sterility (EGMS) lines. A model was developed for this purpose and tested based on experimental data from Ndiaye (Senegal) in 2013-2015. For the two EGMS lines tested here, it was not clear if one or more recessive gene(s) were causing male sterility. This was tested by studying sterility segregation of the F2 populations. Daylength (photoperiod) and minimum temperatures during the period from panicle initiation to flowering had significant effects on male sterility. Results clearly showed that only one recessive gene was involved in causing male sterility. The model was applied to determine the set of sowing dates of two different EGMS lines such that both would flower at the same time the pollen would be completely sterile. In the same time the local popular variety (Sahel 108, the male pollen donor) being sufficiently fertile to produce the hybrid seeds. The model was applied to investigate the viability of the two line breeding system in the same location with climate change (+2oC) and in two other potential locations: in M'Be in Ivory Coast and in the Nile delta in Egypt. Apart from giving new insights in the relation between environment and EGMS, this study shows that these insights can be used to assess safe sowing windows and assess the suitability of sterility and fertility period of different environments for a two line hybrid rice production system.

  3. Avaliação de cultivares e híbridos de bananeira no recôncavo baiano Evaluation of banana cultivars and hybrids in northeastern Bahia

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    Marcelo Bezerra Lima

    2005-06-01

    Full Text Available O programa de melhoramento genético de bananeira da Embrapa Mandioca e Fruticultura Tropical visa desenvolver e selecionar novas cultivares de bananeira com alta produtividade, bom sabor dos frutos e que apresentem resistência às principais doenças. Objetivou-se com este trabalho avaliar cultivares e híbridos de bananeira visando a identificação de genótipos superiores em produtividade e resistência a doenças. Foram avaliados os híbridos da cv. Gros Michel (Calipso, Bucaneiro e Ambrosia; da cv.Yangambi (YB42-21 e YB42-17; da cv. Prata (ST42-08 e ST12-31 e de Prata-Anã (SH3640 e as cultivares Pacovan e Nanicão. As características utilizadas para as avaliações foram: altura da planta (m; diâmetro do pseudocaule (cm; número de folhas vivas na floração; número de folhas vivas na colheita; número de frutos por cacho; peso do cacho (kg; peso médio de frutos (g; comprimento do fruto (cm; diâmetro do fruto (cm; espessura da casca (mm; número de dias do plantio à floração e número de dias do plantio à colheita. Usou-se o delineamento em blocos casualizados com 10 tratamentos, cinco repetições e seis touceiras por parcela, espaçadas de 2,00 m x 3,00 m. Os híbridos avaliados apresentaram características agronômicas iguais ou superiores as cultivares que lhes deram origem. Os melhores híbridos de 'Prata', 'Yangambi' e 'Gros Michel' foram respectivamente, ST12-31, YB42-21 e Bucaneiro.The banana genetic breeding program at Embrapa Cassava and Tropical Fruits aims to develop and select new banana varieties with high productivity, good fruit flavor and resistance to most banana diseases. The objective of this work was to evaluate banana cultivars and hybrids in order to identify superior genotypes for productivity and disease resistance. The following characteristics were evaluated: plant height (cm; pseudostem diameter (cm; number of living leaves during flowering; and at harvest number of fingers per bunch; bunch weight

  4. Evolvement of transgenic male-sterility and fertility-restoration system in rice for production of hybrid varieties.

    Science.gov (United States)

    Rao, Gundra Sivakrishna; Deveshwar, Priyanka; Sharma, Malini; Kapoor, Sanjay; Rao, Khareedu Venkateswara

    2018-01-01

    We have developed a unique male-sterility and fertility-restoration system in rice by combining Brassica napus cysteine-protease gene (BnCysP1) with anther-specific P12 promoter of rice for facilitating production of hybrid varieties. In diverse crop plants, male-sterility has been exploited as a useful approach for production of hybrid varieties to harness the benefits of hybrid vigour. The promoter region of Os12bglu38 gene of rice has been isolated from the developing panicles and was designated as P12. The promoter was fused with gusA reporter gene and was expressed in Arabidopsis and rice systems. Transgenic plants exhibited GUS activity in tapetal cells and pollen of the developing anthers indicating anther/pollen-specific expression of the promoter. For engineering nuclear male sterility, the coding region of Brassica napus cysteine protease1 (BnCysP1) was isolated from developing seeds and fused to P12 promoter. Transgenic rice plants obtained with P12-BnCysP1 failed to produce functional pollen grains. The F 1 seeds obtained from BnCysP1 male-sterile plants and untransformed controls showed 1:1 (tolerant:sensitive) ratio when germinated on the MS medium supplemented with phosphinothricin (5 mg/l), confirming that the male sterility has been successfully engineered in rice. For male fertility restoration, transgenic rice plants carrying BnCysP1Si silencing system were developed. The pollination of BnCysP1 male-sterile (female-fertile) plants with BnCysP1Si pollen resulted in normal grain filling. The F 1 seeds of BnCysP1 × BnCysP1Si when germinated on the MS basal medium containing PPT (5 mg/l) and hygromycin (70 mg/l) exhibited 1:1 (tolerant:sensitive) ratio and the tolerant plants invariably showed normal grain filling. The overall results clearly suggest that the customized male-sterility & fertility-restoration system can be exploited for quality hybrid seed production in various crops.

  5. Yield and tillering response of super hybrid rice Liangyoupeijiu to tillage and establishment methods

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    M.A. Badshah

    2014-02-01

    Full Text Available Tillering is an important agronomic trait for rice grain production. To evaluate yield and tillering response, Liangyoupeijiu (super hybrid rice was grown in Hunan, China during 2011–2012 under different methods of tillage (conventional and no-tillage system and crop establishment methods (transplanting at a spacing of 20 cm × 20 cm with one seedling per hill and direct seeding at a seeding rate of 22.5 kg ha− 1. Our results revealed that, at maximum tillering (Max. and at maturity (MA stages, direct seeding (DS resulted in 22% more tillers than transplanting (TP irrespective of tillage system. Tiller mortality reached a peak between panicle initiation (PI and booting (BT stages, and was 16% higher under conventional tillage (CT than under no-tillage (NT. Transplanting required 29% more time for the completion of tillering and less for DS. Tillering rate was 43% higher in DS than TP under either CT or NT. There was a positive correlation between panicle number per m2 and maximum tiller number per m2, but not panicle-bearing tiller rate. The panicle bearing tiller rate was higher under DS than TP and higher under NT than CT. Tiller dry weight gradually increased up to heading (HD stage, and was 14% higher under TP than DS. Leaf area (cm2 tiller− 1 gradually increased from Max. to HD stage and then decreased by 34% in conventional tillage transplanting (CTTP and 45% in no-tillage transplanting (NTTP from 12DAH–24DAH (days after heading, but was similar (35% under DS under either CT or NT. Grain yield was higher under CTTP owing to the larger sink size (heavier panicle, more spikelets in per cm length of panicle than under DS.

  6. Variation in the Abundance of OsHAK1 Transcript Underlies the Differential Salinity Tolerance of an indica and a japonica Rice Cultivar

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    Guang Chen

    2018-01-01

    Full Text Available Salinity imposes a major constraint over the productivity of rice. A set of chromosome segment substitution lines (CSSLs, derived from a cross between the japonica type cultivar (cv. Nipponbare (salinity sensitive and the indica type cv. 9311 (moderately tolerant, was scored using a hydroponics system for their salinity tolerance at the seedling stage. Two of the CSSLs, which share a ∼1.2 Mbp stretch of chromosome 4 derived from cv. Nipponbare, were as sensitive to the stress as cv. Nipponbare itself. Fine mapping based on an F2 population bred from a backcross between one of these CSSLs and cv. 9311 narrowed this region to 95 Kbp, within which only one gene (OsHAK1 exhibited a differential (lower transcript abundance in cv. Nipponbare and the two CSSLs compared to in cv. 9311. The gene was up-regulated by exposure to salinity stress both in the root and the shoot, while a knockout mutant proved to be more salinity sensitive than its wild type with respect to its growth at both the vegetative and reproductive stages. Seedlings over-expressing OsHAK1 were more tolerant than wild type, displaying a superior photosynthetic rate, a higher leaf chlorophyll content, an enhanced accumulation of proline and a reduced level of lipid peroxidation. At the transcriptome level, the over-expression of OsHAK1 stimulated a number of stress-responsive genes as well as four genes known to be involved in Na+ homeostasis and the salinity response (OsHKT1;5, OsSOS1, OsLti6a and OsLti6b. When the stress was applied at booting through to maturity, the OsHAK1 over-expressors out-yielded wild type by 25%, and no negative pleiotropic effects were expressed in plants gown under non-saline conditions. The level of expression of OsHAK1 was correlated with Na+/K+ homeostasis, which implies that the gene should be explored a target for molecular approaches to the improvement of salinity tolerance in rice.

  7. Impact of mutation breeding in rice. A review

    Energy Technology Data Exchange (ETDEWEB)

    Rutger, J N [Department of Agriculture, Stoneville, MS (United States). Agricultural Research Service

    1992-07-01

    More cultivars have been developed in rice through the use of mutation breeding than in any other crop. Direct releases of mutants as cultivars began some 30 years ago, and now total 198 cultivars. During the last 20 years, increasing use has been made of induced mutants in cross-breeding programs, leading to 80 additional cultivars. Principal improvements through mutation breeding have been earlier maturity, short stature, and grain character modifications. Rice has been a popular subject of mutagenesis because it is the world`s leading food crop, has diploid inheritance, and is highly self-pollinated. In recent years induced mutation has been exploited to develop breeding tool mutants, which are defined as mutants that in themselves may not have direct agronomic application but may be useful genetic tools for crop improvement. Examples include the eui gene, hull colour mutants, normal genetic male steriles, and environmentally sensitive genetic male steriles. The environmentally sensitive genetic male steriles, especially those in which male sterility can be turned on or off by different photoperiod lengths, show promise for simplifying hybrid rice seed production both in China and the USA. Future applications of mutation in rice include induction of unusual endosperm starch types, plant types with fewer but more productive tillers, dominant dwarfs, dominant genetic male steriles, extremely early maturing mutants, nutritional mutants, and in vitro-derived mutants for tolerance to herbicides or other growth stresses. Refs, 4 figs, 2 tabs.

  8. Evaluation of interspecific hybrids and cultivars of Brachiaria spp. submitted to sourcers and levels of nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Márcia Atauri Cardelli Lucena

    2012-12-01

    evaluated were positively influenced by N fertilization, which can alter growth patterns and canopy structure. The hybrids H69 and H12 showed structural features in relation to all variables evaluated that positively validate as options for pasture. The ammonium nitrate was more effective than urea for dry matter production in hybrids H69 and H12 in the first cut, and for regrowth of cultivars Piata and Marandu. The results showed that nitrogen is a good tool which in turn contributes positively to increases the growth-related variables, such as dry matter (total, leaves and pseudostems. The hybrids H69 and H12 showed morphological, structural features and production of dry matter that validate them as positive options for pasture use.

  9. Hybridization study of wild rice Oryza glumaepatula with varieties of cultivated rice (O. sativa) and wild (O. grandiglumis)

    International Nuclear Information System (INIS)

    Villalobos Cascante, Eddier

    2015-01-01

    The process of interspecific hybridization of the wild species O. glumaepatula is studied with commercial varieties of the species O. sativa and O. grandiglumis, by morphological evaluation and hybrid flow cytometry. Hybrid plants were evaluated of cross between O. glumaepatula, located in the wetlands of Rio Medio Queso and two varieties of O. sativa, Puita Inta and CFX 18 resistant to a herbicide. The technique of Polymerase Chain Reaction Allele Specifies Oligonucleotide (PCR-ASO) was used to detect allelic mutations in the ALS gene conferring herbicide resistance, and it is confirmed the hybrid nature of the plants obtained at crossings. 68 hybrids were obtained: O. glumaepatula x P. Inta, 21 hybrids P. Inta x O. glumaepatula, 4 hybrids O. glumaepatula x CFX-18 and 15 hybrids CFX-18 x O. glumaepatula. 10 morphological descriptors of the genus Oryza were evaluated and determined that are indifferent to the direction and type of crossing, the hybrids resemble to the wild species O. glumaepatula for characters: height, panicle length and ligule length. All hybrids have showed similarity to commercial varieties in flag leaf length. Other characters evaluated in the hybrids have presented maternal effect, heterosis and intermediate values. The protocol of flow cytometry (FCM) is standardized species for Oryza genus analyzing nuclear DNA content of 106 samples of leaf tissue of wild species O. glumaepatula, O. grandiglumis; whose average has been of 0.73 picograms, and natural hybrids product of the cross of these species. The result has been intermediate compared with O. grandiglumis and O. glumaepatula that have made available to 1.0 picograms and 0.50 of DNA respectively. The molecular nature of the hybrids was confirmed in this way. (author) [es

  10. Energy use pattern in rice production: A case study from Mazandaran province, Iran

    International Nuclear Information System (INIS)

    AghaAlikhani, M.; Kazemi-Poshtmasari, H.; Habibzadeh, F.

    2013-01-01

    Highlights: ► We compare the energy use efficiency in rice production for traditional and mechanized system. ► Since farmers growing native, high yield and hybrid rice cultivars we have focused on mean data. ► Chemical fertilizer has the highest share in total energy inputs were followed by diesel fuel. ► Rice production in traditional system has lower output but higher EUE than mechanized system. - Abstract: Rice (Oryza sativa L.) is grown under both traditional system (TS) and mechanized system (MS) in Iran. In this study the energy consumption for rice is analyzed in Mazandaran, Northern province of Iran. The indicators are: net energy, energy use efficiency, specific energy, energy productivity, direct energy, indirect energy, renewable energy, non-renewable and total energy input. The cultivars of rice commonly grown in Iran are listed in three groups: native, high yield cultivars and hybrid cultivar. Primary data were obtained through field survey and personal interviews using questionnaires from 48 agricultural services center in Mazandaran province. Secondary data and energy equivalents were obtained from available literature using collected data of the production period of 2007–2008. Analysis of date showed that averagely diesel fuel had the highest share within the total energy inputs, followed by chemical fertilizer in rice production in both TS and MS. Energy use efficiency was calculated as 1.72 in TS and 1.63 in MS. Total energy consumption in rice production were 71,092.26 MJ/ha (TS) and 79,460.33 MJ/ha (MS). In general, there were not significant changes regarding the human labor and chemicals in tow systems

  11. Viabilidade de uso do híbrido Hawaii 7996 como porta-enxerto de cultivares comerciais de tomate Potential of Hawaii 7996 hybrid as rootstock for tomato cultivars

    Directory of Open Access Journals (Sweden)

    Suane Coutinho Cardoso

    2006-01-01

    Full Text Available A técnica de enxertia é utilizada em algumas hortaliças, principalmente em áreas infestadas, para atribuir resistência a patógenos do solo, minimizando as perdas de produção de cultivares suscetíveis. Este trabalho teve como objetivo avaliar o desenvolvimento e a produtividade de plantas de tomateiro enxertadas em híbrido, tido como resistente a Ralstonia solanacearum, em comparação a pés-francos. O experimento foi desenvolvido em viveiro (produção de mudas e enxertia e em céu aberto, no município de Cruz das Almas, Bahia, no período de outubro de 2003 a fevereiro de 2004. Utilizou-se o método de enxertia de fenda cheia, com o híbrido 'Hawaii 7996' como porta-enxerto e as cultivares Santa Clara, Santa Cruz Kada e Débora Plus, suscetíveis a R. solanacearum, como enxerto. O delineamento experimental foi em blocos ao acaso, com seis tratamentos (3 enxertados e 3 pés-francos, 5 repetições e 6 plantas por parcela útil. Avaliaram-se os caracteres: diâmetro do caule, altura da planta e da primeira inflorescência, distância entre inflorescências e produtividade comercial de frutos. O desenvolvimento das plantas, a produção total e a massa média dos frutos foram semelhantes para os tratamentos enxertados em relação a seus respectivos pés-francos e não houve incompatibilidade entre porta-enxerto e enxerto. A cultivar Santa Cruz Kada foi mais sensível às condições agroecológicas do município de Cruz das Almas, refletindo negativamente na produção e no peso médio dos frutos. Observou-se na enxertia com o híbrido 'Hawaii 7996' potencial para viabilizar a produção de tomateiros comerciais suscetíveis à murcha bacteriana, em áreas infestadas com R. solanacearum.Grafts have been used in horticultural crops, to overcome soilborne plant pathogens, and thus minimize yield losses of susceptible cultivars. This work aimed at to evaluate growth and yield of tomato plants grafted on to a hybrid resistant to Ralstonia

  12. Genomic diversity among Basmati rice ( Oryza sativa L) mutants ...

    African Journals Online (AJOL)

    Mutation breeding can be considered successful in obtaining new cultivars and broadening the genetic base of rice crop. In order to obtain new varieties of rice with improved agronomic and grain characteristics, gamma radiation (60Co) has been used to generate novel mutants of the Basmati rice. In this study rice cultivars ...

  13. Genotypic and environmental variation in cadmium, chromium, lead and copper in rice and approaches for reducing the accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Fangbin; Wang, Runfeng [Institute of Crop Science, Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058 (China); Cheng, Wangda [Jiaxing Academy of Agricultural Sciences, Jiaxing 314016 (China); Zeng, Fanrong; Ahmed, Imrul Mosaddek; Hu, Xinna; Zhang, Guoping [Institute of Crop Science, Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058 (China); Wu, Feibo, E-mail: wufeibo@zju.edu.cn [Institute of Crop Science, Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058 (China)

    2014-10-15

    The field scale trials revealed significant genotypic and environmental differences in grain heavy metal (HM) concentrations of 158 newly developed rice varieties grown in twelve locations of Zhejiang province of China. Grain Pb and Cd contents in 5.3% and 0.4% samples, respectively, were above the maximum permissible concentration (MPC); none of samples had Cr/Cu exceeding MPC. Stepwise multiple linear regression analysis estimated soil HM critical levels for safe rice production. Low grain HM accumulation cultivars such as Xiushui817, Jiayou08-1 and Chunyou689 were recommended as suitable cultivars for planting in slight/medium HM contaminated soils. The alleviating regulator (AR) of (NH{sub 4}){sub 2}SO{sub 4} as N fertilizer coupled with foliar spray of a mixture containing glutathione (GSH), Si, Zn and Se significantly decreased grain Cd, Cr, Cu and Pb concentrations grown in HM contaminated fields with no effect on yield, indicating a promising measurement for further reducing grain HM content to guarantee safe food production. - Highlights: • Field trials evaluated situation of grain HM in main rice growing areas of Zhejiang. • Forecasting index system to predict rice grain HM concentration was achieved. • Hybrid rice holds higher grain Cd concentration than conventional cultivars. • Low grain HM accumulation rice cultivars were successfully identified. • Developed alleviating regulator which effectively reduced grain toxic HM.

  14. Genotypic and environmental variation in cadmium, chromium, lead and copper in rice and approaches for reducing the accumulation

    International Nuclear Information System (INIS)

    Cao, Fangbin; Wang, Runfeng; Cheng, Wangda; Zeng, Fanrong; Ahmed, Imrul Mosaddek; Hu, Xinna; Zhang, Guoping; Wu, Feibo

    2014-01-01

    The field scale trials revealed significant genotypic and environmental differences in grain heavy metal (HM) concentrations of 158 newly developed rice varieties grown in twelve locations of Zhejiang province of China. Grain Pb and Cd contents in 5.3% and 0.4% samples, respectively, were above the maximum permissible concentration (MPC); none of samples had Cr/Cu exceeding MPC. Stepwise multiple linear regression analysis estimated soil HM critical levels for safe rice production. Low grain HM accumulation cultivars such as Xiushui817, Jiayou08-1 and Chunyou689 were recommended as suitable cultivars for planting in slight/medium HM contaminated soils. The alleviating regulator (AR) of (NH 4 ) 2 SO 4 as N fertilizer coupled with foliar spray of a mixture containing glutathione (GSH), Si, Zn and Se significantly decreased grain Cd, Cr, Cu and Pb concentrations grown in HM contaminated fields with no effect on yield, indicating a promising measurement for further reducing grain HM content to guarantee safe food production. - Highlights: • Field trials evaluated situation of grain HM in main rice growing areas of Zhejiang. • Forecasting index system to predict rice grain HM concentration was achieved. • Hybrid rice holds higher grain Cd concentration than conventional cultivars. • Low grain HM accumulation rice cultivars were successfully identified. • Developed alleviating regulator which effectively reduced grain toxic HM

  15. Produção de matéria seca, teor e acúmulo de silício em cultivares de arroz sob doses de silício Dry matter production, content and accumulation of silicon in cultivars of rice (Oryza sativa L. under levels of silicon

    Directory of Open Access Journals (Sweden)

    Leilson Antônio de Faria Júnior

    2009-08-01

    Full Text Available O efeito do silício (Si na produção de matéria seca de arroz, teor e acúmulo de Si foi avaliado sob condições de casa-de-vegetação. O delineamento experimental foi o inteiramente casualizado em esquema fatorial 5 x 2 com 4 repetições. Os tratamentos foram 5 doses de Si (0; 0,25; 0,50; 0,75 e 1,00 g dm-3 e 2 cultivares de arroz (Conai e Curinga. A aplicação de Si não afetou os componentes de crescimento e produção, com exceção da matéria seca de raiz. Houve um acréscimo da matéria seca de raiz sob aplicação de Si com uma produção máxima de 33,57 g vaso-1 na dose ajustada de 0,38 g dm-3 de Si. O acúmulo e os teores de Si variaram entre os cultivares, os quais responderam de forma linear ao aumento das doses de Si. Já para o acúmulo de Si na parte aérea não houve diferenças significativas entre cultivares.The effect of silicon (Si application on dry matter production of rice, as well as on the content and accumulation of silicon was evaluated under greenhouse conditions. The experimental design was a completely randomized design arranged in a 5 x 2 factorial structure with four replicates. The treatments consisted of a combination of five Si levels (0, 0.25, 0.50, 0.75, and 1.00 g dm-3 and two rice cultivars (Conai and Curinga. The Si application did not affect the growth and production components except the root dry matter. There was an increase in the root dry matter under Si application with a maximum production of 33.57 g pot-1 in the dose of 0.38 g dm-3 Si. The content and accumulation of Si varied between the cultivars, increasing linearly with the Si levels, except for Si accumulated in the shoot, where no significant differences were observed between the cultivars.

  16. Investigation of Genetic Distance among Parental Lines of Hybrid Rice Based on Cluster Analysis of Morphological Traits

    Directory of Open Access Journals (Sweden)

    A. Baluch-Zehi

    2013-06-01

    Full Text Available conditions. Thus, these varieties could be suitable option for yield increase and an effective step toward food security. Selection of parental lines has essential role in developing ideal combinations. Therefore, it is essential to study the relationship and genetic diversity among parental lines in hybrid rice. Sixteen hybrid rice parental lines including 6 restorer lines (Poya, Sepidrud, Pajohesh, R2, R9 and IR50 and 5 CMS lines (Neda, Nemat, Dasht, Champa and Amol 3 with their 5 maintainers were studied at Research Farm of Sari Agricultural Sciences and Natural Resources University during 2011. Analysis of variance showed significant variations for all of the studied traits, which shows great diversity among the genotypes. The number of fertile tillers and length to width ratio of grain showed positive and significant correlation with yield. But, grain width showed negative and significant correlation with yield. Results of principal component analysis revealed that 3 components explained 75.64% of the total variations. Cluster analysis at 15 genetic distance criteria grouped genotypes in 4 clusters. In exploration of heterosis phenomenon, parents must be far away from each other. So, the results of this study suggested crosses between CMS lines of Neda A, Nemat A and Champa A with each of restorer lines R9, R2, IR50 and Poya for experimental hybrid seed production.

  17. Reinforcement of natural rubber hybrid composites based on marble sludge/Silica and marble sludge/rice husk derived silica

    Directory of Open Access Journals (Sweden)

    Khalil Ahmed

    2014-03-01

    Full Text Available A research has been carried out to develop natural rubber (NR hybrid composites reinforced with marble sludge (MS/Silica and MS/rice husk derived silica (RHS. The primary aim of this development is to scrutinize the cure characteristics, mechanical and swelling properties of such hybrid composite. The use of both industrial and agricultural waste such as marble sludge and rice husk derived silica has the primary advantage of being eco-friendly, low cost and easily available as compared to other expensive fillers. The results from this study showed that the performance of NR hybrid composites with MS/Silica and MS/RHS as fillers is extremely better in mechanical and swelling properties as compared with the case where MS used as single filler. The study suggests that the use of recently developed silica and marble sludge as industrial and agricultural waste is accomplished to provide a probable cost effective, industrially prospective, and attractive replacement to the in general purpose used fillers like china clay, calcium carbonate, and talc.

  18. Development of Elite BPH-Resistant Wide-Spectrum Restorer Lines for Three and Two Line Hybrid Rice.

    Science.gov (United States)

    Fan, Fengfeng; Li, Nengwu; Chen, Yunping; Liu, Xingdan; Sun, Heng; Wang, Jie; He, Guangcun; Zhu, Yingguo; Li, Shaoqing

    2017-01-01

    Hybrid rice has contributed significantly to the world food security. Breeding of elite high-yield, strong-resistant broad-spectrum restorer line is an important strategy for hybrid rice in commercial breeding programs. Here, we developed three elite brown planthopper (BPH)-resistant wide-spectrum restorer lines by pyramiding big-panicle gene Gn8.1 , BPH-resistant genes Bph6 and Bph9 , fertility restorer genes Rf3, Rf4, Rf5 , and Rf6 through molecular marker assisted selection. Resistance analysis revealed that the newly developed restorer lines showed stronger BPH-resistance than any of the single-gene donor parent Luoyang-6 and Luoyang-9. Moreover, the three new restorer lines had broad spectrum recovery capabilities for Honglian CMS, Wild abortive CMS and two-line GMS sterile lines, and higher grain yields than that of the recurrent parent 9,311 under nature field conditions. Importantly, the hybrid crosses also showed good performance for grain yield and BPH-resistance. Thus, the development of elite BPH-resistant wide-spectrum restorer lines has a promising future for breeding of broad spectrum BPH-resistant high-yield varieties.

  19. Genetic characterization and fine mapping of S25, a hybrid male sterility gene, on rice chromosome 12.

    Science.gov (United States)

    Kubo, Takahiko; Yoshimura, Atsushi; Kurata, Nori

    2018-02-10

    Hybrid male sterility genes are important factors in creating postzygotic reproductive isolation barriers in plants. One such gene, S25, is known to cause severe transmission ratio distortion in inter-subspecific progeny of cultivated rice Oryza sativa ssp. indica and japonica. To further characterize the S25 gene, we fine-mapped and genetically characterized the S25 gene using near-isogenic lines with reciprocal genetic backgrounds. We mapped the S25 locus within the 0.67-1.02 Mb region on rice chromosome 12. Further genetic analyses revealed that S25 substantially reduced male fertility in the japonica background, but not in the indica background. In first-generation hybrid progeny, S25 had a milder effect than it had in the japonica background. These results suggest that the expression of S25 is epistatically regulated by at least one partially dominant gene present in the indica genome. This finding supports our previous studies showing that hybrid male sterility due to pollen killer genes results from epistatic interaction with other genes that are hidden in the genetic background.

  20. Effect of forging on mechanical properties of rice husk ash-silicon carbide reinforced Al1100 hybrid composites

    Science.gov (United States)

    Ghanaraja, S.; Gireesha, B. L.; Ravikumar, K. S.; Likith, P.

    2018-04-01

    During the past few years, material design has changed prominence to pursue light weight, environment friendliness, low cost, quality, higher service temperature, higher elastic modulus, improved wear resistance and performance. Straight monolithic materials have limitations in achieving the above decisive factors. To overcome these limitations and to convince the ever increasing demand of modern day technology, Attention has been shifted towards Metal Matrix Composites (MMC). Stir casting route is most hopeful for synthesizing discontinuous reinforcement aluminium matrix composites because of its relative simplicity and easy adaptability with all shape casting process used in metal casting industry. Hybridization of metal matrix composites is the introduction of more than one type/kind, size and shape of reinforcement during processing of composites. It is carried out to obtain synergistic properties of different reinforcements and matrix used, which may not be rea1ised in monolithic alloy or in conventional monocomposites. The present study involves synthesis of hybrid composites by addition of the desired amount of Silicon Carbide (SiC) and Rice Husk Ash (RHA) particles in to the molten Al 1100-Mg alloy through stir casting technique fallowed by hot forging of the cast composites. The influence of increasing in the wt% (3, 6, 9, 12 and 15 wt%) of SiC particles addition (3 wt% Rice husk ash kept constant) on evolution of microstructure is studied through XRD and SEM and their impact on the mechanical properties like hardness and tensile strength of the resulting forged hybrid composites has been investigated.

  1. Translocation kinetics of 14C-photosynthate in hybrid rice grown at different potassium levels

    International Nuclear Information System (INIS)

    Jiang Dean; Shen Yuwei; Xie Xuemin; Rao Lihua; Lu Qing

    1993-01-01

    The kinetics of translocation of 14 C-assimilate in hybrid rice plant was studied with 14 CO 2 fed to functional leaf at the tillering and filling stages. The result indicated that the relationship between percentage (V) of photosynthate exporting out of the source leaf or that of assimilate into sink, expanding young leaf or filling panicle, respectively,and time(t)after introducing 14 CO 2 into the leaf was extremely coincided with the regression equation : v = V (t + k)/K m + (t + k). At the tillering stage, fully extended top leaf could export 66% ∼ 79% of its photosynthate assimilated at different potassium levels, and both export potential and rate of 14 C-photosynthate in the fed leaf decreased under the low potassium (1 ppm K supplied), but the rate obviously increased in the superfluous potassium (80 ppm K supplied) in spite of slightly low exporting capacity. Main sink, the expanding young leaf on the top of stem could obtain 28% ∼ 59% of 14 C-assimilate at various potassium levels. Both the importation potential and rate were lowered with low potassium application while hastened by super-supplied potassium at the same development stage. At the filling stage, source, flag leaf, was able to export 83% ∼ 97% of its photosynthate and low potassium (5 ppm) application not only delayed the time of 14 C-photosynthate exportation but also diminished the export rate, whereas the rate was accelerated by superfluous potassium. Low potassium resulted in decrease both in the capacity and in the rate of assimilate importing into grain, nevertheless, high potassium caused decrease of percentage assimilate importing into grain and the increase of improving rate. Therefore, it was strategically considered that neither deficient nor superfluous potassium application was beneficial for assimilate transportation

  2. Evaluation of the agronomic performance of atrazine-tolerant transgenic japonica rice parental lines for utilization in hybrid seed production.

    Directory of Open Access Journals (Sweden)

    Luhua Zhang

    Full Text Available Currently, the purity of hybrid seed is a crucial limiting factor when developing hybrid japonica rice (Oryza sativa L.. To chemically control hybrid seed purity, we transferred an improved atrazine chlorohydrolase gene (atzA from Pseudomonas ADP into hybrid japonica parental lines (two maintainers, one restorer, and Nipponbare, by using Agrobacterium-mediated transformation. We subsequently selected several transgenic lines from each genotype by using PCR, RT-PCR, and germination analysis. In the presence of the investigated atrazine concentrations, particularly 150 µM atrazine, almost all of the transgenic lines produced significantly larger seedlings, with similar or higher germination percentages, than did the respective controls. Although the seedlings of transgenic lines were taller and gained more root biomass compared to the respective control plants, their growth was nevertheless inhibited by atrazine treatment compared to that without treatment. When grown in soil containing 2 mg/kg or 5 mg/kg atrazine, the transgenic lines were taller, and had higher total chlorophyll contents than did the respective controls; moreover, three of the strongest transgenic lines completely recovered after 45 days of growth. After treatment with 2 mg/kg or 5 mg/kg of atrazine, the atrazine residue remaining in the soil was 2.9-7.0% or 0.8-8.7% respectively, for transgenic lines, and 44.0-59.2% or 28.1-30.8%, respectively, for control plants. Spraying plants at the vegetative growth stage with 0.15% atrazine effectively killed control plants, but not transgenic lines. Our results indicate that transgenic atzA rice plants show tolerance to atrazine, and may be used as parental lines in future hybrid seed production.

  3. Two-line hybrid rice male sterile line 'NHR111S' with a marker of green-revertible albino leaves

    International Nuclear Information System (INIS)

    Wu Wei; Liu Xin; Shu Xiaoli; Shu Qingyao; Xia Yingwu; Wu Dianxing

    2006-01-01

    NHR111S is a new two-line male sterile line with a marker of green-revertible albino leave that was bred from in vitro mutagens is of the thermo/photoperiod-sensitive male sterile line 'Guangzhan63S' by 60 Co γ-rays. It has the same desired agronomic traits, fertility characteristics and combining ability as characteristics of the parent. It is convenient to develop leaf color marker-aided elimination strategy in the multiplication and production of hybrid rice seeds. (authors)

  4. Use of SSR markers for DNA fingerprinting and diversity analysis of Pakistani sugarcane (Saccharum spp. hybrids) cultivars

    Science.gov (United States)

    In recent years SSR markers have been used widely for genetic analysis. The objective of this study was to use an SSR-based marker system to develop the molecular fingerprints and analyze the genetic relationship of sugarcane cultivars grown in Pakistan. Twenty-one highly polymorphic SSR markers wer...

  5. Effects of shading on starch pasting characteristics of indica hybrid rice (Oryza sativa L..

    Directory of Open Access Journals (Sweden)

    Li Wang

    Full Text Available Rice is an important staple crop throughout the world, but environmental stress like low-light conditions can negatively impact crop yield and quality. Using pot experiments and field experiments, we studied the effects of shading on starch pasting viscosity and starch content with six rice varieties for three years, using the Rapid Visco Analyser to measure starch pasting viscosity. Shading at different growth stages and in different rice varieties all affected the starch pasting characteristics of rice. The effects of shading on starch pasting viscosity at middle and later growth stages were greater than those at earlier stages. Shading enhanced breakdown but reduced hold viscosity and setback at tillering-elongation stage. Most pasting parameters changed significantly with shading after elongation stage. Furthermore, the responses of different varieties to shading differed markedly. The change scope of starch pasting viscosity in Dexiang 4103 was rather small after heading, while that in IIyou 498 and Gangyou 906 was small before heading. We observed clear tendencies in peak viscosity, breakdown, and pasting temperature of the five rice varieties with shading in 2010 and 2011. Correlation analysis indicated that the rice amylose content was negatively correlated with breakdown, but was positively correlated with setback. Based on our results, IIyou 498, Gangyou 906, and Dexiang 4103 had higher shade endurance, making these varieties most suitable for high-quality rice cultivation in low-light regions.

  6. Effects of shading on starch pasting characteristics of indica hybrid rice (Oryza sativa L.).

    Science.gov (United States)

    Wang, Li; Deng, Fei; Ren, Wan-Jun; Yang, Wen-Yu

    2013-01-01

    Rice is an important staple crop throughout the world, but environmental stress like low-light conditions can negatively impact crop yield and quality. Using pot experiments and field experiments, we studied the effects of shading on starch pasting viscosity and starch content with six rice varieties for three years, using the Rapid Visco Analyser to measure starch pasting viscosity. Shading at different growth stages and in different rice varieties all affected the starch pasting characteristics of rice. The effects of shading on starch pasting viscosity at middle and later growth stages were greater than those at earlier stages. Shading enhanced breakdown but reduced hold viscosity and setback at tillering-elongation stage. Most pasting parameters changed significantly with shading after elongation stage. Furthermore, the responses of different varieties to shading differed markedly. The change scope of starch pasting viscosity in Dexiang 4103 was rather small after heading, while that in IIyou 498 and Gangyou 906 was small before heading. We observed clear tendencies in peak viscosity, breakdown, and pasting temperature of the five rice varieties with shading in 2010 and 2011. Correlation analysis indicated that the rice amylose content was negatively correlated with breakdown, but was positively correlated with setback. Based on our results, IIyou 498, Gangyou 906, and Dexiang 4103 had higher shade endurance, making these varieties most suitable for high-quality rice cultivation in low-light regions.

  7. Tissue culture-induced genetic and epigenetic alterations in rice pure-lines, F1 hybrids and polyploids.

    Science.gov (United States)

    Wang, Xiaoran; Wu, Rui; Lin, Xiuyun; Bai, Yan; Song, Congdi; Yu, Xiaoming; Xu, Chunming; Zhao, Na; Dong, Yuzhu; Liu, Bao

    2013-05-05

    Genetic and epigenetic alterations can be invoked by plant tissue culture, which may result in heritable changes in phenotypes, a phenomenon collectively termed somaclonal variation. Although extensive studies have been conducted on the molecular nature and spectrum of tissue culture-induced genomic alterations, the issue of whether and to what extent distinct plant genotypes, e.g., pure-lines, hybrids and polyploids, may respond differentially to the tissue culture condition remains poorly understood. We investigated tissue culture-induced genetic and epigenetic alterations in a set of rice genotypes including two pure-lines (different subspecies), a pair of reciprocal F1 hybrids parented by the two pure-lines, and a pair of reciprocal tetraploids resulted from the hybrids. Using two molecular markers, amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP), both genetic and DNA methylation alterations were detected in calli and regenerants from all six genotypes, but genetic alteration is more prominent than epigenetic alteration. While significant genotypic difference was observed in frequencies of both types of alterations, only genetic alteration showed distinctive features among the three types of genomes, with one hybrid (N/9) being exceptionally labile. Surprisingly, difference in genetic alteration frequencies between the pair of reciprocal F1 hybrids is much greater than that between the two pure-line subspecies. Difference also exists in the pair of reciprocal tetraploids, but is to a less extent than that between the hybrids. The steady-state transcript abundance of genes involved in DNA repair and DNA methylation was significantly altered in both calli and regenerants, and some of which were correlated with the genetic and/or epigenetic alterations. Our results, based on molecular marker analysis of ca. 1,000 genomic loci, document that genetic alteration is the major cause of somaclonal variation in rice

  8. [Effects of exogenous silicon on the pollination and fertility characteristics of hybrid rice under heat stress during anthesis].

    Science.gov (United States)

    Wu, Chen-Yang; Chen, Dan; Luo, Hai-Wei; Yao, Yi-min; Wang, Zhi-Wei; Tsutomu, Matsui; Tian, Xiao-Hai

    2013-11-01

    Taking two medium-maturing indica rice hybrids Jinyou 63 and Shanyou 63 as test materials, this paper studied the effects of applying silicon fertilizer on the flag leaf chlorophyll content, photosynthetic properties, antioxidant enzyme activities, malondialdehyde (MDA) content, pollen vigor, anther acid invertase activity, pollination, and seed-setting of hybrid rice under the heat stress during anthesis. This study was conducted in pots and under growth chamber. Soluble solution of silicon fertilizer applied as Na2SiO3 x 9H2O was sprayed on the growing plants after early jointing stage, with three times successively and at an interval of one week. The pots were then moved into growth chamber to subject to normal temperature vs. high temperature (termed as heat stress) for five days. In treatment normal temperature, the average daily temperature was set at 26.6 degrees C, and the maximum daily temperature was set at 29.4 degres C; in treatment high temperature, the average and the maximum daily temperature were set at 33.2 degrees C and 40.1 degrees C, respectively. As compared with the control, applying silicon increased the flag leaf chlorophyll content significantly, improved the net photosynthetic rate and stomatal conductance, decreased the accumulative inter- cellular CO2 concentration, improved the leaf photosynthesis, reduced the MDA content, and improved the activities of SOD, POD and CAT under heat stress. In addition, applying silicon improved the anther acid invertase activity and the pollen vigor, increased the anther basal dehiscence width, total number of pollination per stigma, germinated number, germination rate of pollen, and percentage of florets with more than 10 germinated pollen grains, decreased the percentage of florets with fewer than 20 germinated pollen grains, and thus, alleviated the fertility loss of Jinyou 63 and Shanyou 63 under heat stress by 13.4% and 14.1%, respectively. It was suggested that spraying exogenous silicon in the

  9. Profundidade da amostragem de solo e de raízes e índice de infestação de Oryzophagus oryzae (Costa Lima, 1936 (Coleoptera: Curculionidae em cultivares de arroz Sampling depth of soil and roots and Oryzophagus oryzae (Costa Lima, 1936 (Coleoptera: Curculionidae infestation index in rice cultivars

    Directory of Open Access Journals (Sweden)

    Márcio Bartz das Neves

    2011-12-01

    . Concluiu-se que, num Planossolo Háplico, amostras de solo e de raízes de arroz retiradas à profundidade de 6cm são mais apropriadas à captura e à visualização de larvas de O. oryzae, na suspensão (solo e água formada nas peneiras usadas para a sua contagem, e à obtenção de adultos desse inseto.Oryzophagus oryzae is the key insect pest in flooded rice fields in southern Brazil. Their larvae, known as rice water weevil cause significant yield losses when they cut the roots of rice plants. For the monitoring and survey of the larval population of O. oryzae, on rice fields and rice trials, respectively, are currently used standard samples of soil and roots, with 8.5cm deep and 10cm wide, blown away by submersion and shaking in a sieve with water for the counting of larvae. The visualization of larvae, especially the 1st and 2nd instars, becomes difficult in the suspension formed by the soil samples with these dimensions and the water inside the sieves. Thus, an experiment was conducted in a Typic Albaqualf soil according to the Latin square design to determine a sampling depth of soil and roots that makes possible the capture and display a larger number of larvae in a smallest possible volume of soil, in different rice cultivars. The treatments consisted of six rice cultivars ('BRS Atalanta'; 'BRS Firmeza'; 'BRS Ligeirinho'; 'BRS Querência'; 'BRS Sinuelo CL'; 'IRGA 417' and three depths (3, 6 and 9cm for removing samples of soil and roots, every 10cm diameter. In the immediate withdrawal of samples, it was announced the number of larvae. Subsequently, in periodic evaluations, it was announced the number of adults emerged from samples kept intact in plastic buckets with water depth of 13, 16 and 19cm, covered by screened mesh fabric. It was detected a significant interaction between sampling depths and the rice cultivars 'BRS Sinuelo CL' and 'BRS Querência' in the rate of infestation of larvae and adults of O. oryzae, respectively. In the case of both variables

  10. Development of new semidwarf sources for rice with different cytoplasms (CV Basmati 370 and Gloria)

    Energy Technology Data Exchange (ETDEWEB)

    Deus, J E; Suarez, E [Instituto de Investigaciones del Arroz, Bauta, Havana (Cuba); Fuentes, J L; Alvarez, A; Padron, E [Centro de Estudios Aplicados al Desarrollo Nuclear, Miramar, Playa, Havana (Cuba)

    2001-05-01

    In Cuba semidwarf rice varieties grow on 98% of the area. Virtually all carry the same Dee-geo-won-gen dwarfing gene. Also, most if not all the cultivars have the same cytoplasm. The induced mutations approach was undertaken in order to generate alternative genetic sources of dwarfing with different cytoplasms and to improve the grain quality of Cuban rice. The seeds of two varieties, Basmati 370 and Gloria, were irradiated with 200 and 300 Gy of {sup 60}Co gamma rays. In several generations of selection, progeny testing and preliminary yield tests 10 mutants (6 from Basmati 370 and 4 from Gloria), whose yields exceeded the source cultivars, have been advanced to replicated yield trials. Some of the mutant lines are also resistant to lodging and to blast (Pyricularis grisea). It is concluded the induced mutations can be used successfully to improve plant type and other agronomic traits in rice. The induced mutants will be used also in hybridization programs. (author)

  11. Development of new semidwarf sources for rice with different cytoplasms (CV Basmati 370 and Gloria)

    International Nuclear Information System (INIS)

    Deus, J.E.; Suarez, E.; Fuentes, J.L.; Alvarez, A.; Padron, E.

    2001-01-01

    In Cuba semidwarf rice varieties grow on 98% of the area. Virtually all carry the same Dee-geo-won-gen dwarfing gene. Also, most if not all the cultivars have the same cytoplasm. The induced mutations approach was undertaken in order to generate alternative genetic sources of dwarfing with different cytoplasms and to improve the grain quality of Cuban rice. The seeds of two varieties, Basmati 370 and Gloria, were irradiated with 200 and 300 Gy of 60 Co gamma rays. In several generations of selection, progeny testing and preliminary yield tests 10 mutants (6 from Basmati 370 and 4 from Gloria), whose yields exceeded the source cultivars, have been advanced to replicated yield trials. Some of the mutant lines are also resistant to lodging and to blast (Pyricularis grisea). It is concluded the induced mutations can be used successfully to improve plant type and other agronomic traits in rice. The induced mutants will be used also in hybridization programs. (author)

  12. Selection and breeding of plant cultivars to minimize cadmium accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Grant, C.A. [AAFC Brandon Research Centre, Box 1000A, R.R. 3, Brandon, MB, R7A 5Y3 (Canada)], E-mail: cgrant@agr.gc.ca; Clarke, J.M. [AAFC Semiarid Prairie Agricultural Research Centre, Swift Current, SK, S9H 3X2 (Canada); Duguid, S. [AAFC Morden Research Station, Morden, MB, R6M 1Y5 (Canada); Chaney, R.L. [USDA, ARS, Animal Manure and Byproducts Laboratory, Room 013, Building 007, BARC-West, 10300 Baltimore Avenue, Beltsville, MD 20705-2350 (United States)

    2008-02-15

    Natural variation occurs in the uptake and distribution of essential and nonessential trace elements among crop species and among cultivars within species. Such variation can be responsible for trace element deficiencies and toxicities, which in turn can affect the quality of food. Plant breeding can be an important tool to both increase the concentration of desirable trace elements and reduce that of potentially harmful trace elements such as cadmium (Cd). Selection programs for a low-Cd content of various crops, including durum wheat, sunflower, rice and soybean have been established and low-Cd durum wheat cultivars and sunflower hybrids have been developed. In durum wheat (Triticum turgidum L. var durum), low-Cd concentration is controlled by a single dominant gene. The trait is highly heritable, and incorporation of the low-Cd allele can help to reduce the average grain Cd to levels below proposed international limits. The allele for low-Cd concentration does not appear to affect major economic traits and should not cause problems when incorporated into durum cultivars. The cost of Cd selection in a breeding program is initially large both in terms of Cd determination and reduced progress towards development of other economic traits, but declines as more breeding lines in the program carry the low-Cd trait and are utilized in new crosses. Production of low-Cd crop cultivars can be used as a tool to reduce the risk of movement of Cd into the human diet.

  13. Avaliação de cultivares e híbridos de repolho no Estado do Acre Evaluation of cabbage cultivars and hybrids in the state of Acre

    Directory of Open Access Journals (Sweden)

    Francisco J. da S. Lédo

    2000-07-01

    para a comercialização, sendo considerados promissores para cultivo na época seca em Rio Branco-AC.The objective of this work was to evaluate yield and quality of two cultivars (Louco de Verão e União and nine cabbage hybrids (Caribe, Fuyutoyo, Kenzan, Master AG-325, Matsukaze, Rookie, Saikô, Sooshu and YR Park, during the dry season. The experiment was carried out at the experimental field of Embrapa Acre, in Rio Branco, Brazil, from June to October 1996, in a dark-red claysoil soil, of clay texture. Each experimental plot was made up of two lines of ten plants, distanced 0.8 m from each other and 0.4 m between plants. The experimental design was of randomized complete blocks, with three repetitions. The total yield and average head weight, format index, C/D ratio (core lenght/longitudinal diameter, head compactness, harvest cycle and percentage of heads presenting bacterial rot were evaluated. The hybrids Saikô, Fuyutoyo, Sooshu and YR Park presented the greatest total production of heads (41.8, 41.3, 39.3 and 38.7 t/ha, respectively, while 'Louco de Verão', 'Fuyutoyo', 'Saikô', 'Sooshu', 'Master', 'Caribe' and 'YR Park' had the greatest average weight per heads, with averages varying from 1,410 to 1,632 g. The hybrids YR Park and Sooshu presented flat heads and the others slightly flat heads, with format index varying from 0.90 to 0.77. For the C/D ratio, Master AG-325, Sooshu, Rookie, Saikô and Fuyutoyo hybrids and União cultivar had the smallest values, varying from 0.48 to 0.57. In relation to the head compactness, with the exception of YR Park hybrid, all the others showed good compactness. Sooshu and YR Park hybrids presented the most precocious production cycles, with harvest beginning 63 days after transplanting, and 'Rookie' the latest (91 days. Saikô and Sooshu hybrids stood out from the others, presenting heads with uniformity of weight and format, C/D ratio and compactness appropriate for marketing. They were considered promising for

  14. Effects of manganese oxide-modified biochar composites on arsenic speciation and accumulation in an indica rice (Oryza sativa L.) cultivar.

    Science.gov (United States)

    Yu, Zhihong; Qiu, Weiwen; Wang, Fei; Lei, Ming; Wang, Di; Song, Zhengguo

    2017-02-01

    A pot experiment was used to investigate arsenic (As) speciation and accumulation in rice, as well as its concentration in both heavily contaminated and moderately contaminated soils amended with manganese oxide-modified biochar composites (MBC) and biochar alone (BC). In heavily As-contaminated soil, application of BC and MBC improved the weight of above-ground part and rice root, whereas in moderately As-contaminated soil, the application of MBC and low rate BC amendment increased rice root, grain weight and the biomass of the plant. Arsenic reduction in different parts of rice grown in MBC-amended soils was greater than that in plants cultivated in BC-amended soils. Such reduction can be attributed to the oxidation of arsenite, As(III), to arsenate, As(V), by Mn-oxides, which also had a strong adsorptive capacity for As(V). MBC amended to As-contaminated soil had a positive effect on amino acids. The Fe and Mn levels in the iron-manganese plaque that formed on the rice root surface differed among the treatments. MBC addition significantly increased Mn content (p rice. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Introgression of Blast Resistance Genes (Putative Pi-b and Pi-kh) into Elite Rice Cultivar MR219 through Marker-Assisted Selection

    Science.gov (United States)

    Tanweer, Fatah A.; Rafii, Mohd Y.; Sijam, Kamaruzaman; Rahim, Harun A.; Ahmed, Fahim; Ashkani, Sadegh; Latif, Mohammad A.

    2015-01-01

    Blast is the most common biotic stress leading to the reduction of rice yield in many rice-growing areas of the world, including Malaysia. Improvement of blast resistance of rice varieties cultivated in blast endemic areas is one of the most important objectives of rice breeding programs. In this study, the marker-assisted backcrossing strategy was applied to improve the blast resistance of the most popular Malaysian rice variety MR219 by introgressing blast resistance genes from the Pongsu Seribu 2 variety. Two blast resistance genes, Pi-b and Pi-kh, were pyramided into MR219. Foreground selection coupled with stringent phenotypic selection identified 15 plants homozygous for the Pi-b and Pi-kh genes, and background selection revealed more than 95% genome recovery of MR219 in advanced blast resistant lines. Phenotypic screening against blast disease indicated that advanced homozygous blast resistant lines were strongly resistant against pathotype P7.2 in the blast disease endemic areas. The morphological, yield, grain quality, and yield-contributing characteristics were significantly similar to those of MR219. The newly developed blast resistant improved lines will retain the high adoptability of MR219 by farmers. The present results will also play an important role in sustaining the rice production of Malaysia. PMID:26734013

  16. Physiology and productivity of rice crop influenced by drought stress ...

    African Journals Online (AJOL)

    Rice is sensitive to moisture stress and in view of the water scarcity in the coming years, it is imperative to evaluate the performance of rice cultivar under moisture deficit. The present study aimed to evaluate the physiological responses of two rice cultivars under drought stress induced at panicle initiation and soft dough ...

  17. significance of rice sheath photosynthesis: yield determination by c ...

    African Journals Online (AJOL)

    ACSS

    1State Key Laboratory of Hybrid Rice, Hunan Hybrid Rice Research Center, Changsha 410125, P.R. China. 2School of ... for contribution rates of sheath photosynthesis to economical yield. ..... related processes during ripening in rice plants.

  18. A comprehensive crop genome research project: the Superhybrid Rice Genome Project in China.

    Science.gov (United States)

    Yu, Jun; Wong, Gane Ka-Shu; Liu, Siqi; Wang, Jian; Yang, Huanming

    2007-06-29

    In May 2000, the Beijing Institute of Genomics formally announced the launch of a comprehensive crop genome research project on rice genomics, the Chinese Superhybrid Rice Genome Project. SRGP is not simply a sequencing project targeted to a single rice (Oryza sativa L.) genome, but a full-swing research effort with an ultimate goal of providing inclusive basic genomic information and molecular tools not only to understand biology of the rice, both as an important crop species and a model organism of cereals, but also to focus on a popular superhybrid rice landrace, LYP9. We have completed the first phase of SRGP and provide the rice research community with a finished genome sequence of an indica variety, 93-11 (the paternal cultivar of LYP9), together with ample data on subspecific (between subspecies) polymorphisms, transcriptomes and proteomes, useful for within-species comparative studies. In the second phase, we have acquired the genome sequence of the maternal cultivar, PA64S, together with the detailed catalogues of genes uniquely expressed in the parental cultivars and the hybrid as well as allele-specific markers that distinguish parental alleles. Although SRGP in China is not an open-ended research programme, it has been designed to pave a way for future plant genomics research and application, such as to interrogate fundamentals of plant biology, including genome duplication, polyploidy and hybrid vigour, as well as to provide genetic tools for crop breeding and to carry along a social burden-leading a fight against the world's hunger. It began with genomics, the newly developed and industry-scale research field, and from the world's most populous country. In this review, we summarize our scientific goals and noteworthy discoveries that exploit new territories of systematic investigations on basic and applied biology of rice and other major cereal crops.

  19. Behavior of occurrence of Banana Streak virus in in vitro propagated plants from cultivars of Musa hybrids FHIA-20 and FHIA-21

    Directory of Open Access Journals (Sweden)

    Orelvis Portal

    2004-07-01

    Full Text Available The losses taken place by the black and yellow Sigatoka have impelled the introduction to the country of the tetraploid hybrids from FHIA, however, at the present time, the high incidence of Banana Streak Virus in these hybrids is well known. To evaluate the effect of the micropropagatión process, on the fluctuations of the viral concentration in the tissue, they were introduced to the in vitro propagation positive and negative plants serologically tested of the cultivars FHIA 20 and 21, previously indexed in field (DAS-ELISA, later on they passed to phase of adaptation to evaluate the derived results of the diagnosis tests carried out after 3-6 months of transplanted. As a result of the DAS-ELISA carried out to the plants in phase of adaptation (37 22.2 % of the negative plants, indexed in field, was positive, while 68.4 % of the positive plants, indexed in field, was negative, in both cases all the plants were positive to the diagnosis for PCR. In some cases, given the implication of the obtained results, was used the ISEM as technique of diagnostic, for the corroboration of the same ones. Key Words: badnavirus, diagnostic, in vitro culture, Musa

  20. Effects of Surface Charge and Functional Groups on the Adsorption and Binding Forms of Cu and Cd on Roots of indica and japonica Rice Cultivars

    Directory of Open Access Journals (Sweden)

    Zhao-Dong Liu

    2017-08-01

    Full Text Available This work was designed to understand the mechanisms of adsorption of copper (Cu and cadmium (Cd on roots of indica and japonica varieties of rice. Six varieties each of indica and japonica rice were grown in hydroponics and the chemical properties of the root surface were analyzed, including surface charges and functional groups (-COO- groups as measured by the streaming potential and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR. Binding forms of heavy metals adsorbed on rice roots were identified using sequential extraction methods. In rice roots exposed to Cu and Cd solutions, Cu existed mainly in both exchangeable and complexed forms, whereas Cd existed mainly in the exchangeable form. The amounts of exchangeable Cu and Cd and total adsorbed metal cations on the roots of indica varieties were significantly greater than those on the roots of japonica varieties, and the higher negative charges and the larger number of functional groups on the roots of indica varieties were responsible for their higher adsorption capacity and greater binding strength for Cu and Cd. Surface charge and functional groups on roots play an important role in the adsorption of Cu and Cd on the rice roots.

  1. Changes in Lignin and Polysaccharide Components in 13 Cultivars of Rice Straw following Dilute Acid Pretreatment as Studied by Solution-State 2D 1H-13C NMR

    Science.gov (United States)

    Teramura, Hiroshi; Sasaki, Kengo; Oshima, Tomoko; Aikawa, Shimpei; Matsuda, Fumio; Okamoto, Mami; Shirai, Tomokazu; Kawaguchi, Hideo; Ogino, Chiaki; Yamasaki, Masanori; Kikuchi, Jun; Kondo, Akihiko

    2015-01-01

    A renewable raw material, rice straw is pretreated for biorefinery usage. Solution-state two-dimensional (2D) 1H-13 C hetero-nuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy, was used to analyze 13 cultivars of rice straw before and after dilute acid pretreatment, to characterize general changes in the lignin and polysaccharide components. Intensities of most (15 of 16) peaks related to lignin aromatic regions, such as p-coumarate, guaiacyl, syringyl, p-hydroxyphenyl, and cinnamyl alcohol, and methoxyl, increased or remained unchanged after pretreatment. In contrast, intensities of most (11 of 13) peaks related to lignin aliphatic linkages or ferulate decreased. Decreased heterogeneity in the intensities of three peaks related to cellulose components in acid-insoluble residues resulted in similar glucose yield (0.45–0.59 g/g-dry biomass). Starch-derived components showed positive correlations (r = 0.71 to 0.96) with glucose, 5-hydroxymethylfurfural (5-HMF), and formate concentrations in the liquid hydrolysates, and negative correlations (r = –0.95 to –0.97) with xylose concentration and acid-insoluble residue yield. These results showed the fate of lignin and polysaccharide components by pretreatment, suggesting that lignin aromatic regions and cellulose components were retained in the acid insoluble residues and starch-derived components were transformed into glucose, 5-HMF, and formate in the liquid hydrolysate. PMID:26083431

  2. Dolce Vita in the Rice Paddy - Characterization of weedy rice groups in Northern Italy and investigation of their evolutionary origins

    OpenAIRE

    Grimm, Annabelle

    2014-01-01

    The thesis deals with the topic of the invasive rice form called weedy rice or red rice. Studies focused on the geographical area of Italy. Different populations of weedy rice in Italy were genetically characterized. The evolutionary origins of different weedy rice groups were investigated using molecular, morphological and physiological methods. Invasion of wild rice as well as de-domestication of cultivars could be identified as evolutionary sources of weedy rice in Northern Italy.

  3. Períodos de interferência das plantas daninhas na cultura do arroz de terras altas. II - cultivar Caiapó Interference periods of weeds in the upland rice - Caiapó variety

    Directory of Open Access Journals (Sweden)

    Maria Rosangela Malheiros Silva

    2009-01-01

    Full Text Available Os experimentos foram desenvolvidos nos anos agrícolas 2003/2004 e 2004/2005, em área experimental da Universidade Estadual Paulista, Campus de Jaboticabal (SP, com o objetivo de se determinarem os períodos de interferência das plantas daninhas na cultura do arroz de terras altas, cultivar Caiapó. O delineamento experimental foi em blocos ao acaso com quatro repetições e 16 tratamentos. Os tratamentos foram constituídos por períodos crescentes de controle ou de convivência das plantas daninhas após a emergência da cultura: 0-10, 0-20, 0-30, 0-40, 0-50, 0-60, 0-70 dias e 0-colheita. Nos dois anos, as famílias predominantes eram Poaceae, Asteraceae, Amaranthaceae e Malvaceae e as principais plantas daninhas presentes foram: Cyperus rotundus L., Cenchrus echinatus L., Digitaria spp Heist., Echinochloa crus-galli (L. P. Beauv., Brachiaria decumbens Stapf., Eleusine indica Gaertn e Alternanthera tenella Colla. A cultivar de arroz de terras altas Caiapó deve ser mantida sem plantas daninhas nos 30 dias após a emergência.The experiments were carried out in two growing seasons (2003/04 and 2004/05 in an experimental area at São Paulo State University - UNESP, Jaboticabal Campus, to evaluate the weed interference periods on the upland Caiapó rice variety. The experimental design was randomized blocks with 4 replicates and 16 treatments. The treatments consisted of increasing periods of control or coexistence after emergence of the culture: 0-10; 0-20; 0-30; 0-40; 0-50; 0-60; 0-70 days; 0-harvest. The predominant families were Poaceae, Asteraceae, Amaranthaceae and Malvaceae, and the main weeds present were Cyperus rotundus L., Cenchrus echinatus L., Digitaria spp Heist., Echinochloa crus-galli (L. P. Beauv., Brachiaria decumbens Stapf., Eleusine indica Gaertn e Alternanthera tenella Colla for both years. The upland rice cultivar Caiapó is to be kept free of weeds for 30 days after emergence.

  4. Duplication and Loss of Function of Genes Encoding RNA Polymerase III Subunit C4 Causes Hybrid Incompatibility in Rice

    Directory of Open Access Journals (Sweden)

    Giao Ngoc Nguyen

    2017-08-01

    Full Text Available Reproductive barriers are commonly observed in both animals and plants, in which they maintain species integrity and contribute to speciation. This report shows that a combination of loss-of-function alleles at two duplicated loci, DUPLICATED GAMETOPHYTIC STERILITY 1 (DGS1 on chromosome 4 and DGS2 on chromosome 7, causes pollen sterility in hybrid progeny derived from an interspecific cross between cultivated rice, Oryza sativa, and an Asian annual wild rice, O. nivara. Male gametes carrying the DGS1 allele from O. nivara (DGS1-nivaras and the DGS2 allele from O. sativa (DGS2-T65s were sterile, but female gametes carrying the same genotype were fertile. We isolated the causal gene, which encodes a protein homologous to DNA-dependent RNA polymerase (RNAP III subunit C4 (RPC4. RPC4 facilitates the transcription of 5S rRNAs and tRNAs. The loss-of-function alleles at DGS1-nivaras and DGS2-T65s were caused by weak or nonexpression of RPC4 and an absence of RPC4, respectively. Phylogenetic analysis demonstrated that gene duplication of RPC4 at DGS1 and DGS2 was a recent event that occurred after divergence of the ancestral population of Oryza from other Poaceae or during diversification of AA-genome species.

  5. Fabrication of Activated Rice Husk Charcoal by Slip Casting as a Hybrid Material for Water Filter Aid

    International Nuclear Information System (INIS)

    Tuaprakone, T; Wongphaet, N; Wasanapiarnpong, T

    2011-01-01

    Activated charcoal has been widely used as an odor absorbent in household and water purification industry. Filtration equipment for drinking water generally consists of four parts, which are microporous membrane (porous alumina ceramic or diatomite, or porous polymer), odor absorbent (activated carbon), hard water treatment (ion exchange resin), and UV irradiation. Ceramic filter aid is usually prepared by slip casting of alumina or diatomite. The membrane offers high flux, high porosity and maximum pore size does not exceed 0.3 μm. This study investigated the fabrication of hybrid activated charcoal tube for water filtration and odor absorption by slip casting. The suitable rice husk charcoal and water ratio was 48 to 52 wt% by weight with 1.5wt% (by dry basis) of CMC binder. The green rice husk charcoal bodies were dried and fired between 700-900 deg. C in reduction atmosphere. The resulting prepared slip in high speed porcelain pot for 60 min and sintered at 700 deg. C for 1 h showed the highest specific surface area as 174.95 m 2 /g. The characterizations of microstructure and pore size distribution as a function of particle size were investigated.

  6. Fabrication of Activated Rice Husk Charcoal by Slip Casting as a Hybrid Material for Water Filter Aid

    Science.gov (United States)

    Tuaprakone, T.; Wongphaet, N.; Wasanapiarnpong, T.

    2011-04-01

    Activated charcoal has been widely used as an odor absorbent in household and water purification industry. Filtration equipment for drinking water generally consists of four parts, which are microporous membrane (porous alumina ceramic or diatomite, or porous polymer), odor absorbent (activated carbon), hard water treatment (ion exchange resin), and UV irradiation. Ceramic filter aid is usually prepared by slip casting of alumina or diatomite. The membrane offers high flux, high porosity and maximum pore size does not exceed 0.3 μm. This study investigated the fabrication of hybrid activated charcoal tube for water filtration and odor absorption by slip casting. The suitable rice husk charcoal and water ratio was 48 to 52 wt% by weight with 1.5wt% (by dry basis) of CMC binder. The green rice husk charcoal bodies were dried and fired between 700-900 °C in reduction atmosphere. The resulting prepared slip in high speed porcelain pot for 60 min and sintered at 700 °C for 1 h showed the highest specific surface area as 174.95 m2/g. The characterizations of microstructure and pore size distribution as a function of particle size were investigated.

  7. Fabrication of Activated Rice Husk Charcoal by Slip Casting as a Hybrid Material for Water Filter Aid

    Energy Technology Data Exchange (ETDEWEB)

    Tuaprakone, T; Wongphaet, N; Wasanapiarnpong, T, E-mail: tonggogo@hotmail.com [Research Unit of Advanced Ceramic, Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok (Thailand)

    2011-04-15

    Activated charcoal has been widely used as an odor absorbent in household and water purification industry. Filtration equipment for drinking water generally consists of four parts, which are microporous membrane (porous alumina ceramic or diatomite, or porous polymer), odor absorbent (activated carbon), hard water treatment (ion exchange resin), and UV irradiation. Ceramic filter aid is usually prepared by slip casting of alumina or diatomite. The membrane offers high flux, high porosity and maximum pore size does not exceed 0.3 {mu}m. This study investigated the fabrication of hybrid activated charcoal tube for water filtration and odor absorption by slip casting. The suitable rice husk charcoal and water ratio was 48 to 52 wt% by weight with 1.5wt% (by dry basis) of CMC binder. The green rice husk charcoal bodies were dried and fired between 700-900 deg. C in reduction atmosphere. The resulting prepared slip in high speed porcelain pot for 60 min and sintered at 700 deg. C for 1 h showed the highest specific surface area as 174.95 m{sup 2}/g. The characterizations of microstructure and pore size distribution as a function of particle size were investigated.

  8. Combined Effects of Nutrient and Pesticide Management on Soil Microbial Activity in Hybrid Rice Double Annual Cropping System

    Institute of Scientific and Technical Information of China (English)

    XIEXiao-mei; LIAOMin; LIUWei-ping; SusanneKLOSE

    2004-01-01

    Combined effects on soil microbial activity of nutrient and pesticide management in hybrid rice double annual cropping system were studied. Results of field experiment demonstrated significant changes in soil microbial biomass phospholipid contents,abundance of heterotrophic bacteria and proteolytic bacteria, electron transport system (ETS)/dehydrogenase activity, soil protein contents under different management practices and at various growth stages. Marked depletions in the soil microbial biomass phospholipid contents were found with the advancement of crop growth stages, while the incorporation of fertilizers and/or pesticides also induced slight changes, and the lowest microbial biomass phospholipid content was found with pesticides application alone. A decline in the bacterial abundance of heterotrophic bacteria and proteolytic bacteria was observed during the continuance of crop growth, while the lowest abundance of heterotrophic bacteria and proteolyrJc bacteria was found with pesticides application alone, which coincided with the decline of soil microbial biomass. A consistent increase in the electron transport svstem activit), was measured during the different crop growth stages of rice. The use of fertilizers (NPK) alone or combined with pesticides increased it, while a decline was noticed with pesticides application alone as compared with the control.The soil protein content was found to be relatively stable with fertilizers and/or pesticides application at various growth stages in both crops undertaken, but notable changes were detected at different growrh stages

  9. Combined Effects of Nutrient and Pesticide Management on Soil Microbial Activity in Hybrid Rice Double Annual Cropping System

    Institute of Scientific and Technical Information of China (English)

    XIE Xiao-mei; LIAO Min; LIU Wei-ping; Susanne KLOSE

    2004-01-01

    Combined effects on soil microbial activity of nutrient and pesticide management in hybrid rice double annual cropping system were studied. Results of field experiment demonstrated significant changes in soil microbial biomass phospholipid contents,abundance of heterotrophic bacteria and proteolytic bacteria, electron transport system (ETS)/dehydrogenase activity, soil protein contents under different management practices and at various growth stages. Marked depletions in the soil microbial biomass phospholipid contents were found with the advancement of crop growth stages, while the incorporation of fertilizers and/or pesticides also induced slight changes, and the lowest microbial biomass phospholipid content was found with pesticides application alone. A decline in the bacterial abundance of heterotrophic bacteria and proteolytic bacteria was observed during the continuance of crop growth, while the lowest abundance of heterotrophic bacteria and proteolytic bacteria was found with pesticides application alone, which coincided with the decline of soil microbial biomass. A consistent increase in the electron transport system activity was measured during the different crop growth stages of rice. The use of fertilizers (NPK) alone or combined with pesticides increased it, while a decline was noticed with pesticides application alone as compared with the control.The soil protein content was found to be relatively stable with fertilizers and/or pesticides application at various growth stages in both crops undertaken, but notable changes were detected at different growth stages.

  10. Genetic and biochemical basis of Gall Midge resistance in some cultivars of Indica Rice. Final report for the period 1 October 1980 - 30 November 1986

    International Nuclear Information System (INIS)

    Reddy, G.M.

    1986-01-01

    The stability of high productivity of modern rice varieties is greatly affected by insect pests. Rice gall midge is a serious insect pest of rice that is prevalent in several south eastern asian countries. Gall midge resistance has been mainly attributed to antibiosis. No progress has so far been made in identifying the exact biochemical nature of resistance. In Indica subspecies the understanding of chemical nature of disease would be helpful in the control of the disease and also in breeding programme aimed at developing resistance varieties. Studies were undertaken to establish the biochemical basis of resistance. Biochemical characterization of resistant and susceptible varieties were carried out. The parameters considered were: total sugar and reducing sugar content, total phenol content, amino acid profile, post infectional changes in sugar and phenol, isozyme studies. 2 figs, 6 tabs

  11. Genetic and biochemical basis of Gall Midge resistance in some cultivars of Indica Rice. Final report for the period 1 October 1980 - 30 November 1986

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, G M [Osmania Univ., Hyderabad (India). Dept. of Genetics

    1987-12-31

    The stability of high productivity of modern rice varieties is greatly affected by insect pests. Rice gall midge is a serious insect pest of rice that is prevalent in several south eastern asian countries. Gall midge resistance has been mainly attributed to antibiosis. No progress has so far been made in identifying the exact biochemical nature of resistance. In Indica subspecies the understanding of chemical nature of disease would be helpful in the control of the disease and also in breeding programme aimed at developing resistance varieties. Studies were undertaken to establish the biochemical basis of resistance. Biochemical characterization of resistant and susceptible varieties were carried out. The parameters considered were: total sugar and reducing sugar content, total phenol content, amino acid profile, post infectional changes in sugar and phenol, isozyme studies. 2 figs, 6 tabs.

  12. Physiological and Biochemical Characteristics in Flag Leaves of the C Liangyou Series of Hybrid Rice Combinations at Late Growth Stages

    Directory of Open Access Journals (Sweden)

    Wen-bang TANG

    2010-12-01

    Full Text Available The contents of chlorophyll, soluble sugars, soluble proteins and thiobarbituric acid reaction substance (TBARS, chlorophyll fluorescence parameters, net photosynthetic rate as well as the activities of superoxide dismutase (SOD and peroxidase (POD of flag leaves at the late growth stages were studied by using C Liangyou series of hybrid rice combinitions as material and Shanyou 63 as control. The C Liangyou series of hybrid rice combinations used in the experiment included C Liangyou 396, C Liangyou 87, C Liangyou 755 and C Liangyou 34, which all used C815S as male sterile line. The contents of chlorophyll, soluble sugars and soluble proteins in flag leaves of the C Liangyou series combinations at the late growth stages were higher than those of the control, whereas the TBARS content was lower than that of the control. The activities of SOD and POD were significantly higher than those of the control on the 7th day after heading, and then decreased slowly. FPSII value and qP value of flag leaves decreased at the late growth stages, and these two parameters in flag leaves of the C Liangyou series combinations were higher than those of the control, while the qN value increased at the late growth stages and was lower than that of the control. The net photosynthetic rate of flag leaves at the late growth stage was higher compared with the control. These results suggest that slow senescence and strong photosynthetic capability in flag leaves at the late growth stages are the physiological basis of the C Liangyou series combinations.

  13. QTL mapping of combining ability and heterosis of agronomic traits in rice backcross recombinant inbred lines and hybrid crosses.

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    Zhen Qu

    Full Text Available BACKGROUND: Combining ability effects are very effective genetic parameters in deciding the next phase of breeding programs. Although some breeding strategies on the basis of evaluating combining ability have been utilized extensively in hybrid breeding, little is known about the genetic basis of combining ability. Combining ability is a complex trait that is controlled by polygenes. With the advent and development of molecular markers, it is feasible to evaluate the genetic bases of combining ability and heterosis of elite rice hybrids through QTL analysis. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we first developed a QTL-mapping method for dissecting combining ability and heterosis of agronomic traits. With three testcross populations and a BCRIL population in rice, biometric and QTL analyses were conducted for ten agronomic traits. The significance of general combining ability and special combining ability for most of the traits indicated the importance of both additive and non-additive effects on expression levels. A large number of additive effect QTLs associated with performance per se of BCRIL and general combining ability, and dominant effect QTLs associated with special combining ability and heterosis were identified for the ten traits. CONCLUSIONS/SIGNIFICANCE: The combining ability of agronomic traits could be analyzed by the QTL mapping method. The characteristics revealed by the QTLs for combining ability of agronomic traits were similar with those by multitudinous QTLs for agronomic traits with performance per se of BCRIL. Several QTLs (1-6 in this study were identified for each trait for combining ability. It demonstrated that some of the QTLs were pleiotropic or linked tightly with each other. The identification of QTLs responsible for combining ability and heterosis in the present study provides valuable information for dissecting genetic basis of combining ability.

  14. A novel epistatic interaction at two loci causing hybrid male sterility in an inter-subspecific cross of rice (Oryza sativa L.).

    Science.gov (United States)

    Kubo, Takahiko; Yamagata, Yoshiyuki; Eguchi, Maki; Yoshimura, Atsushi

    2008-12-01

    Postzygotic reproductive isolation (RI) often arises in inter-subspecific crosses as well as inter-specific crosses of rice (Oryza sativa L.). To further understand the genetic architecture of the postzygotic RI, we analyzed genes causing hybrid sterility and hybrid breakdown in a rice inter-subspecific cross. Here we report hybrid male sterility caused by epistatic interaction between two novel genes, S24 and S35, which were identified on rice chromosomes 5 and 1, respectively. Genetic analysis using near-isogenic lines (NILs) carrying IR24 (ssp. indica) segments with Asominori (ssp. japonica) genetic background revealed a complicated aspect of the epistasis. Allelic interaction at the S24 locus in the heterozygous plants caused abortion of male gametes carrying the Asominori allele (S24-as) independent of the S35 genotype. On the other hand, male gametes carrying the Asominori allele at the S35 locus (S35-as) showed abortion only when the IR24 allele at the S24 locus (S24-ir) was concurrently introgressed into the S35 heterozygous plants, indicating that the sterility phenotype due to S35 was dependent on the S24 genotype through negative epistasis between S24-ir and S35-as alleles. Due to the interaction between S24 and S35, self-pollination of the double heterozygous plants produced pollen-sterile progeny carrying the S24-ir/S24-ir S35-as/S35-ir genotype in addition to the S24 heterozygous plants. This result suggests that the S35 gene might function as a modifier of S24. This study presents strong evidence for the importance of epistatic interaction as a part of the genetic architecture of hybrid sterility in rice. In addition, it suggests that diverse systems have been developed as postzygotic RI mechanisms within the rice.

  15. Epigenetic changes and transposon reactivation in Thai rice hybrids. Molecular Breeding

    NARCIS (Netherlands)

    Kantama, L.; Junbuathong, S.; Sakulkoo, J.; Jong, de J.H.S.G.M.; Apisitwanich, S.

    2013-01-01

    Inter- or intraspecific hybridization is the first step in transferring exogenous traits to the germplasm of a recipient crop. One of the complicating factors is the occurrence of epigenetic modifications of the hybrids, which in turn can change their gene expression and phenotype. In this study we

  16. Improving the phenotypic expression of rice genotypes: Rethinking “intensification” for production systems and selection practices for rice breeding

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    Norman Uphoff

    2015-06-01

    Full Text Available Intensification in rice crop production is generally understood as requiring increased use of material inputs: water, inorganic fertilizers, and agrochemicals. However, this is not the only kind of intensification available. More productive crop phenotypes, with traits such as more resistance to biotic and abiotic stresses and shorter crop cycles, are possible through modifications in the management of rice plants, soil, water, and nutrients, reducing rather than increasing material inputs. Greater factor productivity can be achieved through the application of new knowledge and more skill, and (initially more labor, as seen from the System of Rice Intensification (SRI, whose practices are used in various combinations by as many as 10 million farmers on about 4 million hectares in over 50 countries. The highest yields achieved with these management methods have come from hybrids and improved rice varieties, confirming the importance of making genetic improvements. However, unimproved varieties are also responsive to these changes, which induce better growth and functioning of rice root systems and more abundance, diversity, and activity of beneficial soil organisms. Some of these organisms as symbiotic endophytes can affect and enhance the expression of rice plants' genetic potential as well as their phenotypic resilience to multiple stresses, including those of climate change. SRI experience and data suggest that decades of plant breeding have been selecting for the best crop genetic endowments under suboptimal growing conditions, with crowding of plants that impedes their photosynthesis and growth, flooding of rice paddies that causes roots to degenerate and forgoes benefits derived from aerobic soil organisms, and overuse of agrochemicals that adversely affect these organisms as well as soil and human health. This review paper reports evidence from research in India and Indonesia that changes in crop and water management can improve the

  17. Adição de molibdênio ao inoculante turfoso com bactérias diazotróficas usado em duas cultivares de arroz irrigado Addition of molybdenum in peat innoculum with diazotrophic bacteria used in two rice cultivars

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    Salomão Lima Guimarães

    2007-03-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da utilização de bactérias diazotróficas com ou sem molibdênio em duas cultivares de arroz com diferentes potenciais de fixação biológica de nitrogênio. Dois experimentos foram montados: o primeiro foi conduzido em condições gnotobióticas, com utilização das estirpes BR 11417 (ZAE94 - Herbaspirillum seropedicae e BR 11340 (M130 - Burkholderia sp., duas doses de molibdênio, 1,12 e 2,25 g, e duas fontes, molibdato de sódio e molibdato de amônio. As sementes foram peletizadas com inoculante turfoso com bactérias diazotróficas e o molibdênio. Em seguida as cultivares foram plantadas em tubos de ensaio com capacidade para 120 mL com 60 mL da solução de Hoagland sem nitrogênio por 30 dias. Foi avaliada a matéria seca das plantas. O segundo experimento foi conduzido em vasos em casa de vegetação, com as mesmas estirpes e dosagens de molibdênio. Foram avaliados a produção e o N total dos grãos. O delineamento estatístico foi inteiramente casualizado com quatro repetições e quatro plantas por vaso. Foram observados aumentos na produção de grãos nas cultivares IR42 e IAC4440 de 88 e 57%, respectivamente, com a adição ao inoculante turfoso, das estirpes ZAE94 e M130 com molibdênio.The objective of this work was to evaluate the effect of the inoculation of diazotrophic bacteria associated with the molybdenum in two rice cultivars. Two experiments were performed: the first one was lead under gnotobiotics conditions, using Herbaspirillum seropedicae, strain BR 11417 and Burkholderia sp., strain BR 11340, two doses of molybdenum (1.12 and 2.25 g and two different sources of Mo - sodium molybdate and ammonium molybdate. The seeds were pelleted with peat containing diazotrophic bacteria and molybdenum. After inoculations were seeds planted in to test tubes with capacity for 120 mL content 60 mL Hoagland solution without nitrogen. Seedlings were harvested after 30 days and plant

  18. Premature Tapetum Degeneration: a Major Cause of Abortive Pollen Development in Photoperiod Sensitive Genic Male Sterility in Rice

    Institute of Scientific and Technical Information of China (English)

    Yinlian Shi; Sha Zhao; Jialing Yao

    2009-01-01

    Photoperiod-sensitive genic male-sterile (PSGMS) rice (Oryza sativa L.), a natural mutant found in the rice cultivar Nongken 58, is very useful for the development of hybrid rice cultivars. Despite its widespread use in breeding programs, the initial stage of the abortive development of PSGMS rice and the possible cytological mechanisms of pollen abortion have not been determined. In the present study, a systematic cytological comparison of the anther development of PSGMS rice with its normal fertile counterpart is conducted. The results show that pollen abortion in PSGMS rice first occurs before the pollen mother cell (PMC) stage, and continues during the entire process of pollen development until pollen degradation. The abortive process was closely associated with the abnormal behavior of the tapetum. Although tapetum degeneration in PSGMS rice initiates already at the PMC stage, it proceeds slowly and does not complete until the breakdown of the pollen. Such cytological observations were supported by the results of the TUNEL (TdT-mediated dUTP Nick End Labeling) assay, which detects DNA fragmentation resulting from programmed cell death (PCD), indicating that the premature tapetum degeneration is in the process of PCD.

  19. Plant Type and Its Effects on Canopy Structure at Heading Stage in Various Ecological Areas for a Two-line Hybrid Rice Combination, Liangyoupeijiu

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    Chuan-gen LU

    2010-09-01

    Full Text Available A two-line hybrid rice combination, Liangyoupeijiu, was used to estimate several factors of plant type, and environmental models for these factors at the heading stage were established using the data of eight ecological experimental sites in 2006 and 2007. According to climatic data from 1951 to 2005, the differences in those factors and their effects on plant canopy were analyzed for four rice cropping areas in China, including South China, the middle-lower reaches of the Yangtze River, Sichuan Basin, and river valley in Yunnan, China. The thickness of leaf layer (the distance from pulvinus of the third leaf from the top to the tip of flag leaf and distribution of leaf area could be used as candidate indices for the plant type of a rice canopy.

  20. Analysis of nucleotide diversity among alleles of the major bacterial blight resistance gene Xa27 in cultivars of rice (Oryza sativa) and its wild relatives.

    Science.gov (United States)

    Bimolata, Waikhom; Kumar, Anirudh; Sundaram, Raman Meenakshi; Laha, Gouri Shankar; Qureshi, Insaf Ahmed; Reddy, Gajjala Ashok; Ghazi, Irfan Ahmad

    2013-08-01

    Xa27 is one of the important R-genes, effective against bacterial blight disease of rice caused by Xanthomonas oryzae pv. oryzae (Xoo). Using natural population of Oryza, we analyzed the sequence variation in the functionally important domains of Xa27 across the Oryza species. DNA sequences of Xa27 alleles from 27 rice accessions revealed higher nucleotide diversity among the reported R-genes of rice. Sequence polymorphism analysis revealed synonymous and non-synonymous mutations in addition to a number of InDels in non-coding regions of the gene. High sequence variation was observed in the promoter region including the 5'UTR with 'π' value 0.00916 and 'θ w ' = 0.01785. Comparative analysis of the identified Xa27 alleles with that of IRBB27 and IR24 indicated the operation of both positive selection (Ka/Ks > 1) and neutral selection (Ka/Ks ≈ 0). The genetic distances of alleles of the gene from Oryza nivara were nearer to IRBB27 as compared to IR24. We also found the presence of conserved and null UPT (upregulated by transcriptional activator) box in the isolated alleles. Considerable amino acid polymorphism was localized in the trans-membrane domain for which the functional significance is yet to be elucidated. However, the absence of functional UPT box in all the alleles except IRBB27 suggests the maintenance of single resistant allele throughout the natural population.

  1. Transcient expression of â-glucuronidasa on cells suspensión from the hybrid plantain cultivar ‘FHIA-21’ (AAAB

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    Dion Daniels

    2002-04-01

    Full Text Available This work was carried out with the objective of studying parameters that influence transient expression of the enzyme â-glucuronidase in cell suspensions of the plantain hybrid cultivar ‘FHIA-21’ (Musa sp. AAAB. Studies were done with three distances and four pressures. Results of this experiment revealed the importance of the distance and pressure of bombardment, with the most effective being 12 cm and 140 psi respectively with statistical difference to the other treatments. Different plasmid constructs were also studied and it was demonstrated that they didn’t have the same tendencies. The plasmid constructs under the control of the maize polyubiquitin promoter showed better efficiencies than the CaMV 35S promoter. The biological factor is also of great importance. The physiological age of the cell suspensions confirmed its fundamental role in transformation efficiencies with the best results obtained when cell suspensions of five to ten days after subculture were used. Key words: gene gun, genetic transformation, microparticles, Musa sp.

  2. Development and evaluation of a high-throughput, low-cost genotyping platform based on oligonucleotide microarrays in rice

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    Liu Bin

    2008-05-01

    Full Text Available Abstract Background We report the development of a microarray platform for rapid and cost-effective genetic mapping, and its evaluation using rice as a model. In contrast to methods employing whole-genome tiling microarrays for genotyping, our method is based on low-cost spotted microarray production, focusing only on known polymorphic features. Results We have produced a genotyping microarray for rice, comprising 880 single feature polymorphism (SFP elements derived from insertions/deletions identified by aligning genomic sequences of the japonica cultivar Nipponbare and the indica cultivar 93-11. The SFPs were experimentally verified by hybridization with labeled genomic DNA prepared from the two cultivars. Using the genotyping microarrays, we found high levels of polymorphism across diverse rice accessions, and were able to classify all five subpopulations of rice with high bootstrap support. The microarrays were used for mapping of a gene conferring resistance to Magnaporthe grisea, the causative organism of rice blast disease, by quantitative genotyping of samples from a recombinant inbred line population pooled by phenotype. Conclusion We anticipate this microarray-based genotyping platform, based on its low cost-per-sample, to be particularly useful in applications requiring whole-genome molecular marker coverage across large numbers of individuals.

  3. Does African catfish ( Clarias gariepinus ) affect rice in integrated ...

    African Journals Online (AJOL)

    An experiment was conducted for 98 days in the Lake Victoria Basin to investigate the interactions of fish and rice growth performance in rice paddies. The experiment was laid out in a split-plot design, with rice cultivar as the main plot and method of rice-fish culture as the sub-plot. Treatments consisted of two levels of ...

  4. Effect of temperature and time immersion of stage soaking on color grains of upland rice parboiled cultivars/ Efeito da temperatura e do tempo de imersão da etapa de encharcamento sobre a cor dos grãos de arroz parboilizado de cultivares de terras altas

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    Priscila Zaczuk Bassinelo

    Full Text Available The parboiling is the hydrothermal treatment of paddy before processing. The objective of this study was to evaluate the influence of the temperature and immersion time step of soaking (independent variables on the color of the grain parboiled (dependent variable cultivars of upland rice (BRS Primavera and BRS Sertaneja. A central composite rotational design (DCCR was used, which includes a 22 full factorial, three replicates at the center point and four axial points, making eleven treatments. It was considered for the selection of hydrothermal conditions to be studied, the criterion of water absorption in the age group from 28% - 32%. In extreme conditions of soaking (high temperature and immersion time was observed in general that the grains of parboiled rice had higher color difference for the samples of grains of white rice. Therefore, the use of temperatures below 65 °C during the soaking tend to have grains with milder browning. After parboiling under different conditions of temperature and time of soaking, the change of color (?E* was greater in cv. BRS Sertaneja. It is possible to produce grains with different shades, depending on the conditions used. The choice will depend on the application that is intended or products in wich the rice will be employed.A parboilização consiste no tratamento hidrotérmico do arroz em casca antes do beneficiamento. O objetivo deste estudo foi avaliar a influência das variáveis temperatura e tempo de imersão da etapa de encharcamento sobre a cor dos grãos parboilizados de cultivares de arroz de terras altas (BRS Primavera e BRS Sertaneja. Utilizou-se um delineamento composto central rotacional (DCCR, que inclui um fatorial completo 22, mais três repetições no ponto central e quatro pontos axiais, totalizando onze tratamentos. Considerou-se para seleção das condições hidrotérmicas, o critério de absorção de água na faixa de 28% – 32%. Nas condições extremas do encharcamento (elevada

  5. Physiological changes and sHSPs genes relative transcription in relation to the acquisition of seed germination during maturation of hybrid rice seed.

    Science.gov (United States)

    Zhu, Li-Wei; Cao, Dong-Dong; Hu, Qi-Juan; Guan, Ya-Jing; Hu, Wei-Min; Nawaz, Aamir; Hu, Jin

    2016-03-30

    During the production of early hybrid rice seed, the seeds dehydrated slowly and retained high moisture levels when rainy weather lasted for a couple of days, and the rice seeds easily occurred pre-harvest sprouting (PHS) along with high temperature. Therefore it is necessary to harvest the seeds before the PHS occurred. The seeds of hybrid rice (Oryza sativa L. subsp. indica) cv. Qianyou No1 that harvests from 19 to 28 days after pollination (DAP) all had high seed vigour. The seed moisture content at 10 DAP was 36.1%, and declined to 28.6% at 19 DAP; the contents of soluble sugar and total starch increased significantly with the development of seeds. The soluble protein content, the level of abscisic acid (ABA) and gibberellin (GA3 ), and ascorbate peroxidase (APX) activity continued to decrease from 10 DAP to 19 DAP. The seeds at 19 DAP had the highest peroxidase (POD) activity and lowest catalase (CAT) activity while the superoxide dismutase (SOD) activity had no significant difference among the different developing periods. The relative expressions of genes 64S Hsp18.0 and Os03g0267200 transcripts increased significantly from 10 to 19 DAP, and then decreased. However, no significant change was recorded in soluble protein, sugar and GA3 after 16 DAP, and they all significantly correlated with seed viability and vigour during the process of seed maturity. The seeds of hybrid rice Qianyou No1 had a higher viability and vigour when harvested from 19 DAP to 28 DAP, the transcription levels of 64S Hsp18.0 and Os03g0267200 increased significantly from 10 DAP to 19 DAP and the highest value was recorded at 19 DAP. The seeds could be harvested as early as 19 DAP without negative influence on seed vigour and viability. © 2015 Society of Chemical Industry.

  6. Broken rice kernels and the kinetics of rice hydration and texture during cooking.

    Science.gov (United States)

    Saleh, Mohammed; Meullenet, Jean-Francois

    2013-05-01

    During rice milling and processing, broken kernels are inevitably present, although to date it has been unclear as to how the presence of broken kernels affects rice hydration and cooked rice texture. Therefore, this work intended to study the effect of broken kernels in a rice sample on rice hydration and texture during cooking. Two medium-grain and two long-grain rice cultivars were harvested, dried and milled, and the broken kernels were separated from unbroken kernels. Broken rice kernels were subsequently combined with unbroken rice kernels forming treatments of 0, 40, 150, 350 or 1000 g kg(-1) broken kernels ratio. Rice samples were then cooked and the moisture content of the cooked rice, the moisture uptake rate, and rice hardness and stickiness were measured. As the amount of broken rice kernels increased, rice sample texture became increasingly softer (P hardness was negatively correlated to the percentage of broken kernels in rice samples. Differences in the proportions of broken rice in a milled rice sample play a major role in determining the texture properties of cooked rice. Variations in the moisture migration kinetics between broken and unbroken kernels caused faster hydration of the cores of broken rice kernels, with greater starch leach-out during cooking affecting the texture of the cooked rice. The texture of cooked rice can be controlled, to some extent, by varying the proportion of broken kernels in milled rice. © 2012 Society of Chemical Industry.

  7. Do the rich always become richer? Characterizing the leaf physiological response of the high-yielding rice cultivar Takanari to free-air CO2 enrichment.

    Science.gov (United States)

    Chen, Charles P; Sakai, Hidemitsu; Tokida, Takeshi; Usui, Yasuhiro; Nakamura, Hirofumi; Hasegawa, Toshihiro

    2014-02-01

    The development of crops which are well suited to growth under future environmental conditions such as higher atmospheric CO2 concentrations ([CO2]) is essential to meeting the challenge of ensuring food security in the face of the growing human population and changing climate. A high-yielding indica rice variety (Oryza sativa L. cv. Takanari) has been recently identified as a potential candidate for such breeding, due to its high productivity in present [CO2]. To test if it could further increase its productivity under elevated [CO2] (eCO2), Takanari was grown in the paddy field under season-long free-air CO2 enrichment (FACE, approximately 200 µmol mol(-1) above ambient [CO2]) and its leaf physiology was compared with the representative japonica variety 'Koshihikari'. Takanari showed consistently higher midday photosynthesis and stomatal conductance than Koshihikari under both ambient and FACE growth conditions over 2 years. Maximum ribulose-1,5-bisphosphate carboxylation and electron transport rates were higher for Takanari at the mid-grain filling stage in both years. Mesophyll conductance was higher in Takanari than in Koshihikari at the late grain-filling stage. In contrast to Koshihikari, Takanari grown under FACE conditions showed no decrease in total leaf nitrogen on an area basis relative to ambient-grown plants. Chl content was higher in Takanari than in Koshihikari at the same leaf nitrogen level. These results indicate that Takanari maintains its superiority over Koshihikari in regards to its leaf-level productivity when grown in elevated [CO2] and it may be a valuable resource for rice breeding programs which seek to increase crop productivity under current and future [CO2].

  8. Short communication. A spontaneous mutant of L-202 rice

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Yzaguire, A.; Padrones, T.

    2009-07-01

    A new spontaneous phenotype of the rice cultivar L-202 was found. Mendelian analysis indicates that it is a monogenic, recessive mutant. Its distinguishing features are: dark blue-green colour, short and narrow leaves, high tillering and relatively short height. The objectives of this study were: to characterize it, to determine if it is heritable and if so, its genetic basis. Its distinguishing features are: dark blue-green colour, short and narrow leaves, high tillering and relatively short height. Selfing the new phenotype resulted in a uniform progeny, with the traits of the parent plant (wild type). Crossing the new phenotype with the normal L-202 cultivar resulted in a uniform F1 hybrid generation, with the wild type. The F2 generation showed a mendelian segregation which did not depart significantly from three normal plants : one new phenotype. It is concluded that it is a monogenic, recessive mutant. (Author) 3 refs.

  9. Patterns of cytosine methylation in an elite rice hybrid and its parental lines, detected by a methylation-sensitive amplification polymorphism technique.

    Science.gov (United States)

    Xiong, L Z; Xu, C G; Saghai Maroof, M A; Zhang, Q

    1999-04-01

    DNA methylation is known to play an important role in the regulation of gene expression in eukaryotes. In this study, we assessed the extent and pattern of cytosine methylation in the rice genome, using the technique of methylation-sensitive amplified polymorphism (MSAP), which is a modification of the amplified fragment length polymorphism (AFLP) method that makes use of the differential sensitivity of a pair of isoschizomers to cytosine methylation. The tissues assayed included seedlings and flag leaves of an elite rice hybrid, Shanyou 63, and the parental lines Zhenshan 97 and Minghui 63. In all, 1076 fragments, each representing a recognition site cleaved by either or both of the isoschizomers, were amplified using 16 pairs of selective primers. A total of 195 sites were found to be methylated at cytosines in one or both parents, and the two parents showed approximately the same overall degree of methylation (16.3%), as revealed by the incidence of differential digestion by the isoschizomers. Four classes of patterns were identified in a comparative assay of cytosine methylation in the parents and hybrid; increased methylation was detected in the hybrid compared to the parents at some of the recognition sites, while decreased methylation in the hybrid was detected at other sites. A small proportion of the sites was found to be differentially methylated in seedlings and flag leaves; DNA from young seedlings was methylated to a greater extent than that from flag leaves. Almost all of the methylation patterns detected by MSAP could be confirmed by Southern analysis using the isolated amplified fragments as probes. The results clearly demonstrate that the MSAP technique is highly efficient for large-scale detection of cytosine methylation in the rice genome. We believe that the technique can be adapted for use in other plant species.

  10. RESPOSTA DE DUAS CULTIVARES DE ARROZ DE TERRAS ALTAS EM CONVIVÊNCIA COM Brachiaria brizantha

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    Abdias Alves De Oliveira

    2009-01-01

    Full Text Available The objective of this work was to evaluate to the sowing time of the Brachiaria brizantha forage intercrop with two upland rice cultivars on the agronomics characteristics of both species. It was used randomized blocks in experimental design arranged in factorial scheme 2x2+4, with four replicates. The first factor was constituted by the upland rice cultivars (BRS Primavera e BRSMG Curinga and the second factor by two sowing times of B. brizantha forage (simultaneous sowing between rice and forage and sowing of the forage in the flowering of the rice. The additional treatments consisted of the sole crops upland rice cultivars and B. brizantha forage for each sowing time. In rice was evaluated the height of the plants, bedding, difficulty of the harvest, the number of panicles per area, grain per panicles, percentage of full and empty grains, 100-grain mass and grain yield. In the B. brizantha forage was evaluated the height of the tillers, the total dry mass and the rate of cultural growth. It was observed that the B. brizantha forage interfered in the productivity components of both upland rice cultivars and difficult significantly the harvest of the rice. The upland rice cultivars showed small competitive capacity with the B. brizantha forage when the establishment of the forage occurred simultaneously to the rice. However, to the measure that the sowing was occurred with the established rice already, the B. brizantha forage had his growth suppressed.

  11. Transgenic rice expressing a codon-modified synthetic CP4-EPSPS confers tolerance to broad-spectrum herbicide, glyphosate.

    Science.gov (United States)

    Chhapekar, Sushil; Raghavendrarao, Sanagala; Pavan, Gadamchetty; Ramakrishna, Chopperla; Singh, Vivek Kumar; Phanindra, Mullapudi Lakshmi Venkata; Dhandapani, Gurusamy; Sreevathsa, Rohini; Ananda Kumar, Polumetla

    2015-05-01

    Highly tolerant herbicide-resistant transgenic rice was developed by expressing codon-modified synthetic CP4--EPSPS. The transformants could tolerate up to 1% commercial glyphosate and has the potential to be used for DSR (direct-seeded rice). Weed infestation is one of the major biotic stress factors that is responsible for yield loss in direct-seeded rice (DSR). Herbicide-resistant rice has potential to improve the efficiency of weed management under DSR. Hence, the popular indica rice cultivar IR64, was genetically modified using Agrobacterium-mediated transformation with a codon-optimized CP4-EPSPS (5-enolpyruvylshikimate-3-phosphate synthase) gene, with N-terminal chloroplast targeting peptide from Petunia hybrida. Integration of the transgenes in the selected rice plants was confirmed by Southern hybridization and expression by Northern and herbicide tolerance assays. Transgenic plants showed EPSPS enzyme activity even at high concentrations of glyphosate, compared to untransformed control plants. T0, T1 and T2 lines were tested by herbicide bioassay and it was confirmed that the transgenic rice could tolerate up to 1% of commercial Roundup, which is five times more in dose used to kill weeds under field condition. All together, the transgenic rice plants developed in the present study could be used efficiently to overcome weed menace.

  12. Molecular phylogenomic study and the role of exogenous spermidine in the metabolic adjustment of endogenous polyamine in two rice cultivars under salt stress.

    Science.gov (United States)

    Saha, Jayita; Giri, Kalyan

    2017-04-20

    Compelling evidences anticipated the well acclamation of involvement of exogenous and endogenous polyamines (PAs) in conferring salt tolerance in plants. Intracellular PA's anabolism and catabolism should have contributed to maintain endogenous PAs homeostasis to induce stress signal networks. In this report, the evolutionary study has been conducted to reveal the phylogenetic relationship of genes encoding enzymes of the anabolic and catabolic pathway of PAs among the five plant lineages including green algae, moss, lycophyte, dicot and monocot along with their respective exon-intron structural patterns. Our results indicated that natural selection pressure had considerable influence on the ancestral PA metabolic pathway coding genes of land plants. PA metabolic genes have undergone gradual evolution by duplication and diversification process leading to subsequent structural modification through exon-intron gain and loss events to acquire specific function under environmental stress conditions. We have illuminated on the potential regulation of both the pathways by investigating the real-time expression analyses of PA metabolic pathway related enzyme coding genes at the transcriptional level in root and shoot tissues of two indica rice varieties, namely IR 36 (salt sensitive) and Nonabokra (salt-tolerant) in response to salinity in presence or absence of exogenous spermidine (Spd) treatment. Additionally, we have performed tissue specific quantification of the intracellular PAs and tried to draw probable connection between the PA metabolic pathway activation and endogenous PAs accumulation. Our results successfully enlighten the fact that how exogenous Spd in presence or absence of salt stress adjust the intracellular PA pathways to equilibrate the cellular PAs that would have been attributed to plant salt tolerance. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Clustering of 18 Local Black Rice Base on Total Anthocyanin

    Directory of Open Access Journals (Sweden)

    Kristamtini Kristamtini

    2017-10-01

    Full Text Available Black rice has a high anthocyanin content in the pericarp layer, which provides a dark purple color. Anthocyanin serve as an antioxidant that control cholesterol level in the blood, prevent anemia, potentially improve the body's resistance to disease, improve damage to liver cells (hepatitis and chirrosis, prevent impaired kidney function, prevent cancer/tumors, slows down antiaging, and prevent atherosclerosis and cardiovascular disease. Exploration results at AIAT Yogyakarta, Indonesia from 2011 to 2014 obtained 18 cultivar of local black rice Indonesia. The names of the rice are related to the color (black, red or purple formed by anthocyanin deposits in the pericarp layer, seed coat or aleuron. The objective of the study was to classify several types of local black rice from explorations based on the total anthocyanin content. The study was conducted by clustering analyzing the total anthocyanin content of 18 local black rice cultivars in Indonesia. Cluster analysis of total anthocyanin content were done using SAS ver. 9.2. Clustering dendogram shows that there were 4 groups of black rice cultivars based on the total anthocyanin content. Group I consists of Melik black rice, Patalan black rice, Yunianto black rice, Muharjo black rice, Ngatijo black rice, short life of Tugiyo black rice, Andel hitam 1, Jlitheng, and Sragen black rice. Group II consists of Pari ireng, Magelang black hairy rice, Banjarnegara-Wonosobo black rice, and Banjarnegara black rice. Group III consists of NTT black rice, Magelang non hairy black rice, Sembada hitam, and longevity Tugiyo black rice. Group IV consist only one type of black rice namely Cempo ireng. The grouping result indicate the existence of duplicate names among the black rice namely Patalan with Yunianto black rice, and short life Tugiyo with Andel hitam 1 black rice.

  14. An Aerial Robot for Rice Farm Quality Inspection With Type-2 Fuzzy Neural Networks Tuned by Particle Swarm Optimization-Sliding Mode Control Hybrid Algorithm

    DEFF Research Database (Denmark)

    Camci, Efe; Kripalan, Devesh Raju; Ma, Linlu

    2017-01-01

    , an autonomous quality inspection over rice farms is proposed by employing quadcopters. Real-time control of these vehicles, however, is still challenging as they exhibit highly nonlinear behavior especially for agile maneuvers. What is more, these vehicles have to operate under uncertain working conditions...... particle swarm optimization-sliding mode control (PSO-SMC) theory-based hybrid algorithm is proposed for the training of T2-FNNs. In particular, continuous version of PSO is adopted for the identification of the antecedent part of T2-FNNs while SMCbased update rules are utilized for online learning...

  15. Significance of rice sheath photosynthesis: Yield determination by ...

    African Journals Online (AJOL)

    Using high-yielding hybrid rice Liangyopeijiu (LYP9), its male parent 9311 and hybrid rice Shanyou 63 (SY63) as the experimental materials, the photosynthesis of rice sheath was studied by 14C radio-autography. The results showed that rice sheath could trap sunlight and produce photosynthates, and these ...

  16. Response of Transplanted Aman Rice Varieties to Herbicides in Strip-Tilled Non-Puddled Soil

    Directory of Open Access Journals (Sweden)

    Taslima Zahan1

    2017-12-01

    Full Text Available BACKGROUND: Sensitivity of crop cultivars may vary to commonly used herbicides resulting in potential yield loss and reduce farm profit. Transplanting of rice seedlings in strip-tilled non-puddled field is a new practice for which herbicide tolerant varieties need to select. Therefore, a study was executed at the Agronomy Field Laboratory of Bangladesh Agricultural University, Mymensingh during 2013 to evaluate the response of some popular transplanted aman rice varieties to different herbicides at their recommended rate and to select most tolerant aman rice variety or varieties for strip-tilled non-puddled transplanting. METHODOLOGY: Twelve aman rice varieties (BR11, BRRI dhan33, BRRI dhan39, BRRI dhan44, BRRI dhan46, BRRI dhan49, BRRI dhan51, BRRI dhan52, BRRI dhan56, BRRI dhan57, BRRI hybrid dhan-4 and BINA dhan7 were examined in the study against six herbicides (2 pre-emergence: pyrazosulfuron-ethyl and butachlor; 1 early post-emergence: orthosulfamuron and 3 late post-emergence: acetochlor + bensulfuron methyl, butachlor + propanil and 2,4-D amine along with one untreated manually weed-free control. KEY FINDINGS: The study revealed that aman rice varieties responded differentially to different herbicides. All rice varieties performed better in pyrazosulfuron-ethyl treated plots relative to the other herbicide treated plots and even than the control plots. Pyrazosulfuron-ethyl increased grain yield of all aman rice varieties by 0.6-32.6% over control and butachlor + propanil provided increased grain yield in all rice varieties by 2.0-25.5% except BRRI hybrid dhan-4. The study also disclosed that BRRI dhan57 and BRRI hybrid dhan-4 gone through the yield loss by application of 2,4-D amine and BRRI dhan56 by application of butachlor and orthosulfamuron. Moreover, acetochlor + bensulfuron methyl produced shorter plants and caused yield loss by 7.8-27.1% in all aman rice varieties compared to the control and BRRI dhan39 was the most susceptible

  17. Survey of rice blast race identity for blast resistance gene identification in the USA and Puerto Rico

    Science.gov (United States)

    Rice blast disease is a significant threat to stable rice production in the USA and worldwide. The major resistance gene (Pi-ta) located within a cluster of resistance genes on rice chromosome 12 has been demonstrated to confer resistance to the rice blast disease. Katy, a rice cultivar released in ...

  18. Analysis of QTLs for yield-related traits in Yuanjiang common wild rice (Oryza rufipogon Griff.).

    Science.gov (United States)

    Fu, Qiang; Zhang, Peijiang; Tan, Lubin; Zhu, Zuofeng; Ma, Dan; Fu, Yongcai; Zhan, Xinchun; Cai, Hongwei; Sun, Chuanqing

    2010-02-01

    Using an accession of common wild rice (Oryza rufipogon Griff.) collected from Yuanjiang County, Yunnan Province, China, as the donor and an elite cultivar 93-11, widely used in two-line indica hybrid rice production in China, as the recurrent parent, an advanced backcross populations were developed. Through genotyping of 187 SSR markers and investigation of six yield-related traits of two generations (BC(4)F(2) and BC(4)F(4)), a total of 26 QTLs were detected by employing single point analysis and interval mapping in both generations. Of the 26 QTLs, the alleles of 10 (38.5%) QTLs originating from O. rufipogon had shown a beneficial effect for yield-related traits in the 93-11 genetic background. In addition, five QTLs controlling yield and its components were newly identified, indicating that there are potentially novel alleles in Yuanjiang common wild rice. Three regions underling significant QTLs for several yield-related traits were detected on chromosome 1, 7 and 12. The QTL clusters were founded and corresponding agronomic traits of those QTLs showed highly significant correlation, suggesting the pleiotropism or tight linkage. Fine-mapping and cloning of these yield-related QTLs from wild rice would be helpful to elucidating molecular mechanism of rice domestication and rice breeding in the future. Copyright 2010 Institute of Genetics and Developmental Biology and the Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

  19. Developing selection protocols for weed competitiveness in aerobic rice

    NARCIS (Netherlands)

    Zhao, D.L.; Atlin, G.N.; Bastiaans, L.; Spiertz, J.H.J.

    2006-01-01

    Aerobic rice production systems, wherein rice is dry-sown in non-puddled soil and grown as an upland crop, offer large water savings but are subject to severe weed infestation. Weed-competitive cultivars will be critical to the adoption of aerobic rice production by farmers. Breeding

  20. Association mapping of stigma and spikelet characteristics in rice (Oryza sativa L.)

    Science.gov (United States)

    Hybrid rice exhibits a yield advantage of 15 to 20 percent (or more than one ton of paddy rice per hectare) over the best traditional varieties. Because rice plants are self-pollinating, commercial production of hybrid seed plays a key role in successful implementation of hybrid rice. Stigma exserti...

  1. Sorghum and rice: Mali

    International Nuclear Information System (INIS)

    2003-01-01

    Agriculture is the mainstay of the Malian economy and yet cereal imports absorb 6.5% of GDP. Food self-sufficiency is therefore a national priority. The Joint FAO/IAEA Division is supporting a programme to improve local varieties of sorghum and rice by using nuclear techniques to develop new cultivars that will produce higher yields under Mali's semi-arid climatic conditions. (IAEA)

  2. Growth and Productivity of Response of Hybrid Rice to Application of Animal Manures, Plant Residues and Phosphorus

    Directory of Open Access Journals (Sweden)

    Dr. Amanullah

    2016-10-01

    Full Text Available The objective of this research was to evaluate the impact of organic sources (animal manures vs. plant residues at the rate of 10 t ha-1 each on the productivity profitability of small land rice (Oryza sativa L. grower under different levels of phosphorus (0, 30, 60 and 90 kg P ha-1 fertilization. Two separate field experiments were conducted. In experiment (1, impact of three animal manures sources (cattle, sheep & poultry manures and P levels was studied along with one control plot (no animal manure and P applied as check was investigated. In experiment (2, three plant residues sources (peach leaves, garlic residues & wheat straw and P levels was studied along with one control plot (no plant residues and P applied as check. Both the experiments were carried out on small land farmer field at District Swabi, Khyber Pakhtunkhwa Province (Northwest Pakistan during summer 2015. The results revealed that in both experiments the control plot had significantly (p≤0.05 less productivity than the average of all treated plots with organic sources and P level. The increase in P levels in both experiments (animal manure vs. plant residues had resulted in higher rice productivity (90 = 60 > 30 > 0 kg P ha-1. In the experiment under animal manures, application of poultry manure increased rice productivity as compared with sheep and cattle manures (poultry > sheep > cattle manures. In the experiment under plant residues, application of peach leaves or garlic resides had higher rice productivity over wheat straw (peach leaves = garlic residues > wheat straw. On the average, the rice grown under animal manures produced about 20% higher grain yield than the rice grown under crop residues. We concluded from this study that application of 90 kg P ha-1 along with combined application of animal manures especially poultry manure could increase rice productivity. We conclude from this study that application of 90 kg P ha-1 along with combined application of animal

  3. Uso da água por plantas híbridas ou convencionais de arroz irrigado Water use by hybrid and conventional rice plants

    Directory of Open Access Journals (Sweden)

    G. Concenço

    2009-01-01

    Full Text Available Objetivou-se com este trabalho avaliar as características associadas à eficiência do uso da água em plantas de arroz irrigado, híbridas ou convencionais. O experimento foi instalado em casa de vegetação, em delineamento experimental de blocos casualizados em esquema fatorial 2 x 6, com quatro repetições. Os tratamentos constaram de uma planta de arroz da variedade BRS Pelota (convencional ou Inov (híbrida no centro da unidade experimental, que competia com 0, 1, 2, 3, 4 ou 5 plantas da variedade BRS Pelota na periferia da unidade experimental, de acordo com o tratamento. Aos 50 DAE, foram realizadas as avaliações de massa seca da parte aérea, condutância estomática de vapores de água, temperatura da folha e taxa de transpiração, sendo calculada ainda a eficiência do uso da água pela relação entre quantidade de CO2 fixado pela fotossíntese e quantidade de água transpirada. Plantas da variedade híbrida foram superiores ou não diferiram das convencionais quanto à eficiência do uso da água.The objective of this work was to evaluate the characteristics associated to water use efficiency in hybrid or conventional rice plants. The trial was installed under greenhouse conditions, in a completely randomized block design and factorial scheme 2 x 6, with four replications. The treatments consisted of one hybrid (Inov or conventional (BRS Pelota rice plant at the center of the plot surrounded by 0, 1, 2, 3, 4, or 5 conventional (BRS Pelota plants. Fifty days after emergence, shoot dry mass, stomatal conductance of water vapor, leaf temperature and transpiration rates were evaluated, as well as water use efficiency through the relation between the photosynthesis and transpiration rates. Hybrid rice plants were superior to, or did not differ from, the conventional plants in relation to water use efficiency.

  4. Influence of Genetic Drift of Restoring Gene (Rf on Seed Purity of Yuetai A, a Honglian-Type Cytoplasmic Male Sterile Line in Hybrid Rice

    Directory of Open Access Journals (Sweden)

    Ji-feng Wang

    2008-06-01

    Full Text Available The seed samples of Yuetai A, a Honglian (HL type cytoplasmic male sterile (CMS line in hybrid rice were investigated to assess the seed purity and to analyze the cause of off-type plants by imitating the biological contaminant to Yuetai A in Nanjing, Jiangsu Province and Lingshui, Hainan Province during 2004–2006. The seed impurity of Yuetai A mainly resulted from the genetic drift of restoring fertility gene (Rf after biological contamination but not from its sterility unstability. All of the ten maintainer lines, five restorer lines and three thermo-sensitive genic male sterile lines used in the study could pollinate Yuetai A and Yuetai B to produce F1 plants, directly or indirectly resulting in Rf-gene drifting into Yuetai A and generating ‘iso-cytoplasm restoring-generations’. Furthermore, high outcrossing rate and similar heading date of Yuetai A with many varieties used in rice production might easily result in the biological contamination. After removing all plants with Rf-gene mixed in Yuetai A and preventing Rf-gene drifting into Yuetai A, the seed purity of Yuetai A and Yuetai B had been raised to 100%.

  5. Processing properties of grains from some maize cultivars ...

    African Journals Online (AJOL)

    For the dry milling, whole or pealed grains were simply processed in a hammer mill and the flour fractions separated as with wet milling. Results indicated some variation in the proximate composition with nine cultivars exhibiting protein contents above 8%. High protein cultivars were in order hybrids 88094X87036, ...

  6. The Challenges and Solutions for Cadmium-contaminated Rice in China: A Critical Review.

    Science.gov (United States)

    Hu, Yuanan; Cheng, Hefa; Tao, Shu

    2016-01-01

    The wide occurrence of Cd-contaminated rice in southern China poses significant public health risk and deserves immediate action, which arises primarily from extensive metal (including Cd) contamination of paddies with the fast expansion of nonferrous metal mining and smelting activities. Accumulation of Cd in rice grains can be reduced by removing Cd from the contaminated paddy soils, reducing its bioavailability, and controlling its uptake by rice plants. Although a range of measures can be taken to rehabilitate Cd-contaminated lands, including soil replacement and turnover, chemical washing, and phytoremediation, they are either too expensive and/or too slow. Various amendment materials, including lime, animal manures, and biochar, can be used to immobilize Cd in soils, but such fixation approach can only temporarily reduce Cd availability to rice uptake. Cultivation of alternative crops with low Cd accumulation in edible plant parts is impractical on large scales due to extensive contamination and food security concerns in southern China. Transgenic techniques can help develop rice cultivars with low Cd accumulation in grains, but little public acceptance is expected for such products. As an alternative, selection and development of low-Cd rice varieties and hybrids through plant biotechnology and breeding, particularly, by integration of marker-assisted selection (MAS) with traditional breeding, could be a practical and acceptable option that would allow continued rice production in soils with high bioavailability of Cd. Plant biotechnology and breeding can also help develop Cd-hyperaccumulating rice varieties, which can greatly facilitate phytoremediation of contaminated paddies. To eliminate the long-term risk of Cd entering the food chain, soils contaminated by Cd should be cleaned up when cost-effective remediation measures are available. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Why are There Indica Type and Japonica Type in Rice? — History of the Studies and a View for Origin of Two Types

    Directory of Open Access Journals (Sweden)

    Hiroshi IKEHASHI

    2009-03-01

    Full Text Available On the bases of archaeological discoveries, the earliest domestication of rice has been confirmed in the middle and lower Changjiang River basin, while in the region wild rice populations are found in shallow swamps under a climate with freezing winter cold. These findings lead us re-examine the past ideas about domestication and differentiation of rice. Historically, in 1930s two sub-species, indica and japonica, were proposed on the basis of sterility in F1 hybrids between them. Soon after that, the two types were classified by the associations of a number of genetically independent traits. The characteristic associations of traits have been explained by the hybrid sterility or reproductive barriers which were assumed to comprise a set of duplicate recessive lethal genes and to be an inner genetic mechanism to lead to the varietal differentiations. In 1980s, the hybrid sterility between Indica and Japonica types was analyzed, and Indica, Japonica, and wide-compatibility type which gives fertile hybrids when cross to Indica and Japonica types, are proved to contain an allele, S5i, S5j and S5n, respectively at a locus on chromosome 6. And those gametes having S5j allele are found to be partially aborted in the hybrid genotypes of S5i/S5j while no gamete abortion occurs in S5i/S5n and S5j/S5n genotypes. Since then, the gene S5n has been used in hybrid rice breeding to obtain fertile and vigorous hybrids between subspecies, and the long-disputed problem of hybrid sterility has been solved. Also in such studies the characteristic association of traits found in each of varietal groups is better explained by founder effects. On the other hand, a large number of native cultivars of rice were surveyed with enzyme polymorphism in 1980s and later with molecular markers. As a result, profound genetic diversity is found in cultivated rice as well as in wild rice. These findings seem to lead us to the idea of multiple independent domestications of rice

  8. Pathogenicity of Heterodera daverti, H. zeae, and Meloidogyne incognita on rice

    Science.gov (United States)

    The reactions of five rice cultivars to the cyst nematodes Heterodera daverti and H. zeae and the root-knot nematode Meloidogyne incognita were determined in the greenhouse. The results showed that both H. daverti and H. zeae infected and reproduced successfully on some of the tested rice cultivars....

  9. Expression of hybrid fusion protein (Cry1Ac::ASAL) in transgenic rice plants imparts resistance against multiple insect pests.

    Science.gov (United States)

    Boddupally, Dayakar; Tamirisa, Srinath; Gundra, Sivakrishna Rao; Vudem, Dashavantha Reddy; Khareedu, Venkateswara Rao

    2018-05-31

    To evolve rice varieties resistant to different groups of insect pests a fusion gene, comprising DI and DII domains of Bt Cry1Ac and carbohydrate binding domain of garlic lectin (ASAL), was constructed. Transgenic rice lines were generated and evaluated to assess the efficacy of Cry1Ac::ASAL fusion protein against three major pests, viz., yellow stem borer (YSB), leaf folder (LF) and brown planthopper (BPH). Molecular analyses of transgenic plants revealed stable integration and expression of the fusion gene. In planta insect bioassays on transgenics disclosed enhanced levels of resistance compared to the control plants. High insect mortality of YSB, LF and BPH was observed on transgenics compared to that of control plants. Furthermore, honeydew assays revealed significant decreases in the feeding ability of BPH on transgenic plants as compared to the controls. Ligand blot analysis, using BPH insects fed on cry1Ac::asal transgenic rice plants, revealed a modified receptor protein-binding pattern owing to its ability to bind to additional receptors in insects. The overall results authenticate that Cry1Ac::ASAL protein is endowed with remarkable entomotoxic effects against major lepidopteran and hemipteran insects. As such, the fusion gene appears promising and can be introduced into various other crops to control multiple insect pests.

  10. Evaluation of Mechanical Properties and Morphological Studies of Rice Husk (Treated/Untreated)-CaCO3 Reinforced Epoxy Hybrid Composites

    Science.gov (United States)

    Verma, Deepak; Joshi, Garvit; Gupta, Ayush

    2016-10-01

    Natural fiber reinforced composites are a very popular area of research because of the easy availability and biodegradability of these fibers. The manufacturing of natural fiber composite is done by reinforcing fibers in the particulate form, fiber form or in woven mat form. Natural fiber composites also utilize industrial wastes as a secondary reinforcements like fly ash, sludge etc. By keeping all these point of views in the present investigation the effect of rice husk flour (chemically treated/untreated) and micro sized calcium carbonate with epoxy resin have been evaluated. The diameter of rice husk flour was maintained at 600 µm through mechanical sieving machine. The husk flour was chemically treated with NaOH (5 % w/v). Mechanical properties like hardness, flexural impact and compression strength were evaluated and found to be superior in modified or chemically treated flour as compared to unmodified or untreated flour reinforced composites. Scanning electron microscopy (SEM) study was also undertaken for the developed composites. SEM study shows the distribution of the rice husk flour and calcium carbonate over the matrix.

  11. Characteristics of bread prepared from wheat flours blended with various kinds of newly developed rice flours.

    Science.gov (United States)

    Nakamura, S; Suzuki, K; Ohtsubo, K

    2009-04-01

    Characteristics of the bread prepared from wheat flour blended with the flour of various kinds of newly developed rice cultivars were investigated. Qualities of the bread made from wheat flour blended with rice flour have been reported to be inferior to those from 100% wheat flour bread. To improve its qualities, we searched for the new-characteristic rice flours among the various kinds of newly developed rice cultivars to blend with the wheat flour for the bread preparation. The most suitable new characteristic rices are combination of purple waxy rice, high-amylose rice, and sugary rice. Specific volume of the bread from the combination of wheat and these 3 kinds of rice flours showed higher specific volume (3.93) compared with the traditional wheat/rice bread (3.58). We adopted the novel method, continuous progressive compression test, to measure the physical properties of the dough and the bread in addition to the sensory evaluation. As a result of the selection of the most suitable rice cultivars and blending ratio with the wheat flour, we could develop the novel wheat/rice bread, of which loaf volume, physical properties, and tastes are acceptable and resistant to firming on even 4 d after the bread preparation. To increase the ratio of rice to wheat, we tried to add a part of rice as cooked rice grains. The specific volume and qualities of the bread were maintained well although the rice content of total flour increased from 30% to 40%.

  12. Microstructural characteristics, mechanical and wear behaviour of aluminium matrix hybrid composites reinforced with alumina, rice husk ash and graphite

    Directory of Open Access Journals (Sweden)

    Kenneth Kanayo Alaneme

    2015-09-01

    Full Text Available The microstructural characteristics, mechanical and wear behaviour of Aluminium matrix hybrid composites reinforced with alumina, rice husk ash (RHA and graphite were investigated. Alumina, RHA and graphite mixed in varied weight ratios were utilized to prepare 10 wt% hybrid reinforced Al-Mg-Si alloy based composites using two-step stir casting. Hardness, tensile properties, scanning electron microscopy, and wear tests were used to characterize the composites produced. The results show that Hardness decreases with increase in the weight ratio of RHA and graphite in the composites; and with RHA content greater than 50%, the effect of graphite on the hardness becomes less significant. The tensile strength for the composites containing o.5wt% graphite and up to 50% RHA was observed to be higher than that of the composites without graphite. The toughness values for the composites containing 0.5wt% graphite were in all cases higher than that of the composites without graphite. The % Elongation for all composites produced was within the range of 10–13% and the values were invariant to the RHA and graphite content. The tensile fracture surface morphology in all the composites produced was identical characterized with the presence of reinforcing particles housed in ductile dimples. The composites without graphite exhibited greater wear susceptibility in comparison to the composite grades containing graphite. However the wear resistance decreased with increase in the graphite content from 0.5 to 1.5 wt%.

  13. RADISH CULTIVARS BRED AT VNIISSOK AND THEIR USE

    Directory of Open Access Journals (Sweden)

    M. I. Fedorova

    2016-01-01

    Full Text Available On the base of comparative assessment and average data estimation from 2010 to 2015, the characteristics of 11 cultivars bred at VNIISSOK were described regarding yield capacity and its components, variation, interdependencies at two sowing terms winter,spring time, direction of selection and cultivar uses at cultivar maintaining breeding program. Cultivar 'Koroleva Margo' is rather used in breeding program for yield capacity and taste qualities. Cultivar 'Sonata' is a source of such features as early maturity, valuable biochemical content and low nitrate accumulation. Cultivar 'Sofit' is known to bear early maturity and simultaneous seed maturation. 'Ariya' is a source of cylindrical root shape and early maturation. Cultivar 'Teplichnyi Gribovskyi' is used in breeding program for early maturation and simultaneous seed maturation. Cultivar 'Feya' bearsresistance to bolting and valuable biochemical substances. Cultivar 'Variant' has such features as root density, ability to grow under low lighting, short-term storability.  Purple-red with white tips is a newmade cultivar 'Mavr' suitable for breeding program for valuable biochemical content, unusual root color, also bearing male sterile forms (MS for heterosis hybrid breeding. Out of all cultivars regarded, 'Mokhovskiy' is only a genetic source to breed radish forms with edible leaves. The positive weak dependence was revealed between cultivar biochemical characteristics, root weight, dry matter  content, and nitrate content; whereas the positive middle dependence is revealed with sugar contents and negative dependence with ascorbic acid content. According to  iochemical characteristics, the best cultivar population as 'Ariya', 'Sonata' (ascorbic acid; Mavr, Sonata, Variant (dry matter, sugars have been chosen. Cultivars 'Koroleva Margo', Pheya, Sonata, Sophit, Mokhovskiy are the initial breeding accessions for selection of new cultivar population, MS and MF lines needed for heterosis.

  14. Crop response of aerobic rice and winter wheat to nitrogen, phosphorus and potassium in a double cropping system

    NARCIS (Netherlands)

    Dai, X.Q.; Zhang, H.Y.; Spiertz, J.H.J.; Yu, J.; Xie, G.H.; Bouman, B.A.M.

    2010-01-01

    In the aerobic rice system, adapted rice cultivars are grown in non-flooded moist soil. Aerobic rice may be suitable for double cropping with winter wheat in the Huai River Basin, northern China plain. Field experiments in 2005 and 2006 were conducted to study the response of aerobic rice and winter

  15. physico-chemical and grain cooking characteristics of selected rice

    African Journals Online (AJOL)

    Mgina

    Sokoine University of Agriculture, Department of Food Science and Technology,. P.O. Box 3006 ... improve the cooking quality parameters, improve production of the local rice cultivars and increase the ... Sample collection and preparation.

  16. Determination of genetic variability of Asian rice (Oryza sativa L ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... diversity and relationship among thirty-five Asian cultivars of rice including 19 aromatic, 13 non- ... are promising and effective tools for measuring genetic .... efficients were employed by using Simqual sub-program in similarity.

  17. Growth and development in Achimenes cultivars

    NARCIS (Netherlands)

    Vlahos, J.C.

    1991-01-01

    Achimenes is a herbaceous perennial of the Gesneriaceae family. Its origin is Central and South America. It has been cultivated as a pot plant since the Victorian era. Extensive hybridization has produced many attractive cultivars which have been Introduced in

  18. Cell fusion as a tool for rice improvement

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Y; Kyozuka, J; Terada, R; Nishibayashi, S; Shimamoto, K [Plantech Research Institute, Kamoshida, Midori-ku, Yokohama (Japan)

    1990-01-01

    Full text: Cell fusion offers a unique opportunity to hybridize sexually incompatible species and to mix cytoplasmic genomes in higher plants. Recent progress in plant regeneration from rice protoplasts facilitates an evaluation of the cell fusion method for rice improvement. By using electrofusion of protoplasts, we obtained hybrid/cybrid plants of the following combinations: Hybrids of rice x barnyard grass (E. oryzicola); Hybrids of rice x wild Oryza species; Cybrids of rice with transferred cms cytoplasm. For the latter, protoplasts irradiated with 70 krad x-rays were used. (author)

  19. Apple cultivars resistant to scab (Venturia inaequalis (Cke. Aderh. Part II. Winterhardiness of apple cultivars

    Directory of Open Access Journals (Sweden)

    Zbigniew Borecki

    2013-12-01

    Full Text Available The severe winter which occurred in Poland in 1986-1987 damaged the most part of scab resistant apple cultivars and selected apple hybrids. Cold hardiness studied in 1987 and 1988 showed significant differences in degree of frost injury on stem, branches, twigs and buds of apple trees. Two scab-resistance cultivars, namely Florina and Sir Prize, as well as two check culuvars, Idared and Golden Delicious, were killed by frost. Strong damages were noted in cultivars: Prima, Primula, and Priam. Lower susceptibility showed: Jonafree, Gavin, Liberty Sister and three hybrids selected from crosses of Bankroft with scab-resistant Primula. Relatively frost resistant was Novamac and three hybrids of U-breeding line: U-1101 and U-50, originated from crosses of polish culrivar Fantazja (McIntosh x Linda with Primula, Highest resistance to frost showed cultivars: Freedom. Liberty. new polish cultivar Witos (Fantazja x Primula and three hybrids: U-337, U-237 and U-1098. During the 1987 and 1988 seasons severe infection of apple trees by numerous fungi was noted. Twelve species of isolated fungi were identified as pathogens of apple trees bark and wood.

  20. Cadmium accumulation in and tolerance of rice (Oryza sativa L.) varieties with different rates of radial oxygen loss

    International Nuclear Information System (INIS)

    Wang, M.Y.; Chen, A.K.; Wong, M.H.; Qiu, R.L.; Cheng, H.; Ye, Z.H.

    2011-01-01

    Cadmium (Cd) uptake and tolerance were investigated among 20 rice cultivars based on a field experiment (1.2 mg Cd kg -1 in soil) and a soil pot trial (control, 100 mg Cd kg -1 ), and rates of radial oxygen loss (ROL) were measured under a deoxygenated solution. Significant differences were found among the cultivars in: (1) brown rice Cd concentrations (0.11-0.29 mg kg -1 ) in a field soil, (2) grain Cd tolerance (34-113%) and concentrations (2.1-6.5 mg kg -1 ) in a pot trial, and (3) rates of ROL (15-31 mmol O 2 kg -1 root d.w. h -1 ). Target hazard quotients were calculated for the field experiment to assess potential Cd risk. Significant negative relationships were found between rates of ROL and concentrations of Cd in brown rice or straw under field and greenhouse conditions, indicating that rice cultivars with higher rates of ROL had higher capacities for limiting the transfer of Cd to rice and straw. - Highlights: → There are significant differences in brown rice Cd concentrations and rates of ROL among the rice cultivars. → The rates of ROL are significantly correlated with concentrations of Cd in brown rice. → Rice cultivars with higher rates of ROL have higher capacities for limiting the transfer of Cd to rice and straw. - Rice cultivars with high rates of ROL tended to accumulate low Cd in grains.

  1. Amplifying the benefits of agroecology by using the right cultivars.

    Science.gov (United States)

    Noguera, D; Laossi, K-R; Lavelle, P; De Carvalho, M H Cruz; Asakawa, N; Botero, C; Barot, S

    2011-10-01

    Tropical soils are particularly vulnerable to fertility losses due to their low capacity to retain organic matter and mineral nutrients. This urges the development of new agricultural practices to manage mineral nutrients and organic matter in a more sustainable way while relying less on fertilizer inputs. Two methods pertaining to ecological engineering and agroecology have been tested with some success: (1) the addition of biochar to the soil, and (2) the maintenance of higher earthworm densities. However, modern crop varieties have been selected to be adapted to agricultural practices and to the soil conditions they lead to and common cultivars might not be adapted to new practices. Using rice as a model plant, we compared the responsiveness to biochar and earthworms of five rice cultivars with contrasted selection histories. These cultivars had contrasted responsivenesses to earthworms, biochar, and the combination of both. The mean relative increase in grain biomass, among all treatments and cultivars, was 94% and 32%, respectively, with and without fertilization. Choosing the best combination of cultivar and treatment led to a more than fourfold increase in this mean benefit (a 437% and a 353% relative increase in grain biomass, respectively, with and without fertilization). Besides, the more rustic cultivar, a local landrace adapted to diverse and difficult conditions, responded the best to earthworms in terms of total biomass, while a modern common cultivar responded the best in term of grain biomass. This suggests that cultivars could be selected to amplify the benefit of biochar- and earthworm-based practices. Overall, selecting new cultivars interacting more closely with soil organisms and soil heterogeneity could increase agriculture sustainability, fostering the positive feedback loop between soils and plants that has evolved in natural ecosystems.

  2. [Mechanisms of subspecies differentiation in a filial generation of rice indica-japonica hybridization under different ecological conditions].

    Science.gov (United States)

    Wang, He-Tong; Jin, Feng; Jiang, Yi-Jun; Lin, Qing-Shan; Xu, Hai; Chen, Wen-Fu; Xu, Zheng-Jin

    2013-11-01

    Indica-japonica hybridization is one of the most important breeding methods in China, whereas identifying subspecies differentiation mechanisms is the key in indica-japonica hybridization breeding. By using InDels (Insert/Deletion) and ILPs (Intron Length Polymorphism), an analysis was made on the F6 populations derived from the hybridization of indica-japonica (Qishanzhan/Akihikari) planted in Liaoning and Guangdong provinces and generated by bulk harvesting (BM), single-seed descent methods (SSD), and pedigree method (PM). No segregation distortion was observed for the BM and SSD populations. The frequency distribution of japonica kinship percentage (Dj) was concentrated in 40%-60%. The PM populations in the two provinces presented indica-deviated distribution (30%-55%), with significant difference between Guangdong (38%) and Liaoning (42%). In addition, there was a significant positive correlation between the Dj and the kinship of functional gene regions in the BM and SSD populations. However, part of the positive correlation was broken in the PM populations that showed a regular distribution in the genotype patterns of indica and japonica loci. The above results demonstrated that artificial selection could be the main factor affecting the population differentiation in indica-japonica hybridization, and, with the synergistic effect of natural selection, induced the phenomenon of segregation distortion. There existed a close relationship between the differentiation of subspecies and the important agronomic traits, which could be the main reason why indica-japonica hybridiation breeding could not achieve the expected effect of combining the two subspecies advantages.

  3. A comparative study of competitiveness between different genotypes of weedy rice (Oryza sativa) and cultivated rice.

    Science.gov (United States)

    Dai, Lei; Dai, Weimin; Song, Xiaoling; Lu, Baorong; Qiang, Sheng

    2014-01-01

    Competition from weedy rice can cause serious yield losses to cultivated rice. However, key traits that facilitate competitiveness are still not well understood. To explore the mechanisms behind the strong growth and competitive ability, replacement series experiments were established with six genotypes of weedy rice from different regions and one cultivated rice cultivar. (1) Weedy rice from southern China had the greatest impact on growth and yield of cultivated rice throughout the entire growing season. Weedy rice from the northeast was very competitive during the early vegetative stage while the competitive effects of eastern weedy rice were more detrimental at later crop-growth stages. (2) As the proportion of weedy rice increased, plant height, tillers, above-ground biomass, and yield of cultivated rice significantly declined; the crop always being at disadvantage regardless of proportion. (3) Weedy biotypes with greater diversity as estimated by their Shannon indexes were more detrimental to the growth and yield of cultivated rice. Geographic origin (latitude) of weedy rice biotype, its mixture proportion under competition with the crop and its genetic diversity are determinant factors of the outcome of competition and the associated decline in the rice crop yield. © 2013 Society of Chemical Industry. © 2013 Society of Chemical Industry.

  4. Danish apple cultivars

    DEFF Research Database (Denmark)

    Larsen, Bjarne; Pedersen, Carsten; Ørgaard, Marian

    2017-01-01

    Abstract We made a genetic analysis of about 500 apple cultivars, which either originate from Denmark or have been of greater importance in Denmark. To study the diversity and parentage among the cultivars, 15 SSR markers were used. A new PCR-based protocol for identification of S-alleles was dev......Abstract We made a genetic analysis of about 500 apple cultivars, which either originate from Denmark or have been of greater importance in Denmark. To study the diversity and parentage among the cultivars, 15 SSR markers were used. A new PCR-based protocol for identification of S...

  5. Identification of molecular markers linked to rice bacterial blight resistance genes from Oryza meyeriana

    Directory of Open Access Journals (Sweden)

    Jing WANG,Chen CHENG,Yanru ZHOU,Yong YANG,Qiong MEI,Junmin LI,Ye CHENG,Chengqi YAN,Jianping CHEN

    2015-09-01

    Full Text Available Y73 is a progeny of asymmetric somatic hybridization between Oryza sativa cv. Dalixiang and the wild rice species Oryza meyeriana. Inoculation with a range of strains of Xanthomonas oryzae pv. oryzae showed that Y73 had inherited a high level of resistance to rice bacterial blight (BB from its wild parent. An F2 population of 7125 individuals was constructed from the cross between Y73 and a BB-susceptible cultivar IR24. After testing 615 SSR and STS markers covering the 12 rice chromosomes, 186 markers were selected that showed polymorphism between Y73 and IR24. Molecular markers linked to the BB resistance genes in Y73 were scanned using the F2 population and the polymorphic markers. The SSR marker RM128 on chromosome 1, the STS marker R03D159 on chromosome 3 and the STS marker R05D104 on chromosome 5 were found to be linked to the rice BB resistance genes in Y73.

  6. Mapped clone and functional analysis of leaf-color gene Ygl7 in a rice hybrid (Oryza sativa L. ssp. indica).

    Science.gov (United States)

    Deng, Xiao-juan; Zhang, Hai-qing; Wang, Yue; He, Feng; Liu, Jin-ling; Xiao, Xiao; Shu, Zhi-feng; Li, Wei; Wang, Guo-huai; Wang, Guo-liang

    2014-01-01

    Leaf-color is an effective marker to identify the hybridization of rice. Leaf-color related genes function in chloroplast development and the photosynthetic pigment biosynthesis of higher plants. The ygl7 (yellow-green leaf 7) is a mutant with spontaneous yellow-green leaf phenotype across the whole lifespan but with no change to its yield traits. We cloned gene Ygl7 (Os03g59640) which encodes a magnesium-chelatase ChlD protein. Expression of ygl7 turns green-leaves to yellow, whereas RNAi-mediated silence of Ygl7 causes a lethal phenotype of the transgenic plants. This indicates the importance of the gene for rice plant. On the other hand, it corroborates that ygl7 is a non-null mutants. The content of photosynthetic pigment is lower in Ygl7 than the wild type, but its light efficiency was comparatively high. All these results indicated that the mutational YGL7 protein does not cause a complete loss of original function but instead acts as a new protein performing a new function. This new function partially includes its preceding function and possesses an additional feature to promote photosynthesis. Chl1, Ygl98, and Ygl3 are three alleles of the OsChlD gene that have been documented previously. However, mutational sites of OsChlD mutant gene and their encoded protein products were different in the three mutants. The three mutants have suppressed grain output. In our experiment, plant materials of three mutants (ygl7, chl1, and ygl98) all exhibited mutational leaf-color during the whole growth period. This result was somewhat different from previous studies. We used ygl7 as female crossed with chl1 and ygl98, respectively. Both the F1 and F2 generation display yellow-green leaf phenotype with their chlorophyll and carotenoid content falling between the values of their parents. Moreover, we noted an important phenomenon: ygl7-NIL's leaf-color is yellow, not yellowy-green, and this is also true of all back-crossed offspring with ygl7.

  7. Mapped clone and functional analysis of leaf-color gene Ygl7 in a rice hybrid (Oryza sativa L. ssp. indica.

    Directory of Open Access Journals (Sweden)

    Xiao-juan Deng

    Full Text Available Leaf-color is an effective marker to identify the hybridization of rice. Leaf-color related genes function in chloroplast development and the photosynthetic pigment biosynthesis of higher plants. The ygl7 (yellow-green leaf 7 is a mutant with spontaneous yellow-green leaf phenotype across the whole lifespan but with no change to its yield traits. We cloned gene Ygl7 (Os03g59640 which encodes a magnesium-chelatase ChlD protein. Expression of ygl7 turns green-leaves to yellow, whereas RNAi-mediated silence of Ygl7 causes a lethal phenotype of the transgenic plants. This indicates the importance of the gene for rice plant. On the other hand, it corroborates that ygl7 is a non-null mutants. The content of photosynthetic pigment is lower in Ygl7 than the wild type, but its light efficiency was comparatively high. All these results indicated that the mutational YGL7 protein does not cause a complete loss of original function but instead acts as a new protein performing a new function. This new function partially includes its preceding function and possesses an additional feature to promote photosynthesis. Chl1, Ygl98, and Ygl3 are three alleles of the OsChlD gene that have been documented previously. However, mutational sites of OsChlD mutant gene and their encoded protein products were different in the three mutants. The three mutants have suppressed grain output. In our experiment, plant materials of three mutants (ygl7, chl1, and ygl98 all exhibited mutational leaf-color during the whole growth period. This result was somewhat different from previous studies. We used ygl7 as female crossed with chl1 and ygl98, respectively. Both the F1 and F2 generation display yellow-green leaf phenotype with their chlorophyll and carotenoid content falling between the values of their parents. Moreover, we noted an important phenomenon: ygl7-NIL's leaf-color is yellow, not yellowy-green, and this is also true of all back-crossed offspring with ygl7.

  8. Potencial de cruzamento natural entre o arroz transgênico resistente ao herbicida glufosinato de amônio e o arroz daninho Outcrossing potential of glufosinate-resistant rice to red rice

    Directory of Open Access Journals (Sweden)

    J.A. Noldin

    2002-08-01

    Full Text Available A utilização de cultivares de arroz irrigado resistentes a herbicidas não-seletivos, como o glufosinato de amônio, pode se constituir numa alternativa de controle de arroz daninho em lavouras de arroz irrigado. O objetivo deste trabalho foi avaliar a taxa e o sentido do cruzamento natural entre plantas de uma linhagem modificada geneticamente para resistência ao herbicida glufosinato de amônio (arroz GM e ao arroz daninho. A taxa de cruzamento natural entre o arroz GM como receptor feminino e o arroz daninho como doador de pólen foi de 0,22 e 0,02%, respectivamente para os ecótipos de arroz daninho com glumas de cor palha e com glumas pretas. No caso inverso, quando o arroz daninho foi o receptor feminino e o arroz GM o doador de pólen, a taxa de cruzamento foi de 0,26 e 0,14%, para o arroz daninho com glumas palha e com glumas pretas, respectivamente. Os resultados deste estudo evidenciaram que ocorreu cruzamento natural entre o arroz GM e o arroz daninho em percentuais que variaram de 0,14 e 0,48%, respectivamente para o arroz preto e para o arroz vermelho. A fim de minimizar a possibilidade de hibridação, medidas de controle eficientes devem ser adotadas no sentido de prevenir a coincidência de floração das plantas de arroz daninho com a das plantas de arroz GM cultivado.The broad spectrum non-selective herbicide ammonium glufosinate, combined with genetically modified glufosinate-resistant rice cultivars (GM rice, may comprise a rice weed control system for red rice and other weeds that infest Brazilian rice fields. The objective of this study was to evaluate the potential for outcrossing and gene flow of GM rice to red rice. Natural outcrossing between adjacent field plots (1 m x 1 m was measured during the 1999/2000 production season in Brazil. The outcrossing rate of the GM rice as the female parent to red rice, as the pollen donor, was 0.22% for strawhull and 0.02% for the blackhull red rice, respectively. In the reciprocal

  9. Fine mapping of S37, a locus responsible for pollen and embryo sac sterility in hybrids between Oryza sativa L. and O. glaberrima Steud.

    Science.gov (United States)

    Shen, Yumin; Zhao, Zhigang; Ma, Hongyang; Bian, Xiaofeng; Yu, Yang; Yu, Xiaowen; Chen, Haiyuan; Liu, Linglong; Zhang, Wenwei; Jiang, Ling; Zhou, Jiawu; Tao, Dayun; Wan, Jianmin

    2015-11-01

    Hybrid sterility locus S37 between Oryza glaberrima and Oryza sativa results in both pollen and embryo sac sterility. Interspecific crossing between African cultivated rice Oryza glaberrima and Oryza sativa cultivars is hindered by hybrid sterility. To dissect the mechanism of interspecific hybrid sterility, we developed a near-isogenic line (NIL)-S37 using Dianjingyou1 (DJY1) as the recipient parent and an African cultivated rice variety as the donor parent. Empty pollen and embryo sac sterility were observed in F1 hybrids between DJY1 and NIL-S37. Cytological analyses showed that pollen abortion in the F1 hybrids occurred at the late binucleate stage due to a failure of starch accumulation in pollen grains. In addition, partial abortion of the embryo sac in the F1 hybrid was observed during function megaspore developing into mature embryo sac. Molecular analysis revealed that the semi-sterility was largely caused by the abortion of male and female gametophytes carrying the S37 allele from DJY1. A population of 25,600 plants derived from the hybrid DJY1/NIL-S37 was developed to fine map S37. Based on the physical location of molecular markers, S37 locus was finally delimited to a region of 205 kb on the short arm of chromosome 1 in terms of reference sequences of cv. Nipponbare. Interestingly, an about 97-kb DNA segment was deleted in the NIL-S37 based on BAC clone information of O. glaberrima. Fifty-four open reading frames (ORF) were predicted in this 205-kb region of DJY1, whereas only 31 ORFs were in that of NIL-S37. These results are valuable for cloning of S37 gene and further breaking reproductive isolation between Oryza glaberrima and Oryza sativa cultivars, as well as marker-assisted transferring of the corresponding neutral allele in rice breeding programs.

  10. Rice microstructure

    Science.gov (United States)

    An understanding of plant structure is desirable to obtain a clear idea of the overall impact of a crop. A mature rice plant consists of leafy components (left in the field post-harvest) and paddy rice (collected). The rice plant is supported by a hollow stem (culm) with leaf sheaths attached to nod...

  11. Effect of acetic acid on rice seeds coated with rice husk ash

    Directory of Open Access Journals (Sweden)

    Lizandro Ciciliano Tavares

    2013-06-01

    Full Text Available Flooded rice cultivation promotes anaerobic conditions, favoring the formation of short chain organic acids such as acetic acid, which may be toxic to the crop. The objective of this study was to evaluate the effect of acetic acid on rice seeds coated with rice husk ash. The experiment was arranged in a 2 x 5 x 5 factorial randomized design, with two cultivars (IRGA 424 and BRS Querência, five doses of coating material (0, 2, 3,4 e 5 g kg-1 seed and five concentrations of acetic acid (0, 3, 6, 9 and 12 mM, with 4 replications, totaling 50 treatments. The variables first count of germination, germination, shoot and root length, dry weight of shoots and roots were recorded. The results showed that coating rice seeds with rice husk ash up to 5 g kg-1 seed does not influence the performance of rice seeds of cultivars IRGA 424 and BRS Querência when exposed to concentrations of 12 mM acetic acid. The presence of acetic acid in the substrates used for seed germination reduced the vigor and viability of seeds of cultivars IRGA 424 and BRS Querência, as well as seedling development, affecting mainly the roots of BRS Querência.

  12. Effects of free-air CO2 enrichment on adventitious root development of rice under low and normal soil nitrogen levels

    Directory of Open Access Journals (Sweden)

    Chengming Sun

    2014-08-01

    Full Text Available Free air CO2 enrichment (FACE and nitrogen (N have marked effects on rice root growth, and numerical simulation can explain these effects. To further define the effects of FACE on root growth of rice, an experiment was performed, using the hybrid indica cultivar Xianyou 63. The effects of increasing atmospheric CO2 concentration [CO2], 200 μmol mol− 1 higher than ambient, on the growth of rice adventitious roots were evaluated, with two levels of N: low (LN, 125 kg ha− 1 and normal (NN, 250 kg ha− 1. The results showed a significant increase in both adventitious root number (ARN and adventitious root length (ARL under FACE treatment. The application of nitrogen also increased ARN and ARL, but these increases were smaller than that under FACE treatment. On the basis of the FACE experiment, numerical models for rice adventitious root number and length were constructed with time as the driving factor. The models illustrated the dynamic development of rice adventitious root number and length after transplanting, regulated either by atmospheric [CO2] or by N application. The simulation result was supported by statistical tests comparing experimental data from different years, and the model yields realistic predictions of root growth. These results suggest that the models have strong predictive potential under conditions of atmospheric [CO2] rises in the future.

  13. Early embryogenesis-specific expression of the rice transposon Ping enhances amplification of the MITE mPing.

    Directory of Open Access Journals (Sweden)

    Shota Teramoto

    2014-06-01

    Full Text Available Miniature inverted-repeat transposable elements (MITEs are numerically predominant transposable elements in the rice genome, and their activities have influenced the evolution of genes. Very little is known about how MITEs can rapidly amplify to thousands in the genome. The rice MITE mPing is quiescent in most cultivars under natural growth conditions, although it is activated by various stresses, such as tissue culture, gamma-ray irradiation, and high hydrostatic pressure. Exceptionally in the temperate japonica rice strain EG4 (cultivar Gimbozu, mPing has reached over 1000 copies in the genome, and is amplifying owing to its active transposition even under natural growth conditions. Being the only active MITE, mPing in EG4 is an appropriate material to study how MITEs amplify in the genome. Here, we provide important findings regarding the transposition and amplification of mPing in EG4. Transposon display of mPing using various tissues of a single EG4 plant revealed that most de novo mPing insertions arise in embryogenesis during the period from 3 to 5 days after pollination (DAP, and a large majority of these insertions are transmissible to the next generation. Locus-specific PCR showed that mPing excisions and insertions arose at the same time (3 to 5 DAP. Moreover, expression analysis and in situ hybridization analysis revealed that Ping, an autonomous partner for mPing, was markedly up-regulated in the 3 DAP embryo of EG4, whereas such up-regulation of Ping was not observed in the mPing-inactive cultivar Nipponbare. These results demonstrate that the early embryogenesis-specific expression of Ping is responsible for the successful amplification of mPing in EG4. This study helps not only to elucidate the whole mechanism of mPing amplification but also to further understand the contribution of MITEs to genome evolution.

  14. Controle genético e tolerância ao estresse de calor em populações híbridas e em cultivares de trigo Genetic control and tolerance to the heat stress in wheat hybrid population and cultivars

    Directory of Open Access Journals (Sweden)

    Moacil Alves de Souza

    2001-10-01

    Full Text Available O objetivo deste trabalho foi obter informações sobre o controle genético da produtividade de grãos de trigo sob condições de estresse de calor, o grau de tolerância ao estresse de calor de algumas cultivares e linhagens e a identificação de populações segregantes promissoras para a obtenção de linhagens adaptadas às condições da região central do Brasil. Foram avaliados 13 parentais e 40 populações provenientes de um dialelo parcial, nas gerações F1 e F2 em condições de campo, em Lavras e Patos de Minas, MG, com as semeaduras feitas no verão (fevereiro e no inverno (maio. Houve diferença de tolerância ao calor entre os parentais e entre as populações híbridas quanto ao caráter produção de grãos, e ambos os efeitos aditivos e não-aditivos foram importantes no controle genético deste caráter na presença ou ausência de calor. Apesar da ocorrência de interações populações x épocas de semeadura, a alta repetibilidade dos efeitos da capacidade geral de combinação permite inferir a possibilidade de acelerar os programas de melhoramento na região, efetuando-se a seleção tanto na época de verão quanto no inverno.The objective of this work was to get information about the genetic control of the grain yield under heat stress conditions, the tolerance of cultivar and the identification of promising segregation populations for selections of lines adapted to the conditions of the central region of Brazil. Thirteen parents and 40 populations in F1 and F2 generations derived by partial diallel crosses were evaluated. The experiments were conducted under field conditions in Lavras and Patos de Minas, MG, Brazil, sowing the seeds in the summertime (February and in the winter (May. There was difference of heat tolerance among parents and hybrid populations for grain yield character, and both additive and non-additive effects were important in the genetic control of grain yield character in the presence or absence

  15. Physicochemical and antioxidative properties of black, brown and red rice varieties of northern Thailand

    Directory of Open Access Journals (Sweden)

    Noppawat Pengkumsri

    2015-06-01

    Full Text Available Rice, the seed of Oryza species, is the major cereal crop in most of the developing countries. Nearly 95% of global rice production is done in Asian countries, and about half of the world’s population consumes it. Some speciality rices are not commonly consumed. Colored rice is one of such variety. In these varieties, high amounts of anthocyanin pigment are deposited in the rice coat to form its black (also known as purple, brown and red colors. Minimum studies are there to explain the properties of these rice varieties of Thailand. Thus, the current study was aimed to assess the physicochemical and antioxidative properties of three rice varieties (Chiang Mai Black rice, Mali Red rice and Suphanburi-1 Brown rice of different cultivars of northern Thailand. Rice bran extracts of these three cultivars were prepared with different solvents (polar and non-polar for the evaluation of total phytochemical content and anti-oxidant free-radical-scavenging properties. Chiang Mai Black rice contained higher concentration of phenolic acid, flavonoids, and anthocyanins (Cyanidin 3-glucoside, peonidin 3-glucoside, cyanidin chloride. Chiang Mai Black rice is richer in free-radical-scavenging compounds and activities than the other tested varieties. Polar extractions of rice bran are high in anti-oxidative compounds and activities than non-polar extractions.

  16. Linkage relationship between semi-dwarfing gene sd-1 and gene for grain shattering in rice

    International Nuclear Information System (INIS)

    Oba, S.; Kikuchi, F.

    1990-01-01

    Full text: Most semidwarf rice cultivars carry the same gene sd-1. We observed an association between semi-dwarfness and grain shattering in isogenic lines carrying sd-1 from different sources in the background of the Japanese tall cultivar 'Norin 28'. The shattering was found to be caused by a single recessive gene, sh-2, linked to the sd-1 locus. The shattering gene seems to have been transmitted to many semi-dwarf cultivars together with sd-1, not only from 'Dee-geo-woo-gen' but also from the indica-cultivar 'Ai-jio-nan-te' and the japonica cultivar 'Shiranui'. (author)

  17. Elegant lady a pink longiflorum lily cultivar suitable for cut flower forcing

    NARCIS (Netherlands)

    Lim Ki-Byung,; Tuyl, van J.M.

    2004-01-01

    A new pink longiflorum (Lilium longiflorum x (L. longiforum x L. rubellum)) lily cultivar was obtained by integrated intersectional hybridization techniques. The F1 intersectional hybrid was obtained by crossing between L. longiflorum 'Gelria' and wild type L. rubellum. Since the F1 hybrid was

  18. Rice methylmercury exposure and mitigation: a comprehensive review.

    Science.gov (United States)

    Rothenberg, Sarah E; Windham-Myers, Lisamarie; Creswell, Joel E

    2014-08-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice (Orzya sativa) cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, p<0.001). However, rice percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effects of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, in order to minimize methylmercury exposure through rice ingestion. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. The effects of chilling stress after anthesis on the physicochemical properties of rice (Oryza sativa L) starch.

    Science.gov (United States)

    Zhu, Dawei; Wei, Haiyan; Guo, Baowei; Dai, Qigen; Wei, Cunxu; Gao, Hui; Hu, Yajie; Cui, Peiyuan; Li, Min; Huo, Zhongyang; Xu, Ke; Zhang, Hongcheng

    2017-12-15

    This study investigates the effect of chilling stress, over a period of three days after anthesis, on the physicochemical properties of starches derived from six rice cultivars. Chilling stress significantly affected the grain characteristics and physicochemical properties of rice starches, except for those of two varieties, NJ 9108 and ZD 18. In the other four rice cultivars subjected to chilling stress, the content of medium, and large sized granules showed a decrease, and an increase, respectively. Amylose content increased as a result of chilling stress, thereby resulting in starch with a lower swelling power, water solubility, and higher retrogradation enthalpy and gelatinization temperature. Chilling stress led to deterioration of cooked rice quality as determined by the pasting properties of starch. This study indicated that among the cultivars studied, the two rice varieties most resistant to chilling stress after rice anthesis were NJ 9108 and ZD 18. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Inheritance of Gelatinization Temperature and Gel Consistency in Rice (Oryza sativa L.)

    Science.gov (United States)

    Kiani; Sh.; Ranjbar, G. A.; Kazemitabar, S. K.; Jelodar, N. B.; Nowrozi, M.; Bagheri, N.

    Gelatinization Temperature (GT) and Gel Consistency (GC) are important traits in determination of rice quality. In present study four rice cultivars namely Sang-e-Tarrom, Gerdeh, IR229 and IRRI2 have been utilized in hybridization as parents. In order to know about genetic characteristics and inheritance of the related traits, direct and reciprocal crosses have been conducted between parents Sang-e-Tarrom and Gerdeh and between IR229 and IRRI2. Inheritance of related traits have been studied in direct and reciprocal hybridizations for hard, intermediate and soft GC, low and high GT. For these evaluations P1, P2, F1, F2, BC1, BC2 generations and their reciprocal crosses have been utilized in present study. Results showed that gene hard GC dominates on intermediate and soft and also intermediate GT dominates on low. From direct and reciprocal crosses Gerdeh x Sang-e-Tarrom and IR229 x IRRI2 have been illustrated that GC and GT expressions are under monogenic control of one major gene corresponding with several modifier genes. Gene dosage effects play a tremendously important and effective role in segregation production among traits. Regarding to the obtained results selections can effectively be performed in later segregation generations for GC and in early generations for GT.

  1. analysis of the productivity of upland rice and cover crops in relay ...

    African Journals Online (AJOL)

    AISA

    system will be identified. MATERIALS AND METHODS. FIELD EXPERIMENT. Field experiments, comprising monocultures of two rice cultivars, two cover crop ..... Value of SLAnew of the cultivars fluctuated around 23 m2 kg-1, with the values for V4 slightly higher than for WAB56-50 during the first part of development (Table ...

  2. Main biological characters of series of mutant waxy rices developed from irradiation-induced mutation

    International Nuclear Information System (INIS)

    Huang Ronghua; Zhang Shubiao; Zhang Qingqi; Yang Rencui; Lin Jinhu

    2008-01-01

    The main biological characters of the waxy male sterile lines, maintainer lines, restorer lines and waxy hybrids which had been developed by radiation-induced mutation were studied, and the grain quality of the waxy hybrids were analyzed as well. Sesults indicated that the mutant waxy rice had the same growth duration, similar agronomic characters, panicle and spikelet traits as parent. The waxy male-sterile line had the same pollen sterility characteristic as its parent male-sterile line. The waxy hybrid rice retained the yield potential as original hybrid rice, and the grain quality of the waxy hybrids was similar to the conventional waxy rice Ejinnuo 6. (authors)

  3. Pessegueiro: cultivar BRS kampai

    Directory of Open Access Journals (Sweden)

    Maria do Carmo Bassols Raseira

    2010-12-01

    Full Text Available RESUMO O programa de Melhoramento Genético de Pessegueiros da Embrapa Clima Temperado tem, entre seus objetivos, a obtenção de cultivares produtoras de frutas para consumo in natura, com características que satisfaçam às exigências dos consumidores. Alguns dos grandes centros consumidores, como é o caso de São Paulo e Curitiba, preferem pêssegos de polpa branca e sabor doce. A cultivar BRS Kampai, obtida de um cruzamento entre 'Chimarrita' e 'Flordaprince', alia a baixa necessidade em frio, o que é uma vantagem em regiões subtropicais, à boa aparência, com sabor superior a qualquer um dos parentais. A colheita dos frutos desta cultivar inicia-se geralmente, em meados de novembro, em Pelotas-RS (em Atibaia, São Paulo, inicia-se na segunda quinzena de outubro, poucos dias antes das cultivares Rubimel (polpa amarela e Premier (polpa branca, sendo ótima substituta para esta última.

  4. Maize cultivar performance under diverse organic production systems

    Science.gov (United States)

    Maize cultivar performance can vary widely among different production systems. The need for high-performing hybrids for organic systems with wide adaptation to various macroenvironments is becoming increasingly important. The goal of this study was to characterize inbred lines developed by distinc...

  5. Role of mutation in improving rice productivity-retrospect and prospect

    International Nuclear Information System (INIS)

    Chakrabarti, S.N.

    1996-01-01

    With the recent development in the hybrid rice breeding and rice biotechnology, the role of mutation induction in genetic manipulation deserves special importance. In many instances, the major constraint in hybrid rice breeding is lack of suitable cytoplasmic male sterile line. There is immense scope for developing such male sterile lines through use of mutation tool. In this paper improvement of rice productivity with particular reference to attainments in India have been discussed. 50 refs., 2 figs., 6 tabs

  6. UV-irradiation enhances rice allelopathic potential in rhizosphere soil

    DEFF Research Database (Denmark)

    Mahmood, Khalid; Khan, Muhammad Bismillah; Song, Yuan Yuan

    2013-01-01

    Ultraviolet-B radiation is rising continuously due to stratospheric ozone depletion over temperate latitudes. This study investigated effects of UV exposure on rice allelopathic potentials. For this purpose, two rice (Oryza sativa L.) cultivars BR-41 (high allelopathic = able to inhibit neighboring...... grass and lettuce). These bioassays showed significant inhibition in lettuce and barnyard growth after UV in both rice cultivars. Interestingly, Huajingxian, which did not exhibit allelopathic potential in absence of UV showed significant inhibition after UV exposure. Phenolics, enzymes activities...... and genes responsible for biosynthesis of allelopathic compounds were examined after UV exposure. Phenolic compounds accumulated in rice leaves were quantified through HPLC analysis. They were significantly higher in BR-41 leaves after UV exposure. Enzyme activities (PAL and C4H) were significantly higher...

  7. Genetic diversity associated with conservation of endangered Dongxiang wild rice (Oryza rufipogon)

    Science.gov (United States)

    The wild progenitor species (Oryza rufipogon) of Asian cultivated rice (O. sativa) is located in Dongxiang county, China where it is considered the northernmost range worldwide. Nine ex situ and three in situ populations of the Dongxiang wild rice (DXWR) and four groups of modern cultivars were geno...

  8. Disentangling the effect of environmental factors on yield and nitrogen uptake of irrigated rice in Asia

    NARCIS (Netherlands)

    Jing, Q.; Bouman, B.A.M.; Keulen, van H.; Hengsdijk, H.; Cao, W.; Dai, T.

    2008-01-01

    Rice yield is the result of the interaction between genotype (cultivar characteristics), environment (climate and soil conditions), and management. Few studies have attempted to isolate the contribution of each of these factors. Here the rice growth model ORYZA2000 was used to analyse the variation

  9. Polishing and parboiling effect on the nutritional and technological properties of pigmented rice

    Science.gov (United States)

    This study aims to evaluate the effects of polishing and parboiling on proximate composition, structure, phenolic compounds, antioxidant activity, cooking time and hardness of IAC-600 black rice cultivar and MPB-10 red rice lineage. Proximate analysis and light micrographs revealed higher migration ...

  10. Super Rice Cropping Will Enhance Rice Yield and Reduce CH4 Emission: A Case Study in Nanjing, China

    Directory of Open Access Journals (Sweden)

    Yu JIANG

    2013-11-01

    Full Text Available A pot experiment was performed to learn the differences in plant productivity and CH4 emission between two rice cultivars, super rice variety Ningjing 1 and traditional variety Zhendao 11, which were currently commercially applied in Nanjing, China. Similar seasonal changes of CH4 emission fluxes and soil solution CH4 contents were found between the tested cultivars. Although there was no significant difference in plant biomass production between the cultivars, the grain yield of Ningjing 1 was significantly higher by 35.0% (P < 0.05 than that of Zhendao 11, whereas the total CH4 emission from Ningjing 1 was 35.2% lower (P < 0.05. The main difference in the amounts of CH4 emission between the cultivars occurred in the period from the tillering stage to the heading stage. The biomass-scaled and yield-scaled CH4 emissions were respectively 3.8 and 5.2 mg/g for Ningjing 1, significantly lower than those for Zhendao 11 (7.4 and 12.8 mg/g, respectively. According to the relationships between the plant growth characteristics and the CH4 emission, a stronger root system contributed mainly to the lower CH4 emission of Ningjing 1, as compared with Zhendao 11. Our results demonstrated that super rice has advantages not only in grain productivity but also in CH4 emission mitigation. Further expansion of super rice cropping will enhance rice yield and reduce greenhouse gas emission in China.

  11. Rice methylmercury exposure and mitigation: a comprehensive review

    Science.gov (United States)

    Rothenberg, Sarah E.; Windham-Myers, Lisamarie; Creswell, Joel E.

    2014-01-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice (Orzya sativa) cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, price percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effects of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, in order to minimize methylmercury exposure through rice ingestion.

  12. Synthesis composite hydrogels from inorganic-organic hybrids based on leftover rice for environment-friendly controlled-release urea fertilizers.

    Science.gov (United States)

    Zhou, Tao; Wang, Yan; Huang, Sheng; Zhao, Youcai

    2018-02-15

    Nearly 1.3 billion tons of food are discarded annually in the production process. In this study, a novel slow-release nitrogen fertilizer with water absorbency was developed using leftover rice and crosslinking methods. Urea was incorporated as the nitrogen source in a leftover rice-g-poly(acrylic acid)/montmorillonite (LR-g-PAA/MMT) network, and then the leftover rice-g-poly(acrylic acid)/montmorillonite/Urea (LR-g-PAA/MMT/Urea) retained in the soil, and used as the loss control agent for water and nutrients. Variables including concentrations of acrylic acid, montmorillonite, N,N´-methylenebis acrylamide (MBA), and potassium persulfate (KPS) were investigated. Samples were with a water absorbency of 102.6g/g in distilled water and 25.1g/g in 1.0wt% NaCl solution under optimized conditions. Swelling measurements and water-retention indicated that higher-covalent cations would aggregate the hydrogels and decrease swelling. Investigating leaching behavior showed that these samples have the potential to carry the necessary nitrogen (N). The results demonstrated that the LR-g-PAA/MMT/Urea had a low leaching losses of N (19.7%) compared with pure urea (52.3%). Therefore, the developed fertilizer may be widely applicable in agriculture and horticulture, and could provide a new platform for reusing leftover rice. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Black rice as a functional food in Indonesia

    Directory of Open Access Journals (Sweden)

    Rarastoeti Pratiwi

    2017-03-01

    Full Text Available There are many local black rice cultivars in Indonesia, yet only a few of these are formally describedin the literature.It has been reportedthat black rice has many phytochemicalvariants which may contribute to its use as a functional food, including nutraceuticals andsecondary metabolites such as anthocyanin, oryzanol,and more.The purpose of this article wasto review literature describing black rice cultivars from Indonesia, with a particular focuson its potential use as a functional food.Our literature search revealed several articles that describe black rice in relation to its nutraceuticalproperties and its role in reducing non-communicable diseases. Other studies describe the diversity of local pigmented rice and its potentialfor lowering the risk of hyperlipidemia,hyperglycemia,and for cancer prevention. Black rice has been described as a functional food in several countries;however,there is great diversity among cultivars and further research on Indonesian varieties will determine whether local variants are candidates as well for the development of functional foods.

  14. Effectiveness of sodium azide alone compared to sodium azide in combination with methyl nitrosurea for rice mutagenesis

    Science.gov (United States)

    Rice seeds of the temperate japonica cultivar Kitaake were mutagenized with sodium azide alone and in combination with methyl nitrosourea. Using the reduced representation sequencing method Restriction Enzyme Sequence Comparative Analysis (RESCAN), the mutation densities, types and local sequence co...

  15. Rainfed Rice Production and there Germplasm Development in Kenya

    International Nuclear Information System (INIS)

    Onyango, J.C.; Onyango, M.O.A.

    1999-01-01

    Rice (Oryza Sativa L.) has been grown in Kenya for several centuries and during this time has been locally selected by farmers for adaptation in the dry climate of Kenya highlands and coastal region. this history of selection by farmers has led to the concentration of genetic information for performance under drought conditions in locally-adapted rice types. Since water availability affects many processes in plants, drought tolerance is a complex character and due to the complex nature of the drought tolerance limited progress has been made in breeding for drought tolerance using simple screening methods. To produce drought tolerant cultivars, characters can used as parents in a breeding program, this is a two step process. Obviously, the root system is central to drought tolerance. The root system must be able to remove water efficiently from soils with low moisture and withstand the dynamics of soil during drought conditions will prevent stomata closure and maximise photosynthesis which is essential for high crop production. Over 365 cultivars of rainfed rice have been identified in Kenya and can be used in the two step process as source material for identifying characters related to drought tolerance and as parental lines. To advance the first step, research was conducted to identify drought tolerance characters in rainfed cultivars from Kenya. The study had a total of 580 mm of rainfall which was below the mean precipitation requirement of 750 mm. The drought sensitive variety IR20 was compared with drought tolerant IR52 and five KR (Kenya Rice) KR21, KR22, KR35,KR108 and KR135 cultivars. Plant biomass, plant height, leaf area, leaf length, protein: chlorophyll content ratio and grain yield were affected by limiting water availability and differences between cultivars were noted. The protein to chlorophyll ratio in leaves in the KR. cultivars increase from 18.4 to 28.0 as water deficient increases from -0.8 mpa to -1.4 Mpa allowing these cultivars to maintain

  16. Study on Analysis of Variance on the indigenous wild and cultivated rice species of Manipur Valley

    Science.gov (United States)

    Medhabati, K.; Rohinikumar, M.; Rajiv Das, K.; Henary, Ch.; Dikash, Th.

    2012-10-01

    The analysis of variance revealed considerable variation among the cultivars and the wild species for yield and other quantitative characters in both the years of investigation. The highly significant differences among the cultivars in year wise and pooled analysis of variance for all the 12 characters reveal that there are enough genetic variabilities for all the characters studied. The existence of genetic variability is of paramount importance for starting a judicious plant breeding programme. Since introduced high yielding rice cultivars usually do not perform well. Improvement of indigenous cultivars is a clear choice for increase of rice production. The genetic variability of 37 rice germplasms in 12 agronomic characters estimated in the present study can be used in breeding programme

  17. Radiation use efficiency of rice under different planting methods and environmental conditions

    International Nuclear Information System (INIS)

    Apakupakul, R.

    1995-01-01

    Radiation use efficiency is an important parameter which has often been used in many crop growth models to estimate total biomass and yield. Studies of the relationships between above-ground biomass and accumulative absorbed photosynthetically active radiation (PARa, MJ/square m) of rice were examined both on-farms and on-station in Phatthalung. Planting methods were wet-sown and transplanted rice for Suphanburi 90 in the 1993 dry season and Chieng in the 1993-94 wet season. Solar radiation of the two growing seasons were calculated from climatic data. The objectives of this experiment were (1) to know the pattern of relationship between above-ground biomass and accumulative absorbed PAR of rice cultivars grown in South Thailand, (2) to compare the radiation use efficiency of rice cultivars under different planting methods and (3) to obtain the primary data for rice growth modelling in the southern climate. Results presented that only the duration of first growing period up to stem elongation in both cultivars, above-ground biomass and leaf area index were higher in wet-sown than in transplanted rice. Relationship between above-ground biomass accumulation through growing period and accumulative absorbed PAR was in positive linear regression with R*[2)0.85. Erect leaf of Suphanburi 90 had a radiation use efficiency (RUE, g/MJ) higher than non-erect leaf of Chieng. A problem of weed infestation in wet-sown rice in both cultivars had an effect on the RUE which were highly significant lower than transplanted rice. The Rue of wet-sown and transplanted rice were 2.77 and 3.20 g/MJ, respectively for Suphanburi 90, 2.13 and 2.67 g/MJ for Chieng. These results suggest that when dealing with radiation use efficiency in the rice growth modelling the differences of cultivars and planting methods should be taken into consideration

  18. Glufosinate herbicide-tolerant (LibertyLink) rice vs. conventional rice in diets for growing-finishing swine.

    Science.gov (United States)

    Cromwell, G L; Henry, B J; Scott, A L; Gerngross, M F; Dusek, D L; Fletcher, D W

    2005-05-01

    Genetically modified (GM) rice (LibertyLink, event LLRICE62) that is tolerant to glufosinate ammonium (Liberty) herbicide was compared with a near-isogenic (NI) conventional medium-grain brown rice (cultivar, Bengal) and a commercially milled long-grain brown rice in diets for growing-finishing pigs. The GM and NI rice were grown in 2000. The GM rice was from fields treated (GM+) or not treated (GM-) with glufosinate herbicide. The GM- and NI rice were grown using herbicide regimens typical of southern United States rice production practices. The four rice grains were similar in composition. Growing-finishing pigs (n = 96) were fed fortified rice-soybean meal diets containing the four different rice grains from 25 to 106 kg BW. Diets contained 0.99% lysine initially (growing phase), with lysine decreased to 0.80% (early finishing phase) and 0.65% (late finishing phase), when pigs reached 51 and 77 kg, respectively. The percentage of rice in the four diets was constant during each of the three phases (72.8, 80.0, and 85.8% for the growing, early-finishing, and late-finishing phases, respectively). There were six pen replicates (three pens of barrows and three pens of gilts) and four pigs per pen for each dietary treatment. All pigs were slaughtered at the termination of the study to collect carcass data. At the end of the 98-d experiment, BW gain, feed intake (as-fed basis), and feed:gain ratio did not differ (P > 0.05) for pigs fed the GM+ vs. conventional rice diets, but growth performance traits of pigs fed the GM+ rice diets were superior (P glufosinate herbicide-tolerant rice was similar in composition and nutritional value to conventional rice for growing-finishing pigs.

  19. Low pH-induced changes of antioxidant enzyme and ATPase activities in the roots of rice (Oryza sativa L. seedlings.

    Directory of Open Access Journals (Sweden)

    Yi-Kai Zhang

    Full Text Available Soil acidification is the main problem in the current rice production. Here, the effects of low pH on the root growth, reactive oxygen species metabolism, plasma membrane functions, and the transcript levels of the related genes were investigated in rice seedlings (Oryza sativa L. in a hydroponic system at pH 3.5, 4.5, and 5.5. There were two hybrid rice cultivars in this trial, including Yongyou 12 (YY12, a japonica hybrid and Zhongzheyou 1 (ZZY1, an indica hybrid. Higher H+ activity markedly decreased root length, the proportion of fine roots, and dry matter production, but induced a significant accumulation of hydrogen peroxide (H2O2, and led to serious lipid peroxidation in the roots of the two varieties. The transcript levels of copper/zinc superoxide dismutase 1 (Cu/Zn SOD1, copper/zinc superoxide dismutase 2 (Cu/Zn SOD2, catalase A (CATA and catalase B (CATB genes in YY12 and ZZY1 roots were significantly down-regulated after low pH exposure for two weeks. Meanwhile, a significant decrease was observed in the expression of the P-type Ca2+-ATPases in roots at pH 3.5. The activities of antioxidant enzymes (SOD, CAT and plasma membrane (PM Ca2+-ATPase in the two varieties were dramatically inhibited by strong rhizosphere acidification. However, the expression levels of ascorbate peroxidase 1 (APX1 and PM H+-ATPase isoform 7 were up-regulated under H+ stress compared with the control. Significantly higher activities of APX and PM H+-ATPase could contribute to the adaptation of rice roots to low pH.

  20. Effects of partially replacing dietary soybean meal or cottonseed meal with completely hydrolyzed feather meal (defatted rice bran as the carrier) on production, cytokines, adhesive gut bacteria, and disease resistance in hybrid tilapia (Oreochromis niloticus ♀ × Oreochromis aureus ♂).

    Science.gov (United States)

    Zhang, Zhen; Xu, Li; Liu, Wenshu; Yang, Yalin; Du, Zhenyu; Zhou, Zhigang

    2014-12-01

    We formulated experimental diets for hybrid tilapia to investigate the effects of replacing dietary soybean meal (SBM) or cottonseed meal (CSM) by completely hydrolyzed feather meal (defatted rice bran as the carrier; abbreviated as CHFM), with emphasis on fish growth, the composition of adhesive gut bacteria, intestinal and hepatic immune responses, and disease resistance. A series of four isonitrogenous (33% crude protein) and isolipidic (6% crude lipid) diets were formulated to replace the isonitrogenous percentages of CSM or SBM by 6% or 12% CHFM. Quadruplicate groups of healthy and uniformly sized hybrid tilapia were assigned to each experimental diet. Fish were hand fed three times a day for 8 weeks at a rearing temperature of 25-28 °C. The growth performance of hybrid tilapia fed diets with partial replacement of dietary SBM or CSM with CHFM was comparable to the group of fish fed the control diet. The CHFM-containing diets affected the intestinal autochthonous bacterial community in similar ways. All CHFM-containing diets stimulated the expression of heat shock protein 70 in the intestine but suppressed its expression in the liver. Only the CHFM6/SBM diet stimulated the expression of interleukin-1β in intestine, and no effects were observed in all diets to the expression of interleukin-1β in liver. Thus, regarding the immune response in the intestine and liver, CHFM is a good alternative protein source that induces less stress in the host. CHFM did not affect disease resistance to Aeromonas hydrophila infection in hybrid tilapia. These data suggest that CHFM is a good alternative to partially replace SBM and CSM in tilapia feed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Proposal of a growth chamber for growing Super-Dwarf Rice in Space Agriculture

    Science.gov (United States)

    Hirai, Hiroaki; Kitaya, Yoshiaki; Tsukamoto, Koya; Yamashita, Youichirou; Hirai, Takehiro

    Space agriculture needs to be considered to supply food for space crew who stay in space over an extended time period. So far crops such as wheat, onion, oat, pea and lettuce grew to explore the possibility of space agriculture. Although rice is a staple food for most of the world, research on rice cultivation in space has not been done much. Rice grains are nutrient-rich with carbohydrate, protein and dietary fiber. Moreover, rice is a high yield crop and harvested grains have a long shelf life. However, the plant height of standard rice cultivars is relatively long, requiring much space. In addition, rice plants require higher light intensities for greater yield. For these reasons, it is difficult to establish facilities for rice culture in a limited space with a low cost. We propose to employee a super-dwarf cultivar and a small growth chamber with a new type of LEDs. The super-dwarf rice is a short-grain japonica variety and the plant height is approximately 20 cm that is one-fifth as tall as standard cultivars. The LED light used as a light source for this study can provide full spectrum of 380 nm to 750 nm. Air temperature and humidity were controlled by a Peltier device equipped in the chamber. The characteristics of the new type of LEDs and other equipments of the chamber and the ground based performance of super-dwarf rice plants grown in the chamber will be reported.

  2. Stomatal conductance, mesophyll conductance, and transpiration efficiency in relation to leaf anatomy in rice and wheat genotypes under drought.

    Science.gov (United States)

    Ouyang, Wenjing; Struik, Paul C; Yin, Xinyou; Yang, Jianchang

    2017-11-02

    Increasing leaf transpiration efficiency (TE) may provide leads for growing rice like dryland cereals such as wheat (Triticum aestivum). To explore avenues for improving TE in rice, variations in stomatal conductance (gs) and mesophyll conductance (gm) and their anatomical determinants were evaluated in two cultivars from each of lowland, aerobic, and upland groups of Oryza sativa, one cultivar of O. glaberrima, and two cultivars of T. aestivum, under three water regimes. The TE of upland rice, O. glaberrima, and wheat was more responsive to the gm/gs ratio than that of lowland and aerobic rice. Overall, the explanatory power of the particular anatomical trait varied among species. Low stomatal density mostly explained the low gs in drought-tolerant rice, whereas rice genotypes with smaller stomata generally responded more strongly to drought. Compared with rice, wheat had a higher gm, which was associated with thicker mesophyll tissue, mesophyll and chloroplasts more exposed to intercellular spaces, and thinner cell walls. Upland rice, O. glaberrima, and wheat cultivars minimized the decrease in gm under drought by maintaining high ratios of chloroplasts to exposed mesophyll cell walls. Rice TE could be improved by increasing the gm/gs ratio via modifying anatomical traits. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  3. Over-expression of a NAC 67 transcription factor from finger millet (Eleusine coracana L.) confers tolerance against salinity and drought stress in rice.

    Science.gov (United States)

    Rahman, Hifzur; Ramanathan, Valarmathi; Nallathambi, Jagedeeshselvam; Duraialagaraja, Sudhakar; Muthurajan, Raveendran

    2016-05-11

    NAC proteins (NAM (No apical meristem), ATAF (Arabidopsis transcription activation factor) and CUC (cup-shaped cotyledon)) are plant-specific transcription factors reported to be involved in regulating growth, development and stress responses. Salinity responsive transcriptome profiling in a set of contrasting finger millet genotypes through RNA-sequencing resulted in the identification of a NAC homolog (EcNAC 67) exhibiting differential salinity responsive expression pattern. Full length cDNA of EcNAC67 was isolated, characterized and validated for its role in abiotic stress tolerance through agrobacterium mediated genetic transformation in a rice cultivar ASD16. Bioinformatics analysis of putative NAC transcription factor (TF) isolated from a salinity tolerant finger millet showed its genetic relatedness to NAC67 family TFs in related cereals. Putative transgenic lines of rice over-expressing EcNAC67 were generated through Agrobacterium mediated transformation and presence/integration of transgene was confirmed through PCR and southern hybridization analysis. Transgenic rice plants harboring EcNAC67 showed enhanced tolerance against drought and salinity under greenhouse conditions. Transgenic rice plants were found to possess higher root and shoot biomass during stress and showed better revival ability upon relief from salinity stress. Upon drought stress, transgenic lines were found to maintain higher relative water content and lesser reduction in grain yield when compared to non-transgenic ASD16 plants. Drought induced spikelet sterility was found to be much lower in the transgenic lines than the non-transgenic ASD16. Results revealed the significant role of EcNAC67 in modulating responses against dehydration stress in rice. No detectable abnormalities in the phenotypic traits were observed in the transgenic plants under normal growth conditions. Results indicate that EcNAC67 can be used as a novel source for engineering tolerance against drought and salinity

  4. Genetic analysis of a hybrid sterility gene that causes both pollen and embryo sac sterility in hybrids between Oryza sativa L. and Oryza longistaminata.

    Science.gov (United States)

    Chen, H; Zhao, Z; Liu, L; Kong, W; Lin, Y; You, S; Bai, W; Xiao, Y; Zheng, H; Jiang, L; Li, J; Zhou, J; Tao, D; Wan, J

    2017-09-01

    Oryza longistaminata originates from African wild rice and contains valuable traits conferring tolerance to biotic and abiotic stress. However, interspecific crosses between O. longistaminata and Oryza sativa cultivars are hindered by reproductive barriers. To dissect the mechanism of interspecific hybrid sterility, we developed a near-isogenic line (NIL) using indica variety RD23 as the recipient parent and O. longistaminata as the donor parent. Both pollen and embryo sac semi-sterility were observed in F 1 hybrids between RD23 and NIL. Cytological analysis demonstrated that pollen abortion in F 1 hybrids occurred at the early bi-nucleate stage due to a failure of the first mitosis in microspores. Partial embryo sacs in the F 1 hybrids were defective during the functional megaspore formation stage. Most notably, nearly half of the male or female gametes were aborted in heterozygotes S40 i S40 l , regardless of their genotypes. Thus, S40 was indicated as a one-locus sporophytic sterility gene controlling both male and female fertility in hybrids between RD23 and O. longistaminata. A population of 16 802 plants derived from the hybrid RD23/NIL-S40 was developed to fine-map S40. Finally, the S40 locus was delimited to an 80-kb region on the short arm of chromosome 1 in terms with reference sequences of cv. 93-11. Eight open reading frames (ORFs) were localized in this region. On the basis of gene expression and genomic sequence analysis, ORF5 and ORF8 were identified as candidate genes for the S40 locus. These results are helpful in cloning the S40 gene and marker-assisted transferring of the corresponding neutral allele in rice breeding programs.

  5. Vigor, produtividade e qualidade de frutos de quatro tangerineiras e híbridos sobre quatro porta-enxertos Vegetative growth, yield and fruit quality of four mandarin and hybrid cultivars on four rootstocks

    Directory of Open Access Journals (Sweden)

    Eduardo Sanches Stuchi

    2008-09-01

    Full Text Available Avaliaram-se o desenvolvimento vegetativo, a produção e a qualidade de frutos das cultivares-copa 'Swatow' (Citrus reticulata Blanco, 'Ellendale' [C. reticulata x C. sinensis (L. Osbeck], 'Fortune' (C. clementina hort. ex Tanaka x C. tangerina hort. ex Tanaka e 'Nova' [C. clementina x (C. paradisi Macfad. x C. reticulata] sobre limoeiro 'Cravo' (C. limonia Osbeck, citrumeleiro 'Swingle' (C. paradisi x P. trifoliata (L. Raf., tangelereiro 'Orlando' (C. reticulata x C. paradisi e tangerineira 'Cleópatra' (C. reshni hort. ex Tanaka, de 2000 a 2006. O experimento foi instalado em Bebedouro-SP, em outubro de 1997. As variáveis analisadas foram: produção anual e produção acumulada de todas as cultivares para todos os anos (2000 a 2006, qualidade de frutos em 2005 e 2006 (massa, sólidos solúveis totais, acidez total, ratio, volume da copa, diâmetro do tronco da copa, eficiência de produção (Kg frutos/m³ copa e índice de alternância de produção. A produção acumulada e a qualidade de frutos das cultivares testadas não foram influenciadas pelos porta-enxertos. O citrumelo 'Swingle' induziu menor porte às plantas das cultivares-copa. O tangelo 'Nova' apresentou características adequadas à comercialização in natura. A tangerineira 'Swatow' produziu frutos de qualidade semelhante aos de tangerineira 'Ponkan'. O tangor 'Ellendale' e a tangerineira 'Fortune' apresentaram produção de frutos baixa e irregular.Plant growth, yield, and fruit quality of 'Swatow' (Citrus reticulata Blanco, 'Ellendale' (C. reticulata x Citrus sinensis L. Osbeck, 'Fortune' (Citrus clementina Hort. ex Tan. x Citrus tangerina Hort. ex Tan. e 'Nova' [(C. clementina x (Citrus paradisi Macf. x C. reticulata] mandarins budded on 'Rangpur' lime (C. limonia Osbeck, 'Swingle' citrumelo (P. trifoliata Raf. x C. paradisi Macf., 'Orlando' tangelo (C. reticulata Blanco x C. paradisi Macf., and 'Cleopatra' mandarin (Citrus reshni Hort. ex Tan. were evaluated, from 2000

  6. Field trial of GABA-fortified rice plants and oral administration of milled rice in spontaneously hypertensive rats.

    Science.gov (United States)

    Kowaka, Emi; Shimajiri, Yasuka; Kawakami, Kouhei; Tongu, Miki; Akama, Kazuhito

    2015-06-01

    Hypertension is one of the most critical risk factors accompanying cardiovascular diseases. γ-Aminobutyric acid (GABA) is a non-protein amino acid that functions as a major neurotransmitter in mammals and also as a blood-pressure lowering agent. We previously produced GABA-fortified rice lines of a popular Japonica rice cultivar 'Koshihikari' by genetic manipulation of GABA shunt-related genes. In the study reported here, we grew these same novel rice lines in a field trial and administered the milled rice orally to rats. The yield parameters of the transgenic rice plants were almost unchanged compared to those of untransformed cv. 'Koshihikari' plants, while the rice grains of the transgenic plants contained a high GABA content (3.5 g GABA/kg brown rice; 0.75-0.85 GABA g/kg milled rice) in a greenhouse trial. Oral administration of a diet containing 2.5% GABA-fortified rice, with a daily intake for 8 weeks, had an approximately 20 mmHg anti-hypertensive effect in spontaneous hypertensive rats but not in normotensive Wistar-Kyoto rats. These results suggest that GABA-fortified rice may be applicable as a staple food to control or prevent hypertension.

  7. Genetic analysis of Resistance to Rice Bacterial blight in Uganda ...

    African Journals Online (AJOL)

    A full-diallel mating design involving three resistant and three susceptible rice cultivars was used to produce F1 and F2 progenies in a screen-house at the National Crop Resources Research Institute (NaCRRI), Namulonge in Uganda. The parents and F2 populations were challenged with the Xanthomonas oryzae ...

  8. Reducing arsenic accumulation in rice grain through iron oxide amendment

    Science.gov (United States)

    In this research, we investigated the accumulation of arsenic (As), selenium (Se), molybdenum (Mo), and cadmium (Cd) in rice grain under different soil conditions in standard straighthead-resistant and straighthead-susceptible cultivars, Zhe 733 and Cocodrie, respectively. Results demonstrated that,...

  9. SSR marker based DNA fingerprinting and diversity study in rice ...

    African Journals Online (AJOL)

    The genetic diversity and DNA fingerprinting of 15 elite rice genotypes using 30 SSR primers on chromosome numbers 7-12 was investigated. The results revealed that all the primers showed distinct polymorphism among the cultivars studied indicating the robust nature of microsatellites in revealing polymorphism. Cluster ...

  10. Socio-economic indicators influencing the adoption of hybrid ...

    African Journals Online (AJOL)

    The study observed the poor use of hybrid sorghum cultivars by subsistence farmers. The project sought to establish which, if any, socio-economic factors influence the adoption of hybrid sorghum cultivars by this sector of the farming community. The focus was on Makhuduthamaga Municipality in Sekhukhune District of ...

  11. Assessing hybrid sterility in Oryza glaberrima x O. sativa hybrid progenies by PCR marker analysis and crossing with wide compatibility varieties.

    Science.gov (United States)

    Heuer, Sigrid; Miézan, Kouamé M

    2003-09-01

    Interspecific crossing of the African indigenous rice Oryza glaberrima with Oryza sativa cultivars is hindered by crossing barriers causing 100% spikelet sterility in F(1) hybrids. Since hybrids are partially female fertile, fertility can be restored by back crossing (BC) to a recurrent male parent. Distinct genetic models on spikelet sterility have been developed predicting, e.g., the existence of a gamete eliminator and/or a pollen killer. Linkage of sterility to the waxy starch synthase gene and the chromogen gene C, both located on chromosome 6, have been demonstrated. We selected a segregating BC(2)F(3) population of semi-sterile O. glaberrima x O. sativa indica hybrid progenies for analyses with PCR markers located at the respective chromosome-6 region. These analyses revealed that semi-sterile plants were heterozygous for a marker (OSR25) located in the waxy promoter, whereas fertile progenies were homozygous for the O. glaberrima allele. Adjacent markers showed no linkage to spikelet sterility. Semi-sterility of hybrid progenies was maintained at least until the F(4) progeny generation, suggesting the existence of a pollen killer in this plant material. Monitoring of reproductive plant development showed that spikelet sterility was at least partially due to an arrest of pollen development at the microspore stage. In order to address the question whether genes responsible for F(1) sterility in intraspecific hybrids ( O. sativa indica x japonica) also cause spikelet sterility in interspecific hybrids, crossings with wide compatibility varieties (WCV) were performed. WCV accessions possess "neutral" S-loci ( S(n)) improving fertility in intraspecific hybrids. This experiment showed that the tested S(n)-loci had no fertility restoring effect in F(1) interspecific hybrids. Pollen development was completely arrested at the microspore stage and grains were never obtained after selfing. This suggests that distinct or additional S-loci are responsible for sterility

  12. Effects of storage and gamma irradiation on (japonica) waxy rice

    International Nuclear Information System (INIS)

    Sung, W.-C.; Hong, Mei-Chu; Chang, T.-S.

    2008-01-01

    Japonica cultivar, Taichung waxy 70 (TCW 70), was exposed to gamma radiation with doses ranging from 0 to 2.0 kGy. The effects of gamma irradiation on waxy rice pasting properties and the qualities of its food product, mochi, were compared to the effects of storage over 12 months. Doses ranging from 0.5 to 2 kGy can decrease the paste viscosity of waxy rice as those obtained after 6 months of storage. Radiation treatments were less effective to decrease the hardness of mochi than waxy rice samples stored over 6 months. It was shown the effects of gamma irradiation on shortening the japonica waxy rice aging time and improving the quality of rice products, like mochi, were not as good as the effects of storage

  13. Effects of storage and gamma irradiation on (japonica) waxy rice

    Energy Technology Data Exchange (ETDEWEB)

    Sung, W.-C. [Department of Hotel and Restaurant Management, Chia Nan University of Pharmacy and Science, 60 Erh-Jen Road, Sec. 1, Pao-An, Jen-Te Hsiang, Tainan 717, Taiwan (China)], E-mail: sungwilliam2001@yahoo.com.tw; Hong, Mei-Chu [TaiChung District Agricultural Research and Extension Station Council of Agriculture Executive Yuan, Taichung, Taiwan (China); Chang, T.-S. [Department of Biological Sciences and Technology, National University of Tainan, Tainan, Taiwan (China)

    2008-01-15

    Japonica cultivar, Taichung waxy 70 (TCW 70), was exposed to gamma radiation with doses ranging from 0 to 2.0 kGy. The effects of gamma irradiation on waxy rice pasting properties and the qualities of its food product, mochi, were compared to the effects of storage over 12 months. Doses ranging from 0.5 to 2 kGy can decrease the paste viscosity of waxy rice as those obtained after 6 months of storage. Radiation treatments were less effective to decrease the hardness of mochi than waxy rice samples stored over 6 months. It was shown the effects of gamma irradiation on shortening the japonica waxy rice aging time and improving the quality of rice products, like mochi, were not as good as the effects of storage.

  14. Adaptability and stability of carotenoids in maize cultivars

    Directory of Open Access Journals (Sweden)

    Sara de Almeida Rios

    2009-01-01

    Full Text Available The purpose of this study was to investigate the adaptability and stability of carotenoids in maize cultivars inthe 2004/2005 growing season. Total carotenoids (TC, total carotenoids with provitamin A activity (Pro VA (μg g-1 andgrain yield (kg ha-1 were quantified in 10 cultivars at five locations. The chemical analyses were conducted in a laboratoryof the EMBRAPA/CNPMS, in Sete Lagoas, Minas Gerais. The methodologies of Eberhart and Russell (1966, Lin and Binns(1988 and Rocha et al. (2005 were used to analyze adaptability and stability. In general, the linear regression modelproposed by Eberhart and Russell (1966 failed to fit the Pro VA contents in the evaluated cultivars satisfactorily. However,with regard to the TC levels, all different analysis methodologies of adaptability and stability rated hybrid BRS 2020 as anideal genotype with general adaptability.

  15. Modelagem da emissão de folhas em arroz cultivado e em arroz-vermelho Modeling leaf appearance in cultivated rice and red rice

    Directory of Open Access Journals (Sweden)

    Nereu Augusto Streck

    2008-05-01

    Full Text Available O objetivo deste trabalho foi simular o aparecimento de folhas em genótipos de arroz cultivados e em biótipos de arroz-vermelho por meio da adaptação do modelo de Wang e Engel, modificado por Streck et al. Dois experimentos foram conduzidos em Santa Maria, RS, em 2004/2005 e 2005/2006. Foram utilizadas as cultivares IRGA 417 e EEA 406, um híbrido e dois biótipos de arroz-vermelho. O modelo de aparecimento de folhas foi ajustado para os genótipos usando-se dados de estágio de Haun (HS, de cinco épocas de semeadura, em 2004/2005, e a avaliação do modelo foi feita com dados de HS medidos em três épocas de semeadura, em 2005/2006. Realizou-se também um experimento numérico utilizando-se dados de temperatura de 2003/2004 e de 2006/2007, e comparou-se o HS simulado dos genótipos cultivados em relação aos biótipos de arroz-vermelho. O modelo apresentou bom desempenho para simular o HS com raiz do quadrado médio do erro geralmente menor do que uma folha. A emissão de folhas na haste principal foi maior nos genótipos modernos - IRGA 417 e híbrido - do que no genótipo tradicional EEA 406. A emissão de folhas é diferente em distintos biótipos de arroz-vermelho.The objective of this work was to simulate leaf appearance in cultivated rice genotypes and in red rice biotypes, by adapting the Wang and Engel model modified by Streck et al. Two experiments were conducted in Santa Maria, Rio Grande do Sul State, Brazil, during 2004/2005 and 2005/2006 growing seasons. Cultivars IRGA 417 and EEA 406, one hybrid, and two red rice biotypes were used. The leaf appearance model was adjusted, using Haun Stage (HS data from five sowing dates of 2004/2005 growing season, and the model evaluation was performed using HS data from three sowing dates of 2005/2006 growing season. A numerical experiment was also carried out using temperature data occurred during 2003/2004 and 2006/2007 growing seasons, and simulated HS of the cultivated rice genotypes

  16. Genetic diversity assessed by microsatellite markers in sweet corn cultivars

    Directory of Open Access Journals (Sweden)

    Ana Daniela Lopes

    2015-12-01

    Full Text Available Information on genetic diversity is essential to the characterization and utilization of germplasm. The genetic diversity of twenty-two sweet corn cultivars (seventeen open-pollinated varieties, OPV, and five hybrids, H was investigated by applying simple sequence repeat markers. A total of 257 primers were tested, of which 160 were found to be usable in terms of high reproducibility for all the samples tested; 45 were polymorphic loci, of which 30 were used to assess the genetic diversity of sweet corn cultivars. We detected a total of 86 alleles using 30 microsatellite primers. The mean polymorphism was 82 %. The highest heterozygosity values (Ho = 0.20 were found in the PR030-Doce Flor da Serra and BR427 III OPVs, whereas the lowest values (0.14 were recorded in the MG161-Branco Doce and Doce Cubano OPVs. The polymorphism information content ranged from 0.19 (Umc2319 to 0.71 (Umc2205. The analysis of molecular variance revealed that most of the genetic variability was concentrated within the cultivars of sweet corn (75 %, with less variability between them (25 %. The consensus tree derived from the neighbor-joining (NJ algorithm using 1,000 bootstrapping replicates revealed seven genetically different groups. Nei’s diversity values varied between 0.103 (Doce do Hawai × CNPH-1 cultivars and 0.645 (Amarelo Doce × Lili cultivars, indicating a narrow genetic basis. The Lili hybrid was the most distant cultivar, as revealed by Principal Coordinates Analysis and the NJ tree. This study on genetic diversity will be useful for planning future studies on sweet corn genetic resources and can complement the breeding programs for this crop.

  17. Induction of male sterility in rice using chemical mutagens

    Energy Technology Data Exchange (ETDEWEB)

    Minocha, J L; Gupta, R K [Department of Genetics, Punjab Agricultural University, Ludhiana (India)

    1988-07-01

    Full text: To diversify the sources of cytoplasmic male sterility for hybrid seed production in rice (Oryza sativa L.) attempts were made to induce this character in a popular indica cultivar PR 106 through chemical mutagens. Seeds were treated with 0.4% ethidium bromide (EB) for 24 or 48h at 10 deg. C, with 0.4% ethyl methanesulphonate (EMS) for 24 or 48h at 10 deg. C for 16 hr at 20 deg. C or with 0.2% streptomycin sulphate (SM) for 24 or 48 hr at 10 deg. C. In M{sub 2} male sterile plants were detected in eleven different progenies, one from SM treatment and the remaining from EMS treatments. All the sterile plants had 100% non-stainable aborted pollen. Seed set upon open-pollination of the male sterile plants with the variety PR 106 ranged from 0.03 to 4.93 per cent whereas no seed formed in bagged panicles. In M{sub 3}, open-pollinated progenies of the male sterile plants and their fertile sibs were further studied. Two progenies segregated for male sterility, all others had only fertile plants. In one of the segregating progenies, five out of six and in the other nine out of fourteen plants were male sterile. The progenies of fertile sibs did not have any male sterile plant. The results indicate that sterility of cytoplasmic type has been induced by EMS. The parental variety PR 106 acts as the maintainer. (author)

  18. Induction of male sterility in rice using chemical mutagens

    International Nuclear Information System (INIS)

    Minocha, J.L.; Gupta, R.K.

    1988-01-01

    Full text: To diversify the sources of cytoplasmic male sterility for hybrid seed production in rice (Oryza sativa L.) attempts were made to induce this character in a popular indica cultivar PR 106 through chemical mutagens. Seeds were treated with 0.4% ethidium bromide (EB) for 24 or 48h at 10 deg. C, with 0.4% ethyl methanesulphonate (EMS) for 24 or 48h at 10 deg. C for 16 hr at 20 deg. C or with 0.2% streptomycin sulphate (SM) for 24 or 48 hr at 10 deg. C. In M 2 male sterile plants were detected in eleven different progenies, one from SM treatment and the remaining from EMS treatments. All the sterile plants had 100% non-stainable aborted pollen. Seed set upon open-pollination of the male sterile plants with the variety PR 106 ranged from 0.03 to 4.93 per cent whereas no seed formed in bagged panicles. In M 3 , open-pollinated progenies of the male sterile plants and their fertile sibs were further studied. Two progenies segregated for male sterility, all others had only fertile plants. In one of the segregating progenies, five out of six and in the other nine out of fourteen plants were male sterile. The progenies of fertile sibs did not have any male sterile plant. The results indicate that sterility of cytoplasmic type has been induced by EMS. The parental variety PR 106 acts as the maintainer. (author)

  19. Analysis on Factors Affecting Seedling Establishment in Rice

    Directory of Open Access Journals (Sweden)

    Ju LUO

    2007-03-01

    Full Text Available Elongations of coleoptile and mesocotyl are related directly to rice seedling establishment in soil and height of plant is related to lodging in rice production. Twelve typical rice cultivars with different lengths of coleoptile and mesocotyl (long, medium and short were selected by screening the lengths of coleoptile and mesocotyl in 1500 accessions. The seedling establishments of these typical cultivars were compared under the combinations of different sowing depths and flooding durations, and two semi-dwarf varieties (G140, Zhong 96–21 with good seedling establishments and optimum mesocotyl lengths were found. The length of mesocotyl was completely fitted negative binomial distribution and the length of coleoptile was nearly fitted lognormal distribution. Analysis of the relationships among mesocotyl, coleoptile, seeding depth, flooding duration, and their interactions to seedling establishment percentage showed that there existed significant relations among mesocotyl, coleoptile, mesocotyl × coleoptile, seeding depth, flooding duration and mesocotyl × sowing depth in the experiment for seedling establishment.

  20. Molecular evolution of shattering loci in U.S. weedy rice.

    Science.gov (United States)

    Thurber, Carrie S; Reagon, Michael; Gross, Briana L; Olsen, Kenneth M; Jia, Yulin; Caicedo, Ana L

    2010-08-01

    Cultivated rice fields worldwide are plagued with weedy rice, a conspecific weed of cultivated rice (Oryza sativa L.). The persistence of weedy rice has been attributed, in part, to its ability to shatter (disperse) seed prior to crop harvesting. In the United States, separately evolved weedy rice groups have been shown to share genomic identity with exotic domesticated cultivars. Here, we investigate the shattering phenotype in a collection of U.S. weedy rice accessions, as well as wild and cultivated relatives. We find that all U.S. weedy rice groups shatter seeds easily, despite multiple origins, and in contrast to a decrease in shattering ability seen in cultivated groups. We assessed allelic identity and diversity at the major shattering locus, sh4, in weedy rice; we find that all cultivated and weedy rice, regardless of population, share similar haplotypes at sh4, and all contain a single derived mutation associated with decreased seed shattering. Our data constitute the strongest evidence to date of an evolution of weeds from domesticated backgrounds. The combination of a shared cultivar sh4 allele and a highly shattering phenotype, suggests that U.S. weedy rice have re-acquired the shattering trait after divergence from their progenitors through alternative genetic mechanisms.

  1. Identifying molecular markers associated with stigma characteristics in rice

    Science.gov (United States)

    Stigma characteristics play essential roles in hybrid seed production of rice and marker-assisted breeding plays essential role because they are quantitatively inherited with single-flowered perfect spikelet. Ninety four accessions originated from 47 countries were selected from the USDA rice core c...

  2. Effects of genetically modified herbicide-tolerant (GMHT) rice on ...

    African Journals Online (AJOL)

    GREGORY

    2010-05-24

    May 24, 2010 ... To detect potential changes in properties of weed communities in fields of ... the hypothesis that the difference between the effect of GMHT rice Bar68-1 ... seed production, to raise purity of parents of hybrid rice, ... 3. 120. 20 × 20 cm. 2007. B. May 18. Jun 5. Aug 29 Aug 5, Sept 4. ..... part of agrobiodiversity.

  3. PHOTOPERIOD-INDUCED POLLEN ABORTION IN PGMS RICE

    African Journals Online (AJOL)

    user

    2013-11-20

    Nov 20, 2013 ... of the Hubei Photosensitive Genic Male-sterile Rice (Oryza sativa subsp. japonica). Acta Genetica Sinica 13(2):107-112. Virmani SS (1994). Heterosis and Hybrid Rice Breeding. Monographs on Theoretical and Applied Genetics. Springer-Verlag. Berlin. Heidelberg, Germany. 22:7(1). Virmani SS (1996).

  4. Rice Yellow Mottle Virus stress responsive genes from susceptible and tolerant rice genotypes

    Directory of Open Access Journals (Sweden)

    Siré Christelle

    2008-03-01

    Full Text Available Abstract Background The effects of viral infection involve concomitant plant gene variations and cellular changes. A simple system is required to assess the complexity of host responses to viral infection. The genome of the Rice yellow mottle virus (RYMV is a single-stranded RNA with a simple organisation. It is the most well-known monocotyledon virus model. Several studies on its biology, structure and phylogeography have provided a suitable background for further genetic studies. 12 rice chromosome sequences are now available and provide strong support for genomic studies, particularly physical mapping and gene identification. Results The present data, obtained through the cDNA-AFLP technique, demonstrate differential responses to RYMV of two different rice cultivars, i.e. susceptible IR64 (Oryza sativa indica, and partially resistant Azucena (O. s. japonica. This RNA profiling provides a new original dataset that will enable us to gain greater insight into the RYMV/rice interaction and the specificity of the host response. Using the SIM4 subroutine, we took the intron/exon structure of the gene into account and mapped 281 RYMV stress responsive (RSR transcripts on 12 rice chromosomes corresponding to 234 RSR genes. We also mapped previously identified deregulated proteins and genes involved in partial resistance and thus constructed the first global physical map of the RYMV/rice interaction. RSR transcripts on rice chromosomes 4 and 10 were found to be not randomly distributed. Seven genes were identified in the susceptible and partially resistant cultivars, and transcripts were colocalized for these seven genes in both cultivars. During virus infection, many concomitant plant gene expression changes may be associated with host changes caused by the infection process, general stress or defence responses. We noted that some genes (e.g. ABC transporters were regulated throughout the kinetics of infection and differentiated susceptible and

  5. (PGMS) rice

    African Journals Online (AJOL)

    user

    2011-04-18

    Apr 18, 2011 ... tics, led us to predict that pollen cell abortion in this type of rice when ... averages of natural day-light-lengths and temperatures were used. A natural long ... blocks were allowed to grow under natural growth conditions (which.

  6. Gene, protein, and network of male sterility in rice

    OpenAIRE

    Wang, Kun; Peng, Xiaojue; Ji, Yanxiao; Yang, Pingfang; Zhu, Yingguo; Li, Shaoqing

    2013-01-01

    Rice is one of the most important model crop plants whose heterosis has been well-exploited in commercial hybrid seed production via a variety of types of male-sterile lines. Hybrid rice cultivation area is steadily expanding around the world, especially in Southern Asia. Characterization of genes and proteins related to male sterility aims to understand how and why the male sterility occurs, and which proteins are the key players for microspores abortion. Recently, a series of genes and prot...

  7. Comparative study of endophytic and endophytic diazotrophic bacterial communities across rice landraces grown in the highlands of northern Thailand

    OpenAIRE

    Rangjaroen, C.; Rerkasem, B.; Teaumroong, N.; Sungthong, R.; Lumyong, S.

    2014-01-01

    Communities of bacterial endophytes within the rice landraces cultivated in the highlands of northern Thailand were studied using fingerprinting data of 16S rRNA and nifH genes profiling by polymerase chain reaction-denaturing gradient gel electrophoresis. The bacterial communities' richness, diversity index, evenness, and stability were varied depending on the plant tissues, stages of growth, and rice cultivars. These indices for the endophytic diazotrophic bacteria within the landrace rice ...

  8. Relative abundance of Delta(5)-sterols in plasma membrane lipids of root-tip cells correlates with aluminum tolerance of rice.

    Science.gov (United States)

    Khan, M Shahadat Hossain; Tawaraya, Keitarou; Sekimoto, Hiroshi; Koyama, Hiroyuki; Kobayashi, Yuriko; Murayama, Tetsuya; Chuba, Masaru; Kambayashi, Mihoko; Shiono, Yoshihito; Uemura, Matsuo; Ishikawa, Satoru; Wagatsuma, Tadao

    2009-01-01

    We investigated variations in aluminum (Al) tolerance among rice plants, using ancestor cultivars from the family line of the Al-tolerant and widely cultivated Japonica cultivar, Sasanishiki. The cultivar Rikuu-20 was Al sensitive, whereas a closely related cultivar that is a descendant of Rikuu-20, Rikuu-132, was Al tolerant. These two cultivars were compared to determine mechanisms underlying variations in Al tolerance. The sensitive cultivar Rikuu-20 showed increased permeability of the plasma membrane (PM) and greater Al uptake within 1 h of Al treatment. This could not be explained by organic acid release. Lipid composition of the PM differed between these cultivars, and may account for the difference in Al tolerance. The tolerant cultivar Rikuu-132 had a lower ratio of phospholipids to Delta(5)-sterols than the sensitive cultivar Rikuu-20, suggesting that the PM of Rikuu-132 is less negatively charged and less permeabilized than that of Rikuu-20. We used inhibitors of Delta(5)-sterol synthesis to alter the ratio of phospholipids to Delta(5)-sterols in both cultivars. These inhibitors reduced Al tolerance in Rikuu-132 and its Al-tolerant ancestor cultivars Kamenoo and Kyoku. In addition, Rikuu-132 showed a similar level of Al sensitivity when the ratio of phospholipids to Delta(5)-sterols was increased to match that of Rikuu-20 after treatment with uniconazole-P, an inhibitor of obtusifoliol-14alpha-demethylase. These results indicate that PM lipid composition is a factor underlying variations in Al tolerance among rice cultivars.

  9. Morphological evaluation of buffelgrass cultivar “Lucero INTA-PEMAN” in drought conditions

    OpenAIRE

    GRIFFA, S.; RIBOTTA, A; LUNA, C; BOLLATI, G; LÓPEZ COLOMBA, E.; TOMMASINO, E; CARLONI, E; QUIROGA, M.; GRUNBERG, K

    2011-01-01

    In searching for new cultivars that are better adapted to edapho-climatic constraints existing in northwestern Argentina, mainly drought and salinity stress, a hybrid of buffelgrass (Cenchrus ciliaris L.) named Lucero INTA PEMAN was obtained by controlled crosses at the Instituto de Fitopatología y Fisiología Vegetal, INTA. The objective was to morphologically evaluate and compare Cenchrus ciliaris cv Lucero with Texas-4464, Biloela and Molopo cultivars in Dean Funes (North of the Province of...

  10. Variation of photosynthetic tolerance of rice cultivars (Oryza sativa L ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-03-01

    Mar 1, 2010 ... (Oryza sativa L.) to chilling temperature in the light. Xia Li*, Kun Cao, Chao .... 2 mol) formed red-brown trimethine that can be detected quantitatively with spectrophoto- ..... ses through the generation of appropriate signals (H2O2) and the balance ..... was under weak light intensity (Murata, 1989). Light.

  11. Germination potential index of Sindh rice cultivars on biochemical ...

    African Journals Online (AJOL)

    use

    2011-12-14

    Dec 14, 2011 ... Alpha amylase activities were found to be directly correlated with germination percentage. Gradual increase in reducing sugars along with α-amylase activity was observed, while total ... seed vigor and alpha amylase activity along with germination period. .... strates for energy generation for fast and uniform.

  12. Dietary supplementation of germinated pigmented rice (Oryza sativa L. lowers dyslipidemia risk in ovariectomized Sprague–Dawley rats

    Directory of Open Access Journals (Sweden)

    Lara Marie Pangan Lo

    2016-03-01

    Full Text Available Background: In the recent years, cases of elderly women suffering from metabolic diseases such as dyslipidemias brought about by hormonal imbalance after menopause are continuously increasing. In this regard, a continuous and escalating demand to develop a more functional and highly nutritional food product as an adjunct supplement that can help alleviate these diseases is still being sought. Objective: This study investigated the effects of germinated blackish-purple rice cultivars Keunnunjami, Superjami, and reddish-brown cultivar Superhongmi in the lipid metabolism of ovariectomized Sprague–Dawley rats. Method: The animals were randomly divided into nine groups (n=5 and were supplemented with either non-germinated or germinated rice for 9 weeks. Then the plasma, liver, and fat samples were collected for the lipid metabolism effects analyses. Results: Animals fed with germinated rice cultivars had improved lipid profile levels relative to the groups supplemented with non-germinated rice cultivars. The germinated rice groups, Keununjami and Superjami in particular, showed a low total cholesterol levels, high levels of high-density lipoproteins-cholesterol, high fecal lipid output, low hepatic lipid values, and low hepatic adipocyte accumulation. There was also an increase in the rate of lipolysis and decrease in lipogenesis based on the lipid-regulating enzyme activity profiles obtained for the groups that fed on germinated rice. Also, results revealed that pigmented rice cultivars had superior effects in improving the lipid metabolism relative to the non-pigmented normal brown rice variety. Conclusion: Based on the results, this study suggests that germinated pigmented rice consumption can confer better lipid metabolism than ordinary white rice and constitutes as an effective functional food in alleviating the risk of having dyslipidemias like those suffering from menopausal co-morbidities.

  13. Isolation of a novel UVB-tolerant rice mutant obtained by exposure to carbon-ion beams.

    Science.gov (United States)

    Takano, Nao; Takahashi, Yuko; Yamamoto, Mitsuru; Teranishi, Mika; Yamaguchi, Hiroko; Sakamoto, Ayako N; Hase, Yoshihiro; Fujisawa, Hiroko; Wu, Jianzhong; Matsumoto, Takashi; Toki, Seiichi; Hidema, Jun

    2013-07-01

    UVB radiation suppresses photosynthesis and protein biosynthesis in plants, which in turn decreases growth and productivity. Here, an ultraviolet-B (UVB)-tolerant rice mutant, utr319 (UV Tolerant Rice 319), was isolated from a mutagenized population derived from 2500 M1 seeds (of the UVB-resistant cultivar 'Sasanishiki') that were exposed to carbon ions. The utr319 mutant was more tolerant to UVB than the wild type. Neither the levels of UVB-induced cyclobutane pyrimidine dimers (CPDs) or (6-4) pyrimidine-pyrimidone photodimers [(6-4) photoproducts], nor the repair of CPDs or (6-4) photoproducts, was altered in the utr319 mutant. Thus, the utr319 mutant may be impaired in the production of a previously unidentified factor that confers UVB tolerance. To identify the mutated region in the utr319 mutant, microarray-based comparative genomic hybridization analysis was performed. Two adjacent genes on chromosome 7, Os07g0264900 and Os07g0265100, were predicted to represent the mutant allele. Sequence analysis of the chromosome region in utr319 revealed a deletion of 45 419 bp. RNAi analysis indicated that Os07g0265100 is most likely the mutated gene. Database analysis indicated that the Os07g0265100 gene, UTR319, encodes a putative protein with unknown characteristics or function. In addition, the homologs of UTR319 are conserved only among land plants. Therefore, utr319 is a novel UVB-tolerant rice mutant and UTR319 may be crucial for the determination of UVB sensitivity in rice, although the function of UTR319 has not yet been determined.

  14. Isolation of a novel UVB-tolerant rice mutant obtained by exposure to carbon-ion beams

    International Nuclear Information System (INIS)

    Takano, Nao; Takahashi, Yuko; Yamamoto, Mitsuru; Teranishi, Mika; Yamaguchi, Hiroko; Sakamoto, Ayako N.; Hase, Yoshihiro; Fujisawa, Hiroko; Wu, Jianzhong; Matsumoto, Takashi; Toki, Seiichi; Hidema, Jun

    2013-01-01

    UVB radiation suppresses photosynthesis and protein biosynthesis in plants, which in turn decreases growth and productivity. Here, an ultraviolet-B (UVB)-tolerant rice mutant, utr319 (UVTolerantRice319), was isolated from a mutagenized population derived from 2500 M 1 seeds (of the UVB-resistant cultivar ‘Sasanishiki’) that were exposed to carbon ions. The utr319 mutant was more tolerant to UVB than the wild type. Neither the levels of UVB-induced cyclobutane pyrimidine dimers (CPDs) or (6-4) pyrimidine-pyrimidone photodimers [(6-4) photoproducts], nor the repair of CPDs or (6-4) photoproducts, was altered in the utr319 mutant. Thus, the utr319 mutant may be impaired in the production of a previously unidentified factor that confers UVB tolerance. To identify the mutated region in the utr319 mutant, microarray-based comparative genomic hybridization analysis was performed. Two adjacent genes on chromosome 7, Os07g0264900 and Os07g0265100, were predicted to represent the mutant allele. Sequence analysis of the chromosome region in utr319 revealed a deletion of 45 419 bp. RNAi analysis indicated that Os07g0265100 is most likely the mutated gene. Database analysis indicated that the Os07g0265100 gene, UTR319, encodes a putative protein with unknown characteristics or function. In addition, the homologs of UTR319 are conserved only among land plants. Therefore, utr319 is a novel UVB-tolerant rice mutant and UTR319 may be crucial for the determination of UVB sensitivity in rice, although the function of UTR319 has not yet been determined

  15. ELONGATED UPPERMOST INTERNODE Encodes a Cytochrome P450 Monooxygenase That Epoxidizes Gibberellins in a Novel Deactivation Reaction in RiceW⃞

    Science.gov (United States)

    Zhu, Yongyou; Nomura, Takahito; Xu, Yonghan; Zhang, Yingying; Peng, Yu; Mao, Bizeng; Hanada, Atsushi; Zhou, Haicheng; Wang, Renxiao; Li, Peijin; Zhu, Xudong; Mander, Lewis N.; Kamiya, Yuji; Yamaguchi, Shinjiro; He, Zuhua

    2006-01-01

    The recessive tall rice (Oryza sativa) mutant elongated uppermost internode (eui) is morphologically normal until its final internode elongates drastically at the heading stage. The stage-specific developmental effect of the eui mutation has been used in the breeding of hybrid rice to improve the performance of heading in male sterile cultivars. We found that the eui mutant accumulated exceptionally large amounts of biologically active gibberellins (GAs) in the uppermost internode. Map-based cloning revealed that the Eui gene encodes a previously uncharacterized cytochrome P450 monooxygenase, CYP714D1. Using heterologous expression in yeast, we found that EUI catalyzed 16α,17-epoxidation of non-13-hydroxylated GAs. Consistent with the tall and dwarfed phenotypes of the eui mutant and Eui-overexpressing transgenic plants, respectively, 16α,17-epoxidation reduced the biological activity of GA4 in rice, demonstrating that EUI functions as a GA-deactivating enzyme. Expression of Eui appeared tightly regulated during plant development, in agreement with the stage-specific eui phenotypes. These results indicate the existence of an unrecognized pathway for GA deactivation by EUI during the growth of wild-type internodes. The identification of Eui as a GA catabolism gene provides additional evidence that the GA metabolism pathway is a useful target for increasing the agronomic value of crops. PMID:16399803

  16. Influence of Climate Factors on Rice Yields in Cambodia

    Directory of Open Access Journals (Sweden)

    Dek Vimean Pheakdey

    2017-12-01

    Full Text Available Temperature and precipitation have been known as the key determinant factors to affect rice production in climate change. In this study, the relationship between climate variables and rice yields during 1993–2012 in Cambodia was analyzed and evaluated. The Ordinary Least Squares analysis was applied to examine the relationship of three climate variables (TCV including maximum temperature, minimum temperature and rainfall against seasonal rice yields. By this period, a remarkable increasing trend of annual temperature was observed whilst rainfall was not significantly changed. The TCV explains approximately 63% and 56% of the variability of rice yields in wet and dry seasons, respectively. It is found that in Cambodia, non-climate factors such as fertilizers, water, cultivars, and soil fertility cause 40% variation to rice yields, whereas the remaining 60% can be influenced by climate variability. The levels of temperature difference (LTD between maximum and minimum temperatures of the wet season (WS and dry season (DS were 7.0 and 8.6 oC, respectively. The lower value of LTD may cause the reduction of rice in WS (2.2 tons/ha as compared to that of DS (3.0 tons/ha. Rice yield has increased 50.5% and 33.8% in DS and WS, respectively, may due to the improvement of rice cultivation practices in Cambodia such as the better use of fertilizers, pest and weed control, and irrigation, and more effective rice cultivated protocol, as the increased trend of temperature may detrimentally affect rice yield. The breeding of heat and drought tolerance rice varieties and development of irrigation system are effective to reduce the negative influence from climate change to rice production in Cambodia.

  17. Evaluation of Rice Resistance to Southern Rice Black-Streaked Dwarf Virus and Rice Ragged Stunt Virus through Combined Field Tests, Quantitative Real-Time PCR, and Proteome Analysis.

    Science.gov (United States)

    Wang, Zhenchao; Yu, Lu; Jin, Linhong; Wang, Wenli; Zhao, Qi; Ran, Longlu; Li, Xiangyang; Chen, Zhuo; Guo, Rong; Wei, Yongtian; Yang, Zhongcheng; Liu, Enlong; Hu, Deyu; Song, Baoan

    2017-02-22

    Diseases caused by southern rice black-streaked dwarf virus (SRBSDV) and rice ragged stunt virus (RRSV) considerably decrease grain yield. Therefore, determining rice cultivars with high resistance to SRBSDV and RRSV is necessary. In this study, rice cultivars with high resistance to SRBSDV and RRSV were evaluated through field trials in Shidian and Mangshi county, Yunnan province, China. SYBR Green I-based quantitative real-time polymerase chain reaction (qRT-PCR) analysis was used to quantitatively detect virus gene expression levels in different rice varieties. The following parameters were applied to evaluate rice resistance: acre yield (A.Y.), incidence of infected plants (I.I.P.), virus load (V.L.), disease index (D.I.), and insect quantity (I.Q.) per 100 clusters. Zhongzheyou1 (Z1) and Liangyou2186 (L2186) were considered the most suitable varieties with integrated higher A.Y., lower I.I.P., V.L., D.I. and I.Q. In order to investigate the mechanism of rice resistance, comparative label-free shotgun liquid chromatography tandem-mass spectrometry (LC-MS/MS) proteomic approaches were applied to comprehensively describe the proteomics of rice varieties' SRBSDV tolerance. Systemic acquired resistance (SAR)-related proteins in Z1 and L2186 may result in the superior resistance of these varieties compared with Fengyouxiangzhan (FYXZ).

  18. Genome-wide DNA polymorphism in the indica rice varieties RGD-7S and Taifeng B as revealed by whole genome re-sequencing.

    Science.gov (United States)

    Fu, Chong-Yun; Liu, Wu-Ge; Liu, Di-Lin; Li, Ji-Hua; Zhu, Man-Shan; Liao, Yi-Long; Liu, Zhen-Rong; Zeng, Xue-Qin; Wang, Feng

    2016-03-01

    Next-generation sequencing technologies provide opportunities to further understand genetic variation, even within closely related cultivars. We performed whole genome resequencing of two elite indica rice varieties, RGD-7S and Taifeng B, whose F1 progeny showed hybrid weakness and hybrid vigor when grown in the early- and late-cropping seasons, respectively. Approximately 150 million 100-bp pair-end reads were generated, which covered ∼86% of the rice (Oryza sativa L. japonica 'Nipponbare') reference genome. A total of 2,758,740 polymorphic sites including 2,408,845 SNPs and 349,895 InDels were detected in RGD-7S and Taifeng B, respectively. Applying stringent parameters, we identified 961,791 SNPs and 46,640 InDels between RGD-7S and Taifeng B (RGD-7S/Taifeng B). The density of DNA polymorphisms was 256.8 SNPs and 12.5 InDels per 100 kb for RGD-7S/Taifeng B. Copy number variations (CNVs) were also investigated. In RGD-7S, 1989 of 2727 CNVs were overlapped in 218 genes, and 1231 of 2010 CNVs were annotated in 175 genes in Taifeng B. In addition, we verified a subset of InDels in the interval of hybrid weakness genes, Hw3 and Hw4, and obtained some polymorphic InDel markers, which will provide a sound foundation for cloning hybrid weakness genes. Analysis of genomic variations will also contribute to understanding the genetic basis of hybrid weakness and heterosis.

  19. Lily Cultivars Have Allelopathic Potential in Controlling Orobanche aegyptiaca Persoon.

    Science.gov (United States)

    Chai, Min; Zhu, Xiaopei; Cui, Hongxia; Jiang, Chuangdao; Zhang, Jinzheng; Shi, Lei

    2015-01-01

    As a devastating holoparasitic weed, Orobanche aegyptiaca Persoon. (Egyptian broomrape) causes serious damage to agricultural production and threatens economic development, which has raised widespread concern. The present study was conducted to determine whether lilies have the potential to be used as 'trap crops' for controlling O. aegyptiaca Persoon. In the experiments, the ability of three popular lily cultivars (Lilium Oriental hybrids 'Sorbonne', Lilium LA (Longiflorum hybrids x Asiatic hybrids) hybrids 'Ceb Dazzle', and Lilium Longiflorum hybrids (L. formosanum x L. longiflorum) 'L. formolongo') to induce O. aegyptiaca Persoon. seed germination was assessed. Parts of the three lily cultivars, including the rhizosphere soil and underground and above-ground organs, all induced "suicidal germination" of parasitic O. aegyptiaca Persoon. seed at four growth stages. Specifically, Sorbonne and Ceb Dazzle behaved with similar allelopathy, and the bulb, scale leaf and aerial stem exhibited stronger allelopathic effects on O. aegyptiaca Pers. germination compared to other organs. Aqueous L. formolongo leaf extracts may contain more stable, effective stimulants given that they induced the highest germination rate at 76.7% even though the extracts were serially diluted. We speculate that these organs may be advantageous in further isolating and purifying economical active substances that can be substitutes for GR24. These results indicate that lilies have the potential to be used as a trap crops or can be processed into green herbicide formulations that can be applied in agriculture production to rapidly deplete the seed bank of O. aegyptiaca Persoon. parasitic weeds in soil.

  20. Lily Cultivars Have Allelopathic Potential in Controlling Orobanche aegyptiaca Persoon.

    Directory of Open Access Journals (Sweden)

    Min Chai

    Full Text Available As a devastating holoparasitic weed, Orobanche aegyptiaca Persoon. (Egyptian broomrape causes serious damage to agricultural production and threatens economic development, which has raised widespread concern. The present study was conducted to determine whether lilies have the potential to be used as 'trap crops' for controlling O. aegyptiaca Persoon. In the experiments, the ability of three popular lily cultivars (Lilium Oriental hybrids 'Sorbonne', Lilium LA (Longiflorum hybrids x Asiatic hybrids hybrids 'Ceb Dazzle', and Lilium Longiflorum hybrids (L. formosanum x L. longiflorum 'L. formolongo' to induce O. aegyptiaca Persoon. seed germination was assessed. Parts of the three lily cultivars, including the rhizosphere soil and underground and above-ground organs, all induced "suicidal germination" of parasitic O. aegyptiaca Persoon. seed at four growth stages. Specifically, Sorbonne and Ceb Dazzle behaved with similar allelopathy, and the bulb, scale leaf and aerial stem exhibited stronger allelopathic effects on O. aegyptiaca Pers. germination compared to other organs. Aqueous L. formolongo leaf extracts may contain more stable, effective stimulants given that they induced the highest germination rate at 76.7% even though the extracts were serially diluted. We speculate that these organs may be advantageous in further isolating and purifying economical active substances that can be substitutes for GR24. These results indicate that lilies have the potential to be used as a trap crops or can be processed into green herbicide formulations that can be applied in agriculture production to rapidly deplete the seed bank of O. aegyptiaca Persoon. parasitic weeds in soil.

  1. Arsenic biotransformation and volatilization in transgenic rice

    Science.gov (United States)

    Meng, Xiang-Yan; Qin, Jie; Wang, Li-Hong; Duan, Gui-Lan; Sun, Guo-Xin; Wu, Hui-Lan; Chu, Cheng-Cai; Ling, Hong-Qing; Rosen, Barry P.; Zhu, Yong-Guan

    2011-01-01

    Summary Biotransformation of arsenic includes oxidation, reduction, methylation and conversion to more complex organic arsenicals. Members of the class of arsenite [As(III)] S-adenosylmethyltransferase enzymes catalyze As(III) methylation to a variety of mono-, di- and trimethylated species, some of which are less toxic than As(III) itself. However, no methyltransferase gene has been identified in plants. Here, an arsM gene from the soil bacterium Rhodopseudomonas palustris was expressed in Japonica rice (Oryza sativa L.) cultivar Nipponbare, and the transgenic rice produced methylated arsenic species, which were measured by inductively coupled plasma mass spectrometry (ICP-MS) and high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). Both monomethylarsenate [MAs(V)] and dimethylarsenate [DMAs(V)] were detected in the root and shoot of transgenic rice. After 12-d exposure to As(III), the transgenic rice gave off 10-fold more volatile arsenicals. The present study demonstrates that expression of an arsM gene in rice induces arsenic methylation and volatilization, providing a potential stratagem for phytoremediation theoretically. PMID:21517874

  2. BRS Progresso – Rye cultivar

    Directory of Open Access Journals (Sweden)

    Alfredo do Nascimento Junior

    2014-10-01

    Full Text Available The rye cultivar BRS Progresso, developed by the Brazilian Agricultural Research Corporation (Embrapa, is the result of a synthetic cross of 18 open-pollinated, self-incompatible lines, resistant to stem rust.

  3. A preliminary study on identification of Thai rice samples by INAA and statistical analysis

    Science.gov (United States)

    Kongsri, S.; Kukusamude, C.

    2017-09-01

    This study aims to investigate the elemental compositions in 93 Thai rice samples using instrumental neutron activation analysis (INAA) and to identify rice according to their types and rice cultivars using statistical analysis. As, Mg, Cl, Al, Br, Mn, K, Rb and Zn in Thai jasmine rice and Sung Yod rice samples were successfully determined by INAA. The accuracy and precision of the INAA method were verified by SRM 1568a Rice Flour. All elements were found to be in a good agreement with the certified values. The precisions in term of %RSD were lower than 7%. The LODs were obtained in range of 0.01 to 29 mg kg-1. The concentration of 9 elements distributed in Thai rice samples was evaluated and used as chemical indicators to identify the type of rice samples. The result found that Mg, Cl, As, Br, Mn, K, Rb, and Zn concentrations in Thai jasmine rice samples are significantly different but there was no evidence that Al is significantly different from concentration in Sung Yod rice samples at 95% confidence interval. Our results may provide preliminary information for discrimination of rice samples and may be useful database of Thai rice.

  4. Possible contribution of induced mutations on breaking the rice yield barrier

    International Nuclear Information System (INIS)

    Sobrizal and Moch Ismachin

    2006-01-01

    At The World Rice Research Conference in Tsukuba, Japan, on 4 — 7 November 2004, there was an active discussion on how to increase the world rice yield production. Breeders agreed that after IR8, the yield potential of rice varieties could not increase drastically. From the breeding point of view, there were two approaches that already started in three to one decade ago, but it is still unfinished yet. These two approaches were to do breeding for hybrid rice varieties or breeding for new plant idiotype varieties. The idea to produce hybrid rice was stimulated by the success of hybrid corn, onion, and sorghum on commercial basis. Among the countries that are working for producing hybrid rice varieties, China was the leading one. China produced hybrid rice varieties and which are planted already in very large area. This success influenced other countries to do the same, including Indonesia. Now Indonesia has already released 11 hybrid rice varieties. Knowing so many characters that are already present in the rice collection, the idea to produce new plant idiotype appears. It seems not difficult to unite selected characters to become a new plant idiotype. In fact, however, up to now there are still a lot of obstacles that make those two approaches could not reach the real goal. This paper will discuss the possible contribution of induced mutations toward the success of these two approaches. (author)

  5. Current Insights into Research on Rice stripe virus

    Directory of Open Access Journals (Sweden)

    Won Kyong Cho

    2013-09-01

    Full Text Available Rice stripe virus (RSV is one of the most destructive viruses of rice, and greatly reduces rice production in China, Japan, and Korea, where mostly japonica cultivars of rice are grown. RSV is transmitted by the small brown plant-hopper (SBPH in a persistent and circulative-propagative manner. Several methods have been developed for detection of RSV, which is composed of four single-stranded RNAs that encode seven proteins. Genome sequence data and comparative phylogenetic analysis have been used to identify the origin and diversity of RSV isolates. Several rice varieties resistant to RSV have been selected and QTL analysis and fine mapping have been intensively performed to map RSV resistance loci or genes. RSV genes have been used to generate several genetically modified transgenic rice plants with RSV resistance. Recently, genome-wide transcriptome analyses and deep sequencing have been used to identify mRNAs and small RNAs involved in RSV infection; several rice host factors that interact with RSV proteins have also been identified. In this article, we review the current statues of RSV research and propose integrated approaches for the study of interactions among RSV, rice, and the SBPH.

  6. Modeling the leaf angle dynamics in rice plant.

    Directory of Open Access Journals (Sweden)

    Yonghui Zhang

    Full Text Available The leaf angle between stem and sheath (SSA is an important rice morphological trait. The objective of this study was to develop and validate a dynamic SSA model under different nitrogen (N rates for selected rice cultivars. The time-course data of SSA were collected in three years, and a dynamic SSA model was developed for different main stem leaf ranks under different N rates for two selected rice cultivars. SSA increased with tiller age. The SSA of the same leaf rank increased with increase in N rate. The maximum SSA increased with leaf rank from the first to the third leaf, then decreased from the third to the final leaf. The relationship between the maximum SSA and leaf rank on main stem could be described with a linear piecewise function. The change of SSA with thermal time (TT was described by a logistic equation. A variety parameter (the maximum SSA of the 3rd leaf on main stem and a nitrogen factor were introduced to quantify the effect of cultivar and N rate on SSA. The model was validated against data collected from both pot and field experiments. The relative root mean square error (RRMSE was 11.56% and 14.05%, respectively. The resulting models could be used for virtual rice plant modeling and plant-type design.

  7. Physicochemical and sensory profile of rice bran roasted in microwave

    Directory of Open Access Journals (Sweden)

    Marina Costa Garcia

    2012-12-01

    Full Text Available The purpose of this study was to evaluate the physical, chemical, and sensory changes in bran from three rice cultivars according to microwave roasting time. This study analyzed three rice cultivars, BRS Sertaneja (S, BRS Primavera (P, and IRGA 417 (I determining the color parameters (L*, a*, and b * at 6, 9, 12, 15, and 18 minutes of roasting time. After applying the difference from control test, the rice brans with different characteristics aroma and flavor were selected: S and P roasted for 9 and 15 minutes and IRGA 417 roasted for 9, 12, and 15 minutes. These samples were characterized by Free-Choice Profile descriptive sensory analysis, and their chemical composition was also determined. The longer the roasting process, the higher the roasted flavor intensity and aroma. The IRG 417 cultivar roasted for 12 minutes showed a sweeter flavor and aroma. After roasting, the brans remained rich in protein and lipid and presented higher fiber content and lower reducing sugar and phytic acid content. Microwave roasting for 12 minutes can be a viable option for improving the sensory functional and nutritional characteristics of the rice bran considering its use in food products.

  8. Selectable antibiotic resistance marker gene-free transgenic rice harbouring the garlic leaf lectin gene exhibits resistance to sap-sucking planthoppers.

    Science.gov (United States)

    Sengupta, Subhadipa; Chakraborti, Dipankar; Mondal, Hossain A; Das, Sampa

    2010-03-01

    Rice, the major food crop of world is severely affected by homopteran sucking pests. We introduced coding sequence of Allium sativum leaf agglutinin, ASAL, in rice cultivar IR64 to develop sustainable resistance against sap-sucking planthoppers as well as eliminated the selectable antibiotic-resistant marker gene hygromycin phosphotransferase (hpt) exploiting cre/lox site-specific recombination system. An expression vector was constructed containing the coding sequence of ASAL, a potent controlling agent against green leafhoppers (GLH, Nephotettix virescens) and brown planthopper (BPH, Nilaparvata lugens). The selectable marker (hpt) gene cassette was cloned within two lox sites of the same vector. Alongside, another vector was developed with chimeric cre recombinase gene cassette. Reciprocal crosses were performed between three single-copy T(0) plants with ASAL- lox-hpt-lox T-DNA and three single-copy T(0) plants with cre-bar T-DNA. Marker gene excisions were detected in T(1) hybrids through hygromycin sensitivity assay. Molecular analysis of T(1) plants exhibited 27.4% recombination efficiency. T(2) progenies of L03C04(1) hybrid parent showed 25% cre negative ASAL-expressing plants. Northern blot, western blot and ELISA showed significant level of ASAL expression in five marker-free T(2) progeny plants. In planta bioassay of GLH and BPH performed on these T(2) progenies exhibited radical reduction in survivability and fecundity compared with the untransformed control plants.

  9. CRISPR/Cas9-Mediated Gene Editing in Rice (Oryza sativa L. japonica cv. Katy) for Stable Resistance against Blast Fungus (Magnaporthe oryzae)

    Science.gov (United States)

    Rice blast is a recurring and devastating disease in the USA and worldwide. In the USA, the blast-resistance (R) genes found in a tropical japonica cultivar, Katy, reduce blast damages from 1990 to present. The cultivar is still used as a principal donor of blast R genes in developing numerous elit...

  10. Photoperiodic control of floral initiation in rice plant, 4: Promotive effect of far-red radiation given at the end of day

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, K. [Mie Univ., Tsu (Japan)

    1987-12-15

    Using a strongly photoperiod-sensitive cultivar of rice, Oryza sativa L., ev. Norin 18, though several cultivars with weak sensitivity to photoperiod were added in some trials, we have investigated on the effect of FR radiation at the close of the daily photoperiod on the flowering response.

  11. Mutant heterosis in rice

    International Nuclear Information System (INIS)

    1987-01-01

    In the variety TKM6 a high yielding semidwarf mutant has been induced. This TKM6 mutant was used in test crosses with a number of other varieties and mutants to examine the extent of heterosis of dwarfs in rice and to select superior crosses. An excerpt of the published data is given. It appears from the backcross of the mutant with its original variety, that an increase in number of productive tillers occurs in the hybrid, leading to a striking grain yield increase, while the semi-dwarf culm length (the main mutant character) reverts to the normal phenotype. In the cross with IR8 on the other hand, there is only a minimal increase in tiller number but a substantial increase in TGW leading to more than 30% yield increase over the better parent

  12. ADSORPSI ION SIANIDA DALAM LARUTAN MENGGUNAKAN ADSORBEN HIBRIDA AMINOPROPIL SILIKA GEL DARI SEKAM PADI TERIMPREGNASI ALUMINIUM (Adsorption of Cyanide Ions in Solution Using a Hybrid Adsorbent Aminopropyl Silica Gel from Rice Husks of Impregnated With

    Directory of Open Access Journals (Sweden)

    Amaria Amaria

    2012-03-01

    aminopropil silica gel from rice husk that has been impregnated with aluminum (APSG-Al and silica gel impregnated with aluminum (SG-Al of rice husk silica gel as the material for the adsorption of cyanide ions in solution. The interaction between the adsorbent with cyanide ions in solution performed in a batch system. The parameters examined in this study were the influence of medium pH, the effect of interaction time and the effect of initial concentration of cyanide ion adsorption ability of adsorbent hybrid amino silica gel impregnated with aluminum. Quantitative Analysis of cyanide ions left in the filtrate was tested by means of ion selective electrode. The effect of interaction time data were analyzed with kinetic model, the data of the influence of cyanide ion concentration was analyzed by Langmuir adsorption isotherm model and Freundlich. The results showed that the infrared spectroscopic identification results show APSG-Al adsorbent has silanol groups (Si-OH, siloxil (Si-O-Si, primary amine group, NH2. The result of XRD analysis of the price of 2θ at 65.51 indicates that the aluminum impregnated with the silica in the form of alumina Al2O3. The result of adsorption of cyanide by the hybrid silica gel impregnated with aluminum aminopropil (APSG-Al showed maximum adsorption occurred at pH 5 was 67.62%, silica gel impregnated with aluminum was 51,11%. Study the kinetics of the effect of interaction time showed that the adsorbent APSG-Al and SG-Al-Al has the adsorption rate constant k1 is 2.7, 10-3and 1.9,10-3 min-1, respectively. Adsorption equilibrium data showed that the adsorbent APSG-Al and SG-Al tend to follow the adsorption isotherm model Freundlich.

  13. BACTÉRIAS DIAZOTRÓFICAS E ADUBAÇÃO NITROGENADA EM CULTIVARES DE ARROZ

    Directory of Open Access Journals (Sweden)

    SALOMÃO LIMA GUIMARÃES

    2010-01-01

    Full Text Available The purpose of this study was to evaluate the effect of diazotrophic bacteria inoculation and nitrogen fertilization on grain yield and nitrogen accumulation in rice plants. We used seeds of rice cultivars IR42 and IAC4440, which were inoculated with peat containing the strains ZAE94 (BR 11417 - Herbaspirillum seropedicae and M130 (BR 11340 - Burkholderia sp.. We used the first 20 cm of an Albaqualf Ecological Series. The experiment was conducted in a completely randomized design with four replications and four plants per pot. We applied three levels of nitrogen (0, 50 and 100 kg N ha--1 and evaluated the parameters of shoot dry weight, nitrogen accumulation in shoots and grains, in addition to grain yield and the quantification of population of diazotrophic plants. Positive effects of inoculation were observed in both cultivars studied in all parameters evaluated, mainly in the accumulation of nitrogen in plants and grains.

  14. Potential Impact of Biotechnology on Adaption of Agriculture to Climate Change: The Case of Drought Tolerant Rice Breeding in Asia

    Directory of Open Access Journals (Sweden)

    R. Chandra Babu

    2011-09-01

    Full Text Available In Asia and Africa the poor tend to live in marginal environments where droughts and floods are frequent. Global warming is expected to increase the frequency of these weather-induced perturbations of crop production. Drought tolerance (DT has been one of the most difficult traits to improve in genetic crop improvement programs worldwide. Biotechnology provides breeders with a number of new tools that may help to develop more drought tolerant varieties such as marker assisted selection (MAS, molecular breeding (MB, and transgenic plants. This paper assesses some preliminary evidence on the potential impact of biotechnology using data from surveys of the initial DT cultivars developed through one of the main programs in Asia that has been funding DT rice breeding since 1998—The Rockefeller Foundation’s Resilient Crops for Water-Limited Environments program in China, India, and Thailand. Yield increases of DT rice varieties are 5 to 10 percent better than conventional varieties or currently grown commercial varieties than it has been in years. So far we only have experiment station evidence that DT varieties yielded better than conventional or improved varieties during moderate drought years (the one drought year during our study period in South India gave inconclusive results and in severe drought both the DT and the conventional varieties were either not planted or, if planted, did not yield. We find that the governments could help overcome some of the constraints to the spread of DT cultivars by increasing government funding of DT research programs that take advantage of new biotech techniques and new knowledge from genomics. Secondly, public scientists can make breeding lines with DT traits and molecular markers more easily available to the private seed firms so that they can incorporate DT traits into their commercial hybrids particularly for poor areas. Third, governments can subsidize private sector production of DT seed or provide more

  15. Fine mapping and introgressing qFIS1-2, a major QTL for kernel fissure resistance in rice (Oryza sativa L.)

    Science.gov (United States)

    Rice (Oryza sativa L.) kernel fissuring increases breakage during milling and decreases the value of processed rice. This study employed molecular gene tagging methods to fine-map a fissure resistance (FR) locus in ‘Cybonnet’, a semidwarf tropical japonica cultivar, as well as transfer this trait to...

  16. Manganese-induced regulations in growth, yield formation, quality characters, rice aroma and enzyme involved in 2-acetyl-1-pyrroline biosynthesis in fragrant rice.

    Science.gov (United States)

    Li, Meijuan; Ashraf, Umair; Tian, Hua; Mo, Zhaowen; Pan, Shenggang; Anjum, Shakeel Ahmad; Duan, Meiyang; Tang, Xiangru

    2016-06-01

    Micro-nutrient application is essential for normal plant growth while a little is known about manganese (Mn)-induced regulations in morpho-physiological attributes, aroma formation and enzyme involved in 2-acetyl-1-pyrroline (2-AP) biosynthesis in aromatic rice. Present study aimed to examine the influence of four levels of Mn i.e., Mn1 (100 mg MnSO4 pot(-1)), Mn2 (150 mg MnSO4 pot(-1)), Mn3 (200 mg MnSO4 pot(-1)), and Mn4 (250 mg MnSO4 pot(-1)) on the growth, yield formation, quality characters, rice aroma and enzyme involved in 2-acetyl-1-pyrroline biosynthesis in two fragrant rice cultivars i.e., Meixiangzhan and Nongxiang 18. Pots without Mn application were served as control (Ck). Each pot contained 15 kg of soil. Effects on agronomic characters, quality attributes, 2-AP contents and enzymes involved in 2-AP biosynthesis have been studied in early and late season rice. Results depicted that Mn improved rice growth, yield and related characters, and some quality attributes significantly. It further up-regulated proline, pyrroline-5-carboxylic acid (P5C) (precursors of 2-AP), soluble proteins and activities of proline dehydrogenase (ProDH), Δ(1) pyrroline-5-carboxylic acid synthetase (P5CS) ornithine aminotransferase (OAT) that led to enhanced 2-AP production in rice grains. Moreover, higher Mn levels resulted in increased grain Mn contents in both rice cultivars. Along with growth and yield improvement, Mn application significantly improved rice aromatic contents. Overall, Nongxiang 18 accumulated more 2-AP contents than Meixiangzhan in both seasons under Mn application. This study further explored the importance of Mn in rice aroma formation and signifies that micro-nutrients can play significant roles in rice aroma synthesis; however, intensive studies at molecular levels are still needed to understand the exact mechanisms of Mn to improve rice aroma formation. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  17. Lead (Pb) Toxicity; Physio-Biochemical Mechanisms, Grain Yield, Quality, and Pb Distribution Proportions in Scented Rice.

    Science.gov (United States)

    Ashraf, Umair; Kanu, Adam S; Deng, Quanquan; Mo, Zhaowen; Pan, Shenggang; Tian, Hua; Tang, Xiangru

    2017-01-01

    Lead (Pb) caused interruptions with normal plant metabolism, crop yield losses and quality issues are of great concern. This study assessed the physio-biochemical responses, yield and grain quality traits and Pb distribution proportions in three different fragrant rice cultivars i.e., Meixiangzhan-2, Xinagyaxiangzhan and Basmati-385. Plants were exposed to 400, 800, and 1,200 ppm of Pb while pots without Pb were taken as control (0 ppm). Our results showed that Pb toxicity significantly ( P production of hydrogen peroxide (H 2 O 2 ), malanodialdehyde (MDA) and leaves leachates; while such effects were more apparent in Xinagyaxiangzhan than other two rice cultivars. Pb stress differentially affected the production protein, proline and soluble sugars; however the production rates were higher at heading stage (HS) than maturity stage (MS). Furthermore, Pb stress altered superoxide dismutase (SOD), peroxidases (POD), catalases (CAT) and ascorbate peroxidases (APX) activities and glutathione (GSH) and oxidized glutathione (GSSG) production in all rice cultivars at both HS and MS. All Pb levels reduced the yield and yield components of all rice cultivars; nonetheless such reductions were observed highest in Xinagyaxiangzhan (69.12%) than Meixiangzhan-2 (58.05%) and Basmati-385 (46.27%) and resulted in grain quality deterioration. Significant and positive correlations among rice yields with productive tillers/pot and grains per panicle while negative with sterility percentage were also observed. In addition, all rice cultivars readily taken up the Pb contents from soil to roots and transported upward in different proportions with maximum in roots followed by stemss, leaves, ears and grains. Higher proportions of Pb contents in above ground plant parts in Xinagyaxiangzhan possibly lead to maximum losses in this cultivar than other two cultivars; while less damage in Basmati-385 might be related to strong anti-oxidative defense system and lower proportions of Pb contents in

  18. Unraveling the genetic structure of Brazilian commercial sugarcane cultivars through microsatellite markers.

    Science.gov (United States)

    Manechini, João Ricardo Vieira; da Costa, Juliana Borges; Pereira, Bruna Turcatto; Carlini-Garcia, Luciana Aparecida; Xavier, Mauro Alexandre; Landell, Marcos Guimarães de Andrade; Pinto, Luciana Rossini

    2018-01-01

    The Brazilian sugarcane industry plays an important role in the worldwide supply of sugar and ethanol. Investigation into the genetic structure of current commercial cultivars and comparisons to the main ancestor species allow sugarcane breeding programs to better manage crosses and germplasm banks as well as to promote its rational use. In the present study, the genetic structure of a group of Brazilian cultivars currently grown by commercial producers was assessed through microsatellite markers and contrasted with a group of basic germplasm mainly composed of Saccharum officinarum and S. spontaneum accessions. A total of 285 alleles was obtained by a set of 12 SSRs primer pairs that taken together were able to efficiently distinguish and capture the genetic variability of sugarcane commercial cultivars and basic germplasm accessions allowing its application in a fast and cost-effective way for routine cultivar identification and management of sugarcane germplasm banks. Allelic distribution revealed that 97.6% of the cultivar alleles were found in the basic germplasm while 42% of the basic germplasm alleles were absent in cultivars. Of the absent alleles, 3% was exclusive to S. officinarum, 33% to S. spontaneum and 19% to other species/exotic hybrids. We found strong genetic differentiation between the Brazilian commercial cultivars and the two main species (S. officinarum: [Formula: see text] = 0.211 and S. spontaneum: [Formula: see text] = 0.216, Pcommercial cultivars. Average dissimilarity within cultivars was 1.2 and 1.4 times lower than that within S. officinarum and S. spontaneum. Genetic divergence found between cultivars and S. spontaneum accessions has practical applications for energy cane breeding programs as the choice of more divergent parents will maximize the frequency of transgressive individuals in the progeny.

  19. Study on homologous series of induced early mutants in Indica rice Ⅱ. the relationship between the homologous series of early mutants induced and the ecotype in Indica rice

    International Nuclear Information System (INIS)

    Chen Xiulan; Yang Hefeng; He Zhentian; Han Yuepeng; Liu Xueyu

    2001-01-01

    The induced mutation in light sensitivity of the Indica rice leads to induction of the homologous series of early mutants along with the variation of ecological character and the ecoclimate. The induction of mutants was closely related to the ecotype of Indica rice, the homologous series of early mutants in different level were derived from the different ecotype of the Indica rice, otherwise, the similar homologous series of early mutants were derived from the same ecotypic variety. The induction of the early ecotypic variety derived from the homologous series of early mutants provides the basis and possibility for accelerating the development of the new cultivars. (authors)

  20. Assessment of genetic variability in rice (oryza sativa l.) germplasm from Pakistan using rapd markers

    International Nuclear Information System (INIS)

    Pervaiz, Z.H.; Rabbani, M.A.; Shinwar, Z.K.; Masood, M.S.; Malik, S.A.

    2010-01-01

    Information on genetic diversity and relationships among rice genotypes from Pakistan is currently very limited. Molecular marker analysis can truly be beneficial in analyzing the diversity of rice germplasm providing useful information to broaden the genetic base of modern rice cultivars. The objective of this study was to evaluate the genetic polymorphism of 75 rice accessions and improved cultivars using random amplified polymorphic DNA (RAPD) technique. Twenty-eight decamer-primers generated a total of 145 RAPD fragments, of which 116 (80%) were polymorphic. The number of amplification products produced by each primer varied from 3 to 9 with an average of 5.2 alleles primer-1. The size of amplified fragments ranged from 250 to 4000bp. A dendrogram was generated from minimal variance algorithm using Ward method. All the 75 genotypes were grouped into two main groups corresponding to aromatic and non-aromatic types of indica rice. Clustering of accessions did not show any significant pattern of association between the RAPD fingerprints and collection sites. This type of analysis grouping different rice accessions in relation to fragrance, a major rice quality determinant, and varietal group is extremely useful to develop a core collection and gene bank management. Further more, the information revealed by the RAPDs regarding genetic variation is helpful to the plant breeder in selecting diverse parents and for future orientation of rice breeding program. (author)

  1. EFFECT OF NITROGEN-FIXING BACTERIA ON GRAIN YIELD AND DEVELOPMENT OF FLOODED IRRIGATED RICE

    Directory of Open Access Journals (Sweden)

    AMAURI NELSON BEUTLER

    2016-01-01

    Full Text Available This study aimed at evaluating the effect of Azospirillum brasilense , a nitrogen - fixing bacterium, on flooded irrigated rice yield. Evaluations were carried out in a shaded nursery, with seedlings grown on an Alfisol. Were performed two sets of experiments. In the first, were carri