Diversity of Global Rice Markets and the Science Required for Consumer-Targeted Rice Breeding

Science.gov (United States)

Calingacion, Mariafe; Laborte, Alice; Nelson, Andrew; Resurreccion, Adoracion; Concepcion, Jeanaflor Crystal; Daygon, Venea Dara; Mumm, Roland; Reinke, Russell; Dipti, Sharifa; Bassinello, Priscila Zaczuk; Manful, John; Sophany, Sakhan; Lara, Karla Cordero; Bao, Jinsong; Xie, Lihong; Loaiza, Katerine; El-hissewy, Ahmad; Gayin, Joseph; Sharma, Neerja; Rajeswari, Sivakami; Manonmani, Swaminathan; Rani, N. Shobha; Kota, Suneetha; Indrasari, Siti Dewi; Habibi, Fatemeh; Hosseini, Maryam; Tavasoli, Fatemeh; Suzuki, Keitaro; Umemoto, Takayuki; Boualaphanh, Chanthkone; Lee, Huei Hong; Hung, Yiu Pang; Ramli, Asfaliza; Aung, Pa Pa; Ahmad, Rauf; Wattoo, Javed Iqbal; Bandonill, Evelyn; Romero, Marissa; Brites, Carla Moita; Hafeel, Roshni; Lur, Huu-Sheng; Cheaupun, Kunya; Jongdee, Supanee; Blanco, Pedro; Bryant, Rolfe; Thi Lang, Nguyen; Hall, Robert D.; Fitzgerald, Melissa

2014-01-01

With the ever-increasing global demand for high quality rice in both local production regions and with Western consumers, we have a strong desire to understand better the importance of the different traits that make up the quality of the rice grain and obtain a full picture of rice quality demographics. Rice is by no means a ‘one size fits all’ crop. Regional preferences are not only striking, they drive the market and hence are of major economic importance in any rice breeding / improvement strategy. In this analysis, we have engaged local experts across the world to perform a full assessment of all the major rice quality trait characteristics and importantly, to determine how these are combined in the most preferred varieties for each of their regions. Physical as well as biochemical characteristics have been monitored and this has resulted in the identification of no less than 18 quality trait combinations. This complexity immediately reveals the extent of the specificity of consumer preference. Nevertheless, further assessment of these combinations at the variety level reveals that several groups still comprise varieties which consumers can readily identify as being different. This emphasises the shortcomings in the current tools we have available to assess rice quality and raises the issue of how we might correct for this in the future. Only with additional tools and research will we be able to define directed strategies for rice breeding which are able to combine important agronomic features with the demands of local consumers for specific quality attributes and hence, design new, improved crop varieties which will be awarded success in the global market. PMID:24454799

Development of breeding materials in rice by use of induced mutation

International Nuclear Information System (INIS)

Amano, Etsuo

1988-01-01

On this 25th Gamma Field Symposium, it may be worth while to review the world situation of mutation breeding, the possibility expected to mutation methods suggested by the ever progressing genetics in rice plant, and some of the activities in the Institute of Radiation Breeding. By the help of a small computer, the key word search analysis of 'Mutation Breeding Newsletter and Mutation Breeding Review' was tried, and the results are included in this review to see the present status. The studies on artificially induced mutation suggested that the possibility of dominant mutation is less. It might be probable that the inactivation of genes is the mechanism of mutation. Still the possibility of using mutation breeding techniques for many genetic characters was suggested. After the experience for 25 years, detailed genetical and fine structure analyses became important. The studies on the expression of mutant phenotypes including molecular genetics will help to develop radiation breeding into an effective means to enrich the genetic resources for breeding. The situation in the world, the genes reported in rice, the possibility to induce useful mutants against environmental stress, the mutation in the protein content in grains, the mutants of storage carbohydrate, the possibility to widen gene resources and so on are reported. (Kako, I.)

Breeding of a new special rice variety Hangxiangnuo

International Nuclear Information System (INIS)

Zhou Hanqin; Pang Dajian; Fan Zhilan; Liu Chuanguang; Li Chen; Chen Jianyou

2011-01-01

A new special rice variety Hangxiangnuo was bred by several generation selections of the progeny of the rice variety Nanfengnuo which was carried by the spacecraft Shenzhou No 4. Hangxiangnuo was permitted to release by the Crop Examination and Approval Committee of Guangdong Province in January, 2009. Compared with its parent variety Nanfengnuo, Hangxiangnuo has better resistance to blast, greater length-width ratio of grain, more panicles per plant, filled grains per panicle and fragrance. The efficiency of space mutation breeding and the generation at which mutant traits become homozygous were also discussed in the paper. (authors)

Recent progress on the genetics and molecular breeding of brown planthopper resistance in rice.

Science.gov (United States)

Hu, Jie; Xiao, Cong; He, Yuqing

2016-12-01

Brown planthopper (BPH) is the most devastating pest of rice. Host-plant resistance is the most desirable and economic strategy in the management of BPH. To date, 29 major BPH resistance genes have been identified from indica cultivars and wild rice species, and more than ten genes have been fine mapped to chromosome regions of less than 200 kb. Four genes (Bph14, Bph26, Bph17 and bph29) have been cloned. The increasing number of fine-mapped and cloned genes provide a solid foundation for development of functional markers for use in breeding. Several BPH resistant introgression lines (ILs), near-isogenic lines (NILs) and pyramided lines (PLs) carrying single or multiple resistance genes were developed by marker assisted backcross breeding (MABC). Here we review recent progress on the genetics and molecular breeding of BPH resistance in rice. Prospect for developing cultivars with durable, broad-spectrum BPH resistance are discussed.

Recurrent population improvement of rice breeding facilitated with male sterility

International Nuclear Information System (INIS)

Fujimaki, Hiroshi

1982-01-01

A new rice breeding system has been developed, making use of genic male sterility to utilize diverse breeding materials and to promote genetic recombination. In this system, recurrent selection technique and introgressive hybridization were used to increase the frequencies of producing desired genotypes and to improve the population in succession. To promote genetic recombination by the recurrent selection technique, intermating within the population is necessary, and to introduce useful germ plasms by the introgressive hybridization, back crossing with new genetic material is necessary. These can be done efficiently by using the recessive alleles for male sterility, and the representative models for thisF type of breeding were presented. (Kaihara, S.)

Potential of mutation breeding in improving Indonesian local rice varieties

International Nuclear Information System (INIS)

Sobrizal

2016-01-01

Rice (Oryza sativa L.) is an important cereal crops for human nutrition, this species can be divided into sub-species i.e. Indica and Japonica. Japonica sub-species consists of Temprate and Tropical Japonica (it is called as Javanica) groups. Mostly Javanica group originated from Indonesia, the people mentioned as Indonesian local varieties, it was covering more than 8000 varieties. This paper aims is to discuss the potential of mutation breeding, success stories and on going activities improved genetically the local rice varieties. Indonesian local varieties have been tested naturally for resistance to biotic and abiotic stresses so that they become useful collections of genetic resources. They usually adapted well toa specific environment where they grow largely, having good aroma and eating quality, but they have some weakness such very long growth duration, susceptible to lodging, unresponsive to fertilizer, and low yield. Seed multiplication is usually conducted by collecting seeds from farmer's fields so that the seed quality, especially for seeds purity level is very low. Improvements of seed quality is usually conducted through purification of exciting varieties, then, the result is released as a new variety. Other ways, some new varieties were improved through mutation breeding, for example, an early maturing mutant variety of Pandan Putri derived from irradiated Pandan Wangi variety from Cianjur area. The success story to reduce harvest age of Pandan Wangi variety through mutation breeding, it was triggers other local governments to use nuclear technology in improving agronomic traits of their local rice varieties, without altered another good characters. (author)

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

Progress in the exploitation of new dwarfing genes in Chinese rice breeding

International Nuclear Information System (INIS)

Zhu, L.H.; Xie, Z.Q.

1990-01-01

Full text: Use of dwarfing genes in rice breeding in China began in the late 1950's. Since then, the major source of dwarfism has been 'Ai-zi-Zhan' with a gene allelic to sd-1 from 'Dee-Geo-Woo-Gen'. Since the 1970's, Chinese rice breeders paid attention to exploring new dwarfing gene sources and these efforts resulted in at least 7 sources non-allelic to sd-1. The late indica variety 'Gui-Yang-Ai No. 1' possessing gene dg(t) or sdg[t) proved to be most promising. The new sources include mutants induced by irradiation in 'Nanjing 11' and 'Nanjing 15'. The new genes are integrated in breeding to further improve plant type and adaptability. (author)

Induced mutation breeding for the improvement of rice in Malaysia

International Nuclear Information System (INIS)

Rusli Ibrahim; Abdul Rahim Harun; Ramli Othman; Farazi Johari; Asnah Hassan

2002-01-01

The first application of nuclear technology in mutation breeding for the improvement of rice was undertaken by the Malaysian Institute for Nuclear Technology Research (MINT) in December, 1984 for a Coordinated Research Programme under RCA/IAEA/FAO entitled Semi Dwarf Mutants for Rice Improvement in Asia and Pacific. The main objective was to generate semi dwarf mutants in both native and improved cultivars for possible use as new released cultivars or as parents in cross breeding programmes. Within five years, 101 semi dwarf mutants which have the potential to be used as new cultivars or as parents in cross breeding were identified. Twenty nine of the semi dwarf mutants have grain yield between 6000-7300 kg/ha which were classified as potentially good yielding mutants. The parent, Manik yielded about 5700 kg/ha. Forty seven mutants have grain yield between 5000 6000 kg/ha and 25 mutants yielded in the range of 4300-5000 kg/ha. Twelve mutants are resistant to BPH (brown planthopper) but only one, mutant ML15 has grain yield (6300 kg / ha) better than the parent. One of the most striking effects of radiation (gamma ray) was the formation of glutinous rice (Manik 817) with both good yield and head recovery. It is also interesting to note that one of the mutants (MA 03) shows a drastic change in its characteristics and performs better than the parent and other mutant lines. This mutant was late popularly known as mutant Tongkat Ali because of its: outstanding agronomic features such as very erect panicle even after grain filling, very strong culm and resistance to lodging. Even though this mutant was not officially released, due to its unique characteristics and high yield, it has been planted commercially by several farmers especially in the northern parts of Malaysia. More collaborative research programmes using induced mutation breeding have been carried out between MINT, MADA and also MARDI with the aim of producing new potential varieties with high yield, disease

Rice stem borers in Malaya. A proposal to use mutation breeding for their control

Energy Technology Data Exchange (ETDEWEB)

Vohra, F C [University of Malaya, Kuala Lumpur (Malaysia)

1970-03-01

. Various factors pertaining to the morphology, physiology and chemical nature of the rice plant are possibly responsible for the stem borer resistance. Carefully planned experiments have to evaluate their contribution to resistance before successful breeding programs can be undertaken. A wild species of rice in Malaya, Oryza ridleyi Hook. is said to be highly resistant. Similarly, several cultivated varieties are claimed to offer considerable resistance, but none of them can be recommended for commercial planting because of unsatisfactory yield, grain size and appearance, and nutrient and cooking value. Therefore, in order to develop a valuable resistant variety one would have to improve all the above characteristics. Mutation breeding with a high standard variety maybe more promising than a long-term cross-breeding program and should, in the opinion of the author, also be attempted in other countries. Through the co-operation of the authorities of the Serdang Agriculture College, the use of their paddy fields for observation and experimentation has been secured. Preliminary work to assess the type of borer and infestation in the most common rice-varieties namely Mahsuri, Malinja and Ria is already in progress. This is essential because most of the previous work on stem borers in Malaya has been carried out on older varieties which are not much favoured either by the government or by the people. All the four species mentioned earlier have been found attacking the new varieties at Serdang. At present, the data are too meagre to warrant any definite conclusions, but the following possibilities are indicated by the field observation. (a) Some species of borers are more common in one locality than other species, (b) In a particular locality there seems to be a quantitative host variety preference, (c) There is no indication of a relationship between the borer infestation and the habit of the plants, (d) Some varieties are possibly more vulnerable during younger stages. (e

Review of functional markers for improving cooking, eating, and the nutritional qualities of rice

Science.gov (United States)

Lau, Wendy C. P.; Rafii, Mohd Y.; Ismail, Mohd R.; Puteh, Adam; Latif, Mohammad A.; Ramli, Asfaliza

2015-01-01

After yield, quality is one of the most important aspects of rice breeding. Preference for rice quality varies among cultures and regions; therefore, rice breeders have to tailor the quality according to the preferences of local consumers. Rice quality assessment requires routine chemical analysis procedures. The advancement of molecular marker technology has revolutionized the strategy in breeding programs. The availability of rice genome sequences and the use of forward and reverse genetics approaches facilitate gene discovery and the deciphering of gene functions. A well-characterized gene is the basis for the development of functional markers, which play an important role in plant genotyping and, in particular, marker-assisted breeding. In addition, functional markers offer advantages that counteract the limitations of random DNA markers. Some functional markers have been applied in marker-assisted breeding programs and have successfully improved rice quality to meet local consumers’ preferences. Although functional markers offer a plethora of advantages over random genetic markers, the development and application of functional markers should be conducted with care. The decreasing cost of sequencing will enable more functional markers for rice quality improvement to be developed, and application of these markers in rice quality breeding programs is highly anticipated. PMID:26528304

Studies on mosquitoes (Diptera: Culicidae and anthropicenvironment: 5- Breeding of Anopheles albitarsis in flooded rice fields in South-Eastern Brazil

Directory of Open Access Journals (Sweden)

Oswaldo Paulo Forattini

1994-10-01

Full Text Available Studies on breeding Anopheles albitarsis and association with rice growth in irrigated paddy fields were carried out during the rice cultivation cycle from December 1993 to March 1994. This period corresponded to the length of time of permanent paddy flooding. Breeding occurred in the early stage up until five weeks after transplantation when rice plant height was small. That inverse correlation may give potential direction to control measures.

Study on space mutation breeding of rice

International Nuclear Information System (INIS)

Xu Jianlong; Lin Yizi; Xi Yongan; Jiang Xingcun; Li Jinguo

1997-01-01

Air-dried seeds of rice variety ZR9 were carried by high altitude balloon (HAB) and recoverable satellite (RS) for space mutation. Mutagentic effects of high altitude environment (HAE) of 30∼38 km and outer space environment (OSE) of 218∼326 km above sea level on rice plant were studied. The results indicated that the germination percentage (GP) of seeds was obviously lower than that of the controls. the mutation in plant height (PH) and growth period duration (GPD) of SP 1 carried by HAB were induced. However, the GP of seeds and characters of SP 1 carried by RS had no evident change. More stronger segregation of major characters such as PH, GPD and length of panicle, appeared in the two SP 2 generations resulting from HAB and RS. And their mutation frequency were 4.31% and 4.10% respectively. Mutation lines selected from the two mutation progenies improved significantly in PH, GPD, disease resistance and yield. Therefore, space mutation could be considered as a new breeding method

High-zinc rice as a breakthrough for high nutritional rice breeding program

Science.gov (United States)

Barokah, U.; Susanto, U.; Swamy, M.; Djoar, D. W.; Parjanto

2018-03-01

WHO reported climate change already takes 150,000 casualties annually, due to the emergence of various diseases and malnutrition caused by food shortages and disasters. Rice is the staple food for almost all of Indonesian citizens, therefore Zn biofortification on rice is expected to be effective, efficient, massive, and sustainable to overcome the Zn nutritional deficiency. This study aims to identify rice with high Zn content and yield for further effort in releasing this variety. Ten lines along with two varieties as a comparison (Ciherang and Inpari 5 Merawu) were tested in Plumbon Village, Mojolaban Subdistrict, Sukoharjo Regency during February-May 2017. The experiment was designed in a Randomized Completely Block Design with four replications on a 4 m x 5 m area, with 25 cm x 25 cm plant spacing using seedling transplanting techniques of 21 days old seeds. The results showed that the plant genotypes treated had differences in yield characteristics, heading date, harvest age, panicle number, filled and un-filled grain per panicle, seed set, 1000 grains weight, Zn and Iron (Fe) content in rice grain. B13884-MR-29-1-1 line (30.94 ppm Zn, 15.84 ppm Fe, 4.11 ton/ha yield) and IR 97477- 115-1-CRB-0-SKI-1-SKI-0-2 (29.61 ppm Zn, 13.49 ppm Zn, 4.4 ton/ha yield) are prospective variety to be released. Ciherang had Zn content of 23.04 ppm, 11.93 ppm Fe, and yield of 4.07 t/ha.

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)

The puzzle of Italian rice origin and evolution: determining genetic divergence and affinity of rice germplasm from Italy and Asia.

Directory of Open Access Journals (Sweden)

Xingxing Cai

Full Text Available The characterization of genetic divergence and relationships of a set of germplasm is essential for its efficient applications in crop breeding and understanding of the origin/evolution of crop varieties from a given geographical region. As the largest rice producing country in Europe, Italy holds rice germplasm with abundant genetic diversity. Although Italian rice varieties and the traditional ones in particular have played important roles in rice production and breeding, knowledge concerning the origin and evolution of Italian traditional varieties is still limited. To solve the puzzle of Italian rice origin, we characterized genetic divergence and relationships of 348 rice varieties from Italy and Asia based on the polymorphisms of microsatellite fingerprints. We also included common wild rice O. rufipogon as a reference in the characterization. Results indicated relatively rich genetic diversity (H(e = 0.63-0.65 in Italian rice varieties. Further analyses revealed a close genetic relationship of the Italian traditional varieties with those from northern China, which provides strong genetic evidence for tracing the possible origin of early established rice varieties in Italy. These findings have significant implications for the rice breeding programs, in which appropriate germplasm can be selected from a given region and utilized for transferring unique genetic traits based on its genetic diversity and evolutionary relationships.

Breeding and characterization of homokaryotic heteroplasmic male sterile lines in rice (oryza sativa)

International Nuclear Information System (INIS)

Mei, Q.; Zhou, X.; Liu, C.

2011-01-01

Twelve different Cytoplasmic Male-Sterile (CMS) lines were crossed with 18 rice varieties. From the hybrid with japonica rice Nongken 58, twelve homokaryotic-heteroplasmic male sterile lines were developed in B7F1 after successive back crossing and selection for stable male sterility and desirable agronomic traits such as flowering habit and high out crossing rate. The experimental results demonstrated that expression of the CMS factors were influenced by the corresponding nuclear genes. Three pollen abortion types, including the typical, the spherical and the stained abortion, were observed in the homokaryotic-heteroplasmic male sterile lines. Formation of the aborted pollen grains was influenced by the interaction among specific cytoplasmic and the corresponding nuclear genes. As the CMS carriers, these homokaryotic-heteroplasmic lines will have significant impact on the utilization of multiple types of CMS in hybrid rice breeding. What is more important is that these CMS lines are the invaluable materials for the investigation of the molecular mechanism of CMS formation in rice. (author)

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

Breeding of new rice varieties by gamma-rays

International Nuclear Information System (INIS)

Toda, Masayuki

1980-01-01

The breeding procedure for and the agronomic characteristics of some new rice varieties are reported. The seeds of the non-waxy variety ''Toyonishiki'' were exposed to 20 kR of gamma-ray. Two out of 20,000 panicles produced on these plants had waxy grain, and one of these brought forth a new commercial variety, ''Miyuki-mochi''. The yield of the new variety was reduced by 8% as compared with the original variety, but the heading date, culm length, panicle length and the number of panicles of the new variety were almost the same as those of the original variety. If compared with the old leading waxy variety, ''Shinano-mochi'', ''Miyuki-mochi'' is superior in yield by 15% and has high resistance to lodging and to rice blast. Seven other rice varieties were irradiated to obtain waxy mutants, and the frequency of R 1 panicles carrying waxy grains was found to be 1/10,000. There was marked difference in the 1,000 grain weight of these mutants relative to those of the respective original varieties and in amylose content among the waxy mutant strains. A new Saka-mai variety (for Sake brewing), ''Miyamanishiki'', was obtained from ''Takanenishiki'' (30 kR exposure of dry seeds). The most important character for Saka-mai is to have white-core grains. An experiment with several rice varieties showed that the frequency of white core grains was about 0.15% in the control and about 0.21% in the R 1 plants after irradiation. A desirable large grain strain, ''Shinho No. 12'', from ''Todorokiwase'', and a desirable mutant strain suitable as feed for domestic animals, ''Shinho No. 38'', from ''Toyonishiki'' were also obtained by gamma-ray irradiation. (Kaihara, S.)

Application of induced mutations and modern technologies for rice improvement at the Philippine Rice Research Institute (PhilRice)

International Nuclear Information System (INIS)

Padolina, Thelma F.

2015-01-01

The application of mutation techniques, i.e. gamma rays and other physical and chemical mutagens has generated a vast amount of genetic variability and has played a significant role in plant breeding and genetics. The widespread use of mutation techniques in plant breeding programs throughout the world has led to the official release of more than 3000 mutant varieties from different plant species. These varieties provide higher yields, better quality, resistance to diseases and resilience to climate change and variability. In the Philippine Rice Research Institute (PhilRice), classical induced mutagenesis and/or in combination with modern technologies as an important tool in rice breeding have been widely utilized by breeders. These recent advances offered new and exciting challenges for the development of new varieties. Moreover, it has the advantage of free regulatory restrictions imposed on genetically modified organisms. To date, high generation of new varieties, elite lines and pre-breeding materials have been derived from chemical and physical mutagenesis, another culture, in vitro mutagenesis, and molecular marker technologies. Directly benefitting the farmers are three Philippine released varieties: PSB Rc78 developed through gamma ray induction in year 2000; and NSIC Rc272 (2011) and Rc346 (2013) developed by combination of Co60 induction and another culture technology. These varieties are intended for the lowlands. In the current works, diverse mutant lines and pre-breeding materials of different target traits were generated and are now under evaluation as potential varieties and/or for use in the inbred and hybrid breeding programs. These genetic materials are in the background of traditional and modern rice varieties. Accordingly, for inbreds, mutated traits ranged from changes in morphological traits, yield, maturity, grain quality, nutritional traits, abiotic resistance such as heat, salinity, and drought tolerance, biotic resistance such as bacterial

Population dynamics and breeding patterns of multimammate mouse, Mastomys natalensis (Smith 1834), in irrigated rice fields in eastern Tanzania.

Science.gov (United States)

Mulungu, Loth S; Ngowo, Victoria; Mdangi, Mashaka; Katakweba, Abdul S; Tesha, Protas; Mrosso, Furaha P; Mchomvu, Mary; Sheyo, Paul M; Kilonzo, Bukhet S

2013-03-01

Multimammate mice are the most important vertebrate pests in Sub-Saharan Africa and are also reservoirs of many zoonotic diseases, including sylvan plague. This study investigated the population dynamics and breeding patterns of this mouse in irrigated rice cropping systems in eastern Tanzania. The multimammate mouse, Mastomys natalensis, population varied with habitat and months. Fallow land had a more abundant population than rice fields. The highest population peak was observed during the dry season from July to October. Mastomys natalensis is sexually active throughout the year in the study area, although it reaches the highest level in June and December when rice is at the maturity stage. This suggests that breeding is highly influenced by the presence of a rice crop in both seasons. More juvenile individuals were recorded in August and September, indicating that they were produced in the previous breeding months. The sex ratio of M. natalensis was not skewed to either males or females, indicating that it was at parity. Rodent population dynamics during the study periods in all habitats indicated that high birth rates accounted for the rapid population growth and turnover. Regular control and sustainable operations are thus essential if rodent pest populations are to be kept within tolerable limits. Copyright © 2012 Society of Chemical Industry.

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

Genome-wide association mapping for yield and other agronomic traits in an elite breeding population of tropical rice (Oryza sativa).

Science.gov (United States)

Begum, Hasina; Spindel, Jennifer E; Lalusin, Antonio; Borromeo, Teresita; Gregorio, Glenn; Hernandez, Jose; Virk, Parminder; Collard, Bertrand; McCouch, Susan R

2015-01-01

Genome-wide association mapping studies (GWAS) are frequently used to detect QTL in diverse collections of crop germplasm, based on historic recombination events and linkage disequilibrium across the genome. Generally, diversity panels genotyped with high density SNP panels are utilized in order to assay a wide range of alleles and haplotypes and to monitor recombination breakpoints across the genome. By contrast, GWAS have not generally been performed in breeding populations. In this study we performed association mapping for 19 agronomic traits including yield and yield components in a breeding population of elite irrigated tropical rice breeding lines so that the results would be more directly applicable to breeding than those from a diversity panel. The population was genotyped with 71,710 SNPs using genotyping-by-sequencing (GBS), and GWAS performed with the explicit goal of expediting selection in the breeding program. Using this breeding panel we identified 52 QTL for 11 agronomic traits, including large effect QTLs for flowering time and grain length/grain width/grain-length-breadth ratio. We also identified haplotypes that can be used to select plants in our population for short stature (plant height), early flowering time, and high yield, and thus demonstrate the utility of association mapping in breeding populations for informing breeding decisions. We conclude by exploring how the newly identified significant SNPs and insights into the genetic architecture of these quantitative traits can be leveraged to build genomic-assisted selection models.

Analysis of Plant Breeding on Hadoop and Spark

Directory of Open Access Journals (Sweden)

Shuangxi Chen

2016-01-01

Full Text Available Analysis of crop breeding technology is one of the important means of computer-assisted breeding techniques which have huge data, high dimensions, and a lot of unstructured data. We propose a crop breeding data analysis platform on Spark. The platform consists of Hadoop distributed file system (HDFS and cluster based on memory iterative components. With this cluster, we achieve crop breeding large data analysis tasks in parallel through API provided by Spark. By experiments and tests of Indica and Japonica rice traits, plant breeding analysis platform can significantly improve the breeding of big data analysis speed, reducing the workload of concurrent programming.

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.

Genomic prediction accounting for genotype by environment interaction offers an effective framework for breeding simultaneously for adaptation to an abiotic stress and performance under normal cropping conditions in rice

OpenAIRE

Ahmadi, Nourollah; Cao, Tuong-Vi; Valé, Giampiero; Bartholomé, Jérôme; Hassen, Manel

2018-01-01

Developing rice varieties adapted to alternate wetting and drying water management is crucial for the sustainability of irrigated rice cropping systems. Here we report the first study exploring the feasibility of breeding rice for adaptation to alternate wetting and drying using genomic prediction methods that account for genotype by environment interactions. Two breeding populations (a reference panel of 284 accessions and a progeny population of 97 advanced lines) were evaluated under alter...

New market opportunities for rice grains

Science.gov (United States)

Breeding efforts for rice have been focusing on increasing yield and improving quality (milling yield and grain quality), while maintaining cooked rice sensory properties to meet consumer preferences. These breeding targets will no doubt continue as the main foci for the rice industry. However, the ...

Application of accelerated argon ion radiation in rice breeding

International Nuclear Information System (INIS)

Deng Hong; Mei Mantong; Lu Yonggen; Yang, T.C.

1994-01-01

Dry seeds of rice 'Xiangzhou', a hsien (indica) variety, which has pleasant aroma but poor yield and originated in Guangdong Province, were irradiated by argon ion beam with the energy of 400 MeV/u to improve its agronomic traits. Three mutant lines, Ar-X-1-1, Ar-X-1-2 and Ar-X-2 were selected from M 1 or M 2 generation plants developed from seeds exposed to the dose of 100 Gy, and their economic potential in the M 5 generation was tested. The results showed that several traits of these lines were evidently improved when compared with the original variety. Plant height was reduced by 25% ∼ 39%, and growth period shortened by 8 ∼ 25 days. The effective panicle per plant was increased, and the resistance to bacterial leaf blight was improved. The grain yield per plot was increased by 14.34% ∼ 121.51%, which reached significant level in variance analysis, and the pleasant aroma was also retained. In addition, two mutants with traits of early maturity or semidwarf were found from the progenies of seeds exposured to the 150 Gy. The results suggest the potential application of heavy ion radiation in rice breeding

Studies on mosquitoes (Diptera: Culicidae) and anthropic environment: 6 - Breeding in empty conditions of rice fields in South-Eastern Brazil

OpenAIRE

Forattini,Oswaldo Paulo; Kakitani,Iná; Massad,Eduardo; Marucci,Daniel

1994-01-01

Studies on culicid breeding in empty rice fields were carried out during the cultivation cycle from May to November 1993. This period corresponded to stages 1 and 2, when empty conditions prevailed. Breeding occurred in stage 1 and the first part of stage 2, corresponding respectively to fallow uncultivated and ploughing situations. No breeding was found to take place during the second part of stage 2 when transient floods and harrowing occurred. The predominant species were Aedes scapularis,...

Application of gene targeting to designed mutation breeding of high-tryptophan rice.

Science.gov (United States)

Saika, Hiroaki; Oikawa, Akira; Matsuda, Fumio; Onodera, Haruko; Saito, Kazuki; Toki, Seiichi

2011-07-01

Site-directed mutagenesis via gene targeting (GT) based on homologous recombination is the ultimate mutation breeding technology because it enables useful information acquired from structural- and computational-based protein engineering to be applied directly to molecular breeding, including metabolic engineering, of crops. Here, we employed this rationale to introduce precise mutations in OASA2--an α-subunit of anthranilate synthase that is a key enzyme of tryptophan (Trp) biosynthesis in rice (Oryza sativa)--via GT, with subsequent selection of GT cells using a Trp analog. The expression level of OASA2 in plants homozygous and heterozygous for modified OASA2 was similar to that of nontransformants, suggesting that OASA2 transcription in GT plants was controlled in the same manner as endogenous OASA2, and that GT could lead to a lower risk of gene silencing than in conventional overexpression approaches. Moreover, we showed that enzymatic properties deduced from protein engineering or in vitro analysis could be reproduced in GT plants as evidenced by Trp accumulation levels. Interestingly, mature seeds of homozygous GT plants accumulated Trp levels 230-fold higher than in nontransformants without any apparent morphological or developmental changes. Thus, we have succeeded in producing a novel rice plant of great potential nutritional benefit for both man and livestock that could not have been selected using conventional mutagenesis approaches. Our results demonstrate the effectiveness of directed crop improvement by combining precision mutagenesis via GT with a knowledge of protein engineering.

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

Introduction and Utilization of INGER Rice Germplasm in China

Institute of Scientific and Technical Information of China (English)

TANGSheng-xiang; WEIXing-hua; ELJavier

2004-01-01

The International Network for Genetic Evaluation of Rice (INGER) is a global partnership between international and national agricultural research institutions. INGER focuses on worldwide exchange, evaluation and utilization of improved varieties and elite breeding lines of rice. China has actively participated in the activities of INGER since 1980.During the pasted years, 26 500 INGER entries with diversity genetic background have been introduced and evaluated by Chinese scientists. Among of them, 37 commercial varieties directly from elite INGER entries and 27 rice hybrids using INGER lines as their restorer lines/donors have been released to farmers in China. About 1 900 INGER entries were indirectly utilized as cross parents or pest resistant donors in various national and provincial rice breeding programs. Based on the incomplete statistics, there were 14.5 million cumulated hectares planting these varieties and hybrids, from which 5.44 MT of increased rough rice has been received by farmers. INGER accelerates the transfer of adapted varieties and hybrids to farmers, and increases the diversity of rice germplasm in cultivation. Therefore, INGER cooperation has made great benefit both in economy and society in China.

Introduction and Utilization of INGER Rice Germplasm in China

Institute of Scientific and Technical Information of China (English)

TANG Sheng-xiang; WEI Xing-hua; E L Javier

2004-01-01

The International Network for Genetic Evaluation of Rice (INGER) is a global partnership between international and national agricultural research institutions. INGER focuses on worldwide exchange, evaluation and utilization of improved varieties and elite breeding lines of rice. China has actively participated in the activities of INGER since 1980.During the pasted years, 26 500 INGER entries with diversity genetic background have been introduced and evaluated by Chinese scientists. Among of them, 37 commercial varieties directly from elite INGER entries and 27 rice hybrids using INGER lines as their restorer lines/donors have been released to farmers in China. About 1 900 INGER entries were indirectly utilized as cross parents or pest resistant donors in various national and provincial rice breeding programs. Based on the incomplete statistics, there were 14.5million cumulated hectares planting these varieties and hybrids, from which 5.44 MT of increased rough rice has been received by farmers. INGER accelerates the transfer of adapted varieties and hybrids to farmers, and increases the diversity of rice germplasm in cultivation. Therefore, INGER cooperation has made great benefit both in economy and society in China.

Ricebase: a breeding and genetics platform for rice, integrating individual molecular markers, pedigrees and whole-genome-based data.

Science.gov (United States)

Edwards, J D; Baldo, A M; Mueller, L A

2016-01-01

Ricebase (http://ricebase.org) is an integrative genomic database for rice (Oryza sativa) with an emphasis on combining datasets in a way that maintains the key links between past and current genetic studies. Ricebase includes DNA sequence data, gene annotations, nucleotide variation data and molecular marker fragment size data. Rice research has benefited from early adoption and extensive use of simple sequence repeat (SSR) markers; however, the majority of rice SSR markers were developed prior to the latest rice pseudomolecule assembly. Interpretation of new research using SNPs in the context of literature citing SSRs requires a common coordinate system. A new pipeline, using a stepwise relaxation of stringency, was used to map SSR primers onto the latest rice pseudomolecule assembly. The SSR markers and experimentally assayed amplicon sizes are presented in a relational database with a web-based front end, and are available as a track loaded in a genome browser with links connecting the browser and database. The combined capabilities of Ricebase link genetic markers, genome context, allele states across rice germplasm and potentially user curated phenotypic interpretations as a community resource for genetic discovery and breeding in rice. Published by Oxford University Press 2016. This work is written by US Government employees and is in the public domain in the United States.

Recurrent parent genome recovery analysis in a marker-assisted backcrossing program of rice (Oryza sativa L.).

Science.gov (United States)

Miah, Gous; Rafii, Mohd Y; Ismail, Mohd R; Puteh, Adam B; Rahim, Harun A; Latif, Mohammad A

2015-02-01

Backcross breeding is the most commonly used method for incorporating a blast resistance gene into a rice cultivar. Linkage between the resistance gene and undesirable units can persist for many generations of backcrossing. Marker-assisted backcrossing (MABC) along with marker-assisted selection (MAS) contributes immensely to overcome the main limitation of the conventional breeding and accelerates recurrent parent genome (RPG) recovery. The MABC approach was employed to incorporate (a) blast resistance gene(s) from the donor parent Pongsu Seribu 1, the blast-resistant local variety in Malaysia, into the genetic background of MR219, a popular high-yielding rice variety that is blast susceptible, to develop a blast-resistant MR219 improved variety. In this perspective, the recurrent parent genome recovery was analyzed in early generations of backcrossing using simple sequence repeat (SSR) markers. Out of 375 SSR markers, 70 markers were found polymorphic between the parents, and these markers were used to evaluate the plants in subsequent generations. Background analysis revealed that the extent of RPG recovery ranged from 75.40% to 91.3% and from 80.40% to 96.70% in BC1F1 and BC2F1 generations, respectively. In this study, the recurrent parent genome content in the selected BC2F2 lines ranged from 92.7% to 97.7%. The average proportion of the recurrent parent in the selected improved line was 95.98%. MAS allowed identification of the plants that are more similar to the recurrent parent for the loci evaluated in backcross generations. The application of MAS with the MABC breeding program accelerated the recovery of the RP genome, reducing the number of generations and the time for incorporating resistance against rice blast. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Rice genome mapping and its application in rice genetics and breeding

International Nuclear Information System (INIS)

Eun, M.Y.; Cho, Y.G.; Hahn, J.H.; Yoon, U.H.; Yi, B.Y.; Chung, T.Y.

1998-01-01

An 'MG' recombinant inbred population which consists of 164 F 13 lines has been developed from a cross between a Tongil type variety Milyang 23 and a Japonica type Gihobyeo by single seed descent. A Restriction Fragment Length Polymorphism (RFLP) framework map using this population has been constructed. Morphological markers, isozyme loci, microsatellites, Amplified Fragment Length Polymorphisms (AFLP), and new complementary DNA (cDNA) markers are being integrated in the framework map for a highly saturated comprehensive map. So far, 207 RFLPs, 89 microsatellites, 5 isozymes, 232 AFLPs, and 2 morphological markers have been mapped through international collaboration. The map contains 1,826 cM with an average interval size of 4.5 cM on the framework map and 3.4 cM overall (as of 29 October 1996). The framework map is being used for analyzing, quantitative trait loci (QTL) of agronomic characters and some physico-chemical properties relating to rice quality. The number of significant QTLs affecting each trait ranged from one to five, and 38 QTLs were detected for 17 traits. The percentage of variance explained by each QTL ranged from 5.6 to 66.9%. The isozyme marker, EstI-2, and two RFLP markers, RG109 and RG220, were linked most tightly at a distance less than 1 cM with the semidwarf (sd-1) gene on chromosome 1. These markers could be used for precise in vitro selection of individuals carrying the semidwarf gene using single seeds or very young leaf tissue, before this character is fully expressed. Appropriate application of marker-assisted selection, using EstI-2 and RFLP markers for the semidwarf character, in combination with other markers linked to genes of agronomic importance in rice, holds promise for improving, the efficiency of breeding, and the high-resolution genetic and physical mapping near sd-1, aimed at ultimately cloning this valuable gene

Accuracy of Genomic Selection in a Rice Synthetic Population Developed for Recurrent Selection Breeding.

Science.gov (United States)

Grenier, Cécile; Cao, Tuong-Vi; Ospina, Yolima; Quintero, Constanza; Châtel, Marc Henri; Tohme, Joe; Courtois, Brigitte; Ahmadi, Nourollah

2015-01-01

Genomic selection (GS) is a promising strategy for enhancing genetic gain. We investigated the accuracy of genomic estimated breeding values (GEBV) in four inter-related synthetic populations that underwent several cycles of recurrent selection in an upland rice-breeding program. A total of 343 S2:4 lines extracted from those populations were phenotyped for flowering time, plant height, grain yield and panicle weight, and genotyped with an average density of one marker per 44.8 kb. The relative effect of the linkage disequilibrium (LD) and minor allele frequency (MAF) thresholds for selecting markers, the relative size of the training population (TP) and of the validation population (VP), the selected trait and the genomic prediction models (frequentist and Bayesian) on the accuracy of GEBVs was investigated in 540 cross validation experiments with 100 replicates. The effect of kinship between the training and validation populations was tested in an additional set of 840 cross validation experiments with a single genomic prediction model. LD was high (average r2 = 0.59 at 25 kb) and decreased slowly, distribution of allele frequencies at individual loci was markedly skewed toward unbalanced frequencies (MAF average value 15.2% and median 9.6%), and differentiation between the four synthetic populations was low (FST ≤0.06). The accuracy of GEBV across all cross validation experiments ranged from 0.12 to 0.54 with an average of 0.30. Significant differences in accuracy were observed among the different levels of each factor investigated. Phenotypic traits had the biggest effect, and the size of the incidence matrix had the smallest. Significant first degree interaction was observed for GEBV accuracy between traits and all the other factors studied, and between prediction models and LD, MAF and composition of the TP. The potential of GS to accelerate genetic gain and breeding options to increase the accuracy of predictions are discussed.

Ion-beam technology for novel rice improvement

International Nuclear Information System (INIS)

Sobri Hussin; Azhar Mohammad; Abd Rahim Hussin; Rusli Ibrahim; Anna, L.P.K.

2009-01-01

In Malaysia, rice is the most important food crop and is cultivated in about 670,000 ha of arable land in the country. Conventional rice breeding carried out for the last 37 years resulted in the release of 34 modern varieties having an average yield of 5 t per/ha. The major objectives of the rice-breeding program in Malaysia are to develop high-yielding cultivars and to improve yield stability through higher levels of resistance to diseases, insect pests and other stresses. Most of these cultivars have been developed through conventional breeding. In this study, a new method through nuclear technology was used to develop novel superior cultivars. A total number of 100 seeds per dose (0, 10, 20, 40, 60, 80, 100, 120, 160, 200 Gy) of MR219 were exposed to carbone-ion irradiation (Ion Beam). The irradiated seeds were successfully planted under Controlled Environment Greenhouse for mutation frequency observation. After 2 months, it was revealed that the shoulder dose was significant obtained at 60 and 80 Gy. It was found that germination rates of the mutants were more than 60% for the doses range from 0 to 120 Gy and significantly decreased after 120 Gy. (Author)

Study on the breeding of japonical gelatinous rice mutant variety Zhenuo 36 with high yield and good grain quality

International Nuclear Information System (INIS)

Bao Genliang; Zhang Xiaoming; Ye Shenghai; Zuo Xiaoxu; Feng Zuocheng; Lu Wenwu; Katsura Toomita; Asako Kobayasi

2004-01-01

The dry seeds of F 2 , which came from the crossing of japonical rice Bing 92-124 x japonical gelatinous rice Shaonuoxuan (SNX), was induced by 200 Gy 60 Co γ-irradiation. A japonical gelatinous rice mutant ZH206 with high yield, large grain size and good grain quality was obtained through several generation selections. It was demonstrated that the average yield was 9.4% higher than controls in two regional tests in successive two years. Its grain size was obviously large as compared with its original parents, 1000-grain weight was above 30 g, 4.1 g and 3.6 g higher than Bing 92-124 and SNX, respectively. Gelatinous characteristic of its rice was better than control Xianghu 84 and also much better than SNX. In 2003, the mutant was denominated as 'Zhenuo 36' by Crop Variety Identification Committee of Zhejiang Province. As an excellent japonical gelatinous variety, Zhenuo 36 had both the largest rate of increasing yield and the highest grain weight in Zhejiang provincial regional tests of japonical rice during last 20 years. The successful breeding of the variety showed that irradiation induction is an effective method to simultaneously improve some characteristics in rice. (authors)

Genetic Diversity of Aromatic Rice Germplasm Revealed By SSR Markers

Directory of Open Access Journals (Sweden)

Saba Jasim Aljumaili

2018-01-01

Full Text Available Aromatic rice cultivars constitute a small but special group of rice and are considered the best in terms of quality and aroma. Aroma is one of the most significant quality traits of rice, and variety with aroma has a higher price in the market. This research was carried out to study the genetic diversity among the 50 aromatic rice accessions from three regions (Peninsular Malaysia, Sabah, and Sarawak with 3 released varieties as a control using the 32 simple sequence repeat (SSR markers. The objectives of this research were to quantify the genetic divergence of aromatic rice accessions using SSR markers and to identify the potential accessions for introgression into the existing rice breeding program. Genetic diversity index among the three populations such as Shannon information index (I ranged from 0.25 in control to 0.98 in Sabah population. The mean numbers of effective alleles and Shannon’s information index were 0.36 and 64.90%, respectively. Similarly, the allelic diversity was very high with mean expected heterozygosity (He of 0.60 and mean Nei’s gene diversity index of 0.36. The dendrogram based on UPGMA and Nei’s genetic distance classified the 53 rice accessions into 10 clusters. Analysis of molecular variance (AMOVA revealed that 89% of the total variation observed in this germplasm came from within the populations, while 11% of the variation emanated among the populations. These results reflect the high genetic differentiation existing in this aromatic rice germplasm. Using all these criteria and indices, seven accessions (Acc9993, Acc6288, Acc6893, Acc7580, Acc6009, Acc9956, and Acc11816 from three populations have been identified and selected for further evaluation before introgression into the existing breeding program and for future aromatic rice varietal development.

Genetic Diversity of Aromatic Rice Germplasm Revealed By SSR Markers.

Science.gov (United States)

Jasim Aljumaili, Saba; Rafii, M Y; Latif, M A; Sakimin, Siti Zaharah; Arolu, Ibrahim Wasiu; Miah, Gous

2018-01-01

Aromatic rice cultivars constitute a small but special group of rice and are considered the best in terms of quality and aroma. Aroma is one of the most significant quality traits of rice, and variety with aroma has a higher price in the market. This research was carried out to study the genetic diversity among the 50 aromatic rice accessions from three regions (Peninsular Malaysia, Sabah, and Sarawak) with 3 released varieties as a control using the 32 simple sequence repeat (SSR) markers. The objectives of this research were to quantify the genetic divergence of aromatic rice accessions using SSR markers and to identify the potential accessions for introgression into the existing rice breeding program. Genetic diversity index among the three populations such as Shannon information index ( I ) ranged from 0.25 in control to 0.98 in Sabah population. The mean numbers of effective alleles and Shannon's information index were 0.36 and 64.90%, respectively. Similarly, the allelic diversity was very high with mean expected heterozygosity ( H e ) of 0.60 and mean Nei's gene diversity index of 0.36. The dendrogram based on UPGMA and Nei's genetic distance classified the 53 rice accessions into 10 clusters. Analysis of molecular variance (AMOVA) revealed that 89% of the total variation observed in this germplasm came from within the populations, while 11% of the variation emanated among the populations. These results reflect the high genetic differentiation existing in this aromatic rice germplasm. Using all these criteria and indices, seven accessions (Acc9993, Acc6288, Acc6893, Acc7580, Acc6009, Acc9956, and Acc11816) from three populations have been identified and selected for further evaluation before introgression into the existing breeding program and for future aromatic rice varietal development.

Genetic Diversity of Aromatic Rice Germplasm Revealed By SSR Markers

Science.gov (United States)

Jasim Aljumaili, Saba; Sakimin, Siti Zaharah; Arolu, Ibrahim Wasiu; Miah, Gous

2018-01-01

Aromatic rice cultivars constitute a small but special group of rice and are considered the best in terms of quality and aroma. Aroma is one of the most significant quality traits of rice, and variety with aroma has a higher price in the market. This research was carried out to study the genetic diversity among the 50 aromatic rice accessions from three regions (Peninsular Malaysia, Sabah, and Sarawak) with 3 released varieties as a control using the 32 simple sequence repeat (SSR) markers. The objectives of this research were to quantify the genetic divergence of aromatic rice accessions using SSR markers and to identify the potential accessions for introgression into the existing rice breeding program. Genetic diversity index among the three populations such as Shannon information index (I) ranged from 0.25 in control to 0.98 in Sabah population. The mean numbers of effective alleles and Shannon's information index were 0.36 and 64.90%, respectively. Similarly, the allelic diversity was very high with mean expected heterozygosity (He) of 0.60 and mean Nei's gene diversity index of 0.36. The dendrogram based on UPGMA and Nei's genetic distance classified the 53 rice accessions into 10 clusters. Analysis of molecular variance (AMOVA) revealed that 89% of the total variation observed in this germplasm came from within the populations, while 11% of the variation emanated among the populations. These results reflect the high genetic differentiation existing in this aromatic rice germplasm. Using all these criteria and indices, seven accessions (Acc9993, Acc6288, Acc6893, Acc7580, Acc6009, Acc9956, and Acc11816) from three populations have been identified and selected for further evaluation before introgression into the existing breeding program and for future aromatic rice varietal development. PMID:29736396

Breeding of Hangtian 36-an early-maturing variety of japonica rice by space mutation technique

International Nuclear Information System (INIS)

Wang Junmin; Luo Rongting; Bao Genliang; Zhang Mingxian; Xu Jianlong; Wu Wei

2007-01-01

Hangtian 36; an early-maturing late Japonica rice variety with high grain quality and disease resistance was developed from the mutagenesis progeny of Bing 1067 carried by the recoverable satellite. Hangtian 36 has advantages over the original variety Bing 1067 in mature duration, grain quality and blast resistance. It has strong tolerant ability to late sow, varying from sowing date of single cropping to the end of July. So it is an ideal variety suitable for the use of emergency situation, such as in the natural disaster year resulting from typhoon. This variety was officially registered by Zhejiang Committee on Variety Registration in 2006, and is adaptable in the region of Zhejiang province and the Yangtze River delta. The successful breeding of Hangtian 36 showed that space mutation is an effective method of simultaneous improvement for multiple traits of rice. (authors)

Breeding strategies for north central tree improvement programs

Science.gov (United States)

Ronald P. Overton; Hyun Kang

1985-01-01

The rationales and concepts of long-term tree breeding are discussed and compared with those for short-term breeding. A model breeding program is reviewed which maximizes short-term genetic gain for currently important traits and provides genetic resources that can be used effectively in future short-term breeding. The resources of the north-central region are examined...

Cold tolerance evaluation in Chilean rice genotypes at the germination stage

Directory of Open Access Journals (Sweden)

Gabriel Donoso Ñanculao

2013-03-01

Full Text Available Low temperature is the most important abiotic stress affecting rice (Oryza sativa L. yield in Chile. Rice in Chile is usually planted when the minimum air temperatures are below 12 °C. This temperature is lower than the optimum needed for normal rice germination. Therefore, the aim of this study was to evaluate cold tolerance in 20 experimental lines from the Rice Breeding Program of the Instituto de Investigaciones Agropecuarias (INIA, Chile, at the germination stage. Coleoptile length reduction (CRED, coleoptile length after cold treatment (CLEN, coleoptile length recovery (CREC, and coleoptile regrowth (CREG were evaluated at 13 °C for 4 d using 'Diamante-INIA' as the cold-tolerant control. To find genotypes with cold tolerance (low CRED value and high CLEN, CREC, and CREG values, genotypes were ranked, a biplot of principal components, and cluster analysis were performed. No differences were found among genotypes in the ranking based on CREC value so this trait was not considered. Analysis showed that only three experimental lines had cold tolerance similar to that of 'Diamante-INIA'; all other experimental lines exhibited intermediate to low cold tolerance. These results showed low cold tolerance of some Chilean genotypes at the germination stage, thus confirming the need to evaluate the rest of the germplasm from the Rice Breeding Program.

Induction of drought tolerant mutants of rice

International Nuclear Information System (INIS)

El-Hissewy, A.A.; Abd Allah, A.

2001-01-01

The ultimate goal of crop breeding is to develop varieties with a high yield potential and desirable agronomic characteristics. In Egypt, the most important qualities sought by breeders have been high yield potential, resistance to major diseases and insects, and improved grain and eating quality. However, breeding efforts should concentrate on varieties with the potential to minimize yield losses under unfavorable conditions such as drought, and to maximize yields when conditions are favorable. Rice (Oryza sativa L.) in Egypt is completely irrigated and a significant portion of the rice cultivated area is subject to water deficit resulting from an inadequate or insufficient irrigation supply. Drought tolerance is a complex trait in that it results from the interaction of histological and physiological characters of plant with environmental factors, both above-ground and under-ground. Accordingly, root characters are closely related to drought tolerance. Little attention has been paid in Egyptian breeding programs to root characters and their relation to shoot characters. Furthermore, induced mutations are considered as one of the most important methods to induce useful mutants, especially with improved root characters, to overcome the drought problem. The present investigation aimed to study the effect of different doses of gamma rays on several characters of three Egyptian rice varieties, i.e. 'Giza 171', 'Giza 175' and 'Giza 176' and to induce one or more mutants possessing drought tolerance

Use of physical/chemical mutagens in plant breeding program in Vietnam

International Nuclear Information System (INIS)

Tran Duy Quy; Nguyen Huu Dong; Bui Huy Thuy; Le Van Nha; Nguyen Van Bich

2001-01-01

Among more than 1870 new plant varieties formed by mutation breeding in the world, 44 varieties of different plants were formed by Vietnamese scientists. Research on induced mutation in Vietnam started in 1966, was promoted in Agricultural Institute, Cuu Long Delta Rice Research Institute, Institute of Food Crop Research, and Agriculture Universities, and has produced varieties of rice, maize, soybean, peanut, tomato, jujuba, green bean etc using physical and chemical mutagens: Irradiation with gamma rays or neutrons, and use of such chemicals as dimethylsulfate (DMS), diethylsulfate (DES), ethyleneimine (EI), N-nitrosomethylurea (NUM), N-nitrosoethylurea (NEU), and sodium azide (NaN 3 ). In the present report, the results of cytological and genetic effects in M1 plants, the frequency and spectrum of chlorophyll and morphological mutants, the mutants obtained and the genetic nature of the next generation are described, particularly for the case of rice. Radiation dose and dose rate used as mutagens are also reported. (S. Ohno)

Use of physical/chemical mutagens in plant breeding program in Vietnam

Energy Technology Data Exchange (ETDEWEB)

Tran Duy Quy; Nguyen Huu Dong; Bui Huy Thuy; Le Van Nha; Nguyen Van Bich [Agricultural Genetics Institute, Hanoi (Viet Nam)

2001-03-01

Among more than 1870 new plant varieties formed by mutation breeding in the world, 44 varieties of different plants were formed by Vietnamese scientists. Research on induced mutation in Vietnam started in 1966, was promoted in Agricultural Institute, Cuu Long Delta Rice Research Institute, Institute of Food Crop Research, and Agriculture Universities, and has produced varieties of rice, maize, soybean, peanut, tomato, jujuba, green bean etc using physical and chemical mutagens: Irradiation with gamma rays or neutrons, and use of such chemicals as dimethylsulfate (DMS), diethylsulfate (DES), ethyleneimine (EI), N-nitrosomethylurea (NUM), N-nitrosoethylurea (NEU), and sodium azide (NaN{sub 3}). In the present report, the results of cytological and genetic effects in M1 plants, the frequency and spectrum of chlorophyll and morphological mutants, the mutants obtained and the genetic nature of the next generation are described, particularly for the case of rice. Radiation dose and dose rate used as mutagens are also reported. (S. Ohno)

Assessing The Representative And Discriminative Ability Of Test Environments For Rice Breeding In Malaysia Using GGE Biplot

Directory of Open Access Journals (Sweden)

Yusuff Oladosu

2017-11-01

Full Text Available Identification of outstanding rice genotype for target environments is complicated by genotype environment interactions. Using genotype main effect plus genotype by environment interaction GGE Biplot software fifteen rice genotypes were evaluated at five locations representing the major rice producing areas in peninsula Malaysia in two cropping seasons to i identify ideal test environment for selecting superior rice genotype and ii identify discriminative and representative ability of test locations. Genotypes locations years and genotypes by environment interaction effect revealed high significant difference P 0.01 for number of tillers per hill grains per panicle grain weight per hill and yield per hectare. Grain yield per hectare had a non-repeatable crossover pattern that formed a complex and single mega-environment. Based on the crossover pattern a set of cultivars were selected for the whole region on the merit of mean performance and their stability analysis. The tested environments were divided into two mega-environments. An ideal test environment that measures the discriminative and representative ability of test location reveal that environment Sekinchan SC is the best environment while Kedah KD and Penang PN can also be considered as favorable environment whereas Serdang SS and Tanjung Karang TK were the poorest locations for selecting genotypes adapted to the whole region. This study serves a reference for genotypes evaluation as well as identification of test locations for rice breeding in Malaysia.

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.

Diversity of global rice markets and the science required for consumer-targeted rice breeding

Science.gov (United States)

With the ever-increasing global demand for high quality rice in both local production regions and with Western consumers, we have a strong desire to understand better the importance of different quality traits that make up the rice grain and obtain a full picture of rice quality demographics. Rice ...

Accuracy of Genomic Selection in a Rice Synthetic Population Developed for Recurrent Selection Breeding.

Directory of Open Access Journals (Sweden)

Cécile Grenier

Full Text Available Genomic selection (GS is a promising strategy for enhancing genetic gain. We investigated the accuracy of genomic estimated breeding values (GEBV in four inter-related synthetic populations that underwent several cycles of recurrent selection in an upland rice-breeding program. A total of 343 S2:4 lines extracted from those populations were phenotyped for flowering time, plant height, grain yield and panicle weight, and genotyped with an average density of one marker per 44.8 kb. The relative effect of the linkage disequilibrium (LD and minor allele frequency (MAF thresholds for selecting markers, the relative size of the training population (TP and of the validation population (VP, the selected trait and the genomic prediction models (frequentist and Bayesian on the accuracy of GEBVs was investigated in 540 cross validation experiments with 100 replicates. The effect of kinship between the training and validation populations was tested in an additional set of 840 cross validation experiments with a single genomic prediction model. LD was high (average r2 = 0.59 at 25 kb and decreased slowly, distribution of allele frequencies at individual loci was markedly skewed toward unbalanced frequencies (MAF average value 15.2% and median 9.6%, and differentiation between the four synthetic populations was low (FST ≤0.06. The accuracy of GEBV across all cross validation experiments ranged from 0.12 to 0.54 with an average of 0.30. Significant differences in accuracy were observed among the different levels of each factor investigated. Phenotypic traits had the biggest effect, and the size of the incidence matrix had the smallest. Significant first degree interaction was observed for GEBV accuracy between traits and all the other factors studied, and between prediction models and LD, MAF and composition of the TP. The potential of GS to accelerate genetic gain and breeding options to increase the accuracy of predictions are discussed.

CORRELATION ANALYSIS OF AGRONOMIC CHARACTERS AND GRAIN YIELD OF RICE FOR TIDAL SWAMP AREAS

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Aris Hairmansis

2013-05-01

Full Text Available Development of rice varieties for tidal swamp areas is emphasized on the improvement of rice yield potential in specific environment. However, grain yield is a complex trait and highly dependent on the other agronomic characters; while information related to the relationship between agronomic characters and grain yield in the breeding program particularly for tidal swamp areas is very limited. The objective of this study was to investigate relationship between agronomic characters and grain yield of rice as a basis for selection of high yielding rice varieties for tidal swamp areas. Agronomic characters and grain yield of nine advanced rice breeding lines and two rice varieties were evaluated in a series of experiments in tidal swamp areas, Karang Agung Ulu Village, Banyuasin, South Sumatra, for four cropping seasons in dry season (DS 2005, wet season (WS 2005/2006, DS 2006, and DS 2007. Result from path analysis revealed that the following characters had positive direct effect on grain yield, i.e. number of productive tillers per hill (p = 0.356, number of filled grains per panicle (p = 0.544, and spikelet fertility (p = 0.215. Plant height had negative direct effect (p = -0.332 on grain yield, while maturity, number of spikelets per panicle, and 1000-grain weight showed negligible effect on rice grain yield. Present study suggests that indirect selection of high yielding tidal swamp rice can be done by selecting breeding lines which have many product tive tillers, dense filled grains, and high spikelet fertility.

Induction of mutations in Thai rice varieties and subsequent selection and testing of beneficial mutant lines

Energy Technology Data Exchange (ETDEWEB)

Dasananda, S; Khambanonda, P [Ministry of Agriculture, Bangkok (Thailand)

1970-03-01

Ionizing radiations were first used in the Thailand Rice Breeding Program in 1955 when seeds of two recommended varieties were sent to the United States of America for treatment. As a result, five promising mutant lines are at present in regional yield tests where they are being considered for recommendation to rice growers. During the period 1960-1961 an unsuccessful attempt was made to induce resistance to blast in three susceptible varieties by exposing seeds to a local source of ionizing radiation In 1964, after an elapse of about 4 years, another attempt was made to utilize ionizing radiations in the breeding program by treating seeds of two recommended varieties. In 1965, a co-ordinated rice mutation breeding program was initiated under the auspices of the Joint FAO/IAEA Division of Atomic Energy in Food and Agriculture which resulted in treating seeds of twelve different rice varieties with both ethyl methane sulphonate and gamma rays from a {sup 60}Co gamma cell. The results so far indicate that mutagenic agents have been successful in producing genetic variability. Differences in heading date, mature plant height and plant type are frequently observed in the M{sub 2} and M{sub 3} generations. Several lines obtained from two of the irradiated varieties have exhibited a higher degree of resistance to blast than the parental material. From 15-kR treatments of non-glutinous varieties, mutants with glutinous endosperm have been obtained. Not all varieties gave the same response to treatment. (author)

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

Genetic resources in maize breeding

Directory of Open Access Journals (Sweden)

Anđelković Violeta

2017-01-01

Full Text Available Maize, wheat and rice are the most important cereals grown in the world. It is predicted that by 2025 maize is likely to become the crop with the greatest production globally. Conservation of maize germplasm provides the main resources for increased food and feed production. Conservation in gene banks (ex-situ is dominant strategy for maize conservation. More than 130 000 maize accessions, e.g. about 40% of total number, are stored in ten largest gene banks worldwide and Maize Research Institute Zemun Polje (MRIZP gene bank, with about 6000 accessions, is among them. Organized collecting missions started in 1961. in the former Yugoslavian territory, and up today, more than 2000 local maize landraces were stored. Pre-breeding activities that refer to identification of desirable traits from unadapted germplasm within genebank, result in materials expected to be included in breeding programs. Successful examples are LAMP, GEM and GENRES projects. At the end of XX century, at MRIZP genebank two pre-breeding activities were undertaken: eco-core and elite-core collections were created and landraces fulfilled particular criteria were chosen. In the last decade, MRIZP genebank collection was used for identification of sources for drought tolerance and improved grain quality. According to agronomic traits and general combining ability, two mini-core collections were created and included in commercial breeding programs.

Plant breeding and genetics newsletter. No. 13

International Nuclear Information System (INIS)

2004-06-01

This issue reports on the creation of the Agency's Subprogramme of Sustainable Intensification of Crop Production Systems (E1) through the merger of the Soils and Plant Breeding and Genetics Subprogrammes together with part of the Entomology Subprogramme activities. Implementation of a new Coordinated Research Project (CRP) on the Effects of Mutagenic Agents on the DNA Sequence in Plants, and the successful submission of a new CRP proposal on Pyramiding of Mutated Genes Contributing to Crop Quality and Resistance to Stress Affecting Quality were among the major activities of our Subprogramme during the last six months. We actively participated in the International Year of Rice (IYR 2004) events such as the Meeting of the Informal International Working Group on the International Year of Rice (IIWG) and the FAO Rice Conference on Rice in Global Markets and Sustainable Production Systems (Rome, Italy), both in February this year. A lot of work has been concentrated this last semester on the preparation of Programme and Budget for the biennium 2006-2007 and the appraisal of TC proposals for the biennium 2005-2006. The Mutation Breeding Newsletter and the Mutation Breeding Review will merge to become the Mutation Breeding Newsletter and Reviews (MBN and R). Starting at the end of July, the MBN and R will appear on a regular basis

Status of biotechnology with emphasis on molecular techniques for mutation breeding in the Philippines

Energy Technology Data Exchange (ETDEWEB)

Lapade, A.G.; Nazarea, T.Y.; Veluz, A.M.S.; Marbella, L.J.; Nato, A.Q.; Coloma, C.B. Jr.; Asencion, A.B. [Philippine Nuclear Research Institute, Commonwealth Avenue, Quezon (Philippines)

2002-02-01

This paper summarizes the status of biotechnology with emphasis on molecular techniques for plant breeding in the Philippines. Several molecular and in-vitro culture techniques are integrated in plant breeding for crop improvement at PNRI, UPLB, IRRI and PhilRice. At IRRI, PCR techniques, RFLP and RAPD, PCR techniques, RFLP and RAPD were developed to establish high density molecular maps, determine breadth and diversity of germplasm and characterize alien introgression. The molecular maps have identified DNA sequence of resistance genes of HYVs and NPTs to abiotic and biotic stresses, the major achievement is the development of high density molecular maps in rice with at least 2000 markers. The biotechnology program at PhilRice for varietal improvement includes: (1) utilization of molecular marker technology such gene mapping of desired traits in rice, analysis of genetic relationships of germplasm materials and breeding lines through DNA fingerprinting and genetic diversity studies and development and application of marker aided selection for disease resistance (RTD and BLB); (2) application of in-vitro techniques in the development of lines with tolerance to adverse conditions; (3) molecular cloning of important genes for RTD resistance; (4) genetic transformation for male sterility and resistance to sheath blight and stem borers; and (5) transfer of disease resistance from wild species to cultivated varieties. In IPB, molecular markers:microsatellites or SSR, AFLP and RGA are being used for mapping and diversity studies in coconut, mango, banana, mungbean, corn and tomato. Mutation breeding at PNRI using gamma radiation has resulted in the development of crop varieties with desirable traits. The use of AFLP coupled to PCR is being used to study polymorphism in plant variants of radiation-induced mutants of rice, pineapple and ornamentals. (author)

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.

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 ...

Current Status of Conventional and Molecular Interventions for Blast Resistance in Rice

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Deepti Srivastava

2017-11-01

Full Text Available Pyricularia oryzae anamorph of Magnaporthe oryzae is one of the most notorious fungal pathogens causing severe economic loss in rice production worldwide. Various methods, viz. cultural, biological and molecular approaches, are utilized to counteract this pathogen. Moreover, some tolerant or resistant rice varieties have been developed with the help of breeding programmes. Isolation and molecular characterization of different blast resistance genes now open the gate for new possibilities to elucidate the actual allelic variants of these genes via various molecular breeding and transgenic approaches. However, the behavioral pattern of this fungus breakups the resistance barriers in the resistant or tolerant rice varieties. This host-pathogen barrier will be possibly countered in future research by comparative genomics data from available genome sequence data of rice and M. oryzae for durable resistance. Present review emphasized fascinating recent updates, new molecular breeding approaches, transgenic and genomics approaches (i.e. miRNA and genome editing for the management of blast disease in rice. The updated information will be helpful for the durable, resistance breeding programme in rice against blast pathogen.

Use of nuclear and biotechnological methods to improve drought tolerance in rice an tomato crops

International Nuclear Information System (INIS)

Gonzalez, Maria C.; Suarez, Lorenzo; Mukandama, Jean P.; Mansoor, Mohamed Ali; Cristo, Elizabeth; Perez, Noraida; Fuentes, Jorge L.; Rodriguez, Yanet

2001-01-01

Drought is a limiting factor in the production of different crops and programs for to drought tolerance through mutation inductions are taking place in many countries. At The National Institute of Agricultural Science had been development an Program Breeding in order to obtained new rice an tomato varieties adapted to different drought conditions. For this purposes were irradiated with protons and gamma rays of 60Co different local varieties. Promising line were selected in drought condition during six generation. Was possible to obtain one rice and three tomato drought tolerant genotypes

In-vitro vs in-vivo Inoculation: Screening for Resistance of Australian Rice Genotypes Against Blast Fungus

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Vineela Challagulla

2015-05-01

Full Text Available To assist with rapid screening for rice blast resistance as a precursor in a breeding program, the susceptibility to rice blast of 13 rice genotypes from Australia was evaluated in May to June 2013 using three distinct inoculation methods (spot, filter paper and standard methods at seedling, vegetative and reproductive stages. The results revealed that the spot and filter paper inoculation methods were successful in discerning susceptibility to the rice blast disease (P ≤ 0.05. Disease susceptibility declined significantly from the vegetative to reproductive stages. The standard method was conducted at three different stages for pot plants grown inside the mist house. However, low temperatures did not produce disease symptoms except in a few genotypes. Among the 13 rice genotypes screened, AAT9 expressed a highly resistant response, and AAT4, AAT6, AAT10, AAT11, AAT13, AAT17 and AAT18 expressed resistance at various stages. The results will be useful for selecting elite genotypes for disease tolerance where rice blast is prevalent. In addition, the resistant genotypes can serve as a gene pool used in breeding programmes to develop new resistant genotypes.

Identification of heterotic loci associated with yield-related traits in Chinese common wild rice (Oryza rufipogon Griff.).

Science.gov (United States)

Luo, Xiaojin; Wu, Shuang; Tian, Feng; Xin, Xiaoyun; Zha, Xiaojun; Dong, Xianxin; Fu, Yongcai; Wang, Xiangkun; Yang, Jinshui; Sun, Chuanqing

2011-07-01

Many rice breeding programs have currently reached yield plateaus as a result of limited genetic variability in parental strains. Dongxiang common wild rice (Oryza rufipogon Griff.) is the progenitor of cultivated rice (Oryza sativa L.) and serves as an important gene pool for the genetic improvement of rice cultivars. In this study, heterotic loci (HLs) associated with six yield-related traits were identified in wild and cultivated rice and investigated using a set of 265 introgression lines (ILs) of O. rufipogon Griff. in the background of the Indica high-yielding cultivar Guichao 2 (O. sativa L.). Forty-two HLs were detected by a single point analysis of mid-parent heterosis values from test cross F(1) offspring, and 30 (71.5%) of these HLs showed significantly positive effects, consistent with the superiority shown by the F(1) test cross population in the six yield-related traits under study. Genetic mapping of hsp11, a locus responsible for the number of spikelets per panicle, confirmed the utility of these HLs. The results indicate that favorable HLs capable of improving agronomic traits are available. The identification of HLs between wild rice and cultivated rice could lead to a new strategy for the application of heterosis in rice breeding. Copyright © 2011. Published by Elsevier Ireland Ltd.

ADAM: A computer program to simulate selective-breeding schemes for animals

DEFF Research Database (Denmark)

Pedersen, L D; Sørensen, A C; Henryon, M

2009-01-01

ADAM is a computer program that models selective breeding schemes for animals using stochastic simulation. The program simulates a population of animals and traces the genetic changes in the population under different selective breeding scenarios. It caters to different population structures......, genetic models, selection strategies, and mating designs. ADAM can be used to evaluate breeding schemes and generate genetic data to test statistical tools...

Developments in amphibian captive breeding and reintroduction programs.

Science.gov (United States)

Harding, Gemma; Griffiths, Richard A; Pavajeau, Lissette

2016-04-01

Captive breeding and reintroduction remain high profile but controversial conservation interventions. It is important to understand how such programs develop and respond to strategic conservation initiatives. We analyzed the contribution to conservation made by amphibian captive breeding and reintroduction since the launch of the International Union for Conservation of Nature (IUCN) Amphibian Conservation Action Plan (ACAP) in 2007. We assembled data on amphibian captive breeding and reintroduction from a variety of sources including the Amphibian Ark database and the IUCN Red List. We also carried out systematic searches of Web of Science, JSTOR, and Google Scholar for relevant literature. Relative to data collected from 1966 to 2006, the number of species involved in captive breeding and reintroduction projects increased by 57% in the 7 years since release of the ACAP. However, there have been relatively few new reintroductions over this period; most programs have focused on securing captive-assurance populations (i.e., species taken into captivity as a precaution against extinctions in the wild) and conservation-related research. There has been a shift to a broader representation of frogs, salamanders, and caecilians within programs and an increasing emphasis on threatened species. There has been a relative increase of species in programs from Central and South America and the Caribbean, where amphibian biodiversity is high. About half of the programs involve zoos and aquaria with a similar proportion represented in specialist facilities run by governmental or nongovernmental agencies. Despite successful reintroduction often being regarded as the ultimate milestone for such programs, the irreversibility of many current threats to amphibians may make this an impractical goal. Instead, research on captive assurance populations may be needed to develop imaginative solutions to enable amphibians to survive alongside current, emerging, and future threats. © 2015

R and D activities on radiation induced mutation breeding

International Nuclear Information System (INIS)

Lapade, A.G.; Asencion, A.B.; Santos, I.S.; Grafia, A.O.; Veluz, AM.S.; Barrida, A.C.; Marbella, L.J.

1996-01-01

This paper summarizes the accomplishments, prospects and future plans of mutation breeding for crop improvement at the Philippine Nuclear Research Institute (PNRI). Mutation induction has become a proven way creating variation within a crop variety and inducing desired attributes that cannot be found in nature or have been lost during evolution. Several improved varieties with desirable traits were successfully developed through induced mutation breeding at our research institute. In rice, mutation breeding has resulted in the development of new varieties: (1) PARC 2, (2) Milagrosa mutant, (3) Bengawan mutant and (4) Azmil mutant. Mutation breeding in leguminous crops has led to the induction of an improved L 114 soybean mutant that is shorter that the original variety but yield about 40% more. Several PAEC mungbean varieties characterized with long pods that are non-shattering were also induced. In asexually propagated crops, an increase in yield and chlorophyll mutants were obtained in sweet potatos. Likewise, chlorophyll mutant which look-like 'ornamental bromeliads' and a mutant with reduced spines have been developed in pineapple Queen variety. At present, we have started a new project in mutation breeding in ornamentals. Tissue culture is being utilized in our mutation breeding program. In the near future, radiation induced mutagenesis coupled with in vitro culture techniques on protoplast culture and somatic hybridization will be integrated into our mutation breeding program to facilitate the production of new crop varieties. (author)

Conserved Transcriptional Regulatory Programs Underlying Rice and Barley Germination

Science.gov (United States)

Lin, Li; Tian, Shulan; Kaeppler, Shawn; Liu, Zongrang; An, Yong-Qiang (Charles)

2014-01-01

Germination is a biological process important to plant development and agricultural production. Barley and rice diverged 50 million years ago, but share a similar germination process. To gain insight into the conservation of their underlying gene regulatory programs, we compared transcriptomes of barley and rice at start, middle and end points of germination, and revealed that germination regulated barley and rice genes (BRs) diverged significantly in expression patterns and/or protein sequences. However, BRs with higher protein sequence similarity tended to have more conserved expression patterns. We identified and characterized 316 sets of conserved barley and rice genes (cBRs) with high similarity in both protein sequences and expression patterns, and provided a comprehensive depiction of the transcriptional regulatory program conserved in barley and rice germination at gene, pathway and systems levels. The cBRs encoded proteins involved in a variety of biological pathways and had a wide range of expression patterns. The cBRs encoding key regulatory components in signaling pathways often had diverse expression patterns. Early germination up-regulation of cell wall metabolic pathway and peroxidases, and late germination up-regulation of chromatin structure and remodeling pathways were conserved in both barley and rice. Protein sequence and expression pattern of a gene change quickly if it is not subjected to a functional constraint. Preserving germination-regulated expression patterns and protein sequences of those cBRs for 50 million years strongly suggests that the cBRs are functionally significant and equivalent in germination, and contribute to the ancient characteristics of germination preserved in barley and rice. The functional significance and equivalence of the cBR genes predicted here can serve as a foundation to further characterize their biological functions and facilitate bridging rice and barley germination research with greater confidence. PMID

Engineered Dwarf Male-Sterile Rice: A Promising Genetic Tool for Facilitating Recurrent Selection in Rice.

Science.gov (United States)

Ansari, Afsana; Wang, Chunlian; Wang, Jian; Wang, Fujun; Liu, Piqing; Gao, Ying; Tang, Yongchao; Zhao, Kaijun

2017-01-01

Rice is a crop feeding half of the world's population. With the continuous raise of yield potential via genetic improvement, rice breeding has entered an era where multiple genes conferring complex traits must be efficiently manipulated to increase rice yield further. Recurrent selection is a sound strategy for manipulating multiple genes and it has been successfully performed in allogamous crops. However, the difficulties in emasculation and hand pollination had obstructed efficient use of recurrent selection in autogamous rice. Here, we report development of the dwarf male-sterile rice that can facilitate recurrent selection in rice breeding. We adopted RNAi technology to synergistically regulate rice plant height and male fertility to create the dwarf male-sterile rice. The RNAi construct pTCK-EGGE, targeting the OsGA20ox2 and OsEAT1 genes, was constructed and used to transform rice via Agrobacterium -mediated transformation. The transgenic T0 plants showing largely reduced plant height and complete male-sterile phenotypes were designated as the dwarf male-sterile plants. Progenies of the dwarf male-sterile plants were obtained by pollinating them with pollens from the wild-type. In the T1 and T2 populations, half of the plants were still dwarf male-sterile; the other half displayed normal plant height and male fertility which were designated as tall and male-fertile plants. The tall and male-fertile plants are transgene-free and can be self-pollinated to generate new varieties. Since emasculation and hand pollination for dwarf male-sterile rice plants is no longer needed, the dwarf male-sterile rice can be used to perform recurrent selection in rice. A dwarf male-sterile rice-based recurrent selection model has been proposed.

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...

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 ...

Determination of genetic variability of traditional varieties of Brazilian rice using microsatellite markers

Directory of Open Access Journals (Sweden)

Claudio Brondani

2006-01-01

Full Text Available The rice (Oryza sativa breeding program of the Rice and Bean research center of the Brazilian agricultural company Empresa Brasileira de Pesquisa Agropecuária (Embrapa is well established and provides new cultivars every year to attend the demand for improved high yielding varieties with tolerance to biotic and abiotic stresses. However, the elite genitors used to compose new populations for selection are closely related, contributing to the yield plateau reached in the last 20 years. To overcome this limit, it is necessary to broaden the genetic basis of the cultivars using diverse germplasm such as wild relatives or traditional varieties, with the latter being more practical because they are more easily crossed with elite germplasm to accelerate the recovery of modern plant types in the breeding lines. The objective of our study was to characterize the allelic diversity of 192 traditional varieties of Brazilian rice using 12 simple sequence repeat (SSR or microsatellite markers. The germplasm was divided into 39 groups by common name similarity. A total of 176 alleles were detected, 30 of which (from 23 accessions were exclusive. The number of alleles per marker ranged from 6 to 22, with an average of 14.6 alleles per locus. We identified 16 accessions as a mixture of pure lines or heterozygous plants. Dendrogram analysis identified six clusters of identical accessions with different common names and just one cluster with identical accessions with the same common name, indicating that SSR markers are fundamental to determining the genetic relationship between landraces. A subset of 24 landraces, representatives of the 13 similarity groups plus the 11 accessions not grouped, was the most variable set of genotypes analyzed. These accessions can be used as genitors to increase the genetic variability available to rice breeding programs.

The improvement of rice varieties for major pest and diseases resistance

International Nuclear Information System (INIS)

Sahi, I.; Silitonga, T.S.

1988-01-01

Since 1971, the rice breeding program in Indonesia has developed on intensive program to improve varieties for yield potential, resistancy to major pests and diseases, early maturity good grain and eating quality. In recent years, the attacks of insects and diseases are very severe in rice cultivation in Asia. Much of the losses were due to acontinuous planting or certain varieties. Between 1966 and 1973 tungro occured in epidemic proportions on separate occasions in Indonesia, Thailand, Nort East India, Bangladesh, and Philippine. Since 1973, investation of brown planthopper and green leafhopper several damaged rice crop in most parts of Indonesia. Presently, rice improvement are directed to develop high yielding rice varieties that are resistant to brown planthopper, ragged stunt virus, blast, green leafhopper, and gallmidge. Screening for pests and diseases are conducted in the laboratory as well as in the field. The adoption of those improved varieties by farmers has contributed greatly in our efforts to attain self sufficiency in rice production in Indonesia. GH 147 -M-40 krad-Pn-89 (irradiated Barito) showed resistant to brown planthopper biotype 1 and 2 and moderately resistant to biotype 3. Napa 40 krad-St-12 has resistant reaction to blast. (authors). 4 refs, 8 tabs

Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

Science.gov (United States)

Mahadtanapuk, S.; Teraarusiri, W.; Phanchaisri, B.; Yu, L. D.; Anuntalabhochai, S.

2013-07-01

Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60-80 keV to a beam fluence range of 2 × 1016-2 × 1017 ions/cm2. The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 106 spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11).

Multiple cold resistance loci confer the high cold tolerance adaptation of Dongxiang wild rice (Oryza rufipogon) to its high-latitude habitat.

Science.gov (United States)

Mao, Donghai; Yu, Li; Chen, Dazhou; Li, Lanying; Zhu, Yuxing; Xiao, Yeqing; Zhang, Dechun; Chen, Caiyan

2015-07-01

Dongxiang wild rice is phylogenetically close to temperate japonica and contains multiple cold resistance loci conferring its adaptation to high-latitude habitat. Understanding the nature of adaptation in wild populations will benefit crop breeding in the development of climate-resilient crop varieties. Dongxiang wild rice (DXWR), the northernmost common wild rice known, possesses a high degree of cold tolerance and can survive overwintering in its native habitat. However, to date, it is still unclear how DXWR evolved to cope with low-temperature environment, resulting in limited application of DXWR in rice breeding programs. In this study, we carried out both QTL mapping and phylogenetic analysis to discern the genetic mechanism underlying the strong cold resistance. Through a combination of interval mapping and single locus analysis in two genetic populations, at least 13 QTLs for seedling cold tolerance were identified in DXWR. A phylogenetic study using both genome-wide InDel markers and markers associated with cold tolerance loci reveals that DXWR belongs to the Or-III group, which is most closely related to cold-tolerant Japonica rice rather than to the Indica cultivars that are predominant in the habitat where DXWR grows. Our study paves the way toward an understanding of the nature of adaptation to a northern habitat in O. rufipogon. The QTLs identified in DXWR in this study will be useful for molecular breeding of cold-tolerant rice.

Mutation breeding and studies in wheat and rice

International Nuclear Information System (INIS)

Bhagwat, S.G.; Das, B.K.; Suman, Bakshi; Vikash Kumar, K.

2009-01-01

Wheat and rice are important part of average Indian diet. Efforts are needed to incorporate resistance to various biotic and abiotic stress factors, quality attributes and higher yield potential in the changing scenario. Radiation induced mutations can play important role in these crops as the variability among the cultivars is low. Mutants in wheat for earliness without affecting quality were selected. Grain shape mutants were isolated using computer based image analysis. In rice mutants with short stature in Basmati type and short stature in salinity tolerant background were isolated. Markers have been developed or validated to facilitate combining stress tolerance/quality and agronomic traits. Studies are underway to understand nature of reduced height mutant in wheat and disease mimic mutants in rice. (author)

100-year history of the development of bread winter wheat breeding programs

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М. А. Литвиненко

2016-05-01

Full Text Available Purpose. Review of the main achievements of the Wheat Breeding and Seed ProductionDepartment in the Plant Breeding and Genetic Institute – National Centre of Seed and Cultivar Investigation in the developing theoretical principles of breeding and creation of winter wheat varieties of different types during 100-year (1916–2016 period of breeding programs realization. Results. The main theoretical, methodical developments and breeding achievements of Wheat Breeding and Seed Production Department during 100-year (1916–2016 history have been considered. In the course of the Department activity, the research and metho­dology grounds of bread winter wheat breeding and seed production have been laid, 9 stages of breeding programs development have been accomplished. As a result, more than 130 varieties of different types have been created, 87 of them have been released in some periods or registered in the State registers of plants varieties of Ukraine and other countries and grown in the total sowing area about 220 million hectares.

Recent progress and future perspectives regarding mutation breeding at the Institute of Radiation Breeding

International Nuclear Information System (INIS)

Nakagawa, Hitoshi

2006-01-01

Number of mutation species in the world is stated by some literature. 202 species are bread in Japan, which consists of 151 (by radiation), 20 (chemicals) and 31 (culture). The mutation indirect use species obtained 176 of rice, 3 wheat, 6 barleys, 8 soybeans, 3 tomatoes and 4 others. Low allergen rice, low glutelin rice, globulin deletion rice, disease resistant pear and apple, chrysanthemum and rose by radiation were studied. Control of mutation, genetics analysis, molecular scientific determination of mutation such as scale of mutation and RNA interference are reported. Advanced Radiation Application Research Center was build in Korea, 2005. Malaysian Institute for Nuclear Technology Research (MINT) is being built in Malaysia. Forum for Nuclear Cooperation in Asia (FNCA) is promoting radiation breeding in Japan. (S.Y.)

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

Variation in cooking and eating quality traits in Japanese rice germplasm accessions.

Science.gov (United States)

Hori, Kiyosumi; Suzuki, Keitaro; Iijima, Ken; Ebana, Kaworu

2016-03-01

The eating quality of cooked rice is important and determines its market price and consumer acceptance. To comprehensively describe the variation of eating quality in 183 rice germplasm accessions, we evaluated 33 eating-quality traits including amylose and protein contents, pasting properties of rice flour, and texture of cooked rice grains. All eating-quality traits varied widely in the germplasm accessions. Principal-components analysis (PCA) revealed that allelic differences in the Wx gene explained the largest proportion of phenotypic variation of the eating-quality traits. In 146 accessions of non-glutinous temperate japonica rice, PCA revealed that protein content and surface texture of the cooked rice grains significantly explained phenotypic variations of the eating-quality traits. An allelic difference based on simple sequence repeats, which was located near a quantitative trait locus (QTL) on the short arm of chromosome 3, was associated with differences in the eating quality of non-glutinous temperate japonica rice. These results suggest that eating quality is controlled by genetic factors, including the Wx gene and the QTL on chromosome 3, in Japanese rice accessions. These genetic factors have been consciously selected for eating quality during rice breeding programs in Japan.

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

Science.gov (United States)

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.

Genomic Prediction Accounting for Genotype by Environment Interaction Offers an Effective Framework for Breeding Simultaneously for Adaptation to an Abiotic Stress and Performance Under Normal Cropping Conditions in Rice.

Science.gov (United States)

Ben Hassen, Manel; Bartholomé, Jérôme; Valè, Giampiero; Cao, Tuong-Vi; Ahmadi, Nourollah

2018-05-09

Developing rice varieties adapted to alternate wetting and drying water management is crucial for the sustainability of irrigated rice cropping systems. Here we report the first study exploring the feasibility of breeding rice for adaptation to alternate wetting and drying using genomic prediction methods that account for genotype by environment interactions. Two breeding populations (a reference panel of 284 accessions and a progeny population of 97 advanced lines) were evaluated under alternate wetting and drying and continuous flooding management systems. The predictive ability of genomic prediction for response variables (index of relative performance and the slope of the joint regression) and for multi-environment genomic prediction models were compared. For the three traits considered (days to flowering, panicle weight and nitrogen-balance index), significant genotype by environment interactions were observed in both populations. In cross validation, predictive ability for the index was on average lower (0.31) than that of the slope of the joint regression (0.64) whatever the trait considered. Similar results were found for progeny validation. Both cross-validation and progeny validation experiments showed that the performance of multi-environment models predicting unobserved phenotypes of untested entrees was similar to the performance of single environment models with differences in predictive ability ranging from -6% to 4% depending on the trait and on the statistical model concerned. The predictive ability of multi-environment models predicting unobserved phenotypes of entrees evaluated under both water management systems outperformed single environment models by an average of 30%. Practical implications for breeding rice for adaptation to alternate wetting and drying system are discussed. Copyright © 2018, G3: Genes, Genomes, Genetics.

Novel Chitinase Gene LOC_Os11g47510 from Indica Rice Tetep Provides Enhanced Resistance against Sheath Blight Pathogen Rhizoctonia solani in Rice

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Tilak R. Sharma

2017-04-01

Full Text Available Sheath blight disease (ShB, caused by the fungus Rhizoctonia solani Kühn, is one of the most destructive diseases of rice (Oryza sativa L., causing substantial yield loss in rice. In the present study, a novel rice chitinase gene, LOC_Os11g47510 was cloned from QTL region of R. solani tolerant rice line Tetep and used for functional validation by genetic transformation of ShB susceptible japonica rice line Taipei 309 (TP309. The transformants were characterized using molecular and functional approaches. Molecular analysis by PCR using a set of primers specific to CaMv 35S promoter, chitinase and HptII genes confirmed the presence of transgene in transgenic plants which was further validated by Southern hybridization. Further, qRT-PCR analysis of transgenic plants showed good correlation between transgene expression and the level of sheath blight resistance among transformants. Functional complementation assays confirmed the effectiveness of the chitinase mediated resistance in all the transgenic TP309 plants with varying levels of enhanced resistance against R. solani. Therefore, the novel chitinase gene cloned and characterized in the present study from the QTL region of rice will be of significant use in molecular plant breeding program for developing sheath blight resistance in rice.

AFLP-Based Analysis of Genetic Diversity, Population Structure, and Relationships with Agronomic Traits in Rice Germplasm from North Region of Iran and World Core Germplasm Set.

Science.gov (United States)

Sorkheh, Karim; Masaeli, Mohammad; Chaleshtori, Maryam Hosseini; Adugna, Asfaw; Ercisli, Sezai

2016-04-01

Analysis of the genetic diversity and population structure of crops is very important for use in breeding programs and for genetic resources conservation. We analyzed the genetic diversity and population structure of 47 rice genotypes from diverse origins using amplified fragment length polymorphism (AFLP) markers and morphological characters. The 47 genotypes, which were composed of four populations: Iranian native varieties, Iranian improved varieties, International Rice Research Institute (IRRI) rice varieties, and world rice collections, were analyzed using ten primer combinations. A total of 221 scorable bands were produced with an average of 22.1 alleles per pair of primers, of which 120 (54.30%) were polymorphic. The polymorphism information content (PIC) values varied from 0.32 to 0.41 with an average of 0.35. The high percentage of polymorphic bands (%PB) was found to be 64.71 and the resolving power (R p) collections were 63.36. UPGMA clustering based on numerical data from AFLP patterns clustered all 47 genotypes into three large groups. The genetic similarity between individuals ranged from 0.54 to 0.94 with an average of 0.74. Population genetic tree showed that Iranian native cultivars formed far distant cluster from the other populations, which may indicate that these varieties had minimal genetic change over time. Analysis of molecular variance (AMOVA) revealed that the largest proportion of the variation (84%) to be within populations showing the inbreeding nature of rice. Therefore, Iranian native varieties (landraces) may have unique genes, which can be used for future breeding programs and there is a need to conserve this unique diversity. Furthermore, crossing of Iranian genotypes with the genetically distant genotypes in the other three populations may result in useful combinations, which can be used as varieties and/or lines for future rice breeding programs.

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)

Developing climate resilient rice through genomics assisted breeding

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Valarmathi Muthu

2017-10-01

Full Text Available Rice is one of the major cereal food crops whose production has to be doubled to achieve the projected demand [1] and current yield trends are not sufficient to meet the projected growth in production. Increasing the rice production by 30% during 2030 needs overcoming challenges viz., yield plateau, declining land, water and labor resources and predicted effects of global climate change. Development of high performance rice genotypes with enhanced yield potential and resilience to climate change will help in sustained increase in rice production. Deployment of genomic technologies can accelerate development and delivery of improved germplasm with enhanced resilience and adaptability [2, 3]. In this context, the present study was undertaken with an aim of developing rice genotypes pyramided with QTLs/genes controlling tolerance against various biotic and abiotic stresses viz., bacterial leaf blight (xa13, Xa21, blast (Pi9, Gall midge (Gm4, drought (qDTY1.1 qDTY2.1, submergence (Sub1 and salinity (Saltol. CBMAS14065 an elite culture harboring QTLs controlling tolerance against drought, salinity and submergence was crossed with a donor harboring BLB, Blast and Gall midge resistant genes. True F1s were backcrossed with CBMAS14065 and BC1F1 progenies were subjected to foreground selection using markers linked to the target traits. Superior plants (18 of BC1F1 generation were subjected to background selection which revealed 71.42 - 86.90% recurrent parent (CBMAS14065 genome recovery. Selected BC1F1 plants were advanced to BC2F1 generation backcrossing with CBMAS14065. In BC2F1 generation, through foreground selection 6-8 QTL/gene positive plants have been selected and advanced for further evaluation. The superior lines with desired QTLs/genes will be subjected to rigorous phenotypic evaluation against target stresses and advanced further.

Screening for Osmotic Stress Responses in Rice Varieties under Drought Condition

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Simon Swapna

2017-09-01

Full Text Available Drought is the major abiotic stress factor that limits rice production worldwide. To evaluate the osmotic stress responses in rice varieties under drought condition, a total of 42 high-yielding rice varieties were collected from various research stations of Kerala Agricultural University in India. The experimental setup comprises of initial hydroponic treatments at different osmotic potentials, artificially induced by desired strengths of polyethylene glycol (PEG6000, and followed by the pot planted experiments in the rain-out-zone. The activities of antioxidant enzymes, relative water content, cell membrane stability, photosynthetic pigments, proline content, along with plant growth parameters of the varieties under drought condition were evaluated. Moreover, the standard scores of these rice varieties were assessed under stress and recovery conditions based on the scoring scale of the Standard Evaluation System for rice. Among the 42 rice varieties, we identified 2 rice varieties, Swarnaprabha and Kattamodan, with less leaf rolling, better drought recovery ability as well as relative water content, increased membrane stability index, osmolyte accumulation, and antioxidant enzyme activities pointed towards their degree of tolerance to drought stress. The positive adaptive responses of these rice varieties towards drought stress can be used in the genetic improvement of rice drought resistance breeding program.

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).

In-vitro Androgenesis in Rice: Advantages, Constraints and Future Prospects

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Rukmini Mishra

2016-03-01

Full Text Available In vitro androgenesis is an important component of plant biotechnology when the pollen grains are forced to switch from their normal pollen developmental pathway towards an embryogenic route. Haploid and doubled haploid produced through androgenesis have long been recognized as a valuable tool in plant breeding as it can shorten the breeding cycle, fix agronomic characters in homozygous state and enhance the selection efficiency of useful recessive agronomic traits. Recently, doubled haploids have been largely recognized as an important component of crop improvement through genome mapping, quantitative trait locus analysis, and genetic mutation, and as targets for genetic transformation programs. Thus, this review is focused mainly on various facets of doubled haploid in the chief staple food crop rice and sights its recent applications in plant breeding, genetics and genomics.

Inheritance patterns and identification of microsatellite markers linked to the rice blast resistance in BC2F1 population of rice breeding

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Gous Miah

2015-03-01

Full Text Available The BC2F1 population was derived from a cross between rice variety, MR219 (susceptible to blast and Pongsu Seribu 1 (resistant to blast. The objectives of this research were to know the inheritance pattern of blast resistance and to identify the linked markers associated with blast resistance in BC2F1 population. Sixteen microsatellite markers were found as polymorphic between the parents related to blast resistant genes (Pi-genes. Among the selected blast resistant linked markers, two markers RM6836 and RM8225 showed expected testcross ratio (1:1 for single-gene model in the BC2F1 population with the association between resistant and susceptible progeny. A total of 333-BC2F1 plants were challenged with the most virulent pathotype P7.2 of Magnaporthe oryzae. Chi-square (χ2 analysis for phenotypic segregation in single-gene model showed goodness of fit (P = 0.4463 to the expected segregation ratio (1:1. In marker segregation analysis, two polymorphic markers (RM6836 and RM8225 clearly showed goodness of fit to the expected segregation testcross ratio (1:1 for the single-gene model. The marker RM8225 and RM6836 showed significant R2 values higher than 10 for the trait of the blast lesions degree (BLD. The positions of RM6836 and RM8225 markers on rice chromosome 6 and the distance between these two markers is 0.2 cM. We conclude that single dominant gene control the blast resistance in Pongsu Seribu 1 located on chromosome 6, which is linked to RM8225 and RM6836 microsatellite markers. This information could be useful in marker-assisted selection for blast resistance in rice breeding involving Pongsu Seribu 1.

Identification of Heading Date Six (Hd6 Gene Derived from Rice Mutant Varieties

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Aryanti Aryanti

2017-04-01

Full Text Available Genes which were associated with flowering time to indicate the early maturity is known as heading date (Hd. Heading date six (Hd6 gene was identified from rice mutant varieties were Atomita 2, Atomita 3, Atomita 4, Bestari, Cilosari, Diah Suci, Sidenuk, Kahayan, Mayang, Meraoke, Mira-1, Pandan Putri, Superwin, Suluttan Unsrat 1, Suluttan Unsrat 2, Winongo, Woyla, Yuwono, while the rice var. Nipponbare was used as a positive control. All of rice mutant varieties derived from mutation induction by the dose of 0.2 kGy. The aim of this experiment was to find out the data base of mutant varieties which could be used as parent material with earlier maturity trait genetically. To obtain the DNA of plants, young leaves of each variety were extracted by liquid nitrogen, and then lysis and extracted by Kit Plant Genomic DNA. The amplification of DNA with 7 primers of Hd6 conducted of 40 cycles by PCR and were continues to separated by 1 % agarose. The results were shown that the rice Mira-1 and Bestari varieties obtained from mutation of Cisantana highly different from one to another on 7 primers of Hd6 used. Mayang variety from mutation of cross breeding between Cilosari and IR64, Pandan putri from Pandan wangi and Woyla from mutation of cross breeding from Atomita 2 and IR64 were highly different with those of their parents. Identification of Hd6 gene on Sidenuk variety was shown the same bands pattern with Nipponbare as control positive toward all primers used, this variety would be better for earlier maturity parent material compared to others. The information could be useful for breeding programs aiming to develop early maturing widely adaptive and high yielding rice cultivars.

Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

International Nuclear Information System (INIS)

Mahadtanapuk, S.; Teraarusiri, W.; Phanchaisri, B.; Yu, L.D.; Anuntalabhochai, S.

2013-01-01

Highlights: •N-ion beam bombarded Thai jasmine rice seeds to induce mutation. •Mutants with blast-disease resistance and high yield were screened. •Gene involved in the blast-disease resistance was analyzed. •The gene responsible for the resistance was linked to Spotted leaf protein 11. -- Abstract: Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60–80 keV to a beam fluence range of 2 × 10 16 –2 × 10 17 ions/cm 2 . The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 10 6 spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11)

Association between sequence variants in panicle development genes and the number of spikelets per panicle in rice.

Science.gov (United States)

Jang, Su; Lee, Yunjoo; Lee, Gileung; Seo, Jeonghwan; Lee, Dongryung; Yu, Yoye; Chin, Joong Hyoun; Koh, Hee-Jong

2018-01-15

Balancing panicle-related traits such as panicle length and the numbers of primary and secondary branches per panicle, is key to improving the number of spikelets per panicle in rice. Identifying genetic information contributes to a broader understanding of the roles of gene and provides candidate alleles for use as DNA markers. Discovering relations between panicle-related traits and sequence variants allows opportunity for molecular application in rice breeding to improve the number of spikelets per panicle. In total, 142 polymorphic sites, which constructed 58 haplotypes, were detected in coding regions of ten panicle development gene and 35 sequence variants in six genes were significantly associated with panicle-related traits. Rice cultivars were clustered according to their sequence variant profiles. One of the four resultant clusters, which contained only indica and tong-il varieties, exhibited the largest average number of favorable alleles and highest average number of spikelets per panicle, suggesting that the favorable allele combination found in this cluster was beneficial in increasing the number of spikelets per panicle. Favorable alleles identified in this study can be used to develop functional markers for rice breeding programs. Furthermore, stacking several favorable alleles has the potential to substantially improve the number of spikelets per panicle in rice.

The use of induced mutation combined with crossing in high quality rice breeding

International Nuclear Information System (INIS)

Do Huu At; Bui Huy Thuy; Nguyen Van Bich; Tran Duy Quy; Nguyen Minh Cong

2001-01-01

The high quality rice varieties: Tam thom mutant rice Var., DT17 rice Var, DT21 glutinous rice Var were formed by induced mutation combined with crossing. Tam thom mutant rice Var. lost photosensitivity, could be planted 2 crops/year. DT17 rice Var with high yielding capacity, suitable for growth on lowland in summer crop, is replacing step-by-step Moctuyen rice Var. in North Vietnam. DT21 glutinous rice Var. could be planted 2 crops/year and had short growth duration, average yield was 4.0-4.5 tons/ha. These three ones had good quality, soft and scent cooked rice, suitable for customers and export requirements. Tam thom mutant rice Var. DT17 rice Var., DT21 and glutinous rice Var. were adopted for regional production by Ministry of Agriculture and Rural Development and allowed to be in trial production. (author)

The use of induced mutation combined with crossing in high quality rice breeding

Energy Technology Data Exchange (ETDEWEB)

Do Huu At; Bui Huy Thuy; Nguyen Van Bich; Tran Duy Quy [Agricultural Genetics Institute, Division of Genetics and Hybrid Rice Technology, Hanoi (Viet Nam); Nguyen Minh Cong [Hanoi No. 1 Teacher Training Univ., Department of Genetics (Viet Nam)

2001-03-01

The high quality rice varieties: Tam thom mutant rice Var., DT17 rice Var, DT21 glutinous rice Var were formed by induced mutation combined with crossing. Tam thom mutant rice Var. lost photosensitivity, could be planted 2 crops/year. DT17 rice Var with high yielding capacity, suitable for growth on lowland in summer crop, is replacing step-by-step Moctuyen rice Var. in North Vietnam. DT21 glutinous rice Var. could be planted 2 crops/year and had short growth duration, average yield was 4.0-4.5 tons/ha. These three ones had good quality, soft and scent cooked rice, suitable for customers and export requirements. Tam thom mutant rice Var. DT17 rice Var., DT21 and glutinous rice Var. were adopted for regional production by Ministry of Agriculture and Rural Development and allowed to be in trial production. (author)

Optimisation of selective breeding program for Nile tilapia (Oreochromis niloticus)

NARCIS (Netherlands)

Trong, T.Q.

2013-01-01

The aim of this thesis was to optimise the selective breeding program for Nile tilapia in the Mekong Delta region of Vietnam. Two breeding schemes, the “classic” BLUP scheme following the GIFT method (with pair mating) and a rotational mating scheme with own performance selection and

Breeding program for indigenous chicken in Kenya

NARCIS (Netherlands)

Ngeno, K.

2015-01-01

Abstract

Ngeno, K. (2015). Breeding program for indigenous chicken in Kenya. Analysis of diversity in indigenous chicken populations. PhD thesis, Wageningen University, the Netherlands

The objective of this research was to generate knowledge required for the

Physical mapping of Bph3, a brown planthopper resistance locus in rice

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Jirapong Jairin

2007-09-01

Full Text Available Resistance to brown planthopper (BPH, a destructive phloem feeding insect pest, is an important objective in rice breeding programs in Thailand. The broad-spectrum resistance gene Bph3 is one of the major BPH resistance genes identified so far in cultivated rice and has been widely used in rice improvement programs. This resistance gene has been identified and mapped on the short arm of chromosome 6. In this study, physical mapping of Bph3 was performed using a BC3F3 population derived from a cross between Rathu Heenati and KDML105. Recombinant BC3F3 individuals with the Bph3 genotype were determined by phenotypic evaluation using modified mass tiller screening at the vegetative stage of rice plants. The recombination events surrounding the Bph3 locus were used to identify the co-segregate markers. According to the genome sequence of Nipponbare, the Bph3 locus was finally localized approximately in a 190 kb interval flanked by markers RM19291 and RM8072, which contain twenty-two putative genes. Additional phenotypic experiment revealed that the resistance in Rathu Heenati was decreased by increasing nitrogen content in rice plants through remobilization of nitrogen. This phenomenon should be helpful for identifying the Bph3 gene.

Strategies for use of reproductive technologies in genomic dairy cattle breeding programs

DEFF Research Database (Denmark)

Thomasen, Jørn Rind; Sørensen, Anders Christian

A simulation study was performed for testing the effect of using reproductive technologies in a genomic dairy cattle young bull breeding scheme. The breeding scheme parameters: 1) number of donors, 2) number of progeny per donor, 3) age of the donor, 4) number of sires, and 5) reliability...... of genomic breeding values. The breeding schemes were evaluated according to genetic gain and rate of inbreeding. The relative gain by use of reproductive technologies is 11 to 84 percent points depending on the choice of other breeding scheme parameters. A large donor program with high selection intensity...... of sires provides the highest genetic gain. A relatively higher genetic gain is obtained for higher reliability of GEBV. Extending the donor program and number of selected bulls has a major effect of reducing the rate of inbreeding without compromising genetic gain....

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.

Mosquitoes and other aquatic insects in fallow field biotopes and rice paddy fields.

Science.gov (United States)

Ohba, S Y; Matsuo, T; Takagi, M

2013-03-01

Fallow field biotopes that develop from abandoned rice fields are man-made wetlands that provide new habitats for various aquatic animals. Although consideration of such biotopes generally focuses on their positive aspects, this study evaluated the negative aspects of establishing fallow field biotopes with regard to mosquito breeding sites. To determine whether fallow field biotopes become breeding habitats for vector mosquitoes, we evaluated mosquito fauna in fallow field biotopes and adjacent rice fields. We found larvae of Anopheles lesteri, Anopheles sinensis and Culex tritaeniorhynchus (all: Diptera: Culicidae) in the biotopes. Although abundances of mosquito larvae in the biotopes and rice fields were statistically similar, mosquito abundances in rice fields increased dramatically in August when the water level reduced after the rainy season. The abundance and variety of the mosquitoes' natural predators were greater in biotopes than in rice fields because the former are a permanent and stable aquatic environment. A generalized linear mixed model showed a negative effect of predator diversity on mosquito larvae abundance in both habitats. Although fallow field biotopes become breeding habitats for vector mosquitoes, establishing biotopes from fallow fields in order to protect various aquatic animals, including mosquito insect predators, may help to control mosquito breeding. © 2012 The Royal Entomological Society.

RPAN: rice pan-genome browser for ∼3000 rice genomes.

Science.gov (United States)

Sun, Chen; Hu, Zhiqiang; Zheng, Tianqing; Lu, Kuangchen; Zhao, Yue; Wang, Wensheng; Shi, Jianxin; Wang, Chunchao; Lu, Jinyuan; Zhang, Dabing; Li, Zhikang; Wei, Chaochun

2017-01-25

A pan-genome is the union of the gene sets of all the individuals of a clade or a species and it provides a new dimension of genome complexity with the presence/absence variations (PAVs) of genes among these genomes. With the progress of sequencing technologies, pan-genome study is becoming affordable for eukaryotes with large-sized genomes. The Asian cultivated rice, Oryza sativa L., is one of the major food sources for the world and a model organism in plant biology. Recently, the 3000 Rice Genome Project (3K RGP) sequenced more than 3000 rice genomes with a mean sequencing depth of 14.3×, which provided a tremendous resource for rice research. In this paper, we present a genome browser, Rice Pan-genome Browser (RPAN), as a tool to search and visualize the rice pan-genome derived from 3K RGP. RPAN contains a database of the basic information of 3010 rice accessions, including genomic sequences, gene annotations, PAV information and gene expression data of the rice pan-genome. At least 12 000 novel genes absent in the reference genome were included. RPAN also provides multiple search and visualization functions. RPAN can be a rich resource for rice biology and rice breeding. It is available at http://cgm.sjtu.edu.cn/3kricedb/ or http://www.rmbreeding.cn/pan3k. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Fruit Phenolic Profiling: A New Selection Criterion in Olive Breeding Programs.

Science.gov (United States)

Pérez, Ana G; León, Lorenzo; Sanz, Carlos; de la Rosa, Raúl

2018-01-01

Olive growing is mainly based on traditional varieties selected by the growers across the centuries. The few attempts so far reported to obtain new varieties by systematic breeding have been mainly focused on improving the olive adaptation to different growing systems, the productivity and the oil content. However, the improvement of oil quality has rarely been considered as selection criterion and only in the latter stages of the breeding programs. Due to their health promoting and organoleptic properties, phenolic compounds are one of the most important quality markers for Virgin olive oil (VOO) although they are not commonly used as quality traits in olive breeding programs. This is mainly due to the difficulties for evaluating oil phenolic composition in large number of samples and the limited knowledge on the genetic and environmental factors that may influence phenolic composition. In the present work, we propose a high throughput methodology to include the phenolic composition as a selection criterion in olive breeding programs. For that purpose, the phenolic profile has been determined in fruits and oils of several breeding selections and two varieties ("Picual" and "Arbequina") used as control. The effect of three different environments, typical for olive growing in Andalusia, Southern Spain, was also evaluated. A high genetic effect was observed on both fruit and oil phenolic profile. In particular, the breeding selection UCI2-68 showed an optimum phenolic profile, which sums up to a good agronomic performance previously reported. A high correlation was found between fruit and oil total phenolic content as well as some individual phenols from the two different matrices. The environmental effect on phenolic compounds was also significant in both fruit and oil, although the low genotype × environment interaction allowed similar ranking of genotypes on the different environments. In summary, the high genotypic variance and the simplified procedure of the

Fruit Phenolic Profiling: A New Selection Criterion in Olive Breeding Programs

Directory of Open Access Journals (Sweden)

Ana G. Pérez

2018-02-01

Full Text Available Olive growing is mainly based on traditional varieties selected by the growers across the centuries. The few attempts so far reported to obtain new varieties by systematic breeding have been mainly focused on improving the olive adaptation to different growing systems, the productivity and the oil content. However, the improvement of oil quality has rarely been considered as selection criterion and only in the latter stages of the breeding programs. Due to their health promoting and organoleptic properties, phenolic compounds are one of the most important quality markers for Virgin olive oil (VOO although they are not commonly used as quality traits in olive breeding programs. This is mainly due to the difficulties for evaluating oil phenolic composition in large number of samples and the limited knowledge on the genetic and environmental factors that may influence phenolic composition. In the present work, we propose a high throughput methodology to include the phenolic composition as a selection criterion in olive breeding programs. For that purpose, the phenolic profile has been determined in fruits and oils of several breeding selections and two varieties (“Picual” and “Arbequina” used as control. The effect of three different environments, typical for olive growing in Andalusia, Southern Spain, was also evaluated. A high genetic effect was observed on both fruit and oil phenolic profile. In particular, the breeding selection UCI2-68 showed an optimum phenolic profile, which sums up to a good agronomic performance previously reported. A high correlation was found between fruit and oil total phenolic content as well as some individual phenols from the two different matrices. The environmental effect on phenolic compounds was also significant in both fruit and oil, although the low genotype × environment interaction allowed similar ranking of genotypes on the different environments. In summary, the high genotypic variance and the

Food Crops Breeding in Sri Lanka - Achievements and challenges

Energy Technology Data Exchange (ETDEWEB)

Jayawardena, S D.L.; Peiris, R [Central Agricultural Research Institute, Gannoruwa, Peradeniya (Sierra Leone)

1988-12-31

Since Rice is the staple food in Sri Lanka strong emphasis has been given for the improvement of Rice in Sri Lanka. Over the last three decades 36 high yielding rice varieties have been developed. The present yield potential of Sri Lanka`s best varieties have been recorded to be be around 10 mt/ha. At present more than 90% of the total paddy extent is grown with modern high yielding rice varieties and as a result the national paddy production has increased from 1.8 mt/ha to 3.5 mt/ha. Induced mutations is used in plant breeding. Use of radiation to produce haploids and for production of transitory sexuality in apomicts have been done. Under the coarse grains and millet varietal program, maize have recorded increasing attention owing to the fact that is is used for human consumption and as feed grain for poultry. Promising varieties of Soya bean, cowpea, mung bean, black gram and ground nut have been recommended for cultivation. Research attention has also been directed towards Root and Tuber crops which have great potential in providong food for the rapidly increasing population in Sri Lanka. Potato is the most important and popular tuber crop. A number of improved varieties with respect to a number of local fruit crops such as banana, sweet orange, lemonime, avocado, pineapple, rambutan, grapes.have been introduced. New improved varieties of indigenous vegetables such as tomato, brinjal etc. have been produced. Chillies and onions with desirable qualities also have been identified. Mutation breeding provides a novel approach to the plant breeders for raising the productivity of crop plants, thus complementing conventional methods. Any way the use of induced mutations in crop improvement has not been properly exploited in Sri Lanka as yet.

Food Crops Breeding in Sri Lanka - Achievements and challenges

International Nuclear Information System (INIS)

Jayawardena, S.D.L.; Peiris, R.

1988-01-01

Since Rice is the staple food in Sri Lanka strong emphasis has been given for the improvement of Rice in Sri Lanka. Over the last three decades 36 high yielding rice varieties have been developed. The present yield potential of Sri Lanka's best varieties have been recorded to be be around 10 mt/ha. At present more than 90% of the total paddy extent is grown with modern high yielding rice varieties and as a result the national paddy production has increased from 1.8 mt/ha to 3.5 mt/ha. Induced mutations is used in plant breeding. Use of radiation to produce haploids and for production of transitory sexuality in apomicts have been done. Under the coarse grains and millet varietal program, maize have recorded increasing attention owing to the fact that is is used for human consumption and as feed grain for poultry. Promising varieties of Soya bean, cowpea, mung bean, black gram and ground nut have been recommended for cultivation. Research attention has also been directed towards Root and Tuber crops which have great potential in providong food for the rapidly increasing population in Sri Lanka. Potato is the most important and popular tuber crop. A number of improved varieties with respect to a number of local fruit crops such as banana, sweet orange, lemonime, avocado, pineapple, rambutan, grapes.have been introduced. New improved varieties of indigenous vegetables such as tomato, brinjal etc. have been produced. Chillies and onions with desirable qualities also have been identified. Mutation breeding provides a novel approach to the plant breeders for raising the productivity of crop plants, thus complementing conventional methods. Any way the use of induced mutations in crop improvement has not been properly exploited in Sri Lanka as yet

Problems Analysis on Increasing Rice Production Through Food Estate Program in Bulungan Regency, North Kalimantan

Science.gov (United States)

Setyo, P.; Elly, J.

2018-05-01

To increase rice production in the Province of North Kalimantan, the provincial government has launched a Food Estate Program. The program is also a central government program in relation to government policies on food security. One of the food estate development areas is the Delta Kayan Food Estate of 50,000 hectares in Bulungan Regency, where about 30,000 hectares area is a tidal land with a very fertile alluvial soil type. This policy study aims to identify and analyze problems of increasing rice production through food estate development in North Kalimantan Province and formulate priority programs as recommendations for policy making in increasing rice production. The study has identified a number of problems of increasing rice production, such as land tenure, land suitability, water system, infrastructure, accessibility of production factors, institutional, and capacity of human resources. The Analytic Hierarchy Process was applied to develop priority programs, resulting in the three most important programs being water management, improving access to production factors, and improving the capacity of human resources. Action plans related to priority programs have also been identified.

Research Advances in High-Yielding Cultivation and Physiology of Super Rice

Directory of Open Access Journals (Sweden)

Jing FU

2012-09-01

Full Text Available In 1996, China launched a program to breed super rice or super hybrid rice by combining intersubspecific heterosis with ideal plant types. Today, approximately 80 super rice varieties have been released and some of them show high grain yields of 12–21 t/hm2 in field experiments. The main reasons for the high yields of super rice varieties, compared with those of conventional varieties, can be summarized as follows: more spikelets per panicle and larger sink size (number of spikelets per square meter; larger leaf area index, longer duration of green leaf, greater photosynthetic rate, higher lodging resistance, greater dry matter accumulation before the heading stage, greater remobilization of pre-stored carbohydrates from stems and leaves to grains during the grain-filling period; and larger root system and greater root activity. However, there are two main problems in super rice production: poor grain-filling of the later-flowering inferior spikelets (in contrast to earlier-flowering superior spikelets, and low and unstable seed-setting rate. Here, we review recent research advances in the crop physiology of super rice, focusing on biological features, formation of yield components, and population quality. Finally, we suggest further research on crop physiology of super rice.

Engineering the lodging resistance mechanism of post-Green Revolution rice to meet future demands.

Science.gov (United States)

Hirano, Ko; Ordonio, Reynante Lacsamana; Matsuoka, Makoto

2017-01-01

Traditional breeding for high-yielding rice has been dependent on the widespread cultivation of gibberellin (GA)-deficient semi-dwarf varieties. Dwarfism lowers the "center of gravity" of the plant body, which increases resistance against lodging and enables plants to support high grain yield. Although this approach was successful in latter half of the 20th century in rice and wheat breeding, this may no longer be enough to sustain rice with even higher yields. This is because relying solely on the semi-dwarf trait is subject to certain limitations, making it necessary to use other important traits to reinforce it. In this review, we present an alternative approach to increase lodging resistance by improving the quality of the culm by identifying genes related to culm quality and introducing these genes into high-yielding rice cultivars through molecular breeding technique.

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

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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.

Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

Energy Technology Data Exchange (ETDEWEB)

Mahadtanapuk, S. [School of Agriculture and Natural Resources, University of Phayao, Phayao 56000 (Thailand); Teraarusiri, W. [Central Laboratory, University of Phayao, Phayao 56000 (Thailand); Phanchaisri, B. [Science and Technology Research Institute, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@frnf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Anuntalabhochai, S., E-mail: burinka@hotmail.com [Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

2013-07-15

Highlights: •N-ion beam bombarded Thai jasmine rice seeds to induce mutation. •Mutants with blast-disease resistance and high yield were screened. •Gene involved in the blast-disease resistance was analyzed. •The gene responsible for the resistance was linked to Spotted leaf protein 11. -- Abstract: Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60–80 keV to a beam fluence range of 2 × 10{sup 16}–2 × 10{sup 17} ions/cm{sup 2}. The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 10{sup 6} spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11)

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...

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.

Simulated selection responses for breeding programs including resistance and resilience to parasites in Creole goats.

Science.gov (United States)

Gunia, M; Phocas, F; Gourdine, J-L; Bijma, P; Mandonnet, N

2013-02-01

The Creole goat is a local breed used for meat production in Guadeloupe (French West Indies). As in other tropical countries, improvement of parasite resistance is needed. In this study, we compared predicted selection responses for alternative breeding programs with or without parasite resistance and resilience traits. The overall breeding goal included traits for production, reproduction, and parasite resilience and resistance to ensure a balanced selection outcome. The production traits were BW and dressing percentage (DP). The reproduction trait was fertility (FER), which was the number of doe kiddings per mating. The resistance trait was worm fecal egg count (FEC), which is a measurement of the number of gastro-intestinal parasite eggs found in the feces. The resilience trait was the packed cell volume (PCV), which is a measurement of the volume of red blood cells in the blood. Dressing percentage, BW, and FEC were measured at 11 mo of age, which is the mating or selling age. Fertility and PCV were measured on females at each kidding period. The breeding program accounting for the overall breeding goal and a selection index including all traits gave annual selection responses of 800 g for BW, 3.75% for FER, 0.08% for DP, -0.005 ln(eggs/g) for FEC, and 0.28% for PCV. The expected selection responses for BW and DP in this breeding program were reduced by 2% and 6%, respectively, compared with a breeding program not accounting for FEC and PCV. The overall breeding program, proposed for the Creole breed, offers the best breeding strategy in terms of expected selection responses, making it possible to improve all traits together. It offers a good balance between production and adaptation traits and may present some interest for the selection of other goat breeds in the tropics.

Analysis of Lysophospholipid Content in Low Phytate Rice Mutants.

Science.gov (United States)

Tong, Chuan; Chen, Yaling; Tan, Yuanyuan; Liu, Lei; Waters, Daniel L E; Rose, Terry J; Shu, Qingyao; Bao, Jinsong

2017-07-05

As a fundamental component of nucleic acids, phospholipids, and adenosine triphosphate, phosphorus (P) is critical to all life forms, however, the molecular mechanism of P translocation and distribution in rice grains are still not understood. Here, with the use of five different low phytic acid (lpa) rice mutants, the redistribution in the main P-containing compounds in rice grain, phytic acid (PA), lysophospholipid (LPL), and inorganic P (Pi), was investigated. The lpa mutants showed a significant decrease in PA and phytate-phosphorus (PA-P) concentration with a concomitant increase in Pi concentration. Moreover, defects in the OsST and OsMIK genes result in a great reduction of specific LPL components and LPL-phosphorus (LPL-P) contents in rice grain. In contrast, defective OsMRP5 and Os2-PGK genes led to a significant increase in individual LPL components. The effect of the Os2-PGK gene on the LPL accumulation was validated using breeding lines derived from a cross between KBNT-lpa (Os2-PGK mutation) and Jiahe218. This study demonstrates that these rice lpa mutants lead to the redistribution of Pi in endosperm and modify LPL biosynthesis. Increase LPLs in the endosperm in the lpa mutants may have practical applications in rice breeding to produce "healthier" rice.

Biotechnological approach in crop improvement by mutation breeding in Indonesia

Energy Technology Data Exchange (ETDEWEB)

Soeranto, H.; Sobrizal; Sutarto, Ismiyati; Manurung, Simon; Mastrizal [National Nuclear Energy Agency, Center for Research and Development of Isotope and Radiation Technology, Jakarta (Indonesia)

2002-02-01

Mutation breeding has become a proven method of improving crop varieties. Most research on plant mutation breeding in Indonesia is carried out at the Center for Research and Development of Isotope and Radiation Technology, National Nuclear Energy Agency (BATAN). Nowadays, a biotechnological approach has been incorporated in some mutation breeding researches in order to improve crop cultivars. This approach is simply based on cellular totipotency, or the ability to regenerate whole, flowering plants from isolated organs, pieces of tissue, individual cells, and protoplasts. Tissue culture technique has bee extensively used for micro propagation of disease-free plants. Other usage of this technique involves in various steps of the breeding process such as germplasm preservation, clonal propagation, and distant hybridization. Mutation breeding combined with tissue culture technique has made a significant contribution in inducing plant genetic variation, by improving selection technology, and by accelerating breeding time as for that by using anther or pollen culture. In Indonesia, research on mutation breeding combined with tissue culture techniques has been practiced in different crop species including rice, ginger, banana, sorghum etc. Specially in rice, a research on identification of DNA markers linked to blast disease resistance is now still progressing. A compiled report from some research activities is presented in this paper. (author)

Genetic and molecular characterization of photoperiod and thermo-sensitive male sterility in rice.

Science.gov (United States)

Fan, Yourong; Zhang, Qifa

2018-03-01

A review on photoperiod and temperature-sensitive genic male sterility in rice. Male sterility in plants, facilitating the development of hybrid crops, has made great contribution to crop productivity worldwide. Environment-sensitive genic male sterility (EGMS), including photoperiod-sensitive genic male sterility (PGMS) and temperature-sensitive genic male sterility (TGMS), has provided a special class of germplasms for the breeding of "two-line" hybrids in several crops. In rice, the finding of the PGMS NK58S mutant in 1973 started the journey of research and breeding of two-line hybrids. Genetic and molecular characterization of these germplasms demonstrated diverse genes and molecular mechanisms of male sterility regulation. Two loci identified from NK58S, PMS1 and PMS3, both encode long noncoding RNAs. A major TGMS locus, TMS5, found in the TGMS line Annong S-1, encodes an RNase Z. A reverse PGMS mutant carbon starved anther encodes an R2R3 MYB transcription factor. Breeding efforts in the last three decades have resulted in hundreds of EGMS lines and two-line hybrids released to rice production, which have greatly elevated the yield potential and grain quality of rice varieties. The enhanced molecular understanding will offer new strategies for the development of EGMS lines thus further improving two-line hybrid breeding of rice as well as other crops.

Tillering and panicle branching genes in rice.

Science.gov (United States)

Liang, Wei-hong; Shang, Fei; Lin, Qun-ting; Lou, Chen; Zhang, Jing

2014-03-01

Rice (Oryza sativa L.) is one of the most important staple food crops in the world, and rice tillering and panicle branching are important traits determining grain yield. Since the gene MONOCULM 1 (MOC 1) was first characterized as a key regulator in controlling rice tillering and branching, great progress has been achieved in identifying important genes associated with grain yield, elucidating the genetic basis of yield-related traits. Some of these important genes were shown to be applicable for molecular breeding of high-yielding rice. This review focuses on recent advances, with emphasis on rice tillering and panicle branching genes, and their regulatory networks. Copyright © 2013 Elsevier B.V. All rights reserved.

Genomic selection needs to be carefully assessed to meet specific requirements in livestock breeding programs.

Science.gov (United States)

Jonas, Elisabeth; de Koning, Dirk-Jan

2015-01-01

Genomic selection is a promising development in agriculture, aiming improved production by exploiting molecular genetic markers to design novel breeding programs and to develop new markers-based models for genetic evaluation. It opens opportunities for research, as novel algorithms and lab methodologies are developed. Genomic selection can be applied in many breeds and species. Further research on the implementation of genomic selection (GS) in breeding programs is highly desirable not only for the common good, but also the private sector (breeding companies). It has been projected that this approach will improve selection routines, especially in species with long reproduction cycles, late or sex-limited or expensive trait recording and for complex traits. The task of integrating GS into existing breeding programs is, however, not straightforward. Despite successful integration into breeding programs for dairy cattle, it has yet to be shown how much emphasis can be given to the genomic information and how much additional phenotypic information is needed from new selection candidates. Genomic selection is already part of future planning in many breeding companies of pigs and beef cattle among others, but further research is needed to fully estimate how effective the use of genomic information will be for the prediction of the performance of future breeding stock. Genomic prediction of production in crossbreeding and across-breed schemes, costs and choice of individuals for genotyping are reasons for a reluctance to fully rely on genomic information for selection decisions. Breeding objectives are highly dependent on the industry and the additional gain when using genomic information has to be considered carefully. This review synthesizes some of the suggested approaches in selected livestock species including cattle, pig, chicken, and fish. It outlines tasks to help understanding possible consequences when applying genomic information in breeding scenarios.

Genomic selection needs to be carefully assessed to meet specific requirements in livestock breeding programs

Directory of Open Access Journals (Sweden)

Elisabeth eJonas

2015-02-01

Full Text Available Genomic selection is a promising development in agriculture, aiming improved production by exploiting molecular genetic markers to design novel breeding programs and to develop new markers-based models for genetic evaluation. It opens opportunities for research, as novel algorithms and lab methodologies are developed. Genomic selection can be applied in many breeds and species. Further research on the implementation of genomic selection in breeding programs is highly desirable not only for the common good, but also the private sector (breeding companies. It has been projected that this approach will improve selection routines, especially in species with long reproduction cycles, late or sex-limited or expensive trait recording and for complex traits. The task of integrating genomic selection into existing breeding programs is, however, not straightforward. Despite successful integration into breeding programs for dairy cattle, it has yet to be shown how much emphasis can be given to the genomic information and how much additional phenotypic information is needed from new selection candidates. Genomic selection is already part of future planning in many breeding companies of pigs and beef cattle among others, but further research is needed to fully estimate how effective the use of genomic information will be for the prediction of the performance of future breeding stock. Genomic prediction of production in crossbreeding and across-breed schemes, costs and choice of individuals for genotyping are reasons for a reluctance to fully rely on genomic information for selection decisions. Breeding objectives are highly dependent on the industry and the additional gain when using genomic information has to be considered carefully. This review synthesizes some of the suggested approaches in selected livestock species including cattle, pig, chicken and fish. It outlines tasks to help understanding possible consequences when applying genomic information in

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.

Global Information Resources on Rice for Research and Development

Directory of Open Access Journals (Sweden)

Shri RAM

2012-12-01

Full Text Available Various issues concerning the progress of rice research are related to ambiguous germplasm identification, difficulty in tracing pedigree information, and lack of integration between genetic resources, characterization, breeding, evaluation and utilization data. These issues are the constraints in developing knowledge-intensive crop improvement programs. The rapid growth, development and the global spread of modern information and communication technology allow quick adoption in fundamental research. Thus, there is a need to provide an opportunity for the establishment of services which describe the rice information for better accessibility to information resources used by researchers to enhance the competitiveness. This work reviews some of available resources on rice bioinformatics and their roles in elucidating and propagating biological and genomic information in rice research. These reviews will also enable stakeholders to understand and adopt the change in research and development and share knowledge with the global community of agricultural scientists. The establishment like International Rice Information System, Rice Genome Research Project and Integrated Rice Genome Explorer are major initiatives for the improvement of rice. Creation of databases for comparative studies of rice and other cereals are major steps in further improvement of genetic compositions. This paper will also highlight some of the initiatives and organizations working in the field of rice improvement and explore the availability of the various web resources for the purpose of research and development of rice. We are developing a meta web server for integration of online resources such as databases, web servers and journals in the area of bioinformatics. This integrated platform, with acronym iBIRA, is available online at ibiranet.in. The resources reviewed here are the excerpts from the resources integrated in iBIRA.

Breeding programs for the main economically important traits of zebu dairy cattle

Directory of Open Access Journals (Sweden)

Ariosto Ardila Silva

2010-06-01

Full Text Available In tropical regions, Gyr and Guzerat breeds (Bos indicus are most explored for dairy industry and are much more adapted to climate. Gyr and Guzerat are Zebu breeds very common in Brazil and they are being used to generate Bos taurus x Bos indicus crosses in order to combine good production, heat and parasite tolerance on the tropics. Breeding programs for the main economically important traits of Zebu dairy cattle have been recently introduced in Brazil and is based on the use of genetically superior sires in the herds. A major objective of QTL (Quantitative Trait Loci and candidate genes is to find genes and markers that can be implemented in breeding programs across marker assisted selection (MAS. In Zebu dairy cattle MAS could be used to pre-select young candidate bulls to progeny testing, thus increasing selection differentials, shortening generation interval and increasing genetic gain

Rice breeding with induced mutations in France

Energy Technology Data Exchange (ETDEWEB)

Marie, R [Station d' Amelioration des Plantes, Institut National de Recherches Agronomiques, Montpellier (France)

1970-03-01

Mutation experiments with rice at Montpellier yielded strains with improved lodging resistance, grain size, maturing time, milling quality and other characters. The general performance of these mutant strains was tested in field trials. Further mutagenic treatments were made to improve the high-yielding short grain varieties with regard to grain quality and seed dormancy. (author)

BREED: a CDC-7600 computer program for the automation of breeder reactor design analysis (LWBR Development Program)

International Nuclear Information System (INIS)

Candelore, N.R.; Maher, C.M.

1985-03-01

BREED is an executive CDC-7600 program which was developed to facilitate the sequence of calculations and movement of data through a prescribed series of breeder reactor design computer programs in an uninterrupted single-job mode. It provides the capability to interface different application programs into a single computer run to provide a complete design function. The automation that can be achieved as a result of using BREED significantly reduces not only the time required for data preparation and hand transfer of data, but also the time required to complete an iteration of the total design effort. Data processing within a technical discipline and data transfer between technical disciplines can be accommodated. The input/output data processing is achieved with BREED by using a set of simple, easily understood user commands, usually short descriptive words, which the user inserts in his input deck. The input deck completely identifies and controls the calculational sequence needed to produce a desired end product. This report has been prepared to provide instructional material on the use of BREED and its user-oriented procedures to facilitate computer automation of design calculations

Laboratory Screening for Resistance in Rice to Rice Stem Borer Chilo Suppressalis Walker

International Nuclear Information System (INIS)

Singgih Sutrisno

2004-01-01

Rice stem borer Chilo suppressalis Walker is one of the major insect pests in rice in Indonesia. The use of insect pest resistant variety of rice is one of the effective techniques against pests. Breeding of resistance to insect pests rice crops often faced difficulties in obtaining a lot of insect amounts due to the unavailability of enough number insects pests in the field so that a laboratory bioassay is needed. In this experiments five rice varieties were used: a Pelita I/1, Atomita I, Cisadane, Cisanggarung, and IR 36. Rice seedling 7 days of age were put in 1 liter plastic vials for rice resistance test against the attack of insect pest C. suppressalis. The parameters observed were larval and pupal viability, pupal weight, and eggs production. The larval and pupal viability which were reared on of Pelita I/1 and Atomita I rice seedlings were 68.5 % - 55.5 % and 57.3 % - 46.7 % respectively. The respective lowest percentages were found in IR 36 which was about 41.3 % - 29.8 % .The experiment results on the parameters of pupal weight and egg production showed similar results to that on the parameters of larval and pupal viability. Rice variety of IR 36 showed more resistance to the other varieties, while Pelita I/1 and Atomita I showed the most susceptible to the attack of insect pest C. suppressalis. (author)

Rice varieties in relation to rice bread quality.

Science.gov (United States)

Han, Hye Min; Cho, Jun Hyeon; Kang, Hang Won; Koh, Bong Kyung

2012-05-01

It is difficult to predict rice bread quality only from the amylose content (AC) or dough characteristics of new lines produced by rice breeding programmes. This study investigated the AC relative to bread baking quality of rice varieties developed in Korea, and identified specific characteristics that contribute to rice bread quality. Manmibyeo, Jinsumi, Seolgaeng and Hanareumbyeo were classified as low AC, YR24088 Acp9, Suweon517, Chenmaai and Goamibyeo as intermediate AC and Milyang261 as high AC. Suweon517, Milyang261 and Manmibyeo had a high water absorption index (WAI), while Goamibyeo, YR24088 Acp9, Jinsumi, Seolgaeng, Hanareumbyeo and Chenmaai had a low WAI. The gelatinisation enthalpy of flour varied from 9.2 J g(-1) in Milyang261 to 14.8 J g(-1) in YR24088 Acp9. After 7 days of storage the rate of flour retrogradation and crumb firmness were weakly correlated, with the exception of Jinsumi. Bread volumes of Jinsumi, Chenmaai, YR24088 Acp9 and Goamibyeo were comparable to that of wheat flour, but the rest were unsuited to bread making because of their low volume and hard crumb texture. Based on volume, texture and crumb firmness ratio, Chenmaai and Goamibyeo were the most appropriate varieties for making bread. An intermediate AC and low WAI were the primary indicators of rice bread flour quality. Copyright © 2011 Society of Chemical Industry.

Genotypes analysis of ten genes related to eating quality of 22 Shanghai important rice varieties by molecular marker

Directory of Open Access Journals (Sweden)

XIE Mixue

2013-08-01

Full Text Available The improvement of rice eating quality is a very important direction of rice breeding.Clearing the different genotype of rice eating quality provides the basis for the parent selection on breeding good eating quality rice.Using molecular marker detection technology,genotypes of ten genes related to eating quality of 22 Shanghai important rice varieties,including conventional rice and hybrid parents were detected.The results showed that "Zixiangnuo 861" rice contained many poor genotypes which might affect rice eating quality.The genotypes of 3 male parents,"Xiangqin","R44" and "Fan14" for three kinds of hybrid rice,"Hannyouxiangqing","Qiuyoujinfeng" and "Huayou14",respectively,were not as good as their corresponding female parents,"HanfengA","JinfengA" and "Shen9A" and another conventional rice varieties.Wx polymorphism analysis showed that there were two glutinous rice,four soft rice japonica and 16 non-soft rice japonica."Baonong34","Jinfeng" and "Yinxiang18" had relatively better genotypes of the genes controlling eating quality among the 16 non-soft rice japonica.

Mutation breeding in rice in India

Energy Technology Data Exchange (ETDEWEB)

Swaminathan, M S; Siddiq, E A; Singh, C B; Pai, R A [Indian Agricultural Research Institute, New Delhi (India)

1970-03-01

Mutation research was continued in rice with the following aims; (a) to enhance the frequency and spectrum of mutations in indica and japonica rice varieties; (b) to change the grain quality of the japonica variety, Tainan-3, into the indica type; (c) to improve the grain quality of the indica variety, IR-8; (d) to increase the recombination frequency in japonica-indica hybrids. Both nitrosoguanidine and 5-MeV fast neutrons gave a high mutation frequency. The japonica variety was more sensitive to all mutagens than the indica types. Chemical mutagens had no particular advantage over ionizing radiations with reference to either mutation frequency or spectrum. Mutants with indica type of grain occurred readily in Tainan-3 in all treatments. Such mutants had a larger grain length/width ratio and were more resistant to alkali digestion. Fine grain types with better cooking quality occurred in the M{sub 2} populations of IR-8. These mutants are likely to render this high-yielding variety more popular. A wide range of chlorophyll and viable mutations occurred in IR-8 and Tainan-3. Some of these, like those involving dwarfing and slow senescence, are of economic interest, besides those affecting grain quality. Recombination frequency can be influenced in japonica x indica hybrids through the irradiation of F{sub 1} sporocytes. The precise influence varies with the stage at which the plant is irradiated, the dose given and the loci involved. (author)

Progress of mutation breeding in Thailand

Energy Technology Data Exchange (ETDEWEB)

Purivirojkul, Watchara; Vithayatherarat, Pradab [Pathumthani Rice Research Center (Thailand)

2001-03-01

The objectives in rice improvement in Thailand are to improve not only for high yielding and good grain quality but also for resistance to diseases and insects and tolerance to biotic stresses. Brief history of research and progress in rice mutation breeding in Thailand is presented. It includes the varieties of method such as using gamma rays, fast neutron and chemical mutagens, for example EMS (ethylmethane sulfonate) and EI (ethylene imine) for mutation works. Among all, improvements of Pathumthani 60 for short-statured plant type, RD23 for blast resistance, Basmati 370 for short-statured plant type, and Pra Doo Daeng for short-statured plant type and awnless grain are reported. To conclude, it is important to find the adequate doses of mutagen treatments that give maximum mutation frequencies, to know the optimal treatments or proper selection methods and to have well-defined objectives to create the success of mutation breeding. (S. Ohno)

Progress of mutation breeding in Thailand

International Nuclear Information System (INIS)

Purivirojkul, Watchara; Vithayatherarat, Pradab

2001-01-01

The objectives in rice improvement in Thailand are to improve not only for high yielding and good grain quality but also for resistance to diseases and insects and tolerance to biotic stresses. Brief history of research and progress in rice mutation breeding in Thailand is presented. It includes the varieties of method such as using gamma rays, fast neutron and chemical mutagens, for example EMS (ethylmethane sulfonate) and EI (ethylene imine) for mutation works. Among all, improvements of Pathumthani 60 for short-statured plant type, RD23 for blast resistance, Basmati 370 for short-statured plant type, and Pra Doo Daeng for short-statured plant type and awnless grain are reported. To conclude, it is important to find the adequate doses of mutagen treatments that give maximum mutation frequencies, to know the optimal treatments or proper selection methods and to have well-defined objectives to create the success of mutation breeding. (S. Ohno)

Effects of Soil Veterinary Antibiotics Pollution on Rice Growth

OpenAIRE

XU Qiu-tong; GU Guo-ping; ZHANG Ming-kui

2016-01-01

To understand the potential effect of soil veterinary antibiotics pollution on the growth of rice, a main food crop in China, oxytetracycline which was used widely in livestock and poultry breeding was selected to test the effects of different levels of soil antibiotics pollution on growth and yield of rice plant at both seedling and growth periods. Relationship between oxytetracycline accumulated in different organs of rice plant and oxytetracycline pollution levels in the soil was character...

Agronomic and molecular evaluation of induced mutant rice (oryza sativa l.) lines in Egypt

International Nuclear Information System (INIS)

Sshehzad, T.; Allah, A.; Aallah, E.A.; Ammar, M.H.; Abdelkhalik, A.H.

2011-01-01

The present study was conducted at the farm of the Rice Research and Training Center, Sakha, Kafr El-Sheikh, Egypt, during 2000-2007 rice sowing seasons. Five rice varieties viz., Giza 171, Giza 175, Giza 176, Giza 181 and GZ 1368 were the most widely grown Japonica and Indica types in Egypt during the last period, possesses at that time many positive agronomic characteristics including wide adaptability, high yield potential, tolerance to stresses and good eating quality. But with the passage of time it has lost its vigor. In Rice Research Program, Egypt, dry seeds of the above mentioned varieties were treated with different doses of gamma rays (100, 200, 300, 400, and 500 Gy) for raising M1 generation. M1 plants were established by transplanting in the year 2000 season. One hundred independent lines have been advanced to M5 generation enabling evaluation of quantitative traits by replicated trials and promising lines were selected and tested in multi-location trials as M6, M7 and M8 generations. Morphological variations at vegetative and reproductive stages including plant type and various physiological characters were observed in the five populations. The mutant lines characteristics consisted of better resistance to lodging, blast disease, high yield potential, as well as early maturity. Results from yield trials and molecular assessments indicated that the mutants differed genetically from their parents. So, these mutants could be used as a donor parents in rice breeding program and some of them can be recommended as new rice varieties suitable for rice belt in Egypt. (author)

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.

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.

IDENTIFICATION OF WIDE COMPATIBILITY VARIETIES IN SOME TROPICAL JAPONICA RICE

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A. Hairmansis

2013-07-01

Full Text Available The F1 hybrid sterility in indica/japonica crosses is the major barrier in developing hybrid rice varieties between these two diverse germplasm. The sterility problem in japonica/indica hybrids can be overcome by using wide compatibility genes. The objective of this study was to identify wide compatibility varieties (WCVs in some tropical japonica rice. Twenty five tropical japonica varieties as male parents were crossed with indica (IR64 and japonica (Akitakomachi testers as female parents. The crosses were planted following a randomized complete block design with three replications. Varieties having average spikelet fertility of more than 70% with both the indica and japonica testers were rated as WCVs. Result from this study showed that six tropical japonica varieties were classified as WCVs, i.e., Cabacu, Grogol, Kencana Bali, Klemas, Lampung Lawer, and Napa. Hybrid sterility is caused by partial sterility of male and female gametes. The WCVs from the present study can be used in hybrid rice breeding program to solve hybrid sterility in indica/japonica hybrids.

User Guide ECOREA-RICE (version 1.0). Program for assessing the transfer of radionuclides released accidentally onto flooded rice-fields

International Nuclear Information System (INIS)

Keum, Dong Kwon; Lee, Han Soo; Choi, Hei Hu; Kang, Hee Seok; Lee, Chang Woo

2004-05-01

The computer code ECOREA-RICE is a dynamic compartment model that is specially designed for estimating the transfer of radionuclides deposited onto flooded rice-fields after an accidental release. The model consists of six independent compartments including rice-body, grain, surface water, root-zone soil, fixed soil and deep soil, and takes into account the transfer processes including radioactive decay, percolation, leaching, shoot-base absorption, root-uptake, weathering, translocation, fixation in soil by adsorption and desorption, and soil-mixing by plowing. The rate of the change of radioactivity in compartments is expressed by a set of the first order ordinary differential equations, which are solved by the fourth order Runge-Kutta algorithm. Input to the program includes the deposition date, transplanting date, ear emergence date, harvest date, soil data, the biomass data of rice-plant, and rate constants associated with transfer processes. Output includes the list of input data, the activity of radionuclides in compartment, the rate constant, and the transfer factor of rice-body and grain with time

Plant Breeding and Genetics Newsletter, No. 38, January 2017

International Nuclear Information System (INIS)

2017-01-01

This year significant progress was made on the discovery of mutations using next generation sequencing for different crops, including rice and banana. Also, a program for the development of molecular markers for important traits has been initiated to translate the molecular knowledge on mutant traits into applications for plant breeding and to enable wider utilization of available useful mutant germplasm by Member States. A semi-dwarf mutant trait in sorghum was chosen in the pilot phase. In October 2016, a film crew visited the Agency’s Laboratories in Seibersdorf, including PBGL, in the context of a National Geographics project on the application of nuclear technologies to help address global challenges such as food, agriculture and climate change. In December 2016 a 22-minute documentary was aired on the National Geographics Channel in Belgium, the Netherlands and France highlighting the work at PBGL and the contribution of plant mutation breeding to food security and climate-smart agriculture.

Usefulness of portable near infrared spectroscopy in olive breeding programs

Energy Technology Data Exchange (ETDEWEB)

Leon-Moreno, L.

2012-11-01

The usefulness of portable near infrared (NIR) spectroscopy as a simple and efficient method to determine some of the main selection traits in olive breeding is evaluated in this work. Calibration models were developed and evaluated using partial least squares (PLS) regression from samples collected in different selection steps of the breeding work and under different experimental conditions. The results showed that accurate enough models (values of correlation between actual and predicted constituent higher than 0.9) were obtained for oil and moisture content in both cross validation and prediction results. Portable NIR spectroscopy could be used for selection of genotypes on the basis of these characters, providing similar ranking of genotypes than reference methods both in different selection steps of the breeding process (progenies and selection plots) and different experimental conditions (on-tree or under laboratory conditions). The advantages of this technique to improve the efficiency of the evaluation process in olive breeding programs are discussed. (Author) 21 refs.

Breeding programs for the main economically important traits of zebu dairy cattle

OpenAIRE

Ariosto Ardila Silva

2010-01-01

In tropical regions, Gyr and Guzerat breeds (Bos indicus) are most explored for dairy industry and are much more adapted to climate. Gyr and Guzerat are Zebu breeds very common in Brazil and they are being used to generate Bos taurus x Bos indicus crosses in order to combine good production, heat and parasite tolerance on the tropics. Breeding programs for the main economically important traits of Zebu dairy cattle have been recently introduced in Brazil and is based on the use of genetically...

Prospects for Genetic Improvement in Internal Nitrogen Use Efficiency in Rice

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Terry J. Rose

2017-10-01

Full Text Available While improving the efficiency at which rice plants take up fertiliser nitrogen (N will be critical for the sustainability of rice (Oryza sativa L. farming systems in future, improving the grain yield of rice produced per unit of N accumulated in aboveground plant material (agronomic N use efficiency; NUEagron through breeding may also be a viable means of improving the sustainability of rice cropping. Given that NUEagron (grain yield/total N uptake is a function of harvest index (HI; grain yield/crop biomass × crop biomass/total N uptake, and that improving HI is already the target of most breeding programs, and specific improvement in NUEagron can only really be achieved by increasing the crop biomass/N uptake. Since rice crops take up around 80% of total crop N prior to flowering, improving the biomass/N uptake (NUEveg prior to, or at, flowering may be the best means to improve the NUEagron. Ultimately, however, enhanced NUEagron may come at the expense of grain protein unless the N harvest index increases concurrently. We investigated the relationships between NUEagron, total N uptake, grain yield, grain N concentration (i.e., protein and N harvest index (NHI in 16 rice genotypes under optimal N conditions over two seasons to determine if scope exists to improve the NHI and/or grain protein, while maintaining or enhancing NUEagron in rice. Using data from these experiments and from an additional experiment with cv. IR64 under optimum conditions at an experimental farm to establish a benchmark for NUE parameters in high-input, high yielding conditions, we simulated theoretical potential improvements in NUEveg that could be achieved in both low and high-input scenarios by manipulating target NHIs and grain protein levels. Simulations suggested that scope exists to increase grain protein levels in low yielding scenarios with only modest (5–10% reductions in current NUEagron by increasing the current NHI from 0.6 to 0.8. Furthermore

Forty years of mutation breeding in Japan. Research and fruits

International Nuclear Information System (INIS)

Yamaguchi, Isao

2003-01-01

The radiation source used for breeding in the early years was mainly X rays. After the 2nd World War, gamma ray sources such as 60 Co and 137 Cs came to take a leading role in radiation breeding. The institute of Radiation Breeding (IRB) of the Ministry of Agriculture, Forestry and Fisheries (MAFF) was established on April 16, 1960. A gamma field with 2000Ci of a 60 Co source, the main irradiation facility of the IRB, was installed to study the genetically responses of crop plants to chronic exposures of ionizing radiation and their practical application to plant breeding. This paper consisted of 'forty years of research on radiobiology and mutation breeding in Japan', 'topics of mutation breeding research in IRB', 'outline of released varieties by mutation breeding' and 'future of mutation breeding'. The number of varieties released by the direct use of induced mutation in Japan amounts to 163 as of November 2001. Crops in which mutant varieties have been released range widely: rice and other cereals, industrial crops, forage crops, vegetables, ornamentals, mushrooms and fruit trees, the number of which reaches 48. The number of mutant varieties is highest (31) in chrysanthemum, followed by 22 in rice and 13 in soybean. By the indirect use of mutants, a total of 15 varieties of wheat, barley, soybean, mat rush and tomato have been registered by MAFF. Recent advances in biotechnological techniques have made it possible to determine DNA sequences of mutant genes. Accumulating information of DNA sequences and other molecular aspects of many mutant genes will throw light on the mechanisms of mutation induction and develop a new field of mutation breeding. (S.Y.)

Genomic Tools in Cowpea Breeding Programs: Status and Perspectives

Science.gov (United States)

Boukar, Ousmane; Fatokun, Christian A.; Huynh, Bao-Lam; Roberts, Philip A.; Close, Timothy J.

2016-01-01

Cowpea is one of the most important grain legumes in sub-Saharan Africa (SSA). It provides strong support to the livelihood of small-scale farmers through its contributions to their nutritional security, income generation and soil fertility enhancement. Worldwide about 6.5 million metric tons of cowpea are produced annually on about 14.5 million hectares. The low productivity of cowpea is attributable to numerous abiotic and biotic constraints. The abiotic stress factors comprise drought, low soil fertility, and heat while biotic constraints include insects, diseases, parasitic weeds, and nematodes. Cowpea farmers also have limited access to quality seeds of improved varieties for planting. Some progress has been made through conventional breeding at international and national research institutions in the last three decades. Cowpea improvement could also benefit from modern breeding methods based on molecular genetic tools. A number of advances in cowpea genetic linkage maps, and quantitative trait loci associated with some desirable traits such as resistance to Striga, Macrophomina, Fusarium wilt, bacterial blight, root-knot nematodes, aphids, and foliar thrips have been reported. An improved consensus genetic linkage map has been developed and used to identify QTLs of additional traits. In order to take advantage of these developments single nucleotide polymorphism (SNP) genotyping is being streamlined to establish an efficient workflow supported by genotyping support service (GSS)-client interactions. About 1100 SNPs mapped on the cowpea genome were converted by LGC Genomics to KASP assays. Several cowpea breeding programs have been exploiting these resources to implement molecular breeding, especially for MARS and MABC, to accelerate cowpea variety improvement. The combination of conventional breeding and molecular breeding strategies, with workflow managed through the CGIAR breeding management system (BMS), promises an increase in the number of improved

Genomic tools in cowpea breeding programs: status and perspectives

Directory of Open Access Journals (Sweden)

Ousmane eBoukar

2016-06-01

Full Text Available Cowpea is one of the most important grain legumes in sub-Saharan Africa (SSA. It provides strong support to the livelihood of small-scale farmers through its contributions to their nutritional security, income generation and soil fertility enhancement. Worldwide about 6.5 million metric tons of cowpea are produced annually on about 14.5 million hectares. The low productivity of cowpea is attributable to numerous abiotic and biotic constraints. The abiotic stress factors comprise drought, low soil fertility, and heat while biotic constraints include insects, diseases, parasitic weeds and nematodes. Cowpea farmers also have limited access to quality seeds of improved varieties for planting. Some progress has been made through conventional breeding at international and national research institutions in the last three decades. Cowpea improvement could also benefit from modern breeding methods based on molecular genetic tools. A number of advances in cowpea genetic linkage maps, and quantitative trait loci associated with some desirable traits such as resistance to Striga, Macrophomina, Fusarium wilt, bacterial blight, root-knot nematodes, aphids and foliar thrips have been reported. An improved consensus genetic linkage map has been developed and used to identify QTLs of additional traits. In order to take advantage of these developments single nucleotide polymorphism (SNP genotyping is being streamlined to establish an efficient workflow supported by genotyping support service (GSS-client interactions. About 1100 SNPs mapped on the cowpea genome were converted by LGC Genomics to KASP assays. Several cowpea breeding programs have been exploiting these resources to implement molecular breeding, especially for MARS and MABC, to accelerate cowpea variety improvement. The combination of conventional breeding and molecular breeding strategies, with workflow managed through the CGIAR breeding management system (BMS, promises an increase in the number of

Genomic selection accuracy using multi-family prediction models in a wheat breeding program

Science.gov (United States)

Genomic selection (GS) uses genome-wide molecular marker data to predict the genetic value of selection candidates in breeding programs. In plant breeding, the ability to produce large numbers of progeny per cross allows GS to be conducted within each family. However, this approach requires phenotyp...

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.

Optimisation of near-infrared reflectance model in measuring protein and amylose content of rice flour.

Science.gov (United States)

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

2014-01-01

Near-infrared reflectance spectroscopy (NIRS) has been used to predict the cooking quality parameters of rice, such as the protein (PC) and amylose content (AC). Using brown and milled flours from 519 rice samples representing a wide range of grain qualities, this study was to compare the calibration models generated by different mathematical, preprocessing treatments, and combinations of different regression algorithm. A modified partial least squares model (MPLS) with the mathematic treatment "2, 8, 8, 2" (2nd order derivative computed based on 8 data points, and 8 and 2 data points in the 1st and 2nd smoothing, respectively) and inverse multiplicative scattering correction preprocessing treatment was identified as the best model for simultaneously measurement of PC and AC in brown flours. MPLS/"2, 8, 8, 2"/detrend preprocessing was identified as the best model for milled flours. The results indicated that NIRS could be useful in estimation of PC and AC of breeding lines in early generations of the breeding programs, and for the purposes of quality control in the food industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

Improvement of traditional local rice varieties through induced mutations using nuclear techniques

International Nuclear Information System (INIS)

Pham Van Ro; Do Huu At

2001-01-01

'Improvement of local rice varieties for high yield, resistance to disease and insect pests (brown plant hopper and rice blast) and export quality through induced mutations for the Mekong Delta' started in 1993. After six years, it showed effecting on the field in the MD as well as at the south of Vietnam. TNDB-100 manifest very wide adaptation and yield stable variety. THDB is suitable for deepwater rice region, coastal area, where rice cultivation effected by acid sulphate and salinity conditions. Both varieties are good example for the method. Thank to good Co-operation from extension center from provinces, hundred classes of extension were organized to recommend to the farmers. And thank to the strongly supporting from IAEA so that nearly 400,000 ha of TNDB-100 occupied at the south of Vietnam as well as nearly 15,000 ha of THDB grown in the coastal as well as rainfed lowland rice areas at the South of Vietnam. To continue the rice improvement by this technique, seeds of six traditional local varieties were exposed under different dose of gamma rays to create new mutants. At present day hundred improved breeding lines were selected, a dozen of uniform lines were isolated and entranced the yield trail as well as regional testing program. From these improved varieties would be selected to contribute to the rice cultivation at the south of Vietnam in the next years. (author)

Improvement of traditional local rice varieties through induced mutations using nuclear techniques

Energy Technology Data Exchange (ETDEWEB)

Pham Van Ro; Do Huu At [Cuu Long Delta Rice Research Institute (Viet Nam)

2001-03-01

'Improvement of local rice varieties for high yield, resistance to disease and insect pests (brown plant hopper and rice blast) and export quality through induced mutations for the Mekong Delta' started in 1993. After six years, it showed effecting on the field in the MD as well as at the south of Vietnam. TNDB-100 manifest very wide adaptation and yield stable variety. THDB is suitable for deepwater rice region, coastal area, where rice cultivation effected by acid sulphate and salinity conditions. Both varieties are good example for the method. Thank to good Co-operation from extension center from provinces, hundred classes of extension were organized to recommend to the farmers. And thank to the strongly supporting from IAEA so that nearly 400,000 ha of TNDB-100 occupied at the south of Vietnam as well as nearly 15,000 ha of THDB grown in the coastal as well as rainfed lowland rice areas at the South of Vietnam. To continue the rice improvement by this technique, seeds of six traditional local varieties were exposed under different dose of gamma rays to create new mutants. At present day hundred improved breeding lines were selected, a dozen of uniform lines were isolated and entranced the yield trail as well as regional testing program. From these improved varieties would be selected to contribute to the rice cultivation at the south of Vietnam in the next years. (author)

Novel optimum contribution selection methods accounting for conflicting objectives in breeding programs for livestock breeds with historical migration.

Science.gov (United States)

Wang, Yu; Bennewitz, Jörn; Wellmann, Robin

2017-05-12

breeds with historical introgressions, current breeding programs should focus on increasing genetic gain and controlling inbreeding, as well as maintaining the genetic originality of the breeds and the diversity of native alleles via the inclusion of MC and kinship at native alleles in the OCS process.

Effects of Low Light on Agronomic and Physiological Characteristics of Rice Including Grain Yield and Quality

Directory of Open Access Journals (Sweden)

Qi-hua LIU

2014-09-01

Full Text Available Light intensity is one of the most important environmental factors that determine the basic characteristics of rice development. However, continuously cloudy weather or rainfall, especially during the grain-filling stage, induces a significant loss in yield and results in poor grain quality. Stress caused by low light often creates severe meteorological disasters in some rice-growing regions worldwide. This review was based on our previous research and related research regarding the effects of low light on rice growth, yield and quality as well as the formation of grain, and mainly reviewed the physiological metabolism of rice plants, including characteristics of photosynthesis, activities of antioxidant enzymes in rice leaves and key enzymes involved in starch synthesis in grains, as well as the translocations of carbohydrate and nitrogen. These characteristics include various grain yield and rice quality components (milling and appearance as well as cooking, eating and nutritional qualities under different rates of shading imposed at the vegetative or reproductive stages of rice plants. Furthermore, we discussed why grain yield and quality are reduced under the low light environment. Next, we summarized the need for future research that emphasizes methods can effectively improve rice grain yield and quality under low light stress. These research findings can provide a beneficial reference for rice cultivation management and breeding program in low light environments.

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

Genetic analysis and identification of SSR markers associated with rice blast disease in a BC2F1 backcross population.

Science.gov (United States)

Hasan, N; Rafii, M Y; Abdul Rahim, H; Nusaibah, S A; Mazlan, N; Abdullah, S

2017-01-23

Rice (Oryza sativa L.) blast disease is one of the most destructive rice diseases in the world. The fungal pathogen, Magnaporthe oryzae, is the causal agent of rice blast disease. Development of resistant cultivars is the most preferred method to achieve sustainable rice production. However, the effectiveness of resistant cultivars is hindered by the genetic plasticity of the pathogen genome. Therefore, information on genetic resistance and virulence stability are vital to increase our understanding of the molecular basis of blast disease resistance. The present study set out to elucidate the resistance pattern and identify potential simple sequence repeat markers linked with rice blast disease. A backcross population (BC 2 F 1 ), derived from crossing MR264 and Pongsu Seribu 2 (PS2), was developed using marker-assisted backcross breeding. Twelve microsatellite markers carrying the blast resistance gene clearly demonstrated a polymorphic pattern between both parental lines. Among these, two markers, RM206 and RM5961, located on chromosome 11 exhibited the expected 1:1 testcross ratio in the BC 2 F 1 population. The 195 BC 2 F 1 plants inoculated against M. oryzae pathotype P7.2 showed a significantly different distribution in the backcrossed generation and followed Mendelian segregation based on a single-gene model. This indicates that blast resistance in PS2 is governed by a single dominant gene, which is linked to RM206 and RM5961 on chromosome 11. The findings presented in this study could be useful for future blast resistance studies in rice breeding programs.

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)

Mutation breeding in crop improvement - achievements and prospects

International Nuclear Information System (INIS)

Kharkwal, M.C.

2004-01-01

Crop improvement programmes through induced mutations were initiated about seven decades ago. Majority of the mutant varieties have been released during the last two decades. In terms of the development and release of mutant varieties, China (605), India (309), Russia (204), the Netherlands (176), USA (125) and Japan (120) are the leading countries. Radiation, especially gamma radiation was the most frequently used mutagen for inducing mutations in crop plants. Out of 1072 mutant varieties of cereals, rice alone accounts for 434 varieties followed by barley (269). Mutation breeding has made significant contribution in increasing the production of rice, ground nut, castor, chickpea, mungbean and urd bean in the Indian subcontinent. The future mutation breeding programmes should be aimed at improving the root characters, nodulation in legumes, alteration of fatty acid composition in oil seeds, host pathogen interactions, photo- insensitivity and apomixix in crop plants

Genetic analysis of rice semidwarf mutant Tad-M-1

International Nuclear Information System (INIS)

Wang Naiyuan; Yang Rencui

1995-01-01

This paper dealed with the inheritance of the rice semidwarf of Tad-M-,a mutant line bred from traditional indica rice Variety Tadukan by radiation. The results indicated that semidwarf of Tad-M-1 was controlled by one pair of recessive gene, which was nonallelic to sd-1 gene of variety Aijiaonante and sd-g gene of variety Xinguiai and allelic to the semidwarf gene of Yunnan japonica variety Xueheaizao and Sichuan indica variety Yizila.The possible uses of Tad-M-1 in rice breeding was also discussed

Effects of water management, connectivity, and surrounding land use on habitat use by frogs in rice paddies in Japan.

Science.gov (United States)

Naito, Risa; Yamasaki, Michimasa; Lmanishi, Ayumi; Natuhara, Yosihiro; Morimoto, Yukihiro

2012-09-01

In Japan, rice paddies play an important role as a substitute habitat for wetland species, and support rich indigenous ecosystems. However, since the 1950s, agricultural modernization has altered the rice paddy environment, and many previously common species are now endangered. It is urgently necessary to evaluate rice paddies as habitats for conservation. Among the species living in rice paddies, frogs are representative and are good indicator species, so we focused on frog species and analyzed the influence of environmental factors on their habitat use. We found four frog species and one subspecies (Hyla japonica, Pelophylax nigromaculatus, Glandirana rugosa, Lithobates catesbeianus, and Pelophylax porosa brevipoda) at our study sites in Shiga prefecture. For all but L. catesbeianus, we analyzed the influence of environmental factors related to rice paddy structure, water management and availability, agrochemical use, connectivity, and land use on breeding and non-breeding habitat use. We constructed generalized additive mixed models with survey date as the smooth term and applied Akaike's information criterion to choose the bestranked model. Because life histories and biological characteristics vary among species, the factors affecting habitat use by frogs are also expected to differ by species. We found that both breeding and non-breeding habitat uses of each studied species were influenced by different combinations of environmental factors and that in most cases, habitat use showed seasonality. For frog conservation in rice paddies, we need to choose favorable rice paddy in relation to surrounding land use and apply suitable management for target species.

Soil-based screening for iron toxicity tolerance in rice using pots

Directory of Open Access Journals (Sweden)

Mouritala Sikirou

2016-10-01

Full Text Available The objective of this study was to assess the reliability of pot-based screening method for iron (Fe toxicity tolerance in rice using soils from hot spots. Five lowland rice varieties with known reaction to Fe toxicity were grown in pots in a screen house for three seasons. Fe-toxic soils from two hot spot fields – Edozighi, Nigeria and Niaouli, Benin were used and soil from Africa Rice Center (AfricaRice experimental farm, Cotonou, Benin was included as control. Leaf bronzing score (LBS was determined at different stages, and grain yield was determined at maturity. Heritability was estimated using data across the three seasons. High heritability was recorded for LBS and grain yield. Grain yield reduction in stress treatment relative to control varied from 15 to 56% depending on the variety and soil. Bao Thai, Suakoko 8, and WITA 4 had better performance under Fe toxicity in terms of LBS, yield and relative yield reduction, whereas Bouake 189 and IR64 had poorer performance. Grain yield and LBS were significantly correlated but negatively at 60 days after sowing (DAS. Overall, the results found in this experiment were consistent with previous field studies. Therefore, pot screening using soils from hot spots can be used by rice breeding programs to reliably assess Fe toxicity tolerance ex situ.

Genome-wide analysis of Dongxiang wild rice (Oryza rufipogon Griff.) to investigate lost/acquired genes during rice domestication.

Science.gov (United States)

Zhang, Fantao; Xu, Tao; Mao, Linyong; Yan, Shuangyong; Chen, Xiwen; Wu, Zhenfeng; Chen, Rui; Luo, Xiangdong; Xie, Jiankun; Gao, Shan

2016-04-26

It is widely accepted that cultivated rice (Oryza sativa L.) was domesticated from common wild rice (Oryza rufipogon Griff.). Compared to other studies which concentrate on rice origin, this study is to genetically elucidate the substantially phenotypic and physiological changes from wild rice to cultivated rice at the whole genome level. Instead of comparing two assembled genomes, this study directly compared the Dongxiang wild rice (DXWR) Illumina sequencing reads with the Nipponbare (O. sativa) complete genome without assembly of the DXWR genome. Based on the results from the comparative genomics analysis, structural variations (SVs) between DXWR and Nipponbare were determined to locate deleted genes which could have been acquired by Nipponbare during rice domestication. To overcome the limit of the SV detection, the DXWR transcriptome was also sequenced and compared with the Nipponbare transcriptome to discover the genes which could have been lost in DXWR during domestication. Both 1591 Nipponbare-acquired genes and 206 DXWR-lost transcripts were further analyzed using annotations from multiple sources. The NGS data are available in the NCBI SRA database with ID SRP070627. These results help better understanding the domestication from wild rice to cultivated rice at the whole genome level and provide a genomic data resource for rice genetic research or breeding. One finding confirmed transposable elements contribute greatly to the genome evolution from wild rice to cultivated rice. Another finding suggested the photophosphorylation and oxidative phosphorylation system in cultivated rice could have adapted to environmental changes simultaneously during domestication.

First report of multiple races of the rice blast fungus Magnaporthe oryzae in Puerto Rico

Science.gov (United States)

The rice nursery located in the Lajas Valley, in the southwestern corner of Puerto Rico has been used by US rice breeders for the past 43 years to produce one to two extra generations per year. In April, 2015, blast disease lesions were observed on rice breeding lines belonging to the USDA ARS DB NR...

Development of breeding objectives for beef cattle breeding ...

African Journals Online (AJOL)

Mnr J F Kluyts

However, to solve the simultaneous equations the ... The aggregate breeding value represents a fundamental concept, the breeding objective, which is ..... Two properties characterise a linear programming problem. The first is additivity, ...

Effective gamma radiation dose for rice genetic improvement by means of mutation radioinduction in Cuba

International Nuclear Information System (INIS)

Perez Talavera, S.; Labrada Remon, A.; Gonzalez, L.M.

1993-01-01

Determination of the useful radiation dosages for its employment in rice breeding in Cuban conditions was made; for this the radio sensibility of three commercial rice varieties was investigated using plant height in laboratory condition as criterion

Association Analysis in Rice: From Application to Utilization

Directory of Open Access Journals (Sweden)

Peng Zhang

2016-08-01

Full Text Available Association analysis based on linkage disequilibrium (LD is an efficient way to dissect complex traits and to identify gene functions in rice. Although association analysis is an effective way to construct fine maps for quantitative traits, there are a few issues which need to be addressed. In this review, we will first summarize type, structure and LD level of populations used for association analysis of rice, and then discuss the genotyping methods and statistical approaches used for association analysis in rice. Moreover, we will review current shortcomings and benefits of association analysis as well as specific types of future research to overcome these shortcomings. Furthermore, we will analyze the reasons for the underutilization of the results within association analysis in rice breeding.

Study on creation and utilization of induced mutation rice materials

International Nuclear Information System (INIS)

Pang Aijun; Peng Weizheng; Pang Boliang; Peng Xuanming; Yang Zhen; Zhang Xianxin; Zhang Yuanhai

2011-01-01

60 Co γ-ray, spaceflight, laser were respectively or combinedly used to treat rice lines or hybrid materials. Many special type of seed breed lines, including high yielding ones, top quality ones, stunt stem ones, disease/pest resistent ones, colourful rices, big size of grain ones etc. were selected from the mutation materials, some were directly used as new varieties and some were indirectly used to breed hybrid varieties. All the new varieties such as 'xiangzaonuo No.1', 'xiangzaoxian No.20', 'xiangzaoxian No.21', 'xiangfu 994', 'peiliangyou 721', 'zhuliangyou 124' were popularly planted and great social and economical benefit was obtained. (authors)

Optimization of dairy cattle breeding programs for different environment with genotype by environment interaction

NARCIS (Netherlands)

Mulder, H.A.; Veerkamp, R.F.; Ducro, B.J.; Arendonk, van J.A.M.; Bijma, P.

2006-01-01

Dairy cattle breeding organizations tend to sell semen to breeders operating in different environments and genotype × environment interaction may play a role. The objective of this study was to investigate optimization of dairy cattle breeding programs for 2 environments with genotype × environment

Rice improvement through radiation-induced mutation for cultivation in South Vietnam

International Nuclear Information System (INIS)

Do Khac Thinh; Hung Phi Oanh; Nguyen Thi Cuc; Nguyen Ngoc Quynh

2001-01-01

For past years, rice varieties cultivated in South Vietnam originated from domestic hybridisation or from IRRI. Rice mutation breeding has been initiated for recent years. To meet the requirement of rice production diversification in different agro-ecological areas and rice genetic resources, from 1993 Institute of Agricultural Science of South Vietnam has carried out rice improvement by induced mutation of radiation. The mutagen was gamma rays of 60 Co. The goal is to create inherited variations, which cannot be obtained from other breeding methods, specially important characters of rice varieties (high tolerance to acid sulfate soil, lodging resistance combined with early maturity), which were difficult to gain by hybridisation. With 60 Co gamma rays, doses of 10-20 krad, dose rate of 280 krad/h, dry and germinated seeds of introduced and local rice varieties (IR 64, IR 9729, IR 50404, IR 59606, Jasmine 85, Nang Huong, Tam Xoan) were irradiated. The irradiated seeds were immediately sown within 24 and 94 hrs for wet seeds and dry seeds after treatment, respectively. Population of 10,000-15,000 plants were established and evaluated by IRRI evaluation standard from M2-M7 generations. 365 lines, varieties were selected with better behaviours than original varieties as lodging resistance, earliness, potential yield, leaf characters, tolerant ability to adverse conditions etc. Some good varieties (VND95-19, VND95-20) have been approved as leading national varieties and released for large-scale production in South Vietnam. (author)

Rice improvement through radiation-induced mutation for cultivation in South Vietnam

Energy Technology Data Exchange (ETDEWEB)

Do Khac Thinh; Hung Phi Oanh; Nguyen Thi Cuc; Nguyen Ngoc Quynh [Institute of Agricultural Science of South Vietnam, Ho Chi Minh (Viet Nam)

2001-03-01

For past years, rice varieties cultivated in South Vietnam originated from domestic hybridisation or from IRRI. Rice mutation breeding has been initiated for recent years. To meet the requirement of rice production diversification in different agro-ecological areas and rice genetic resources, from 1993 Institute of Agricultural Science of South Vietnam has carried out rice improvement by induced mutation of radiation. The mutagen was gamma rays of {sup 60}Co. The goal is to create inherited variations, which cannot be obtained from other breeding methods, specially important characters of rice varieties (high tolerance to acid sulfate soil, lodging resistance combined with early maturity), which were difficult to gain by hybridisation. With {sup 60}Co gamma rays, doses of 10-20 krad, dose rate of 280 krad/h, dry and germinated seeds of introduced and local rice varieties (IR 64, IR 9729, IR 50404, IR 59606, Jasmine 85, Nang Huong, Tam Xoan) were irradiated. The irradiated seeds were immediately sown within 24 and 94 hrs for wet seeds and dry seeds after treatment, respectively. Population of 10,000-15,000 plants were established and evaluated by IRRI evaluation standard from M2-M7 generations. 365 lines, varieties were selected with better behaviours than original varieties as lodging resistance, earliness, potential yield, leaf characters, tolerant ability to adverse conditions etc. Some good varieties (VND95-19, VND95-20) have been approved as leading national varieties and released for large-scale production in South Vietnam. (author)

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

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

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.

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)

Radiation mutation breeding

Energy Technology Data Exchange (ETDEWEB)

Song, Hi Sup; Kim, Jae Sung; Kim, Jin Kyu; Shin, In Chul; Lim, Young Taek

1998-04-01

In order to develop an advanced technical knowledge for the selection of better mutants, some of the crops were irradiated and the mutation rate, the survival rate and the method for selction of a mutant were studied. Furthermore, this study aimed to obtain basic data applicable to the development of genetic resources by evaluation and analysis the specific character for selection of the superior mutant and its plant breeding. 1. selection of the mutant with a superior resistance against environment in the principal crops 1) New varieties of mutant rices such as Wonpyeongbyeo, Wongwangbyeo, Winmibyeo, and heogseon chalbeyeo (sticky forma) were registered in the national variety list and made an application to crop variety protection right. They are under review now. 2) We also keep on studying on the number of a grain of 8 lines of excellent mutant rice for the purpose of improvement of breeding . 3) We selected 3 lines which have a resistance to pod and stem blight in large soybean, 31 lines with small grain size and higher yield, 112 lines of soybean of cooking, 7 lines of low lipoxygenase content, and 12 lines with decreased phytic acid content by 20 % compared to the previous level. 2. Selection of advanced Mugunwha (Rose of Sharon) mutant 1) Bagseul, a new variety of mutant, was developed and 30 plantlets of it are being proliferated. 2) Fifty-three lines of a mutant having a various morphologies were selected.

Radiation mutation breeding

International Nuclear Information System (INIS)

Song, Hi Sup; Kim, Jae Sung; Kim, Jin Kyu; Shin, In Chul; Lim, Young Taek

1998-04-01

In order to develop an advanced technical knowledge for the selection of better mutants, some of the crops were irradiated and the mutation rate, the survival rate and the method for selction of a mutant were studied. Furthermore, this study aimed to obtain basic data applicable to the development of genetic resources by evaluation and analysis the specific character for selection of the superior mutant and its plant breeding. 1. selection of the mutant with a superior resistance against environment in the principal crops 1) New varieties of mutant rices such as Wonpyeongbyeo, Wongwangbyeo, Winmibyeo, and heogseon chalbeyeo (sticky forma) were registered in the national variety list and made an application to crop variety protection right. They are under review now. 2) We also keep on studying on the number of a grain of 8 lines of excellent mutant rice for the purpose of improvement of breeding . 3) We selected 3 lines which have a resistance to pod and stem blight in large soybean, 31 lines with small grain size and higher yield, 112 lines of soybean of cooking, 7 lines of low lipoxygenase content, and 12 lines with decreased phytic acid content by 20 % compared to the previous level. 2. Selection of advanced Mugunwha (Rose of Sharon) mutant 1) Bagseul, a new variety of mutant, was developed and 30 plantlets of it are being proliferated. 2) Fifty-three lines of a mutant having a various morphologies were selected

Quantitative Genetic Analysis for Yield and Yield Components in Boro Rice (Oryza sativa L.

Directory of Open Access Journals (Sweden)

Supriyo CHAKRABORTY

2010-03-01

Full Text Available Twenty-nine genotypes of boro rice (Oryza sativa L. were grown in a randomized block design with three replications in plots of 4m x 1m with a crop geometry of 20 cm x 20 cm between November-April, in Regional Agricultural Research Station, Nagaon, India. Quantitative data were collected on five randomly selected plants of each genotype per replication for yield/plant, and six other yield components, namely plant height, panicles/plant, panicle length, effective grains/panicle, 100 grain weight and harvest index. Mean values of the characters for each genotype were used for analysis of variance and covariance to obtain information on genotypic and phenotypic correlation along with coheritability between two characters. Path analyses were carried out to estimate the direct and indirect effects of boro rice�s yield components. The objective of the study was to identify the characters that mostly influence the yield for increasing boro rice productivity through breeding program. Correlation analysis revealed significant positive genotypic correlation of yield/plant with plant height (0.21, panicles/plant (0.53, panicle length (0.53, effective grains/panicle (0.57 and harvest index (0.86. Path analysis based on genotypic correlation coefficients elucidated high positive direct effect of harvest index (0.8631, panicle length (0.2560 and 100 grain weight (0.1632 on yield/plant with a residual effect of 0.33. Plant height and panicles/plant recorded high positive indirect effect on yield/plant via harvest index whereas effective grains/panicle on yield/plant via harvest index and panicle length. Results of the present study suggested that five component characters, namely harvest index, effective grains/plant, panicle length, panicles/plant and plant height influenced the yield of boro rice. A genotype with higher magnitude of these component characters could be either selected from the existing genotypes or evolved by breeding program for genetic

Global Rice Watch: Spatial-temporal dynamics, driving factors, and impacts of paddy rice agriculture in the world

Science.gov (United States)

Xiao, X.; Dong, J.; Zhang, G.; Xin, F.; Li, X.

2017-12-01

Paddy rice croplands account for more than 12% of the global cropland areas, and provide food to feed more than 50% of the world population. Spatial patterns and temporal dynamics of paddy rice croplands have changed remarkably in the past decades, driven by growing human population and their changing diet structure, land use (e.g., urbanization, industrialization), climate, markets, and technologies. In this presentation, we will provide a comprehensive review of our current knowledge on (1) the spatial patterns and temporal dynamics of paddy rice croplands from agricultural statistics data and remote sensing approaches; (2) major driving factors for the observed changes in paddy rice areas, including social, economic, climate, land use, markets, crop breeding technology, and farming technology; and (3) major impacts on atmospheric methane concentration, land surface temperature, water resources and use, and so on. We will highlight the results from a few case studies in China and monsoon Asia. We will also call for a global synthesis analysis of paddy rice agriculture, and invite researchers to join the effort to write and edit a book that provides comprehensive and updated knowledge on paddy rice agriculture.

ROOT ANATOMICAL PLASTICITY IN RESPONSE TO SALT STRESS UNDER REAL AND FULL-SEASON FIELD CONDITIONS AND DETERMINATION OF NEW ANATOMIC SELECTION CHARACTERS FOR BREEDING SALT-RESISTANT RICE (Oryza sativa L.

Directory of Open Access Journals (Sweden)

Mehmet AYBEKE

2016-12-01

Full Text Available Specific understanding of root anatomy plasticity under salt stress is lacking and requires creation of efficient screening techniques for stress condition s. To fill this gap, this study aimed to determine the anatomical plasticity in root chracteristics of 31 different rice cultivars (from ‘Best’ to ‘Low’ yielding grown under real field conditions (saline and non-saline from planting to harvesting and to reveal detailed root anatomical parameters that can be used to select and breed salt-tolerant rice. Anatomical and histochemical features of all cultivars and thin structures of the apoplastic barriers were investigated. The amount of silica (Si, 35 different anatomical characteristics, anatomical plasticity characteristics, plasticity rates, plasticity trends and changes and strategies of each group under saline and non-saline conditions were compared. The results showed that protective anatomical characters improved/remained equal to, and worsened/remained equal to those of the controls, in the ‘Best’ and other groups, respectively, from non-saline to saline conditions. Anatomical plasticity is essentially directly related to apoplastic barrier features. High genotypic variation was observed in root anatomy in all cultivars, but foremost traits were as follows: (1 cell size, (2 Si presence, (3 Si accumulation shape, (4 Si distribution towards root stele, (5 xylem arch features, (6 lignification-suberization properties in apoplastic barriers and their degrees, (7 presence/absence of idioblast cells filled with gummic and phenolic substances and (8 moderate anatomical plasticity. Cultivars with the most stabile anatomy under saline and non-saline conditions should be used to select and breed salt-resistant rice.

Genomic diversity and introgression in O. sativa reveal the impact of domestication and breeding on the rice genome.

Directory of Open Access Journals (Sweden)

Keyan Zhao

2010-05-01

Full Text Available The domestication of Asian rice (Oryza sativa was a complex process punctuated by episodes of introgressive hybridization among and between subpopulations. Deep genetic divergence between the two main varietal groups (Indica and Japonica suggests domestication from at least two distinct wild populations. However, genetic uniformity surrounding key domestication genes across divergent subpopulations suggests cultural exchange of genetic material among ancient farmers.In this study, we utilize a novel 1,536 SNP panel genotyped across 395 diverse accessions of O. sativa to study genome-wide patterns of polymorphism, to characterize population structure, and to infer the introgression history of domesticated Asian rice. Our population structure analyses support the existence of five major subpopulations (indica, aus, tropical japonica, temperate japonica and GroupV consistent with previous analyses. Our introgression analysis shows that most accessions exhibit some degree of admixture, with many individuals within a population sharing the same introgressed segment due to artificial selection. Admixture mapping and association analysis of amylose content and grain length illustrate the potential for dissecting the genetic basis of complex traits in domesticated plant populations.Genes in these regions control a myriad of traits including plant stature, blast resistance, and amylose content. These analyses highlight the power of population genomics in agricultural systems to identify functionally important regions of the genome and to decipher the role of human-directed breeding in refashioning the genomes of a domesticated species.

Analysis of QTLs Associated with the Rice Quality Related Gene by Double Haploid Populations

Science.gov (United States)

Lee, Gyu-Ho; Yun, Byung-Wook

2014-01-01

We investigated the growth characteristics and analyzed the physicochemical properties of a doubled haploid population derived from a cross between “Cheongcheong” and “Nagdong” to breed a rice variety that tastes good after cooking and to detect quantitative trait loci (QTLs) associated with the taste of cooked rice. The results showed that these compounds also represent a normal distribution. Correlation analysis of the amylose, protein, and lipid contents indicated that each compound is related to the taste of cooked rice. The QTLs related to amylose content were 4 QTLs, protein content was 2 QTLs, and lipid content was 2 QTLs. Four of the QTLs associated with amylose content were detected on chromosomes 7 and 11. The index of coincidence for the QTLs related to amylose, protein, and lipid content was 70%, respectively. These markers showing high percentage of coincidence can be useful to select desirable lines for rice breeding. PMID:25478566

Analysis of QTLs Associated with the Rice Quality Related Gene by Double Haploid Populations

Directory of Open Access Journals (Sweden)

Gyu-Ho Lee

2014-01-01

Full Text Available We investigated the growth characteristics and analyzed the physicochemical properties of a doubled haploid population derived from a cross between “Cheongcheong” and “Nagdong” to breed a rice variety that tastes good after cooking and to detect quantitative trait loci (QTLs associated with the taste of cooked rice. The results showed that these compounds also represent a normal distribution. Correlation analysis of the amylose, protein, and lipid contents indicated that each compound is related to the taste of cooked rice. The QTLs related to amylose content were 4 QTLs, protein content was 2 QTLs, and lipid content was 2 QTLs. Four of the QTLs associated with amylose content were detected on chromosomes 7 and 11. The index of coincidence for the QTLs related to amylose, protein, and lipid content was 70%, respectively. These markers showing high percentage of coincidence can be useful to select desirable lines for rice breeding.

Determinants of molecular marker based classification of rice (Oryza ...

African Journals Online (AJOL)

mr devi singh

2015-01-07

Jan 7, 2015 ... 1Molecular Biology Laboratory, Department of Genetics and Plant Breeding, SVP University of Agriculture and ... Basmati and non-Basmati rice adapted to different agro- ecological ..... acid soils in southern New South Wales?

The use of mutant stock for semi-dwarf plant type and early maturity as cross-breeding materials in rice (coordinated programme on semi-dwarf mutants for rice improvement in Asia and the Pacific Region - RCA)

International Nuclear Information System (INIS)

Pookamana, P.

1985-11-01

Development of semi-dwarf type varieties has led to a substantial yield increase in Thailand, where rice is cultivated on areas of about 8 million hectars. Of 19 recommended Thai rice varieties, 10 possess the DGWG gene which determines semi-dwarf character. This situation can create some problems in terms of genetic vulnerability towards pests, diseases and other adverse stresses. The authors found that susceptibility to disease and insect pests as well as poor grain quality are major drawbacks associated with the DGWG gene. With this background, the major project goal was to obtain, by mutation techniques, a new genetic source of semi-dwarfness. For this purpose 3 tall local Thai varieties (Leaung Awn 29, Niaw Sanpah Tawng and Khao Dawk Mali) with very good grain quality, were chosen as parent material. Using radiation techniques 2 glutinous and 7 non-glutinous semi-dwarf mutants were obtained. Results of agronomic trials indicated that the mutants from local varieties were more promising and higher yielding in comparison to introduced varieties from IRRI, Taiwan, China, France and the USA. The preliminary genetics analysis of these mutants indicated an allelic relationship to the DGWG gene. This result is very important for the rice breeding programme because it made available the semi-dwarf gene in a new genetic background - with desirable characteristics for cultivation in Thailand. These positive results stimulated efforts to obtain new semi-dwarf mutants from other local, lowland rice varieties such as Leaung Tawang and Leb Mue Nahng 111. 49 and 35 semi-dwarf mutants were already selected after irradiation and are now under agronomic evaluation

Iron-biofortified rice improves the iron stores of nonanemic Filipino women.

Science.gov (United States)

Haas, Jere D; Beard, John L; Murray-Kolb, Laura E; del Mundo, Angelita M; Felix, Angelina; Gregorio, Glenn B

2005-12-01

Iron deficiency is endemic in much of the world, and food system-based approaches to eradication may be viable with new plant breeding approaches to increase the micronutrient content in staple crops. It is thought that conventional plant breeding approaches provide varieties of rice that have 400-500% higher iron contents than varieties commonly consumed in much of Asia. The efficacy of consuming high-iron rice was tested during a 9-mo feeding trial with a double-blind dietary intervention in 192 religious sisters living in 10 convents around metro Manila, the Philippines. Subjects were randomly assigned to consume either high-iron rice (3.21 mg/kg Fe) or a local variety of control rice (0.57 mg/kg Fe), and daily food consumption was monitored. The high-iron rice contributed 1.79 mg Fe/d to the diet in contrast to 0.37 mg Fe/d from the control rice. The 17% difference in total dietary iron consumption compared with controls (10.16 +/- 1.06 vs. 8.44 +/- 1.82 mg/d) resulted in a modest increase in serum ferritin (P = 0.10) and total body iron (P = 0.06) and no increase in hemoglobin (P = 0.59). However, the response was greater in nonanemic subjects for ferritin (P = 0.02) and body iron (P = 0.05), representing a 20% increase after controlling for baseline values and daily rice consumption. The greatest improvements in iron status were seen in those nonanemic women who had the lowest baseline iron status and in those who consumed the most iron from rice. Consumption of biofortified rice, without any other changes in diet, is efficacious in improving iron stores of women with iron-poor diets in the developing world.

Micronutrient-fortified rice can increase hookworm infection risk

DEFF Research Database (Denmark)

de Gier, Brechje; Campos Ponce, Maiza; Perignon, Marlene

2016-01-01

or inflammation after iron supplementation. OBJECTIVE: To study effects of micronutrient-fortified rice on hookworm infection in Cambodian schoolchildren. METHODS: A double-blinded, cluster-randomized trial was conducted in 16 Cambodian primary schools partaking in the World Food Program school meal program....... Three types of multi-micronutrient fortified rice were tested against placebo rice within the school meal program: UltraRice_original, UltraRice_improved and NutriRice. Four schools were randomly assigned to each study group (placebo n = 492, UltraRice_original n = 479, UltraRice_improved n = 500, NutriRice.......6%, but differed considerably among schools (range 0%- 48.1%).Micronutrient-fortified rice significantly increased risk of new hookworm infection. This effect was modified by baseline hookworm prevalence at the school; hookworm infection risk was increased by all three types of fortified rice in schools where...

Structuring an Efficient Organic Wheat Breeding Program

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P. Stephen Baenziger

2011-08-01

Full Text Available Our long-term goal is to develop wheat cultivars that will improve the profitability and competitiveness of organic producers in Nebraska and the Northern Great Plains. Our approach is to select in early generations for highly heritable traits that are needed for both organic and conventional production (another breeding goal, followed by a targeted organic breeding effort with testing at two organic locations (each in a different ecological region beginning with the F6 generation. Yield analyses from replicated trials at two organic breeding sites and 7 conventional breeding sites from F6 through F12 nurseries revealed, using analyses of variance, biplots, and comparisons of selected lines that it is inappropriate to use data from conventional testing for making germplasm selections for organic production. Selecting and testing lines under organic production practices in different ecological regions was also needed and cultivar selections for organic production were different than those for conventional production. Modifications to this breeding protocol may include growing early generation bulks in an organic cropping system. In the future, our selection efforts should also focus on using state-of-the-art, non-transgenic breeding technologies (genomic selection, marker-assisted breeding, and high throughput phenotyping to synergistically improve organic and conventional wheat breeding.

Simulated selection responses for breeding programs including resistance and resilience to parasites in Creole goats

NARCIS (Netherlands)

Gunia, M.; Phocas, F.; Gourdine, J.L.; Bijma, P.; Mandonnet, N.

2013-01-01

The Creole goat is a local breed used for meat production in Guadeloupe (French West Indies). As in other tropical countries, improvement of parasite resistance is needed. In this study, we compared predicted selection responses for alternative breeding programs with or without parasites resistance

APPLICATION OF MOLECULAR METHODS IN SOYBEAN BREEDING PROGRAM AT THE AGRICULTURAL INSTITUTE OSIJEK (CROATIA

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Aleksandra Sudarić

2008-09-01

Full Text Available The soybean breeding work at the Agricultural Institute Osijek has focused on the permanently development of high-yielding cultivars with genetic yield potential of 5-6 t/ha, satisfactory grain quality (protein and oil content, high tolerance to the principal diseases (Peronospora manshurica, Sclerotinia sclerotiorum, Diaporthe/Phomopsis complex, high resistance to lodging, stress conditions over vegetation and pod shattering as well as satisfactory stability in level and quality of grain and wide adaptability. Results of this continued and intensive breeding work are 36 registered cultivars which significantly contributed and contribute to the development, improving and increasing of soybean production in Republic of Croatia. Further genetic improvement of soybean cultivars is based on the modern breeding strategies including combination of conventional breeding methods and recent chemical, biochemical, phytopathology and molecular analyses. Regarding to molecular analyses, in recent years, in the frame of the soybean breeding program has initiated by application of molecular markers technology as criterion for estimation genetic diversity for both soybean germplasm and pathogens from Diaporthe/Phomopsis complex on soybean, as well. The initial fingerprinting of several OS soybean genotypes has performed in collaboration with the University of Guelph (Canada in their biomolecular laboratory using simple sequence repeats (SSR. The obtained results enabled new access in choosing parental pairs. Combining molecular markers technique with pedigree information, phenotypic markers and statistical procedure has provided a useful tool for more accurate and complete evaluation of genetic diversity and its more effective utilization into current soybean breeding program. The detection of pathogens from Diaporthe/Phomopsis complex on soybean on molecular level has performed in collaboration with the Istituto Sperimentale per la Patologia Vegetale (Rome

Mitigation of inbreeding while preserving genetic gain in genomic breeding programs for outbred plants.

Science.gov (United States)

Lin, Zibei; Shi, Fan; Hayes, Ben J; Daetwyler, Hans D

2017-05-01

Heuristic genomic inbreeding controls reduce inbreeding in genomic breeding schemes without reducing genetic gain. Genomic selection is increasingly being implemented in plant breeding programs to accelerate genetic gain of economically important traits. However, it may cause significant loss of genetic diversity when compared with traditional schemes using phenotypic selection. We propose heuristic strategies to control the rate of inbreeding in outbred plants, which can be categorised into three types: controls during mate allocation, during selection, and simultaneous selection and mate allocation. The proposed mate allocation measure GminF allocates two or more parents for mating in mating groups that minimise coancestry using a genomic relationship matrix. Two types of relationship-adjusted genomic breeding values for parent selection candidates ([Formula: see text]) and potential offspring ([Formula: see text]) are devised to control inbreeding during selection and even enabling simultaneous selection and mate allocation. These strategies were tested in a case study using a simulated perennial ryegrass breeding scheme. As compared to the genomic selection scheme without controls, all proposed strategies could significantly decrease inbreeding while achieving comparable genetic gain. In particular, the scenario using [Formula: see text] in simultaneous selection and mate allocation reduced inbreeding to one-third of the original genomic selection scheme. The proposed strategies are readily applicable in any outbred plant breeding program.

Water management for controlling the breeding of Anopheles mosquitoes in rice irrigation schemes in Kenya

DEFF Research Database (Denmark)

Mutero, C M; Blank, H; Konradsen, F

2000-01-01

abundance fluctuated throughout the 12-week sampling period. The highest larval densities were recorded in the 3 weeks after transplanting the rice seedlings. Afterwards, larval numbers dropped dramatically as the height of rice plants increased. Rice yields at harvest did not show statistically significant...

Integration of genomic information into sport horse breeding programs for optimization of accuracy of selection.

Science.gov (United States)

Haberland, A M; König von Borstel, U; Simianer, H; König, S

2012-09-01

Reliable selection criteria are required for young riding horses to increase genetic gain by increasing accuracy of selection and decreasing generation intervals. In this study, selection strategies incorporating genomic breeding values (GEBVs) were evaluated. Relevant stages of selection in sport horse breeding programs were analyzed by applying selection index theory. Results in terms of accuracies of indices (r(TI) ) and relative selection response indicated that information on single nucleotide polymorphism (SNP) genotypes considerably increases the accuracy of breeding values estimated for young horses without own or progeny performance. In a first scenario, the correlation between the breeding value estimated from the SNP genotype and the true breeding value (= accuracy of GEBV) was fixed to a relatively low value of r(mg) = 0.5. For a low heritability trait (h(2) = 0.15), and an index for a young horse based only on information from both parents, additional genomic information doubles r(TI) from 0.27 to 0.54. Including the conventional information source 'own performance' into the before mentioned index, additional SNP information increases r(TI) by 40%. Thus, particularly with regard to traits of low heritability, genomic information can provide a tool for well-founded selection decisions early in life. In a further approach, different sources of breeding values (e.g. GEBV and estimated breeding values (EBVs) from different countries) were combined into an overall index when altering accuracies of EBVs and correlations between traits. In summary, we showed that genomic selection strategies have the potential to contribute to a substantial reduction in generation intervals in horse breeding programs.

Induction of rice mutations by high hydrostatic pressure.

Science.gov (United States)

Zhang, Wei; Liu, Xuncheng; Zheng, Feng; Zeng, Songjun; Wu, Kunlin; da Silva, Jaime A Teixeira; Duan, Jun

2013-09-01

High hydrostatic pressure (HHP) is an extreme thermo-physical factor that affects the synthesis of DNA, RNA and proteins and induces mutagenesis in microorganisms. Our previous studies showed that exposure to 25-100 MPa HHP for 12 h retarded the germination and affected the viability of rice (Oryza sativa L.) seeds, increased the tolerance of rice plants to cold stress and altered gene expression patterns in germinating rice seeds. However, the mutagenic effect of HHP on rice remains unknown. In this study, exposure to 25, 50, 75 or 100 MPa for 12 h HHP could efficiently induce variation in rice plants. Furthermore, presoaking time and HHP strength during HHP treatment affected the efficiency of mutation. In addition, the Comet assay revealed that exposure to 25-100 MPa HHP for 12 h induced DNA strand breakage in germinating seeds and may have been the source of mutations. Our results suggest that HHP is a promising physical mutagen in rice breeding. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

A simple language to script and simulate breeding schemes: the breeding scheme language

Science.gov (United States)

It is difficult for plant breeders to determine an optimal breeding strategy given that the problem involves many factors, such as target trait genetic architecture and breeding resource availability. There are many possible breeding schemes for each breeding program. Although simulation study may b...

Use of radiation for plant breeding in Japan: results and future

International Nuclear Information System (INIS)

Yamaguchi, I.

1998-01-01

In 1966, as the first breeds by radiation mutation in Japan, 'Reimei', a rice variety with increased lodging resistance by short culm mutation and Raiden', an early variety by mutation of soybean obtained by extreme late variety with nematoda resistance were bred and registered in the Ministry of Agriculture and Forestry. Since these characteristics of 'short culm' and early maturing' have a comparatively high mutation rate and ease of selection, among seed propagation crops many kinds of those varieties improved to have either of these characteristics or both of them at the same time by mutation breeding are bred. In Japan, varieties bred by use of mutation breeding count 107 (as of April 1998). Among crops, that with the most varieties is chrysanthemum, which has 20 varieties and the next is rice with 15 varieties. The other 38 varieties of crops such as grains, beans, industrial crops, vegetables, flowering plants, flowering trees and fruit trees, mutation breeding varieties are widely bred. Among mutagens used, gamma ray holds 80%. The recent development in the research of DNA recombination is amazing and plant bodies which have introduced useful genes which other plants have are being obtained. Radiation mutation breeding, however, has the advantages of breeding new varieties by improving only one or two characteristics of excellent races. Radiation mutation breeding and DNA recombination technologies, therefore, may need to be utilized separately according to respective purposes. In the future, for radiation mutation breeding, mutants with quality characteristics which others do not have, corresponding to the diverse demand on agricultural products must come to be required. On the other hand, by the crops like banana for which ordinary breeding is almost impossible, the expectation for radiation mutation breeding will be more and more heightened. In addition, the accumulation of studies on controlling the direction of mutation which has been regarded

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.

Role of varieties in sustainable rice production in Malaysia

International Nuclear Information System (INIS)

Othman Omar; Saad Abdullah

2002-01-01

Rice is the staple food of Malaysians. Rice production in Malaysia is concentrated in granary areas, which are provided with irrigation facilities. There is no plan to increase the size or the number of these granary areas, thus productivity per unit area must be increased to sustain the current level of self-sufficiency. Variety determines the potential productivity; environment and crop management determine how much of this potential is realized. Crop management is very important, as any drop in the level of management will effect productivity. However there are characteristics / factors that can be incorporated into varieties which can buffer the effect of environment and crop management. Pests and diseases can result in severe yield loss and lead to non-sustainable production. Varietal resistance to some of these diseases can be incorporated into rice varieties. Active breeding to incorporate rice resistance to blast, PMV (tungro), bacterial blight and brown planthopper is being currently carried out Factors that determine or justify the active breeding status are: importance of Oe pests diseases, resistance sources and the availability of efficient screening procedure. Sheath blight is also an important disease in direct seeded crops as it can cause severe yield loss, but good resistant sources are not available for incorporation and the screening procedure is also not very efficient. Biotechnologists are working hard to introduce resistance from other crops and also develop other resistance mechanisms for sheath blight. Water, shortage or excess, is a major cause of non-sustainable production. The breeding of short-term varieties can overcome water problems or shortages. Negative interaction between varietal characteristics and environment do occur. Finally farmers have to decide which factors of the environment cannot be easily controlled, and choose the correct varieties in order to achieve sustainable production. (Author)

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

Economic and Environmental Impact of Rice Blast Pathogen (Magnaporthe oryzae) Alleviation in the United States.

Science.gov (United States)

Nalley, Lawton; Tsiboe, Francis; Durand-Morat, Alvaro; Shew, Aaron; Thoma, Greg

2016-01-01

Rice blast (Magnaporthe oryzae) is a key concern in combating global food insecurity given the disease is responsible for approximately 30% of rice production losses globally-the equivalent of feeding 60 million people. These losses increase the global rice price and reduce consumer welfare and food security. Rice is the staple crop for more than half the world's population so any reduction in rice blast would have substantial beneficial effects on consumer livelihoods. In 2012, researchers in the US began analyzing the feasibility of creating blast-resistant rice through cisgenic breeding. Correspondingly, our study evaluates the changes in producer, consumer, and environmental welfare, if all the rice produced in the Mid-South of the US were blast resistant through a process like cisgenics, using both international trade and environmental assessment modeling. Our results show that US rice producers would gain 69.34 million dollars annually and increase the rice supply to feed an additional one million consumers globally by eliminating blast from production in the Mid-South. These results suggest that blast alleviation could be even more significant in increasing global food security given that the US is a small rice producer by global standards and likely experiences lower losses from blast than other rice-producing countries because of its ongoing investment in production technology and management. Furthermore, results from our detailed life cycle assessment (LCA) show that producing blast-resistant rice has lower environmental (fossil fuel depletion, ecotoxicity, carcinogenics, eutrophication, acidification, global warming potential, and ozone depletion) impacts per unit of rice than non-blast resistant rice production. Our findings suggest that any reduction in blast via breeding will have significantly positive impacts on reducing global food insecurity through increased supply, as well as decreased price and environmental impacts in production.

Economic and Environmental Impact of Rice Blast Pathogen (Magnaporthe oryzae Alleviation in the United States.

Directory of Open Access Journals (Sweden)

Lawton Nalley

Full Text Available Rice blast (Magnaporthe oryzae is a key concern in combating global food insecurity given the disease is responsible for approximately 30% of rice production losses globally-the equivalent of feeding 60 million people. These losses increase the global rice price and reduce consumer welfare and food security. Rice is the staple crop for more than half the world's population so any reduction in rice blast would have substantial beneficial effects on consumer livelihoods. In 2012, researchers in the US began analyzing the feasibility of creating blast-resistant rice through cisgenic breeding. Correspondingly, our study evaluates the changes in producer, consumer, and environmental welfare, if all the rice produced in the Mid-South of the US were blast resistant through a process like cisgenics, using both international trade and environmental assessment modeling. Our results show that US rice producers would gain 69.34 million dollars annually and increase the rice supply to feed an additional one million consumers globally by eliminating blast from production in the Mid-South. These results suggest that blast alleviation could be even more significant in increasing global food security given that the US is a small rice producer by global standards and likely experiences lower losses from blast than other rice-producing countries because of its ongoing investment in production technology and management. Furthermore, results from our detailed life cycle assessment (LCA show that producing blast-resistant rice has lower environmental (fossil fuel depletion, ecotoxicity, carcinogenics, eutrophication, acidification, global warming potential, and ozone depletion impacts per unit of rice than non-blast resistant rice production. Our findings suggest that any reduction in blast via breeding will have significantly positive impacts on reducing global food insecurity through increased supply, as well as decreased price and environmental impacts in

Considering genetic characteristics in German Holstein breeding programs.

Science.gov (United States)

Segelke, D; Täubert, H; Reinhardt, F; Thaller, G

2016-01-01

Recently, several research groups have demonstrated that several haplotypes may cause embryonic loss in the homozygous state. Up to now, carriers of genetic disorders were often excluded from mating, resulting in a decrease of genetic gain and a reduced number of sires available for the breeding program. Ongoing research is very likely to identify additional genetic defects causing embryonic loss and calf mortality by genotyping a large proportion of the female cattle population and sequencing key ancestors. Hence, a clear demand is present to develop a method combining selection against recessive defects (e.g., Holstein haplotypes HH1-HH5) with selection for economically beneficial traits (e.g., polled) for mating decisions. Our proposed method is a genetic index that accounts for the allele frequencies in the population and the economic value of the genetic characteristic without excluding carriers from breeding schemes. Fertility phenotypes from routine genetic evaluations were used to determine the economic value per embryo lost. Previous research has shown that embryo loss caused by HH1 and HH2 occurs later than the loss for HH3, HH4, and HH5. Therefore, an economic value of € 97 was used against HH1 and HH2 and € 70 against HH3, HH4, and HH5. For polled, € 7 per polled calf was considered. Minor allele frequencies of the defects ranged between 0.8 and 3.3%. The polled allele has a frequency of 4.1% in the German Holstein population. A genomic breeding program was simulated to study the effect of changing the selection criteria from assortative mating based on breeding values to selecting the females using the genetic index. Selection for a genetic index on the female path is a useful method to control the allele frequencies by reducing undesirable alleles and simultaneously increasing economical beneficial characteristics maintaining most of the genetic gain in production and functional traits. Additionally, we applied the genetic index to real data and

Do traditional sheep breeders perform conscious selection? An example from a participatory breeding program of Morada Nova sheep.

Science.gov (United States)

Arandas, Janaina Kelli Gomes; Alves, Ângelo Giuseppe Chaves; Facó, Olivardo; Belchior, Ernandes Barboza; Shiotsuki, Luciana; de Arruda Leite, Paulo Márcio Barbosa; Ribeiro, Maria Norma

2017-10-01

The implementation of sustainable breeding programs requires genetic breeding strategies that are appropriate for the reality production systems. It is also essential that the choice of animal selection criteria be based on breeders' knowledge and objectives. This work is an ethno-zootechnical study of the Morada Nova sheep breed and its crossbreeds. The goals of this study were to register and analyze indigenous breeders' knowledge and practices regarding animal selection criteria and to generate technical information to support a participatory breeding program of the breed. This study was conducted in the Morada Nova municipality in the state of Ceará, Brazil. Semi-structured interviews were evaluated using two groups of individuals, purebred Morada Nova sheep breeders (RMN, n = 13) and breeders of Morada Nova crossbreeds (MMN, n = 48). Interview questions were used to identify local selection criteria adopted by each group in the choice of animals for breeding. Data from the interviews were submitted to frequency distribution analysis and the Shapiro-Wilk test to verify their distribution. Later, the Kruskal-Wallis test was used to compare the two groups of farmers based on that information, in addition to multivariate statistical analysis and evaluation of Smith salience index. Breeders in the RMN group used selection criteria related to breed standards, such as pelage color. In contrast, breeders of the MMN group used criteria related to productivity, such as body conformation and milk production. Breeders should be engaged in the development of breeding programs, and it is important to consider their preferences and objectives when evaluating breeding animals.

Plant breeding by using radiation mutation

International Nuclear Information System (INIS)

Song, Hi Sup; Kim, Jin Kyu; Shin, In Chul and others; Yang, Seung Gyun; Choi, Soon Ho; Lee, Jang Ha; Lee, Hyo Yeon; Seo, Yong Won; Lim, Yong Pyo

2003-04-01

To improve the crop varieties by using radiation mutation, various mutant lines were selected from the materials irradiated with gamma ray by both in vivo and in vitro mutagenesis. As in vitro selection breeding, various cell lines each with salt, 5-MT and Systeine tolerance were selected from the irradiated calli of rice, and then DNA and molecular markers related with their tolerances were identified. And the rice mutant lines selected from cell lines were evaluated and then some of promising lines were selected by the field trial. Four mutant rice cultivars(Wonmibyeo, Wonpyongbyeo, Heugseonchalbyeo, Wongwangbyeo) were released and their seeds were distributed to farmers. A high quality mutant rice cultivar, Woncheongbyeo, was newly registered. And developed five new cultivars, Wonkangbyeo, Wonpumbyeo, Wonchubyeo, Heugkwangchalbyeo, Nogwonchalbyeo and three mutant cultivars of the rose of Sharon (Mugunghwa) such as Ggoma, Seonnyo, Daegwang were applied to register the national new cultivar list. About promising 30 mutant lines of rice and Mugunghwa were done the field trials and proliferation. Promising soybean mutant lines were selected for improvement of soybean disease resistant, ecological traits and soybean seed quality. Other related two researches not only on development of disease tolerant lines of hot pepper, but also on development of herbicide-resistant cell lines using radiation irradiation, were carried out as a joint projects

Use of γ-ray-induced mutations in the genome era in rice

International Nuclear Information System (INIS)

Kusaba, Makoto

2007-01-01

Ionizing radiation has been used for inducing mutations and improving crops since the discovery by STADLER (1928) that X-rays could induce mutations in barley. At the end of 2004, the whole genome sequence of rice was determined (INTERNATIONAL RICE GENOME SEQUENCING PROJECT, 2005). What can γ-ray-induced mutations contribute now that this has been achieved? One answer could be the elucidation of the functions of the numerous genes revealed by the complete sequence of the rice genome. This includes identification of mutants through reverse genetics and the isolation of genes containing mutations through forward genetics using molecular markers and sequence information. Another answer could be mutation breeding using reverse genetics. But first we must know what kind of DNA lesions are caused by γ-rays. In this article, I describe the production of DNA lesions, and then discuss how γ-ray-induced mutations can contribute to the elucidation of gene function and to mutation breeding. (author)

Genetic potentiality of indigenous rice genotypes from Eastern India with reference to submergence tolerance and deepwater traits

Directory of Open Access Journals (Sweden)

Sayani Goswami

2017-09-01

Full Text Available Submergence tolerance in rice varieties is crucial for maintaining stable yields in low land areas, where recurrence of flooding is a constant phenomenon during monsoon. We have conducted detailed physiological and genotyping studies of 27 rice genotypes and one wild rice relative, popularly grown in low land areas of the two major rice growing states of eastern India, West Bengal and Odisha with a focus on submergence tolerance traits and Sub1 loci. We found that these genotypes show varying degree (50–100% survival rate during post submergence recovery period, and high degree of polymorphism in the Sub1 linked rice microsatellite loci RM219 and RM7175. Detailed allelic diversity study of Sub1A loci suggests that rice varieties IR42, Panibhasha, Khoda and Kalaputia share a common allele that is different from FR13A, Keralasundari, Bhashakalmi, Kumrogore. Two other genotypes Meghi and Khoda shares both alleles of Sub1A loci (present in IR42 and FR13A groups in addition to a new variant. Detailed sequence analysis of the amplified product for the Sub1A loci from these genotypes showed several single nucleotide changes with respect to reference Oryza sativa Sub1A loci (DQ011598. Three rice genotypes (Meghi, Bhashakalmi and Keralasundari showed beneficial properties in relation to induced submergence stress and can be considered as valuable genetic source in context of utilization of natural rice genetic resources in breeding program for submergence tolerance.

Progress and challenges in improving the nutritional quality of rice (Oryza sativa L.).

Science.gov (United States)

Birla, Deep Shikha; Malik, Kapil; Sainger, Manish; Chaudhary, Darshna; Jaiwal, Ranjana; Jaiwal, Pawan K

2017-07-24

Rice is a staple food for more than 3 billion people in more than 100 countries of the world but ironically it is deficient in many bioavailable vitamins, minerals, essential amino- and fatty-acids and phytochemicals that prevent chronic diseases like type 2 diabetes, heart disease, cancers, and obesity. To enhance the nutritional and other quality aspects of rice, a better understanding of the regulation of the processes involved in the synthesis, uptake, transport, and metabolism of macro-(starch, seed storage protein and lipid) and micronutrients (vitamins, minerals and phytochemicals) is required. With the publication of high quality genomic sequence of rice, significant progress has been made in identification, isolation, and characterization of novel genes and their regulation for the nutritional and quality enhancement of rice. During the last decade, numerous efforts have been made to refine the nutritional and other quality traits either by using the traditional breeding with high through put technologies such as marker assisted selection and breeding, or by adopting the transgenic approach. A significant improvement in vitamins (A, folate, and E), mineral (iron), essential amino acid (lysine), and flavonoids levels has been achieved in the edible part of rice, i.e., endosperm (biofortification) to meet the daily dietary allowance. However, studies on bioavailability and allergenicity on biofortified rice are still required. Despite the numerous efforts, the commercialization of biofortified rice has not yet been achieved. The present review summarizes the progress and challenges of genetic engineering and/or metabolic engineering technologies to improve rice grain quality, and presents the future prospects in developing nutrient dense rice to save the everincreasing population, that depends solely on rice as the staple food, from widespread nutritional deficiencies.

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

Characterization and evaluation of three groups of rice upland of different origins through gamma-ray sensitivity

International Nuclear Information System (INIS)

Rodrigues, Luis Roberto Franco

2002-01-01

The characterization and evaluation of varieties of rice aid in the parents selection and in the increase of the genetic base of breeding programs. The present work was carried out to characterize and to evaluate three groups of rice upland (Oryza sativa L.) of different origins through gamma-ray sensitivity. Seeds of 84 varieties collected from Japan, Philippines and Brazil, were submitted to various doses of gamma-radiation and sown in wooden boxes. The experiment was conducted in 1991 at greenhouse according to randomized complete block design with three replications. Physiological effects caused by radiation in the M 1 generation, such as seed emergency, seedling height and survival rate, were determined and evaluated. The results showed significant differences of sensitivity to the radiation among three groups for all traits evaluated. (author)

Breeding elite japonica-type soft rice with high protein content ...

African Journals Online (AJOL)

STORAGESEVER

2009-01-19

Jan 19, 2009 ... hygromycin-resistant calli and regeneration of transgenic plants were performed ... Thirty rice seeds at the top of the ears of transgenic plants and the .... greater effect on the GC than the GT apart from its ability .... Cell Physiol.

Genetic Gain and Inbreeding from Genomic Selection in a Simulated Commercial Breeding Program for Perennial Ryegrass

Directory of Open Access Journals (Sweden)

Zibei Lin

2016-03-01

Full Text Available Genomic selection (GS provides an attractive option for accelerating genetic gain in perennial ryegrass ( improvement given the long cycle times of most current breeding programs. The present study used simulation to investigate the level of genetic gain and inbreeding obtained from GS breeding strategies compared with traditional breeding strategies for key traits (persistency, yield, and flowering time. Base population genomes were simulated through random mating for 60,000 generations at an effective population size of 10,000. The degree of linkage disequilibrium (LD in the resulting population was compared with that obtained from empirical studies. Initial parental varieties were simulated to match diversity of current commercial cultivars. Genomic selection was designed to fit into a company breeding program at two selection points in the breeding cycle (spaced plants and miniplot. Genomic estimated breeding values (GEBVs for productivity traits were trained with phenotypes and genotypes from plots. Accuracy of GEBVs was 0.24 for persistency and 0.36 for yield for single plants, while for plots it was lower (0.17 and 0.19, respectively. Higher accuracy of GEBVs was obtained for flowering time (up to 0.7, partially as a result of the larger reference population size that was available from the clonal row stage. The availability of GEBVs permit a 4-yr reduction in cycle time, which led to at least a doubling and trebling genetic gain for persistency and yield, respectively, than the traditional program. However, a higher rate of inbreeding per cycle among varieties was also observed for the GS strategy.

Genetic Gain and Inbreeding from Genomic Selection in a Simulated Commercial Breeding Program for Perennial Ryegrass.

Science.gov (United States)

Lin, Zibei; Cogan, Noel O I; Pembleton, Luke W; Spangenberg, German C; Forster, John W; Hayes, Ben J; Daetwyler, Hans D

2016-03-01

Genomic selection (GS) provides an attractive option for accelerating genetic gain in perennial ryegrass () improvement given the long cycle times of most current breeding programs. The present study used simulation to investigate the level of genetic gain and inbreeding obtained from GS breeding strategies compared with traditional breeding strategies for key traits (persistency, yield, and flowering time). Base population genomes were simulated through random mating for 60,000 generations at an effective population size of 10,000. The degree of linkage disequilibrium (LD) in the resulting population was compared with that obtained from empirical studies. Initial parental varieties were simulated to match diversity of current commercial cultivars. Genomic selection was designed to fit into a company breeding program at two selection points in the breeding cycle (spaced plants and miniplot). Genomic estimated breeding values (GEBVs) for productivity traits were trained with phenotypes and genotypes from plots. Accuracy of GEBVs was 0.24 for persistency and 0.36 for yield for single plants, while for plots it was lower (0.17 and 0.19, respectively). Higher accuracy of GEBVs was obtained for flowering time (up to 0.7), partially as a result of the larger reference population size that was available from the clonal row stage. The availability of GEBVs permit a 4-yr reduction in cycle time, which led to at least a doubling and trebling genetic gain for persistency and yield, respectively, than the traditional program. However, a higher rate of inbreeding per cycle among varieties was also observed for the GS strategy. Copyright © 2016 Crop Science Society of America.

Genomic prediction in a breeding program of perennial ryegrass

DEFF Research Database (Denmark)

Fé, Dario; Ashraf, Bilal; Greve-Pedersen, Morten

2015-01-01

We present a genomic selection study performed on 1918 rye grass families (Lolium perenne L.), which were derived from a commercial breeding program at DLF-Trifolium, Denmark. Phenotypes were recorded on standard plots, across 13 years and in 6 different countries. Variants were identified...... this set. Estimated Breeding Value and prediction accuracies were calculated trough two different cross-validation schemes: (i) k-fold (k=10); (ii) leaving out one parent combination at the time, in order to test for accuracy of predicting new families. Accuracies ranged between 0.56 and 0.97 for scheme (i....... A larger set of 1791 F2s were used as training set to predict EBVs of 127 synthetic families (originated from poly-crosses between 5-11 single plants) for heading date and crown rust resistance. Prediction accuracies were 0.93 and 0.57 respectively. Results clearly demonstrate considerable potential...

Effects of ridge tillage on photosynthesis and root characters of rice

Directory of Open Access Journals (Sweden)

Yao Yuan-zhi

2015-03-01

Full Text Available Rice (Oryza sativa L. is an important crop and breeding has not been able to improve yield. Root characteristics of hybrid rice 'Zhuliangyou 02' under conventional tillage and ridge tillage were studied in a Calcisols in Huaihua, China, from 2011 to 2013 to find better tillage methods to resolve massive water consumption, improve yield, and enhance productivity of agricultural labor for rice cultivation. Results showed ridge tillage increased photosynthetic parameters such as photosynthetic rate (P N, stomatal conductance (g s, and water use efficiency (WUE. It also significantly enhanced rice root number, root activity, and antioxidant enzyme activities; it also increased effective panicle number and actual yield by 22.12% and 15.18%, respectively, and enhanced aerenchymae during the early growth stage. Overall, ridge tillage could promote hybrid rice yields by enhancing root absorption, gas exchange, and reducing water consumption. It could be widely used in rice cultivation.

Tocopherol and tocotrienol contents of different varieties of rice in Malaysia.

Science.gov (United States)

Shammugasamy, Balakrishnan; Ramakrishnan, Yogeshini; Ghazali, Hasanah M; Muhammad, Kharidah

2015-03-15

The present study examined the contents of tocopherols and tocotrienols and their distribution in 58 different varieties of whole rice cultivated in Malaysia. The analytical method used was saponification of samples followed by dispersive liquid-liquid microextraction and reverse phase high-performance liquid chromatography. The total vitamin E contents of different varieties of whole rice ranged between 19.36 and 63.29 mg kg⁻¹. Contents of vitamin E isomers varied among rice varieties both within and between grain color groups. Black-pigmented rice showed significantly higher mean contents of α-tocopherol, β-tocopherol and α-tocotrienol than non-pigmented rice and red-pigmented rice. Red-pigmented rice had significantly lower mean contents of γ-tocotrienol and total vitamin E than non-pigmented rice. The mean contents of δ-tocotrienol and total vitamin E in non-pigmented rice, however, were similar to those in black-pigmented rice. γ-Tocotrienol was the predominant form of vitamin E isomer in all analyzed varieties. The Pearson correlations among vitamin E isomers and total vitamin E content of whole rice were also studied. This study provides information on vitamin E content of different rice varieties that would be beneficial for decision making in genetic breeding of bioactive compound-rich rice varieties. © 2014 Society of Chemical Industry.

Simultaneous Improvement and Genetic Dissection of Salt Tolerance of Rice (Oryza sativa L. by Designed QTL Pyramiding

Directory of Open Access Journals (Sweden)

Yunlong Pang

2017-07-01

Full Text Available Breeding of multi-stress tolerant rice varieties with higher grain yields is the best option to enhance the rice productivity of abiotic stresses prone areas. It also poses the greatest challenge to plant breeders to breed rice varieties for such stress prone conditions. Here, we carried out a designed QTL pyramiding experiment to develop high yielding “Green Super Rice” varieties with significantly improved tolerance to salt stress and grain yield. Using the F4 population derived from a cross between two selected introgression lines, we were able to develop six mostly homozygous promising high yielding lines with significantly improved salt tolerance and grain yield under optimal and/or saline conditions in 3 years. Simultaneous mapping using the same breeding population and tunable genotyping-by-sequencing technology, we identified three QTL affecting salt injury score and leaf chlorophyll content. By analyzing 32M SNP data of the grandparents and graphical genotypes of the parents, we discovered 87 positional candidate genes for salt tolerant QTL. According to their functional annotation, we inferred the most likely candidate genes. We demonstrated that designed QTL pyramiding is a powerful strategy for simultaneous improvement and genetic dissection of complex traits in rice.

Toward Genomics-Based Breeding in C3 Cool-Season Perennial Grasses

Science.gov (United States)

Talukder, Shyamal K.; Saha, Malay C.

2017-01-01

Most important food and feed crops in the world belong to the C3 grass family. The future of food security is highly reliant on achieving genetic gains of those grasses. Conventional breeding methods have already reached a plateau for improving major crops. Genomics tools and resources have opened an avenue to explore genome-wide variability and make use of the variation for enhancing genetic gains in breeding programs. Major C3 annual cereal breeding programs are well equipped with genomic tools; however, genomic research of C3 cool-season perennial grasses is lagging behind. In this review, we discuss the currently available genomics tools and approaches useful for C3 cool-season perennial grass breeding. Along with a general review, we emphasize the discussion focusing on forage grasses that were considered orphan and have little or no genetic information available. Transcriptome sequencing and genotype-by-sequencing technology for genome-wide marker detection using next-generation sequencing (NGS) are very promising as genomics tools. Most C3 cool-season perennial grass members have no prior genetic information; thus NGS technology will enhance collinear study with other C3 model grasses like Brachypodium and rice. Transcriptomics data can be used for identification of functional genes and molecular markers, i.e., polymorphism markers and simple sequence repeats (SSRs). Genome-wide association study with NGS-based markers will facilitate marker identification for marker-assisted selection. With limited genetic information, genomic selection holds great promise to breeders for attaining maximum genetic gain of the cool-season C3 perennial grasses. Application of all these tools can ensure better genetic gains, reduce length of selection cycles, and facilitate cultivar development to meet the future demand for food and fodder. PMID:28798766

Toward Genomics-Based Breeding in C3 Cool-Season Perennial Grasses

Directory of Open Access Journals (Sweden)

Shyamal K. Talukder

2017-07-01

Full Text Available Most important food and feed crops in the world belong to the C3 grass family. The future of food security is highly reliant on achieving genetic gains of those grasses. Conventional breeding methods have already reached a plateau for improving major crops. Genomics tools and resources have opened an avenue to explore genome-wide variability and make use of the variation for enhancing genetic gains in breeding programs. Major C3 annual cereal breeding programs are well equipped with genomic tools; however, genomic research of C3 cool-season perennial grasses is lagging behind. In this review, we discuss the currently available genomics tools and approaches useful for C3 cool-season perennial grass breeding. Along with a general review, we emphasize the discussion focusing on forage grasses that were considered orphan and have little or no genetic information available. Transcriptome sequencing and genotype-by-sequencing technology for genome-wide marker detection using next-generation sequencing (NGS are very promising as genomics tools. Most C3 cool-season perennial grass members have no prior genetic information; thus NGS technology will enhance collinear study with other C3 model grasses like Brachypodium and rice. Transcriptomics data can be used for identification of functional genes and molecular markers, i.e., polymorphism markers and simple sequence repeats (SSRs. Genome-wide association study with NGS-based markers will facilitate marker identification for marker-assisted selection. With limited genetic information, genomic selection holds great promise to breeders for attaining maximum genetic gain of the cool-season C3 perennial grasses. Application of all these tools can ensure better genetic gains, reduce length of selection cycles, and facilitate cultivar development to meet the future demand for food and fodder.

Leaf gas exchange and yield of three upland rice cultivars

Directory of Open Access Journals (Sweden)

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.

ROOT VEGETABLES, BREEDING TRENDS, RESULTS

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M. I. Fedorova

2017-01-01

Full Text Available The main advantage of root vegetables is their unique specificity and high economic importance. The benefits and medicinal properties of root vegetables being highly demanded by the market requirements to the commodity are highlighted in the article. The main directions of breeding program for root vegetable crops, including species of Apiaceae family with carrot, parsnips; Chenopodioideae family with red beet; Brassicaceae family with radish, Daikon, Raphanus sativus L. var. lobo Sazonova & Stank, turnip and rutabaga. Initial breeding accessions of carrot, red beet, radish, Daikon, Raphanus sativus L. var. lobo Sazonova & Stank, turnip and rutabaga have been selected out to be used for breeding program for heterosis. The mf and ms breeding lines were developed, and with the use of them the new gene pool was created. Variety supporting breeding program and methods were also proposed. 

Accuracy of Genomic Prediction in a Commercial Perennial Ryegrass Breeding Program

Directory of Open Access Journals (Sweden)

Dario Fè

2016-11-01

Full Text Available The implementation of genomic selection (GS in plant breeding, so far, has been mainly evaluated in crops farmed as homogeneous varieties, and the results have been generally positive. Fewer results are available for species, such as forage grasses, that are grown as heterogenous families (developed from multiparent crosses in which the control of the genetic variation is far more complex. Here we test the potential for implementing GS in the breeding of perennial ryegrass ( L. using empirical data from a commercial forage breeding program. Biparental F and multiparental synthetic (SYN families of diploid perennial ryegrass were genotyped using genotyping-by-sequencing, and phenotypes for five different traits were analyzed. Genotypes were expressed as family allele frequencies, and phenotypes were recorded as family means. Different models for genomic prediction were compared by using practically relevant cross-validation strategies. All traits showed a highly significant level of genetic variance, which could be traced using the genotyping assay. While there was significant genotype × environment (G × E interaction for some traits, accuracies were high among F families and between biparental F and multiparental SYN families. We have demonstrated that the implementation of GS in grass breeding is now possible and presents an opportunity to make significant gains for various traits.

Indica rice (Oryza sativa, BR29 and IR64).

Science.gov (United States)

Datta, Karabi; Datta, Swapan Kumar

2006-01-01

Rice is the world's most important food crop. Indica-type rice provides the staple food for more than half of the world population. To satisfy the growing demand of the ever-increasing population, more sustained production of indica-type rice is needed. In addition, because of the high per capita consumption of indica rice, improvement of any traits including its nutritive value may have a significant positive health outcome for the rice-consuming population. Rice yield productivity is greatly affected by different biotic stresses, like diseases and insect pests, and abiotic stresses like drought, cold, and salinity. Attempts to improve resistance in rice to these stresses by conventional breeding through introgression of traits have limited success owing to a lack of resistance germplasm in the wild relatives. Gene transfer technology with genes from other sources can be used to make rice plants resistant or tolerant to insect pests, diseases, and different environmental stresses. For improving the nutritional value of the edible endosperm part of the rice, genes for increasing iron, beta-carotene, or better quality protein can be introduced in rice plants by genetic engineering. Different crops have been transformed using various gene transfer methods, such as protoplast transformation, biolistic, and Agrobacterium-mediated transformation. This chapter describes the Agrobacterium-mediated transformation protocol for indica-type rice. The selectable marker genes used are hygromycin phosphotransferase (hpt), neomycin phosphotransferase (nptII), or phosphomannose isomerase (pmi), and, accordingly, the selection agents are hygromycin, kanamycin (G418), or mannose, respectively.

Genetic Variation and Association Analysis of the SSR Markers Linked to the Major Drought-Yield QTLs of Rice.

Science.gov (United States)

Tabkhkar, Narjes; Rabiei, Babak; Samizadeh Lahiji, Habibollah; Hosseini Chaleshtori, Maryam

2018-02-24

Drought is one of the major abiotic stresses, which hampers the production of rice worldwide. Informative molecular markers are valuable tools for improving the drought tolerance in various varieties of rice. The present study was conducted to evaluate the informative simple sequence repeat (SSR) markers in a diverse set of rice genotypes. The genetic diversity analyses of the 83 studied rice genotypes were performed using 34 SSR markers closely linked to the major quantitative trait loci (QTLs) of grain yield under drought stress (qDTYs). In general, our results indicated high levels of polymorphism. In addition, we screened these rice genotypes at the reproductive stage under both drought stress and nonstressful conditions. The results of the regression analysis demonstrated a significant relationship between 11 SSR marker alleles and the plant paddy weight under stressful conditions. Under the nonstressful conditions, 16 SSR marker alleles showed a significant correlation with the plant paddy weight. Finally, four markers (RM279, RM231, RM166, and RM231) demonstrated a significant association with the plant paddy weight under both stressful and nonstressful conditions. These informative-associated alleles may be useful for improving the crop yield under both drought stress and nonstressful conditions in breeding programs.

The Standardization of the Honeybee Colonies Evaluation Methodology, with Application in Honeybee Breeding Programs, in Romanian Conditions

OpenAIRE

Eliza Cauia; Adrian Siceanu; Silvia Patruica; Marian Bura; Agripina Sapcaliu; Maria Magdici

2010-01-01

It is well known that breeding is based on phenotypic and behavioural performance assessed at the level of each honeybee colony. By selection, the genes responsible for the desired characters have to be favoured, by evaluation and classification of all colonies involved in a breeding program. Generally, in the beekeeping practice, the most applied method of selection is the mass selection regarding the main objective- honey production. Some more elaborated programs use selection simultaneous ...

Assessment of genetic diversity in Indian rice germplasm (Oryza ...

Indian Academy of Sciences (India)

2013-12-11

Dec 11, 2013 ... 3Indian Agricultural Research Institute, Rice Breeding and Genetics Research Centre, Aduthurai 612 101, India ..... Govind Ballabh Pant University of Agriculture and Technology; IRRI, Inter- ..... 83–91, Arkansas Agricultural Experiment Station, ... Temnykh S., Park D. W., Ayres N., Cartinhour S., Hauck N.,.

Mapping QTLs for submergence tolerance during germination in rice

African Journals Online (AJOL)

STORAGESEVER

2008-08-04

Aug 4, 2008 ... Key words: Oryza sativa L, anaerobic germination, QTL analysis. INTRODUCTION. Two main ... The study was conducted at NG-01 greenhouse, Genome and. Mapping (GML), the .... ABC transporter family protein ..... differences of germination habits in rice seeds with special reference to plant breeding (in ...

ALTERNATIVES TO IMPROVE HYBRIDIZATION EFFICIENCY IN Eucalyptus BREEDING PROGRAMS

Directory of Open Access Journals (Sweden)

Roselaine Cristina Pereira

2002-01-01

Full Text Available Simple and quick hybridization procedures and ways to keep pollen grains viable for long periods are sought in plant breeding programs to provide greater work flexibility. The presentstudy was carried out to assess the efficiency of pollinations made shortly after flower emasculationand the viability of stored pollen from Eucalyptus camaldulensis and Eucalyptus urophylla clones cultivated in Northwestern Minas Gerais State. Controlled pollinations were carried out at zero, one,three, five and seven days after emasculation. Hybridization efficiency was assessed by thepercentage of viable fruits, number of seeds produced per fruit, percentage of viable seeds and also bycytological observation of the pollen development along the style. Flower buds from clones of the twospecies were collected close to anthesis to assess the viability of pollen grain storage. Pollen was thencollected and stored in a freezer (-18oC for 1, 2 and 3 months. Pollen assessed was carried out by invitro and in vivo germination tests. The efficiency of the pollinations varied with their delay and alsobetween species. The greatest pollination efficiency was obtained when they were carried out on thethird and fifth day after emasculation, but those performed simultaneously with emasculationproduced enough seeds to allow this practice in breeding programs. The decrease in pollen viabilitywith storage was not sufficiently significant to preclude the use of this procedure in artificialhybridization.

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

Evaluation of some mutant lines of rice induced by gamma radiation treatment 1. mean performance of rice mutants in M4 generation

International Nuclear Information System (INIS)

El-Banna, M.N.; El-Wakil, H.M.F.; Ebaid, R.A.; Sallam, R.A.

2009-01-01

Grains of eight rice mutants; SC 1, SC 6, RTY 1, RTY 3, HY 14, HYI 17, EH 4 and HYPI 22 were secured from Botany Department Faculty of Agriculture Cairo university. The procedures and the methodology for induction these mutants as well as the original mean performance of such mutants are presented else where; Sabbour, (1989) and Sabbour etal. (2002). Grains were sown (M4 generation) at the experimental farm in Itai EI-Baroud Agricultural Research Station Behaira Governorate Agricultural Research Center (ARC) in the summer season (2007). The mean performance of such mutants was studied during M4 generation. The most exciting results were as follows: the selected line SC 1 showed in M4 generation superior agronomic and yield traits. Sc 1 mutant line is not bred truly and it need more generations to reach stability. SC 6 in M4 generation showed considerable number of individuals scored low mean values toward the negative direction and lowering the overall trait mean performance. The rice lines RTY 1 and RTY 3 proved that, the average number of fertile tillers per plant of the selected lines maintained previously recorded mean values of M3 generation in M4. The traits showed significant differences among their progeny that recorded high CV% values as compared with those showed no significant differences. The rice lines HY 14 and HYI 17 showed a true breeding signs and no more breeding generations are required. Rice lines EH 4, showed a considerable reduction in number of days elapsed from date of cultivation till harvest. As, this mutant maintained 86.58 days till heading. Rice mutant line HYPI 22 did not bred truly for the original selected traits (high yield and high protein content) and it still need more generations of selection to reach considerable stability

Breeding of the nucleus sterile lines of rice by spaceflight inducement

International Nuclear Information System (INIS)

Guo Guangrong; Guo Feng; Cheng Legen; Zheng Shen

2004-01-01

A spaceflight in planet was arranged for the nucleus sterile line Peiai 64S in order to breed mutants. 60 Co-γ-rays irraidaiton is a comparison treatment. The whitenessed seedling rate of generation M 2 of the spaceflight treatments is much higher than of the 60 Co-γ-rays treatment. There is no remarkable difference in variance frequency of the seedling height and the bearing period of M 2 between the treatment. The whitenessed seedling rate and the sterile pollen rate of M 2 of both two treatments are remarkably higher than that with no treatment. The possible scale of increasing hetgerogamy rate, the genetic reasons for the increased outcrossing rate is pointed out on the purpose of breeding of the nucleus sterile lines. The risk on the application of the nucleus sterile lines with high hererogamy rate in production is also primarily evaluated. The results shows that spaceflight inducements is an effective way in breeding. (authors)

Promising mutant variety of rice evolved through gamma irradiation

International Nuclear Information System (INIS)

Prasad, S.C.; Sinha, S.K.

1980-01-01

Rice occupies a major share in crop production in the Chotanagpur plateau of Bihar State. Uplands are roughly 40% in area where traditional low yielding rice, known as ''gora'' is cultivated as directly sown crop. Despite introduction of high yielding rice varieties, gora group of rices continue to prevail. It is therefore desired to increase the productivity level of the gora rice by mutation breeding. One such mutant known as ''gora mutant'' was obtained through gamma irradiation (10 kR) of variety Brown gora. The maturity of both parent and mutant remaining constant (ie. 100 days), there is some improvement in other characteristics like plant height, tillering capacity and kernel character. The parent being tall, shy in tillering and red bold kernel, the mutant has dwarfish characteristics, profuse tillering habit and white kernel with fine grains. The yielding capacity of mutant derivative is 30-40% higher than the parent Brown gora. This variety is in pre-release stage, and the farmers have taken great liking for it. (author)

Genetic relatedness among indigenous rice varieties in the Eastern Himalayan region based on nucleotide sequences of the Waxy gene.

Science.gov (United States)

Choudhury, Baharul I; Khan, Mohammed L; Dayanandan, Selvadurai

2014-12-29

Indigenous rice varieties in the Eastern Himalayan region of Northeast India are traditionally classified into sali, boro and jum ecotypes based on geographical locality and the season of cultivation. In this study, we used DNA sequence data from the Waxy (Wx) gene to infer the genetic relatedness among indigenous rice varieties in Northeast India and to assess the genetic distinctiveness of ecotypes. The results of all three analyses (Bayesian, Maximum Parsimony and Neighbor Joining) were congruent and revealed two genetically distinct clusters of rice varieties in the region. The large group comprised several varieties of sali and boro ecotypes, and all agronomically improved varieties. The small group consisted of only traditionally cultivated indigenous rice varieties, which included one boro, few sali and all jum varieties. The fixation index analysis revealed a very low level of differentiation between sali and boro (F(ST) = 0.005), moderate differentiation between sali and jum (F(ST) = 0.108) and high differentiation between jum and boro (F(ST) = 0.230) ecotypes. The genetic relatedness analyses revealed that sali, boro and jum ecotypes are genetically heterogeneous, and the current classification based on cultivation type is not congruent with the genetic background of rice varieties. Indigenous rice varieties chosen from genetically distinct clusters could be used in breeding programs to improve genetic gain through heterosis, while maintaining high genetic diversity.

Strategies for Selecting Crosses Using Genomic Prediction in Two Wheat Breeding Programs.

Science.gov (United States)

Lado, Bettina; Battenfield, Sarah; Guzmán, Carlos; Quincke, Martín; Singh, Ravi P; Dreisigacker, Susanne; Peña, R Javier; Fritz, Allan; Silva, Paula; Poland, Jesse; Gutiérrez, Lucía

2017-07-01

The single most important decision in plant breeding programs is the selection of appropriate crosses. The ideal cross would provide superior predicted progeny performance and enough diversity to maintain genetic gain. The aim of this study was to compare the best crosses predicted using combinations of mid-parent value and variance prediction accounting for linkage disequilibrium (V) or assuming linkage equilibrium (V). After predicting the mean and the variance of each cross, we selected crosses based on mid-parent value, the top 10% of the progeny, and weighted mean and variance within progenies for grain yield, grain protein content, mixing time, and loaf volume in two applied wheat ( L.) breeding programs: Instituto Nacional de Investigación Agropecuaria (INIA) Uruguay and CIMMYT Mexico. Although the variance of the progeny is important to increase the chances of finding superior individuals from transgressive segregation, we observed that the mid-parent values of the crosses drove the genetic gain but the variance of the progeny had a small impact on genetic gain for grain yield. However, the relative importance of the variance of the progeny was larger for quality traits. Overall, the genomic resources and the statistical models are now available to plant breeders to predict both the performance of breeding lines per se as well as the value of progeny from any potential crosses. Copyright © 2017 Crop Science Society of America.

Nuclear and chloroplast diversity and phenotypic distribution of rice (Oryza sativa L.) germplasm from the democratic people’s republic of Korea (DPRK; North Korea)

Science.gov (United States)

2014-01-01

Background Rice accounts for 43% of staple food production in the Democratic People’s Republic of Korea (DPRK). The most widely planted rice varieties were developed from a limited number of ancestral lines that were repeatedly used as parents in breeding programs. However, detailed pedigrees are not publicly available and little is known about the genetic, phenotypic, and geographical variation of DPRK varieties. Results We evaluated 80 O. sativa accessions from the DPRK, consisting of 67 improved varieties and 13 landraces. Based on nuclear SSR analysis, we divide the varieties into two genetic groups: Group 1 corresponds to the temperate japonica subpopulation and represents 78.75% of the accessions, while Group 2 shares recent ancestry with indica varieties. Interestingly, members of Group 1 are less diverse than Group 2 at the nuclear level, but are more diverse at the chloroplast level. All Group 2 varieties share a single Japonica maternal-haplotype, while Group 1 varieties trace maternal ancestry to both Japonica and Indica. Phenotypically, members of Group 1 have shorter grains than Group 2, and varieties from breeding programs have thicker and wider grains than landraces. Improved varieties in Group 1 also show similar and/or better levels of cold tolerance for most traits, except for spikelet number per panicle. Finally, geographic analysis demonstrates that the majority of genetic variation is located within regions that have the most intensive rice cultivation, including the Western territories near the capital city Pyungyang. This is consistent with the conscious and highly centralized role of human selection in determining local dispersion patterns of rice in the DPRK. Conclusions Diversity studies of DPRK rice germplasm revealed two genetic groups. The most widely planted group has a narrow genetic base and would benefit from the introduction of new genetic variation from cold tolerant landraces, wild accessions, and/or cultivated gene pools to

Linkage Mapping of Stem Saccharification Digestibility in Rice.

Directory of Open Access Journals (Sweden)

Bohan Liu

Full Text Available Rice is the staple food of almost half of the world population, and in excess 90% of it is grown and consumed in Asia, but the disposal of rice straw poses a problem for farmers, who often burn it in the fields, causing health and environmental problems. However, with increased focus on the development of sustainable biofuel production, rice straw has been recognized as a potential feedstock for non-food derived biofuel production. Currently, the commercial realization of rice as a biofuel feedstock is constrained by the high cost of industrial saccharification processes needed to release sugar for fermentation. This study is focused on the alteration of lignin content, and cell wall chemotypes and structures, and their effects on the saccharification potential of rice lignocellulosic biomass. A recombinant inbred lines (RILs population derived from a cross between the lowland rice variety IR1552 and the upland rice variety Azucena with 271 molecular markers for quantitative trait SNP (QTS analyses was used. After association analysis of 271 markers for saccharification potential, 1 locus and 4 pairs of epistatic loci were found to contribute to the enzymatic digestibility phenotype, and an inverse relationship between reducing sugar and lignin content in these recombinant inbred lines was identified. As a result of QTS analyses, several cell-wall associated candidate genes are proposed that may be useful for marker-assisted breeding and may aid breeders to produce potential high saccharification rice varieties.

Production system and participatory identification of breeding objective traits for indigenous goat breeds of Uganda

NARCIS (Netherlands)

Onzima, R.B.; Gizaw, S.; Kugonza, D.R.; Arendonk, van J.A.M.; Kanis, E.

2018-01-01

The success of breeding programs in improving indigenous livestock breeds in Uganda has hitherto been limited due to lack of involvement of the key stakeholders. Thus, participatory approaches are being promoted for designing community based improvement programs. The aim of this study was to

Production system and participatory identification of breeding objective traits for indigenous goat breeds of Uganda

NARCIS (Netherlands)

Onzima, R.B.; Gizaw, S.; Kugonza, D.R.; Arendonk, van J.A.M.; Kanis, E.

2017-01-01

The success of breeding programs in improving indigenous livestock breeds in Uganda has hitherto been limited due to lack of involvement of the key stakeholders. Thus, participatory approaches are being promoted for designing community based improvement programs. The aim of this study was to

RNAi-mediated resistance to rice black-streaked dwarf virus in transgenic rice.

Science.gov (United States)

Ahmed, Mohamed M S; Bian, Shiquan; Wang, Muyue; Zhao, Jing; Zhang, Bingwei; Liu, Qiaoquan; Zhang, Changquan; Tang, Shuzhu; Gu, Minghong; Yu, Hengxiu

2017-04-01

Rice black-streaked dwarf virus (RBSDV), a member of the genus Fijivirus in the family Reoviridae, causes significant economic losses in rice production in China and many other Asian countries. Development of resistant varieties by using conventional breeding methods is limited, as germplasm with high level of resistance to RBSDV have not yet been found. One of the most promising methods to confer resistance against RBSDV is the use of RNA interference (RNAi) technology. RBSDV non-structural protein P7-2, encoded by S7-2 gene, is a potential F-box protein and involved in the plant-virus interaction through the ubiquitination pathway. P8, encoded by S8 gene, is the minor core protein that possesses potent active transcriptional repression activity. In this study, we transformed rice calli using a mini-twin T-DNA vector harboring RNAi constructs of the RBSDV genes S7-2 or S8, and obtained plants harboring the target gene constructs and the selectable marker gene, hygromycin phosphotransferase (HPT). From the offspring of these transgenic plants, we obtained selectable marker (HPT gene)-free plants. Homozygous T 5 transgenic lines which harbored either S7-2-RNAi or S8-RNAi exhibited high level resistance against RBSDV under field infection pressure from indigenous viruliferous small brown planthoppers. Thus, our results showed that RNA interference with the expression of S7-2 or S8 genes seemed an effective way to induce high level resistance in rice against RBSD disease.

Diversity and population structure of red rice germplasm in Bangladesh.

Science.gov (United States)

Islam, M Z; Khalequzzaman, M; Prince, M F R K; Siddique, M A; Rashid, E S M H; Ahmed, M S U; Pittendrigh, B R; Ali, M P

2018-01-01

While the functionality and healthy food value of red rice have increased its popularity, such that market demand for it is expected to rise, most strains suffer from low grain yield. To perform diversity and population structure analyses of red rice germplasm, therefore, becomes essential for improving yields for commercial production. In this study, fifty red rice germplasm from the Bangladesh Rice Research Institute (BRRI) genebank were characterized both morphologically and genetically using fifty simple sequence repeat (SSR) markers. Overall, 162 alleles were detected by the markers with the detected allele number varying from two to seven. Additionally, 22 unique alleles were identified for use as a germplasm diagnostic tool. The highest and lowest polymorphic information content (PIC) indices were 0.75 and 0.04 found in markers RM282 and RM304, respectively, and genetic diversity was moderate, varying from 0.05 to 0.78 (average: 0.35). While phylogenetic cluster analysis of the fifteen distance-based agro-morphological traits divided the germplasm into five clusters (I, II, III, IV and V), a similar SSR analysis yielded only three major groups (I, II, and III), and a model-based population structure analysis yielded four (A, B, C and D). Both principal component and neighbors joining tree analysis from the population structure method showed the tested germplasm as highly diverse in structure. Moreover, an analysis of molecular variance (AMOVA), as well as a pairwise FST analysis, both indicated significant differentiation (ranging from 0.108 to 0.207) among all pairs of populations, suggesting that all four population structure groups differed significantly. Populations A and D were the most differentiated from each other by FST. Findings from this study suggest that the diverse germplasm and polymorphic trait-linked SSR markers of red rice are suitable for the detection of economically desirable trait loci/genes for use in future molecular breeding programs.

Major QTLs Control Resistance to Rice Hoja Blanca Virus and Its Vector Tagosodes orizicolus

Science.gov (United States)

Romero, Luz E.; Lozano, Ivan; Garavito, Andrea; Carabali, Silvio J.; Triana, Monica; Villareal, Natalia; Reyes, Luis; Duque, Myriam C.; Martinez, César P.; Calvert, Lee; Lorieux, Mathias

2013-01-01

Rice hoja blanca (white leaf) disease can cause severe yield losses in rice in the Americas. The disease is caused by the rice hoja blanca virus (RHBV), which is transmitted by the planthopper vector Tagosodes orizicolus. Because classical breeding schemes for this disease rely on expensive, time-consuming screenings, there is a need for alternatives such as marker-aided selection. The varieties Fedearroz 2000 and Fedearroz 50, which are resistant to RHBV and to the feeding damage caused by T. orizicolus, were crossed with the susceptible line WC366 to produce segregating F2:3 populations. The F3 families were scored for their resistance level to RHBV and T. orizicolus. The F2:3 lines of both crosses were genotyped using microsatellite markers. One major QTL on the short arm of chromosome 4 was identified for resistance to RHBV in the two populations. Two major QTL on chromosomes 5 and 7 were identified for resistance to T. orizicolus in the Fd2000 × WC366 and Fd50 × WC366 crosses, respectively. This comparative study using two distinct rice populations allowed for a better understanding of how the resistance to RHBV and its vector are controlled genetically. Simple marker-aided breeding schemes based on QTL information can be designed to improve rice germplasm to reduce losses caused by this important disease. PMID:24240781

THE USE THE GENETICALLY DIFFICULTLY INHERITED TRAIT OF PURPLE ROOT COLOR IN BREEDING PROGRAM FOR THE COMPLICATED TRAIT IN RADISH

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S. V. Ugarova

2017-01-01

Full Text Available The understanding the nature of trait inheritance in any crops is that determines the quality of results in breeding program. According to reference on previous publication, it is known that phenotypic manifestation of purple root color in radish was caused by regulatory interrelationship mechanisms of genetic control that is difficult to be used directly in breeding program. From literature sources and on the basis of their own research work the authors have proven the practice to maintain the trait in generations, and implementations of development of purple radish breeding accessions have been presented. At first stage of breeding program the selection of initial breeding accessions was carried out, where 14 varieties (red x white were regarded on the basis of top-crosses to obtain F1 and F2 progenies to be analyzed. Thus, four best combinations from crossing were chosen with 100% of hybridity. Through analysis of hybrids for individual progenies the hybrid population F1 of radish ‘Konfeti’ with different root colors was developed. As result of the individual inbreeding selection on seed plants with pigmented stems and the colored flower rim, the stable breeding accession with purple root was obtained. Thus, in breeding practice in radish it was succeeded to obtain the stably inheriting purple root color in radish accessions, variety ‘Siniiy Iniey’. 

Integrated analysis for genotypic adaptation in rice | Das | African ...

African Journals Online (AJOL)

Integrated analysis for genotypic adaptation in rice. S Das, RC Misra, MC Pattnaik, SK Sinha. Abstract. Development of varieties with high yield potential coupled with wide adaptability is an important plant breeding objective. The presence of genotype by environment (GxE) interaction plays a crucial role in determining the ...

Estimation of genetic parameters for growth traits in a breeding program for rainbow trout (Oncorhynchus mykiss) in China.

Science.gov (United States)

Hu, G; Gu, W; Bai, Q L; Wang, B Q

2013-04-26

Genetic parameters and breeding values for growth traits were estimated in the first and, currently, the only family selective breeding program for rainbow trout (Oncorhynchus mykiss) in China. Genetic and phenotypic data were collected for growth traits from 75 full-sibling families with a 2-generation pedigree. Genetic parameters and breeding values for growth traits of rainbow trout were estimated using the derivative-free restricted maximum likelihood method. The goodness-of-fit of the models was tested using Akaike and Bayesian information criteria. Genetic parameters and breeding values were estimated using the best-fit model for each trait. The values for heritability estimating body weight and length ranged from 0.20 to 0.45 and from 0.27 to 0.60, respectively, and the heritability of condition factor was 0.34. Our results showed a moderate degree of heritability for growth traits in this breeding program and suggested that the genetic and phenotypic tendency of body length, body weight, and condition factor were similar. Therefore, the selection of phenotypic values based on pedigree information was also suitable in this research population.

In planta assay of hygromycin susceptibility and mutant screening in rice at heading stage

International Nuclear Information System (INIS)

Fu Haowei; Li Youfa; Ma Xinghua; Shen Shengquan; Shu Xiaoli; Shu Qingyao; Chen Yang

2012-01-01

Cells and tissue of plants carrying the hygromycin phosphotransferase gene (HPT) are tolerant to antibiotic hygromycin and hence become the common selection gene for genetic transformation of crop plants, particularly monocots. The present study aimed at establishing a rapid method for in planta screening of hygromycin tolerant plants in transgenic breeding. At heading stage transgenic and conventional rice plants were sprayed with hygromycin solutions of different concentrations (25 ∼ 100 mg/L) and toxic symptoms were observed in the following days. It was observed that yellow-brown necrotic spots appeared in the leaves and grains of conventional rice varieties after foliar spraying of 50 mg/L hygromycin, and the more spots were occurred with the higher hygromycin solution. There were 21.1 and 19.2 spots per cm 2 on flag leaves of indica varieties Jiayou 99 and C10, respectively; while 27.6% and 23.5% grains were yellow-brown in the varieties, respectively. The corresponding data for two japonica varieties Jiayou 5 and R5 were 11.8 and 10.7 for leave spots and 11.2% and 11.6% for yellow-brown grains, respectively. These results indicated that the two indica varieties are more sensitive to hygromycin than the two japonica varieties. In the treatment of hygromycin with above levels, the transgenic rice line KMD1 with the HPT gene showed no toxic symptoms on leaf or panicles. The γ-rays treated M 2 population of KMD1 was sprayed with 100 mg/L hygromycin solution at heading stage and 42 plants were screened out with toxic symptoms in leaves and panicles form 120000 plants. Among the 42 hygromycin susceptible plants, 14 plants with leaves available for in vitro feeding assay were subjected to the feeding of rice striped steam borers [Chilo supperssalis (Walker)] and all showed high resistance. The above results showed that spraying of 100 mg/L hygromycin solution at heading stage would lead to visually apparent toxic symptoms in susceptibility rice plants and hence

Effects of an injury and illness prevention program on occupational safety behaviors among rice farmers in Nakhon Nayok Province, Thailand

Directory of Open Access Journals (Sweden)

Santaweesuk S

2014-03-01

Full Text Available Sapsatree Santaweesuk,1,2 Robert S Chapman,1 Wattasit Siriwong1,3 1College of Public Health Sciences, Chulalongkorn University, Bangkok, Thailand; 2Srinakarinwirot University Ongkharak Campus, Nakhon Nayok, Thailand; 3Thai Fogarty ITREOH Center, Chulalongkorn University, Bangkok, Thailand Abstract: The objective of this study was to determine the effects of an Injury and Illness Prevention (IIP program intervention on occupational safety behavior among rice farmers in Nakhon Nayok province, Thailand. This was a quasi-experimental study in an intervention group and a control group. It was carried out in two rice farming communities, in which most people are rice farmers with similar socio-demographic characteristics. Multistage sampling was employed, selecting one person per rice farming household. The intervention group was 62 randomly selected rice farmers living in a rural area; another 55 rice farmers served as the control group. A structured face-to-face interview questionnaire was administered to participants to evaluate their safety behaviors in four areas: equipment use, pesticide use, ergonomics, and working conditions. The 2-week intervention program consisted of four elements: 1 health education, 2 safety inspection, 3 safety communication, and 4 health surveillance. Data were collected at baseline and 4 months after the intervention (follow-up. We used a general linear model repeated-measures analysis of variance to assess the mean difference between baseline and follow-up occupational safety behavior points between the intervention and control groups. Pesticide safety behaviors significantly increased in the intervention group compared with the control group. Ergonomics and working conditions points also increased in the intervention group, but not significantly so. The equipment use score decreased in the intervention group. It is necessary to identify and develop further measures to improve occupational safety behaviors. Some

Not just a grain of rice: the quest for quality

NARCIS (Netherlands)

Fizgerald, M.A.; McCouch, S.R.; Hall, R.D.

2009-01-01

A better understanding of the factors that contribute to the overall grain quality of rice (Oryza sativa) will lay the foundation for developing new breeding and selection strategies for combining high quality, with high yield. This is necessary to meet the growing global demand for high quality

Plant Breeding and Genetics Newsletter, No. 32, January 2014

International Nuclear Information System (INIS)

2014-01-01

One major event this last half of 2013 was the success story of the IAEA interregional TC project INT/5/150 'Responding to the Transboundary Threat of Wheat Black Stem Rust (Ug99)'. Results have been achieved in record time; the project was started in 2009, and by mid 2013, two advanced mutant lines, resistant to the most virulent strains of wheat black stem rust (Ug99), successfully passed the national performance trials in Kenya and are ready for commercial release. A Regional Training Course was organized at IRRI (The Philippines) in the framework of regional TC project RAS/5/065 'Supporting Climate-Proofing Rice Production Systems (CRiPS) Based on Nuclear Applications'. By joining efforts, the IAEA, FAO and IRRI aim to ensure that rice scientists are acquainted with the most recent plant breeding and phenotyping approaches, allowing them to address future threats to food security stemming from climate change and other stress factors. The project also aims to act as a platform for future collaboration in rice production. This second half of the year was also the period of 'first timers'. For the first time, Lesotho is using mutation breeding techniques in potato, sweet potato and amaranth. A fellow is being introduced to these techniques at the Plant Breeding and Genetics Laboratory (PBGL) in Seibersdorf, Austria. Similarly we are supporting and nurturing the first steps of national mutation breeding programmes in Oman, Palestine, Qatar and Saudi Arabia. Another cause for excitement is the ReNuAL project: the Seibersdorf Laboratories will be upgraded and renovated, including the FAO/IAEA Agriculture and Biotechnology Laboratories. This is a huge project with many logistical challenges, which are being met with vigour and personal investment in time and energy by our staff. Our guidance in this endeavour is 'fit-forpurpose to the Member States' in the future. IAEA Member States adopted a resolution to support this initiative, and we are now seeking financial and

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...

Development of inter-specific chromosomes segment substitution libraries (CSSL) in rice

Science.gov (United States)

Six libraries of inter-specific Chromosome Segment Substitution Lines (CSSLs) of rice are being developed as pre-breeding materials and genetic stocks. Three accessions of O. rufipogon were selected as donors, based on phylogenetic, geographical and morphological divergence, and crossed with two rec...

Genomic Selection Accuracy using Multifamily Prediction Models in a Wheat Breeding Program

Directory of Open Access Journals (Sweden)

Elliot L. Heffner

2011-03-01

Full Text Available Genomic selection (GS uses genome-wide molecular marker data to predict the genetic value of selection candidates in breeding programs. In plant breeding, the ability to produce large numbers of progeny per cross allows GS to be conducted within each family. However, this approach requires phenotypes of lines from each cross before conducting GS. This will prolong the selection cycle and may result in lower gains per year than approaches that estimate marker-effects with multiple families from previous selection cycles. In this study, phenotypic selection (PS, conventional marker-assisted selection (MAS, and GS prediction accuracy were compared for 13 agronomic traits in a population of 374 winter wheat ( L. advanced-cycle breeding lines. A cross-validation approach that trained and validated prediction accuracy across years was used to evaluate effects of model selection, training population size, and marker density in the presence of genotype × environment interactions (G×E. The average prediction accuracies using GS were 28% greater than with MAS and were 95% as accurate as PS. For net merit, the average accuracy across six selection indices for GS was 14% greater than for PS. These results provide empirical evidence that multifamily GS could increase genetic gain per unit time and cost in plant breeding.

Influence of Climate Factors on Rice Yields in Cambodia

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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.

One size fits all? : optimization of rainbow trout breeding program under diverse preferences and genotype-by-environment interaction

NARCIS (Netherlands)

Sae-Lim, P.

2013-01-01

Global fish breeders distribute improved animal material to several continents to be farmed under diverse environments, and for very different market conditions. When establishing a global breeding program, there is a need to assess whether or not a single breeding objective satisfies the

Scaling up Intermittent Rice Irrigation for Malaria Control on the ...

International Development Research Centre (IDRC) Digital Library (Canada)

The water used for rice farming is a breeding ground for malarial mosquitoes that ... climate variability and change are threatening the sources of irrigation water and ... skills (farmer-to-farmer agricultural extension); - assess and document social, ... Adaptation strategies for two Colombian cities were discussed at ADAPTO's ...

Estimation of genetic diversity in rice ( Oryza sativa L. ) genotypes ...

African Journals Online (AJOL)

Thirty rice genotypes comprising land races, pure lines, somaclones, breeding lines and varieties specifically adapted to costal saline environments were characterized by SSR markers and morphological characters in this study. Out of 35 primers of SSR markers, 28 were found to be polymorphic. The PIC value ranged ...

Tracking the Genetic Stability of a Honey Bee (Hymenoptera: Apidae) Breeding Program With Genetic Markers.

Science.gov (United States)

Bourgeois, Lelania; Beaman, Lorraine

2017-08-01

A genetic stock identification (GSI) assay was developed in 2008 to distinguish Russian honey bees from other honey bee stocks that are commercially produced in the United States. Probability of assignment (POA) values have been collected and maintained since the stock release in 2008 to the Russian Honey Bee Breeders Association. These data were used to assess stability of the breeding program and the diversity levels of the contemporary breeding stock through comparison of POA values and genetic diversity parameters from the initial release to current values. POA values fluctuated throughout 2010-2016, but have recovered to statistically similar levels in 2016 (POA(2010) = 0.82, POA(2016) = 0.74; P = 0.33). Genetic diversity parameters (i.e., allelic richness and gene diversity) in 2016 also remained at similar levels when compared to those in 2010. Estimates of genetic structure revealed stability (FST(2009/2016) = 0.0058) with a small increase in the estimate of the inbreeding coefficient (FIS(2010) = 0.078, FIS(2016) = 0.149). The relationship among breeding lines, based on genetic distance measurement, was similar in 2008 and 2016 populations, but with increased homogeneity among lines (i.e., decreased genetic distance). This was expected based on the closed breeding system used for Russian honey bees. The successful application of the GSI assay in a commercial breeding program demonstrates the utility and stability of such technology to contribute to and monitor the genetic integrity of a breeding stock of an insect species. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

Resistance Genes in Global Crop Breeding Networks.

Science.gov (United States)

Garrett, K A; Andersen, K F; Asche, F; Bowden, R L; Forbes, G A; Kulakow, P A; Zhou, B

2017-10-01

Resistance genes are a major tool for managing crop diseases. The networks of crop breeders who exchange resistance genes and deploy them in varieties help to determine the global landscape of resistance and epidemics, an important system for maintaining food security. These networks function as a complex adaptive system, with associated strengths and vulnerabilities, and implications for policies to support resistance gene deployment strategies. Extensions of epidemic network analysis can be used to evaluate the multilayer agricultural networks that support and influence crop breeding networks. Here, we evaluate the general structure of crop breeding networks for cassava, potato, rice, and wheat. All four are clustered due to phytosanitary and intellectual property regulations, and linked through CGIAR hubs. Cassava networks primarily include public breeding groups, whereas others are more mixed. These systems must adapt to global change in climate and land use, the emergence of new diseases, and disruptive breeding technologies. Research priorities to support policy include how best to maintain both diversity and redundancy in the roles played by individual crop breeding groups (public versus private and global versus local), and how best to manage connectivity to optimize resistance gene deployment while avoiding risks to the useful life of resistance genes. [Formula: see text] Copyright © 2017 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

The road to micronutrient biofortification of rice:Progress and prospects

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Khurram eBashir

2013-02-01

Full Text Available Biofortification (Increasing the contents of vitamins and minerals through plant breeding or biotechnology of food crops with micronutrient elements has the potential to combat widespread micronutrient deficiencies in humans. Rice (Oryza sativa L. feeds more than half of the world’s population and is used as a staple food in many parts of Asia. As in other plants, micronutrient transport in rice is controlled at several stages, including uptake from soil, transport from root to shoot, careful control of subcellular micronutrient transport, and finally, and most importantly, transport to seeds. To enhance micronutrient accumulation in rice seeds, we need to understand and carefully regulate all of these processes. During the last decade, numerous attempts such as increasing the contents/expression of genes encoding metal chelators (mostly phytosiderophores and metal transporters; overexpressing Fe storage protein ferritin and phytase were successfully undertaken to significantly increase the micronutrient content of rice. However, despite the rapid progress in biofortification of rice, the commercialization of biofortified crops has not yet been achieved. Here, we briefly review the progress in biofortification of rice with micronutrient elements (Fe, Zn and Mn and discuss future prospects to mitigate widespread micronutrient deficiencies in humans.

Conservation and diversification of QTGs involved in photoperiodic flowering between rice and Arabidopsis

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Kazuki eMatsubara

2014-05-01

Full Text Available Flowering time in rice (Oryza sativa L. is determined primarily by daylength (photoperiod, and natural variation in flowering time is due to quantitative trait loci involved in photoperiodic flowering. To date, genetic analysis of natural variants in rice flowering time has resulted in the positional cloning of at least 12 quantitative trait genes (QTGs, including our recently cloned QTGs, Hd17 and Hd16. The QTGs have been assigned to specific photoperiodic flowering pathways. Among them, 9 have homologs in the Arabidopsis genome, whereas it was evident that there are differences in the pathways between rice and Arabidopsis, such that the rice Ghd7–Ehd1–Hd3a/RFT1 pathway modulated by Hd16 is not present in Arabidopsis. In this review, we describe QTGs underlying natural variation in rice flowering time. Additionally, we discuss the implications of the variation in adaptive divergence and its importance in rice breeding.

Maintaining or Abandoning African Rice: Lessons for Understanding Processes of Seed Innovation

NARCIS (Netherlands)

Teeken, B.W.E.; Nuijten, H.A.C.P.; Temudo, M.P.; Okry, F.; Mokuwa, G.A.; Struik, P.C.; Richards, P.

2012-01-01

Rice breeding and crop research predominantly emphasize adaptation to ecological conditions. Based on qualitative and quantitative research conducted between 2000 and 2012 we show how ecological factors, combined with socioeconomic variables, cultural norms and values, shape the use and development

Effects of Soil Veterinary Antibiotics Pollution on Rice Growth

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XU Qiu-tong

2016-01-01

Full Text Available To understand the potential effect of soil veterinary antibiotics pollution on the growth of rice, a main food crop in China, oxytetracycline which was used widely in livestock and poultry breeding was selected to test the effects of different levels of soil antibiotics pollution on growth and yield of rice plant at both seedling and growth periods. Relationship between oxytetracycline accumulated in different organs of rice plant and oxytetracycline pollution levels in the soil was characterized. The results showed that the effects of soil oxytetracycline pollution on rice growth mainly occurred at the seedling stage, and the effect on the underground part was obviously greater than the above-ground part of rice. Significant negative effects on biomass of the underground part of rice, root activity, and chlorophyll content and oxidase activity of the leave at the seedling stage were found when soil oxytetracycline pollution concentrations was over 30 mg·kg-1. The consequence from the impact of soil oxytetracycline pollution on rice seedling could be extended to the whole growth period of the plant, which could reduce the number of tiller and rice yield. Oxytetracycline accumulated in various organs of rice plant was in the sequence of root> leaf> stem> grain. Rice roots had low capacity to uptake oxytetracycline from the soil, the transfer capacity of oxytetracycline from the roots to leaf, stem, and grain was also weak. Considering the low oxytetracycline pollution levels in most of current actual farmland soils (less than 10 mg·kg-1 and lower accumulation character of oxytetracycline in the grain, it is thought that the direct damage of soil oxytetracycline pollution on rice production is small.

Population and Habitat Objectives for Breeding Shorebirds in California’s Central Valley

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Khara M. Strum

2017-03-01

Full Text Available http://escholarship.org/uc/item/2836q0qgThe Central Valley of California provides important breeding habitat to numerous species of wetland-dependent birds, despite the loss of over 90% of naturally occurring wetlands. A majority of shorebirds breeding in this region rely on shallow-flooded habitat adjacent to sparsely vegetated uplands as provided by rice (Oryza sativa, managed wetlands, and other habitats. We estimated the current extent of potential breeding shorebird habitat provided by rice and managed permanent and semi-permanent wetlands in each of four major planning regions of the Central Valley, and estimated the average breeding densities and current population sizes of two species of shorebirds: the Black-Necked Stilt (Himantopus mexicanus and American Avocet (Recurvirostra americana. Using a population status framework based on principles of conservation biology, we estimated that stilt populations are small (<10,000 individuals or very small (<1,000 individuals in three of the four planning regions, and avocet populations are small or very small in all four planning regions. We then used the framework to define long-term (100-year population objectives for stilts, avocets, and a third species, Killdeer (Charadrius vociferous, designed to meet our long-term conservation goal of supporting self-sustaining, genetically robust, and resilient populations of breeding shorebirds in the Central Valley. We also estimated the long-term species’ density and wetland habitat objectives necessary to achieve the population objectives for all three species. The corresponding short-term (10-year conservation objectives are to restore semi-permanent wetlands to provide an additional 11,537 ha (28,508 ac of habitat for breeding shorebirds (by planning region: 2,842 ha in Sacramento, 2,897 ha in Yolo–Delta, 2,943 ha in San Joaquin, and 2,855 ha in Tulare, and to enhance existing habitat to support density objectives. Our approach provides a

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)

Improvement of rice anther culture and application of the technique in mutation breeding

International Nuclear Information System (INIS)

Chen Qiufang; Wang Cailian; Lu Yimei; Jin Wei

2001-01-01

The ability of callus formation and green plant regeneration was very different for different rice type and varieties in anther culture. The differentiation and regeneration of green plants were obviously improved when the rice anthers at about 30 d after culture on induction medium were irradiated with 20 Gy of γ-rays and calli were cultured on the differentiation medium containing 30 mg/L colchicines. The stimulation effect of γ-irradiation combined with colchicines was much better than that of their single use. Mutation frequency and selective efficiency in M 2 were obviously increased by application of the technique

Cooking and Eating Quality of Rice Yellow Mottle Virus Resistant ...

African Journals Online (AJOL)

Cooking and Eating Quantity of Rice Yellow Mottle 195 varieties often out compete introduced varieties on local markets; even though the former have lower yield potential. Breeding work incorporating grain quality was started in 1972 with the aim of developing varieties which combine high grain yield and grain quality ...

Gene, protein and network of male sterility in rice

Directory of Open Access Journals (Sweden)

Wang eKun

2013-04-01

Full Text Available 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 proteins related to cytoplasmic male sterility, photoperiod sensitive male sterility, self-incompatibility and other types of microspores deterioration have been characterized through genetics or proteomics. Especially the latter, offers us a powerful and high throughput approach to discern the novel proteins involving in male-sterile pathways which may help us to breed artificial male-sterile system. This represents an alternative tool to meet the critical challenge of further development of hybrid rice. In this paper, we reviewed the recent developments in our understanding of male sterility in rice hybrid production across gene, protein and integrated network levels, and also, present a perspective on the engineering of male sterile lines for hybrid rice production.

Genetically engineered Rice with transcription factor DREB genes for abiotic stress tolerance(abstract)

International Nuclear Information System (INIS)

Datta, S.K.; Datta, K.

2005-01-01

Water stress (drought and Salinity) is the most severe limitation to rice productivity. Several breeding approaches (MAS, QTL) applied to suitable genotypes are in place at IRRI and elsewhere. Phenotyping of water stress tolerance is in progress with potential predictability. Dr. Shinozaki's group has cloned a number of transcription factor genes, which have been shown to work in Arabidopsis to achieve drought, cold, and salinity tolerant plants. None of these genes have as yet displayed their potential functioning in rice. Genetic engineering aims at cross talk between different stress signaling pathways leading to stress tolerance. Osmotic Adjustment (OA) is an effective component of abiotic stress (drought and salinity) tolerance in many plants including rice. When plant experiences water stress, OA contributes to turgor maintenance of both shoots and roots. Conventional breeding could not achieve the OA in rice excepting a few rice cultivars, which are partially adapted to water-stress conditions. Several stress-related genes have now been cloned and transferred in to enhance the osmolytes and some transgenic lines showed increased tolerance to osmotic stress. A few strategies could be effectively deployed for a better understanding of water-stress tolerance in rice and to develop transgenic rice, which can survive for a critical period of water-stress conditions: 1) Switching on of transcription factor regulating the expression of several genes related to abiotic stress, 2) Use of a suitable stress inducible promoter driving the target gene for an efficient and directed expression in plants, 3) Understanding of phenotyping and GxE in a given environment, 4) Selection of a few adaptive rice cultivars suitable in drought/salinity prone areas, 5) Microarray, proteomics, QTL and MAS may expedite the cloning and characterizing the stress induced genes, and 6) Finally, the efficient transformation system for generating a large number of transgenic rice of different

Characterization of a disease susceptibility locus for exploring an efficient way to improve rice resistance against bacterial blight

Institute of Scientific and Technical Information of China (English)

Qi Cheng; Weihua Mao; Wenya Xie; Qinsong Liu; Jianbo Cao; Meng Yuan; Qinglu Zhang; Xianghua Li; Shiping Wang

2017-01-01

Bacterial blight caused by Xanthomonas oryzae pv.oryzae (Xoo) is the most harmful bacterial disease of rice worldwide.Previously,we characterized major disease resistance (MR) gene xa25,which confers race-specific resistance to Xoo strain PXO339.The xa25 is a recessive allele of the SWEET13 locus,but SWEET13's interaction with PXO339 and how efficiently using this locus for rice breeding still need to be defined.Here we show that the SWEET13 allele from rice Zhenshan 97 is a susceptibility gene to PXO339.Using this allele's promoter to regulate xa25 resulted in disease,suggesting that the promoter is a key determinant in SWEET13 caused disease in Zhanshan 97 after PXO339 infection.PXO339 transcriptionally induces SWEET13 to cause disease.Partial suppressing SWEET13 expression leads to a high level of resistance to PXO339.Thus,the transcriptionally suppressed SWEET13 functions as xa25 in resistance to PXO339.Hybrid rice is widely grown in many countries.However,recessive MR genes have not been efficiently used for disease resistance breeding in hybrid rice production for both parents of the hybrid have to carry the same recessive gene.However,the suppressed SWEET13 functions dominantly,which will have advantage to improve the resistance of hybrid rice to xa25-incomptible Xoo.

Effect of irradiation on physiological and biochemical properties of Bt rice seedlings

International Nuclear Information System (INIS)

Wang Zhonghua; Chen Xiaojian; Bao Xusheng; Chen Yuling; Gu Qinqin

2011-01-01

The seeds of two varieties of Bt rice were treated by 60 Co γ-rays at the doses of 50, 100, 150, 250 and 350 Gy, respectively, their original parent was used as control material. The seedlings cultured from above seeds were used to detect the root activity, seedling growth, chlorophyll content,activities of phenylalanine ammonialyase (PAL), polyphenol oxidase (PPO), catalase(CAT), superoxide dismutase (SOD) and amylase to investigate the effect of irradiation treatment on the physiological and biochemical properties of Bt rice. The results showed that root activity, chlorophyll content, activities of PAL, PPO, CAT, SOD of Bt rice seedlings and amylase of germinating seeds were lower than those of the control group after irradiation treatment of < 250 Gy, but the differences were not significant, which was similar to those of original parent. Meanwhile, it was found that with dose increasing, the seedling height was increased, suggesting that irradiation treatment could stimulate the seedling growth. Therefore, Bt transgene can not change the irradiation sensitivity of rice and the conventional method of rice can be used in Bt rice irradiation mutation breeding. (authors)

Introduction of a rice blight resistance gene, Xa21, into five Chinese rice varieties through an Agrobacterium-mediated system

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

A cloned gene, Xa21 was transferred into five widely-used Chinese rice varieties through an Agrobacterium-mediated system, and over 110 independent transgenic lines were obtained. PCR and Southern analysis of transgenic plants revealed the integration of the whole Xa21 gene into the host genomes. The integrated Xa21 gene was stably inherited, and segregated in a 3∶1 ratio in the selfed T1 generation when one copy of the gene was integrated in the transformants. Inoculation tests displayed that transgenic T0 plants and Xa21 PCR-positive T1 plants were highly resistant to bacterial blight disease. The selected Xa21 homozygous resistant transgenic lines with desirable qualities may be propagated as new varieties or utilized in hybrid rice breeding.

Introduction of a rice blight resistance gene, Xa21, into five Chinese rice varieties through an Agrobacterium -mediated system

Institute of Scientific and Technical Information of China (English)

翟文学; 李晓兵; 田文忠; 周永力; 潘学彪; 曹守云; 赵显峰; 赵彬; 章琦; 朱立煌

2000-01-01

A cloned gene, Xa21 was transferred into five widely-used Chinese rice varieties through an Agrobacterium-mediated system, and over 110 independent transgenic lines were obtained. PCR and Southern analysis of transgenic plants revealed the integration of the whole Xa21 gene into the host genomes. The integrated Xa21 gene was stably inherited, and segregated in a 3 : 1 ratio in the selfed T1 generation when one copy of the gene was integrated in the transfor-mants. Inoculation tests displayed that transgenic T0 plants and Xa21 PCR-positive T1 plants were highly resistant to bacterial blight disease. The selected Xa21 homozygous resistant transgenic lines with desirable qualities may be propagated as new varieties or utilized in hybrid rice breeding.

Mutation breeding for crop improvement: a review

International Nuclear Information System (INIS)

Awan, M.A.

1999-01-01

More than 70 years have passed since radiation was used successfully to generate genetic variation in plants. Since the research on theoretical basis of mutagenesis was performed with a peak in the mid sixties. The result of these investigations led to the formulation of methodological principles in the use of various mutagens for the creation and selection of desired variability. The induced genetic variability has been extensively used for evolution of crop varieties as well as in breeding programmes. More than 1800 varieties of 154 plants species have so far been released for commercial cultivation, of which cereals are at the top, demonstrating the economics of the mutation breeding technique. The most frequently occurring mutations have been the short stature and really maturity. In Pakistan, the use of mutation breeding technique for the improvement of crops has also led to the development of 34 cultivars of cotton, rice, wheat, chickpea, mungbean and rapeseed which have played a significant role in increasing crop production in the country. In addition, a wealth of genetic variability has been developed for use in the cross breeding programmes, and the breeders in Pakistan have released six varieties of cotton by using an induced mutant as one of the parents. (author)

Resistance of Rice Varieties to the Stored-Product Insect, Sitophilus zeamais (Coleoptera: Curculionidae).

Science.gov (United States)

Antunes, Catarina; Mendes, Raquel; Lima, Arlindo; Barros, Graça; Fields, Paul; Da Costa, Luísa Beirão; Rodrigues, José Carlos; Silva, Maria José; Correia, Augusto Manuel; Carvalho, Maria Otilia

2016-02-01

Four common Portuguese rice varieties--Thaibonnet, Gladio, Albatros, and Eurosis--were tested for their relative susceptibility to Sitophilus zeamais Motschulsky, a common pest of stored rice in Portugal and in tropical countries. Physical (moisture content, hardness, length, and width) and chemical (by attenuated total reflection-Fourier transform infrared spectroscopy) properties of rice kernels were measured. Insect bioassays measured median developmental time, Dobie's index of susceptibility, percentage of damaged grains and weight loss, and progeny developed. This was done for paddy, brown rice, and polished rice for each variety. There were small, but significant, differences in insect resistance among the varieties. However, it was different for paddy and polished rice. In paddy, these differences were correlated with hull damage, and Eurosis was the most susceptible variety. In polished rice, resistance was correlated with hardness, and Thaibonnet was the most susceptible variety. In general, paddy rice was more resistant to insect attack, followed by polished rice and then brown rice. Paddy kernels selected with undamaged hull were completely resistant to attack. Implications for IPM and breeding for resistant varieties are discussed. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Ornamental Plant Breeding

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Flávia Barbosa Silva Botelho

2015-04-01

Full Text Available World’s ornamental plant market, including domestic market of several countries and its exports, is currently evaluated in 107 billion dollars yearly. Such estimate highlights the importance of the sector in the economy of the countries, as well as its important social role, as it represents one of the main activities, which contributes to income and employment. Therefore a well-structured plant breeding program, which is connected with consumers’ demands, is required in order to fulfill these market needs globally. Activities related to pre-breeding, conventional breeding, and breeding by biotechnological techniques constitute the basis for the successful development of new ornamental plant cultivars. Techniques that involve tissue culture, protoplast fusion and genetic engineering greatly aid conventional breeding (germplasm introduction, plant selection and hybridization, aiming the obtention of superior genotypes. Therefore it makes evident, in the literature, the successful employment of genetic breeding, since it aims to develop plants with commercial value that are also competitive with the ones available in the market.

Positive-negative-selection-mediated gene targeting in rice

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Zenpei eShimatani

2015-01-01

Full Text Available Gene targeting (GT refers to the designed modification of genomic sequence(s through homologous recombination (HR. GT is a powerful tool both for the study of gene function and for molecular breeding. However, in transformation of higher plants, non-homologous end joining (NHEJ occurs overwhelmingly in somatic cells, masking HR-mediated GT. Positive-negative selection (PNS is an approach for finding HR-mediated GT events because it can eliminate NHEJ effectively by expression of a negative-selection marker gene. In rice—a major crop worldwide—reproducible PNS-mediated GT of endogenous genes has now been successfully achieved. The procedure is based on strong PNS using diphtheria toxin A-fragment as a negative marker, and has succeeded in the directed modification of several endogenous rice genes in various ways. In addition to gene knock-outs and knock-ins, a nucleotide substitution in a target gene was also achieved recently. This review presents a summary of the development of the rice PNS system, highlighting its advantages. Different types of gene modification and gene editing aimed at developing new plant breeding technology (NPBT based on PNS are discussed.

Diverse Rice Landraces of North-East India Enables the Identification of Novel Genetic Resources for Magnaporthe Resistance.

Science.gov (United States)

Umakanth, Bangale; Vishalakshi, Balija; Sathish Kumar, P; Rama Devi, S J S; Bhadana, Vijay Pal; Senguttuvel, P; Kumar, Sudhir; Sharma, Susheel Kumar; Sharma, Pawan Kumar; Prasad, M S; Madhav, Maganti S

2017-01-01

North-East (NE) India, the probable origin of rice has diverse genetic resources. Many rice landraces of NE India were not yet characterized for blast resistance. A set of 232 landraces of NE India, were screened for field resistance at two different hotspots of rice blast, viz., IIRR-UBN, Hyderabad and ICAR-NEH, Manipur in two consecutive seasons. The phenotypic evaluation as well as gene profiling for 12 major blast resistance genes ( Pitp , Pi33 , Pi54 , Pib , Pi20 , Pi38 , Pita2 , Pi1 , Piz , Pi9 , Pizt , and Pi40 ) with linked as well as gene-specific markers, identified 84 resistant landraces possessing different gene(s) either in singly or in combinations and also identified seven resistant landraces which do not have the tested genes, indicating the valuable genetic resources for blast resistance. To understand the molecular diversity existing in the population, distance and model based analysis were performed using 120 SSR markers. Results of both analyses are highly correlated by forming two distinct subgroups and the existence of high diversity (24.9% among the subgroups; 75.1% among individuals of each subgroup) was observed. To practically utilize the diversity in the breeding program, a robust core set having an efficiency index of 0.82 which consists of 33 landraces were identified through data of molecular, blast phenotyping, and important agro-morphological traits. The association of eight novel SSR markers for important agronomic traits which includes leaf and neck blast resistance was determined using genome-wide association analysis. The current study focuses on identifying novel resources having field resistance to blast as well as markers which can be explored in rice improvement programs. It also entails the development of a core set which can aid in representing the entire diversity for efficiently harnessing its properties to broaden the gene pool of rice.

Review. Promises, pitfalls and challenges of genomic selection in breeding programs

Energy Technology Data Exchange (ETDEWEB)

Ibanez-Escriche, N.; Gonzalez-Recio, O.

2011-07-01

The aim of this work was to review the main challenges and pitfalls of the implementation of genomic selection in the breeding programs of different livestock species. Genomic selection is now one of the main challenges in animal breeding and genetics. Its application could considerably increase the genetic gain in traits of interest. However, the success of its practical implementation depends on the selection scheme characteristics, and these must be studied for each particular case. In dairy cattle, especially in Holsteins, genomic selection is a reality. However, in other livestock species (beef cattle, small ruminants, monogastrics and fish) genomic selection has mainly been used experimentally. The main limitation for its implementation in the mentioned livestock species is the high geno typing costs compared to the low selection value of the candidate. Nevertheless, nowadays the possibility of using single-nucleotide polymorphism (SNP) chips of low density to make genomic selection applications economically feasible is under study. Economic studies may optimize the benefits of genomic selection (GS) to include new traits in the breeding goals. It is evident that genomic selection offers great potential; however, a suitable geno typing strategy and recording system for each case is needed in order to properly exploit it. (Author) 50 refs.

Fine mapping of the rice bacterial blight resistance gene Xa-4 and its co-segregation marker

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

An F2 population developed from the Xa-4 near isogenic lines,IR24 and IRBB4,was used for fine mapping of the rice bacterial blight resistance gene,Xa-4.Some restriction fragment length polymorphism (RFLP) markers on the high-density map constructed by Harushima et al.and the amplified DNA fragments homologous to the conserved domains of plant disease resistance (R) genes were used to construct the genetic linkage map around the gene Xa-4 by scoring susceptible individuals in the population.Xa-4 was mapped between the RFLP marker G181 and the polymerase chain reaction (PCR) marker M55.The R gene homologous fragment marker RS13 was found co-segregating with Xa-4 by analyzing all the plants in the population.This result opened an approach to map-based cloning of this gene,and marker RS13 can be applied to molecular marker-assisted selection of Xa-4 in rice breeding programs.

Study of space mutation breeding in China

International Nuclear Information System (INIS)

Wen Xianfang; Zhang Long; Dai Weixu; Li Chunhua

2004-01-01

This paper described the status of space mutation breeding in China. It emphasized that since 1978 Chinese space scientists and agricultural biologists have send 50 kg seeds of more than 70 crops including cereals, cotton, oil, vegetable, fruit and pasture to the space using the facilities such as return satellite 9 times, Shenzhou aircraft twice and high balloon 4 times. New varieties of 19 with high yield, high quality and disease-resistance, have been bred though years of breeding at the earth at more than 70 Chinese research institutes in 22 provinces. The new varieties include five rice varieties, two wheat varieties, two cotton varieties, one sweat pepper, one tomato variety, one sesame variety, three water melon varieties, three lotus varieties and one ganoderma lucidum variety. In addition more than 50 new lines and many other germplasm resources have been obtained. Study on space breeding mechanism, such as biological effect of space induction, genetic variation by cell and molecular techniques and simulated study at the earth, has been conducted, and some progresses have been achieved. Many space-breeding bases have been established in some provinces. Space varieties have been extended up to 270000 hectares, and some useful scientific achievements and social economic benefit had been made. The study of Chinese space mutation breeding is going ahead in the world. The paper also introduced the contribution and results made by return satellites of the first three generation in space science. Some basic parameters involved in the study on space mutation breeding of return satellites were listed

Tritium breeding blanket

International Nuclear Information System (INIS)

Smith, D.; Billone, M.; Gohar, Y.; Baker, C.; Mori, S.; Kuroda, T.; Maki, K.; Takatsu, H.; Yoshida, H.; Raffray, A.; Sviatoslavsky, I.; Simbolotti, G.; Shatalov, G.

1991-01-01

The terms of reference for ITER provide for incorporation of a tritium breeding blanket with a breeding ratio as close to unity as practical. A breeding blanket is required to assure an adequate supply of tritium to meet the program objectives. Based on specified design criteria, a ceramic breeder concept with water coolant and an austenitic steel structure has been selected as the first option and lithium-lead blanket concept has been chosen as an alternate option. The first wall, blanket, and shield are integrated into a single unit with separate cooling systems. The design makes extensive use of beryllium to enhance the tritium breeding ratio. The design goals with a tritium breeding ratio of 0.8--0.9 have been achieved and the R ampersand D requirements to qualify the design have been identified. 4 refs., 8 figs., 2 tabs

Development of aromatic giant-embryo rice by molecular marker-assisted selection

Directory of Open Access Journals (Sweden)

ZHU Yingdong

2013-12-01

Full Text Available Aromatic rice is loved for its distinctive aroma when cooking and eating.In this research,aromatic normal-embryo rice and non-aromatic giant-embryo rice,"Shangshida No.5",both bred by our laboratory,were selected as the parents for the hybridization.We used conventional breeding techniques as well as fragrance gene marker-assisted selection to derive new aromatic giant-embryo rice "Shangshida No.8".By comparing the agronomic and yield characters of "Shangshida No.5" and "Shangshida No.8",the average of filled grains per panicle of "Shangshida No.5" exceeds "Shangshida No.8" very significantly,while the average of effective panicles of "Shangshida No.8" is slightly more than "Shangshida No.5".Also,in the weight of thousand grains "Shangshida No.8" is slightly heavier than "Shangshida No.5".Thus,their grain weights per plant are close,29.10 g and 28.92 g respectively.By comparing the traits of rice embryo,there is no significant difference in embryo weight and volume.Also,there is no significant difference in weight ratio and volume ratio of embryo.This research has laid a solid foundation for further market development and application of aromatic giant-embryo rice.

Research and breeding for mechanical culture of rice in Surinam

NARCIS (Netherlands)

Have, ten H.

1967-01-01

Ten Have described the results of research on cultural practices and breeding work, on the very heavy clay soils of the Prince Bernhard Polder and the Wageningen Project during the years 1952 to 1965. The chapters are: Introduction, Surface and underground drainage, Tillage and seedbed preparation,

Rice antioxidants: phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, γ-oryzanol, and phytic acid

Science.gov (United States)

Goufo, Piebiep; Trindade, Henrique

2014-01-01

Epidemiological studies suggested that the low incidence of certain chronic diseases in rice-consuming regions of the world might be associated with the antioxidant compound contents of rice. The molecules with antioxidant activity contained in rice include phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, γ-oryzanol, and phytic acid. This review provides information on the contents of these compounds in rice using a food composition database built from compiling data from 316 papers. The database provides access to information that would have otherwise remained hidden in the literature. For example, among the four types of rice ranked by color, black rice varieties emerged as those exhibiting the highest antioxidant activities, followed by purple, red, and brown rice varieties. Furthermore, insoluble compounds appear to constitute the major fraction of phenolic acids and proanthocyanidins in rice, but not of flavonoids and anthocyanins. It is clear that to maximize the intake of antioxidant compounds, rice should be preferentially consumed in the form of bran or as whole grain. With respect to breeding, japonica rice varieties were found to be richer in antioxidant compounds compared with indica rice varieties. Overall, rice grain fractions appear to be rich sources of antioxidant compounds. However, on a whole grain basis and with the exception of γ-oryzanol and anthocyanins, the contents of antioxidants in other cereals appear to be higher than those in rice. PMID:24804068

Rice antioxidants: phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, γ-oryzanol, and phytic acid.

Science.gov (United States)

Goufo, Piebiep; Trindade, Henrique

2014-03-01

Epidemiological studies suggested that the low incidence of certain chronic diseases in rice-consuming regions of the world might be associated with the antioxidant compound contents of rice. The molecules with antioxidant activity contained in rice include phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, γ-oryzanol, and phytic acid. This review provides information on the contents of these compounds in rice using a food composition database built from compiling data from 316 papers. The database provides access to information that would have otherwise remained hidden in the literature. For example, among the four types of rice ranked by color, black rice varieties emerged as those exhibiting the highest antioxidant activities, followed by purple, red, and brown rice varieties. Furthermore, insoluble compounds appear to constitute the major fraction of phenolic acids and proanthocyanidins in rice, but not of flavonoids and anthocyanins. It is clear that to maximize the intake of antioxidant compounds, rice should be preferentially consumed in the form of bran or as whole grain. With respect to breeding, japonica rice varieties were found to be richer in antioxidant compounds compared with indica rice varieties. Overall, rice grain fractions appear to be rich sources of antioxidant compounds. However, on a whole grain basis and with the exception of γ-oryzanol and anthocyanins, the contents of antioxidants in other cereals appear to be higher than those in rice.

Use of CRISPR/Cas Genome Editing Technology for Targeted Mutagenesis in Rice.

Science.gov (United States)

Xu, Rongfang; Wei, Pengcheng; Yang, Jianbo

2017-01-01

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated protein (Cas) system is a newly emerging mutagenesis (gene-editing) tool in genetic engineering. Among the agriculturally important crops, several genes have been successfully mutated by the system, and some agronomic important traits have been rapidly generated, which indicates the potential applications in both scientific research and plant breeding. In this chapter, we describe a standard gene-editing procedure to effectively target rice genes and to make specific rice mutants using the CRISPR/Cas9 system mediated by Agrobacterium transformation.

A computational approach to animal breeding.

Science.gov (United States)

Berger-Wolf, Tanya Y; Moore, Cristopher; Saia, Jared

2007-02-07

We propose a computational model of mating strategies for controlled animal breeding programs. A mating strategy in a controlled breeding program is a heuristic with some optimization criteria as a goal. Thus, it is appropriate to use the computational tools available for analysis of optimization heuristics. In this paper, we propose the first discrete model of the controlled animal breeding problem and analyse heuristics for two possible objectives: (1) breeding for maximum diversity and (2) breeding a target individual. These two goals are representative of conservation biology and agricultural livestock management, respectively. We evaluate several mating strategies and provide upper and lower bounds for the expected number of matings. While the population parameters may vary and can change the actual number of matings for a particular strategy, the order of magnitude of the number of expected matings and the relative competitiveness of the mating heuristics remains the same. Thus, our simple discrete model of the animal breeding problem provides a novel viable and robust approach to designing and comparing breeding strategies in captive populations.

Induced Mutations in Thai Rice

International Nuclear Information System (INIS)

Klakhaeng, Kanchana

2014-01-01

Rice is the primary source of food for more than half of the world's population. It benefits greatly from technological inputs in the area of breeding such as induced mutation. Induced mutation can produce mutants with significant improvement in plant type, maturity, yields and protein ratio when compared to the parent. These improved traits enable the mutants to fit into farming systems with either shorter or longer growing seasons. Three induced mutant rice varieties, including RD6, RD10 and RD15, are well accepted by farmers and consumers in Thailand. RD6 and RD15 were aromatic, photosensitive varieties which were derived from KDML105 by acute irradiation of 20 and 15 kilorad gamma ray, respectively. After induced mutation, pedigree selection was applied. RD6 showed drought tolerance and also good grain quality including softness and good aroma with a higher average yield than the famous glutinous variety, San-Pah-Tong. Additionally, it was resistant to blast and brown spot diseases with an average yield of 4.19 tons/ha. RD15 showed drought tolerance and resistance to brown spot disease with the highest yield of 3.5 tons/ha. These two mutant varieties are currently the most famous aromatic rice varieties in Thailand. On the other hand, RD10 is a glutinous, photoperiod insensitive rice variety which was derived from RD1 by irradiation of 1 kilorad fast neutrons. RD10 showed good grain quality such as softness and stickiness with the yield of 4.25 tons/ha. As an on-going project, recommended rice varieties were irradiated with electron beam for anaerobic germination ability, submergence tolerance, stagnant-flood tolerance and also internode elongation.

The identification of specific cDNA clones from tall and dwarf rice plants

International Nuclear Information System (INIS)

Youssefian, S.; Kamada, I.; Sano, H.

1990-01-01

Full text: The use of dwarfing genes in rice breeding has proceeded for several years without a clear understanding of the genetic, hormonal and physiological mechanisms involved. This issue was addressed by focussing on the isolation of specific clones from tall- and dwarf-derived cDNA libraries. The materials used include near-isogenic lines of the tall rice cultivar 'Shiokari', differing at the DGWG or 'Tanginbozu' dwarfing gene loci. Also used were tall and dwarf 'Ginbozu' rice, the latter having been induced by treatment with 5-azacytidine, a potent demethylating agent. Subtractive and differential hybridisation have, to date, identified several candidate tall- and dwarf-specific clones. Their further characterisation is currently underway. (author)

Diversity and population structure of red rice germplasm in Bangladesh.

Directory of Open Access Journals (Sweden)

M Z Islam

breeding programs.

Functional Marker Assisted Improvement of Stable Cytoplasmic Male Sterile Lines of Rice for Bacterial Blight Resistance

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Jegadeesan Ramalingam

2017-06-01

Full Text Available Bacterial blight (BB, caused by Xanthomonas oryzae pv.oryzae is one among the major diseases in rice, which in severe condition cause losses up to 60% in total yield. Marker assisted pyramiding of three broad spectrum BB resistance genes (xa5, xa13, and Xa21 in prominent rice varieties is the most economical and effective strategy for the management of the BB disease. We report here the pyramiding of three genes (xa5, xa13, and Xa21 in maintainer lines (CO 2B, CO 23B, and CO 24B of three promising wild abortive cytoplasmic male sterile lines (CO 2A, CO 23A, and CO 24A through functional markers assisted back cross breeding. IRBB60 with xa5, xa13, and Xa21 genes is used as a donor parent. BC2F1 and BC2F2 generations from a cross of CO 2B, CO 23B, and CO 24B with IRBB60 were evaluated for bacterial blight and non-fertility restoration. In BC2F1, plants with all three resistance genes (xa5, xa13, and Xa21 and high parent genome recovery was identified. In BC2F2, plants with all resistance genes and without fertility restorer (Rf3 and Rf4 were selected. Based on agronomic traits, BB resistance and maintenance of sterility, two plants each in CO 2B × IRBB60, CO 24B × IRBB60 and one plant in CO 23B × IRBB60 combinations were identified. The identified lines were crossed with respective male sterile lines for conversion of improved B line into CMS line through back-crossing, in addition to selfing. The plants with high recurrent genome and phenotypically similar to parental lines and sterile are being used for the hybrid rice development program. Currently, using these lines (improved CMS line, test crosses were made to develop new rice hybrids. Hybrids combinations viz., CO 23A × AD08009R and CO 24A × IET20898R were found to be stable at different locations with high yield. The R line used in this study has been introgressed with xa5, xa13, and Xa21 genes in a separate breeding program. These new hybrids with resistance against bacterial blight

Mutation breeding newsletter. No. 45

International Nuclear Information System (INIS)

2001-07-01

This issue of the Mutation Breeding newsletter contains 39 articles dealing with radiation induced mutations and chemical mutagenesis techniques in plant breeding programs with the aims of improving crop productivity and disease resistance as well as exploring genetic variabilities

Characteristics important for organic breeding of vegetable crops

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Zdravković Jasmina

2010-01-01

Full Text Available The remarkable development and application of new genetic The Institute for Vegetable Crops possesses a rich germplasm collection of vegetables, utilized as gene resource for breeding specific traits. Onion and garlic breeding programs are based on chemical composition improvement. There are programs for identification and use of genotypes characterized by high tolerance to economically important diseases. Special attention is paid to breeding cucumber and tomato lines tolerant to late blight. As a result, late blight tolerant pickling cucumber line, as well as late blight tolerant tomato lines and hybrids are realized. Research on bean drought stress tolerance is initiated. Lettuce breeding program including research on spontaneous flora is started and interspecies hybrids were observed as possible genetic variability source. It is important to have access to a broad range of vegetable genotypes in order to meet the needs of organic agriculture production. Appreciating the concept of sustainable agriculture, it is important to introduce organic agriculture programs in breeding institutions.

Impact of SNPs on Protein Phosphorylation Status in Rice (Oryza sativa L.

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Shoukai Lin

2016-11-01

Full Text Available Single nucleotide polymorphisms (SNPs are widely used in functional genomics and genetics research work. The high-quality sequence of rice genome has provided a genome-wide SNP and proteome resource. However, the impact of SNPs on protein phosphorylation status in rice is not fully understood. In this paper, we firstly updated rice SNP resource based on the new rice genome Ver. 7.0, then systematically analyzed the potential impact of Non-synonymous SNPs (nsSNPs on the protein phosphorylation status. There were 3,897,312 SNPs in Ver. 7.0 rice genome, among which 9.9% was nsSNPs. Whilst, a total 2,508,261 phosphorylated sites were predicted in rice proteome. Interestingly, we observed that 150,197 (39.1% nsSNPs could influence protein phosphorylation status, among which 52.2% might induce changes of protein kinase (PK types for adjacent phosphorylation sites. We constructed a database, SNP_rice, to deposit the updated rice SNP resource and phosSNPs information. It was freely available to academic researchers at http://bioinformatics.fafu.edu.cn. As a case study, we detected five nsSNPs that potentially influenced heterotrimeric G proteins phosphorylation status in rice, indicating that genetic polymorphisms showed impact on the signal transduction by influencing the phosphorylation status of heterotrimeric G proteins. The results in this work could be a useful resource for future experimental identification and provide interesting information for better rice breeding.

Dietary safety assessment of genetically modified rice EH rich in β-carotene.

Science.gov (United States)

Wu, Yangyang; Xu, Yan; Du, Yanan; Zhao, Xiao; Hu, Ruili; Fan, Xiaorui; Ren, Fangfang; Yao, Quanhong; Peng, Rihe; Tang, Xueming; Zhao, Kai

2017-08-01

This 90-day study aimed to assess the dietary safety of transgenic rice EH which is rich in β-carotene. Two experimental groups of Sprague-Dawley rats were fed diets containing 45% rice flour of Zhonghua 11 rice and transgenic rice EH rich in β-carotene, respectively. The reference group was fed a diet containing standard feed nutrition. During the trial period, each rat was weighed and the food intake was recorded twice a week. Their behaviors were observed daily. In the end, blood samples were obtained from all anesthetized rats to measure the hematologic and serum chemistry indicators. Growth performance, anatomy and pathology of all organs in each group were analyzed. Although a few parameters were found to be statistically significantly different across groups, they were within the normal reference range for this breed and age of rats. Therefore, the changes were not considered to be diet related. The results revealed that the transgenic rice EH rich in β-carotene was as nutritious as Zhonghua 11 rice and showed a lack of biologically meaningful unintended effects. Copyright © 2017 Elsevier Inc. All rights reserved.

Genomic resources in mungbean for future breeding programs

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Sue K Kim

2015-08-01

Full Text Available Among the legume family, mungbean (Vigna radiata has become one of the important crops in Asia, showing a steady increase in global production. It provides a good source of protein and contains most notably folate and iron. Beyond the nutritional value of mungbean, certain features make it a well-suited model organism among legume plants because of its small genome size, short life-cycle, self-pollinating, and close genetic relationship to other legumes. In the past, there have been several efforts to develop molecular markers and linkage maps associated with agronomic traits for the genetic improvement of mungbean and, ultimately, breeding for cultivar development to increase the average yields of mungbean. The recent release of a reference genome of the cultivated mungbean (V. radiata var. radiata VC1973A and an additional de novo sequencing of a wild relative mungbean (V. radiata var. sublobata has provided a framework for mungbean genetic and genome research, that can further be used for genome-wide association and functional studies to identify genes related to specific agronomic traits. Moreover, the diverse gene pool of wild mungbean comprises valuable genetic resources of beneficial genes that may be helpful in widening the genetic diversity of cultivated mungbean. This review paper covers the research progress on molecular and genomics approaches and the current status of breeding programs that have developed to move toward the ultimate goal of mungbean improvement.

A walk on the wild side: Oryza species as source for rice abiotic stress tolerance.

Science.gov (United States)

Menguer, Paloma Koprovski; Sperotto, Raul Antonio; Ricachenevsky, Felipe Klein

2017-01-01

Oryza sativa, the common cultivated rice, is one of the most important crops for human consumption, but production is increasingly threatened by abiotic stresses. Although many efforts have resulted in breeding rice cultivars that are relatively tolerant to their local environments, climate changes and population increase are expected to soon call for new, fast generation of stress tolerant rice germplasm, and current within-species rice diversity might not be enough to overcome such needs. The Oryza genus contains other 23 wild species, with only Oryza glaberrima being also domesticated. Rice domestication was performed with a narrow genetic diversity, and the other Oryza species are a virtually untapped genetic resource for rice stress tolerance improvement. Here we review the origin of domesticated Oryza sativa from wild progenitors, the ecological and genomic diversity of the Oryza genus, and the stress tolerance variation observed for wild Oryza species, including the genetic basis underlying the tolerance mechanisms found. The summary provided here is important to indicate how we should move forward to unlock the full potential of these germplasms for rice improvement.

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.

The use of optical markers for mutation breeding

International Nuclear Information System (INIS)

Makino, Takahiro

2003-01-01

The use of radiation for mutation breeding has produced many kinds of practical varieties in crops and ornamental plants over the last several decades. Cold-tolerant rice and disease-resistant apple and pears are well-known varieties resulting from radiation breeding in Japan, and X-ray mutations were used routinely for the expansion of petal color in the chrysanthemum. Recently, the use of ion-beams for mutation induction was investigated as an effective source for producing varieties in cereal crops and flowers in Japan and China (Harten, 1998). Although we have not produced many varieties through radiation breeding, the success rate could increase with the addition of more resources. The success of mutation breeding greatly depends on the rate of mutation, the number of screened plants, and the mutation efficiency. The mutation rate is mainly a function of the total dose of the mutagen employed, although it can be modified by physical and biological factors. A large number of reports have been produced and effective methods of mutation treatments, such as gamma rays, established. Using higher doses inevitably brings about mortality, high pollen and seed sterility, and deleterious mutations. A practical useful dosage is usually found in the range much less than the maximum dose that can be applied. To increase the efficiency of mutation breeding, improvement of screening methods is more important than trials used for raising mutation probabilities. For this reason, we began studies to develop non-destructive and non-invasive optical high-throughput screening systems to increase the efficiency of mutation breeding. (author)

Evaluation of rice genotypes under salt stress at the seedling and reproductive stages using phenotypic and molecular markers

International Nuclear Information System (INIS)

Rubel, M.H.; Hassan, L.

2014-01-01

Salinity screening for 27 rice genotypes was performed at the seedling and reproductive stages respectively, in the hydroponic system and in sustained water bath. Three selected SSR markers were used to determine salinity tolerance in rice genotypes. Phenotyping of the germplasm was done at EC 12dS/m and 6dS/m at seedling and reproductive stages, respectively. Based on modified standard evaluation score for visual salt injury at seedling stage, eight genotypes were salt tolerant, four were moderately tolerant and the rest fifteen were susceptible. At the reproductive stage, six genotypes were tolerant to EC 6dS/m whereas eleven of them were susceptible. SSR based marker identified seven genotypes as tolerant but ten of them were susceptible for all three markers compared to two checks. Six genotypes were tolerant in both phenotypic and SSR screening. The indentified salt tolerant genotypes can be potential germplasm sources for future breeding program. (author)

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)

A major QTL controlling deep rooting on rice chromosome 4.

Science.gov (United States)

Uga, Yusaku; Yamamoto, Eiji; Kanno, Noriko; Kawai, Sawako; Mizubayashi, Tatsumi; Fukuoka, Shuichi

2013-10-24

Drought is the most serious abiotic stress that hinders rice production under rainfed conditions. Breeding for deep rooting is a promising strategy to improve the root system architecture in shallow-rooting rice cultivars to avoid drought stress. We analysed the quantitative trait loci (QTLs) for the ratio of deep rooting (RDR) in three F₂ mapping populations derived from crosses between each of three shallow-rooting varieties ('ARC5955', 'Pinulupot1', and 'Tupa729') and a deep-rooting variety, 'Kinandang Patong'. In total, we detected five RDR QTLs on chromosomes 2, 4, and 6. In all three populations, QTLs on chromosome 4 were found to be located at similar positions; they explained from 32.0% to 56.6% of the total RDR phenotypic variance. This suggests that one or more key genetic factors controlling the root growth angle in rice is located in this region of chromosome 4.

NOTE - Program R: applications in plant breeding

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Luiz Alexandre Peternelli

2011-01-01

Full Text Available Nowadays the demand for so-called free, or open source software for data analysis as well as the appeal to use it isgreat. An public domain software that has become extremely well-known, with ever-increasing numbers of fans and even coworkers, is Environment R, or simply R. R is extremely useful for data analysis and manipulation in view of a range of tools alreadyimplemented. Also, R is not simply a statistical program, because, by its easy on using internal functions and also creating new ones,statistical procedures applied to data can also be created, manipulated, evaluated and interpreted. R contains numerous libraries(or packages, some already included in the default setting. This course will focus on the application of R in statistical analyses inplant breeding. Explanations on the use of various commands and functions will be illustrated with examples, to facilitate theinterpretation and adaptation to other similar problems.

Genetically Modified Rice Adoption: Implications for Welfare and Poverty Alleviation

OpenAIRE

Anderson, Kym; Jackson, Lee Ann; Nielsen, Chantal Pohl

2004-01-01

The first generation of genetically modified (GM) crop varieties sought to increase producer profitability through cost reductions or higher yields, while the next generation of GM food research is focusing on breeding for attributes of interest to consumers. Golden Rice, for example, has been genetically engineered to contain a higher level of vitamin A and thereby boost the health of po...

Development of the variety for resistance against bacterial leaf-blight in rice with thermal neutrons

International Nuclear Information System (INIS)

Nakai, Hirokazu

1990-01-01

In search for the development of genes for resistance against bacterial leaf-blight in rice, thermal neutrons generated from the Research Reactor at the Kyoto University have been applied to the breeding. In this paper, the developmental outcome is described, and a potential application of thermal neutrons for breeding the variety of resistance against bacterial leaf-blight in rice is reviewed. When thermal neutrons were delivered to the rice, the ratio of absorbed doses by B-10, which is contained in a small quantity in the plant, was found to be larger than expected. This implies characteristic effects of thermal neutrons on the plant. When boric acid was incorporated into the plant before irradiation, the effect of thermal neutrons per irradiation time was considered to become great. The frequency of mutations for resistance was significantly higher by thermal neutron, as compared with that induced by other mutagens, such as gamma radiation, ethylene-imine, ethyl-methane-sulfonate, and nitroso-methyl-urea. Genetic analysis of mutants for resistance revealed recessive genes and polygenes. Finally, the application of thermal neutrons and other radiations would contribute greatly to a resolution of serious pollution problems in global food and environment. (N.K.)

Genetic improvement of Eucalyptus grandis using breeding seedling ...

African Journals Online (AJOL)

Eucalyptus grandis is commercially important in Zimbabwe and a breeding program has been in progress since 1962. A classical breeding strategy was used initially but, in 1981, the Multiple Population Breeding Strategy (MPBS) was implemented and the concept of the Breeding Seedling Orchard (BSO) became central to ...

Present status of rice breeding by induced mutations in Taiwan, Republic of China

Energy Technology Data Exchange (ETDEWEB)

Hu, C H [Taiwan Provincial Chung-Hsing University, Taichung, Taiwan (China); Wu, H P; Li, H W [Academia Sinica, Nankang, Taipei, Taiwan (China)

1970-03-01

Since 1957, fourteen varieties, including both indica and japonica, have been treated with X-rays, gamma rays, thermal neutrons and EMS for inducing mutations. The objectives are: (1) To obtain erectoid mutants of good lodging resistance from the tall native varieties which can be adapted for intensive culture; (2) To obtain early maturing mutants with at least the same yield as the original variety, so that the multiple cropping system of Taiwan can be easily handled; and (3) To obtain disease-resistant mutants. The results obtained suggest that after a useful gene such as erectoid has been obtained by induced mutation, it can be used immediately. But in general, it will be more useful to combine this character into other genotypic backgrounds by cross-breeding. Henceforth, further breeding must be carried out by cross-breeding. A number of promising lines were selected from induced mutants after being crossed with local varieties and the advanced test of these lines is being carried on at present. (author)

Present status of rice breeding by induced mutations in Taiwan, Republic of China

International Nuclear Information System (INIS)

Hu, C.H.; Wu, H.P.; Li, H.W.

1970-01-01

Since 1957, fourteen varieties, including both indica and japonica, have been treated with X-rays, gamma rays, thermal neutrons and EMS for inducing mutations. The objectives are: (1) To obtain erectoid mutants of good lodging resistance from the tall native varieties which can be adapted for intensive culture; (2) To obtain early maturing mutants with at least the same yield as the original variety, so that the multiple cropping system of Taiwan can be easily handled; and (3) To obtain disease-resistant mutants. The results obtained suggest that after a useful gene such as erectoid has been obtained by induced mutation, it can be used immediately. But in general, it will be more useful to combine this character into other genotypic backgrounds by cross-breeding. Henceforth, further breeding must be carried out by cross-breeding. A number of promising lines were selected from induced mutants after being crossed with local varieties and the advanced test of these lines is being carried on at present. (author)

Development of meat cattle breeding under respecialization programs in the Gomel area [Belarus

International Nuclear Information System (INIS)

Karpenko, A.F.; Mostovenko, A.L.; Radchikov, V.F.; Tsaj, V.P.

2011-01-01

In the conditions of the Republic of Belarus there was studied scientific management of introduction of 8 programmes of meat cattle breeding in regions of radioactive pollution in Gomel region. In course of the realized study there were analyzed land areas of the local farms, degree of soil contamination with radionuclides, coefficients of radionuclide transfer into plants and animal husbandry products, rate of production volumes, structure of arable lands and main herds, economic indexes of realized activities, etc. Introduction of programs of development of meat cattle breeding in the polluted areas made it possible to increase both the total and pedigree stock in the Gomel area, to create industrial base for reproduction of livestock and a wide circulation of specialized meat livestock in other farms of the polluted regions

Biodiversity Conservation in Rice Paddies in China: Toward Ecological Sustainability

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Yufeng Luo

2014-09-01

Full Text Available Rice paddies are artificial wetlands that supply people with food and provide wildlife with habitats, breeding areas, shelters, feeding grounds and other services, and rice paddies play an important part in agricultural ecological systems. However, modern agricultural practices with large-scale intensive farming have significantly accelerated the homogenization of the paddy field ecosystem. Modern agriculture mostly relies on chemically-driven modern varieties and irrigation to ensure high production, resulting in the deterioration and imbalance of the ecosystem. Consequently, outbreaks of diseases, insects and weeds have become more frequent in paddy fields. This paper describes the current situation of rice paddy biodiversity in China and analyzes the community characteristics of arthropods and weedy plants. Meanwhile, we discuss how biodiversity was affected by modern agriculture changes, which have brought about a mounting crisis threatening to animals and plants once common in rice paddies. Measures should be focused to firstly preventing further deterioration and, then, also, promoting restoration processes. Ecological sustainability can be achieved by restoring paddy field biodiversity through protecting the ecological environment surrounding the paddy fields, improving paddy cropping patterns, growing rice with less agricultural chemicals and chemical fertilizers, constructing paddy systems with animals and plants and promoting ecological education and public awareness.

Agriculture and the promotion of insect pests: rice cultivation in river floodplains and malaria vectors in The Gambia

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Louca Vasilis

2009-07-01

Full Text Available Abstract Background Anthropogenic modification of natural habitats can create conditions in which pest species associated with humans can thrive. In order to mitigate for these changes, it is necessary to determine which aspects of human management are associated with the promotion of those pests. Anopheles gambiae, the main Africa malaria vector, often breeds in rice fields. Here the impact of the ancient practice of 'swamp rice' cultivation, on the floodplains of the Gambia River, on the production of anopheline mosquitoes was investigated. Methods Routine surveys were carried out along 500 m transects crossing rice fields from the landward edge of the floodplains to the river during the 2006 rainy season. Aquatic invertebrates were sampled using area samplers and emergence traps and fish sampled using nets. Semi-field experiments were used to investigate whether nutrients used for swamp rice cultivation affected mosquito larval abundance. Results At the beginning of the rainy season rice is grown on the landward edge of the floodplain; the first area to flood with fresh water and one rich in cattle dung. Later, rice plants are transplanted close to the river, the last area to dry out on the floodplain. Nearly all larval and adult stages of malaria vectors were collected 0–100 m from the landward edge of the floodplains, where immature rice plants were grown. These paddies contained stagnant freshwater with high quantities of cattle faeces. Semi-field studies demonstrated that cattle faeces nearly doubled the number of anopheline larvae compared with untreated water. Conclusion Swamp rice cultivation creates ideal breeding sites for malaria vectors. However, only those close to the landward edge harboured vectors. These sites were productive since they were large areas of standing freshwater, rich in nutrients, protected from fish, and situated close to human habitation, where egg-laying mosquitoes from the villages had short distances to

Molecular mapping and genetic analysis of a rice brown planthopper (Nilaparvata lugens Stål) resistance gene.

Science.gov (United States)

Yang, Haiyuan; Ren, Xiang; Weng, Qingmei; Zhu, Lili; He, Guangcun

2002-01-01

The brown planthopper (BPH), Nilaparvata lugens Stål, is a serious insect pest of rice (Oryza saliva L.). We have determined the chromosomal location of a BPH resistance gene in rice using SSR and RFLP techniques. A rice line 'B14', derived from the wild rice Oryza latifolia, showed high resistance to BPH. For tagging the resistance gene in 'B14X', an F2 population and a recombinant inbred (RI) population from a cross between Taichung Native 1 and 'B14' were developed and evaluated for BPH resistance. The results showed that a single dominant gene controlled the resistance of 'B14' to BPH. Bulked segregant SSR analysis was employed for identification of DNA markers linked to the resistance gene. From the survey of 302 SSR primer pairs, three SSR (RM335, RM261, RM185) markers linked to the resistance gene were identified. The closest SSR marker RM261 was linked to the resistance gene at a distance of 1.8 cM. Regions surrounding the resistance gene and the SSR markers were examined with additional RFLP markers on chromosome 4 to define the location of the resistance gene. Linkage of RFLP markers C820, R288, C946 with the resistance gene further confirmed its location on the short arm of chromosome 4. Closely linked DNA markers will facilitate selection for resistant lines in breeding programs and provide the basis for map-based cloning of this resistance gene.

Geographic and research center origins of rice resistance to asian planthoppers and leafhoppers: implications for rice breeding and gene deployment

NARCIS (Netherlands)

Horgan, F.G.; Srinivasan, Thanga Suja; Bentur, Jagadish S.; Kumar, R.; Bhanu, K.V.; Singh Sarao, Preetinder; Chien, Ho Van; Almazan, M.L.P.; Bernal, Carmencita C.; Ramal, Angelee Fame; Ferrater, J.B.; Huang, Shou Horng

2017-01-01

This study examines aspects of virulence to resistant rice varieties among planthoppers and leafhoppers. Using a series of resistant varieties, brown planthopper, Nilaparvata lugens, virulence was assessed in seedlings and early-tillering plants at seven research centers in South and East Asia.

Resistance of rice to insect pests mediated by suppression of serotonin biosynthesis.

Science.gov (United States)

Lu, Hai-Ping; Luo, Ting; Fu, Hao-Wei; Wang, Long; Tan, Yuan-Yuan; Huang, Jian-Zhong; Wang, Qing; Ye, Gong-Yin; Gatehouse, Angharad M R; Lou, Yong-Gen; Shu, Qing-Yao

2018-05-07

Rice is one of the world's most important foods, but its production suffers from insect pests, causing losses of billions of dollars, and extensive use of environmentally damaging pesticides for their control 1,2 . However, the molecular mechanisms of insect resistance remain elusive. Although a few resistance genes for planthopper have been cloned, no rice germplasm is resistant to stem borers. Here, we report that biosynthesis of serotonin, a neurotransmitter in mammals 3 , is induced by insect infestation in rice, and its suppression confers resistance to planthoppers and stem borers, the two most destructive pests of rice 2 . Serotonin and salicylic acid derive from chorismate 4 . In rice, the cytochrome P450 gene CYP71A1 encodes tryptamine 5-hydroxylase, which catalyses conversion of tryptamine to serotonin 5 . In susceptible wild-type rice, planthopper feeding induces biosynthesis of serotonin and salicylic acid, whereas in mutants with an inactivated CYP71A1 gene, no serotonin is produced, salicylic acid levels are higher and plants are more insect resistant. The addition of serotonin to the resistant rice mutant and other brown planthopper-resistant genotypes results in a loss of insect resistance. Similarly, serotonin supplementation in artificial diet enhances the performance of both insects. These insights demonstrate that regulation of serotonin biosynthesis plays an important role in defence, and may prove valuable for breeding insect-resistant cultivars of rice and other cereal crops.

Identification of Rice Accessions Associated with K+/Na+ Ratio and Salt Tolerance Based on Physiological and Molecular Responses

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Inja Naga Bheema Lingeswara Reddy

2017-11-01

Full Text Available The key for rice plant survival under NaCl salt stress is maintaining a high K+/Na+ ratio in its cells. Selection for salt tolerance rice genotypes based on phenotypic performance alone will delay in progress in breeding. Use of molecular markers in tandem with physiological studies will help in better identification of salt tolerant rice accessions. Eight rice accessions along with the check Dongjin were screened using 1/2 Yoshida solution with 50 mmol/L NaCl at the seedling stage. The accessions IT001158, IT246674, IT260533 and IT291341 were classified as salt tolerant based on their K+/Na+ ratios. Seventeen SSR markers reported to be associated with K+/Na+ ratio were used to screen the accessions. Five SSR markers (RM8053, RM345, RM318, RM253 and RM7075 could differentiate accessions classified based on their K+/Na+ ratios. Banding pattern of the accessions was scored compared to the banding pattern of Dongjin. The study differentiated accessions based on their association of K+/Na+ ratio with molecular markers which are very reliable. These markers can play a significant role in screening large set of rice germplasms for salt tolerance and also help in identification of high-yielding varieties with better salt tolerance. The salt tolerant accessions can be taken forward into developing better varieties by conventional breeding and exploring genes for salt tolerance.

Effects of Position of Rainfed Rice Field in a Toposequence on Water Availability and Rice Yield in Central Java, Indonesia

OpenAIRE

SUGANDA, HUSEIN; PANINGBATAN, E.P; GUERRA, L.C; TUONG, T.P

2003-01-01

The productivity of rainfed rice needs to be increased in order to support the Indonesian Food Security programs, especially rice. Rainfall is one of the main sources of the water availability on the rainfed rice field. This research was conducted from October 2000 to February 2001 at four sites in Central Java Province. The objectives of this research were to study thevariability of water availability that influenced by toposequen's position and to analyze the rice yields due to treatments o...

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.

Assessment of genetic diversity among moderately drought tolerant landraces of rice using RAPD markers

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Md. Shariful Islam

2013-01-01

Full Text Available Genetic diversity and relationships among six rice genotypes were investigated using five random amplified polymorphic DNA (RAPD markers. A total of 69 alleles were amplified, of which 66 were polymorphic. The size of the amplified alleles was between 0.25 and 2.35 kbp. The number of polymorphic alleles detected with each primer ranged from 7 to 24 with an average of 13.2 per primer and the polymorphism information content (PIC values varied from 0.8672 to 0.9471. Pair-wise similarity estimated the range of 0.308 to 0.718 among all the genotypes and the highest genetic similarity was found between Maloti and BRRI dhan53. Cluster analysis using UPGMA (unweighted pair group method with arithmetic averages revealed three clusters at genetic similarity of 46%. A moderately drought tolerant landrace, Boalia, formed a single cluster and the remaining genotypes grouped into distinct clusters based on their relatedness. The results showed a high level of genetic diversity among studied genotypes and this information will assist in conservation as well as selection of parents during breeding programs for the development of drought tolerant rice varieties in near future.

Experimental alternatives for evaluation of progenies and clones in eucalyptus breeding programs

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Souza Elaine Aparecida de

2003-01-01

Full Text Available The feasibility of using augmented block designs and spatial analysis methods for early stage selection in eucalyptus breeding programs was tested. A total of 113 half-sib progenies of Eucalyptus urophylla and eight clones were evaluated in an 11 x 11 triple lattice experiment at two locations: Posto da Mata (Bahia, Brazil and São Mateus (Minas Gerais, Brazil. Four checks were randomly allocated within each block. Plots consisted of 15 m long rows containing 6 plants spaced 3 m apart. The girth at breast height (cm/plant was evaluated at 19 and 26 months of age. Variance analyses were performed according to the following methods: lattice design, randomized complete block design, augmented block design, Papadakis method, moving means method, and check plots. Comparisons among different methods were based on the magnitude of experimental errors and precision of the estimates of genetic and phenotypic parameters. General results indicated that augmented block design is useful to evaluate progenies and clones in early selection in eucalyptus breeding programs using moderate and low selection intensities. However, this design is not suitable for estimating genetic and phenotypic parameters due to its low precision. Check plots, nearest neighbour, Papadakis (1937, and moving means methods were efficient in removing the heterogeneity within blocks. These efficiencies were compared to that in lattice analysis for estimation of genetic and phenotypic parameters.

Tailoring Grain Storage Reserves for a Healthier Rice Diet and its Comparative Status with Other Cereals.

Science.gov (United States)

Butardo, Vito M; Sreenivasulu, Nese

2016-01-01

A global rise of diet-related noncommunicable diseases calls for a focus on diet-based nutritional intervention across the entire socioeconomic consumer spectrum. We review recent reports in the area of healthier rice aimed at developing rice grains with improved dietary fiber compositions (increased amounts of nonstarch polysaccharides and resistant starch), and less digestible starch (higher amylose and phospholipid complex in the endosperm) resulting in reduced glycemic impact upon grain consumption. We furthermore elaborate on the interconnections of elevated amounts of protein and a balanced composition of essential amino acids. The importance of a nutritious aleurone layer and its role in lipid storage and micronutrient composition is discussed briefly in the context of brown rice benefits. We identify gene targets for precision breeding that will facilitate the production of rice grains and rice-based products to mitigate the impact of nutrition-related preventable diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

Breeding quinoa (Chenopodium quinoa Willd.)

DEFF Research Database (Denmark)

Zurita-Silva, Andrés; Fuentes, Francisco; Zamora, Pablo

2014-01-01

scale. In the Andes, quinoa has until recently been marginally grown by small-scale Andean farmers, leading to minor interest in the crop from urban consumers and the industry. Quinoa breeding programs were not initiated until the 1960s in the Andes, and elsewhere from the 1970s onwards. New molecular...... tools available for the existing quinoa breeding programs, which are critically examined in this review, will enable us to tackle the limitations of allotetraploidy and genetic specificities. The recent progress, together with the declaration of "The International Year of the Quinoa" by the Food...

Formulating Phenological Equations for Rainfed Upland Rice in Bastar Plateau and Assessment of Genotype X Environment Interaction

International Nuclear Information System (INIS)

Kumar, P.; Sao, A.; Salam, J. L.; Kanwar, R. R.; Kumari, P.

2016-01-01

Upland rice encompasses 12 percent of global rice production area in the lowest yielding ecosystem, produced by poorest farmers with 0.5 ha average operational holdings. Due to subtle selection over long period of time, upland rice has become drought tolerant potential crop and harbors great genetic potential for future water limited rice. It has also precious traits like high pestilent insect resistant possibility and short growing season. In present investigation, 18 new genotypes were tested for upland ecology during Kharif 2013 and 2014, to identify promising genotypes and formulate phenological relationships at phenotypic and genotypic levels and estimate G x E interactions with uncertain weather parameters. The test populations exhibited enough variation to carry on crop breeding research however, genotypes responded differentially to water stress and late season drought with respect to morphological and yield traits. Considering secondary productivity factors (SPF), days to flowering, plant height, panicles per unit area, spikelet fertility and harvest index was observed to be major contributors for water scarce survivals. Biased selection for earliness cause reduction in grain yield due to shortened vegetative phase hence, research is to be focused to minimize the yield penalty associated with earliness. Among the genotypes evaluated, IR-83381-B-B-137-3 and IR-86857-46-1-1-2 was found to be promising for rainfed breeding programme as parent material. Based on results of farmer field and station trials, existing upland rice variety CR 40 is concluded as promising for upland ecology and will be crucial to uplift the economy of poor and marginal farmers of Chhattisgarh. (author)

Molecular diversity of Rice grassy stunt virus in Vietnam.

Science.gov (United States)

Ta, Hoang-Anh; Nguyen, Doan-Phuong; Causse, Sandrine; Nguyen, Thanh-Duc; Ngo, Vinh-Vien; Hébrard, Eugénie

2013-04-01

Rice grassy stunt virus (RGSV, Tenuivirus) recently emerged on rice in Vietnam, causing high yield losses during 2006-2009. The genetic diversity of RGSV is poorly documented. In this study, the two genes encoded by each ambisense segment RNA3 and RNA5 of RGSV isolates from six provinces of South Vietnam were sequenced. P3 and Pc3 (RNA3) have unknown function, P5 (RNA5) encodes the putative silencing suppressor, and Pc5 (RNA5) encodes the nucleocapsid protein (N). The sequences of 17 Vietnamese isolates were compared with reference isolates from North and South Philippines. The average nucleotide diversity among the isolates was low. We confirmed a higher variability of RNA3 than RNA5 and Pc3 than P3. No relationships between the genetic diversity and the geographic distribution of RGSV isolates could be ascertained, likely because of the long-distance migration of the insect vector. This data will contribute to a better understanding on the RGSV epidemiology in South Vietnam, a prerequisite for further management of the disease and rice breeding for resistance.

Rice mutants obtained through sodium azide (NaN3) treatment

International Nuclear Information System (INIS)

Silva, E.F.; Ando, A.; Tulmann Neto, A.

2001-01-01

The successful utilization of sodium azide to generate genetic variability in plant breeding has been reported in barley, rice, and other crops. Rice seeds of 'Dourado Precoce', Brazilian upland cultivar, were treated with 5x10 -3 M of sodium azide, prepared in buffer solution of pH 3,0, for 8 hours at laboratory temperature. Ten short culm mutant lines were selected in the M 2 , M 3 and M 4 generations. In the M 5 generation, the mutant lines were evaluated for flowering and maturing cycles, tiller number per plant, plant height, panicle number per m 2 , panicle length, fertility of panicle, weight of 1.000 grains, productivity, percentage of intact grains after milling, width and thickness of peeled and polished grains and length/width grain ratio. The experiment was conducted in the Centro Experimental of Instituto Agronomico, Campinas, Sao Paulo, Brazil, during the period of 1993/94, utilizing randomized block design with four replications. Each experimental plot consisted of five rows of four meters in length, 50 cm between rows, with 75 seeds sown per meter. The cultivar 'IAC 201' and the original Dourado Precoce were planted as checks. All observations were made on the three central rows of each experimental plot. The data was analysed by the SANEST statistical program and the mean values were discriminated by the Tukey's test at the level 5% of probability

Breeding and Selection of New Switchgrass Varieties for Increased Biomass Production

Energy Technology Data Exchange (ETDEWEB)

Taliaferro, C.M.

2003-05-27

Switchgrass breeding and genetics research was conducted from 1992-2002 at the Oklahoma State University as part of the national DOE-Bioenergy Feedstock Development Program (BFDP) effort to develop the species as a bioenergy feedstock crop. The fundamental objective of the program was to implement and conduct a breeding program to increase biomass yield capability in switchgrass and develop cultivars for the central and southern United States. Supporting research objectives included: (1) switchgrass germplasm collection, characterization, and enhancement; (2) elucidation of cytogenetic and breeding behavior; and (3) identification of best breeding procedures.

Phloem-exudate proteome analysis of response to insect brown plant-hopper in rice.

Science.gov (United States)

Du, Ba; Wei, Zhe; Wang, Zhanqi; Wang, Xiaoxiao; Peng, Xinxin; Du, Bo; Chen, Rongzhi; Zhu, Lili; He, Guangcun

2015-07-01

Brown plant-hopper (Nilaparvata lugens Stål, BPH), one of the most devastating agricultural insect pests of rice throughout Asia, ingests nutrients from rice sieve tubes and causes a dramatic yield loss. Planting resistant variety is an efficient and economical way to control this pest. Understanding the mechanisms of host resistance is extremely valuable for molecular design of resistant rice variety. Here, we used an iTRAQ-based quantitative proteomics approach to perform analysis of protein expression profiles in the phloem exudates of BPH-resistant and susceptible rice plants following BPH infestation. A total of 238 proteins were identified, most of which were previously described to be present in the phloem of rice and other plants. The expression of genes for selected proteins was confirmed using a laser capture micro-dissection method and RT-PCR. The mRNAs for three proteins, RGAP, TCTP, and TRXH, were further analyzed by using in situ mRNA hybridization and localized in the phloem cells. Our results showed that BPH feeding induced significant changes in the abundance of proteins in phloem sap of rice involved in multiple pathways, including defense signal transduction, redox regulation, and carbohydrate and protein metabolism, as well as cell structural proteins. The results presented provide new insights into rice resistance mechanisms and should facilitate the breeding of novel elite BPH-resistant rice varieties. Copyright © 2015 Elsevier GmbH. All rights reserved.

Marker-assisted backcrossing: a useful method for rice improvement.

Science.gov (United States)

Hasan, Muhammad Mahmudul; Rafii, Mohd Y; Ismail, Mohd R; Mahmood, Maziah; Rahim, Harun A; Alam, Md Amirul; Ashkani, Sadegh; Malek, Md Abdul; Latif, Mohammad Abdul

2015-03-04

The world's population is increasing very rapidly, reducing the cultivable land of rice, decreasing table water, emerging new diseases and pests, and the climate changes are major issues that must be addressed to researchers to develop sustainable crop varieties with resistance to biotic and abiotic stresses. However, recent scientific discoveries and advances particularly in genetics, genomics and crop physiology have opened up new opportunities to reduce the impact of these stresses which would have been difficult if not impossible as recently as the turn of the century. Marker assisted backcrossing (MABC) is one of the most promising approaches is the use of molecular markers to identify and select genes controlling resistance to those factors. Regarding this, MABC can contribute to develop resistant or high-yielding or quality rice varieties by incorporating a gene of interest into an elite variety which is already well adapted by the farmers. MABC is newly developed efficient tool by which using large population sizes (400 or more plants) for the backcross F 1 generations, it is possible to recover the recurrent parent genotype using only two or three backcrosses. So far, many high yielding, biotic and abiotic stresses tolerance, quality and fragrance rice varieties have been developed in rice growing countries through MABC within the shortest timeframe. Nowadays, MABC is being used widely in plant breeding programmes to develop new variety/lines especially in rice. This paper reviews recent literature on some examples of variety/ line development using MABC strategy.

Genetic control of plasticity in root morphology and anatomy of rice in response to water deficit

NARCIS (Netherlands)

Kadam, Niteen N.; Tamilselvan, Anandhan; Lawas, Lovely M.F.; Quinones, Cherryl; Bahuguna, Rajeev N.; Thomson, Michael J.; Dingkuhn, Michael; Muthurajan, Raveendran; Struik, Paul C.; Yin, Xinyou; Jagadish, Krishna S.V.

2017-01-01

Elucidating the genetic control of rooting behavior under water-deficit stress is essential to breed climate-robust rice (Oryza sativa) cultivars. Using a diverse panel of 274 indica genotypes grown under control and water-deficit conditions during vegetative growth, we phenotyped 35 traits, mostly

Revisiting GMOs: Are There Differences in European Consumers' Acceptance and Valuation for Cisgenically vs Transgenically Bred Rice?

Science.gov (United States)

Delwaide, Anne-Cécile; Nalley, Lawton L; Dixon, Bruce L; Danforth, Diana M; Nayga, Rodolfo M; Van Loo, Ellen J; Verbeke, Wim

2015-01-01

Both cisgenesis and transgenesis are plant breeding techniques that can be used to introduce new genes into plant genomes. However, transgenesis uses gene(s) from a non-plant organism or from a donor plant that is sexually incompatible with the recipient plant while cisgenesis involves the introduction of gene(s) from a crossable--sexually compatible--plant. Traditional breeding techniques could possibly achieve the same results as those from cisgenesis, but would require a much larger timeframe. Cisgenesis allows plant breeders to enhance an existing cultivar more quickly and with little to no genetic drag. The current regulation in the European Union (EU) on genetically modified organisms (GMOs) treats cisgenic plants the same as transgenic plants and both are mandatorily labeled as GMOs. This study estimates European consumers' willingness-to-pay (WTP) for rice labeled as GM, cisgenic, with environmental benefits (which cisgenesis could provide), or any combination of these three attributes. Data were collected from 3,002 participants through an online survey administered in Belgium, France, the Netherlands, Spain and the United Kingdom in 2013. Censored regression models were used to model consumers' WTP in each country. Model estimates highlight significant differences in WTP across countries. In all five countries, consumers are willing-to-pay a premium to avoid purchasing rice labeled as GM. In all countries except Spain, consumers have a significantly higher WTP to avoid consuming rice labeled as GM compared to rice labeled as cisgenic, suggesting that inserting genes from the plant's own gene pool is more acceptable to consumers. Additionally, French consumers are willing-to-pay a premium for rice labeled as having environmental benefits compared to conventional rice. These findings suggest that not all GMOs are the same in consumers' eyes and thus, from a consumer preference perspective, the differences between transgenic and cisgenic products are

The types and genetic analysis of radiation induced early maturity mutants of rice

International Nuclear Information System (INIS)

Yang Hefeng; Chen Xiulan; He Zhengtian; Gu Shiliang; Xu Chenwu

1989-01-01

Observation and correlation analysis were made for 50 early mutant lines,The early mutant lines fall into late type of early-maturity rice, and early type of mid- maturity rice, some of which are valuable as materials of rice breeding.With shorter growing period, the mutants have less inter-nodes and leaf numbers on main culm, shorter leaf and panicle length, and less filled grains and yield per plant, but have higher Protein content.Among 20 traits observed, 7 were significantly correlated with the length of growing period.The genetic parameter analysis for the mutant lines indicates that the length of growing period, plant height, grain number per panicle, 1000-grain weight have high heritability, Non-filled grain rate, secondary branch, number of panicle, grain number per panicle have larger genetic coefficient of variation and larger gain of selection

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

Directory of Open Access Journals (Sweden)

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.

Review of the cost components of introducing industrially fortified rice.

Science.gov (United States)

Roks, Eveline

2014-09-01

Micronutrient deficiencies affect over two billion people worldwide, particularly in developing countries. Fortification of staple foods with multiple micronutrients is a cost-effective strategy to increase vitamin and mineral intake. The objective of this paper is to review the cost elements of industrially fortified rice by identifying the costs related to the implementation of rice fortification programs, using the experience of the United Nations World Food Programme in its pilot countries. The actual total costs of rice fortification are not easily captured. Core cost elements include the production of fortified rice kernels, transportation to the point of blending, blending of fortified with unfortified rice, costs related to sales or distribution, quality control and assurance, and additional planning. In the introduction phase, organizations or coalitions seeking to advance rice fortification will face additional costs related to the initiation of rice fortification. In the scale-up phase, greater efficiency in the supply chain and economies of scale can be expected. Different cost elements are normally borne by different stakeholders. This makes the implementation of rice fortification programs a feasible option to reach vulnerable populations with inadequate access to affordable nutrition solutions. © 2014 New York Academy of Sciences.

CASSAVA BREEDING I: THE VALUE OF BREEDING VALUE

Directory of Open Access Journals (Sweden)

Hernán Ceballos

2016-08-01

Full Text Available Breeding cassava relies on several selection stages (single row trial-SRT; preliminary; advanced; and uniform yield trials - UYT. This study uses data from 14 years of evaluations. From more than 20,000 genotypes initially evaluated only 114 reached the last stage. The objective was to assess how the data at SRT could be used to predict the probabilities of genotypes reaching the UYT. Phenotypic data from each genotype at SRT was integrated into the selection index (SIN used by the cassava breeding program. Average SIN from all the progenies derived from each progenitor was then obtained. Average SIN is an approximation of the breeding value of each progenitor. Data clearly suggested that some genotypes were better progenitors than others (e.g. high number of their progenies reaching the UYT, suggesting important variation in breeding values of progenitors. However, regression of average SIN of each parental genotype on the number of their respective progenies reaching UYT resulted in a negligible coefficient of determination (r2 = 0.05. Breeding value (e.g. average SIN at SRT was not efficient predicting which genotypes were more likely to reach the UYT stage. Number of families and progenies derived from a given progenitor were more efficient predicting the probabilities of the progeny from a given parent reaching the UYT stage. Large within-family genetic variation tends to mask the true breeding value of each progenitor. The use of partially inbred progenitors (e.g. S1 or S2 genotypes would reduce the within-family genetic variation thus making the assessment of breeding value more accurate. Moreover, partial inbreeding of progenitors can improve the breeding value of the original (S0 parental material and sharply accelerate genetic gains. For instance, homozygous S1 genotypes for the dominant resistance to cassava mosaic disease could be generated and selected. All gametes from these selected S1 genotypes would carry the desirable allele

Development and evaluation of near-isogenic lines for brown planthopper resistance in rice cv. 9311

OpenAIRE

Cong Xiao; Jie Hu; Yi-Ting Ao; Ming-Xing Cheng; Guan-Jun Gao; Qing-Lu Zhang; Guang-Cun He; Yu-Qing He

2016-01-01

Brown planthopper (BPH) is the most destructive pest of rice in Asia. To date 29 BPH resistance genes have been identified, but only a few genes are being used in breeding due to inefficient markers for marker-assisted selection (MAS) and little knowledge of the real effects of the genes. In this study we individually transferred 13 genes or QTLs (Bph14, QBph3, QBph4, Bph17, Bph15, Bph20, Bph24, Bph6, Bph3, Bph9, Bph10, Bph18 and Bph21) into cultivar 9311 by marker assisted backcross breeding...

Achievements in the past twenty years and perspective outlook of crop space breeding in China

International Nuclear Information System (INIS)

Liu Luxiang; Guo Huijun; Zhao Linshu; Gu Jiayu; Zhao Shirong

2007-01-01

Space breeding is a novel effective approach to crop mutational improvement, which was firstly founded by the chinese scientists in 1987. A national collaborative research network has been established and significant achievements have been made during the past twenty years. More than forty new mutant varieties derived from space mutagenesis in rice, wheat, cotton, sweet pepper, tomato, sesame and alfalfa have been developed, officially released and put into production. A series of useful rare mutant germplasms which might make a great breakthrough in crop grain yield and/or quality improvement have been obtained. Technique innovations in space breeding and ground simulation of space environmental factors have been made good progresses. Intellective property right protection and industrialization of space mutation techniques and mutant varieties, exploration of the mechanism of space mutation induction have also been stably advanced. In this paper, the main achievements of crop space breeding in the past twenty years had been reviewed. The perspective development strategies of space breeding were also discussed. (authors)

Production objectives, trait and breed preferences of farmers keeping N'Dama, Fulani Zebu and crossbred cattle and implications for breeding programs.

Science.gov (United States)

Traoré, S A; Markemann, A; Reiber, C; Piepho, H P; Valle Zárate, A

2017-04-01

Many local livestock breeds in developing countries are being replaced by exotic breeds, leading to a loss of genetic resources. In southern Mali, for the past two decades, a trend towards increasing crossbreeding between the trypanotolerant N'Dama cattle and the trypano-susceptible Fulani Zebu cattle has been taking place. A survey with 160 farmers owning a cattle herd was carried out in southern Mali to investigate their production objectives, as well as trait and breed preferences and correlated socio-economic determinants in order to understand farmers' breeding decisions and to identify comparative advantages of three breed groups (N'Dama, Fulani Zebu and crossbreds) raised in the study area. Data were analyzed using an exploded logit model. The reasons for raising cattle, as well as trait and breed preferences reflected the multiple objectives of the farmers. Draught power and savings were the most important production objectives. Productive traits were ranked highest; farmers reported large body size as the most preferred trait, followed by fertility, draught ability and milk yield. Crossbreds were the favored breed group. Breed preferences were mainly explained by 'resistance to disease' for N'Dama cattle and 'high market price' for Fulani Zebu and crossbred cattle. Production objectives, trait and breed preferences were mainly influenced by farmer group (local farmers and settled transhumants). Local farmers put comparatively more emphasis on livestock functions linked to crop production such as draught power. They had a higher preference for traction ability as a selection trait and preferred N'Dama over Fulani Zebu cattle. Settled transhumants emphasized milk yield as a selection trait and preferred Fulani Zebu over N'Dama. The results indicate that the trend towards more crossbreeding will continue putting the N'Dama breed under high risk of genetic dilution in southern Mali. The N'Dama cattle remain a valuable breed due to their adaptive traits such as

Applying SNP marker technology in the cacao breeding program at the Cocoa Research Institute of Ghana

Science.gov (United States)

In this investigation 45 parental cacao plants and five progeny derived from the parental stock studied were genotyped using six SNP markers to determine off-types or mislabeled clones and to authenticate crosses made in the Cocoa Research Institute of Ghana (CRIG) breeding program. Investigation wa...

Genetic analysis of NPT II x HBC 19 (basmati variety) RIL's and ...

African Journals Online (AJOL)

HAU Vikram

attention due to greater preference in domestic and international markets. According to its grain shape, rice is ... Grain shape has attracted significant attention in rice breeding programs due to its contributions to rice ... smelling or chewing seeds is subjective and non-reliable as analyst sense become saturated or physical ...

Transfer of gaseous iodine from atmosphere to rough rice, brown rice and polished rice

International Nuclear Information System (INIS)

Sumiya, Misako; Uchida, Shigeo; Muramatsu, Yasuyuki; Ohmomo, Yoichiro; Yamaguchi, Shuho; Obata, Hitoshi.

1987-01-01

Experiments were carried out in order to obtain information required for establishing transfer coefficients of gaseous iodine (I 2 ) to rough rice, brown rice and polished rice. The gaseous iodine deposited on young rice plants before the heading period was scarcely found in the rough rice harvested at the full ripe stage. The biological half life of iodine in hull, however, was much slower than that in leaves of 14 days. The translocation of iodine from leaves and stalks to rough rice was not clearly recognized. Therefore, it was deduced that iodine found in brown rice mainly should originate from that deposited on the hull. The distribution ratios of iodine between rough rice and brown rice, and between brown rice and polished rice were 100:4 and 100:30 on 100 grains basis, respectively. If average normalized deposition velocity (V d(m) ) or derived deposition velocity (V s ) are given, the transfer coefficients of gaseous iodine to rough rice (TF r ), brown rice (TF b ) and polished rice (TF p ) could be calculated. (author)

Screening for Sugarcane Brown Rust in the First Clonal Stage of the Canal Point Sugarcane Breeding Program

Directory of Open Access Journals (Sweden)

Duli Zhao

2015-07-01

Full Text Available Sugarcane (Saccharum spp. brown rust (caused by Puccinia melanocephala Syd. & P. Syd. was first reported in the United States in 1978 and is still one of the great challenges for sugarcane production. A better understanding of sugarcane genotypic variation in response to brown rust will help optimize breeding and selection strategies for disease resistance. Brown rust ratings were scaled from non-infection (0 to severe infection (4 with intervals of 0.5 and routinely recorded for genotypes in the first clonal selection stage of the Canal Point sugarcane breeding program in Florida. Data were collected from 14,272 and 12,661 genotypes and replicated check cultivars in 2012 and 2013, respectively. Mean rust rating, % infection, and severity in each family and progeny of female parent were determined, and their coefficients of variation (CV within and among families (females were estimated. Considerable variation exists in rust ratings among families or females. The families and female parents with high susceptibility or resistance to brown rust were identified and ranked. The findings of this study can help scientists to evaluate sugarcane crosses and parents for brown rust disease, to use desirable parents for crossing, and to improve genetic resistance to brown rust in breeding programs.

A Rice Immunophilin Gene, OsFKBP16-3, Confers Tolerance to Environmental Stress in Arabidopsis and Rice

Directory of Open Access Journals (Sweden)

Jun Cheul Ahn

2013-03-01

Full Text Available The putative thylakoid lumen immunophilin, FKBP16-3, has not yet been characterized, although this protein is known to be regulated by thioredoxin and possesses a well-conserved CxxxC motif in photosynthetic organisms. Here, we characterized rice OsFKBP16-3 and examined the role of this gene in the regulation of abiotic stress in plants. FKBP16-3s are well conserved in eukaryotic photosynthetic organisms, including the presence of a unique disulfide-forming CxxxC motif in their N-terminal regions. OsFKBP16-3 was mainly expressed in rice leaf tissues and was upregulated by various abiotic stresses, including salt, drought, high light, hydrogen peroxide, heat and methyl viologen. The chloroplast localization of OsFKBP16-3-GFP was confirmed through the transient expression of OsFKBP16-3 in Nicotiana benthamiana leaves. Transgenic Arabidopsis and transgenic rice plants that constitutively expressed OsFKBP16-3 exhibited increased tolerance to salinity, drought and oxidative stresses, but showed no change in growth or phenotype, compared with vector control plants, when grown under non-stressed conditions. This is the first report to demonstrate the potential role of FKBP16-3 in the environmental stress response, which may be regulated by a redox relay process in the thylakoid lumen, suggesting that artificial regulation of FKBP16-3 expression is a candidate for stress-tolerant crop breeding.

Genetic and environmental variation in a commercial breeding program of perennial ryegrass

DEFF Research Database (Denmark)

Fé, Dario; Pedersen, Morten Greve; Jensen, Christian S

2015-01-01

on forage yield (green and dry matter) and six traits scored by visual inspection (i.e., rust resistance, aftermath heading, spring growth, density, winter hardiness, and heading date). Data were analyzed with linear mixed models, including fixed effects (trial and control varieties, within year...... for future GSbased breeding programs. Forage yield showed family heritabilities of up to 0.30 across locations and up to 0.60 within a location. Similar or moderately lower values were found for the other traits. In particular, the heritabilities of rust resistance and aftermath heading were very promising...

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.

Genetic improvement of rice (oryza sativa l.) by induced mutations

International Nuclear Information System (INIS)

Suarez, E.; Deus, J. E.; Perez, R.; Alfonso, R.; Hernandez, R.; Avila, J.; Hernandez, J. L.; Puldon, Violeta; Duany, A.; Reinoso, J.; Mesa, H.; Rodriguez, S.

2001-01-01

In 1989 was initiated at Rice Research Institute of Cuba, a mutation breeding programme, in order to obtain new germoplasm with improved characters such as milling quality, earliness, resistance to the Hoja Blanca virus disease and salt tolerance. Seven varieties has been irradiated and two different sources of radiation were used: gamma rays from 60Co and fast neutrons of a 14 MeV neutron generator. In 1995, was released the variety IACuba 23 for low inputs conditions. Another four varieties IACuba 21, IACuba 22, IACuba 27 and IACuba 28 are in validation trials in rice production areas under irrigated condition. The last two have showed resistance to Steneotarsonemus spinki. Also, a group of mutants was selected to be used as parents. These mutants have been used in 953 crosses

Genome wide re-sequencing of newly developed Rice Lines from common wild rice (Oryza rufipogon Griff.) for the identification of NBS-LRR genes.

Science.gov (United States)

Liu, Wen; Ghouri, Fozia; Yu, Hang; Li, Xiang; Yu, Shuhong; Shahid, Muhammad Qasim; Liu, Xiangdong

2017-01-01

Common wild rice (Oryza rufipogon Griff.) is an important germplasm for rice breeding, which contains many resistance genes. Re-sequencing provides an unprecedented opportunity to explore the abundant useful genes at whole genome level. Here, we identified the nucleotide-binding site leucine-rich repeat (NBS-LRR) encoding genes by re-sequencing of two wild rice lines (i.e. Huaye 1 and Huaye 2) that were developed from common wild rice. We obtained 128 to 147 million reads with approximately 32.5-fold coverage depth, and uniquely covered more than 89.6% (> = 1 fold) of reference genomes. Two wild rice lines showed high SNP (single-nucleotide polymorphisms) variation rate in 12 chromosomes against the reference genomes of Nipponbare (japonica cultivar) and 93-11 (indica cultivar). InDels (insertion/deletion polymorphisms) count-length distribution exhibited normal distribution in the two lines, and most of the InDels were ranged from -5 to 5 bp. With reference to the Nipponbare genome sequence, we detected a total of 1,209,308 SNPs, 161,117 InDels and 4,192 SVs (structural variations) in Huaye 1, and 1,387,959 SNPs, 180,226 InDels and 5,305 SVs in Huaye 2. A total of 44.9% and 46.9% genes exhibited sequence variations in two wild rice lines compared to the Nipponbare and 93-11 reference genomes, respectively. Analysis of NBS-LRR mutant candidate genes showed that they were mainly distributed on chromosome 11, and NBS domain was more conserved than LRR domain in both wild rice lines. NBS genes depicted higher levels of genetic diversity in Huaye 1 than that found in Huaye 2. Furthermore, protein-protein interaction analysis showed that NBS genes mostly interacted with the cytochrome C protein (Os05g0420600, Os01g0885000 and BGIOSGA038922), while some NBS genes interacted with heat shock protein, DNA-binding activity, Phosphoinositide 3-kinase and a coiled coil region. We explored abundant NBS-LRR encoding genes in two common wild rice lines through genome wide re

The improvement of cisantana rice variety through induced mutation

International Nuclear Information System (INIS)

Mugiono; Lilik Harsanti; Azri Kusuma Dewi

2009-01-01

The continuous improvement for rice through breeding is necessary to obtain new varieties with good quality and quantity. Cisantana variety hairy tips could be improved by mutation breeding. Seeds of Cisantana variety was irradiated by gamma rays ( 60 Co) at doses of 0.10, 0.20 and 0.30 kGy respectively at the Center for Application of Isotope and Radiation (CAIR) - Batan, Pasar Jumat, Jakarta. There after the irradiated seeds were planted as M1 plants at the CAIR’S experiment field in the dry season of 2000. Selection was carried out at the M2 generation and stressed on early maturity and bald spike. This was done at the experiment field at Pusakanegara - Subang in the Wet season of 2001/2002. From this population 19 mutants having early maturity and bald spike lets were selected. Purification in the next generation obtained 10 mutants which were homogeneous and without segregation. From these 10 mutants two mutant lines Obs-1688/PsJ and Obs-1692/PsJ were further tested. These two mutant lines showed good productivity and adaptability when tested at several locations. The resistance test for brown plant hopper and bacterial leaf blight disease showed that these two mutant lines are resistant to biotype 1 and 2, and medium resistant to biotype 3 of brown plant hopper, and also resistant to strain 3 and medium resistant to strain IV of bacterial leaf blight disease. These two mutant lines have good rice quality and were gelatinous. The Obs-1688/PsJ and Obs-1692/PsJ mutant lines were released as new rice varieties by the Minister of Agriculture and officially address as Mira-1 at 2006 and Bestari at 2008, respectively. (author)

Genetic analysis and gene fine mapping of aroma in rice (Oryza sativa L. Cyperales, Poaceae

Directory of Open Access Journals (Sweden)

Shu Xia Sun

2008-01-01

Full Text Available We investigated inheritance and carried out gene fine mapping of aroma in crosses between the aromatic elite hybrid rice Oryza sativa indica variety Chuanxiang-29B (Ch-29B and the non-aromatic rice O. sativa indica variety R2 and O. sativa japonica Lemont (Le. The F1 grains and leaves were non-aromatic while the F2 non-aroma to aroma segregation pattern was 3:1. The F3 segregation ratio was consistent with the expected 1:2:1 for a single recessive aroma gene in Ch-29B. Linkage analysis between simple sequence repeat (SSR markers and the aroma locus for the aromatic F2 plants mapped the Ch-29B aroma gene to a chromosome 8 region flanked by SSR markers RM23120 at 0.52 cM and RM3459 at 1.23 cM, a replicate F2 population confirming these results. Three bacterial artificial chromosome (BAC clones cover chromosome 8 markers RM23120 and RM3459. Our molecular mapping data from the two populations indicated that the aroma locus occurs in a 142.85 kb interval on BAC clones AP005301 or AP005537, implying that it might be the same gene reported by Bradbury et al (2005a; Plant Biotec J. 3:363-370. The flanking markers Aro7, RM23120 and RM3459 identified by us could greatly accelerate the efficiency and precision of aromatic rice breeding programs.

Plant breeding and genetics newsletter. No. 10

International Nuclear Information System (INIS)

2003-01-01

training courses were held in Algeria, Kenya, Malaysia, Macedonia, Sri Lanka, Vietnam, Yemen and Zambia. In the Plant Breeding Unit, Seibersdorf activities focused on identifying putative rice mutants with tolerance to salinity and of polymorphism in salt tolerant rice mutants and on collection of the first mutants in an organized Mutants Repository

Plant breeding with marker-assisted selection in Brazil

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Ney Sussumu Sakiyama

2014-03-01

Full Text Available Over the past three decades, molecular marker studies reached extraordinary advances, especially for sequencing and bioinformatics techniques. Marker-assisted selection became part of the breeding program routines of important seed companies, in order to accelerate and optimize the cultivar developing processes. Private seed companies increasingly use marker-assisted selection, especially for the species of great importance to the seed market, e.g. corn, soybean, cotton, and sunflower. In the Brazilian public institutions few breeding programs use it efficiently. The possible reasons are: lack of know-how, lack of appropriate laboratories, few validated markers, high cost, and lack of urgency in obtaining cultivars. In this article we analyze the use and the constraints of marker-assisted selection in plant breeding programs of Brazilian public institutes

Two whitebacked planthopper resistance genes in rice share the same loci with those for brown planthopper resistance.

Science.gov (United States)

Tan, G X; Weng, Q M; Ren, X; Huang, Z; Zhu, L L; He, G C

2004-03-01

The whitebacked planthopper (WBPH), Sogatella furcifera, and brown planthopper (BPH) Nilaparvata lugens Stål are important sucking insects of rice (Oryza sativa L.) crops throughout the world. Rice 'B5', which has derived its resistance genes from the wild rice O. officinalis Wall ex Watt, is a line that is highly resistant to both WBPH and BPH. Previously, two resistance genes against BPH, Qbp1, and Qbp2 in 'B5' had been mapped onto chromosome 3 and chromosome 4, respectively. In this study, we employed a mapping population composed of 187 recombinant inbred lines (RILs), produced from a cross between 'B5' and susceptible variety 'Minghui63', to locate the WBPH and BPH resistance genes. A RFLP survey of the bulked extremes from the RIL population identified two genomic regions, one on chromosome 3 and the other on chromosome 4, likely containing the resistance genes to planthoppers. QTL analysis of the RILs further confirmed that two WBPH resistance genes were mapped on the same loci as Qbp1 and Qbp2, using a linkage map with 242 molecular markers distributed on 12 rice chromosomes. Of the two WBPH resistance genes, one designated Wbph7(t) was located within a 1.1-cM region between R1925 and G1318 on chromosome 3, the other designated Wbph8(t) was within a 0.3-cM region flanked by R288 and S11182 on chromosome 4. A two-way analysis of variance showed that two loci acted independently with each other in determining WBPH resistance. The results have significant implications in studying the interactions between sucking insects and plants and in breeding programs of resistance to rice planthoppers.

Significance, progress and prospects for research in simplified cultivation technologies for rice in China.

Science.gov (United States)

Huang, M; Ibrahim, Md; Xia, B; Zou, Y

2011-08-01

Simplified cultivation technologies for rice have become increasingly attractive in recent years in China because of their social, economical and environmental benefits. To date, several simplified cultivation technologies, such as conventional tillage and seedling throwing (CTST), conventional tillage and direct seeding (CTDS), no-tillage and seedling throwing (NTST), no-tillage and direct seeding (NTDS) and no-tillage and transplanting (NTTP), have been developed in China. Most studies have shown that rice grown under each of these simplified cultivation technologies can produce a grain yield equal to or higher than traditional cultivation (conventional tillage and transplanting). Studies that have described the influences of agronomic practices on yield formation of rice under simplified cultivation have demonstrated that optimizing agronomy practices would increase the efficiencies of simplified cultivation systems. Further research is needed to optimize the management strategies for CTST, CTDS and NTST rice which have developed quickly in recent years, to strengthen basic research for those simplified cultivation technologies that are rarely used at present (such as NTTP and NTDS), to select and breed cultivars suitable for simplified cultivation and to compare the practicability and effectiveness of different simplified cultivation technologies in different rice production regions.

Semen quality of Italian local pig breeds

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G. Gandini

2010-01-01

Full Text Available From 1996 to 1999 a conservation programme was carried out within the framework of EC contract “European gene banking project for the pig genetic resources” (Ollivier et al., 2001 in the Italian local pig breeds. The aims of the program included the primary characterization of the breeds, i.e. information on the organization in charge of the breed, breeding population numbers, breed description and qualifications, and field trials on productive and reproductive performances. In this context the “Semen Bank of Italian local pig breeds” was built. A total of 30,835 straws of four Italian local pig breeds (Cinta Senese, Casertana, Mora Romagnola and Nero Siciliano, collected from 42 sires, have been stored. In this work semen quality traits, lipid composition and freezability of the four Italian local pig breeds are reported.

Genetic Parameters and the Impact of Off-Types for Theobroma cacao L. in a Breeding Program in Brazil

Science.gov (United States)

DuVal, Ashley; Gezan, Salvador A.; Mustiga, Guiliana; Stack, Conrad; Marelli, Jean-Philippe; Chaparro, José; Livingstone, Donald; Royaert, Stefan; Motamayor, Juan C.

2017-01-01

Breeding programs of cacao (Theobroma cacao L.) trees share the many challenges of breeding long-living perennial crops, and genetic progress is further constrained by both the limited understanding of the inheritance of complex traits and the prevalence of technical issues, such as mislabeled individuals (off-types). To better understand the genetic architecture of cacao, in this study, 13 years of phenotypic data collected from four progeny trials in Bahia, Brazil were analyzed jointly in a multisite analysis. Three separate analyses (multisite, single site with and without off-types) were performed to estimate genetic parameters from statistical models fitted on nine important agronomic traits (yield, seed index, pod index, % healthy pods, % pods infected with witches broom, % of pods other loss, vegetative brooms, diameter, and tree height). Genetic parameters were estimated along with variance components and heritabilities from the multisite analysis, and a trial was fingerprinted with low-density SNP markers to determine the impact of off-types on estimations. Heritabilities ranged from 0.37 to 0.64 for yield and its components and from 0.03 to 0.16 for disease resistance traits. A weighted index was used to make selections for clonal evaluation, and breeding values estimated for the parental selection and estimation of genetic gain. The impact of off-types to breeding progress in cacao was assessed for the first time. Even when present at <5% of the total population, off-types altered selections by 48%, and impacted heritability estimations for all nine of the traits analyzed, including a 41% difference in estimated heritability for yield. These results show that in a mixed model analysis, even a low level of pedigree error can significantly alter estimations of genetic parameters and selections in a breeding program. PMID:29250097

Analysis of a brittle-culm mutant of rice (Oryza sativa) induced bay gamma rays

International Nuclear Information System (INIS)

Doat, Jacqueline; Marie, R.

1977-01-01

An unexpected ''brittle-culm'' mutant has been screened in the progeny of the rice cultivar ''Balilla 28'' after a seed treatment by gamma rays from a Cobalt-60 source. This property proved hereditable and true-breeding. It does not affect the high resistance to lodging of rice plants. Important difference were pointed out between control and mutant lines in cellulose content and 1 p. cent NaOH extracts: ''brittle-culm'' straw contains less cellulose and shows a degradation of glucid coupounds. The brittleness of plant tissues appears to be correlated with a partial depolymerization of cellulose, associated with a possible transformation from alpha- to beta- or gamma-cellulose [fr

Impact of selective breeding on European aquaculture

NARCIS (Netherlands)

Janssen, K.; Chavanne, H.; Berentsen, P.; Komen, H.

2017-01-01

Objectives of this study were to determine the combined market share of breeding companies in aquaculture production in Europe, to describe the main characteristics of breeding companies and their programs, and to provide per species estimates on cumulative genetic gain in growth performance.

SNP Polymorphism Survey of the Parental Lines of ISRA Sorghum Breeding Program as Part of the Feed the Future

Data.gov (United States)

US Agency for International Development — Polymorphism of SNP Markers (single nucleotide polymorphisms) was assessed on 24 parental lines of the ISRA sorghum breeding program . About 1300 SNP have been used...

Competitive and Allelopathic Effects of Wild Rice Accessions (Oryza longistaminata) at Different Growth Stages.

Science.gov (United States)

Shen, Shicai; Xu, Gaofeng; Clements, David Roy; Jin, Guimei; Zhang, Fudou; Tao, Dayun; Xu, Peng

2016-01-01

The competitive and allelopathic effects of wild rice (Oryza longistaminata) accessions on barnyard grass at different growth stages determined by days after sowing (0, 30, 60 and 90 days) were studied in greenhouse pot experiments. Wild rice accession RL159 exhibited the greatest height and tillering. The weed suppression rates of wild rice accessions OL and F1 on barnyard grass were significantly higher than for other rice accessions, with the lowest being O. sativa cultivar RD23. The highest suppression rates of OL and F1 were 80.23 and 73.96% at barnyard grass growth stages of 90 days and 60 days. At a 90 growth stage, wild rice accessions RL159 and RL169 caused 61.33 and 54.51% inhibition in barnyard grass growth, respectively. Under the same conditions, the competitive inhibition rates of OL, F1, RL159, RL169 and RL219 against barnyard grass were markedly lower than their weed suppressive effects, but were relatively similar for RD23. The allelopathic inhibition of OL and F1 on barnyard grass was significantly higher than other rice accessions. The highest allelopathic rates of OL and F1 were 60.61 and 56.87% at the 0 day growth stage. It is concluded that wild rice accessions OL and F1 exhibited the highest allelopathic activity along with moderate competitive ability against barnyard grass; wild rice accession RL159 had the highest competitive ability and moderate allelopathic activity on barnyard grass. Thus, the three wild rice accessions OL, F1 and RL159 could be used as ideal breeding materials for cultivated rice improvement.

Mutations induced in plant breeding

International Nuclear Information System (INIS)

Barriga B, P.

1984-01-01

The most significant aspects of the use of ionizing radiations in plant breeding are reviewed. Aspects such as basic principles of mutation, expression and selection in obtention of mutants, methods for using induced mutations and sucess achieved with this methodology in plant breeding are reviewed. Results obtained in a program of induced mutation on wheat for high content of protein and lysine at the Universidad Austral de Chile are presented. (Author)

Mutations induced in plant breeding

Energy Technology Data Exchange (ETDEWEB)

Barriga B, P. (Universidad Austral de Chile, Valdivia. Inst. de Produccion y Sanidad Vegetal)

1984-10-01

The most significant aspects of the use of ionizing radiations in plant breeding are reviewed. Aspects such as basic principles of mutation, expression and selection in obtention of mutants, methods for using induced mutations and sucess achieved with this methodology in plant breeding are reviewed. Results obtained in a program of induced mutation on wheat for high content of protein and lysine at the Universidad Austral de Chile are presented.

Pollen Sterility—A Promising Approach to Gene Confinement and Breeding for Genetically Modified Bioenergy Crops

Directory of Open Access Journals (Sweden)

Albert P. Kausch

2012-10-01

Full Text Available Advanced genetic and biotechnology tools will be required to realize the full potential of food and bioenergy crops. Given current regulatory concerns, many transgenic traits might never be deregulated for commercial release without a robust gene confinement strategy in place. The potential for transgene flow from genetically modified (GM crops is widely known. Pollen-mediated transfer is a major component of gene flow in flowering plants and therefore a potential avenue for the escape of transgenes from GM crops. One approach for preventing and/or mitigating transgene flow is the production of trait linked pollen sterility. To evaluate the feasibility of generating pollen sterility lines for gene confinement and breeding purposes we tested the utility of a promoter (Zm13Pro from a maize pollen-specific gene (Zm13 for driving expression of the reporter gene GUS and the cytotoxic gene barnase in transgenic rice (Oryza sativa ssp. Japonica cv. Nipponbare as a monocot proxy for bioenergy grasses. This study demonstrates that the Zm13 promoter can drive pollen-specific expression in stably transformed rice and may be useful for gametophytic transgene confinement and breeding strategies by pollen sterility in food and bioenergy crops.

Divergent Hd1, Ghd7, and DTH7 Alleles Control Heading Date and Yield Potential of Japonica Rice in Northeast China.

Science.gov (United States)

Ye, Jing; Niu, Xiaojun; Yang, Yaolong; Wang, Shan; Xu, Qun; Yuan, Xiaoping; Yu, Hanyong; Wang, Yiping; Wang, Shu; Feng, Yue; Wei, Xinghua

2018-01-01

The heading date is a vital factor in achieving a full rice yield. Cultivars with particular flowering behaviors have been artificially selected to survive in the long-day and low-temperature conditions of Northeast China. To dissect the genetic mechanism responsible for heading date in rice populations from Northeast China, association mapping was performed to identify major controlling loci. A genome-wide association study (GWAS) identified three genetic loci, Hd1 , Ghd7 , and DTH7 , using general and mixed linear models. The three genes were sequenced to analyze natural variations and identify their functions. Loss-of-function alleles of these genes contributed to early rice heading dates in the northern regions of Northeast China, while functional alleles promoted late rice heading dates in the southern regions of Northeast China. Selecting environmentally appropriate allele combinations in new varieties is recommended during breeding. Introducing the early indica rice's genetic background into Northeast japonica rice is a reasonable strategy for improving genetic diversity.

Plant mutation breeding for crop improvement. V.2

International Nuclear Information System (INIS)

1991-01-01

This volume contains the proceedings of the final two sessions of the FAO/IAEA Symposium on Plant Mutation Breeding for Crop Improvement, focussing on mutation breeding with particular objectives and the methodology of mutation breeding. The individual contributions are indexed separately. Although a wide variety of topics is included, the emphasis is on the use of (mainly gamma) radiation to induce economically useful mutants in cereals and legumes. The results of many conventional plant breeding programs are also presented. Refs, figs and tabs

Plant mutation breeding for crop improvement. V.1

International Nuclear Information System (INIS)

1991-01-01

This volume contains the proceedings of the first two sessions of the FAO/IAEA Symposium on Plant Mutation Breeding for Crop Improvement, focussing on mutation breeding in particular countries and crop-specific mutation breeding. The individual contributions are indexed separately. Although a wide variety of topics is included, the emphasis is on the use of (mainly gamma) radiation to induce economically useful mutants in cereals and legumes. The results of many conventional plant breeding programs are also presented. Refs, figs and tabs

Optimizing the creation of base populations for aquaculture breeding programs using phenotypic and genomic data and its consequences on genetic progress.

Science.gov (United States)

Fernández, Jesús; Toro, Miguel Á; Sonesson, Anna K; Villanueva, Beatriz

2014-01-01

The success of an aquaculture breeding program critically depends on the way in which the base population of breeders is constructed since all the genetic variability for the traits included originally in the breeding goal as well as those to be included in the future is contained in the initial founders. Traditionally, base populations were created from a number of wild strains by sampling equal numbers from each strain. However, for some aquaculture species improved strains are already available and, therefore, mean phenotypic values for economically important traits can be used as a criterion to optimize the sampling when creating base populations. Also, the increasing availability of genome-wide genotype information in aquaculture species could help to refine the estimation of relationships within and between candidate strains and, thus, to optimize the percentage of individuals to be sampled from each strain. This study explores the advantages of using phenotypic and genome-wide information when constructing base populations for aquaculture breeding programs in terms of initial and subsequent trait performance and genetic diversity level. Results show that a compromise solution between diversity and performance can be found when creating base populations. Up to 6% higher levels of phenotypic performance can be achieved at the same level of global diversity in the base population by optimizing the selection of breeders instead of sampling equal numbers from each strain. The higher performance observed in the base population persisted during 10 generations of phenotypic selection applied in the subsequent breeding program.

Nicaragua - Rice and Banana Farmers

Data.gov (United States)

Millennium Challenge Corporation — This report is an impact evaluation of two components of the Rural Business Development Program (RBD) in Nicaragua, specifically the components benefitting rice and...

Breeding performance in the Italian chicken breed Mericanel della Brianza

Directory of Open Access Journals (Sweden)

Stefano P. Marelli

2010-11-01

Full Text Available In Italy, 90 local avian breeds were described, the majority (61% were classified extinct and only 8.9 % still diffused. Therefore, efforts for conservation of Italian avian breeds are urgently required. The aim of this study was to record the breeding performance of the Italian breed Mericanel della Brianza and multiply a small population, in order to develop a conservation program. Fourteen females and 8 males were available at the beginning of the reproductive season in 2009 and organized in 8 families (1 male/1-2 females kept in floor pens. Birds received a photoperiod of 14L:10D and fed ad libitum. Breeding performance was recorded from March to June. Egg production and egg weight were recorded daily; eggs were set every 2 weeks and fertility, embryo mortality and hatchability were recorded. Mean egg production was 37% and mean egg weight was 34±3.49 g. High fertility values were recorded in the first three settings, from 94 to 87%, and the overall mean fertility value was 81.6%. Overall hatchability was only 49.6% due to a high proportion of dead embryos. Embryo mortality occurred mainly between day 2 and 7 of incubation and during hatch. Highest hatchability values were recorded in setting 1 and 2, 69 and 60% respectively, and a great decrease was found in the following settings. Great variations in egg production, fertility, hatchability and embryo mortality were found among families. The present results are the basic knowledge on reproductive parameters necessary to improve the reproductive efficiency of the breed within a conservation plan.

Rice improvement, involving altered flower structure more suitable to cross-pollination, using in vitro culture in combination with mutagenesis

International Nuclear Information System (INIS)

Min, S.K.

1998-01-01

Anther and somatic tissue culture in combination with mutagenesis were carried out to evaluate the efficiency of different mutagenic treatments of various in vitro culture materials, and to obtain some promising variants for rice improvement. Results indicated that in japonica rice radiation treatment of dry seeds and young panicles influenced the percentage of green plantlets regeneration from anther culture. Both treatments increased significantly the percentage of regenerated green plantlets in comparison with the control. Irradiation with 30 Gy of rice callus increased also the percentage of regenerated green plantlets. For indica rice, the combination of the suitable dose of gamma rays irradiation on seeds and an improved medium, increased the percentage of callus induction. This approach made it possible to use anther culture in indica rice breeding. Somatic tissue cultures combined with radiation-induced mutagenesis led to the development of a number of promising mutants including some new cytoplasm-nucleus interacting male-sterile lines with almost 100% stigma exertion. Their development would be of practical significance for increasing the genetic diversity for production of hybrid rice. (author)

Tagging of blast resistance gene(s) to DNA markers and marker-assisted selection (MAS) in rice improvement

International Nuclear Information System (INIS)

Zhuang, J.Y.; Lu, J.; Qian, H.R.; Lin, H.X.; Zheng, K.L.

1998-01-01

This paper reports progress made on the tagging of blast resistance gene(s) to DNA markers and on the initiation of marker-assisted selection (MAS) for blast resistance in rice improvement. A pair of near isogenic lines, K8OR and K79S, were developed using a Chinese landrace Hong-jiao-zhan as the resistance donor. Ten putatively positive markers were identified by screening 177 mapped DNA markers. Using the F 2 population of 143 plants and the derived F 3 lines, three Restriction Fragment Length Polymorphism (RFLP) markers (RG81, RG869 and RZ397) on chromosome 12 of rice were identified to be closely linked to the blast resistance gene Pi-12(t). The genetic distance between Pi-12(t) and the closest marker RG869 was 5.1 cM. By employing the bulk segregant analysis (BSA) procedure, six of 199 arbitrary primers were found to produce positive Randomly Amplified Polymorphic DNA (RAPD) bands. Tight linkage between Pi-12(t) and three RAPD bands, each from a different primer, was confirmed after amplification of DNA of all F 2 individuals. Two fragments were cloned and sequenced, and two sequence characterised amplified re-ion (SCAR) markers were established. In two other F 3 populations, Xian-feng I/Tetep and Xian-feng, 1/Hong-jiao-zhan, the blast resistance was found to be controlled by interactions of two or more genes. One resistance gene was located in the vicinity of RG81 in both populations. Work to identify other gene(s) is currently under way. Marker assisted selection for blast resistance was initiated. Crosses were made between elite varieties and blast resistance donors to develop populations for DNA marker-assisted selection of blast resistance. In addition, 48 varieties widely used in current rice breeding programs were provided by rice breeders. DNA marker-based polymorphism among, these varieties and resistance donors were analysed to produce a database for future MAS program. (author)

Improving Blast Resistance of a Thermo-Sensitive Genic Male Sterile Rice Line GD-8S by Molecular Marker-Assisted Selection

Directory of Open Access Journals (Sweden)

Wu-ge LIU

2008-09-01

Full Text Available The broad-spectrum blast resistance gene Pi-1, from donor line BL122, was introduced into a thermo-sensitive genic male sterile rice line GD-8S, which possessed good grain quality but high susceptibility to rice blast, by using backcross breeding and molecular marker-assisted selection. Five elite improved male sterile lines, RGD8S-1, RGD8S-2, RGD8S-3, RGD8S-4 and RGD8S-5, were selected based on the results of molecular marker analysis, spikelet sterility, recovery rate of genetic background and agronomic traits. Thirty-three representative blast isolates collected from Guangdong Province, China were used to inoculate the improved lines and the original line GD-8S artificially. The resistance frequencies of the improved lines ranged from 76.47% to 100%, much higher than that of the original line GD-8S (9.09%. On the agronomic characters, there were no significant differences between the improved lines and GD-8S except for flag leaf length and panicle number per plant. The improved lines could be used for breeding hybrid rice with high blast resistance.

Plant breeding and genetics newsletter. No. 9

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-07-01

There have been a number of important events related to the activity of the Plant Breeding and Genetics sub-programme in the past six months. The joint FAO/IAEA RCMs on 'Molecular characterization of mutated genes controlling important traits for seed crop improvement' and 'Mutational analysis of root characters in annual food plants related to plant performance' were held in June, in Krakow, Poland. It was the third RCM of the CRP on crop plant genomics and the second in the CRP on root systems. More than 40 scientists from twenty countries participated in the meeting. Significant progress was achieved in presented projects of diverse areas of both CRPs. Although genomics and root genetics are methodologically among the most rapidly developing disciplines, the participants successfully tried to follow the latest developments. The Consultants Meeting on 'Physical mapping technologies for the identification and characterization of mutated genes contributing to crop quality' was also held in June, in Vienna. Physical mapping technologies provide new tools for the rapid advancement of breeding programs and are highly applicable to neglected crops in developing countries. Furthermore, they open new opportunities for developing modern approaches to plant improvement research. Consultants recommended the organization of a Co-ordinated Research Project dealing with application of these new technologies to breeding programmes with the use of induced mutations for crop improvement. It is expected that the new CRP will be initiated this year. In close collaboration with EU COST 851 'Gametic cells and molecular breeding for crop improvement' project we started with preparation and editing of a book on 'Doubled haploid production in crop plants. A manual'. More than 40 manuscripts were collected, reviewed by a team of EU COST 851 experts and are now in the final editing phase. Similarly, we finished editorial work on publishing the training material from the FAO/IAEA Training

Plant breeding and genetics newsletter. No. 9

International Nuclear Information System (INIS)

2002-07-01

There have been a number of important events related to the activity of the Plant Breeding and Genetics sub-programme in the past six months. The joint FAO/IAEA RCMs on 'Molecular characterization of mutated genes controlling important traits for seed crop improvement' and 'Mutational analysis of root characters in annual food plants related to plant performance' were held in June, in Krakow, Poland. It was the third RCM of the CRP on crop plant genomics and the second in the CRP on root systems. More than 40 scientists from twenty countries participated in the meeting. Significant progress was achieved in presented projects of diverse areas of both CRPs. Although genomics and root genetics are methodologically among the most rapidly developing disciplines, the participants successfully tried to follow the latest developments. The Consultants Meeting on 'Physical mapping technologies for the identification and characterization of mutated genes contributing to crop quality' was also held in June, in Vienna. Physical mapping technologies provide new tools for the rapid advancement of breeding programs and are highly applicable to neglected crops in developing countries. Furthermore, they open new opportunities for developing modern approaches to plant improvement research. Consultants recommended the organization of a Co-ordinated Research Project dealing with application of these new technologies to breeding programmes with the use of induced mutations for crop improvement. It is expected that the new CRP will be initiated this year. In close collaboration with EU COST 851 'Gametic cells and molecular breeding for crop improvement' project we started with preparation and editing of a book on 'Doubled haploid production in crop plants. A manual'. More than 40 manuscripts were collected, reviewed by a team of EU COST 851 experts and are now in the final editing phase. Similarly, we finished editorial work on publishing the training material from the FAO/IAEA Training

[Impacts of climate warming on growth period and yield of rice in Northeast China during recent two decades].

Science.gov (United States)

Hou, Wen-jia; Geng, Ting; Chen, Qun; Chen, Chang-qing

2015-01-01

By using rice growth period, yield and climate observation data during the recent two decades, the impact of climate warming on rice in Northeast China was investigated by mathematical statistics methods. The results indicated that in the three provinces of Northeast China, the average, maximum and minimum temperatures in rice growing season were on the. rise, and the rainfall presented a downward trend during 1989-2009. Compared to 1990s, the rice whole growth periods of Heilongjiang, Jilin and Liaoning provinces in 2000s were prolonged 14 d, 4.5 d and 5.1 d, respectively. The increase of temperature in May, June and September could extend the rice growth period, while that in July would shorten the growth duration. The rice growth duration of registered varieties and experiment sites had a similar increasing trend in Northeast China except for the Heilongjiang Province, and the extension of registered varieties growth period was the main factor causing the prolonged growth period of rice at experiment sites. The change in daily average, minimum and maximum temperatures all could affect the rice yield in Northeast China. The increasing temperature significantly increased the rice yield in Heilongjiang Province, especially in the west region of Sanjiang Plain. Except for the south of Liaoning Province, rice yields in other regions of Northeast China were promoted by increasing temperature. Proper measures for breeding, cultivation and farming, could be adopted to fully improve the adaptation of rice to climate warming in Northeast China.

Efficient Breeding by Genomic Mating.

Science.gov (United States)

Akdemir, Deniz; Sánchez, Julio I

2016-01-01

Selection in breeding programs can be done by using phenotypes (phenotypic selection), pedigree relationship (breeding value selection) or molecular markers (marker assisted selection or genomic selection). All these methods are based on truncation selection, focusing on the best performance of parents before mating. In this article we proposed an approach to breeding, named genomic mating, which focuses on mating instead of truncation selection. Genomic mating uses information in a similar fashion to genomic selection but includes information on complementation of parents to be mated. Following the efficiency frontier surface, genomic mating uses concepts of estimated breeding values, risk (usefulness) and coefficient of ancestry to optimize mating between parents. We used a genetic algorithm to find solutions to this optimization problem and the results from our simulations comparing genomic selection, phenotypic selection and the mating approach indicate that current approach for breeding complex traits is more favorable than phenotypic and genomic selection. Genomic mating is similar to genomic selection in terms of estimating marker effects, but in genomic mating the genetic information and the estimated marker effects are used to decide which genotypes should be crossed to obtain the next breeding population.

Impacts of Nutrition and Feeding Programs on Farmers’ Management Decisions Affecting the Success of Dairy Farms with Culture Breed Cattle

OpenAIRE

Yavuz Topcu; Mehmet Toparlak; Muhlis Macit

2016-01-01

The aim of the study is to evaluate all the factors determining the milk production and yield decisions with regard to the nutrition and feeding programs affecting the integrated management strategies on the success of the dairy farms with culture breed cattle under the pasture-based and indoor barn-based production systems. For these aims, data obtained from the individual interviews conducted at the dairy farms with 100 culture breed cattle were used for Principal Component and Multiple Reg...

Chloroplast-expressed MSI-99 in tobacco improves disease resistance and displays inhibitory effect against rice blast fungus.

Science.gov (United States)

Wang, Yun-Peng; Wei, Zheng-Yi; Zhang, Yu-Ying; Lin, Chun-Jing; Zhong, Xiao-Fang; Wang, Yue-Lin; Ma, Jing-Yong; Ma, Jian; Xing, Shao-Chen

2015-03-02

Rice blast is a major destructive fungal disease that poses a serious threat to rice production and the improvement of blast resistance is critical to rice breeding. The antimicrobial peptide MSI-99 has been suggested as an antimicrobial peptide conferring resistance to bacterial and fungal diseases. Here, a vector harboring the MSI-99 gene was constructed and introduced into the tobacco chloroplast genome via particle bombardment. Transformed plants were obtained and verified to be homoplastomic by PCR and Southern hybridization. In planta assays demonstrated that the transgenic tobacco plants displayed an enhanced resistance to the fungal disease. The evaluation of the antimicrobial activity revealed that the crude protein extracts from the transgenic plants manifested an antimicrobial activity against E. coli, even after incubation at 120 °C for 20 min, indicating significant heat stability of MSI-99. More importantly, the MSI-99-containing protein extracts were firstly proved in vitro and in vivo to display significant suppressive effects on two rice blast isolates. These findings provide a strong basis for the development of new biopesticides to combat rice blast.

Chloroplast-Expressed MSI-99 in Tobacco Improves Disease Resistance and Displays Inhibitory Effect against Rice Blast Fungus

Directory of Open Access Journals (Sweden)

Yun-Peng Wang

2015-03-01

Full Text Available Rice blast is a major destructive fungal disease that poses a serious threat to rice production and the improvement of blast resistance is critical to rice breeding. The antimicrobial peptide MSI-99 has been suggested as an antimicrobial peptide conferring resistance to bacterial and fungal diseases. Here, a vector harboring the MSI-99 gene was constructed and introduced into the tobacco chloroplast genome via particle bombardment. Transformed plants were obtained and verified to be homoplastomic by PCR and Southern hybridization. In planta assays demonstrated that the transgenic tobacco plants displayed an enhanced resistance to the fungal disease. The evaluation of the antimicrobial activity revealed that the crude protein extracts from the transgenic plants manifested an antimicrobial activity against E. coli, even after incubation at 120 °C for 20 min, indicating significant heat stability of MSI-99. More importantly, the MSI-99-containing protein extracts were firstly proved in vitro and in vivo to display significant suppressive effects on two rice blast isolates. These findings provide a strong basis for the development of new biopesticides to combat rice blast.

Physiological Age Status of Female Adults and Off-Season Survival of Rice Leaffolder Cnaphalocrocis medinalis in India

Directory of Open Access Journals (Sweden)

Padmavathi Chintalapati

2015-09-01

Full Text Available Rice leaffolder, Cnaphalocrocis medinalis, is one of the major foliage feeders found in the rice growing regions in India. When the crop was at maturity, numerous adults of rice leaffolder were found in the rice fields though the larval population gradually decreased, and no eggs were found on rice leaves. The population characteristics of C. medinalis were assessed based on the physiological age status of adults at different crop growth stages. Based on egg development within ovarioles, ovariole appearance, number and colour of fat bodies, and characteristics of bursa copulatrix, physiological age status of the adults was described, which served as a basis for the determination of age composition. C. medinalis adults were found during the first week of August on rice plants, of which 44% were in Age 0 with immature ovaries, indicating immigrants. However, 28% adults each were at Ages 1–2 with developing ovaries, indicating local breeding population. The carryover and off-season survival of C. medinalis were also studied to determine the contribution of the alternative hosts in the population growth that helped in devising efficient management strategies. Rice was the most preferred host followed by Triticum aestivum, Echinochloa crusgulli and Brachiaria plantaginea. Various routes of the carryover of C. medinalis from season to season were discussed.

Geographic and research center origins of rice resistance to asian planthoppers and leafhoppers: implications for rice breeding and gene deployment

OpenAIRE

Horgan, F.G.; Srinivasan, Thanga Suja; Bentur, Jagadish S.; Kumar, R.; Bhanu, K.V.; Singh Sarao, Preetinder; Chien, Ho Van; Almazan, M.L.P.; Bernal, Carmencita C.; Ramal, Angelee Fame; Ferrater, J.B.; Huang, Shou Horng

2017-01-01

This study examines aspects of virulence to resistant rice varieties among planthoppers and leafhoppers. Using a series of resistant varieties, brown planthopper, Nilaparvata lugens, virulence was assessed in seedlings and early-tillering plants at seven research centers in South and East Asia. Virulence of the whitebacked planthopper, Sogatella furcifera, in Taiwan and the Philippines was also assessed. Phylogenetic analysis of the varieties using single-nucleotide polymorphisms (SNPs) indic...

Comparison study of genetic diversity between rice varieties from northeast China and Japan

International Nuclear Information System (INIS)

Li Hongyu; Wang Haize; Zhang Longhai; Liu Menghong; Xu Zhengjin; Zhao Minghui; Xu Hai; Wang Jiayu; Si Yang

2011-01-01

The genetic diversity of 18 rice varieties from northeast China and 13 rice varieties from Japan were investigated by 20 phenotypic traits and SSR assay with 40 pairs of primers. The results showed that 82 phenotypic variation and 108 alleles were detected. With an average of 2.54 alleles on every locus the phenotypic variation and alleles in northeast China were 72 and 103, respectively, and 63 and 94 were respectively with an average of 2.32 alleles on every locus in Japanese varieties. Genetic variation among different varieties varied greatly and among different groups varied slightly. Genetic diversity of varieties in northeast China was much higher than those in Japan, and 94.7% of the alleles from Japanese varieties were included in the varieties from northeast China. The available specific alleles were already very limited in the varieties from Japan and can not meet the rice breeding requirements for northeastern China. (authors)

New approach to increasing rice lodging resistance and biomass yield through the use of high gibberellin producing varieties.

Science.gov (United States)

Okuno, Ayako; Hirano, Ko; Asano, Kenji; Takase, Wakana; Masuda, Reiko; Morinaka, Yoichi; Ueguchi-Tanaka, Miyako; Kitano, Hidemi; Matsuoka, Makoto

2014-01-01

Traditional breeding for high-yielding rice has been dependent on the widespread use of fertilizers and the cultivation of gibberellin (GA)-deficient semi-dwarf varieties. The use of semi-dwarf plants facilitates high grain yield since these varieties possess high levels of lodging resistance, and thus could support the high grain weight. Although this approach has been successful in increasing grain yield, it is desirable to further improve grain production and also to breed for high biomass. In this study, we re-examined the effect of GA on rice lodging resistance and biomass yield using several GA-deficient mutants (e.g. having defects in the biosynthesis or perception of GA), and high-GA producing line or mutant. GA-deficient mutants displayed improved bending-type lodging resistance due to their short stature; however they showed reduced breaking-type lodging resistance and reduced total biomass. In plants producing high amounts of GA, the bending-type lodging resistance was inferior to the original cultivars. The breaking-type lodging resistance was improved due to increased lignin accumulation and/or larger culm diameters. Further, these lines had an increase in total biomass weight. These results show that the use of rice cultivars producing high levels of GA would be a novel approach to create higher lodging resistance and biomass.

The relationship between Anopheles gambiae density and rice cultivation in the savannah zone and forest zone of Côte d'Ivoire.

Science.gov (United States)

Briët, Olivier J T; Dossou-Yovo, Joel; Akodo, Elena; van de Giesen, Nick; Teuscher, Thomas M

2003-05-01

In 13 villages in the savannah zone and 21 villages in the forest zone of Côte d'Ivoire, the biting density of the principal malaria vector, Anopheles gambiae, was studied as a function of rice cultivation in the inland valleys in a 2-km radius around each village. In the savannah villages, during the main season cropping period, surface water on rice-cultivated and to a lesser extent on uncultivated inland valleys seems to contribute strongly to the A. gambiae population density. For the off-season cropping period (which starts after the first light rains in the savannah zone), correlations were weaker. Breeding sites other than in inland valleys may play an important role in the savannah zone. In the forest zone, however, the A. gambiae population density was strongly correlated with the surface water availability (SWA) in the rice-cultivated inland valleys, whereas the correlation with the SWA in other (uncultivated) inland valleys was weak. The requirement of sunlit breeding sites for A. gambiae might explain this difference between zones. In the forest zone, only inland valleys cleared for rice cultivation meet this requirement, whereas all other inland valleys are covered with dense vegetation. In the savannah zone, however, most undergrowth is burnt during the dry season, which permits sunlight to reach puddles resulting from the first rains.

Rice Physicist to direct $40M LHC Program

CERN Multimedia

2006-01-01

"Rice Universty announced that physicist B. Paul Padley has been chosen to lead the scientific operations for one of the particle detector systems at the European Organization for Nuclear Research's Large Hadron Collider (LHC)."

A Single Recessive Mutated Gene (Sd237-1) Controlling Semi-Dwarf Plant Stature of Rice

International Nuclear Information System (INIS)

Sobrizal

2009-01-01

Dwarfism is a valuable trait in crop breeding, because it increases lodging resistance and decreases damages due to wind and rain. During the course of this study, a semi-dwarf mutant was successfully induced through 200 Gy gamma ray irradiated KI 237 seeds. KI 237 is a pure line with high yield potency, developed through an Indica-Japonica cross of IR36 / Koshihikari. The selected semi-dwarf plant reached 60 - 62 % of plant height of original plant KI 237 at the mature stage. The length of inter nodes, panicle, and seed were also compared between these two plants. The retardation of the 1 st (uppermost) inter nodes was 24 %, moreover, the retardation of panicle and seed length were only 10 % and 2 %, respectively. The elongation pattern of the inter nodes in this mutant was almost the same as sd1 (Dee-geo-woo-gen), the original parent of the first release modern rice variety, but their performances were different. Based on the segregation analysis in M 2 and M 3 generation it was concluded that this mutant was controlled by a single recessive mutated gene. This gene was designated as sd 237-1 . This mutant should be useful as a genetic resource for the improvement of KI 237 line through back-cross breeding as well as be developed further in breeding program directly to be a new high yielding mutant variety. (author)

Revisiting GMOs: Are There Differences in European Consumers' Acceptance and Valuation for Cisgenically vs Transgenically Bred Rice?

Directory of Open Access Journals (Sweden)

Anne-Cécile Delwaide

Full Text Available Both cisgenesis and transgenesis are plant breeding techniques that can be used to introduce new genes into plant genomes. However, transgenesis uses gene(s from a non-plant organism or from a donor plant that is sexually incompatible with the recipient plant while cisgenesis involves the introduction of gene(s from a crossable--sexually compatible--plant. Traditional breeding techniques could possibly achieve the same results as those from cisgenesis, but would require a much larger timeframe. Cisgenesis allows plant breeders to enhance an existing cultivar more quickly and with little to no genetic drag. The current regulation in the European Union (EU on genetically modified organisms (GMOs treats cisgenic plants the same as transgenic plants and both are mandatorily labeled as GMOs. This study estimates European consumers' willingness-to-pay (WTP for rice labeled as GM, cisgenic, with environmental benefits (which cisgenesis could provide, or any combination of these three attributes. Data were collected from 3,002 participants through an online survey administered in Belgium, France, the Netherlands, Spain and the United Kingdom in 2013. Censored regression models were used to model consumers' WTP in each country. Model estimates highlight significant differences in WTP across countries. In all five countries, consumers are willing-to-pay a premium to avoid purchasing rice labeled as GM. In all countries except Spain, consumers have a significantly higher WTP to avoid consuming rice labeled as GM compared to rice labeled as cisgenic, suggesting that inserting genes from the plant's own gene pool is more acceptable to consumers. Additionally, French consumers are willing-to-pay a premium for rice labeled as having environmental benefits compared to conventional rice. These findings suggest that not all GMOs are the same in consumers' eyes and thus, from a consumer preference perspective, the differences between transgenic and cisgenic

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)

Breeding for earliness, high yield and disease resistance in rice by means of induced mutations

Energy Technology Data Exchange (ETDEWEB)

Haq, M S; Ali, S M; Maniruzzaman, A F.M.; Mansur, A; Islam, R [Atomic Energy Centre, Dacca (Pakistan)

1970-03-01

Ten varieties of Boro, Aus and Aman rice were treated with 30 kR of gamma rays from the 500-Ci {sup 60}Co source of the Atomic Energy Centre of Dacca. In addition, two rice varieties were treated with EMS and dES. To suppress tillering, the seeds were sown late and at a high seed rate. 300 normal-looking fertile M{sub 1} plants from each variety were harvested at random. The M{sub 2} progenies were sown on a plant-to-row basis to select for high yield, earliness, blast resistance and response to large doses of nitrogen fertilizer. Characters like plant height, number of tillers, fertile tillers, length of panicle and time from sowing to maturity were checked. As the results showed great variability in the mutagen-treated material the chances for successful selection are promising. (author)

Sort of agricultural species introducing in production resulting of mutation breeding programs in cuba

International Nuclear Information System (INIS)

Perez Talavera, Susana

1999-01-01

Radiomutant varieties of important species used in the Cuban agricultural productions are shown. They were obtained by INIFAT specialists as authors or co-author with the aid of radiomutation techniques in plant breeding programs. Several dates concerning the procedure and some of the features rendering varieties more useful are given. The introduction and acceptability by farmers are also commented. The information was collected from members of the scientific staff involving in the results and from the available literature

Screening of IR50 x Rathu Heenati F7 RILs and identification of SSR markers linked to brown planthopper (Nilaparvata lugens Stål) resistance in rice (Oryza sativa L.).

Science.gov (United States)

Kumari, Sanju; M Sheba, Jennifer; Marappan, Maheshwaran; Ponnuswamy, Shanmugasunderam; Seetharaman, Suresh; Pothi, Nagarajan; Subbarayalu, Mohankumar; Muthurajan, Raveendran; Natesan, Senthil

2010-09-01

Brown planthopper (Nilaparvata lugens Stål) is one of the major insect pests of rice. A Sri Lankan indica rice cultivar Rathu Heenati was found to be resistant to all biotypes of the brown planthopper. In the present study, a total of 268 F(7) RILs of IR50 and Rathu Heenati were phenotyped for their level of resistance against BPH by the standard seedbox screening test (SSST) in the greenhouse. A total of 53 SSR primers mapped on the chromosome 3 were used to screen the polymorphism between the parents IR50 and Rathu Heenati, out of which eleven were found to be polymorphic between IR50 and Rathu Heenati. The eleven primers that have shown polymorphism between the IR50 and Rathu Heenati parents were genotyped in a set of five resistant RILs and five susceptible RILs along with the parents for co-segregation analysis. Among the eleven primers, two primers namely RM3180 (18.22 Mb) and RM2453 (20.19 Mb) showed complete co-segregation with resistance. The identification of SSR markers linked with BPH resistant could be used for the maker assisted selection (MAS) program in rice breeding and to map the resistant genes on rice chromosomes for further gene cloning.

Genomic Tools in Pea Breeding Programs: Status and Perspectives

Science.gov (United States)

Tayeh, Nadim; Aubert, Grégoire; Pilet-Nayel, Marie-Laure; Lejeune-Hénaut, Isabelle; Warkentin, Thomas D.; Burstin, Judith

2015-01-01

Pea (Pisum sativum L.) is an annual cool-season legume and one of the oldest domesticated crops. Dry pea seeds contain 22–25% protein, complex starch and fiber constituents, and a rich array of vitamins, minerals, and phytochemicals which make them a valuable source for human consumption and livestock feed. Dry pea ranks third to common bean and chickpea as the most widely grown pulse in the world with more than 11 million tons produced in 2013. Pea breeding has achieved great success since the time of Mendel's experiments in the mid-1800s. However, several traits still require significant improvement for better yield stability in a larger growing area. Key breeding objectives in pea include improving biotic and abiotic stress resistance and enhancing yield components and seed quality. Taking advantage of the diversity present in the pea genepool, many mapping populations have been constructed in the last decades and efforts have been deployed to identify loci involved in the control of target traits and further introgress them into elite breeding materials. Pea now benefits from next-generation sequencing and high-throughput genotyping technologies that are paving the way for genome-wide association studies and genomic selection approaches. This review covers the significant development and deployment of genomic tools for pea breeding in recent years. Future prospects are discussed especially in light of current progress toward deciphering the pea genome. PMID:26640470

Genomic tools in pea breeding programs: status and perspectives

Directory of Open Access Journals (Sweden)

Nadim eTAYEH

2015-11-01

Full Text Available Pea (Pisum sativum L. is an annual cool-season legume and one of the oldest domesticated crops. Dry pea seeds contain 22-25 percent protein, complex starch and fibre constituents and a rich array of vitamins, minerals, and phytochemicals which make them a valuable source for human consumption and livestock feed. Dry pea ranks third to common bean and chickpea as the most widely grown pulse in the world with more than 11 million tonnes produced in 2013. Pea breeding has achieved great success since the time of Mendel’s experiments in the mid-1800s. However, several traits still require significant improvement for better yield stability in a larger growing area. Key breeding objectives in pea include improving biotic and abiotic stress resistance and enhancing yield components and seed quality. Taking advantage of the diversity present in the pea genepool, many mapping populations have been constructed in the last decades and efforts have been deployed to identify loci involved in the control of target traits and further introgress them into elite breeding materials. Pea now benefits from next-generation sequencing and high-throughput genotyping technologies that are paving the way for genome-wide association studies and genomic selection approaches. This review covers the significant development and deployment of genomic tools for pea breeding in recent years. Future prospects are discussed especially in light of current progress towards deciphering the pea genome.

Breeding, genetic and genomic of citrus for disease resistance

Directory of Open Access Journals (Sweden)

Marcos A. Machado

2011-10-01

Full Text Available Although the citriculture is one of the most important economic activities in Brazil, it is based on a small number of varieties. This fact has contributed for the vulnerability of the culture regarding the phytosanitary problems. A higher number of varieties/genotypes with potential for commercial growing, either for the industry or fresh market, has been one of the main objectives of citrus breeding programs. The genetic breeding of citrus has improved, in the last decades, due to the possibility of an association between biotechnological tools and classical methods of breeding. The use of molecular markers for early selection of zygotic seedlings from controlled crosses resulted in the possibility of selection of a high number of new combination and, as a consequence, the establishment of a great number of hybrids in field experiments. The faster new tools are incorporated in the program, the faster is possibility to reach new genotypes that can be tested as a new variety. Good traits should be kept or incorporate, whereas bad traits have to be excluded or minimized in the new genotype. Scion and rootstock can not be considered separately, and graft compatibility, fruit quality and productivity are essential traits to be evaluated in the last stages of the program. The mapping of QTLs has favored breeding programs of several perennial species and in citrus it was possible to map several characteristics with qualitative and quantitative inheritance. The existence of linkage maps and QTLs already mapped, the development of EST and BAC library and the sequencing of the Citrus complete genome altogether make very demanding and urgent the exploration of such data to launch a wider genetic study of citrus. The rising of information on genome of several organisms has opened new approaches looking for integration between breeding, genetic and genome. Genome assisted selection (GAS involves more than gene or complete genome sequencing and is becoming

Estimation of genetic divergence in rice (oryza sativa l) germplasms on the basis of paddy yield and rice stem borer's (pyralidae: lepidoptera) resistance

International Nuclear Information System (INIS)

Sarwar, M.

2013-01-01

Field trials were carried out to estimate resistance along with paddy yield in 55 rice germplasm lines (35 aromatic and 20 non-aromatic genotypes) for rice stem borers (Pyralidae: Lepidoptera) to expose their potential in pest management approach. The results expressed significant differences for pest damage build-up and paddy yield among the rice germplasm lines. The findings clearly portrayed that based upon the percentage of pest invasions (dead hearts and white heads damage), no genotype was exclusively resistant to stem borers damage under field conditions. Two aromatic genotypes, Jajai-15A/97 and Basmati-Cr-34, exhibited least borers prevalence and amplified paddy yield while Sonehri Sugdasi (P) and Sada Gulab (P) pointed out a peak pest invasion and declined paddy yield. The estimation of pest incidence build-up and paddy productivity within non-aromatic genotypes confirmed that IR8 (P), IR6-15-2 and IR6 (P) were mainly proficient for bearing condensed pest invasion and augmented paddy yield. IR8-2.5-4, IR6-15-10 and IR6-20-9 demonstrated elevated pest susceptibility and gave poor yield. Rest of the germplasms appeared to be least tolerant or vulnerable to pest build-up and reduced paddy production. The tolerant and high yielding genotypes should be popularised in rice borers endemic areas and can be used in varietals resistance breeding strategy. The outcome of current studies necessitates the integration of existing host plant tolerance along with other management strategies to accomplish a suitable control of rice stem borers and enhance paddy yield. (author)

Report from the FAO/IAEA Plant Breeding and Genetics Section

Energy Technology Data Exchange (ETDEWEB)

NONE

1990-01-01

In 1989 we cared for 44 IAEA Technical Co-operation projects involving 35 developing countries and 64 different research institutions. Under the IAEA Research Contract Programme we had 70 active research contracts and 32 research agreements grouped into the following co-ordinated research programmes: use of induced mutations in connection with haploids and heterosis in cereals (1986-1991); improvement of rice and other cereals through mutation breeding in Latin America (1986-1991); use of induced mutation and in vitro culture techniques for improving crop plant resistance to diseases (1987-1992); mutation breeding of oil seed crops (1988-1993); improvement of root and tuber crops in tropical countries of Asia (1988-1993); in vitro mutation breeding of bananas and plantains (1988-1993); improvement of basic food crops in Africa through plant breeding, including the use of induced mutations (1989-1994). New research programmes cannot be started before 1991 when present ones are phasing out. The new research programmes could eventually deal with: domestication of new crop plants, improvement of industrial crops, the use of induced mutations to establish RFLP systems for genetic mapping and for mutant selection, the use of RFLP techniques for identification of induced genetic variation in vegetatively propagated plants and in vitro cultures, the control of plant virus diseases with the help of nuclear techniques. Project proposals on these topics are welcome, although their approval will depend upon the availability of funds. Six research co-ordination meetings were held in 1989 in Thailand (2), India, Austria, Chile and Italy. The Section was also actively involved in the 12th EUCARPIA Congress 'Science for Plant Breeding' (Goettingen, FRG, 27 February - 3 March) and in the 6th Congress of SABRAO 'Breeding Research: The Key to the Survival of the Earth' (Tsukuba, Japan, 21-25 August)

Genomic prediction in early selection stages using multi-year data in a hybrid rye breeding program.

Science.gov (United States)

Bernal-Vasquez, Angela-Maria; Gordillo, Andres; Schmidt, Malthe; Piepho, Hans-Peter

2017-05-31

The use of multiple genetic backgrounds across years is appealing for genomic prediction (GP) because past years' data provide valuable information on marker effects. Nonetheless, single-year GP models are less complex and computationally less demanding than multi-year GP models. In devising a suitable analysis strategy for multi-year data, we may exploit the fact that even if there is no replication of genotypes across years, there is plenty of replication at the level of marker loci. Our principal aim was to evaluate different GP approaches to simultaneously model genotype-by-year (GY) effects and breeding values using multi-year data in terms of predictive ability. The models were evaluated under different scenarios reflecting common practice in plant breeding programs, such as different degrees of relatedness between training and validation sets, and using a selected fraction of genotypes in the training set. We used empirical grain yield data of a rye hybrid breeding program. A detailed description of the prediction approaches highlighting the use of kinship for modeling GY is presented. Using the kinship to model GY was advantageous in particular for datasets disconnected across years. On average, predictive abilities were 5% higher for models using kinship to model GY over models without kinship. We confirmed that using data from multiple selection stages provides valuable GY information and helps increasing predictive ability. This increase is on average 30% higher when the predicted genotypes are closely related with the genotypes in the training set. A selection of top-yielding genotypes together with the use of kinship to model GY improves the predictive ability in datasets composed of single years of several selection cycles. Our results clearly demonstrate that the use of multi-year data and appropriate modeling is beneficial for GP because it allows dissecting GY effects from genomic estimated breeding values. The model choice, as well as ensuring

Seasonal and Topographical Factors Affecting Breeding Sites of Culex Larvae in Nakhon Si Thammarat, Thailand

OpenAIRE

Warabhorn PREECHAPORN; Mullica JAROENSUTASINEE; Krisanadej JAROENSUTASINEE; Jirawat SAETON

2007-01-01

This study investigated how the seasons affect the key breeding sites of Culex larvae in three topographical areas: mangrove, rice paddy and mountainous areas. We examined how the number of Culex larvae varied in different types of water containers. Water containers were categorised into the following groups: indoor/outdoor containers, artificial/natural containers, earthen/plastic containers, containers with/without lids and dark/light coloured containers. Samples were collected from 300 hou...

Assessment and genetic analysis of heavy metal content in rice grain using an Oryza sativa × O. rufipogon backcross inbred line population.

Science.gov (United States)

Huang, De-Run; Fan, Ye-Yang; Hu, Biao-Lin; Xiao, Ye-Qing; Chen, Da-Zhou; Zhuang, Jie-Yun

2018-03-01

Heavy metal accumulation in rice is a growing concern for public health. Backcross inbred lines derived from an interspecific cross of Oryza sativa × O. rufipogon were grown in two distinct ecological locations (Hangzhou and Lingshui, China). The objective of this study was to characterise the contents of heavy metal in rice grains, and to identify quantitative trait loci (QTLs) for heavy metal contents. The contents of Ni, As, Pb, Cr and Hg in milled rice showed a significant decline as compared with those in brown rice, whereas the content of Cd showed little change. The concentration of heavy metal in rice grain varied greatly between the two environments. A total of 24 QTLs responsible for heavy metal contents were detected, including two for both the brown and milled rice, 13 for brown rice only, and nine for milled rice only. All the QTLs except two had the enhancing alleles derived from O. rufipogon. Sixteen QTLs were clustered in six chromosomal regions. Environmental variation plays an important role in the heavy metal contents in rice grain. QTLs detected in this study might be useful for breeding rice varieties with low heavy metal content. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Mutation breeding newsletter. No. 20

Energy Technology Data Exchange (ETDEWEB)

NONE

1982-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 17

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-03-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 16

Energy Technology Data Exchange (ETDEWEB)

NONE

1980-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 8

Energy Technology Data Exchange (ETDEWEB)

NONE

1976-09-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 12

Energy Technology Data Exchange (ETDEWEB)

NONE

1978-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 10

Energy Technology Data Exchange (ETDEWEB)

NONE

1977-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 32

Energy Technology Data Exchange (ETDEWEB)

NONE

1988-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 18

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-07-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

Mutation breeding newsletter. No. 9

Energy Technology Data Exchange (ETDEWEB)

NONE

1977-01-01

This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.