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Sample records for cotton root rot

  1. Molecular systematics of the cotton root rot pathogen, Phymatotrichopsis omnivora

    NARCIS (Netherlands)

    Marek, S.M.; Hansen, K.; Romanish, M.; Thorn, R.G.

    2009-01-01

    Cotton root rot is an important soilborne disease of cotton and numerous dicot plants in the south-western United States and Mexico. The causal organism, Phymatotrichopsis omnivora (= Phymatotrichum omnivorum), is known only as an asexual, holoanamorphic (mitosporic) fungus, and produces conidia

  2. Molecular systematics of the cotton root rot pathogen, Phymatotrichopsis omnivora

    NARCIS (Netherlands)

    Marek, S.M.; Hansen, K.; Romanish, M.; Thorn, R.G.

    2009-01-01

    Cotton root rot is an important soilborne disease of cotton and numerous dicot plants in the south-western United States and Mexico. The causal organism, Phymatotrichopsis omnivora (= Phymatotrichum omnivorum), is known only as an asexual, holoanamorphic (mitosporic) fungus, and produces conidia res

  3. Combining fuzzy set theory and nonlinear stretching enhancement for unsupervised classification of cotton root rot

    Science.gov (United States)

    Cotton root rot is a destructive disease affecting cotton production. Accurate identification of infected areas within fields is useful for cost-effective control of the disease. The uncertainties caused by various infection stages and newly infected plants make it difficult to achieve accurate clas...

  4. Controlled release fungicide, soil amendments and biofumigation effects on cotton root rot suppression

    Science.gov (United States)

    The cotton root rot pathogen (Phymatotrichopsis ominora) causes major losses in cotton produced in the Southwest. Granular controlled release formulations (CRF) of the fungicide, Propiconazole, developed to be soil applied at planting were studied at 1.0 and 3.0 lb a.i./ac. applications and with tw...

  5. Disease notes - Bacterial root rot

    Science.gov (United States)

    Bacterial root rot initiated by lactic acid bacteria, particularly Leuconostoc, occurs every year in Idaho sugarbeet fields. Hot fall weather seems to make the problem worse. Although Leuconostoc initiates the rot, other bacteria and yeast frequently invade the tissue as well. The acetic acid bac...

  6. Root rot in sugar beet piles at harvest

    Science.gov (United States)

    Sugar beet root rots are not only a concern because of reduced yields, but can also be associated with losses in storage. Our primary sugar beet root rot disease problem in the Amalgamated production area is Rhizoctonia root rot. However, this rot frequently only penetrates a short distance past t...

  7. Sugarbeet root rot in drought conditions

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    Jasnić Stevan M.

    2005-01-01

    Full Text Available In recent years several types of sugarbeet root rot have occurred in our country causing significant economic damage. The most frequent symptoms are leaf chlorosis and brown-black wet necrosis of the root. The necrosis spread through the entire root and vascular strands. In the course of this study F. oxysporum was the most frequently isolated from infected sugar beet roots. The incidence of other fungi (Fusarium solani, Rhizoctonia solani and Macrophomina phaseolina was much lower and it depended on weather conditions. High temperatures occurring during dry years encourage the development of F. oxysporum, the causer of sugar beet root rot. In 2000, an extremely dry year, plant vitality was satisfactory in the experiment with irrigation and the average root rot incidence was low (2,91%. In the nonirrigated variant the average incidence was high (71,02%. It may be concluded on the basis of the results from five years (2000-2004 that the major causal agents of sugarbeet root rot in our country are species from genus Fusarium, especially F. oxysporum. Fusarium wilt and root rot are due to the increased frequency of dry and warm years.

  8. Detecting cotton boll rot with an electronic nose

    Science.gov (United States)

    South Carolina Boll Rot is an emerging disease of cotton, Gossypium hirsutum L., caused by the opportunistic bacteria, Pantoea agglomerans (Ewing and Fife). Unlike typical fungal diseases, bolls infected with P. agglomerans continue to appear normal externally, complicating early and rapid detectio...

  9. Etiology of phomopsis root rot in soybean

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    Valéria Cecília Ghissi

    2014-09-01

    Full Text Available In a survey of damages caused by soybean root rot to crops in the south of Brazil for several years, a root rot caused by Phomopsis sp has been found with increasing frequency. The primary symptoms are seen when the main root is cut longitudinally, including the death of the wood which shows white coloration and well-defined black lines that do not have a defined format. Thus, based on similarity, it has been called geographic root rot due to its aspect resembling irregular lines that separate regions on a map. In isolations, colonies and alpha spores of Phomopsis have prevailed. Pathogenicity test was done by means of inoculation in the crown of plants cultivated in a growth chamber. The geographic symptoms were reproduced in plants and the fungus Phomopsis sp. was reisolated. In soybean stems naturally infected with pod and stem blight, geographic symptoms caused by Phomopsis phaseoli are found. To the known symptoms on stems, pods and grains, that of root rot caused by P. phaseoli is now added.

  10. Response of the Andean diversity panel to root rot in a root rot nursery in Puerto Rico

    Science.gov (United States)

    The Andean Diversity Panel (ADP) was evaluated under low-fertility and root rot conditions in two trials conducted in 2013 and 2015 in Isabela, Puerto Rico. About 246 ADP lines were evaluated in the root rot nursery with root rot and stem diseases caused predominantly by Fusarium solani, which cause...

  11. MANAGEMENT OF ROOT ROT IN AVOCADO TREES

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    SIMONE RODRIGUES DA SILVA

    Full Text Available ABSTRACT Root rot (Phytophthora cinnamomi Rands is one of the most restrictive factors to avocado growing in main producing regions worldwide. In Brazil, scientific reports on the effectiveness of control methods are scarce. The objective of this study was to evaluate the efficiency of gypsum applications and dolomitic limestone to the soil and potassium phosphite sprays in controlling this disease in ‘Hass’ avocado, grown without irrigation. The application of dolomitic limestone or gypsum alone is not effective to recover plants affected by root rot. The application of potassium phosphite, combined or not with dolomitic lime or gypsum enables the partial recovery ‘Hass’ avocado plants affected by the disease.

  12. A diagnostic guide for Fusarium Root Rot of pea

    Science.gov (United States)

    Fusarium root rot, caused by Fusarium solani f. sp. pisi, is a major root rot pathogen in pea production areas worldwide. Here we provide a diagnostic guide that describes: the taxonomy of the pathogen, signs and symptoms of the pathogen, host range, geographic distribution, methods used to isolate ...

  13. Root rot diseases of sugar beet

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    Jacobsen Barry J.

    2006-01-01

    Full Text Available Root rot diseases of sugar beet caused by Rhizoctonia solani (AG 2-2 IIIB and AG 2-2 IV, R. crocorum, Aphanomyces cochlioides, Phoma betae, Macrophomina phaeseolina, Fusarium oxysporum f.sp. radicis-betae, Pythium aphanidermatum Phytophthora drechsleri, Rhizopus stolonifer, R. arrhizus and Sclerotium rolfsii cause significant losses wherever sugar beets are grown. However, not all these soil-borne pathogens have been reported in all sugar beet production areas. Losses include reduced harvestable tonnage and reduced white sugar recovery. Many of these pathogens also cause post harvest losses in storage piles. Control for diseases caused by these pathogens include disease resistant cultivars, avoidance of stresses, cultural practices such as water management and the use of fungicides.

  14. Etiology and Epidemiological Conditions Promoting Fusarium Root Rot in Sweetpotato.

    Science.gov (United States)

    Scruggs, A C; Quesada-Ocampo, L M

    2016-08-01

    Sweetpotato production in the United States is limited by several postharvest diseases, and one of the most common is Fusarium root rot. Although Fusarium solani is believed to be the primary causal agent of disease, numerous other Fusarium spp. have been reported to infect sweetpotato. However, the diversity of Fusarium spp. infecting sweetpotato in North Carolina is unknown. In addition, the lack of labeled and effective fungicides for control of Fusarium root rot in sweetpotato creates the need for integrated strategies to control disease. Nonetheless, epidemiological factors that promote Fusarium root rot in sweetpotato remain unexplored. A survey of Fusarium spp. infecting sweetpotato in North Carolina identified six species contributing to disease, with F. solani as the primary causal agent. The effects of storage temperature (13, 18, 23, 29, and 35°C), relative humidity (80, 90, and 100%), and initial inoculum level (3-, 5-, and 7-mm-diameter mycelia plug) were examined for progression of Fusarium root rot caused by F. solani and F. proliferatum on 'Covington' sweetpotato. Fusarium root rot was significantly reduced (P Fusarium spp. revealed the production of fumonisin B1 by F. proliferatum when infecting sweetpotato. This study is a step toward characterizing the etiology and epidemiology of Fusarium root rot in sweetpotato, which allows for improved disease management recommendations to limit postharvest losses to this disease.

  15. SSR-based detection of genetic variability in the charcoal root rot pathogen Macrophomina phaseolina.

    Science.gov (United States)

    Jana, Tarakanta; Sharma, Tilak R; Singh, Nagendra K

    2005-01-01

    Macrophomina phaseolina, the causal agent of charcoal root or collar rot, is an important plant pathogen especially in soybean and cotton. Single primers of simple sequence repeats (SSR) or microsatellite markers have been used for the characterization of genetic variability of different populations of M. phaseolina obtained from soybean and cotton grown in India and the USA. Genetic similarity between isolates was calculated, and cluster analysis was used to generate a dendrogram showing relationships between isolates collected from the two hosts. Forty isolates could be clustered into three major groups corresponding to their hosts and geographical region. The wide distribution of microsatellites in M. phaseolina genome was assessed by agarose gel electrophoresis of the PCR products generated by direct amplification of inter SSR regions DNA. This is the first report of the use of microsatellite markers to characterize the charcoal root rot pathogen. The SSR fingerprints (0.25-3.5 kb) generated using DNA from different populations of M. phaseolina of two hosts indicated that these repeats are interspersed within the genome of this pathogen. The variability found within closely related isolates of M. phaseolina indicated that such microsatellites are useful in population studies and represents a step towards identification of potential isolate diagnostic markers specific to soybean and cotton.

  16. Root rot of sugarbeet in the Vojvodina Province

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    Stojšin Vera B.

    2006-01-01

    Full Text Available Large changes introduced in the sugar beet production technology in the Vojvodina Province over last 40 years resulted in changes in the etiology and harmfulness of different agents of sugar beet root diseases. Improvements in cultivation practices reduced the harmfulness of some diseases while increased the harmfulness of others. Some disease agents became obsolete, but others gained importance. New agents of root diseases were found. The most frequent damages, persisting over long periods of time were caused by seedling damping-off, Fusarium root rot, charcoal root rot, parasitic (Rhizomania and non-parasitic root bearding. The parasitic damping-off caused by several fungal species but most frequently by Phoma betae occurred at the time when multigerm seeds were used in combination with extensive cultural practices. The agents of seedling diseases completely lost their significance as the consequence of switching to fungicide - treated monogerm seeds, earlier planting and improved soil tillage. In the period of intensive use of agricultural chemicals, seedling damping-off occurred frequently due to the phytotoxic action of chemicals (insecticides, herbicides and mineral fertilizers. In some years, frosts caused damping- off of sugar beet seedlings on a large scale in the Vojvodina Province. Poor sugar beet germination and emergence were frequently due to spring droughts. Sometimes they were due to strong winds. The occurrence of Fusarium root rot and charcoal root rot intensified on poor soils. Fusariosis symptoms were exhibited as plant wilting and different forms of root rot. In recent years root tip rot has occurred frequently in the first part of the growing season causing necrosis and dying of plants. Lateral roots tended to proliferate from the healthy tissue, giving the root a bearded appearance similar to Rhizomania. Fusarium oxysporum was the most frequent agent of this fusariosis. F. graminearum, F. equiseti, F. solani have also been

  17. Phytophthora root rot resistance in soybean E00003

    Science.gov (United States)

    Phytophthora root rot (PRR), caused by the oomycete Phytophthora sojae, is a devastating disease in soybean production. Using resistant cultivars has been suggested as the best solution for disease management. Michigan elite soybean E00003 is resistant to P. sojae and has been used as a PRR resist...

  18. Susceptibility of highbush blueberry cultivars to Phytophthora root rot

    Science.gov (United States)

    Phytophthora cinnamomi Rands is a ubiquitous soilborne pathogen associated with root rot in many woody perennial plant species, including highbush blueberry (Vaccinium sp.). To identify genotypes with resistance to the pathogen, cultivars and advanced selections of highbush blueberry were grown in a...

  19. Effects of nematicides on cotton root mycobiota.

    Science.gov (United States)

    Baird, R E; Carling, D E; Watson, C E; Scruggs, M L; Hightower, P

    2004-02-01

    Baseline information on the diversity and population densities of fungi collected from soil debris and cotton (Gossypium hirsutum L.) roots was determined. Samples were collected from Tifton, GA, and Starkville, MS containing cotton field soil treated with the nematicides 1,3-dichloroproprene (fumigant) and aldicarb (granules). A total of 10,550 and 13,450 fungal isolates were collected from these two study sites, respectively. Of this total, 34 genera of plant pathogenic or saprophytic species were identified. Pathogenic root fungi included Fusarium spp. (40% of all isolations), Macrophomina, Pythium, Rhizoctonia, and Sclerotium. Fusarium and Rhizoctonia were the most common fungal species identified and included F. oxysporum, F. verticillioides and F. solani, the three Fusarium species pathogenic on cotton plants. Population densities of Fusarium were not significantly different among locations or tissue types sampled. Macrophomina was isolated at greater numbers near the end of the growing seasons. Anastomosis groups of R. solani isolated from roots and soil debris included AG-3, -4, -7, 2-2, and -13 and anastomosis groups of binucleate Rhizoctonia included CAG-2, -3, and -5. Occurrences and frequency of isolations among sampling dates were not consistent. Fluctuations in the frequency of isolation of Rhizoctonia did not correspond with changes in frequency of isolation of the biological control fungus, Trichoderma. When individual or pooled frequencies of the mycobiota were compared to nematicide treatments, no specific trends occurred between treatments, application methods or rates. Results from this study show that use of 1,3-D and aldicarb in cotton fields does not significantly impact plant pathogenic fungi or saprophytic fungal populations. Thus cotton producers need not adjust seedling disease control measures when these two nematicides are used.

  20. Identification of soil-borne pathogens in a common bean root rot nursery in Isabela, Puerto Rico

    Science.gov (United States)

    Limited research has been completed on the root rot complex of the common bean (Phaseolus vulgaris L.) in the Caribbean, while yield losses of over 50% due to root rot disease have been reported worldwide. In this study, the predominant root rot pathogens in a 40-year old common bean root rot nurser...

  1. The occurrence of root rot and crown rot of rice in Gilan and Zanjan provinces, Iran.

    Science.gov (United States)

    Saremi, H; Okhovat, S M

    2004-01-01

    Root rot and crown rot of rice is one of the important fungal diseases of rice in Gilan and Zanjan provinces, Iran. During 1999--2002, samples of plant and soil around the roots of infected rice plants were collected and used to identify the causal agent. Root and crown parts were surface sterilized with sodium hypochlorite and then cultured on PDA (potato dextrose agar), PPA (pepton pentacholoritobenzene agar) and CLA (carnation leaf agar) media. Soil samples prepared in water agar were used to isolate the pathogen. The causal agent was identified as Fusarium moniliforme. Colonies were initially white but turned violet to grey late. Microconidia were arranged in chain and macroconidia were cylindrical and long with 3-5 septa. The disease was severe in Zanjan province particularly along Ghezel Ozan river where the infection ranged from 70-80%. Root and crown rot was more prevalent in areas where Champa and Gerdeh were being cultivated continuously. On the other hand, Sadri cultivars had relatively less infection. Persistent cultivation of rice and seed sowing method intensified disease development and caused significant economic losses.

  2. An integrated control of Pythium root rot of greenhouse tomato.

    Science.gov (United States)

    Tu, J C

    2002-01-01

    Pythium root rot caused by Pythium aphanidermatum is one of the most important diseases of greenhouse tomatoes. Hydroponic culture exacerbates the problem. Both nutrient film technique (NFT) and recirculating growing systems pose a challenge in the control of this disease, because the pathogen, especially the zoospores, can spread easily in the recirculating solution to the whole growing system. Fortunately, hydroponically grown plants are easier to manipulate than soil grown plants, proper manipulation of root environments can lead to excellent disease control. This paper reports the development of an effective integrated control measure for pythium root rot of tomato by integrating pH, bioagent, and ultra-violet irradiation in a specific manner. This integrated control consists of three operations: a) before transplanting, the UV system is connected to sterilize the recirculating solution using 100 mJcm-2; b) after transplanting, the nutrient solution is delivered at pH 5.0 regime for five weeks followed by adjusting pH to 5.8 to 6.2 regime for one week; and c) bacterial bioagent, such as Pseudomonas is introduced into the root zone at 100 mL per plant at 10(8) bacteria mL-1 or added to the nutrient solution to arrive at 10(6) bacteria mL-1 in the solution. This report also discusses the advantages and limitations of this measure in the control of pythium root rot.

  3. Survival of southern highbush blueberry cultivars in Phytophthora Root Rot Infested fields in South Mississippi

    Science.gov (United States)

    Phytophthora root rot is an important disease of commercial blueberries and is most severe when blueberries are grown in wet soils with poor drainage. Symptoms of Phytophthora root rot include small, yellow or red leaves, lack of new growth, root necrosis, and a smaller root system than healthy plan...

  4. Trichoderma spp. decrease Fusarium root rot in common bean

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    Hudson Teixeira

    2012-12-01

    Full Text Available The effectiveness of six Trichoderma-based commercial products (TCP in controlling Fusarium root rot (FRR in common bean was assessed under field conditions. Three TCP, used for seed treatment or applied in the furrow, increased seedling emergence as much as the fungicide fludioxonil. FRR incidence was not affected, but all TCP and fludioxonil reduced the disease severity, compared to control. Application of Trichoderma-based products was as effective as that of fludioxonil in FRR management.

  5. Resistance to Fusarium dry root rot disease in cassava accessions

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    Saulo Alves Santos de Oliveira

    2013-10-01

    Full Text Available The objective of this work was to identify sources of resistance to dry root rot induced by Fusarium sp. in cassava accessions. A macroconidial suspension (20 µL of 11 Fusarium sp. isolates was inoculated in cassava roots, from 353 acessions plus seven commercial varieties. Ten days after inoculation, the total area colonized by the pathogen on the root pulp was evaluated by digital image analysis. Cluster analysis revealed the presence of five groups regarding resistance. The root lesion areas ranged from 18.28 to 1,096.07 mm² for the accessions BGM 1518 and BGM 556, respectively. The genotypes BGM 1042, BGM 1552, BGM 1586, BGM 1598, and BGM 1692 present the best agronomical traits.

  6. Mapping Fusarium solani and Aphanomyces euteiches root rot resistance and root architecture quantitative trait loci in common bean (Phaseolus vulgaris)

    Science.gov (United States)

    Root rot diseases of bean (Phaseolus vulgaris L.) are a constraint to dry and snap bean production. We developed the RR138 RIL mapping population from the cross of OSU5446, a susceptible line that meets current snap bean processing industry standards, and RR6950, a root rot resistant dry bean in th...

  7. Efficacy of management tools for control of Pythium root rot of Douglas fir seedlings, 2010

    Science.gov (United States)

    This study investigated the efficacy of management tools for control of Pythium root rot of Douglas fir seedlings. This effort was conducted as part of the IR-4 Ornamental Horticulture program to evaluate fungicides and biopesticides for management of root, crown and stem rot of ornamental plants ca...

  8. Interaction of Rhizoctonia solani and Rhizopus stolonifer Causing Root Rot of Sugar Beet

    Science.gov (United States)

    In recent years, growers in Michigan and other sugar beet production areas of the United States have reported increasing incidence of root rot with little or no crown or foliar symptoms in sugar beet with Rhizoctonia crown and root rot. In addition, Rhizoctonia-resistant beets have been reported wit...

  9. Induce systemic resistance in lupine against root rot diseases.

    Science.gov (United States)

    Ali, Abeer A; Ghoneem, K M; El-Metwally, M A; Abd El-Hai, K M

    2009-02-01

    Root rot caused by soil borne pathogenic fungi is the most sever disease attacks lupine plants. Isolation trials from diseased plants in some areas of Dakahlia Province (Egypt) was carried out. Rhizoctonia solani and Fusarium solani proved to be the most dominant isolates. Meanwhile, Fusarium oxysporum and Sclerotium rolfsii were less frequent. Efficacies of some plant resistance elicitors viz.: chitosan (CHI), Salicylic Acid (SA) and hydroquinone (HQ) in comparing to the fungicide Rhizolex T-50 as seed treatments showed significant reduction in the fungal growth in vitro. Chitosan at 8 g L(-1) and fungicide completely inhibited the growth of all isolated fungi, while SA at 1.4 g L(-1) and HQ at 1.2 g L(-1) inhibited the growth of Fusarium solani and F. oxysporum, respectively. The greenhouse experiments showed that S. rolfesii (No. 6) and R. solani (No. 2) followed by F. solani (No. 5) and F. oxysporum (No. 9) were the most aggressive root rot fungi. Soaking susceptible lupine seeds (Giza 1) in each one of the three selected elicitors showed a significant reduction in seedlings mortality. CHI at 8 g L(-1) was superior in increasing the percentage of healthy plants to record 72.5, 80.9, 62.7and 64.3%, when seeds were grown in soil infested with of F. solani, F. oxysporum, R. solani and S. rolfesii, respectively. These results were confirmed under field conditions in two different locations i.e., Tag El-Ezz and El-Serow Research Stations. CHI 8 g L(-1) proved to be the best elicitor after fungicide, in reducing lupine root rot disease. It showed 41 and 60% reduction in the plants mortality comparing to 56.37 and 69.13% in case of Rhizolex-T in Tag El-Ezz and El-Serow locations, respectively. The treatments were accompanied with a significant increase in lupine growth parameters, yield components and physiological aspects. Application of CHI at 8 g L(-1) or HQ at 1.2 g L(-1) was the most potent in this respect as compared to check treatment.

  10. Rhizoctonia root rot (Rhizoctoni solani K ü h n of sugar beet in province Vojvodina

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    Stojšin Vera B.

    2006-01-01

    Full Text Available Sugar beet root rot appears regularly each year, but its intensity depends on agro ecological conditions. The predominant causers of root rot in Vojvodina are fungi from Fusarium genus and species Macrophomina phaseolina. Over the last couple of years, more intense occurrence of Rhizoctonia root rot has been observed. Rhizoctonia solani, the causal agent of root rot is present in sugar beet fields. During 2000-2005, on the territory of Vojvodina, the frequency of Rhizoctonia solani in phytopathological isolations from rotted sugar beet roots was between 0,0-18,2%. The intensity of the disease depends on localities, agro ecological conditions and genotypes. Symptoms of Rhizoctonia root rot were registered at some localities in all regions of Vojvodina: Srem, Banat and Bačka. The disease appearance is above all local. It occurs in small patches, on heavy, non-structured soil and on depressed wet parts of plots. Individual diseased plants can be found during July. Brown rot appears on sugar beet roots, with dried tissue on surface, which is present on the tail as well as on the middle part and the head of root. Tissues with described symptoms are deeper regarding the healthy part of root. On vertical root section, the necrotic changes are clearly visible comparing to tissue section without symptoms. The heavily infected tissue forms fissures on roots in most cases. Besides the above-mentioned symptoms on roots, the plant wilting and leaf handle necrosis as well as leaf dying are also observed. When rot spreads to the whole root head, plants quickly die.

  11. Root rot diseases of sugarbeet (Beta vulgaris L as affected by defloliation intensity

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    Karadimos Dimitros A.

    2006-01-01

    Full Text Available The aim of this work was to study the effect of sugar beet re-growth after water stress defoliation on root rots of three cultivars (Europa, Rival Corsica, which were spring sown in Thessaly, central Greece, for two growing seasons (2003-04. At the beginning of July, sugar beets were subjected to water deficit with irrigation withholding. A month later, three defoliation levels (control - C, moderate - MD, severe - SD and irrigation were applied. Thus, sugar beets were forced to re-grow and three harvests (15, 30 and 40 days after defoliation - DAD were conducted. Rotted roots per hectare were counted and pathogens were identified. Data were analyzed as a four-factor randomized complete block design with years, defoliation levels, sampling times and cultivars as main factors. The number of rotted roots was increased with the defoliation level and was significantly higher for SD sugar beets (3748 roots ha–1. No significant differences were found between C and MD treatments (1543 and 2116 roots ha–1, respectively. Rival was the most susceptible cultivar to root rots. Sugar beets were more susceptible to rotting 15 and 40 DAD (2778 and 2998 roots ha–1. The causal agents of root rots were the fungi, Fusarium spp., Rhizopus stolonifer, Macrophomina phaseolina and Rhizoctonia solani.

  12. Factors Influencing Development of Root Rot on Ginseng Caused by Cylindrocarpon destructans.

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    Rahman, Mahfuzur; Punja, Zamir K

    2005-12-01

    ABSTRACT The fungus Cylindrocarpon destructans (Zins) Scholten is the cause of root rot (disappearing root rot) in many ginseng production areas in Canada. A total of 80 isolates of C. destructans were recovered from diseased roots in a survey of ginseng gardens in British Columbia from 2002-2004. Among these isolates, 49% were classified as highly virulent (causing lesions on unwounded mature roots) and 51% were weakly virulent (causing lesions only on previously wounded roots). Pectinase and polyphenoloxidase enzymes were produced in vitro by C. destructans isolates when they were grown on pectin and phenol as a substrate, respectively. However, highly virulent isolates produced significantly (P disease development, ginseng roots were grown hydroponically in Hoagland's solution. Lesions were significantly larger (P disease by a highly virulent isolate at both pHs. In artificially infested soil, 2-year-old ginseng roots were most susceptible to Cylindrocarpon root rot among all root ages tested (1 to 4 years) when evaluated using a combined scale of disease incidence and severity. Root rot severity was significantly (P Disease severity was higher at 20 degrees C compared with 15 and 25 degrees C and at -0.02 MPa soil moisture compared with -0.005 and -0.001 MPa. A significant interaction between soil moisture and temperature was observed for root rot severity.

  13. [Nitrogen absorption and allocation in cotton plant under effects of double-cropping wheat and cotton root mass].

    Science.gov (United States)

    Wang, Ying; Zhou, Zhiguo; Chen, Binglin; Meng, Yali; Shu, Hongmei

    2006-12-01

    By the methods of 15N-foliar feeding and 15N dilution, a pot experiment of double-cropping wheat and cotton was conducted to study the nitrogen absorption and allocation in cotton plant under effects of wheat and cotton root mass. Three treatments were installed, i.e., no separation of wheat and cotton roots (treatment I), separation with nylon net (treatment II), and separation with plastic film (treatment III). The results showed that both the competition of 15N absorption between wheat and cotton root, and the translocation of absorbed 15N from wheat root to cotton were existed in the wheat-cotton double-cropping system. The absorbed 15N by cotton root was mostly allocated in aboveground part, and less in root. The aboveground part of cotton had the highest N utilization rate (NUR) in treatment I and the lowest one in treatment III, but the Ndff was lower in treatment I than in treatments II and III. At the early flowering stage of cotton when wheat was harvested and its straw was amended in situ, the absorbed nitrogen by cotton was mainly from the applied 15N, but not from the amended wheat straw. The allocation of absorbed 15N in different organs of cotton was quite different, being much higher in reproductive organs than in other organs. The biomass of cotton plant was also higher in treatment I than in treatments II and III.

  14. Interaction of Meloidogyne javanica and Macrophomina phaseoli in Kenaf Root Rot.

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    Tu, C C; Cheng, Y H

    1971-01-01

    Incidence and severity of root-rot caused by the fungus Macrophomina phaseoli was increased in screenhouse-grown kenaf (Hibiscus cannabinus L.) seedlings simultaneously infected by the nematode Meloidogyne javanica. In seedlings inoculated at 5, 10 and 15 days of age, root rot lesions increased 70.3, 44.1 and 21.8%, and nematode penetration increased 49.0, 36.7, and 12.3% when both fungus and nematode were present.

  15. Leuconostoc spp. Associated with Root Rot in Sugar Beet and Their Interaction with Rhizoctonia solani.

    Science.gov (United States)

    Strausbaugh, Carl A

    2016-05-01

    Rhizoctonia root and crown rot is an important disease problem in sugar beet caused by Rhizoctonia solani and also shown to be associated with Leuconostoc spp. Initial Leuconostoc studies were conducted with only a few isolates and the relationship of Leuconostoc with R. solani is poorly understood; therefore, a more thorough investigation was conducted. In total, 203 Leuconostoc isolates were collected from recently harvested sugar beet roots in southern Idaho and southeastern Oregon during 2010 and 2012: 88 and 85% Leuconostoc mesenteroides, 6 and 15% L. pseudomesenteroides, 2 and 0% L. kimchi, and 4 and 0% unrecognized Leuconostoc spp., respectively. Based on 16S ribosomal RNA sequencing, haplotype 11 (L. mesenteroides isolates) comprised 68 to 70% of the isolates in both years. In pathogenicity field studies with commercial sugar beet 'B-7', all Leuconostoc isolates caused more rot (P rot (P rot when both Leuconostoc spp. and R. solani are present in sugar beet roots.

  16. First Report of Root Rot of Cowpea Caused by Fusarium equiseti in Georgia in the United States

    Science.gov (United States)

    Root rot was observed on cowpea in Tift County, Georgia, in May of 2015. The disease occurred on approximately 10% of cowpea plants in 2 fields (2 ha). Symptoms appeared as sunken reddish brown lesions on roots and stems under the soil line, secondary roots became dark brown and rotted, and infected...

  17. Morphological and RAPD Analysis of Fusarium Species Associated with Root and Stem Rot of Dendrobium Orchid in Northern Peninsula Malaysia

    Directory of Open Access Journals (Sweden)

    LATIFFAH ZAKARIA

    2009-06-01

    Full Text Available A total of 29 Fusarium isolates were isolated from Dendrobium orchid showing symptoms of root and stem rots. Based on morphological characteristics, three species were identified namely, F. oxysporum, F. solani, and F. proliferatum which were recovered from root and stem rots of Dendrobium. Cluster analysis of RAPD bands clearly separated F. oxysporum, F. proliferatum, and F. solani into distinct clusters. The present studies showed that three Fusarium species were isolated from root and stem rot of Dendrobium and cluster analysis of RAPD bands was in agreement with morphological characterization of the Fusarium species from root and stem rot of Dendrobium.

  18. Survey of root rot diseases of sugar bett in Central Greece

    Directory of Open Access Journals (Sweden)

    Karadimos Dimitros A.

    2006-01-01

    Full Text Available An extensive survey was conducted during the summer and autumn of 2004 in sugar beet fields in the area of Larissa, Thessaly region, with plants showing symptoms of root rot diseases. The aim of the monitoring was to identify the causal agents of root rot diseases. In total, 76 sugar beet fields were surveyed and 5-10 diseased roots were examined from each field. Isolations, carried out on PDA, showed that two main fungal pathogens causing root rot were Rhizoctonia solani and Phytophthora cryptogea. The former was isolated in 46% of the fields and the latter in 38% of the fields. In addition, Rhizopus stolonifer, Fusarium spp., Scerotium rolfsii and Rhizoctonia violacea were isolated in 14%, 7%, 4% and 1% of the fields respectively. In most of the surveyed fields only one pathogen species was isolated and only in a few of them more than one fungal species was identified.

  19. Root rot symptoms in sugar beet lines caused by Fusarium oxysporum f. sp. betae

    Science.gov (United States)

    The soil-borne fungus Fusarium oxysporum may cause both Fusarium yellows and Fusarium root rot diseases with severe yield losses in cultivated sugar beet worldwide. These two diseases cause similar foliar symptoms but different root response and have been proposed to be due to two distinct F. oxyspo...

  20. Management of Phytophthora cinnamomi root rot disease of blueberry with gypsum and compost

    Science.gov (United States)

    Root rot disease of blueberry caused by Phytophthora cinnamomi is becoming more prevalent as a consequence of widespread adoption of drip irrigation. This creates higher moisture content in the root zone more conducive for the pathogen. Options for disease control under organic management are limi...

  1. A novel penicillium sp. causes rot in stored sugar beet roots in Idaho

    Science.gov (United States)

    Penicillium vulpinum along with a number of other fungi can lead to the rot of stored sugar beet roots. However, Penicillium isolates associated with necrotic lesions on roots from a recent sugar beet storage study were determined to be different from P. vulpinum and other recognized Penicillium sp...

  2. Root rot of peas in the Netherlands: fungal pathogens, inoculum potential and soil receptivity.

    NARCIS (Netherlands)

    Oyarzun, P.J.

    1994-01-01

    Fungi associated to pea (Pisum sativum L.) root rot were studied. Fusarium and Oomycetes were most common. Fusarium solani f. sp. pisi, Fsp, was widely distributed and the most frequent fungus in roots of diseased crops. The pathogens Thielaviopsis basicola , Tb, and Aphanomyces euteiches, Ae, wer

  3. Phytophthora Root and Crown Rot on Apples in Bulgaria

    Directory of Open Access Journals (Sweden)

    Mariana Nakova

    2010-01-01

    Full Text Available Phytophthora is a genus of Oomycota responsible for some of the most serious diseases with great economic impact (Judelson and Blanco, 2005. While 54 species were found in the 20th century (Erwin and Ribeiro, 1996 another 51-54 new species have been identified(Brasier, 2008 since the year 2000. They are spread worldwide and have broad range of host plants – fruit trees, citrus, forest and park species. Phytophthora can cause serious damages in orchards and nurseries of apples, cherries, etc. In Bulgaria they have been found first on young apples and cherries (1998-1999 in Plovdiv region (Nakova, 2003. Surveys have been done for discovering disease symptoms in Plovdiv and Kjustendil regions. Isolates have been obtained from infected plant material (roots and stem bases applying baiting bioassay (green apples, variety Granny Smith and/or PARP 10 selective media. Phytophthora strains were identified based on standard morphology methods – types of colonies on PDA, CMA, V 8, type and size of sporangia, oogonia and antheridia, andoospores. Cardial temperatures for their growth were tested on CMA and PDA.For molecular studies, DNA was extracted from mycelium using the DNA extraction kit.DNA was amplified using universal primers ITS 6 and ITS 4. Amplification products concentrations were estimated by comparison with the standard DNA. Sequencing was done at the Scottish Crop Research Institute (SCRI, Dundee, Scotland. Phytophthora root and crown rot symptoms first appear in early spring. Infected trees show bud break delay, have small chlorotic leaves, and branches die all of a sudden. Later symptoms are found in August-September. Leaves of the infected trees show reddish discoloration and drop down. Both symptoms are connected with lesions (wet, necrotic in appearance at stem bases of the trees.Disease spread was 2-3% in most gardens, only in an apple orchard in Bjaga (Plovdiv region it was up to 8-10%. Morphologically, the isolates acquired from

  4. Occurrence of Root Rot and Vascular Wilt Diseases in Roselle (Hibiscus sabdariffa L.) in Upper Egypt.

    Science.gov (United States)

    Hassan, Naglaa; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-03-01

    Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. The main objective of the present study is to identify and characterize pathogens associated with root rot and wilt symptoms of roselle in Qena, Upper Egypt and evaluate their pathogenicity under greenhouse and field condition. Fusarium oxysporum, Macrophomina phaseolina, Fusarium solani, Fusarium equiseti and Fusarium semitectum were isolated from the natural root rot diseases in roselle. All isolated fungi were morphologically characterized and varied in their pathogenic potentialities. They could attack roselle plants causing damping-off and root rot/wilt diseases in different pathogenicity tests. The highest pathogenicity was caused by F. oxysporum and M. phaseolina followed by F. solani. The least pathogenic fungi were F. equiseti followed by F. semitectum. It obviously noted that Baladi roselle cultivar was more susceptible to infection with all tested fungi than Sobhia 17 under greenhouse and field conditions. This is the first report of fungal pathogens causing root rot and vascular wilt in roselle in Upper Egypt.

  5. Nematicides and nonconventional soil amendments in the management of root-knot nematode on cotton.

    Science.gov (United States)

    Jorgenson, E C

    1984-04-01

    Granular and liquid commercial humates, with micronutrients, and a microbial fermentation product were compared in several combinations with nematicides for their effects on cotton lint yield and root-knot nematode suppression. Fumigant nematicides effectively reduced cotton root galling caused by root-knot nematodes, and cotton lint yields increased. Organophosphates and carbamates were not effective. Occasionally, cotton lint yields were increased or maintained with combination treatments o f humates, micronutrients, and a microbial fermentation product, but galling o f cotton roots by root-knot nematodes was usually not reduced by these treatments.

  6. Efficacy of Cotton Root Destruction and Winter Cover Crops for Suppression of Hoplolaimus columbus.

    Science.gov (United States)

    Davis, R F; Baird, R E; McNeil, R D

    2000-12-01

    The efficacy of rye (Secale cereale) and wheat (Triticum aestivum) winter cover crops and cotton stalk and root destruction (i.e., pulling them up) were evaluated in field tests during two growing seasons for Hoplolaimus columbus management in cotton. The effect of removing debris from the field following root destruction also was evaluated. Wheat and rye produced similar amounts of biomass, and both crops produced more biomass (P Cover crops did not suppress H. columbus population levels or increase subsequent cotton yields. Cotton root destruction did not affect cotton stand or plant height the following year. Cotton root destruction lowered (P cover crop or cotton root destruction following harvest is ineffective for H. columbus management in cotton.

  7. rDNA-based characterization of a new binucleate Rhizoctonia spp. causing root rot on kale in Brazil

    NARCIS (Netherlands)

    Kuramae, E.E.; Buzeto, A.L.; Nakatani, A.K.; Souza, N.L.

    2007-01-01

    In this paper we present the first report of the occurrence of a binucleate Rhizoctonia spp. causing hypocotyl and root rot in kale in Brazil. Rhizoctonia spp. were isolated from kale (Brassica oleracea var. acephala) with symptoms of hypocotyl and root rot. The isolates, characterized as binucleate

  8. rDNA-based characterization of a new binucleate Rhizoctonia spp. causing root rot on kale in Brazil

    NARCIS (Netherlands)

    Kuramae, E.E.; Buzeto, A.L.; Nakatani, A.K.; Souza, N.L.

    2007-01-01

    In this paper we present the first report of the occurrence of a binucleate Rhizoctonia spp. causing hypocotyl and root rot in kale in Brazil. Rhizoctonia spp. were isolated from kale (Brassica oleracea var. acephala) with symptoms of hypocotyl and root rot. The isolates, characterized as binucleate

  9. Root Rot of Balloon Flower (Platycodon grandiflorum) Caused by Fusarium solani and Fusarium oxysporum.

    Science.gov (United States)

    Jeon, Chi Sung; Kim, Gyoung Hee; Son, Kyeong In; Hur, Jae-Seoun; Jeon, Kwon-Seok; Yoon, Jun-Hyuck; Koh, Young Jin

    2013-12-01

    Balloon flower (Platycodon grandiflorum) is a kind of mountain herbs whose roots have restorative properties and the cultivating acreage of balloon flower has been steadily increasing in Korea. More frequent rain and high amount of rainfalls as a result of climate changes predisposed balloon flower to the outbreaks of root rot at high-density cultivation area in recent years. Root crowns were usually discolored into brown to blackish brown at first and the infected plants showed slight wilting symptom at early infection stage. Severely infected roots were entirely rotted and whole plants eventually died at late infection stage. The overall disease severities of root rot of balloon flower were quite variable according to the surveyed fields in Jeonnam, Gyeongnam and Jeju Provinces, which ranged from 0.1% to 40%. The root rot occurred more severely at the paddy or clay soils than the sandy soils and their severities were much higher at lowland than upland in the same localty. The disease increased with aging of the balloon flower. The causal fungi were identified as Fusarium solani and F. oxysporum on the basis of their mycological characteristics. The optimum temperature ranges of their mycelial growths was found to be 24°C. The pathogenic characters of F. solani and F. oxysporum treated by artificial wounding inoculation on healthy roots of balloon flower revealed that F. solani was more virulent than F. oxysporum. This study identified the causal agents of root rot of balloon flower as Fusarium solani and F. oxysporum, probably for the first time.

  10. An opportunistic Pantoea sp. isolated from a cotton fleahopper that is capable of causing cotton (Gossypium hirsutum L.) bud rot

    Science.gov (United States)

    Pantoea ananatis (Serano) representatives are known to have a broad host range including both humans and plants. The cotton fleahopper (Pseudatomoscelis seriatus, Reuter) is a significant pest that causes cotton bud damage that may result in significant yield losses. In this study, cotton fleahopp...

  11. Bacillus seed and boll rot of cotton: Symptoms and transmission by Hemiptera

    Science.gov (United States)

    Bolls affected by seed rot and internal boll rot were sampled from various geographical areas over three years and examined for organisms capable of causing disease. After Pantoea species and Nematospora coryli, Bacillus species were one of the microorganisms often associated with seed and boll rot...

  12. Cylindrocarpon root rot: multi-gene analysis reveals novel species within the Ilyonectria radicicola species complex

    NARCIS (Netherlands)

    Cabral, A.; Groenewald, J.Z.; Rego, C.; Oliveira, H.; Crous, P.W.

    2012-01-01

    Ilyonectria radicicola and its Cylindrocarpon-like anamorph represent a species complex that is commonly associated with root rot disease symptoms on a range of hosts. During the course of this study, several species could be distinguished from I. radicicola sensu stricto based on morphological and

  13. Identification of markers associated with race-specific resistance to Aphanomyces root rot in alfalfa

    Science.gov (United States)

    Aphanomyces root rot, caused by Aphanomyces euteiches, is one of the most important diseases of alfalfa in the United States. Two races of the pathogen are recognized and although most cultivars are resistant to race 1, fewer have resistance to race 2, the predominant race in North America. Molecula...

  14. Efficacy of management tools for control of Pythium root rot of Douglas-fir seedlings, 2013

    Science.gov (United States)

    This study was conducted as part of the IR-4 Ornamental Horticulture program to evaluate fungicides and biopesticides for management of root, crown and stem rots of ornamental plants caused by Pythium species. Pythium species used in this study were P. vipa (isolate 09), P. dissotocum (isolate 41-08...

  15. Study of the influence of winter rye on soybean seedling and root rot diseases

    Science.gov (United States)

    Cover crops can enhance or suppress plant diseases, but little is known about the effect of cover crops on soybean diseases. In 2015, the effect of winter rye (Secale cereale L.) cover crop on soybean seedling and root rot was studied at two experimental sites, Boyd and ISUAG-USB, in Ames, IA. Both ...

  16. Rhizosphere ecology and phytoprotection in soils naturally suppressive to Thielaviopsis black root rot of tobacco.

    Science.gov (United States)

    Almario, Juliana; Muller, Daniel; Défago, Geneviève; Moënne-Loccoz, Yvan

    2014-07-01

    Soil suppressiveness to disease is an intriguing emerging property in agroecosystems, with important implications because it enables significant protection of susceptible plants from soil-borne pathogens. Unlike many soils where disease suppressiveness requires crop monoculture to establish, certain soils are naturally suppressive to disease, and this type of specific disease suppressiveness is maintained despite crop rotation. Soils naturally suppressive to Thielaviopsis basicola-mediated black root rot of tobacco and other crops occur in Morens region (Switzerland) and have been studied for over 30 years. In Morens, vermiculite-rich suppressive soils formed on morainic deposits while illite-rich conducive soils developed on sandstone, but suppressiveness is of microbial origin. Antagonistic pseudomonads play a role in black root rot suppressiveness, including Pseudomonas protegens (formerly P. fluorescens) CHA0, a major model strain for research. However, other types of rhizobacterial taxa may differ in prevalence between suppressive and conducive soils, suggesting that the microbial basis of black root rot suppressiveness could be far more complex than solely a Pseudomonas property. This first review on black root rot suppressive soils covers early findings on these soils, the significance of recent results, and compares them with other types of suppressive soils in terms of rhizosphere ecology and plant protection mechanisms.

  17. Cylindrocarpon root rot: multi-gene analysis reveals novel species within the Ilyonectria radicicola species complex

    NARCIS (Netherlands)

    Cabral, A.; Groenewald, J.Z.; Rego, C.; Oliveira, H.; Crous, P.W.

    2012-01-01

    Ilyonectria radicicola and its Cylindrocarpon-like anamorph represent a species complex that is commonly associated with root rot disease symptoms on a range of hosts. During the course of this study, several species could be distinguished from I. radicicola sensu stricto based on morphological and

  18. Identification and Characterization of Partial Resistance to Fusarium root rot in the Pisum Core Collection

    Science.gov (United States)

    Fusarium solani f. sp. pisi (Fsp) is a serious seed and root rot pathogen found in both dryland and irrigated peas in the USA. Resistance to Fsp in 44 wild pea accessions from the Pisum Core Collection located in Pullman, WA, USA was characterized under greenhouse conditions. Germination rates, ro...

  19. QTL analysis for Fusarium root rot resistance in snap bean under greenhouse conditions

    Science.gov (United States)

    Fusarium root rot (FRR), caused by Fusarium solani f. sp. phaseoli (syn.F. phaseoli T. Aoki & O’Donnell, F. cuneirostrum O’Donnell & T. Aoki), is considered as one of the most economically important and widespread fungal diseases of common bean (1). Progress in breeding for FRR resistance has been h...

  20. Evaluation of pea accessions and commercial cultivars for Fusarium Root Rot resistance

    Science.gov (United States)

    Fusarium root rot caused by Fusarium solani f. sp. pisi (Fsp) can result in major yield losses in pea (Pisum sativum L.). Currently no fungicides effectively manage this disease. Previous studies evaluated the Pisum germplasm collection for resistance to Fsp, however, evaluations of commercial marke...

  1. Mechanisms of qualitative and quantitative resistance to Aphanomyces root rot in alfalfa

    Science.gov (United States)

    Aphanomyces root rot (ARR), caused by Aphanomyces euteiches, is one of the most important diseases of alfalfa (Medicago sativa) in the United States. Two races of the pathogen are currently recognized. Most modern alfalfa cultivars have high levels of resistance to race 1 but few cultivars have resi...

  2. Irrigation affects severity of root rot caused by Phythophthora plurivora and P. cinnamomi on rhododendron

    Science.gov (United States)

    Plant pathogens in the genus Phytophthora cause root rot that decrease product quality and result in plant death and economic losses to the nursery industry. Recently, we found Phytophthora plurivora prevalent on rhododendron in nurseries in the Pacific Northwest, USA, but there is little informatio...

  3. Armillaria root rot of tea in Kenya. Characterization of the pathogen and approaches to disease management

    NARCIS (Netherlands)

    Otieno, W.

    2002-01-01

    The rare occurrence of basidiomata and rhizomorphs constrains diagnosis of Armillaria root rot and identification of Armillaria species in Africa. This has had a negative impact on taxonomic research on the genus Armillaria in the continent, where the existence of various genetic groups of the fungu

  4. Rhizoctonia root rot resistance in experimental sugar beet cultivars in Twin Falls County, ID, 2012

    Science.gov (United States)

    Rhizoctonia root rot continues to be a concerning problem in sugar beet production areas. To investigate resistance to this disease in 26 experimental sugar beet cultivars, field studies were conducted with three Rhizoctonia solani AG-2-2 IIIB strains. Based on means for the 26 cultivars, surface ...

  5. Rhizoctonia root rot resistance in commercial sugar beet cultivars in Twin Falls County, ID, 2012

    Science.gov (United States)

    Rhizoctonia root rot continues to be a concerning problem in sugar beet production areas. To investigate resistance to this disease in 26 commercial sugar beet cultivars, field studies were conducted with three Rhizoctonia solani AG-2-2 IIIB strains. Based on means for the 26 cultivars, surface ro...

  6. New record of Phytophthora root and stem rot of Lavandula angustifolia

    Directory of Open Access Journals (Sweden)

    Leszek B. Orlikowski

    2013-12-01

    Full Text Available Phytophthora cinnamomi was isolated from rotted root and stem parts of lavender as well as from soil taken from containers with diseased plants. Additionally Botrytis cinerea, Fusarium spp. and Sclerotinia sclerotiorum were often isolated from diseased tissues. P. cinnamomi colonised leaves and stem parts of 4 lavender species in laboratory trials and caused stem rot of plants in greenhouse experiments. Cardinal temperature for in vitro growth were about 7,5 and 32°C with optimum 25-27,5°C. The species colonised stem tissues at temperature ranged from 10° to 32°C.

  7. Phytophthora root and stem rot – new disease of Ilex aquifolium "Myrtifolia” in Poland

    Directory of Open Access Journals (Sweden)

    Leszek B. Orlikowski

    2014-08-01

    Full Text Available Phytophthora cinnamomi was often isolated from rotted roots and stems of English holly "Myrtifolia" together with Alternaria alternata, Cylindrocarpon destructanss, Fusarium avenaceum and other fungal species. Inoculation of leaf blades and stem parts of 4 species and 12 holly cultivars with P. cinnamomi showed the spread of rot symptoms on the most of them. On Ilex crenata tissues necrosis did not develop or spread slowly. Isolation of P. cinnamomi only from one holly cultivar in surveyed nursery indicate on transmission of the pathogen with imported young plants.

  8. Root exudates of transgenic cotton and their effects on Fusarium oxysporum.

    Science.gov (United States)

    Li, Xiao-gang; Wei, Qin; Liu, Biao; Alam, Mohammad-Saiful; Wang, Xing-xiang; Shen, Wenjing; Han, Zheng-min

    2013-01-01

    The components of the root exudates from two transgenic insect-resistant cotton lines and their parental cotton lines, and their effects on the growth of Fusarium oxysporum were investigated. The results demonstrated that the resistance of transgenic insect-resistant cotton to F. oxysporum was significantly reduced compared with their parental lines. Likewise, the root exudates from transgenic insect-resistant cotton significantly promoted the spore germination and mycelial growth of cotton F. oxysporum. The types of compounds found in the root exudates of transgenic insect-resistant cotton were similar to those of the parental cotton, but the composition and relative content of the compounds were different. The type and content of the fatty acids and esters were significantly reduced in the root exudates of the transgenic insect-resistant cotton, as were certain specific materials, whereas several alkanes were increased. The inhibition of the soil-borne pathogen F. oxysporum caused by the root exudates from the transgenic insect-resistant cotton was decreased compared with the parental cotton. This result provides a scientific basis for the decline in disease resistance in transgenic insect-resistant cotton.

  9. Phenotypic and molecular evaluation of cotton hairy roots as a model system for studying nematode resistance

    Science.gov (United States)

    The cellular mechanisms that mediate resistance of allotetraploid cotton (Gossypium spp.) to root-knot nematode (Meloidogyne incognita) and reniform nematode (Rotylenchulus reniformis) are poorly understood. Here, Agrobacterium rhizogenes-induced hairy roots were investigated as a possible research...

  10. Insights Into Triticum aestivum Seedling Root Rot Caused by Fusarium graminearum.

    Science.gov (United States)

    Wang, Qing; Vera Buxa, Stefanie; Furch, Alexandra; Friedt, Wolfgang; Gottwald, Sven

    2015-12-01

    Fusarium graminearum is one of the most common and potent fungal pathogens of wheat (Triticum aestivum), known for causing devastating spike infections and grain yield damage. F. graminearum is a typical soil-borne pathogen that builds up during consecutive cereal cropping. Speculation on systemic colonization of cereals by F. graminearum root infection have long existed but have not been proven. We have assessed the Fusarium root rot disease macroscopically in a diverse set of 12 wheat genotypes and microscopically in a comparative study of two genotypes with diverging responses. Here, we show a 'new' aspect of the F. graminearum life cycle, i.e., the head blight fungus uses a unique root-infection strategy with an initial stage typical for root pathogens and a later stage typical for spike infection. Root colonization negatively affects seedling development and leads to systemic plant invasion by tissue-adapted fungal strategies. Another major outcome is the identification of partial resistance to root rot. Disease severity assessments and histological examinations both demonstrated three distinct disease phases that, however, proceeded differently in resistant and susceptible genotypes. Soil-borne inoculum and root infection are considered significant components of the F. graminearum life cycle with important implications for the development of new strategies of resistance breeding and disease control.

  11. Synergistic Effects of Nanochitin on Inhibition of Tobacco Root Rot Disease.

    Science.gov (United States)

    Zhou, Yang; Jiang, Shijun; Jiao, Yongji; Wang, Hezhong

    2017-02-22

    Nanomaterials have great potential for use in various fields, due to their unique properties. In order to explore the bioactivity of nanochitin on tobacco, the effects of nanochitin suspensions on tobacco seed germination, seedling growth, and synergistic effects with fungicides were studied in indoor and field trials. Results showed that 0.004% (w/v) of nanochitin improved tobacco seed germination and shortened mean time to germination significantly; 0.005% (w/v) of nanochitin increased tobacco stem length, stem girth, leaf number and leaf area, and 0.001% (w/v) of nanochitin had synergistic effects on inhibition of tobacco root rot when mixed with metalaxyl mancozeb and thiophanate methyl fungicides. This indicates that nanochitin suspensions have a strong potential to protect tobacco from tobacco root rot diseases and reduce the use of chemical fungicides in tobacco plantations.

  12. The Use of Antioxidants to Control Root Rot and Wilt Diseases of Pepper

    Directory of Open Access Journals (Sweden)

    Montaser Fawzy ABDEL-MONAIM

    2010-06-01

    Full Text Available Ten isolates of Fusarium spp were isolated from pepper plants collected from different locations in New Valley Governorate, Egypt. Fusarium solani isolate FP2 and F. oxysporum isolate FP4 were highly pathogenic isolates but the other isolates moderate or less pathogenic to pepper plants (cv. Anaheim-M. The four antioxidant compounds (coumaric acid, citric acid, propylgalate and salicylic acid each at 100 and 200 ppm were evaluated for their in vitro and in vivo agonist to Fusarium pathogenic isolates caused root rot and wilt diseases in pepper plants. All tested antioxidant compounds reduced damping-off, root rot/wilt and area under root rot/wilt progress curve when used as seed soaking, seedling soaking, and soil drench especially at 200 ppm under greenhouse and field conditions compared with untreated plants. All chemicals increased fresh and dry weight of seedling grown in soil drenching or seed treatment with any antioxidants. At the same time, all tested chemicals significantly increase plant growth parameters i.e plant length, plant branching, and total yield per plant in case of seedling soaking or soil drench. In general, propylgalate at 200 ppm was more efficient in reducing infection with damping-off, root rot and wilt diseases as well as increasing the seedling fresh weight, dry weight, plant length, plant branching, number of pod plant-1 and pod yield plant-1. On the other hand, all tested antioxidants had less or no effect on mycelial dry weight and mycelial leaner growth. On the contrary, all chemicals much reduced spore formation in both Fusarium species at 100 or 200 ppm and the inhibitory effect of antioxidants increased with increasing their concentrations.

  13. Control of Root Rot and Wilt Diseases of Roselle under Field Conditions

    Science.gov (United States)

    Hassan, Naglaa; Elsharkawy, Mohsen Mohamed; Shimizu, Masafumi

    2014-01-01

    Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle. PMID:25606010

  14. Control of Root Rot and Wilt Diseases of Roselle under Field Conditions.

    Science.gov (United States)

    Hassan, Naglaa; Elsharkawy, Mohsen Mohamed; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-12-01

    Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle.

  15. Effects of Soil Water Content on Cotton Root Growth and Distribution Under Mulched Drip Irrigation

    Institute of Scientific and Technical Information of China (English)

    HU Xiao-tang; CHEN Hu; WANG Jing; MENG Xiao-bin; CHEN Fu-hong

    2009-01-01

    The relation between soil water content and the growth of cotton root was studied for the scheme of field water and cotton yield under mulched drip irrigation.Based on the field experiments,three treatments of soil water content were conducted with 90%θf,75%θf,and 60%θf (θf is field water capacity).Cotton roots and root-shoot ratio were studied with digging method,and the soil moisture was observed with TDR (time domain reflector),and cotton yield was measured.The results indicated that the growth of cotton root accorded with Logistic growth curve in the three treatments,the cotton root grew quickly and its weight was very high under 75%θf because of the suitable soil water condition,while grew slowly and its weight was lower under 90%θf due to water moisture beyond the suitable condition,and the root weight was in between under 60%θf.For the three water treatments,the cotton root weight decreased with soil depth,and decreased more significantly in deeper soil layer with the soil moisture increasing.And the ratio of cotton root weight in 0-30 cm soil layer to the total root weight was the highest under 75%θf.The cotton root system was distributed mainly in the soil of narrow row and wide row mulched with plastic film,and little in the soil outside plastic film.The weight of cotton root was the highest in the soil of narrow row or wide row mulched with plastic film under 75%θf.Root-shoot ratio decreased with the soil moisture increasing.The soil water content affected cotton yields,and cotton yield was the highest under 75%θf.The higher soil moisture level is unfavorable to the growth of cotton root system and yield of cotton under mulched drip irrigation.

  16. Diaporthaceae associated with root and crown rot of maize

    NARCIS (Netherlands)

    Lamprecht, S.C.; Crous, P.W.; Groenewald, J.Z.; Tewoldemedhin, Y.T.; Marasas, W.F.O.

    2011-01-01

    Several isolates of coelomycetous fungi with pigmented conidia were consistently isolated from diseased roots of Zea mays in irrigated plots monitored in the KwaZulu-Natal Province of South Africa. Based on their morphology, these isolates could be identified as representative of Stenocarpella macro

  17. The Genetic Structure of Phellinus noxius and Dissemination Pattern of Brown Root Rot Disease in Taiwan.

    Science.gov (United States)

    Chung, Chia-Lin; Huang, Shun-Yuan; Huang, Yu-Ching; Tzean, Shean-Shong; Ann, Pao-Jen; Tsai, Jyh-Nong; Yang, Chin-Cheng; Lee, Hsin-Han; Huang, Tzu-Wei; Huang, Hsin-Yu; Chang, Tun-Tschu; Lee, Hui-Lin; Liou, Ruey-Fen

    2015-01-01

    Since the 1990s, brown root rot caused by Phellinus noxius (Corner) Cunningham has become a major tree disease in Taiwan. This fungal pathogen can infect more than 200 hardwood and softwood tree species, causing gradual to fast decline of the trees. For effective control, we must determine how the pathogen is disseminated and how the new infection center of brown root rot is established. We performed Illumina sequencing and de novo assembly of a single basidiospore isolate Daxi42 and obtained a draft genome of ~40 Mb. By comparing the 12,217 simple sequence repeat (SSR) regions in Daxi42 with the low-coverage Illumina sequencing data for four additional P. noxius isolates, we identified 154 SSR regions with potential polymorphisms. A set of 13 polymorphic SSR markers were then developed and used to analyze 329 P. noxius isolates collected from 73 tree species from urban/agricultural areas in 14 cities/counties all around Taiwan from 1989 to 2012. The results revealed a high proportion (~98%) of distinct multilocus genotypes (MLGs) and that none of the 329 isolates were genome-wide homozygous, which supports a possible predominant outcrossing reproductive mode in P. noxius. The diverse MLGs exist as discrete patches, so brown root rot was most likely caused by multiple clones rather than a single predominant strain. The isolates collected from diseased trees near each other tend to have similar genotype(s), which indicates that P. noxius may spread to adjacent trees via root-to-root contact. Analyses based on Bayesian clustering, FST statistics, analysis of molecular variance, and isolation by distance all suggest a low degree of population differentiation and little to no barrier to gene flow throughout the P. noxius population in Taiwan. We discuss the involvement of basidiospore dispersal in disease dissemination.

  18. The Genetic Structure of Phellinus noxius and Dissemination Pattern of Brown Root Rot Disease in Taiwan.

    Directory of Open Access Journals (Sweden)

    Chia-Lin Chung

    Full Text Available Since the 1990s, brown root rot caused by Phellinus noxius (Corner Cunningham has become a major tree disease in Taiwan. This fungal pathogen can infect more than 200 hardwood and softwood tree species, causing gradual to fast decline of the trees. For effective control, we must determine how the pathogen is disseminated and how the new infection center of brown root rot is established. We performed Illumina sequencing and de novo assembly of a single basidiospore isolate Daxi42 and obtained a draft genome of ~40 Mb. By comparing the 12,217 simple sequence repeat (SSR regions in Daxi42 with the low-coverage Illumina sequencing data for four additional P. noxius isolates, we identified 154 SSR regions with potential polymorphisms. A set of 13 polymorphic SSR markers were then developed and used to analyze 329 P. noxius isolates collected from 73 tree species from urban/agricultural areas in 14 cities/counties all around Taiwan from 1989 to 2012. The results revealed a high proportion (~98% of distinct multilocus genotypes (MLGs and that none of the 329 isolates were genome-wide homozygous, which supports a possible predominant outcrossing reproductive mode in P. noxius. The diverse MLGs exist as discrete patches, so brown root rot was most likely caused by multiple clones rather than a single predominant strain. The isolates collected from diseased trees near each other tend to have similar genotype(s, which indicates that P. noxius may spread to adjacent trees via root-to-root contact. Analyses based on Bayesian clustering, FST statistics, analysis of molecular variance, and isolation by distance all suggest a low degree of population differentiation and little to no barrier to gene flow throughout the P. noxius population in Taiwan. We discuss the involvement of basidiospore dispersal in disease dissemination.

  19. The Growth of Root Rot Disease on Pepper Seed Applied by Trichoderma Harzianum Inoculum

    Directory of Open Access Journals (Sweden)

    S. Sofian

    2013-06-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Root rot disease on pepper caused by Phytophthora capsici is one of the most important diseases on pepper. The using of antagonistic fungus of Trichoderma harzianum as a biological control agent of the pathogen is one of the important alternatives in controlling P. capsici without causing negative effects on the environment. The objectives of the research were to study about the ability of T. harzianum inoculum application in inhibiting the development of root-rot disease, influenced the growth of pepper seed, to studythe effective length time application of T. harzianum inoculum in inhibiting the development of root rot disease, and increased the growth of pepper seedlings. This research was arranged in a completely randomized design, with five treatments of length time application of T. harzianum inoculum i.e. control treatment without applicationtime of T. harzianum inoculum (K, application time of T. harzianum inoculum for 0 week (S0, application time of T. harzianum inoculum for 1 week (S1, application time of T. harzianum inoculum for two weeks (S2, application time of T. harzianum inoculum for three weeks (S3, and application time of T. harzianum inoculum for 4 weeks (S4 before planting. Each treatment was repeated15 times. The observed parameterswere disease percentage, the inhibition of antagonistic fungus, disease infection rate, plant height, number of leaves, wet and dry weight of plant, stem and leaves on pepper seed, and P. capsici population density. The result showed that application time of T. harzianum inoculumfor 4 weeks (S4 before planting is the most effective time in inhibiting the development of root rot disease than the other treatment sand also had significant effect on increasing the growth of pepper seed. The antagonism test showed that T. harzianum could inhibit P. capsiciin vitro. This result proves that application time of T. harzianum inoculums

  20. The use of root gall ratings to determine high risk zones in cotton fields infested by Meloidogyne Incognita

    Science.gov (United States)

    Cotton farmers need a reliable, accurate, and inexpensive method for determining the potential threat of root-knot nematodes (RKN) to cotton within individual fields for site specific application of nematicides. Evaluation of cotton roots for RKN galling at harvest may be an alternative to soil ana...

  1. Relationship Between Piercing-Sucking Insect Control and Internal Lint and Seed Rot in Southeastern Cotton (Gossypium hirsutum L.).

    Science.gov (United States)

    Medrano, Enrique G; Bell, Alois A; Greene, Jeremy K; Roberts, Phillip M; Bacheler, Jack S; Marois, James J; Wright, David L; Esquivel, Jesus F; Nichols, Robert L; Duke, Sara

    2015-08-01

    In 1999, crop consultants scouting for stink bugs (Hemiptera spp.) in South Carolina discovered a formerly unobserved seed rot of cotton that caused yield losses ranging from 10 to 15% in certain fields. The disease has subsequently been reported in fields throughout the southeastern Cotton Belt. Externally, diseased bolls appeared undamaged; internally, green fruit contain pink to dark brown, damp, deformed lint, and necrotic seeds. In greenhouse experiments, we demonstrated transmission of the opportunistic bacterium Pantoea agglomerans by the southern green stink bug, Nezara viridula (L.). Here, green bolls were sampled from stink bug management plots (insecticide protected or nontreated) from four South Atlantic coast states (North Carolina, South Carolina, Georgia, and Florida) to determine disease incidence in the field and its association with piercing-sucking insects feeding. A logistic regression analysis of the boll damage data revealed that disease was 24 times more likely to occur (P = 0.004) in bolls collected from plots in Florida, where evidence of pest pressure was highest, than in bolls harvested in NC with the lowest detected insect pressure. Fruit from plots treated with insecticide, a treatment which reduced transmission agent numbers, were 4 times less likely to be diseased than bolls from unprotected sites (P = 0.002). Overall, punctured bolls were 125 times more likely to also have disease symptoms than nonpunctured bolls, irrespective of whether or not plots were protected with insecticides (P = 0.0001). Much of the damage to cotton bolls that is commonly attributed to stink bug feeding is likely the resulting effect of vectored pathogens. Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by US Government employees and is in the public domain in the US.

  2. Basal Root Rot, a new Disease of Teak (Tectona grandis in Malaysia caused by Phellinus noxius

    Directory of Open Access Journals (Sweden)

    Mohd Farid, A.

    2005-01-01

    Full Text Available Basal root rot of teak was first reported from Sabak Bernam, Selangor making this the first report of the disease on teak in Peninsular Malaysia. The fungus found associated with the disease was Phellinus noxious. The disease aggressively killed its host irrespective of the host health status. Bark depression at the root collar which was visible from a distance was the characteristic symptom and the main indicator in identifying the disease in the plantation since above ground symptoms of the canopy could not be differentiated from crowns of healthy trees. However, although above ground symptoms were not easily discernible, the disease was already advanced and the trees mostly beyond treatment; 3.4 % of the trees in the plantation were affected and the disease occurred both on solitary trees and in patches. Below ground, infected trees had rotted root systems, mainly below and around the collar region with brown discolored wood and irregular golden-brown honeycomb-like pockets of fungal hyphae in the wood. Pathogenicity tests showed that the fungus produced symptoms similar to those observed in the plantation and killed two year-old teak plants. The disease killed all the inoculated hosts within three months, irrespective of wounded or unwounded treatments.

  3. Selection of potential antagonists against asparagus crown and root rot caused by Fusarium spp.

    Science.gov (United States)

    Rubio-Pérez, E; Molinero-Ruiz, M L; Melero-Vara, J M; Basallote-Ureba, M J

    2008-01-01

    Crown and root rot is one of the most important diseases of asparagus crop worldwide. Fusarium oxysporum f.sp. asparagi and F. proliferatum are the two species more frequently associated to this complex and their prevalence depends on the production area. The control of the disease on asparagus crop is difficult to achieve because its perennial condition and the long survival of the pathogen in the soil as chlamydospores or as mycelium in infected plant debris. Furthermore, Fusarium spp. are easily disseminated with asparagus propagation materials. Thus, control measures should aim at obtaining seedlings protection for longer than achieved with conventional pre-planting chemical treatments. The effectiveness of fungal antagonists on the control of diseases caused by soil borne fungi has been reported. The potential of Trichoderma spp. as a biological control agent against diseases caused by Fusarium spp. in tomato and asparagus has been studied . It has been suggested that microorganisms isolated from the root or rhizosphere of a specific crop may be better adapted to that crop and may provide better disease control than organisms originally isolated from other plant species. The objective of this work was the evaluation of the potential of fungal isolates from symptomless asparagus plants as biocontrol agents of Fusarium crown and root rot.

  4. Etiology and epidemiology of Pythium root rot in hydroponic crops: current knowledge and perspectives

    Directory of Open Access Journals (Sweden)

    John Clifford Sutton

    2006-09-01

    Full Text Available The etiology and epidemiology of Pythium root rot in hydroponically-grown crops are reviewed with emphasis on knowledge and concepts considered important for managing the disease in commercial greenhouses. Pythium root rot continually threatens the productivity of numerous kinds of crops in hydroponic systems around the world including cucumber, tomato, sweet pepper, spinach, lettuce, nasturtium, arugula, rose, and chrysanthemum. Principal causal agents include Pythium aphanidermatum, Pythium dissotocum, members of Pythium group F, and Pythium ultimum var. ultimum. Perspectives are given of sources of initial inoculum of Pythium spp. in hydroponic systems, of infection and colonization of roots by the pathogens, symptom development and inoculum production in host roots, and inoculum dispersal in nutrient solutions. Recent findings that a specific elicitor produced by P. aphanidermatum may trigger necrosis (browning of the roots and the transition from biotrophic to necrotrophic infection are considered. Effects on root rot epidemics of host factors (disease susceptibility, phenological growth stage, root exudates and phenolic substances, the root environment (rooting media, concentrations of dissolved oxygen and phenolic substances in the nutrient solution, microbial communities and temperature and human interferences (cropping practices and control measures are reviewed. Recent findings on predisposition of roots to Pythium attack by environmental stress factors are highlighted. The commonly minor impact on epidemics of measures to disinfest nutrient solution as it recirculates outside the crop is contrasted with the impact of treatments that suppress Pythium in the roots and root zone of the crop. New discoveries that infection of roots by P. aphanidermatum markedly slows the increase in leaf area and whole-plant carbon gain without significant effect on the efficiency of photosynthesis per unit area of leaf are noted. The platform of

  5. The effect of mangroves amendments to soil on root rot and root knot of potato (Solanum tuberosum L.

    Directory of Open Access Journals (Sweden)

    Marium Tariq

    2012-12-01

    Full Text Available Leaves, stem and pneumatophore of Avicennia marina and leaves and stem of Rhizophora mucronata were used as the organic amendments at 0.1, 1 and 5% concentrations in the control of root rot fungi like (Fusarium spp., Rhizoctonia solani and Macrophomina phasoelina and root knot nematode Meloidogyne javanica on potato. In pot experiments, germination of seeds, shoot length, shoot weight, root length, root weight and number of knots were significantly increased when plant parts like leaves, stem and pneumatophore of A. marina and R. mucronata were used at 1 and 5% concentrations. There was a complete suppression in infection of R. solani and M. phaseolina when A. marina and R. mucronata were used at 5% concentration on potato. Maximum inhibition of knots of M. javanica was observed when powder made from mangrove plant parts was used at 1 and 5% concentrations. Powder from all plant parts, like leaves, stem and pneumatophore, was effective in suppression of root infecting fungi and root knot nematode.

  6. A combination of biocontrol agents improves the management of dry root rot (Macrophomina phaseolina in greengram

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    R. Thilagavathi

    2007-08-01

    Full Text Available The biocontrol agents Trichoderma viride (strains Tv1 and Tv13, Pseudomonas fluorescens (Pf1 and Py15 and Bacillus subtilis (Bs16 were tested individually and in combination for their effectiveness against root rot of greengram caused by Macrophomina phaseolina. As regards the compatibility of the biocontrol agents with each other, T. viride strains were not compatible with B. subtilis (Bs16, but P. fluorescens strains were compatible with B. subtilis and T. viride. Of the biocontrol agents tested in vitro against M. phaseolina, combinations of P. fluorescens+T. viride (Pf1+Tv1, Pf1+Tv13 and Py15+Tv1 inhibited mycelial growth of the pathogen and they also promoted the growth of the greengram seedlings. A combination of Pf1+Tv1 was most effective in reducing root rot incidence under glass-house and field conditions as compared with other single or combined treatments or the untreated control. The activity of the defense-related enzymes peroxidase, polyphenol oxidase and phenyl alanine ammonia lyase was significantly greater in greengram plants treated with a talc based formulation containing Pf1+Tv1 followed by Pf1+Tv13 and Py15+Tv1, than in plants receiving other treatments or the untreated control. Moreover, a combination of Pf1+Tv1 followed by Pf1+Tv13 and Py15+Tv1 significantly increased yield under glass house and field conditions.

  7. Efficacy of Chaetomium Species as Biological Control Agents against Phytophthora nicotianae Root Rot in Citrus.

    Science.gov (United States)

    Hung, Phung Manh; Wattanachai, Pongnak; Kasem, Soytong; Poeaim, Supattra

    2015-09-01

    Thailand is one of the largest citrus producers in Southeast Asia. Pathogenic infection by Phytophthora, however, has become one of major impediments to production. This study identified a pathogenic oomycete isolated from rotted roots of pomelo (Citrus maxima) in Thailand as Phytophthora nicotianae by the internal transcribed spacer ribosomal DNA sequence analysis. Then, we examined the in vitro and in vivo effects of Chaetomium globosum, Chaetomium lucknowense, Chaetomium cupreum and their crude extracts as biological control agents in controlling this P. nicotianae strain. Represent as antagonists in biculture test, the tested Chaetomium species inhibited mycelial growth by 50~56% and parasitized the hyphae, resulting in degradation of P. nicotianae mycelia after 30 days. The crude extracts of these Chaetomium species exhibited antifungal activities against mycelial growth of P. nicotianae, with effective doses of 2.6~101.4 µg/mL. Under greenhouse conditions, application of spores and methanol extracts of these Chaetomium species to pomelo seedlings inoculated with P. nicotianae reduced root rot by 66~71% and increased plant weight by 72~85% compared to that in the control. The method of application of antagonistic spores to control the disease was simple and economical, and it may thus be applicable for large-scale, highly effective biological control of this pathogen.

  8. The preventive Control of White Root Rot Disease in Small Holder Rubber Plantation Using Botanical, Biological and Chemical Agents

    Directory of Open Access Journals (Sweden)

    Joko Prasetyo

    2014-03-01

    Full Text Available The preventive control of white root rot disease in small holder plantation using botanical, biological, and chemical agents. A field and laboratory experiment were conducted from June 2008 to December 2009 in Panumangan, Tulang Bawang - Lampung. The  field experiment was intended to evaluate the effect of  botanical plants (Alpinia galanga, Sansiviera auranthii, and Marantha arundinacea, biological agents (organic matter and Trichoderma spp., and chemical agents (lime and natural sulphur on the incidence of white root rot disease and population of some soil microbes. The laboratory experiment was conducted  to observe the mechanism of botanical agents  in controlling white root rot disease. In the field experiment, the treatments were applied  in the experimental plot with cassava plant infection as the indicator. The variables  examined were the incidence of  white root rot and population of soil microbes. In the laboratory experiment, culture of R. microporus was grown in PDA containing root exudate of the antagonistic plant (botanical agent. The variable examined was colony diameter of R. microporus growing in the PDA plates. The results of the  field experiment  showed that planting of the botanical agents, and application of Trichoderma spp., as well as natural sulphur, decreased the incidence of white root rot disease. The effectiveness of M. arundinacea and Trichoderma spp. was comparable to natural  sulphur. The laboratory experiment showed only root exudate of  A. galanga and  S. auranthii that were significantly inhibit the growth of R. microporus.

  9. Adaptive expression of host cell wall degrading enzymes in fungal disease: an example from Fusarium root rot of medicinal Coleus.

    Science.gov (United States)

    Bhattacharya, A

    2013-12-15

    Quantity of extracellular proteins and activities two cell wall degrading enzymes pectinase and cellulase were determined in the culture filtrate of Fusarium solani, the causal organism of root rot of Coleus forskohlii. Substitution of carbon source in the medium with either pectin or carboxymethyl cellulose led to the increased production of extracellular proteins by the fungus. Pectinase and cellulase activity in the culture filtrate was detected only when the growth medium contained substituted carbon source in the form of pectin and CMC, respectively. Pectinase activity was highest after 5 days incubation and then decreased gradually with time but cellulase activity showed a steady time dependent increase. In vitro virulence study showed the requirement of both the enzymes for complete expression of rot symptoms on Coleus plants. Thus the present study established the adaptive, substrate dependent expression of the two enzymes by the fungus and also their involvement in the root rot disease of Coleus forskohlii.

  10. Potassium supply to cotton roots as affected by potassium fertilization and liming

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    Rosolem Ciro Antonio

    2003-01-01

    Full Text Available Cotton (Gossypium hirsutum is known to have a high requirement for K and to be very sensitive to low soil pH. Most of K reaches plant roots by diffusion in the soil. As K interacts with Ca and Mg, liming can interfere in K movement in the soil, affecting eventually the plant nutrition. The objective of this work was to study the effect of dolomitic lime and 0, 15, 30, 45 and 60 g kg-1 of K on the supply of K to cotton roots. Cotton plants were grown up to 40 days in 5 L pots containing a Dark Red Latosol (Typic Haplusthox with 68% and 16% of sand and clay, respectively. There was an increase in dry matter yields and in K accumulation due to K fertilization. Root interception of soil K was also increased by K application, but was not affected by lime. Mass flow and diffusion increased linearly with K levels up to 60 mg kg-1, in pots with lime. In pots without lime the amount of K reaching the roots by diffusion increased up to 45 mg kg-1, but decreased at the highest K level. Accordingly, there was more K reaching the roots through mass flow at the highest K level. This happened because there were more fine roots in pots without lime, at the highest K level. As the roots grew closer, there was a stronger root competition leading to a decrease in the amount of K diffused to cotton roots.

  11. The effects of cotton root exudates on the growth and development of Verticillium dahliae

    Institute of Scientific and Technical Information of China (English)

    Yuxiang WU; Weiping FANG; Shuijin ZHU; Kuiying JIN; Daofan JI

    2008-01-01

    The effects of upland cotton root exudates on the growth and development of Verticillium dahliae were studied, through the compared analysis of the root exudates components between the resistant and suscept-ive cotton materials, using a pair of resistant and sus-ceptive isogenic lines to Verticillium wilt, Z5629 and Z421, as well as 4 other upland cotton cultivars with different resistant levels of Verticillium wilt. The results showed that the amino acids in the root exudates of the resistant cultivars were much less than that of the sus-ceptible ones. Compared with the susceptible ones, there were a lack of aspartic acid, threonine, glutamic acid, alanine, isoleucine, leucine, phenylalanine, lysine and proline in the root exudates from the resistant cul-tivars. On the contrary, arginine was lacking in the sus-ceptive cultivars. The saccharide types in the root exudates were no different between the two kinds of cultivars, but the contents of glucose, fructose and suc-rose in the root exudates of the susceptible varieties were much higher than those in the resistant ones. The experiment of Verticillium dahliae culture showed that the cotton root exudates from resistant cultivars can effectively restrain the spore germination and mycelium growth of Verticillium dahliae, and the argi-nine was the leading amino acid in this inhibitory action, besides the nutrition of the root exudates. However, the cotton root exudates from the susceptive cotton cultivars can improve the growth and develop-ment of Verticillium dahliae effectively; among the amino acid in the exudates, alanine was the most active one in this stimulating function.

  12. Wilt, crown, and root rot of common rose mallow (Hibiscus moscheutos) caused by a novel Fusarium sp.

    Science.gov (United States)

    A new crown and root rot disease of landscape plantings of the malvaceous ornamental common rose mallow (Hibiscus moscheutos) was first detected in Washington State in 2012. The main objectives of this study were to identify the causal agent using multilocus molecular phylogenetics and to complete K...

  13. Gene-for-gene relationships between strawberry and the causal agent of red stele root rot, Phytophthora fragariae var. fragariae.

    NARCIS (Netherlands)

    Weg, van de W.E.

    1997-01-01

    Red stele (red core) root rot is the major soil-borne disease of strawberries (Fragaria spp.) in many areas with cool, moist soil conditions. It is caused by the soil-borne fungus Phytophthora fragariae var. fragariae. Red stele is a quarantine disease in Europe with a zero tolerance for commercial

  14. Conduciveness of different soilless growing media to Pythium root and crown rot of cucumber under near-commercial conditions

    NARCIS (Netherlands)

    Gaag, van der D.J.; Wever, G.

    2005-01-01

    Substrates made from rockwool, coir dust, pumice and perlite were compared for conduciveness to Pythium root and crown rot in cucumber under near-commercial conditions. Rockwool slabs of 7 cm height were more conducive to the Pythium disease than coir dust slabs, pumice or perlite under these condit

  15. Effect of cultural practices and fungicide treatments on the severity of Phytophthora root rot of blueberries grown in Mississippi

    Science.gov (United States)

    Phytophthora root rot is an important disease of blueberries, especially those grown in areas with poor drainage. Reliable cultural and chemical management strategies are needed for control of this disease. Two studies were conducted to evaluate the effects of cultural practices and fungicide treat...

  16. Occurrence of the root-rot pathogen, Fusarium commune, in forest nurseries of the midwestern and western United States

    Science.gov (United States)

    Mee-Sook Kim; Jane E. Stewart; R. Kasten Dumroese; Ned B. Klopfenstein

    2012-01-01

    Fusarium commune can cause damping-off and root rot of conifer seedlings in forest nurseries, and this pathogen has been previously reported from Oregon, Idaho, and Washington, USA. We collected Fusarium isolates from additional nurseries in the midwestern and western USA to more fully determine occurrence of this pathogen. We used DNA sequences of the mitochondrial...

  17. Isolates of Rhizoctonia solani can produce both web blight and root rot symptoms in common bean (Phaseolus vulgaris L.)

    Science.gov (United States)

    Rhizoctonia solani Kühn (Rs) is an important pathogen in the tropics, causing web blight (WB), and a widespread soil-borne root rot (RR) pathogen of common bean (Phaseolus vulgaris L.) worldwide. This pathogen is a species complex classified into 14 anastomosis groups (AG). Some AGs have been report...

  18. The prevalence of different strains of Rhizoctonia solani associated with Rhizoctonia crown and root rot symptoms in Ontario sugarbeet fields

    Science.gov (United States)

    Rhizoctonia crown and root rot (RCRR) [Rhizoctonia solani Kühn] is an important disease of sugarbeets in southwestern Ontario, Canada. A survey of commercial sugarbeet fields was completed in 2010 and 2011 to determine the range of R. solani anastomosis groups (AGs) and inter-specific groups (ISGs) ...

  19. ROOT ROT OF CHILLI INCITED BY Sclerotium rolfsii Sacc. AND ITS MANAGEMENT- A REVIEW

    Directory of Open Access Journals (Sweden)

    V.Madhuri

    2014-02-01

    Full Text Available Chilli (Capsicum annum L. belongs to the family solanaceae is mainly cultivated for its vegetable green fruits and dry chilli as the spice. It is believed to be originated from South America. It is a rich source of Vitamin C, A and B. Chilli is valued for pungency which is imparted by an alkaloid, Capsaicin and the red pigments (Capsanthin, Capsorubin and Capxanthin. Chillies are widely used as spice, condiment, culinary, supplement, medicine, vegetable and are ornamental plants too. It is an important food flavouring ingredientfor flavouring many vegetarian and non-vegetarian food products. In view of its multifarious uses, the demand for chillies has been on the increase world over. In India it is an important cash crop, which is grown for the domestic market and for export. In India, chillies are grown in almost all states of the country and the major growing states in terms of production are Andhra Pradesh, Karnataka, Orissa, Maharashtra, West Bengal, Rajasthan and Tamil Nadu. There are several varieties of chilli cultivated in India. The most popular among these are, Sannam, LC334, Byadagi, Wonderhot, Jwala etc. The crop suffers from many diseases like damping off, anthracnose or fruit rot or dieback, wilt, leaf spots and powdery mildew. Among the fungal diseases, root rot of chilli caused by Sclerotium rolfsii has attained the economic importance. In recent years, this disease is causing the economic losses in chillies crop (Kalmesh and Gurjar 2001.

  20. A Simple Method for Assessing Severity of Common Root Rot on Barley

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    Mohammad Imad Eddin Arabi

    2013-12-01

    Full Text Available Common root rot caused by Cochliobolus sativus is a serious disease of barley. A simple and reliable method for assessing this disease would enhance our capacity in identifying resistance sources and developing resistant barley cultivars. In searching for such a method, a conidial suspension of C. sativus was dropped onto sterilized elongated subcrown internodes and incubated in sandwich filter paper using polyethylene transparent envelopes. Initial disease symptoms were easily detected after 48h of inoculation. Highly significant correlation coefficients were found in each experiment (A, B and C between sandwich filter paper and seedling assays, indicating that this testing procedure was reliable. The method presented facilitates a rapid pre-selection under uniform conditions which is of importance from a breeder’s point of view.

  1. Unconventional alternatives for control of tomato root rot caused by Rhizoctonia solani under greenhouse conditions

    Directory of Open Access Journals (Sweden)

    Hamza Amany

    2016-07-01

    Full Text Available This study was done to assess the antifungal effect of some biocontrol agents effective microorganisms (EMs1, Pseudomonas fluorescens, and Bacillus pumilus, titanium dioxide (TiO2 nanoparticles, black cumin and wheat germ oils as well as the recommended fungicide (flutolanil against root rot of tomato. Moreover, gas chromatography-mass spectrometry (GC-MS examination was completed to identify the bioactive compounds in plant oils (dark cumin and wheat germ. Also the impact of these medicines on some biochemical and growth parameters of tomato was examined. Flutolanil was the best treatment followed by dark cumin, TiO2, EMs1, Pseudomonas fluorescens, Bacillus pumilus and wheat germ oil, individually in both test seasons. The outcomes demonstrated a marked increase in each biochemical character (chlorophyll substance, peroxidase and polyphenoloxidase and plant development (height and fresh and dry weight under all the tried treatments in comparison to the controls.

  2. Primary structure of the histone 2B gene in the white root rot fungus, Rosellinia necatrix.

    Science.gov (United States)

    Aimi, Tadanori; Taguchi, Hiroyuki; Morinaga, Tsutomu

    2002-12-01

    The nucleotide sequence of the histone 2B (H2B) gene in the white root rot fungus, Rosellinia necatrix, was determined. The gene has two introns in the coding region at positions conserved in the Neurospora crassa and Aspergillus nidulans H2B genes, but the third intron present in the H2B gene from N. crassa and A. nidulans is absent in the R. necatrix H2B gene. The amino acid sequence of the coding region of the R. necatrix gene resembled that of N. crassa and A. nidulans. Therefore, the third intron in the H2B gene of N. crassa and A. nidulans may have been inserted into the present position after species diversification.

  3. FIRST REPORT OF Phytophthora nicotianae CAUSING ROOT ROT OF SOURSOP IN NORTHEASTERN BRAZIL

    Directory of Open Access Journals (Sweden)

    JAQUELINE FIGUEREDO DE OLIVEIRA COSTA

    Full Text Available ABSTRACT In 2013, soursop trees showing symptoms of root rot were observed in a field in Maceió, state of Alagoas, Brazil. It was isolated Phytophthora sp. which pathogenicity was confirmed in the host seedlings. Morphological and physiological characteristics in carrot-agar modified medium were consistent with Phytophthora nicotianae description. The PCR sequences products obtained with ITS1/ITS4 primers were compared to sequences of ribosomal DNA of Phytophthora species from the GenBank database observing high identity with other P. nicotianae isolates. A phylogenetic tree was performed to compare the isolate with other sequences of P. nicotianae, which clustering has been verified with 99% of bootstrap, confirming the morphophysiological studies. This is the first report of this pathogen on annonaceous plants in the Northeastern Brazil.

  4. Cadmium-induced Functional and Ultrastructural Alterations in Roots of Two Transgenic Cotton Cultivars

    Institute of Scientific and Technical Information of China (English)

    DAUD M K; SUN Yu-qiang; ZHU Shui-jin

    2008-01-01

    @@ The toxic effect of cadmium (Cd) at increasing concentrations has been studied with special attention being given to root morphological and ultrastructural changes in two transgenic cotton cultivars viz.BR001 and GK30 and their wild relative cotton genotype viz.Coker 312.In comparison to their respective controls,low concentration (10 and 100 M) of Cd greatly stimulated seed germination,while it was inhibited by highest concentration of Cd (1000 M) in case of two transgenic cultivars.

  5. Resistance in tomato and wild relatives to crown and root rot caused by Phytophthora capsici.

    Science.gov (United States)

    Quesada-Ocampo, L M; Hausbeck, M K

    2010-06-01

    Phytophthora capsici causes root, crown, and fruit rot of tomato, a major vegetable crop grown worldwide. The objective of this study was to screen tomato cultivars and wild relatives of tomato for resistance to P. capsici. Four P. capsici isolates were individually used to inoculate 6-week-old seedlings (1 g of P. capsici-infested millet seed per 10 g of soilless medium) of 42 tomato cultivars and wild relatives of tomato in a greenhouse. Plants were evaluated daily for wilting and death. All P. capsici isolates tested caused disease in seedlings but some isolates were more pathogenic than others. A wild relative of cultivated tomato, Solanum habrochaites accession LA407, was resistant to all P. capsici isolates tested. Moderate resistance to all isolates was identified in the host genotypes Ha7998, Fla7600, Jolly Elf, and Talladega. P. capsici was frequently recovered from root and crown tissue of symptomatic inoculated seedlings but not from leaf tissue or asymptomatic or control plants. The phenotype of the recovered isolate matched the phenotype of the inoculum. Pathogen presence was confirmed in resistant and moderately resistant tomato genotypes by species-specific polymerase chain reaction of DNA from infected crown and root tissue. Amplified fragment length polymorphisms of tomato genotypes showed a lack of correlation between genetic clusters and susceptibility to P. capsici, indicating that resistance is distributed in several tomato lineages. The results of this study create a baseline for future development of tomato cultivars resistant to P. capsici.

  6. Overexpression of a Foreign Bt Gene in Cotton Affects the Low-Molecular-Weight Components in Root Exudates

    Institute of Scientific and Technical Information of China (English)

    YAN Wei-Dong; SHI Wei-Ming; LI Bao-Hai; ZHANG Min

    2007-01-01

    Most research in the past using genetically modified crops (GM crops) has focused on the ecological safety of foreign gene (i.e., the gene flow), gene products (for example, Bt (Bacillus thuringiensis) protein), and the safety of transgenic food for humans. In this study, changes in both the species and amounts of low-molecular-weight components in cotton (Gossypium hirsutum L.) root exudates after foreign Bt gene overexpression were investigated under different nutritional conditions. Transgenic cotton containing Bt (Bt-cotton), supplemented with all the mineral nutrients, secreted more organic acids than the wild-type cotton (WT). When nitrogen was removed from the full-nutrient solution, the amount of organic acids secretion of Bt-cotton was lesser than that of WT. The roots of the transgenic cotton secreted lesser amounts of amino acids and soluble sugars than the WT roots in the full-nutrient solution. Deficiencies of P and K caused a large increase in the total amino acid and soluble sugar secretions of both Bt-cotton and WT, with larger increases observed in Bt-cotton. Because transferring the foreign Bt gene into cotton can result in alterations in the components of the root exudates, with the effect varying depending on the nutritional status, the cultivation of genetically modified crops, such as Bt-cotton, in soil environments should be more carefully assessed, and the possible effects as a result of the alterations in the root exudate components should be considered.

  7. GmPGIP3 enhanced resistance to both take-all and common root rot diseases in transgenic wheat.

    Science.gov (United States)

    Wang, Aiyun; Wei, Xuening; Rong, Wei; Dang, Liang; Du, Li-Pu; Qi, Lin; Xu, Hui-Jun; Shao, Yanjun; Zhang, Zengyan

    2015-05-01

    Take-all (caused by the fungal pathogen Gaeumannomyces graminis var. tritici, Ggt) and common root rot (caused by Bipolaris sorokiniana) are devastating root diseases of wheat (Triticum aestivum L.). Development of resistant wheat cultivars has been a challenge since no resistant wheat accession is available. GmPGIP3, one member of polygalacturonase-inhibiting protein (PGIP) family in soybean (Glycine max), exhibited inhibition activity against fungal endopolygalacturonases (PGs) in vitro. In this study, the GmPGIP3 transgenic wheat plants were generated and used to assess the effectiveness of GmPGIP3 in protecting wheat from the infection of Ggt and B. sorokiniana. Four independent transgenic lines were identified by genomic PCR, Southern blot, and reverse transcription PCR (RT-PCR). The introduced GmPGIP3 was integrated into the genomes of these transgenic lines and could be expressed. The expressing GmPGIP3 protein in these transgenic wheat lines could inhibit the PGs produced by Ggt and B. sorokiniana. The disease response assessments postinoculation showed that the GmPGIP3-expressing transgenic wheat lines displayed significantly enhanced resistance to both take-all and common root rot diseases caused by the infection of Ggt and B. sorokiniana. These data suggested that GmPGIP3 is an attractive gene resource in improving resistance to both take-all and common root rot diseases in wheat.

  8. Endophytic fungi harbored in Panax notoginseng: diversity and potential as biological control agents against host plant pathogens of root-rot disease

    Directory of Open Access Journals (Sweden)

    You-Kun Zheng

    2017-07-01

    Conclusion: Our results suggested that P. notoginseng harbors diversified endophytic fungi that would provide a basis for the identification of new bioactive compounds, and for effective biocontrol of notoginseng root rot.

  9. Dynamic QTL and epistasis analysis on seedling root traits in upland cotton.

    Science.gov (United States)

    Liang, Qingzhi; Li, Pengbo; Hu, Cheng; Hua, Hua; Li, Zhaohu; Rong, Yihua; Wang, Kunbo; Hua, Jinping

    2014-04-01

    Roots are involved in acquisition of water and nutrients, as well as in providing structural support to plant. The root system provides a dynamic model for developmental analysis. Here, we investigated quantitative trait loci (QTL), dynamic conditional QTL and epistatic interactions for seedling root traits using an upland cotton F2 population and a constructed genetic map. Totally, 37 QTLs for root traits, 35 dynamic conditional QTLs based on the net increased amount of root traits (root tips, forks, length, surface area and volume) (i) after transplanting 10 days compared to 5 days, and (ii) after transplanting 15 days to 10 days were detected. Obvious dynamic characteristic of QTL and dynamic conditional QTL existed at different developmental stages of root because QTL and dynamic conditional QTL had not been detected simultaneously. We further confirmed that additive and dominance effects of QTL qRSA-chr1-1 in interval time 5 to 10 DAT (days after transplant) offset the effects in 10 to 15 DAT. Lots of two-locus interactions for root traits were identified unconditionally or dynamically, and a few epistatic interactions were only detected simultaneously in interval time of 5-10 DAT and 10-15 DAT, suggesting different interactive genetic mechanisms on root development at different stages. Dynamic conditional QTL and epistasis effects provide new attempts to understand the dynamics of roots and provide clues for root architecture selection in upland cotton.

  10. Prevention and Control of Gentiana macrophylla Pall Root Rot Disease%秦艽根腐病的防治

    Institute of Scientific and Technical Information of China (English)

    程远辉; 侯志江; 徐中志

    2014-01-01

    The root rot is a major disease affecting yield of Gentiana macrophyl a pal , reducing yield or even causing total crop failure. This research introduced the occurrence characteristics and various control techniques of root rot of Gentiana macrophyl a pal , in order to provide references for farmers.%根腐病是影响秦艽产量的最主要病害,发病后会造成秦艽严重减产甚至绝收。笔者总结了秦艽根腐病的发生特点及各种防治技术,以期为广大药农提供指导。

  11. Wide variation in virulence and genetic diversity of binucleate Rhizoctonia isolates associated with root rot of strawberry in Western Australia.

    Directory of Open Access Journals (Sweden)

    Xiangling Fang

    Full Text Available Strawberry (Fragaria×ananassa is one of the most important berry crops in the world. Root rot of strawberry caused by Rhizoctonia spp. is a serious threat to commercial strawberry production worldwide. However, there is no information on the genetic diversity and phylogenetic status of Rhizoctonia spp. associated with root rot of strawberry in Australia. To address this, a total of 96 Rhizoctonia spp. isolates recovered from diseased strawberry plants in Western Australia were characterized for their nuclear condition, virulence, genetic diversity and phylogenetic status. All the isolates were found to be binucleate Rhizoctonia (BNR. Sixty-five of the 96 BNR isolates were pathogenic on strawberry, but with wide variation in virulence, with 25 isolates having high virulence. Sequence analysis of the internal transcribed spacers of the ribosomal DNA separated the 65 pathogenic BNR isolates into six distinct clades. The sequence analysis also separated reference BNR isolates from strawberry or other crops across the world into clades that correspond to their respective anastomosis group (AG. Some of the pathogenic BNR isolates from this study were embedded in the clades for AG-A, AG-K and AG-I, while other isolates formed clades that were sister to the clades specific for AG-G, AG-B, AG-I and AG-C. There was no significant association between genetic diversity and virulence of these BNR isolates. This study demonstrates that pathogenic BNR isolates associated with root rot of strawberry in Western Australia have wide genetic diversity, and highlights new genetic groups not previously found to be associated with root rot of strawberry in the world (e.g., AG-B or in Australia (e.g., AG-G. The wide variation in virulence and genetic diversity identified in this study will be of high value for strawberry breeding programs in selecting, developing and deploying new cultivars with resistance to these multi-genetic groups of BNR.

  12. Wide variation in virulence and genetic diversity of binucleate Rhizoctonia isolates associated with root rot of strawberry in Western Australia.

    Science.gov (United States)

    Fang, Xiangling; Finnegan, Patrick M; Barbetti, Martin J

    2013-01-01

    Strawberry (Fragaria×ananassa) is one of the most important berry crops in the world. Root rot of strawberry caused by Rhizoctonia spp. is a serious threat to commercial strawberry production worldwide. However, there is no information on the genetic diversity and phylogenetic status of Rhizoctonia spp. associated with root rot of strawberry in Australia. To address this, a total of 96 Rhizoctonia spp. isolates recovered from diseased strawberry plants in Western Australia were characterized for their nuclear condition, virulence, genetic diversity and phylogenetic status. All the isolates were found to be binucleate Rhizoctonia (BNR). Sixty-five of the 96 BNR isolates were pathogenic on strawberry, but with wide variation in virulence, with 25 isolates having high virulence. Sequence analysis of the internal transcribed spacers of the ribosomal DNA separated the 65 pathogenic BNR isolates into six distinct clades. The sequence analysis also separated reference BNR isolates from strawberry or other crops across the world into clades that correspond to their respective anastomosis group (AG). Some of the pathogenic BNR isolates from this study were embedded in the clades for AG-A, AG-K and AG-I, while other isolates formed clades that were sister to the clades specific for AG-G, AG-B, AG-I and AG-C. There was no significant association between genetic diversity and virulence of these BNR isolates. This study demonstrates that pathogenic BNR isolates associated with root rot of strawberry in Western Australia have wide genetic diversity, and highlights new genetic groups not previously found to be associated with root rot of strawberry in the world (e.g., AG-B) or in Australia (e.g., AG-G). The wide variation in virulence and genetic diversity identified in this study will be of high value for strawberry breeding programs in selecting, developing and deploying new cultivars with resistance to these multi-genetic groups of BNR.

  13. Research Progress of Root Rot Disease in Barley%大麦根腐病研究进展

    Institute of Scientific and Technical Information of China (English)

    兰国防; 张凤英; 包海柱; 武海明; 刘志萍

    2014-01-01

    As one of the most serious worldwide disease affecting the yield and quality of barley,Root Rot Disease was widely distribu-ted in the Daxinganling mountain area and the Yangtze River basin in China. Root Rot Disease in Barely is the fungal disease caused by Biplaris sorokiniana and its pathogenic bacteria can be parasitized and also can be saprophyticed with strong adaptability. This paper mainly reviewed the cause of root rot disease,its biological characteristics,host range,disease symptoms,identification of the disea-ses,genetics of resistance,and measures on how to control this disease as well as the outlook of the research prospects in root rot dis-ease in barley.%大麦根腐病是严重危害大麦产量和品质的世界性病害之一,在我国的大兴安岭西麓和长江流域分布广泛。大麦根腐病是由根腐离蠕孢菌( Biplaris sorokiniana)引起的真菌性病害,其致病菌可寄生也可腐生,适应性极强。本文主要从大麦根腐病的病原及其生物学特性、寄主范围、病害症状、病害鉴定、抗性遗传和防治方法等方面进行了综述,并展望了大麦根腐病的研究前景。

  14. Fusarium paranaense sp. nov., a member of the Fusarium solani species complex causes root rot on soybean in Brazil.

    Science.gov (United States)

    Costa, Sarah S; Matos, Kedma S; Tessmann, Dauri J; Seixas, Claudine D S; Pfenning, Ludwig H

    2016-01-01

    Isolates of Fusarium obtained from soybean plants showing symptoms of root rot collected in subtropical southern and tropical central Brazil were characterized based on phylogenetic analyses, sexual crossing, morphology, and pathogenicity tests. A novel species within the Fusarium solani species complex (FSSC) causing soybean root rot is formally described herein as Fusarium paranaense. This species can be distinguished from the other soybean root rot pathogens in the FSSC, which are commonly associated with soybean sudden death syndrome (SDS) based on analyses of the combined DNA sequences of translation elongation factor 1-α and the second largest subunit of RNA polymerase II and on interspecies mating compatibility. Bayesian and maximum parsimony phylogenetic analyses showed that isolates of F. paranaense formed a distinct group in clade 3 of the FSSC in contrast to the pathogens currently known to cause SDS, which are in clade 2. Female fertile tester strains were developed that can be used for the identification of this new species in the FSSC based on sexual crosses. All isolates were heterothallic and belonged to a distinct mating population. Fusarium tucumaniae, a known SDS pathogen, was found in the subtropical southern region of the country.

  15. Potential of Endophytic Fungi Isolated from Cotton Roots for Biological Control against Verticillium Wilt Disease

    Science.gov (United States)

    Wang, Lingfei; Li, Zhifang; Shi, Yongqiang; Zhao, LiHong; Feng, Zili; Zhu, Heqin

    2017-01-01

    Verticillium wilt is a soil-borne disease, and severely limits the development of cotton production. To investigate the role of endophytic fungi on Verticillium wilt, CEF-818 (Penicillium simplicissimum), CEF-714 (Leptosphaeria sp.), CEF-642 (Talaromyces flavus.) and CEF-193 (Acremonium sp.) isolated from cotton roots were used to assess their effects against cotton wilt disease caused by a defoliating V. dahliae strain Vd080. In the greenhouse, all treatments significantly reduced disease incidence and disease index, with the control efficacy ranging from 26% (CEF-642) to 67% (CEF-818) at 25 days (d) after inoculation. In the disease nursery, compared to controls (with disease incidence of 33.8% and disease index of 31), CEF-818, CEF-193, CEF-714 and CEF-642 provided a protection effect of 69.5%, 69.2%, 54.6% and 45.7%, respectively. Especially, CEF-818 and CEF-714 still provided well protection against Verticillium wilt with 46.9% and 56.6% or 14.3% and 33.7% at the first peak of the disease in heavily infected field, respectively (in early July). These results indicated that these endophytes not only delayed but also reduced wilt symptoms on cotton. In the harvest, the available cotton bolls of plant treated with CEF-818 and CEF-714 increased to 13.1, and 12.2, respectively. And the seed cotton yield significantly increased after seed bacterization with CEF-818 (3442.04 kg/ha) compared to untreated control (3207.51 kg/ha) by 7.3%. Furtherly, CEF-818 and CET-714 treatment increased transcript levels for PAL, PPO, POD, which leads to the increase of cotton defense reactions. Our results indicate that seed treatment of cotton plants with CEF-818 and CET-714 can help in the biocontrol of V. dahliae and improve seed cotton yield in cotton fields. This study provided a better understanding of cotton-endophyte interactions which will aid in developing effective biocontrol agents for Verticillium wilt of cotton in futhre. PMID:28107448

  16. Application of bacteria from non-cultivated plants to promote growth, alter root architecture and alleviate salt stress of cotton.

    Science.gov (United States)

    Irizarry, I; White, J F

    2017-04-01

    Cotton seeds are frequently treated with acid to remove fibres and reduce seed-transmitted diseases. This process also eliminates beneficial bacteria on the seed surface. The goal of this research was to seek and apply beneficial bacteria to acid delinted cotton seeds to evaluate their growth-promoting and salt stress alleviating effects in seedlings. Bacteria were isolated from non-cultivated plants in the Malvaceae. Seeds were collected from Portia tree (Thespesia populnea) and wild cotton (Gossypium hirsutum) from coastal and arid areas of Puerto Rico. Bacillus amyloliquefaciens, Curtobacterium oceanosedimentum and Pseudomonas oryzihabitans were inoculated onto acid delinted cotton seeds. Bacteria increased cotton seed germination and length of emerging seedling radicles. Cotton seeds were inoculated with B. amyloliquefaciens to evaluate growth and root architecture of non-stressed and salt stressed seedlings. Inoculating cotton seeds with B. amyloliquefaciens led to a greater percentage of seedlings with expanded cotyledons after 8 days, enhanced primary and lateral root growth, and altered root architecture. Similar results were obtained when okra seeds were inoculated with B. amyloliquefaciens. The data supported the hypothesis that non-cultivated plants in the Malvaceae growing in stressful environments possess bacteria that promote growth, alter root architecture and alleviate salt stress of cotton and okra seedlings. This study demonstrated the effects of applying beneficial bacteria on acid delinted cotton seeds. Inoculating seeds with salt stress alleviating bacteria could improve the growth of crop seedlings that are vulnerable to soil salinization. © 2017 The Society for Applied Microbiology.

  17. Variation in Sensitivity Among Some Isolates of Macrophomina phaseolina Isolated from Cotton Roots to Flutolanil Fungicide.

    Science.gov (United States)

    Mahmoud, Yehia A G; Aly, A A; Omar, M R; Ismail, Abdel-Wahab A

    2006-06-01

    Toxicity of the fungicide Flutolanil was in vitro tested against 20 isolates of Macrophomina phaseolina and cotton seedlings of ten commercial cotton cultivars. The isolates were recovered from roots of cotton plants obtained from different cotton-growing areas in Egypt. Most of the tested isolates were sensitive to Flutolanil; however, they varied in sensitivity. Twenty-five percent of the isolates were highly sensitive where IC50 ranged from 100 µg/ml. Flutolanil was very safe on both shoots and roots of the tested cultivars (IC50 > 100 µg/ml). Treating cotton seeds with Flutolanil resulted in highly significant (P < 0.01) reductions in pathogenicity of 18 isolates and a significant reduction (P < 0.05) in pathogenicity of isolate M29. M1 was the only isolate, which was insensitive to the application of Flutolanil. In vivo toxicity to Flutolanil was not correlated with its in vitro toxicity. However, a highly significant correlation (r = 0.60, P < 0.01) was observed between pathogenicity of isolates and the in vivo toxicity of the fungicide.

  18. Microbiota Characterization of Compost Using Omics Approaches Opens New Perspectives for Phytophthora Root Rot Control.

    Science.gov (United States)

    Blaya, Josefa; Marhuenda, Frutos C; Pascual, Jose A; Ros, Margarita

    2016-01-01

    Phytophthora root rot caused by Phytophthora nicotianae is an economically important disease in pepper crops. The use of suppressive composts is a low environmental impact method for its control. Although attempts have been made to reveal the relationship between microbiota and compost suppressiveness, little is known about the microorganisms associated with disease suppression. Here, an Ion Torrent platform was used to assess the microbial composition of composts made of different agro-industrial waste and with different levels of suppressiveness against P. nicotianae. Both bacterial and fungal populations responded differently depending on the chemical heterogeneity of materials used during the composting process. High proportions (67-75%) of vineyard pruning waste were used in the most suppressive composts, COM-A and COM-B. This material may have promoted the presence of higher relative abundance of Ascomycota as well as higher microbial activity, which have proved to be essential for controlling the disease. Although no unique fungi or bacteria have been detected in neither suppressive nor conducive composts, relatively high abundance of Fusarium and Zopfiella were found in compost COM-B and COM-A, respectively. To the best of our knowledge, this is the first work that studies compost metabolome. Surprisingly, composts and peat clustered together in principal component analysis of the metabolic data according to their levels of suppressiveness achieved. This study demonstrated the need for combining the information provided by different techniques, including metagenomics and metametabolomics, to better understand the ability of compost to control plant diseases.

  19. Short Rotations in Forest Plantations Accelerate Virulence Evolution in Root-Rot Pathogenic Fungi

    Directory of Open Access Journals (Sweden)

    Jean-Paul Soularue

    2017-06-01

    Full Text Available As disease outbreaks in forest plantations are causing concern worldwide, a clear understanding of the influence of silvicultural practices on the development of epidemics is still lacking. Importantly, silvicultural practices are likely to simultaneously affect epidemiological and evolutionary dynamics of pathogen populations. We propose a genetically explicit and individual-based model of virulence evolution in a root-rot pathogenic fungus spreading across forest landscapes, taking the Armillaria ostoyae–Pinus pinaster pathosystem as reference. We used the model to study the effects of rotation length on the evolution of virulence and the propagation of the fungus within a forest landscape composed of even-aged stands regularly altered by clear-cutting and thinning operations. The life cycle of the fungus modeled combines asexual and sexual reproduction modes, and also includes parasitic and saprotrophic phases. Moreover, the tree susceptibility to the pathogen is primarily determined by the age of the stand. Our simulations indicated that the shortest rotation length accelerated both the evolution of virulence and the development of the epidemics, whatever the genetic variability in the initial fungal population and the asexuality rate of the fungal species

  20. Zinc Induced Enzymatic Defense Mechanisms in Rhizoctonia Root Rot Infected Clusterbean Seedlings

    Directory of Open Access Journals (Sweden)

    Neha Wadhwa

    2014-01-01

    Full Text Available This investigation was planned to determine the effect of different concentrations of zinc (Zn on biochemical constituents of clusterbean, which play an important role in disease resistance mechanisms. Clusterbean seedlings were grown with 0, 10, or 20 mg Zn kg−1 soil treatments in earthen pots filled with 700 g inoculated soil. Soil was inoculated by pretreatment with 250 mg (wet weight of Rhizoctonia inoculums per pot. A similar set was maintained in uninoculated soil. Root rot incidence decreased to 41 and 27 per cent with 10 and 20 mg Zn kg−1 soil treatments, respectively, as compared to 68 percent at control. Antioxidative enzyme activity (polyphenol oxidase, peroxidase, phenylalanine ammonia lyase, and tyrosine ammonia lyase increased in inoculated seedlings and was increased further by 20 mg Zn kg−1 soil treatment. Antioxidative enzymes play an important role against fungal invasion, as peroxidase is involved in the formation of barrier via lignifications at the site of pathogen penetration. PAL and TAL play a key role in phenylpropanoid metabolism and could perform defense-related functions. Zn acts as a cofactor for these enzymes, so it can be concluded that Zn may be used as a soil-nutritive agent to increase resistance in plants against fungal diseases.

  1. Postharvest salicylic acid treatment reduces storage rots in water-stressed but no unstressed sugarbeet roots

    Science.gov (United States)

    Exogenous application of salicylic acid (SA) reduces storage rots in a number of postharvest crops. SA’s ability to protect sugarbeet (Beta vulgaris L.) taproots from common storage rot pathogens, however, is unknown. To determine the potential of SA to reduce storage losses caused by three common...

  2. Sequence composition and mapping of BACs of cotton homoeologous chromosomes 11 and 21

    Science.gov (United States)

    Interest in cotton chromosome 11 and its homoeologous chromosome 21 derives from the discovery of resistance (R) or pathogen-induced R genes underlying QTLs involved in root-knot nematode, reniform nematode, Fusarium wilt, Verticillium wilt, and black root rot resistance. Genetic and QTL mapping eff...

  3. Temperature, moisture, and fungicide effects in managing Rhizoctonia root and crown rot of sugar beet.

    Science.gov (United States)

    Bolton, Melvin D; Panella, Lee; Campbell, Larry; Khan, Mohamed F R

    2010-07-01

    Rhizoctonia solani AG-2-2 is the causal agent of Rhizoctonia root and crown rot in sugar beet; however, recent increases in disease incidence and severity were grounds to reevaluate this pathosystem. To assess the capacity at which other anastomosis groups (AGs) are able to infect sugar beet, 15 AGs and intraspecific groups (ISGs) were tested for pathogenicity on resistant ('FC708 CMS') and susceptible ('Monohikari') seedlings and 10-week-old plants. Several AGs and ISGs were pathogenic on seedlings regardless of host resistance but only AG-2-2 IIIB and AG-2-2 IV caused significant disease on 10-week-old plants. Because fungicides need to be applied prior to infection for effective disease control, temperature and moisture parameters were assessed to identify potential thresholds that limit infection. Root and leaf disease indices were used to evaluate disease progression of AG-2-2 IIIB- and AG-2-2 IV-inoculated plants in controlled climate conditions of 7 to 22 growing degree days (GDDs) per day. Root disease ratings were positively correlated with increasing temperature of both ISGs, with maximum disease symptoms occurring at 22 GDDs/day. No disease symptoms were evident from either ISG at 10 GDDs/day but disease symptoms did occur in plants grown in growth chambers set to 11 GDDs/day. Using growth chambers adjusted to 22 GDDs/day, disease was evaluated at 25, 50, 75, and 100% moisture-holding capacity (MHC). Disease symptoms for each ISG were highest in soils with 75 and 100% MHC but disease still occurred at 25% MHC. Isolates were tested for their ability to cause disease at 1, 4, and 8 cm from the plant hypocotyl. Only AG-2-2 IIIB was able to cause disease symptoms at 8 cm during the evaluation period. In all experiments, isolates of AG-2-2 IIIB were found to be more aggressive than AG-2-2 IV. Using environmental parameters that we identified as the most conducive to disease development, azoxystrobin, prothioconazole, pyraclostrobin, difenoconazole

  4. 油梨根腐病发病规律及防治技术%Occurrence regularity of Avocado Root Rot and Its Control Techniques

    Institute of Scientific and Technical Information of China (English)

    劳有德; 陈川

    2016-01-01

    油梨根腐病是油梨根部重要病害,近年来逐渐增多,严重时可造成油梨整株死亡,已成为油梨产业发展的重要病害。目前广西已发现有4种油梨根腐病,是较难防治的土传病害。重点介绍4种油梨根腐病的特点、发生、病因、症状等,从农业、物理、生物、化学防治方面介绍油梨根腐病的防治技术。%Avocado root rot is one of the most important root diseases on avocado, the disease is increasing in recent years. It can cause the death of the whole plant of avocado when this disease becomes seriously. The avocado root rot disease has become an important disease in avocado industry. Nowadays, there are four kinds of avocado root rot diseases are found in GuangXi Province. It is more difficult to control these soil borne diseases. This paper introduces the traits, causes, symptoms and occurrence of avocado root rot disease. And then, the control techniques for avocado root rot in agricultural, physical, biological and chemical control field and so on are introduced.

  5. Conjunctively screening of biocontrol agents (BCAs) against fusarium root rot and fusarium head blight caused by Fusarium graminearum.

    Science.gov (United States)

    Wang, Lu-Yao; Xie, Yue-Shen; Cui, Yuan-Yu; Xu, Jianjun; He, Wei; Chen, Huai-Gu; Guo, Jian-Hua

    2015-08-01

    Fusarium root-rot and fusarium head blight are plant diseases caused by Fusarium sp. in different growth periods of wheat, bring heavy losses to crop production in China. This research is aiming to screen biocontrol agents conjunctively for controlling these two diseases at the same time, as well as evaluate our previous BCAs (Biological Control Agents) screening strategies in more complex situation, considering biocontrol is well concerned as an environmental-friendly plant disease controlling method. Totally 966 bacterial isolates were screened from different parts of wheat tissues, of which potential biocontrol values were detected according to their abilities in antagonism inhibition and secreting extracellular hydrolytic enzyme. Biocontrol tests against fusarium root rot and fusarium head blight were carried out on 37 bacterial isolates with potential biocontrol capacity after pre-selection through ARDRA- and BOX-PCR analysis on strains with high assessment points. We acquired 10 BCAs with obvious biocontrol efficacy (more than 40%) in greenhouse and field tests. Pseudomonas fluorescens LY1-8 performed well in both two tests (biocontrol efficacy: 44.62% and 58.31%), respectively. Overall, correlation coefficient is 0.720 between assessment values of 37 tested BCA strains and their biocontrol efficacy in trails against fusarium root rot; correlation coefficient is 0.806 between their assessment values and biocontrol efficacy in trails against fusarium head blight. We acquired 10 well-performed potential BCAs, especially P. fluorescens LY1-8 displayed good biocontrol capacity against two different diseases on wheat. Biocontrol efficacies results in both greenhouse and field tests showed high positive correlation with assessment values (0.720 and 0.806), suggesting that the BCAs screening and assessing strategy previously developed in our lab is also adaptable for conjunctively screening BCAs for controlling both root and shoot diseases on wheat caused by same

  6. Heterobasidion annosum root rot in Picea abies: Variability in aggressiveness and resistance

    Energy Technology Data Exchange (ETDEWEB)

    Swedjemark, G.

    1995-12-31

    In greenhouse experiments 3-4 year-old plants of Picea abies and Pinus sylvestris were inoculated with the root rot fungus Heterobasidion annosum. The growth rates of 25 S and 14 P isolates of the fungus were measured in the sapwood of about 25 rametes each of 98 Norway spruce clones and in 150 seedlings each of Norway spruce and Scots pine. Correlations were determined between fungal sapwood growth and a variety of variables, i.e. the physical stage, growth rhythm, size and condition of the cuttings, provenance and the growth capacity of the clones estimated in field tests. Genetic parameters such as phenotypic and genotypic variance, genotypic coefficient of variance and broad sense heritability were calculated. H. annosum infection incidence was close to 100 % for inoculated Norway spruce clones, and the mortality rate was about 1 %. Fungal growth in sapwood differed significantly among clones and among fungal isolates. The genotypic correlation coefficient was large (30 %) and broad sense heritability was 0.35. This suggests that good selection progress can be achieved in breeding programs. The physical stage (bud-flush, vegetative and post bud-set stage) of the clones contributed significantly to the total variation in fungal growth. The population structure of H. annosum was studied in two 25-year-old, first generation stands of Norway spruce. The stands had been thinned one and seven years earlier, respectively. All stumps and remaining trees were sampled for H. annosum isolates. The isolates were tested with somatic incompatibility to detect single genets and the distribution of genets in the stand was determined. About 70 % of the 7-year-old thinning stumps were colonized by H, annosum, and 50 % of these stumps were colonized by more than one fungal genet. Sixty-three percent of the remaining trees were infected with H. annosum but among them there was only one genet per tree. 104 refs, 12 figs

  7. Contribution of Root Respiration to Total Soil Respiration in a Cotton Field of Northwest China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zhi-Min; ZHAO Cheng-Yi; Y.YILIHAMU; LI Ju-Yan; LI Jun

    2013-01-01

    To measure the contribution of root respiration (Rr) to total soil respiration (Rt) in arid cotton fields,eighteen plots,nine for girdling and nine control,were built in an arid cotton field in the Aksu National Experimental Station of Oasis Farmland Ecosystem,Xinjiang of China.Given the difference of soil respiration between girdled plots and non-girdled control plots,the components of soil respiration,root respiration (Rr) and respiration originating from decomposition (Rd) were divided.The temperature sensitivities of Rr and Rd were analyzed,respectively.The results showed that the average contribution of Rr to Rt in arid cotton field was about 32% during the study period.The temperature-response curve of Rr differed from that of Rd.The dynamic variation of Rd was more related to the change of soil temperature as compared to Rr.Rr and Rd had different responses to the variation of environment,and thus new models capable of differentiating between Rr and Rd are needed for evaluating the different factors controlling these two components of soil respiration in arid cotton field.

  8. Effect of corn steep liquor on lettuce root rot (Fusarium oxysporum f.sp. lactucae) in hydroponic cultures.

    Science.gov (United States)

    Chinta, Yufita D; Kano, Kazuki; Widiastuti, Ani; Fukahori, Masaru; Kawasaki, Shizuka; Eguchi, Yumi; Misu, Hideyuki; Odani, Hiromitsu; Zhou, Songying; Narisawa, Kazuhiko; Fujiwara, Kazuki; Shinohara, Makoto; Sato, Tatsuo

    2014-08-01

    Recent reports indicate that organic fertilisers have a suppressive effect on the pathogens of plants grown under hydroponic systems. Furthermore, microorganisms exhibiting antagonistic activity to diseases have been observed in organic hydroponic systems. This study evaluated the effect of corn steep liquor (CSL) on controlling lettuce root rot disease [Fusarium oxysporum f.sp. lactucae (FOL)] in a hydroponic system. The effect of CSL and Otsuka A (a chemical fertiliser) on the inhibition of FOL in terms of mycelial growth inhibition was tested in vivo. Addition of CSL suppressed FOL infection rates. CSL inhibited FOL infection by 26.3-42.5% from 2 days after starting incubation. In comparison, Otsuka A inhibited FOL growth by 5.5-19.4%. In addition, four of 10 bacteria isolated from the nutrient media containing CSL exhibited inhibition zones preventing FOL mycelial growth. We found that CSL suppressed FOL in lettuce via its antifungal and biostimulatory effects. We suggest that activation of beneficial microorganisms present in CSL may be used to decrease lettuce root rot disease and contribute to lettuce root growth. © 2014 Society of Chemical Industry.

  9. Effect of Potassium on Ultrastructure of Maize Stalk Pith and Young Root and Their Relation to Stalk Rot Resistance

    Institute of Scientific and Technical Information of China (English)

    LI Wen-juan; HE Ping; JIN Ji-yun

    2010-01-01

    To study the mechanism of potassium(K)application on improvement of maize resistance to stalk rot at cellular level,scanning electron microscope and transmission electron microscope were used to observe the effect of K on the ultrastructure of maize stalk pith tissue and young root tip cell influenced by K and pathogen.In K deficient treatment,parenchyma cells of stalk pith had abnormal structure,and the cell wall between upper and lower adjacent cell was damaged,resulting in the loss of connections between vascular cells and insufficient supporting capacity.However,an improved K nutrition helped to keep a quite tight arrangement of root cell with thick cell wall,and prevent the invasion of pathogen effectively.Moreover,K treated root cell had abundant golgi apparatus,which could excrete large amount of secretions to degrade mycelium.Papillary and highly electronic intensity dot were accumulated at the invading point to prevent the development of the mycelium.Improved K nutrition could increase the resistant ability of maize plant to stalk rot,through keeping cell structure stability,preventing the expansion of intracellular space to reduce the chances of pathogen invasions,and through reinforcing cell wall and formation of intercellular and intracellular material to restrict further development of pathogen in host cell.

  10. Root interactions in a maize/soybean intercropping system control soybean soil-borne disease, red crown rot.

    Directory of Open Access Journals (Sweden)

    Xiang Gao

    Full Text Available BACKGROUND: Within-field multiple crop species intercropping is well documented and used for disease control, but the underlying mechanisms are still unclear. As roots are the primary organ for perceiving signals in the soil from neighboring plants, root behavior may play an important role in soil-borne disease control. PRINCIPAL FINDINGS: In two years of field experiments, maize/soybean intercropping suppressed the occurrence of soybean red crown rot, a severe soil-borne disease caused by Cylindrocladium parasiticum (C. parasiticum. The suppressive effects decreased with increasing distance between intercropped plants under both low P and high P supply, suggesting that root interactions play a significant role independent of nutrient status. Further detailed quantitative studies revealed that the diversity and intensity of root interactions altered the expression of important soybean PR genes, as well as, the activity of corresponding enzymes in both P treatments. Furthermore, 5 phenolic acids were detected in root exudates of maize/soybean intercropped plants. Among these phenolic acids, cinnamic acid was released in significantly greater concentrations when intercropped maize with soybean compared to either crop grown in monoculture, and this spike in cinnamic acid was found dramatically constrain C. parasiticum growth in vitro. CONCLUSIONS: To the best of our knowledge, this study is the first report to demonstrate that intercropping with maize can promote resistance in soybean to red crown rot in a root-dependent manner. This supports the point that intercropping may be an efficient ecological strategy to control soil-borne plant disease and should be incorporated in sustainable agricultural management practices.

  11. PATHOGENICITY TESTS AND EVALUATION OF EFFICACY OF FUNGICIDES AGAINST RHIZOCTONIA BATATICOLA, THE CAUSAL AGENT OF DRY ROOT ROT OF CHICKPEA

    Directory of Open Access Journals (Sweden)

    G Amrutha Veena

    2014-03-01

    Full Text Available The pathogen was identified based on its mycelial and sclerotial characters and pathogenicity test was proved by soil inoculation method. Efficacy of two non systemic fungicides (copper oxychloride and captan, two systemic fungicides (hexaconazole and tebuconazole and one antifungal antibiotic validamycin each at different concentrations were tested against Rhizoctonia bataticola, incitant of dry root rot of chickpea under in vitro conditions. The fungicides copper oxychloride, captan, hexaconazole and tebuconazole were found to be highly effective (100% in inhibiting the mycelial growth of the highly virulent pathogen at all the concentrations tested.

  12. Effects of soil moisture on cotton root length density and yield under drip irrigation with plastic mulch in Aksu Oasis farmland

    Institute of Scientific and Technical Information of China (English)

    Yilihamu; Yimamu

    2010-01-01

    Effects of soil moisture on cotton root length density (total root length per unit soil volume) and yield under drip irrigation with plastic mulch were studied through field experiments. The results indicate that spatial distributions of root length density of cotton under various water treatments were basically similar. Horizontally, both root length densities of cotton in wide and narrow rows were similar, and higher than that between mulches. Vertically, root length density of cotton decreased with increasing soil depth. The distribution of root length density is different under different irrigation treatments. In conditions of over-irrigation, the root length density of cotton between mulches would increase. However, it would decrease in both the wide rows and narrow rows. The mean root length density of cotton increased with increasing irrigation water. Water stress caused the root length density to increase in lower soil layers. There is a significant correlation between root length density and yields of cotton at the flower-boll and wadding stages. The regression between irrigation amount and yield of cotton can be expressed as y = -0.0026x2+18.015x-24845 (R2 = 0.959). It showed that the irrigation volume of 3,464.4 m3/hm2 led to op-timal root length density. The yield of cotton was 6,360 .8 kg/hm2 under that amount of irrigation.

  13. Isolation screening and characterisation of local beneficial rhizobacteria based upon their ability to suppress the growth of Fusarium oxysporum f. sp. radicis-lycopersici and tomato foot and root rot

    Science.gov (United States)

    Tomato crown and root rot or tomato foot and root rot (TFRR) is caused by the phytopathogenic fungus Fusarium oxysporum f. sp. radicis-lycopersici (Forl). The disease occurs in both greenhouse and outdoor tomato cultivations and cannot be treated efficiently with the existing fungicides. We conducte...

  14. Ganoderma species, including new taxa associated with root rot of the iconic Jacaranda mimosifolia in Pretoria, South Africa.

    Science.gov (United States)

    Coetzee, Martin P A; Marincowitz, Seonju; Muthelo, Vuledzani G; Wingfield, Michael J

    2015-06-01

    Jacaranda mimosifolia trees have been progressively dying due to Ganoderma root and butt rot disease in Pretoria (the "City of Jacarandas") for many years. Ganoderma austroafricanum was described from these trees previously but this was based on a single collection. This study treats a substantially expanded collection of isolates of Ganoderma made from all dying trees where basidiomes were present in a Pretoria suburb. DNA sequences were obtained from the ITS and LSU region for the isolates and compared against sequences on GenBank. Phylogenetic analyses were used to compare sequences with those for other Ganoderma species. Based on sequence comparisons and morphological characters, two new Ganoderma species were discovered and these are described here as G. enigmaticum and G. destructans spp. nov. Interestingly, the previously described G. austroafricanum was not found, G. enigmaticum was found on only one Ceratonia siliqua tree and G. destructans was found on all other trees sampled. The latter species appears to be the primary cause of root rot of J. mimosifolia in the area sampled.

  15. Granular Nematicides as Adjuncts to Fumigants for Control of Cotton Root-knot Nematodes.

    Science.gov (United States)

    Jorgenson, E C

    1979-04-01

    Growth and yield of cotton were best with combinations of fumigants and organophosphate and carbamate nematicides. Organophosphates or carbamates used alone did not give season-long control of root-knot nematodes. Long-term control was poor because the temporary sublethal effects of these materials diminished soon enough lhat the nematodes could reproduce. The nematodes survived the treatments and a year of nonhost culture, and damaged a susceptible host crop 2 years after treatment. No such damage occurred in plots treated with fumigant, fumigant plus organophosphate, or fumigant plus carbamate. Treatment of seed and treatment of cotton, either in furrow at planting or sidedressing at midseason, with organophosphate and carbamate nematicides resulted in little or no yield increase, because nematode control was only minimal and temporary; or in a yield decrease, because the toxicity of the materials was manifested when nematode populations were low.

  16. iTRAQ-Based Quantitative Proteomic Analysis of Cotton Roots and Leaves Reveals Pathways Associated with Salt Stress.

    Science.gov (United States)

    Chen, Tingting; Zhang, Lei; Shang, Haihong; Liu, Shaodong; Peng, Jun; Gong, Wankui; Shi, Yuzhen; Zhang, Siping; Li, Junwen; Gong, Juwu; Ge, Qun; Liu, Aiying; Ma, Huijuan; Zhao, Xinhua; Yuan, Youlu

    2016-01-01

    Salinity is a major abiotic stress that affects plant growth and development. In this study, we performed a proteomic analysis of cotton roots and leaf tissue following exposure to saline stress. 611 and 1477 proteins were differentially expressed in the roots and leaves, respectively. In the roots, 259 (42%) proteins were up-regulated and 352 (58%) were down-regulated. In the leaves, 748 (51%) proteins were up-regulated and 729 (49%) were down-regulated. On the basis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, we concluded that the phenylalanine metabolism and starch and sucrose metabolism were active for energy homeostasis to cope with salt stress in cotton roots. Moreover, photosynthesis, pyruvate metabolism, glycolysis / gluconeogenesis, carbon fixation in photosynthetic organisms and phenylalanine metabolism were inhabited to reduce energy consumption. Characterization of the signaling pathways will help elucidate the mechanism activated by cotton in response to salt stress.

  17. Cotton (Gossypium hirsutum L.) boll rotting bacteria vectored by the brown stink bug, Euschistus servus (Say) (Hemiptera: Pentatomidea)

    Science.gov (United States)

    Determine the capacity of the brown stink bug (Euschistus servus) to transmit an infective Pantoea agglomerans into cotton (Gossypium hirsutum, L.) bolls. A laboratory colony of the brown stink bug (BSB) was maintained on fresh green beans. The P. agglomerans mutant strain Sc 1-R that holds rifamp...

  18. Relative Efficacy of On-Farm Weeds as Soil-Amendement for Managing Dry Root Rot of Clusterbean in an Arid Environment

    Directory of Open Access Journals (Sweden)

    R. Mawar

    2006-12-01

    Full Text Available The effectiveness of certain on-farm weeds as soil amendments was ascertained against Macrophomina phaseolina, a soil-borne pathogen causing dry root rot of crops grown under rainfed conditions in arid regions. Population changes in M. phaseolina were determined in soils amended separately with residues (1%, w:w of Aerva persica, Celosia argentea, Corchorus depressus, Euphorbia hirta, Heliotropium subulatum and Polycarpaea corymbosa, for a period of 90 days. Significant reductions by 90.4–100% in the population of M. phaseolina were achieved with all the weed residues except P. corymbosa. Celosia and Euphorbia residues completely eradicated viable propagules of M. phaseolina. A strong increase (44–61% in the population of antagonistic actinomycetes was also found in soil amended with Corchorus and Euphorbia. In field tests, soil amended (50 g m2 with Euphorbia, Aerva and Celosia residues significantly reduced dry root rot incidence on clusterbean and also reduced M. phaseolina propagules in the soil. However, dry root rot incidence in Polycarpaea-amended soil (5.8–24.6% was not significantly different from that in non-amended soil (4.3–25.3% in both years of the experiment. P. corymbosa also increased the number of propagules of M. phaseolina in the soil. The results demonstrate that dry root rot of rainfed-cultivated annual crops in arid land can be managed with certain weeds as a soil amendment.

  19. Efficacy of seed treatments in reducing seed and root rot of peas in the presence of metalaxyl-resistant Pythium, 2007

    Science.gov (United States)

    Five organic seed treatments and eighteen commercial seed treatments were evaluated in a commercial pea field (sandy loam soil) in Paterson, WA to manage seed and root rot of processed peas. The soil from the field site had a mean of 89 total Pythium colonies and 27 metalaxyl-resistant Pythium colo...

  20. Rapid and sensitive diagnoses of dry root rot pathogen of chickpea (Rhizoctonia bataticola (Taub.) Butler) using loop-mediated isothermal amplification assay.

    Science.gov (United States)

    Ghosh, Raju; Tarafdar, Avijit; Sharma, Mamta

    2017-02-20

    Dry root rot (DRR) caused by the fungus Rhizoctonia bataticola (Taub.) Butler, is an emerging disease in chickpea. The disease is often mistaken with other root rots like Fusarium wilt, collar rot and black root rot in chickpea. Therefore, its timely and specific detection is important. Current detection protocols are either based on mycological methods or on protocols involving DNA amplification by polymerase chain reaction (PCR). Here we report the rapid and specific detection of R. bataticola using loop-mediated isothermal amplification (LAMP) assay targeting fungal specific 5.8S rDNA sequence for visual detection of R. bataticola. The reaction was optimized at 63 °C for 75 min using minimum 10 fg of DNA. After adding SYBR Green I in LAMP products, the amplification was found to be highly specific in all the 94 isolates of R. bataticola collected from diverse geographical regions as well as DRR infected plants and sick soil. No reaction was found in other pathogenic fungi infecting chickpea (Fusarium oxysporum f. sp. ciceris, Rhizoctonia solani, Sclerotium rolfsii and Fusarium solani) and pigeonpea (Fusarium udum and Phytophthora cajani). The standardised LAMP assay with its simplicity, rapidity and specificity is very useful for the visual detection of this emerging disease in chickpea.

  1. The effect of temperature and rainfall on participation of the pathogens causing root and stem rot in spring barley (Hordeum vulgare L.

    Directory of Open Access Journals (Sweden)

    Barbara Łacicowa

    2013-12-01

    Full Text Available Field experiments conducted in the years 1990-1995 were localized at the Plaiit Cultivation Station, Ulhówek to repeat the cultivation of spring barley cultivars Roland and Lot. In conditions of monoculture, Bipolaris sorokiniana and Fusarium culmorum were of the foremost importance in causing root and stem rot. The proportion of infected plants did not increase with time. Depending on the period of vegetation and the cultivar, the percentage of seedlings with necrosis symptoms ranged from 6% to 53,5% and that of stem base rot from 14% to 59%. In the case of both cultivars. root and stem rot was especially intensive in the third successive season of vegetation, i, e,. in 1992. That season was characterized by warm and wet weather conditions. favourable for the infection of seedlings by B.sorokiniane during the period of six weeks after the sowing of grain. Bipolaris sorokiniana always had the greatest proportion in the infction of spring barley but not in the seasons distinguished by hot and dry weather conditions. On the other hand, during dry and hot weather conditions the only or the dominating fungus obtained from the infcted stem base after the heading of spring barley was F. culmorum. In conditions of monoculture, favourable for root and stem rot of spring barley, the temperature and rainfalls clearly distinguished the proportion of B. sorokiniana and F. culmorum in plant infection.

  2. Endophytic Bacteria Improve Plant Growth, Symbiotic Performance of Chickpea (Cicer arietinum L. and Induce Suppression of Root Rot Caused by Fusarium solani under Salt Stress

    Directory of Open Access Journals (Sweden)

    Dilfuza Egamberdieva

    2017-09-01

    Full Text Available Salinity causes disturbance in symbiotic performance of plants, and increases susceptibility of plants to soil-borne pathogens. Endophytic bacteria are an essential determinant of cross-tolerance to biotic and abiotic stresses in plants. The aim of this study was to isolate non–rhizobial endophytic bacteria from the root nodules of chickpea (Cicer arietinum L., and to assess their ability to improve plant growth and symbiotic performance, and to control root rot in chickpea under saline soil conditions. A total of 40 bacterial isolates from internal root tissues of chickpea grown in salinated soil were isolated. Four bacterial isolates, namely Bacillus cereus NUU1, Achromobacter xylosoxidans NUU2, Bacillus thuringiensis NUU3, and Bacillus subtilis NUU4 colonizing root tissue demonstrated plant beneficial traits and/or antagonistic activity against F. solani and thus were characterized in more detail. The strain B. subtilis NUU4 proved significant plant growth promotion capabilities, improved symbiotic performance of host plant with rhizobia, and promoted yield under saline soil as compared to untreated control plants under field conditions. A combined inoculation of chickpea with M. ciceri IC53 and B. subtilis NUU4 decreased H2O2 concentrations and increased proline contents compared to the un-inoculated plants indicating an alleviation of adverse effects of salt stress. Furthermore, the bacterial isolate was capable to reduce the infection rate of root rot in chickpea caused by F. solani. This is the first report of F. solani causing root rot of chickpea in a salinated soil of Uzbekistan. Our findings demonstrated that the endophytic B. subtilis strain NUU4 provides high potentials as a stimulator for plant growth and as biological control agent of chickpea root rot under saline soil conditions. These multiple relationships could provide promising practical approaches to increase the productivity of legumes under salt stress.

  3. Soil amendment with Aerva javanica (Burm. F. Juss. ex Schult. in the control of root rot fungi of cowpea [Vigna unguiculata (L. Walp.] and mung bean [Vigna radiata (L.

    Directory of Open Access Journals (Sweden)

    Naheed Ikram

    2012-10-01

    Full Text Available Root rot fungi cause severe losses of crop plants, so the present work was carried out to determine the effect of Aerva javanica parts powder on root infecting fungi of mung bean (Vigna radiata (L. and cowpea (Vigna unguiculata (L. Walp.. A. javanica parts (stem, leaves and flower were used as soil amendments at 0.1, 1 and 5% to check the effectiveness on growth parameters. All the plant parts showed a significant reduction in root rot fungi like Fusarium spp., Rhizoctonia solani Kuhn, and Macrophomina phaseolina (Tassi Goid. It was noted that germination percentage, fresh weight, leaf area and number of nodules were significantly higher and the inhibitory effect on root rot fungi increased when the soil was amended with A. javanica leaves at 1%. Thus, among all the treatments, A. javanica leaves at 1% were found to be the most effective against root rot fungi.

  4. Genotype and Planting Density Effects on Rooting Traits and Yield in Cotton (Gossypium hirsutum L.)

    Institute of Scientific and Technical Information of China (English)

    Li-Zhen Zhang; Bao-Guo Li; Gen-Tu Yan; Wopke van der Werf; JHJ Spiertz; Si-Ping Zhang

    2006-01-01

    Root density distribution of plants is a major indicator of competition between plants and determines resource capture from the soil. This experiment was conducted in 2005 at Anyang, located in the Yellow River region, Henan Province, China. Three cotton (Gossypium hirsutum L.) cultivars were chosen: hybrid Bt-cultivar CRI46, conventional Bt-cultivars CRI44 and CRI45. Six planting densities were designed, ranging from 1.5 to 12.0 plants/m2. Root parameters such as surface area, diameter and length were analyzed by using the DT-SCAN image analysis method. The root length density (RLD), root average diameter and root area index (RAI), root surface area per unit land area, were studied. The results showed that RLD and RAI differed between genotypes; hybrid CRI46 had significantly higher (P < 0.05) RLD and RAI values than conventional cultivars, especially under low planting densities, less than 3.0 plants/m2. The root area index (RAI) of hybrid CRI46 was 61% higher than of CRI44 and CRI45 at the flowering stage. The RLD and RAI were also significantly different (P= 0.000) between planting densities. The depth distribution of RAI showed that at increasing planting densities RAI was increasingly distributed in the soil layers below 50 cm. The RAI of hybrid CRI46 was for all planting densities, obviously higher than other cultivars during the flowering and boll stages. It was concluded that the hybrid had a strong advantage in root maintenance preventing premature senescence of roots. The root diameter of hybrid CRI46 had a genetically higher root diameter at planting densities lower than 6.0 plants/m2. Good associations were found between yield and RAI in different stages. The optimum planting density ranged from 4.50 plants/m2 to 6.75 plants/m2 for conventional cultivars and around 4.0-5.0 plants/m2 for hybrids.

  5. Isolation, characterization, and formulation of antagonistic bacteria for the management of seedlings damping-off and root rot disease of cucumber.

    Science.gov (United States)

    Khabbaz, Salah Eddin; Abbasi, Pervaiz A

    2014-01-01

    Antagonistic bacteria are common soil inhabitants with potential to be developed into biofungicides for the management of seedling damping-off, root rot, and other soil-borne diseases of various crops. In this study, antagonistic bacteria were isolated from a commercial potato field and screened for their growth inhibition of fungal and oomycete pathogens in laboratory tests. The biocontrol potential of the 3 most effective antagonistic bacteria from the in vitro tests was evaluated against seedling damping-off and root rot of cucumber caused by Pythium ultimum. Based on phenotypic characteristics, biochemical tests, and sequence analysis of 16S-23S rDNA gene, the 3 antagonistic bacteria were identified as Pseudomonas fluorescens (isolate 9A-14), Pseudomonas sp. (isolate 8D-45), and Bacillus subtilis (isolate 8B-1). All 3 bacteria promoted plant growth and suppressed Pythium damping-off and root rot of cucumber seedlings in growth-room assays. Both pre- and post-planting application of these bacteria to an infested peat mix significantly increased plant fresh masses by 113%-184% and percentage of healthy seedlings by 100%-290%, and decreased damping-off and root rot severity by 27%-50%. The peat and talc formulations of these antagonistic bacteria applied as seed or amendment treatments to the infested peat mix effectively controlled Pythium damping-off and root rot of cucumber seedlings and enhanced plant growth. The survival of all 3 antagonistic bacteria in peat and talc formulations decreased over time at room temperature, but the populations remained above 10(8) CFU/g during the 180-day storage period. The peat formulation of a mixture of 3 bacteria was the best seed treatment, significantly increasing the plant fresh masses by 245% as compared with the Pythium control, and by 61.4% as compared with the noninfested control. This study suggests that the indigenous bacteria from agricultural soils can be developed and formulated as biofungicides for minimizing

  6. INFLUENCE OF NPK AND LIME APLICATION ON ERVA-MATE GROWTH, ROOT-ROT SEVERITY AND SOIL FUNGI POPULATION1

    Directory of Open Access Journals (Sweden)

    Igor Poletto

    2011-09-01

    Full Text Available The present work evaluated the influence of the application of NPK and liming doses in the soil, on the growth of Erva-mate, the severity of rot-root and the fungi population of the soil. To do so, an experiment was installed at the green house, in the Forest Nursery of UFSM, using an experimental design completely randomized factorial 4x3x4 (Factor F: Fusarium spp. inoculation; Factor C: soil limestone; Factor A: NPK doses , totaling 48 treatments. The seedlings were cultivated in vases containing 2 kg of soil, classified as ‘Red-Yellow Argisoil’ (clay soil. At the end of the experiment was measured the stem diameter, height of the aerial part, leaves number, aerial dry biomass, root dry biomass and total dry biomass of the seedlings. Also, the soil was collected, from each treatment, for the chemical analysis and the counting of the fungi population. It was observed that the association among application of NPK and liming in the soil hampered the development of Erva-mate seedlings. The analysis of some variables suggests that the limestone absence provided greater resistance of seedlings to the attack of Fusarium spp. or the severity of Fusarium spp. was reduced in lower pH. The fungi population of the soil presented varied behavior depending on the applied treatments.

  7. In vitro and in vivo antagonism of actinomycetes isolated from Moroccan rhizospherical soils against Sclerotium rolfsii: a causal agent of root rot on sugar beet (Beta vulgaris L.).

    Science.gov (United States)

    Errakhi, R; Lebrihi, A; Barakate, M

    2009-08-01

    To evaluate the ability of the isolated actinomycetes to inhibit in vitro plant pathogenic fungi and the efficacy of promising antagonistic isolates to reduce in vivo the incidence of root rot induced by Sclerotium rolfsii on sugar beet. Actinomycetes isolated from rhizosphere soil of sugar beet were screened for antagonistic activity against a number of plant pathogens, including S. rolfsii. Ten actinomycetes out of 195 screened in vitro were strongly inhibitory to S. rolfsii. These isolates were subsequently tested for their ability to inhibit sclerotial germination and hyphal growth of S. roflsii. The most important inhibitions were obtained by the culture filtrate from the isolates J-2 and B-11, including 100% inhibition of sclerotial germination and 80% inhibition of hyphal growth. These two isolates (J-2 and B-11) were then screened for their ability to protect sugar beet against infection of S. rolfsii induced root rot in a pot trial. The treatment of S. rolfsii infested soil with a biomass and culture filtrate mixture of the selected antagonists reduced significantly (P beet. Isolate J-2 was most effective and allowed a high fresh weight of sugar beet roots to be obtained. Both antagonists J-2 and B-11 were classified as belonging to the genus Streptomyces species through morphological and chemical characteristics as well as 16S rDNA analysis. Streptomyces isolates J-2 and B-11 showed a potential for controlling root rot on sugar beet and could be useful in integrated control against diverse soil borne plant pathogens. This investigation showed the role, which actinomycete bacteria can play to control root rot caused by S. rolfsii, in the objective to reduce treatments with chemical fungicides.

  8. Integrated Management of Damping-off, Root and/or Stem Rot Diseases of Chickpea and Efficacy of the Suggested Formula

    Directory of Open Access Journals (Sweden)

    Montaser Fawzy ABDEL-MONAIM

    2011-08-01

    Full Text Available Eleven fungal isolates were isolated from naturally infected chickpea roots collected from different locations in New Valley Governorate (Egypt. The isolated fungi were purified and identified as Rhizoctonia solani (5 isolates, Fusarium solani (4 isolates and Sclerotinia sclerotiorum (2 isolates. The isolated fungi proved their pathogenicity on cv. Giza 3. Response of chickpea cvs. Giza 1, Giza 2, Giza 3, Giza 4, Giza 88, Giza 195, Giza 531 to infection by the tested fungi was significantly varied. Giza 1 was the most resistant one followed by Giza 531, while the other tested cvs. were highly susceptible. Seven biocontrol agents, namely Bacillus subtilis, B. megaterium, B. cereus, Trichoderma viride, T. harzianum, Aspergillus sp., Penicillium sp. isolated from chickpea rhizosphere, were tested for their antagonistic action against the tested pathogens. B. subtilis isolate BSM1, B. megaterium isolate TVM5, T. viride isolate TVM2 and T. harzianum isolate THM4 were the most antagonistic ones to the tested fungi in vitro, while the other isolates were moderate or weak antagonists. The most antagonistic isolates as well as the commercial biocide Rhizo-N were applied as seed treatment for controlling damping-off, root and/or stem rot diseases caused by the tested fungi under greenhouse conditions. The obtained data showed that all tested antagonistic isolates were able to cause significant reduction of damping-off, root and/or stem rot diseases in chickpea plants. T. viride (isolate TVM2 and B. megaterium (isolate BMM5 proved to be the most effective isolates for controlling the diseases. Under field condition, the obtained data indicated that all the tested antagonistic isolates significantly reduced damping-off, root and/or stem rot. T. viride (isolate TVM2 and B. megaterium (isolate BMM5 recorded the highest reduction of damping-off, root and/or stem rot in all sowing dates. Sowing of treated seeds with bioagents in first of November gave the

  9. Biocontrol traits of plant growth suppressive arbuscular mycorrhizal fungi against root rot in tomato caused by Pythium aphanidermatum

    DEFF Research Database (Denmark)

    Larsen, John; Graham, James H.; Cubero, Jaime

    2012-01-01

    Arbuscular mycorrhizal (AM) fungi known to cause plant growth depressions in tomato were examined for their biocontrol effects against root rot caused by Pythium aphanidermatum. The main hypothesis was that plant growth suppressive AM fungi would elicit a defence response in the host plant reducing...... Pythium root rot development. To test this hypothesis a fully factorial experiment was performed with AM fungi (Glomus intraradices, G. mosseae, G. claroideum or nonmycorrhizal), Pythium (± P. aphanidermatum) and harvest (7 and 14 days after pathogen inoculation (dapi)) as the main factors. Two weeks...... growth suppressions, but did not affect PR-1 gene expression or the phosphorous concentration in the host plant. Plants singly inoculated with P. aphanidermatum had an increased PR-1 expression and phosphorous concentration. Among the AM fungi included in the study only G. intraradices reduced...

  10. 丹参根腐病原菌的分离与鉴定%Isolation and identification of root rot pathogen of Salvia miltiorrhiza Bunge

    Institute of Scientific and Technical Information of China (English)

    袁孟娟; 藏香银; 韩军; 陈芳

    2015-01-01

    In order to further understand the variety and biology characteristics of the pathogens of Salvia miltiorrhiza Bunge root rot, one strain of fungi was isolated from the root rot samples of S.miltiorrhiza Bunge by tissue isolation.According to the pathogenicity test and the morphological observation of the pathogen, as well as molecular biological identification, it was identified as Fusarium solani.%为进一步了解丹参( Salvia miltiorrhiza Bunge)根腐病病原菌的种类及生物学特性,采用组织分离法从丹参根腐病样本中分离到1株真菌,经致病性测定、形态学观察和分子生物学鉴定,将其鉴定为腐皮镰刀菌( Fu-sarium solani )。

  11. Organic amendments conditions on the control of Fusarium crown and root rot of asparagus caused by three Fusarium spp

    Energy Technology Data Exchange (ETDEWEB)

    Borrego-Benjumea, A.I.; Melero-Vara, J.M.; Basallote-Ureba, M.J.

    2015-07-01

    Fusarium oxysporum (Fo), F. proliferatum (Fp) and F. solani (Fs) are causal agents associated with roots of asparagus affected by crown and root rot, a disease inflicting serious losses worldwide. The propagule viability of Fusarium spp. was determined on substrate artificially infested with Fo5, Fp3 or Fs2 isolates, amended with either poultry manure (PM), its pellet (PPM), or olive residue compost (ORC) and, thereafter, incubated at 30 or 35°C for different periods. Inoculum viability was significantly affected by these organic amendments (OAs) in combination with temperature and incubation period. The greatest reduction in viability of Fo5 and Fs2 occurred with PPM and loss of viability achieved was higher at 35°C than at 30ºC, and longer incubation period (45 days). However, the viability of Fp3 did not decrease greatly in most of the treatments, as compared to the infested and un-amended control, when incubated at 30ºC. After incubation, seedlings of asparagus Grande´ were transplanted into pots containing substrates infested with the different species of Fusarium. After three months in greenhouse, symptoms severity in roots showed highly significant decreases, but Fp3 caused lower severity than Fo5 and Fs2. Severity reduction was particularly high at 30ºC (by 15 days incubation for Fs2 and by 30-45 days for Fo5), after PPM treatment, as well as PM-2% for Fo5 and Fs2 incubated during 30 and 45 days at both temperatures, and with ORC (15-30 days incubation). Moreover, assessment of plants fresh weight showed significantly high increases in Fo5 and Fs2, with some rates of the three OAs tested, depending on incubat. (Author)

  12. Organic amendments conditions on the control of Fusarium crown and root rot of asparagus caused by three Fusarium spp.

    Directory of Open Access Journals (Sweden)

    Ana I. Borrego-Benjumea

    2015-12-01

    Full Text Available Fusarium oxysporum (Fo, F. proliferatum (Fp and F. solani (Fs are causal agents associated with roots of asparagus affected by crown and root rot, a disease inflicting serious losses worldwide. The propagule viability of Fusarium spp. was determined on substrate artificially infested with Fo5, Fp3 or Fs2 isolates, amended with either poultry manure (PM, its pellet (PPM, or olive residue compost (ORC and, thereafter, incubated at 30 or 35°C for different periods. Inoculum viability was significantly affected by these organic amendments (OAs in combination with temperature and incubation period. The greatest reduction in viability of Fo5 and Fs2 occurred with PPM and loss of viability achieved was higher at 35°C than at 30ºC, and longer incubation period (45 days. However, the viability of Fp3 did not decrease greatly in most of the treatments, as compared to the infested and un-amended control, when incubated at 30ºC. After incubation, seedlings of asparagus `Grande´ were transplanted into pots containing substrates infested with the different species of Fusarium. After three months in greenhouse, symptoms severity in roots showed highly significant decreases, but Fp3 caused lower severity than Fo5 and Fs2. Severity reduction was particularly high at 30ºC (by 15 days incubation for Fs2 and by 30-45 days for Fo5, after PPM treatment, as well as PM-2% for Fo5 and Fs2 incubated during 30 and 45 days at both temperatures, and with ORC (15-30 days incubation. Moreover, assessment of plants fresh weight showed significantly high increases in Fo5 and Fs2, with some rates of the three OAs tested, depending on incubation period and temperature.

  13. Biocontrol bacteria selected by a direct plant protection strategy against avocado white root rot show antagonism as a prevalent trait.

    Science.gov (United States)

    González-Sánchez, M Á; Pérez-Jiménez, R M; Pliego, C; Ramos, C; de Vicente, A; Cazorla, F M

    2010-07-01

    This study was undertaken to study bacterial strains obtained directly for their efficient direct control of the avocado white root rot, thus avoiding prescreening by any other possible mechanism of biocontrol which could bias the selection. A collection of 330 bacterial isolates was obtained from the roots and soil of healthy avocado trees. One hundred and forty-three representative bacterial isolates were tested in an avocado/Rosellinia test system, resulting in 22 presumptive protective strains, all of them identified mainly as Pseudomonas and Bacillus species. These 22 candidate strains were screened in a more accurate biocontrol trial, confirming protection of some strains (4 out of the 22). Analyses of the potential bacterial traits involved in the biocontrol activity suggest that different traits could act jointly in the final biocontrol response, but any of these traits were neither sufficient nor generalized for all the active bacteria. All the protective strains selected were antagonistic against some fungal root pathogens. Diverse bacteria with biocontrol activity could be obtained by a direct plant protection strategy of selection. All the biocontrol strains finally selected in this work were antagonistic, showing that antagonism is a prevalent trait in the biocontrol bacteria selected by a direct plant protection strategy. This is the first report on the isolation of biocontrol bacterial strains using direct plant protection strategy in the system avocado/Rosellinia. Characterization of selected biocontrol bacterial strains obtained by a direct plant protection strategy showed that antagonism is a prevalent trait in the selected strains in this experimental system. This suggests that antagonism could be used as useful strategy to select biocontrol strains. © 2009 The Authors. Journal compilation © 2009 The Society for Applied Microbiology.

  14. Plant growth-promoting rhizobacterial strain-mediated induced systemic resistance in tea (Camellia sinensis (L.) O. Kuntze) through defense-related enzymes against brown root rot and charcoal stump rot.

    Science.gov (United States)

    Mishra, A K; Morang, P; Deka, M; Nishanth Kumar, S; Dileep Kumar, B S

    2014-09-01

    Induction of systemic resistance in host plants through microbes and their bioactive metabolites are attaining popularity in modern agricultural practices. In this regard, individual application of two strains of Pseudomonas, RRLJ 134 and RRLJ 04, exhibited development of induced systemic resistance in tea plants against brown root rot and charcoal stump rot under split root experiments. The experimental findings also confirmed that the cuttings treated with fungal test pathogen and plant growth-promoting rhizobacteria (PGPR) strains survived longer as compared with pathogen-alone-treated cuttings. The enzyme level studies revealed that the presence of PGPR strains reduced the viscosity loss of cellulose and pectin by both the pathogens to a significant level. The activity of defense-related enzymes like L-phenylalanine ammonia lyase, peroxidase, and polyphenol oxidase were also recorded higher in tea cuttings treated with PGPR strains in presence of pathogen. Crude bioactive metabolites isolated from these strains also showed in vitro antagonism against the test pathogens besides reducing the number of diseased plants under gnotobiotic conditions. These findings confirm the utilization of these two strains for induction of systemic resistance against two major root diseases in tea plants under plantation conditions.

  15. Identification and ControI of Root Rot in Wheat%小麦根腐病的识别与防治

    Institute of Scientific and Technical Information of China (English)

    潘万明

    2015-01-01

    Infection cycle and occur-rence regularity of two root rot in wheat (wheat common root rot and wheat Bipo-laris leaf spot and root rot) were intro-duced,and damage symptom and identifi-cation features of each disease were put forward.Then it proposed the correspond-ing control measures from two aspects including agricultural measures and chemical measures.The study aimed to reduce damages of diseases and improve yield and quality of wheat.%介绍了小麦2种常见根腐病———小麦根腐病和小麦蠕孢叶斑根腐病的侵染循环和发生规律,指出各病害的危害症状及识别特征,并从农业防治、化学防治等方面提出了相应的防治措施。为减轻病害危害,提高小麦的产量和品质提供了一定的依据。

  16. Differential responses of vanilla accessions to root rot and colonization by Fusarium oxysporum f. sp. radicis-vanillae.

    Directory of Open Access Journals (Sweden)

    Sayuj eKoyyappurath

    2015-12-01

    Full Text Available Root and stem rot (RSR disease caused by Fusarium oxysporum f. sp. radicis-vanillae (Forv is the most damaging disease of vanilla (Vanilla planifolia and V. ×tahitensis, Orchidaceae. Breeding programs aimed at developing resistant vanilla varieties are hampered by the scarcity of sources of resistance to RSR and insufficient knowledge about the histopathology of Forv. In this work we have i identified new genetic resources resistant to RSR including V. planifolia inbreds and vanilla relatives, ii thoroughly described the colonization pattern of Forv into selected vanilla accessions, confirming its necrotic non-vascular behavior in roots, and iii evidenced the key role played by hypodermis, and particularly lignin deposition onto hypodermal cell walls, for resistance to Forv in two highly resistant vanilla accessions.Two hundred and fifty-four vanilla accessions were evaluated in the field under natural conditions of infection and in controlled conditions using in-vitro plants root-dip inoculated by the highly pathogenic isolate Fo072. For the 26 accessions evaluated in both conditions, a high correlation was observed between field evaluation and in-vitro assay.The root infection process and plant response of one susceptible and two resistant accessions challenged with Fo072 were studied using wide field and multiphoton microscopy. In susceptible V. planifolia, hyphae penetrated directly into the rhizodermis in the hairy root region then invaded the cortex through the passage cells where it induced plasmolysis, but never reached the vascular region. In the case of the resistant accessions, the penetration was stopped at the hypodermal layer. Anatomical and histochemical observations coupled with spectral analysis of the hypodermis suggested the role of lignin deposition in the resistance to Forv. The thickness of lignin constitutively deposited onto outer cell walls of hypodermis was highly correlated with the level of resistance for 21

  17. Abscisic acid in salt stress predisposition to phytophthora root and crown rot in tomato and chrysanthemum.

    Science.gov (United States)

    Dileo, Matthew V; Pye, Matthew F; Roubtsova, Tatiana V; Duniway, John M; Macdonald, James D; Rizzo, David M; Bostock, Richard M

    2010-09-01

    Plants respond to changes in the environment with complex signaling networks, often under control of phytohormones that generate positive and negative crosstalk among downstream effectors of the response. Accordingly, brief dehydration stresses such as salinity and water deficit, which induce a rapid and transient systemic increase in levels of abscisic acid (ABA), can influence disease response pathways. ABA has been associated with susceptibility of plants to bacteria, fungi, and oomycetes but relatively little attention has been directed at its role in abiotic stress predisposition to root pathogens. This study examines the impact of brief salinity stress on infection of tomato and chrysanthemum roots by Phytophthora spp. Roots of plants in hydroponic culture exposed to a brief episode of salt (sodium chloride) stress prior to or after inoculation were severely diseased relative to nonstressed plants. Tomato roots remained in a predisposed state up to 24 h following removal from the stress. An increase in root ABA levels in tomato preceded or temporally paralleled the onset of stress-induced susceptibility, with levels declining in roots prior to recovery from the predisposed state. Exogenous ABA could substitute for salt stress and significantly enhanced pathogen colonization and disease development. ABA-deficient tomato mutants lacked the predisposition response, which could be restored by complementation of the mutant with exogenous ABA. In contrast, ethylene, which exacerbates disease symptoms in some host-parasite interactions, did not appear to contribute to the predisposition response. Thus, several lines of evidence support ABA as a critical and dominant factor in the salinity-induced predisposition to Phytophthora spp. infection.

  18. Genetic Differentiation and Spatial Structure of Phellinus noxius, the Causal Agent of Brown Root Rot of Woody Plants in Japan.

    Directory of Open Access Journals (Sweden)

    Mitsuteru Akiba

    Full Text Available Phellinus noxius is a pathogenic fungus that causes brown root rot disease in a variety of tree species. This fungus is distributed in tropical and sub-tropical regions of Southeast and East Asia, Oceania, Australia, Central America and Africa. In Japan, it was first discovered on Ishigaki Island in Okinawa Prefecture in 1988; since then, it has been found on several of the Ryukyu Islands. Recently, this fungus was identified from the Ogasawara (Bonin Islands, where it has killed trees, including rare endemic tree species. For effective control or quarantine methods, it is important to clarify whether the Japanese populations of P. noxius are indigenous to the area or if they have been introduced from other areas. We developed 20 microsatellite markers from genome assembly of P. noxius and genotyped 128 isolates from 12 of the Ryukyu Islands and 3 of the Ogasawara Islands. All isolates had unique genotypes, indicating that basidiospore infection is a primary dissemination method for the formation of new disease foci. Genetic structure analyses strongly supported genetic differentiation between the Ryukyu populations and the Ogasawara populations of P. noxius. High polymorphism of microsatellite loci suggests that Japanese populations are indigenous or were introduced a very long time ago. We discuss differences in invasion patterns between the Ryukyu Islands and the Ogasawara Islands.

  19. Mycofumigation with Oxyporus latemarginatus EF069 for control of postharvest apple decay and Rhizoctonia root rot on moth orchid.

    Science.gov (United States)

    Lee, S O; Kim, H Y; Choi, G J; Lee, H B; Jang, K S; Choi, Y H; Kim, J-C

    2009-04-01

    To characterize the volatile antifungal compound produced by Oxyporus latemarginatus EF069 and to examine in vitro and in vivo fumigation activity of the fungus. An antifungal volatile-producing strain, O. latemarginatus EF069 inhibited the mycelial growth of Alternaria alternata, Botrytis cinerea, Colletotrichum gloeosporioides, Fusarium oxysporum f. sp. lycopersici, and Rhizoctonia solani by mycofumigation. An antifungal volatile compound was isolated from the hexane extract of wheat bran-rice hull cultures of O. latemarginatus EF069 by repeated silica gel column chromatography and identified as 5-pentyl-2-furaldehyde (PTF). The purified PTF inhibited mycelial growth of R. solani in a dose-dependent manner. The mycofumigation with solid cultures of EF069 also reduced effectively the development of postharvest apple decay caused by B. cinerea and Rhizoctonia root rot of moth orchid caused by R. solani. Oxyporus latemarginatus EF069 showed in vitro and in vivo fumigation activity against plant pathogenic fungi by producing 5-pentyl-2-furaldehyde. Oxyporus latemarginatus EF069 producing an antifungal volatile compound may be used as a biofumigant for the control of fungal plant diseases.

  20. Genetic Differentiation and Spatial Structure of Phellinus noxius, the Causal Agent of Brown Root Rot of Woody Plants in Japan.

    Science.gov (United States)

    Akiba, Mitsuteru; Ota, Yuko; Tsai, Isheng J; Hattori, Tsutomu; Sahashi, Norio; Kikuchi, Taisei

    2015-01-01

    Phellinus noxius is a pathogenic fungus that causes brown root rot disease in a variety of tree species. This fungus is distributed in tropical and sub-tropical regions of Southeast and East Asia, Oceania, Australia, Central America and Africa. In Japan, it was first discovered on Ishigaki Island in Okinawa Prefecture in 1988; since then, it has been found on several of the Ryukyu Islands. Recently, this fungus was identified from the Ogasawara (Bonin) Islands, where it has killed trees, including rare endemic tree species. For effective control or quarantine methods, it is important to clarify whether the Japanese populations of P. noxius are indigenous to the area or if they have been introduced from other areas. We developed 20 microsatellite markers from genome assembly of P. noxius and genotyped 128 isolates from 12 of the Ryukyu Islands and 3 of the Ogasawara Islands. All isolates had unique genotypes, indicating that basidiospore infection is a primary dissemination method for the formation of new disease foci. Genetic structure analyses strongly supported genetic differentiation between the Ryukyu populations and the Ogasawara populations of P. noxius. High polymorphism of microsatellite loci suggests that Japanese populations are indigenous or were introduced a very long time ago. We discuss differences in invasion patterns between the Ryukyu Islands and the Ogasawara Islands.

  1. Calonectria spp. causing leaf spot, crown and root rot of ornamental plants in Tunisia

    NARCIS (Netherlands)

    Lombard, L.; Polizzi, G.; Guarnaccia, V.; Vitale, A.; Crous, P.W.

    2012-01-01

    Calonectria spp. are important pathogens of ornamental plants in nurseries, especially in the Northern Hemisphere. They are commonly associated with a wide range of disease symptoms of roots, leaves and shoots. During a recent survey in Tunisia, a number of Calonectria spp. were isolated from tissue

  2. Calonectria spp. causing leaf spot, crown and root rot of ornamental plants in Tunisia

    NARCIS (Netherlands)

    Lombard, L.; Polizzi, G.; Guarnaccia, V.; Vitale, A.; Crous, P.W.

    2011-01-01

    Calonectria spp. are important pathogens of ornamental plants in nurseries, especially in the Northern Hemisphere. They are commonly associated with a wide range of disease symptoms of roots, leaves and shoots. During a recent survey in Tunisia, a number of Calonectria spp. were isolated from tissue

  3. First report of root rot caused by Phytopythium helicoides on pistachio rootstock in California

    Science.gov (United States)

    We examined pathogenicity of Phytopythium helicoides on UCB-1 rootstock to investigate its role in root disease and collapse observed on potted pistachio plants. Approximately 25 potted 2-year-old pistachio rootstock trees in a Kern County, CA, research plot maintained outdoors and irrigated to cont...

  4. Biocontrol of tomato foot and root rot by Pseudomonas bacteria in stonewool

    NARCIS (Netherlands)

    Validov, Shamil

    2007-01-01

    The research described in this thesis shows that the enrichment technique based on competitive root tip colonization allows the isolation of bacteria which can protect plants from TFRR through the mechanism competition for nutrients (and niches). The efficacy of biocontrol of one of these strains,

  5. Control of the root-rot and root-knot disease complex by Pseudomonas aeruginosa: impact of bacterial rhizosphere colonization

    Directory of Open Access Journals (Sweden)

    I. A. Siddiqui

    2013-12-01

    Full Text Available The potential of 3 Pseudomonas aeriuginosa strains as biocontrol agents of rootinfecting fungi Macrophomina phaseolina, Fusarium solani and Rhizoctonia solani and the root-knot nematode Meloidogyne javanica was tested on chili and uridbean under greenhouse conditions. All the three strains significantly reduced nematode populations in soil, invasion, multiplication and gall formation due to M.javanica. Root infection by fungi was also effectively suppressed following P.aeruginosa application. Bacterial antagonists exhibited better biocontrol and growth promoting activity in 15-day-old plants than did those harvested at 30 or 45 days. Population of the bacterium in the rhizosphere declined rapidly after 15 days of nematode inoculation. Strain Pa-5 showed maximum nodulation in 15-day-old samplings while strain Pa-7 showed highest number of nodules in 30 and 45-day-old uridbean plants.

  6. Bipolaris sorokiniana (teleomorph Cochliobolus Sativus: Causer of barley leaf lesions and root rot in Macedonia

    Directory of Open Access Journals (Sweden)

    Karov Ilija K.

    2009-01-01

    Full Text Available Diseased barley plants (Hordeum vulgare, were noticed in the area of Kumanovo, Bitola, Probistip, Skopje and Kocani, at the beginning of March, 2006. Our investigations were carried out in the period from 2006 to 2009. The plants were highly diseased, probably in the stage of germination, dwarfed with necrotic leaves and with poorly developed root. A rotten root collar was noticed notice in some plants, which could be easily pulled out from the soil. Plants infected in a later developing stage became yellow from the top of the leaf, and many brown-olive, oval shape lesions were noticed. Conidia of Bipolaris sorokiniana (Sacc. Shoen., were isolated from symptomatic lesions. Pseudothecia with asci and ascospores from teleomorph Cochliobolus sativus, were found on the barley straw in the same field the previous year.

  7. Functional divergence of GhCFE5 homoeologs revealed in cotton fiber and Arabidopsis root cell development.

    Science.gov (United States)

    Lv, Fenni; Li, Peng; Zhang, Rui; Li, Nina; Guo, Wangzhen

    2016-04-01

    In GhCFE5 homoeologs, GhCFE5D interacted with more actin homologs and stronger interaction activity than GhCFE5A. GhCFE5D - but not GhCFE5A -overexpression severely disrupted actin cytoskeleton organization and significantly suppressed cell elongation. Homoeologous genes are common in polyploid plants; however, their functional divergence is poorly elucidated. Allotetraploid Upland cotton (Gossypium hirsutum, AADD) is the most widely cultivated cotton; accounting for more than 90 % of the world's cotton production. Here, we characterized GhCFE5A and GhCFE5D homoeologs from G. hirsutum acc TM-1. GhCFE5 homoeologs are expressed preferentially in fiber cells; and a significantly greater accumulation of GhCFE5A mRNA than GhCFE5D mRNA was found in all tested tissues. Overexpression of GhCFE5D but not GhCFE5A seriously inhibits the Arabidopsis hypocotyl and root cell elongation. Yeast two-hybrid assay and bimolecular fluorescence complementation (BiFC) analysis showed that compared with GhCFE5A, GhCFE5D interacts with more actin homologs and has a stronger interaction activity both from Arabidopsis and Upland cotton. Interestingly, subcellular localization showed that GhCFE5 resides on the cortical endoplasmic reticulum (ER) network and is colocalized with actin cables. The interaction activities between GhCFE5 homoeologs and actin differ in their effects on F-actin structure in transgenic Arabidopsis root cells. The F-actin changed direction from vertical to lateral, and the actin cytoskeleton organization was severely disrupted in GhCFE5D-overexpressing root cells. These data support the functional divergence of GhCFE5 homoeologs in the actin cytoskeleton structure and cell elongation, implying an important role for GhCFE5 in the evolution and selection of cotton fiber.

  8. Tobacco leaf spot and root rot caused by Rhizoctonia solani Kühn.

    Science.gov (United States)

    Gonzalez, Marleny; Pujol, Merardo; Metraux, Jean-Pierre; Gonzalez-Garcia, Vicente; Bolton, Melvin D; Borrás-Hidalgo, Orlando

    2011-04-01

    Rhizoctonia solani Kühn is a soil-borne fungal pathogen that causes disease in a wide range of plants worldwide. Strains of the fungus are traditionally grouped into genetically isolated anastomosis groups (AGs) based on hyphal anastomosis reactions. This article summarizes aspects related to the infection process, colonization of the host and molecular mechanisms employed by tobacco plants in resistance against R. solani diseases. Teleomorph: Thanatephorus cucumeris (Frank) Donk; anamorph: Rhizoctonia solani Kühn; Kingdom Fungi; Phylum Basidiomycota; Class Agaricomycetes; Order Cantharellales; Family Ceratobasidiaceae; genus Thanatephorus. Somatic hyphae in culture and hyphae colonizing a substrate or host are first hyaline, then buff to dark brown in colour when aging. Hyphae tend to form at right angles at branching points that are usually constricted. Cells lack clamp connections, but possess a complex dolipore septum with continuous parenthesomes and are multinucleate. Hyphae are variable in size, ranging from 3 to 17 µm in diameter. Although the fungus does not produce any conidial structure, ellipsoid to globose, barrel-shaped cells, named monilioid cells, 10-20 µm wide, can be produced in chains and can give rise to sclerotia. Sclerotia are irregularly shaped, up to 8-10 mm in diameter and light to dark brown in colour. Symptoms in tobacco depend on AG as well as on the tissue being colonized. Rhizoctonia solani AG-2-2 and AG-3 infect tobacco seedlings and cause damping off and stem rot. Rhizoctonia solani AG-3 causes 'sore shin' and 'target spot' in mature tobacco plants. In general, water-soaked lesions start on leaves and extend up the stem. Stem lesions vary in colour from brown to black. During late stages, diseased leaves are easily separated from the plant because of severe wilting. In seed beds, disease areas are typically in the form of circular to irregular patches of poorly growing, yellowish and/or stunted seedlings. Knowledge is scarce

  9. [Effects of water storage in deeper soil layers on the root growth, root distribution and economic yield of cotton in arid area with drip irrigation under mulch].

    Science.gov (United States)

    Luo, Hong-Hai; Zhang, Hong-Zhi; Zhang, Ya-Li; Zhang, Wang-Feng

    2012-02-01

    Taking cotton cultivar Xinluzao 13 as test material, a soil column culture expenment was conducted to study the effects of water storage in deeper (> 60 cm) soil layer on the root growth and its relations with the aboveground growth of the cultivar in arid area with drip irrigation under mulch. Two levels of water storage in 60-120 cm soil layer were installed, i. e., well-watered and no watering, and for each, the moisture content in 0-40 cm soil layer during growth period was controlled at two levels, i.e., 70% and 55% of field capacity. It was observed that the total root mass density of the cultivar and its root length density and root activity in 40-120 cm soil layer had significant positive correlations with the aboveground dry mass. When the moisture content in 0-40 cm soil layer during growth season was controlled at 70% of field capacity, the total root mass density under well-watered and no watering had less difference, but the root length density and root activity in 40-120 cm soil layer under well-watered condition increased, which enhanced the water consumption in deeper soil layer, increased the aboveground dry mass, and finally, led to an increased economic yield and higher water use efficiency. When the moisture content in 0-40 cm soil layer during growth season was controlled at 55% of field capacity and the deeper soil layer was well-watered, the root/shoot ratio and root length density in 40-120 cm soil layer and the root activity in 80-120 cm soil layer were higher, the water consumption in deeper soil layer increased, but it was still failed to adequately compensate for the negative effects of water deficit during growth season on the impaired growth of roots and aboveground parts, leading to a significant decrease in the economic yield, as compared with that at 70% of field capacity. Overall, sufficient water storage in deeper soil layer and a sustained soil moisture level of 65% -75% of field capacity during growth period could promote the

  10. Molecular variability among isolates of Fusarium oxysporum associated with root rot disease of Agave tequilana.

    Science.gov (United States)

    Vega-Ramos, Karla L; Uvalle-Bueno, J Xavier; Gómez-Leyva, Juan F

    2013-04-01

    In this study, 115 isolates of Fusarium oxysporum from roots of Agave tequilana Weber cv azul plants and soil in commercial plantations in western Mexico were characterized using morphological and molecular methods. Genetic analyses of monosporic isolates included restriction enzyme analysis of rDNA (ARDRA) using HaeIII and HinfI, and genetic diversity was determined using Box-PCR molecular markers. Box-PCR analysis generated 14 groups. The groups correlated highly with the geographic location of the isolate and sample type. These results demonstrate the usefulness of ARDRA and Box-PCR techniques in the molecular characterization of the Fusarium genus for the discrimination of pathogenic isolates.

  11. CHANGES IN THE BIOCHEMICAL CONSTITUENTS OF CARROT ROOTS DUE TO BACTERIAL SOFT ROT

    Directory of Open Access Journals (Sweden)

    V. K. Parthiban

    2013-03-01

    Full Text Available Carrot is a rich source of nutrients. The carrot contains carotene and lycopene, which gives bright color to the roots. The quality of the carrots was assessed based on the carotene, lycopene and other biochemical constituents like sugars, starch and protein. To study the effect of various isolates of the Erwinia carotovora var. carotovora on the above biochemical constituents, the pathogens were inoculated and the contents were analyzed separately at 1, 2, 3, 4, 5 days after inoculation. The contents of β-carotene increased significantly due to all the three isolates of the pathogen and the Coimbatore isolate recorded highest of 36.03 per cent. A same trend was also observed in the lycopene content with 93.55 per cent increase over control. The contents of total and reducing sugars were found to significantly increase due to inoculation with the pathogen. The starch content showed a decreasing trend in all the isolates tested. The maximum reduction of 62.98 per cent was observed in the roots inoculated with Coimbatore isolate.

  12. Comparison of Producing Enzyme Ability of Three White Rot Fungus in Cotton Straw%棉秸秆上3个白腐真菌菌系的产酶能力比较

    Institute of Scientific and Technical Information of China (English)

    江本利; 路曦结; 何团结; 朱加保; 叶泗洪; 添长久

    2012-01-01

    采用PDA—RB亮蓝平板和PDA—Bavendamm平板对从腐烂棉花秸秆上获得的3个白腐真菌菌系进行显色试验,单菌系与组合菌系同时比较。结果表明:3个菌系都具有产木质素降解酶的能力,且对3种主要酶种锰过氧化物酶(MnP)、木质素过氧化物酶(LiP)和漆酶(Lac)的测定显示,3个菌系相互之间协同作用大于拮抗作用,其中糙皮侧耳菌Z1单菌系及其组合菌系产酶能力均较强。%Colorful reactions of 3 white rot fungus strains in cotton rot straw were studied through PDA - RB blue plate and PDA - Bavendamm plate separately, and single strain and combined fungus strains were compared at the same time. It was proved that 3 white rot fungus strain could all produce lignin - degrading enzymes, among them pleurotus ostreatus Z1 and its combined fungus strains had more stronger ablity of production enzymes. Synergistic effect was stronger than antagonistic effect among 3 white rot fungus strains through tests of 3 main enzymes of Manganese peroxidase (MnP), Lignin peroxidase (LIP) and Laccase (Lac)

  13. Improvement of Biocontrol of Damping-off and Root Rot/Wilt of Faba Bean by Salicylic Acid and Hydrogen Peroxide.

    Science.gov (United States)

    Abdel-Monaim, Montaser Fawzy

    2013-03-01

    Rhizoctonia solani, Fusarium solani, F. oxysporum, and Macrophomina phaseolina were found to be associated with root rott and wilt symptoms of faba bean plants collected from different fieldes in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40) causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogenicity tests. Biocontrol agents (Trichoderma viride and Bacillus megaterium) and chemical inducers (salicylic acid [SA] and hydrogen peroxide) individually or in combination were examined for biological control of damping-off and root rot/wilt and growth promoting of faba bean plants in vitro and in vivo. Both antagonistic biocontrol agents and chemical inducers either individually or in combination inhibited growth of the tested pathogenic fungi. Biocontrol agents combined with chemical inducers recorded the highest inhibited growth especially in case SA + T. viride and SA + B. megaterium. Under green house and field conditions, all treatments significantly reduced damping-off and root rot/wilt severity and increased of survival plants. Also, these treatments increased fresh and weights of the survival plants in pots compared with control. The combination between biocontrol agents and chemical inducers were more effective than used of them individually and SA + T. viride was the best treatment in this respect. Also, under field conditions, all these treatments significantly increased growth parameters (plant height and number of branches per plant) and yield components (number of pods per plant and number of seeds per plant, weight of 100 seeds and total yield per feddan) and protein content in both seasons (2010~2011 and 2011~2012). Faba bean seeds soaked in SA + T. viride and SA + B. megaterium were recorded the highest growth parameters and yield components. Generally, the

  14. Effects of non-uniform root zone salinity on water use, Na+ recirculation, and Na+ and H+ flux in cotton.

    Science.gov (United States)

    Kong, Xiangqiang; Luo, Zhen; Dong, Hezhong; Eneji, A Egrinya; Li, Weijiang

    2012-03-01

    A new split-root system was established through grafting to study cotton response to non-uniform salinity. Each root half was treated with either uniform (100/100 mM) or non-uniform NaCl concentrations (0/200 and 50/150 mM). In contrast to uniform control, non-uniform salinity treatment improved plant growth and water use, with more water absorbed from the non- and low salinity side. Non-uniform treatments decreased Na(+) concentrations in leaves. The [Na(+)] in the '0' side roots of the 0/200 treatment was significantly higher than that in either side of the 0/0 control, but greatly decreased when the '0' side phloem was girdled, suggesting that the increased [Na(+)] in the '0' side roots was possibly due to transportation of foliar Na(+) to roots through phloem. Plants under non-uniform salinity extruded more Na(+) from the root than those under uniform salinity. Root Na(+) efflux in the low salinity side was greatly enhanced by the higher salinity side. NaCl-induced Na(+) efflux and H(+) influx were inhibited by amiloride and sodium orthovanadate, suggesting that root Na(+) extrusion was probably due to active Na(+)/H(+) antiport across the plasma membrane. Improved plant growth under non-uniform salinity was thus attributed to increased water use, reduced leaf Na(+) concentration, transport of excessive foliar Na(+) to the low salinity side, and enhanced Na(+) efflux from the low salinity root.

  15. Disease Investigation and Identification of the Pathogens Causing Root Rot of Tussilago farfaral%款冬花根腐病的发病情况与病原鉴定

    Institute of Scientific and Technical Information of China (English)

    张爱香; 马海莲; 李雪萍; 仝在利; 李世东; 王晓涛

    2011-01-01

    为找出引起款冬花根腐病的主要病原,对其综合防治提供参考依据,通过田间调查款冬花根腐病的症状以及室内病原物的分离、培养、纯化、回接试验.结果表明:款冬花根腐病的症状主要是萎蔫和根腐,引起根腐病的病原主要是立枯丝核菌(Rhizoctonia solani)、灰葡萄孢菌(Botrytis cinerea)、尖孢镰孢菌(Fusarium oxysporum Schlecht).%Symptom of Tussilago far faral root rot was investigated in the field and pathogens of Tussilago farfaral root rot was isolated, cultured, purified and re-inoculated in the laboratory to find out the main pathogens causing root rot of Tussilago farfaral and provide a reference for its comprehensive control. The results showed that the symptoms of the disease were expressed as wilt and root rot. Rhizoctonia solani, Botrytis cinerea and Fusarium oxysporum were the major pathogens of Tussilago far faral root rot.

  16. 麻疯树根腐病的病原鉴定%Identification of the Causal Agent of Root Rot Disease of Jatropha curcas L.in Luodian County

    Institute of Scientific and Technical Information of China (English)

    吴跃开; 欧国腾; 朱秀娥; 余金勇

    2011-01-01

    [Objective] The aim was to identify the causal agent of root rot disease of Jatropha curcas L. In Luodian County. [ Method ] Typical root rot samples were collected from different planting areas of Jatropha curcas L. In Luodian County, and then pathogens of the root rot samples were isolated, cultured, made a pathogenic test and observed under the microscope. [Result] The causal agent of root rot disease of Jatropha curcas L. Was Fusarium solani ( Martius) Appel & Wollenweber. [ Conclusion] The research provides reference for the effective prevention and control of root rot disease of Jatropha curcas L. In Luodian County.%[目的]鉴定麻疯树根腐病的病原.[方法]从罗甸县境内的不同麻疯树种植地点采集典型的根腐病病根标本,并对其病原物进行了分离培养、致病性测试以及形态特征观察.[结果]最终确认麻疯树根腐病病原菌为腐皮镰孢菌(Fusarium solani).[结论]为贵州罗甸县境内麻疯树根腐病的有效防治提供了参考.

  17. Effect of spent cotton stalks on color removal and chemical oxygen demand lowering in olive oil mill wastewater by white rot fungi.

    Science.gov (United States)

    Kahraman, S; Yeşilada, O

    1999-01-01

    Wastewater from olive oil mill was decolorized (and its chemical oxygen demand reduced in static cultivation) using the fungi Coriolus versicolor, Funalia trogii, Phanerochaete chrysosporium and Pleurotus sajor-caju. The effect of cotton stalk on decolorizing and COD removing capability was demonstrated. P. chrysosporium (in 20% medium with cotton stalk) reduced the COD by 48% and color by 58%, F. trogii (in 30% medium with cotton stalk)) by 51 and 55%, respectively.

  18. Clustering, haplotype diversity and locations of MIC-3: a unique root-specific defense-related gene family in upland cotton (Gossypium hirsutum L.)

    Science.gov (United States)

    MIC-3-related genes of cotton (Gossypium spp.) were identified and shown to have root-specific expression, associated with pathogen defense-related function and specifically increased expression in root-knot nematode (RKN) resistant plants after nematode infection. Here we cloned and sequenced MIC-...

  19. Transgenic sweet potato expressing thionin from barley gives resistance to black rot disease caused by Ceratocystis fimbriata in leaves and storage roots.

    Science.gov (United States)

    Muramoto, Nobuhiko; Tanaka, Tomoko; Shimamura, Takashi; Mitsukawa, Norihiro; Hori, Etsuko; Koda, Katsunori; Otani, Motoyasu; Hirai, Masana; Nakamura, Kenzo; Imaeda, Takao

    2012-06-01

    Black rot of sweet potato caused by pathogenic fungus Ceratocystis fimbriata severely deteriorates both growth of plants and post-harvest storage. Antimicrobial peptides from various organisms have broad range activities of killing bacteria, mycobacteria, and fungi. Plant thionin peptide exhibited anti-fungal activity against C. fimbriata. A gene for barley α-hordothionin (αHT) was placed downstream of a strong constitutive promoter of E12Ω or the promoter of a sweet potato gene for β-amylase of storage roots, and introduced into sweet potato commercial cultivar Kokei No. 14. Transgenic E12Ω:αHT plants showed high-level expression of αHT mRNA in both leaves and storage roots. Transgenic β-Amy:αHT plants showed sucrose-inducible expression of αHT mRNA in leaves, in addition to expression in storage roots. Leaves of E12Ω:αHT plants exhibited reduced yellowing upon infection by C. fimbriata compared to leaves of non-transgenic Kokei No. 14, although the level of resistance was weaker than resistance cultivar Tamayutaka. Storage roots of both E12Ω:αHT and β-Amy:αHT plants exhibited reduced lesion areas around the site inoculated with C. fimbriata spores compared to Kokei No. 14, and some of the transgenic lines showed resistance level similar to Tamayutaka. Growth of plants and production of storage roots of these transgenic plants were not significantly different from non-transgenic plants. These results highlight the usefulness of transgenic sweet potato expressing antimicrobial peptide to reduce damages of sweet potato from the black rot disease and to reduce the use of agricultural chemicals.

  20. Novel cotton homeobox gene and its expression profiling in root development and in response to stresses and phytohormones

    Institute of Scientific and Technical Information of China (English)

    Yongxiang Ni; Xiulan Wang; Dengdi Li; Yajie Wu; Wenliang Xu; Xuebao Li

    2008-01-01

    Homeodomain-leucine zipper (HD-Zip) proteins are transcriptional factors involved in plant development.In this study,one cDNA clone (Gossypium hirsutum homeobox1,designated GhHB1) encoding HD-Zip protein was isolated from a cotton root cDNA library.The GhHB1 cDNA is 1132 bp in length,including an 828 bp open reading frame that encodes a peptide with 275 amino acids,and 5'-/3'- untranslated regions.The predicted GhHB1 protein containing a homeodomain and a leucine-rich zipper motif shares relatively high identity with other plant HD-Zip proteins.Analysis using quantitative real-time RT-PCR indicated that the GhHB1 gene is predominantly expressed in roots and hypocotyls.Furthermore,GhHB1 transcripts were largely accumulated in early root development,and significantly reduced to very low levels as roots further developed,suggesting that the gene might function in the early development of roots.Under treatment with 1% NaCl,the expression level of the GhHB1 gene was dramatically increased in roots.Likewise,GhHB1 activity in roots was up-regulated by abscisic acid.These results imply that GhHB1 might play an important role in response to salt stress and to abscisic acid signaling.

  1. 勃利县红松根朽病防治技术的研究%Control Technology of Root-rot of Pinus koraiensis in Boli County

    Institute of Scientific and Technical Information of China (English)

    董双波; 曹月平; 朱宝珠

    2011-01-01

    通过调查、观测,掌握了红松根朽病在勃利县林区发病规律以及环境因素对该病害的影响。结果表明,红松根朽病的发病规律为:郁闭度大的林分病害较重,阴坡重于阳坡,山中下腹重于山上腹;使用树干基部涂药和根部注药相结合的方法防治效果最好,防治效果达95%以上。%Through survey observation,occurrence pattern of roo-rot of Pinus koraiensis in Boli county influence of environmental factors on this disease were mastered.Occurrence pattern of root-rot of Pinus koraiensis is that: plant disease of stand with large canopy density is severe;plant disease on shady slope are severe than that on sunny slope;plant disease on middle lower part of the mountain is severe than that on upper part of the mountain;combining the method of drug-coated on the base of the trunk and root injection can get the optimal control effect,which being 95% or more.

  2. Isolation and Pathogenicity of the Pathogens Causing Root Rot Disease of Atractylodes macrocephala Koidz%白术根腐病菌分离及致病性研究

    Institute of Scientific and Technical Information of China (English)

    杨成前; 吴中宝; 李品明; 韦中强; 肖杰易

    2012-01-01

    在同一地块通过对白术根腐病的发病情况进行调查,确定白术根腐病分为湿腐和干腐2种症状,湿腐为主要症状类型,在田间所占比例达69.68%.通过对30个病株样本进行病原分离,共分离得到131个菌株,12种分离菌中有7种对白术具有致病力,其中尖孢镰刀菌(Fusarium oxysporum)和茄病镰刀菌(F.solani)能产生白术根腐病的典型症状.尖孢镰刀菌为根腐病主要致病菌,并能导致两种症状,致病率达90%;茄病镰刀菌危害症状为湿腐,致病率为30%.%Investigation in one Atractylodes macrocephala plot showed that root rot of the plants had two different types of symptoms:dry rot and wet rot,and wet rot was the main symptom,accounting for 69.68% of the total.Altogether,131 fungus strains were isolated from 30 diseased plant samples.They belonged to 12 fungus species,of which 7 was pathogenic to A.macrocephala.Infection by Fusarium oxysporum and F.solani would produce typical symptoms of root rot.The main pathogen was F.oxysporum,which could cause both dry rot and wet rot,with a morbidity of 90%.F.solani had a morbidity of 30%,and its symptom was wet rot.

  3. Do jasmonates play a role in arbuscular mycorrhiza-induced local bioprotection of Medicago truncatula against root rot disease caused by Aphanomyces euteiches?

    Science.gov (United States)

    Hilou, Adama; Zhang, Haoqiang; Franken, Philipp; Hause, Bettina

    2014-01-01

    Bioprotective effects of mycorrhization with two different arbuscular mycorrhizal (AM) fungi, Funneliformis mosseae and Rhizophagus irregularis, against Aphanomyces euteiches, the causal agent of root rot in legumes, were studied in Medicago truncatula using phenotypic and molecular markers. Previous inoculation with an AM-fungus reduced disease symptoms as well as the amount of pathogen within roots, as determined by the levels of A. euteiches rRNA or transcripts of the gene sterol C24 reductase. Inoculation with R. irregularis was as efficient as that with F. mosseae. To study whether jasmonates play a regulatory role in bioprotection of M. truncatula by the AM fungi, composite plants harboring transgenic roots were used to modulate the expression level of the gene encoding M. truncatula allene oxide cyclase 1, a key enzyme in jasmonic acid biosynthesis. Neither an increase nor a reduction in allene oxide cyclase levels resulted in altered bioprotection by the AM fungi against root infection by A. euteiches. These data suggest that jasmonates do not play a major role in the local bioprotective effect of AM fungi against the pathogen A. euteiches in M. truncatula roots.

  4. The influence of soil moisture and Rhizoctonia solani anastomosis and intraspecific group on the incidence of damping-off and the incidence and severity of Rhizoctonia crown and root rot in sugar beet

    Science.gov (United States)

    Rhizoctonia crown and root rot (Rhizoctonia solani) reduces plant stands, sugar quality and yield in sugar beet. To evaluate the influence of R. solani anastomosis (AG) and intraspecific groups and soil moisture on disease incidence and severity, a field trial was established in Ridgetown, Ontario, ...

  5. Development of amplified fragment length polymorphism (AFLP)-derived specific primer for the detection of Fusarium solani aetiological agent of peanut brown root rot.

    Science.gov (United States)

    Casasnovas, F; Fantini, E N; Palazzini, J M; Giaj-Merlera, G; Chulze, S N; Reynoso, M M; Torres, A M

    2013-06-01

    The objective of this work was to design an amplified fragment length polymorphism (AFLP)-derived specific primer for the detection of Fusarium solani aetiological agent of peanut brown root rot (PBRR) in plant material and soil. Specific primers for the detection of the pathogen were designed based on an amplified region using AFLPs. The banding patterns by AFLPs showed that isolates from diseased roots were clearly distinguishable from others members of the F. solani species complex. Many bands were specific to F. solani PBRR, one of these fragments was selected and sequenced. Sequence obtained was used to develop specific PCR primers for the identification of pathogen in pure culture and in plant material and soil. Primer pair FS1/FS2 amplified a single DNA product of 175 bp. Other fungal isolates occurring in soil, included F. solani non-PBRR, were not detected by these specific primers. The assay was effective for the detection of pathogen from diseased root and infected soils. The designed primers for F. solani causing PBRR can be used in a PCR diagnostic protocol to rapidly and reliably detect and identify this pathogen. These diagnostic PCR primers will aid the detection of F. solani causing PBRR in diseased root and natural infected soils. The method developed could be a helpful tool for epidemiological studies and to avoid the spread of this serious disease in new areas. © 2013 The Society for Applied Microbiology.

  6. RNAi blockage of desoxyhemigossypol-6-OMT decreases the amounts of methylated sesquiterpenoids in transgenic cotton roots

    Science.gov (United States)

    After pathogen attack, plants produce compounds, called phytoalexins that are toxic to microorganisms. In the case of the cotton plant, these include desoxyhemigossypol (dHG), desoxyhemigossypol-6-methyl ether (dMHG), hemigossypol (HG), and hemigossypol-6-methyl ether (MHG), written in the order of...

  7. Variation of Saponins in Panax notoginseng Root Rot Diseases by LC -MS%LC -MS 分析三七根腐病的皂苷类成分变化

    Institute of Scientific and Technical Information of China (English)

    泰瑞清; 谈文状; 杨恩; 冯阳; 李海舟

    2015-01-01

    LC -MS method is used to study saponins in normal and root rot of P.notoginseng.and to meas-ure the concentration of H2 O2 and MDA in fresh herbs as a means to find out the possible reason for the change.The LC -MS analysis shows that 13 peaks in the normal of P.notoginseng are identified,and 7 new compounds from the root rot of P.notoginseng are detected.These new compounds are oxidation prod-ucts from saponins.Moreover,the levels of oxidation are significantly increased after being infected root rot diseases (P <0.01 ).The oxidation products of saponins from root rot P.notoginseng are probably caused by root rot diseases.%以高分辨的液质联用(LC -MS)技术分析正常三七和根腐病三七中皂苷类成分差异,检测新鲜药材中过氧化氢(H2 O2)和丙二醛(MDA)的浓度,探讨其变化可能的原因.正常三七中确定13个色谱峰,而根腐病三七中新产生7种成分,多为三七皂苷的氧化产物.此外,发现根腐病三七较正常的氧化水平显著提高(P <0.01).推测根腐病三七的皂苷类成分变化可能是由于病害后引起氧化水平升高而形成的氧化产物.

  8. Antagonism of local isolates of Trichoderna spp.on citrus root rot disease by Fusarium solani in the mekong delta of vietnam

    Institute of Scientific and Technical Information of China (English)

    Duong Minh; Jozef Coosemans; Le Lam Cuong; Ester Vandersmissen; Pham Van Kim

    2004-01-01

    @@ The local isolates of Trichoderrma spp. and Fusariun solani were colected from citrus orchards in the Mekong delta of Vietnam and isolated on PDA, PDB and TSM medium for antagonism and Koch's postulate testing. The results showed that the high chitinolytic enzymes content of Trichoderma isolates can antagonise with Fusarium solani isolates by preventing the germination of Fusarium macroconidia in in-vitro condition. There are five promising isolates of Trichoderna spp. having high antagonism with Fusarium solani. These Trichoderma isolates also grew well in rice straws, maize stems, weeds and water hyacinth biowaste materials. These results supply the promising trend for biological control of root rot disease on citrus orchards of the Mekong delta.

  9. Comparative effect of partial root-zone drying and deficit irrigation on incidence of blossom-end rot in tomato under varied calcium rates

    DEFF Research Database (Denmark)

    Sun, Yanqi; Feng, Hao; Liu, Fulai

    2013-01-01

    This study investigated the comparative effects of reduced irrigation regimes—partial root-zone drying (PRD) and conventional deficit irrigation (DI)—on the incidence of blossom-end rot (BER) in tomato (Solanum lycopersicum L.) under three Ca-fertilization rates: 0, 100, and 200mg Ca kg–1 soil...... xylem sap abscisic acid concentration, lower stomatal conductance, and higher plant water status in the PRD in relation to the DI plants might have contributed to the increased fruit Ca uptake, and could have reduced BER development in tomato fruits. Therefore, under conditions with limited freshwater...... resources, application of PRD irrigation could be a promising approach for saving water and for preventing BER development in tomatoes....

  10. Biological Control of Fusarium oxysporum f. sp. melonis, the Causal Agent of Root Rot Disease of Greenhouse Cucurbits in Kerman Province of Iran

    Directory of Open Access Journals (Sweden)

    Sara Shafii Bafti

    2005-01-01

    Full Text Available Antagonistic activity of 178 soil actinomycete isolates was assayed against Fusarium oxysporum f. sp. melonis Schlecht, Emend (Snyde and Hansen cause of root rot and fusarium wilt of greenhouse cucurbits in Kerman Province, southeast of Iran. From tested isolates, Streptomyces olivaceus (strain 115 showed anti-fusarium activity revealed through screening and bioassays by agar disk and well-diffusion methods. The active strain was grown in submerged cultures for determination of growth curve and preparation of crude extract for further biological characterizations. Antifungal activity was fungistatic type on the pathogen mycelia. It is prominent that amending greenhouse soil mix with the S. olivaceus (strain 115 will reduce crop losses by the pathogen.

  11. Managing Phytophthora crown and root rot on tomato by pre-plant treatments with biocontrol agents, resistance inducers, organic and mineral fertilizers under nursery conditions

    Directory of Open Access Journals (Sweden)

    Giovanna GILARDI

    2014-09-01

    Full Text Available Five trials were carried out under greenhouse conditions to test the efficacy of spray programmes based on biocontrol agents, phosphite-based fertilizers and a chemical inducer of resistance (acibenzolar-S-methyl, phosethyl-Al to control crown and root rot of tomato incited by Phytophthora nicotianae. The best disease control, under high disease pressure resulting from artificial inoculation, was obtained with three pre-plant leaf sprays at 7 d intervals with acibenzolar-S-methyl and with two mineral phosphite-based fertilizers. The disease reduction achieved was similar to that obtained with a single application of azoxystrobin and metalaxyl-M. Phosetyl-Al and the biocontrol agents Glomus spp. + Bacillus megaterium + Trichoderma, B. subtilis QST713, B. velezensis IT45 and the mixture T. asperellum ICC012 + T. gamsii ICC080 provided a partial disease control. Brassica carinata pellets did not control the disease.

  12. Impact of motility and chemotaxis features of the rhizobacterium Pseudomonas chlororaphis PCL1606 on its biocontrol of avocado white root rot.

    Science.gov (United States)

    Polonio, Álvaro; Vida, Carmen; de Vicente, Antonio; Cazorla, Francisco M

    2017-06-01

    The biocontrol rhizobacterium Pseudomonas chlororaphis PCL1606 has the ability to protect avocado plants against white root rot produced by the phytopathogenic fungus Rosellinia necatrix. Moreover, PCL1606 displayed direct interactions with avocado roots and the pathogenic fungus. Thus, nonmotile (flgK mutant) and non-chemotactic (cheA mutant) derivatives of PCL1606 were constructed to emphasize the importance of motility and chemotaxis in the biological behaviour of PCL1606 during the biocontrol interaction. Plate chemotaxis assay showed that PCL1606 was attracted to the single compounds tested, such as glucose, glutamate, succinate, aspartate and malate, but no chemotaxis was observed to avocado or R. necatrix exudates. Using the more sensitive capillary assay, it was reported that smaller concentrations (1 mM) of single compounds elicited high chemotactic responses, and strong attraction was confirmed to avocado and R. necatrix exudates. Finally, biocontrol experiments revealed that the cheA and fglK derivative mutants reduced root protection against R. necatrix, suggesting an important role for these biological traits in biocontrol by P. chlororaphis PCL1606. [Int Microbiol 20(2):94-104 (2017)]. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  13. Applications of volatile compounds acquired from Muscodor heveae against white root rot disease in rubber trees (Hevea brasiliensis Müll. Arg.) and relevant allelopathy effects.

    Science.gov (United States)

    Siri-Udom, Sakuntala; Suwannarach, Nakarin; Lumyong, Saisamorn

    The bioactive compounds of the volatile metabolite-producing endophytic fungus, Muscodor heveae, were examined by the process of biofumigation for the purposes of controlling white root rot disease in rubber trees (Hevea brasiliensis Müll. Arg.). Volatile organic compounds (VOCs) of M. heveae possess antimicrobial activity against Rigidoporus microporus in vitro with 100 % growth inhibition. The synthetic volatile compounds test confirmed that the major component, 3-methylbutan-1-ol, and the minor compounds, 3-methylbutyl acetate and 2-methylpropanoic acid, inhibited root and shoot growth in the tested plants 3-methylbutan-1-ol showed ED50 value and MIQ value on seed germination of ruzi grass, Arabidopsis thaliana Col-0 and tomato at 10, 5 and 5 μL(-1) airspace, respectively. In vivo tests were carried out under greenhouse conditions using M. heveae inoculum fumigated soil that had been inoculated with R. microporus inoculum. After which, all seven treatments were compared. Significant differences were observed with a disease score at 150 d after treatment. Biofumigation by M. heveae showed great suppression of the disease. Biocontrol treatments; RMH40 (40 g kg(-1)M. heveae inoculum) and RMH80 (80 g kg(-1)M. heveae inoculum) were not found to be significantly different when compared with fungicide treatment (RT) and the non-infected control, but results were found to be significantly different from R. microporus infested (R) treatment. RMH40 and RMH80 revealed a low disease scores with a high survival rate of rubber tree seedling at 100 %, while R treatment showed the highest disease score of 4.8 ± 0.5 with a survival rate of rubber tree seedling at 25 %. The infected roots, appearing as a white colour. We have concluded that the bioactive VOCs of M. heveae would be an alternative method for the control of white root rot disease in rubber trees. Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  14. 首次报道由异丝腐霉(Pythium diclinum)引起的烟草根腐病%First Report on Root Rot of Tobacco Caused by Pythium diclinum

    Institute of Scientific and Technical Information of China (English)

    劳超; 刘云龙; 谢勇; 王力; 田泽宇; 孔聪聪; 兰建强

    2012-01-01

    For the purpose of ascertaining the pathogen which caused root rot of tobacco seedling in floating system in Yanglin Town, Kunming City, Yunnan Province, the isolates that caused root rot in seedlings of tobacco floating were obtained from samples that they were fetched from three points of the tobacco NC297 seedling in floating system base and 10 samples were fetched from each point. These samples were analyzed by pathogenicity test, characteristic identified and 5. 8 rDNA-ITS sequence. Incidence rate of root rot of tobacco seedling was 100% . The homology between 5. 8 rDNA-ITS sequence of the pathogen and 5. 8 rDNA-ITS sequence of GenBank: AY666087. 1 (Pythium diclinum Tokunaga in Ito & Tokunaga) was 99% . The pathogen which was induced by the pieces of cucumber could generate a lot of spores. Pythium diclinum was identified to be the pathogen of root rot of tobacco seedlings in floating system. According to the symptoms and pathogen, the disease was defined as the root rot of tobacco seedling in floating system which was caused by P. Diclinum. This is the first report of root rot of tobacco caused by P. Diclinum.%为了明确引起云南省昆明市杨林镇烟草漂浮育苗过程中出现的根腐病的病原,在该烟草漂浮育苗基地取3点,分别在各点采集病株10个样本,烟草品种为NC297,对样本进行了病原菌分离、致病性测定、形态学鉴定和5.8 rDNA-ITS序列分析.结果表明,致病性试验中烟苗发病率为100%;病原菌的5.8 rDNA-ITS序列与GenBank:AY666087.1(Pythium diclinum Tokunaga in Ito&Tokunaga)同源性为99%;异丝腐霉通过黄瓜片诱导后能产生大量孢子;引起该烟草漂浮育苗根腐病的病原菌为异丝腐霉(Pythium diclinum);根据症状和病原菌,将此病害定为由异丝腐霉(Pythium diclinum)引起的烟草漂浮育苗根腐病;异丝腐霉引起烟草根腐病为首次报道.

  15. Biocontrol de la pudrición de raíz de nochebuena de interior con Trichoderma spp. Root rot biocontrol for indoor poinsettia with Trichoderma spp.

    Directory of Open Access Journals (Sweden)

    Felipe de Jesús Osuna-Canizalez

    2012-06-01

    Full Text Available En Morelos, la pudrición de la raíz causada por Fusarium spp., es una de las principales enfermedades de la nochebuena de interior. Por su efecto devastador, en su prevención o control se realizan aplicaciones frecuentes de productos químicos, con los riesgos inherentes a la salud humana y al ambiente. En la búsqueda de alternativas bioracionales al manejo de esta enfermedad, se realizó un ensayo en el que se evaluaron tres cepas comerciales de Trichoderma spp., en tres diferentes sustratos: S1= "tierra de hoja" (70% v/v+tezontle grueso (15% v/v+tezontle fino (10% v/v+agrolita (5% v/v; S2= turba (80% v/v+ fibra de coco (20% v/v; S3= "tierra de hoja" (70% + "tepojal" (30%, en las variedades comerciales más comunes, Freedom Red y Prestige Red. Se utilizó un diseño factorial de tratamientos 4 x 3 x 2 y los tratamientos resultantes se evaluaron en un diseño completamente al azar con seis repeticiones. Respecto a la incidencia de pudrición de la raíz, las cepas comerciales de Trichoderma spp., no mostraron diferencias entre sí ni con el testigo químico. La pudrición de la raíz estuvo asociada con S2, debido a una baja capacidad de aireación, y sólo se presentó en Prestige Red. La población (UFC g-¹ de Trichoderma spp., en el sustrato al término del ciclo, fue igual (pIn Morelos, root rot caused by Fusarium spp., is one of the main diseases of indoor poinsettia. In order to prevent or control its devastating effect, frequent applications of chemical products are performed, with inherent risks to human health and environment. In quest for alternative biorational options, an essay in which three commercial strains of Trichoderma spp., was done, in three different substrates: S1= "organic soil" (70% v/v+thick tezontle (15% v/v+thin tezontle (10% v/v+agrolita (5% v/v; S2= peat moss (80% v/v+ coconut fiber (20% v/v; S3= "organic soil" (70%+"tepojal" (30%, in most common commercial varieties, Freedom Red and Prestige Red. A factorial

  16. Meloidogyne incognita emigration from cotton roots may be induced by the resistance QTL qMi-C11

    Science.gov (United States)

    Upland cotton (Gossypium hirsutum) is one of the most widely grown crops in the southern US, and Meloidogyne incognita is the most significant pathogen of cotton in the US. Two QTLs, qMi-C11 and qMi-C14, conferring resistance to M. incognita have been identified in cotton. Previous research docume...

  17. Isolation and functional characterization of a cotton ubiquitination-related promoter and 5'UTR that drives high levels of expression in root and flower tissues

    Directory of Open Access Journals (Sweden)

    Viana Antonio AB

    2011-11-01

    Full Text Available Abstract Background Cotton (Gossypium spp. is an important crop worldwide that provides raw material to 40% of the textile fiber industry. Important traits have been studied aiming the development of genetically modified crops including resistance to insect and diseases, and tolerance to drought, cold and herbicide. Therefore, the characterization of promoters and regulatory regions is also important to achieve high gene expression and/or a specific expression pattern. Commonly, genes involved in ubiquitination pathways are highly and differentially expressed. In this study, we analyzed the expression of a cotton ubiquitin-conjugating enzyme (E2 family member with no previous characterization. Results Nucleotide analysis revealed high identity with cotton E2 homologues. Multiple alignment showed a premature stop codon, which prevents the encoding of the conserved cysteine residue at the E2 active site, and an intron that is spliced in E2 homologues, but not in GhGDRP85. The GhGDRP85 gene is highly expressed in different organs of cotton plants, and has high transcript levels in roots. Its promoter (uceApro2 and the 5'UTR compose a regulatory region named uceA1.7, and were isolated from cotton and studied in Arabidopsis thaliana. uceA1.7 shows strong expression levels, equaling or surpassing the expression levels of CaMV35S. The uceA1.7 regulatory sequence drives GUS expression 7-fold higher in flowers, 2-fold in roots and at similar levels in leaves and stems. GUS expression levels are decreased 7- to 15-fold when its 5'UTR is absent in uceApro2. Conclusions uceA1.7 is a strong constitutive regulatory sequence composed of a promoter (uceApro2 and its 5'UTR that will be useful in genetic transformation of dicots, having high potential to drive high levels of transgene expression in crops, particularly for traits desirable in flower and root tissues.

  18. Trichoderma spp. decrease Fusarium root rot in common bean Trichoderma spp. reduzem a podridão-radicular de Fusário em feijoeiro comum

    Directory of Open Access Journals (Sweden)

    Hudson Teixeira

    2012-12-01

    Full Text Available The effectiveness of six Trichoderma-based commercial products (TCP in controlling Fusarium root rot (FRR in common bean was assessed under field conditions. Three TCP, used for seed treatment or applied in the furrow, increased seedling emergence as much as the fungicide fludioxonil. FRR incidence was not affected, but all TCP and fludioxonil reduced the disease severity, compared to control. Application of Trichoderma-based products was as effective as that of fludioxonil in FRR management.A eficácia de seis produtos comerciais à base de Trichoderma (PCT no controle da podridão-radicular-seca do feijoeiro (PRS foi avaliada em condições de campo. Três PCT, usados no tratamento de sementes ou aplicados no sulco de plantio, aumentaram a emergência das plântulas tanto quanto o fungicida fludioxonil. A incidência de PRS não foi afetada, mas todos os PCT e o fludioxonil reduziram a severidade em relação à testemunha. A aplicação de produtos à base de Trichoderma spp. foi tão eficaz quanto o fludioxonil no manejo da PRS.

  19. Genome sequences of two Phytophthora species responsible for Sudden Oak Death and Soybean Root Rot provide novel insights into their evolutionary origins and mechanisms of pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, Brett M.; Tripathi, Sucheta; Aerts, Andrea; Bensasson, Douda; Dehal, Paramvir; Dubchak, Inna; Garbelotto, Matteo; Gijzen, Mark; Huang, Wayne; Ivors, Kelly; Jiang, Rays; Kamoun, Sophien; Krampis, Konstantinos; Lamour, Kurt; McDonald, Hayes; Medina, Monica; Morris, Paul; Putnam, Nik; Rash, Sam; Salamov, Asaf; Smith, Brian; Smith, Joe; Terry, Astrid; Torto, Trudy; Grigoriev, Igor; Rokhsar, Daniel; Boore, Jeffrey

    2005-12-01

    The approximately 60 species of Phytophthora are all destructive pathogens, causing rots of roots, stems, leaves and fruits of a wide range of agriculturally and ornamentally important plants (1). Some species, such as P. cinnamomi, P. parasitica and P. cactorum, each attack hundreds of different plant host species, whereas others are more restricted. Some of the crops where Phytophthora infections cause the greatest financial losses include potato, soybean, tomato, alfalfa, tobacco, peppers, cucurbits, pineapple, strawberry, raspberry and a wide range of perennial tree crops, especially citrus, avocado, almonds, walnuts, apples and cocoa, and they also heavily affect the ornamental, nursery and forestry industries. The economic damage overall to crops in the United States by Phytophthora species is estimated in the tens of billions of dollars, including the costs of control measures, and worldwide it is many times this amount (1). In the northern midwest of the U.S., P. sojae causes $200 million in annual losses to soybean alone, and worldwide causes around $1-2 billion in losses per year. P. infestans infections resulted in the Irish potato famine last century and continues to be a difficult and worsening problem for potato and tomato growers worldwide, with worldwide costs estimated at $5 billion per year.

  20. Transient silencing mediated by in vitro synthesized double-stranded RNA indicates that PsCdc14 is required for sporangial development in a soybean root rot pathogen.

    Science.gov (United States)

    Zhao, Wei; Yang, Xinyu; Dong, Suomeng; Sheng, Yuting; Wang, Yuanchao; Zheng, Xiaobo

    2011-12-01

    In many eukaryotic organisms, Cdc14 phosphatase regulates multiple biological events during anaphase and is essential for mitosis. It has been shown that Cdc14 is required for sporulation in the potato blight pathogen Phytophthora infestans; however, the role that the Cdc14 homolog (PsCdc14) plays in the soil-borne soybean root rot pathogen P. sojae remains ambiguous. PsCdc14 is highly expressed in sporulation, zoospore, and cyst life stages, but not in vegetative mycelia and infection stages, suggesting that it contributes to asexual reproduction and thus the spread of the disease. Double-stranded RNA (dsRNA) mediates gene silencing, a post-transcriptional and highly conserved process in eukaryotes, involving specific gene silencing through degradation of target mRNA. We combined in vitro dsRNA synthesis and a polyethylene glycol-mediated transformation system to construct a dsRNA-mediated transient gene silencing system; and then performed a functional analysis of PsCdc14 in P. sojae. PsCdc14 mRNA was dramatically reduced in transformants after protoplasts were exposed in in vitro synthesized PsCdc14 dsRNA, resulting in low sporangial production and abnormal development in P. sojae silencing lines. Furthermore, dsRNA-mediated transient gene silencing could enable elucidation of P. sojae rapid gene function, facilitating our understanding of the development and pathogenicity mechanisms of this oomycete fungus.

  1. 台湾褐根病发生情况及研究进展%Research advances of brown root rot (Phellinus noxius) in Taiwan, China

    Institute of Scientific and Technical Information of China (English)

    林石明; 廖富荣; 陈红运; 陈青; 陈华忠

    2012-01-01

    褐根病菌是中国大陆的检疫性有害生物。褐根病是由有害木层孔菌(Phellinus noxius(Comer)Cunningham)引起经济作物、果树、景观名木古树和园林绿化等植物的毁灭性土传病害。近年来,在台湾的59科140多种植物上普遍发生并严重危害。本文综述了台湾在褐根病方面的研究进展,内容包括该病原菌的寄主、形态特征和生物学特性,病害发生发展规律和防治措施以及检测与鉴定方法。%Phellinus noxius is one of the quarantine pest of China mainland. It causes brown root rot of fruit and ornamental tree, which is a destructive disease of ancient and famous trees. P. noxius is a soil - borne pathogen. The disease is spreading among 59 families, more than 140 species of host plants these years in Taiwan. We expatiated recent research advances in Taiwan, China, including morphological and biological characteristics, spread model and control measurements and the detection & identification methods.

  2. Expression of GhNAC2 from G. herbaceum, improves root growth and imparts tolerance to drought in transgenic cotton and Arabidopsis.

    Science.gov (United States)

    Gunapati, Samatha; Naresh, Ram; Ranjan, Sanjay; Nigam, Deepti; Hans, Aradhana; Verma, Praveen C; Gadre, Rekha; Pathre, Uday V; Sane, Aniruddha P; Sane, Vidhu A

    2016-04-26

    NAC proteins are plant-specific transcription factors that play essential roles in regulating development and responses to abiotic and biotic stresses. We show that over-expression of the cotton GhNAC2 under the CaMV35S promoter increases root growth in both Arabidopsis and cotton under unstressed conditions. Transgenic Arabidopsis plants also show improved root growth in presence of mannitol and NaCl while transgenic cotton expressing GhNAC2 show reduced leaf abscission and wilting upon water stress compared to control plants. Transgenic Arabidopsis plants also have larger leaves, higher seed number and size under well watered conditions, reduced transpiration and higher relative leaf water content. Micro-array analysis of transgenic plants over-expressing GhNAC2 reveals activation of the ABA/JA pathways and a suppression of the ethylene pathway at several levels to reduce expression of ERF6/ERF1/WRKY33/ MPK3/MKK9/ACS6 and their targets. This probably suppresses the ethylene-mediated inhibition of organ expansion, leading to larger leaves, better root growth and higher yields under unstressed conditions. Suppression of the ethylene pathway and activation of the ABA/JA pathways also primes the plant for improved stress tolerance by reduction in transpiration, greater stomatal control and suppression of growth retarding factors.

  3. Effect of elicitors on the production of gossypol and methylated gossypol in cotton hairy roots

    Science.gov (United States)

    The effect of two-chemical elicitors, salicylic acid and methyl jasmonate, on the production of gossypol, 6-methoxy gossypol, and 6,6'-dimethoxy gossypol in Gossypium barbadense hairy roots was examined. Methyl jasmonate, but not salicylic acid, was found to increase the production of gossypol and ...

  4. Reação de cultivares de abacateiro à podridão de raízes Reaction of avocado cultivars to avocado root rot

    Directory of Open Access Journals (Sweden)

    Ciro Hideki Sumida

    2009-07-01

    Full Text Available As cultivares de abacateiro (Persea americana Mill 'Margarida', 'Fortuna' e 'Hass' têm muita importância econômica no mercado nacional e internacional. Em função disso, este trabalho teve como objetivo avaliar a reação dessas cultivares frente à Phytophthora cinnamomi Rands., agente causal da podridão das raízes. A inoculação do patógeno foi feita por meio de implantação de tecidos de raízes sintomáticas. Foram inoculadas quatro raízes em três árvores diferentes, uma de cada cultivar, em três pontos diferentes da raiz. Em cada cultivar, das quatro raízes, uma foi utilizada como testemunha, nas quais foram implantados tecidos sadios. A avaliação foi realizada aos 120 dias após a inoculação, observando-se as raízes externamente quanto à alteração da coloração e presença de estruturas de patógenos na região da superfície da casca nos pontos inoculados. Internamente, foram removidas as cascas para visualização das alterações a partir do ponto inoculado, sendo observadas alterações de coloração dos tecidos e realizada mensuração da extensão do escurecimento (lesão aparente. Nas extremidades das lesões foram retirados segmentos de raízes e implantados em meio de cultivo farinha de milho-ágar e incubados, para verificação da colonização na área sem escurecimento, ou seja, a colonização não- aparente. Das cultivares avaliadas, a 'Hass' foi a menos suscetível ao P. cinnamomi, quando comparada às cultivares 'Fortuna' e 'Margarida'. O patógeno P. cinnamomi pode apresentar desenvolvimento ou colonização nos tecidos radiculares além da área sintomática.Cultivars of the avocado (Persea americana Mill 'Margarida', 'Fortuna' and 'Geada' have importance in the national and international markets. The present paper had as objective to evaluate the reaction of such cultivars to Phytophthora cinanamomi Rands, the causal agent of avocado root rot. They were inoculated four roots in three different

  5. Effect of CO2 enhancement on beech (Fagus sylvatica L. seedling root rot due to Phytophthora plurivora and Phytophthora cactorum

    Directory of Open Access Journals (Sweden)

    Tkaczyk Miłosz

    2014-09-01

    Full Text Available Global climate change is associated with higher concentrations of atmospheric carbon dioxide (CO2. The ongoing changes are likely to have significant, direct or indirect effects on plant diseases caused by many biotic agents such as phytopathogenic fungi. This study results showed that increased CO2 concentration did not stimulate the growth of 1-year-old beech Fagus sylvatica L seedlings but it activated pathogenic Phytophthora species (P. plurivora and P. cactorum which caused significant reduction in the total number of fine roots as well as their length and area. The results of the greenhouse experiment indicated that pathogens once introduced into soil survived in pot soil, became periodically active (in sufficient water conditions and were able to damage beech fine roots. However, the trees mortality was not observed during the first year of experiment. DNA analyses performed on soil and beech tissue proved persistence of introduced Phytophthora isolates.

  6. Identification of early salt-stress responsive proteins in seedling roots of upland cotton (Gossypium hirsutum L. employing iTRAQ-based proteomic technique

    Directory of Open Access Journals (Sweden)

    Wu eLi

    2015-09-01

    Full Text Available Soil salinity is a major abiotic stress that limits plant growth and agricultural productivity. Upland cotton (Gossypium hirsutum L. is highly tolerant to salinity; however, large-scale proteomic data of cotton in response to salt-stress are still scanty. Here, an iTRAQ-based proteomic technique was employed to identify the early differentially expressed proteins (DEPs from salt-treated cotton roots. 77 up-regulated and 52 down-regulated proteins were identified. The majority of the proteins have functions related to carbohydrate and energy metabolism, transcription related, protein metabolism, cell wall and cytoskeleton metabolism, membrane and transport, signal transduction, as well as stress and defense. It is worth emphasizing that some novel salt-responsive proteins were identified, which involved in cell cytoskeleton metabolism(ARP2 and FLAs), membrane transport(TIPs and PIPs), signal transduction(LRR-RLKs)and stress responses(TLP, USP, DIR,desiccation-related protein PCC13-62. High positive correlation was evaluated between the abundance of some altered proteins (SOD, POD, GST, MDAR and MDH and their enzyme activity. The results demonstrate the iTRAQ-based proteomic technique is reliable for identifying and quantifying a large number of cotton root proteins. qRT-PCR was used to study the gene expression levels of five above-mentioned proteins, four patterns are consistent with those of induced protein. These results showed that cotton’s proteome to NaCl stress is complex, and that the comparative protein profiles of roots under salinity vs control improve the understanding of the molecular mechanisms involved in the tolerance of plants to salt stress. It provides a good starting point for further functional elucidation of these DEPs using genetic and/or other approaches, and thereby candidate genes for genetic engineering to improve crop salt tolerance.

  7. Monitoring of Soft Fruit Mother Plantings Aimed at Control of Phytophthora fragariae, Causal Agent of Root Rot

    Directory of Open Access Journals (Sweden)

    Slobodan Milenković

    2006-12-01

    Full Text Available Phytophthora fragariae was first detected in the Republic of Serbia in 2002, and it has been included in A2 quarantine list of damaging organisms since 2003. The project titled ‘Monitoring of soft fruit mother plantings aimed at the control of Phytophthora fragariae, causal agent of root rot’ was realized over 2004 – 2005 aiming at determination of population rate of the pathogen and the control of raspberry planting material. Over that period, the total 388 samples were tested. Collected samples were analyzed by PCR. The presence of Phytophthora fragariae was detected in 156 samples.

  8. 土壤生境抑制烟草根黑腐病研究进展%Research Advance of Suppression Effect of Soil Habitat on Tobacco Black Root Rot

    Institute of Scientific and Technical Information of China (English)

    饶兴义; 霍沁建; 曹务栋; 张梦; 蒋卫

    2011-01-01

    Tobacco black root rot once resulting in great loss was a worldwide fungal disease. This paper gave a concise introduction on the outbreak of tobacco black root rot in our nation recent years, and the pathogenicbacteria, biological characteristics, infection and symptom of this disease, and then summarized the effects of soil habitat factors, included soil physi-chemical properties, soil nutrient status, root exudates and soil microorganism, on tobacco black root rot. At last, we raised some procedures, such as improving field management and cultivation strategies, reasonable fertilization and biocontrol, to ameliorate soil habitat and control the disease.%烟草根黑腐病是一种世界性真菌病,曾给各主要种烟国造成巨大损失.为此简述了近20年来烟草根黑腐病在中国各主要种烟省份爆发流行的状况,并对此病害的病原菌、生物学特性、侵染和病症特征加以介绍,总结了土壤理化性质、土壤养分状况、根系分泌物和土壤微生物等土壤生境因子对该病病原菌存活、侵染、病害爆发的影响,提出通过加强田间管理、改进栽培策略、合理施用肥料、引入生物防治等措施,以改善土壤生境为目标,抑制烟草根黑腐病爆发.

  9. The mitochondrial malate dehydrogenase 1 gene GhmMDH1 is involved in plant and root growth under phosphorus deficiency conditions in cotton.

    Science.gov (United States)

    Wang, Zhi-An; Li, Qing; Ge, Xiao-Yang; Yang, Chun-Lin; Luo, Xiao-Li; Zhang, An-Hong; Xiao, Juan-Li; Tian, Ying-Chuan; Xia, Gui-Xian; Chen, Xiao-Ying; Li, Fu-Guang; Wu, Jia-He

    2015-07-16

    Cotton, an important commercial crop, is cultivated for its natural fibers, and requires an adequate supply of soil nutrients, including phosphorus, for its growth. Soil phosporus exists primarily in insoluble forms. We isolated a mitochondrial malate dehydrogenase (MDH) gene, designated as GhmMDH1, from Gossypium hirsutum L. to assess its effect in enhancing P availability and absorption. An enzyme kinetic assay showed that the recombinant GhmMDH1 possesses the capacity to catalyze the interconversion of oxaloacetate and malate. The malate contents in the roots, leaves and root exudates was significantly higher in GhmMDH1-overexpressing plants and lower in knockdown plants compared with the wild-type control. Knockdown of GhmMDH1 gene resulted in increased respiration rate and reduced biomass whilst overexpression of GhmMDH1 gave rise to decreased respiration rate and higher biomass in the transgenic plants. When cultured in medium containing only insoluble phosphorus, Al-phosphorus, Fe-phosphorus, or Ca-phosphorus, GhmMDH1-overexpressing plants produced significantly longer roots and had a higher biomass and P content than WT plants, however, knockdown plants showed the opposite results for these traits. Collectively, our results show that GhmMDH1 is involved in plant and root growth under phosphorus deficiency conditions in cotton, owing to its functions in leaf respiration and P acquisition.

  10. Mapping of a Novel Race Specific Resistance Gene to Phytophthora Root Rot of Pepper (Capsicum annuum) Using Bulked Segregant Analysis Combined with Specific Length Amplified Fragment Sequencing Strategy.

    Science.gov (United States)

    Xu, Xiaomei; Chao, Juan; Cheng, Xueli; Wang, Rui; Sun, Baojuan; Wang, Hengming; Luo, Shaobo; Xu, Xiaowan; Wu, Tingquan; Li, Ying

    2016-01-01

    Phytophthora root rot caused by Phytophthora capsici (P. capsici) is a serious limitation to pepper production in Southern China, with high temperature and humidity. Mapping PRR resistance genes can provide linked DNA markers for breeding PRR resistant varieties by molecular marker-assisted selection (MAS). Two BC1 populations and an F2 population derived from a cross between P. capsici-resistant accession, Criollo de Morelos 334 (CM334) and P. capsici-susceptible accession, New Mexico Capsicum Accession 10399 (NMCA10399) were used to investigate the genetic characteristics of PRR resistance. PRR resistance to isolate Byl4 (race 3) was controlled by a single dominant gene, PhR10, that was mapped to an interval of 16.39Mb at the end of the long arm of chromosome 10. Integration of bulked segregant analysis (BSA) and Specific Length Amplified Fragment sequencing (SLAF-seq) provided an efficient genetic mapping strategy. Ten polymorphic Simple Sequence Repeat (SSR) markers were found within this region and used to screen the genotypes of 636 BC1 plants, delimiting PhR10 to a 2.57 Mb interval between markers P52-11-21 (1.5 cM away) and P52-11-41 (1.1 cM). A total of 163 genes were annotated within this region and 31 were predicted to be associated with disease resistance. PhR10 is a novel race specific gene for PRR, and this paper describes linked SSR markers suitable for marker-assisted selection of PRR resistant varieties, also laying a foundation for cloning the resistance gene.

  11. Characterization of Fusarium isolates from asparagus fields in southwestern Ontario and influence of soil organic amendments on Fusarium crown and root rot.

    Science.gov (United States)

    Borrego-Benjumea, Ana; Basallote-Ureba, María J; Melero-Vara, José M; Abbasi, Pervaiz A

    2014-04-01

    Fusarium crown and root rot (FCRR) of asparagus has a complex etiology with several soilborne Fusarium spp. as causal agents. Ninety-three Fusarium isolates, obtained from plant and soil samples collected from commercial asparagus fields in southwestern Ontario with a history of FCRR, were identified as Fusarium oxysporum (65.5%), F. proliferatum (18.3%), F. solani (6.4%), F. acuminatum (6.4%), and F. redolens (3.2%) based on morphological or cultural characteristics and polymerase chain reaction (PCR) analysis with species-specific primers. The intersimple-sequence repeat PCR analysis of the field isolates revealed considerable variability among the isolates belonging to different Fusarium spp. In the in vitro pathogenicity screening tests, 50% of the field isolates were pathogenic to asparagus, and 22% of the isolates caused the most severe symptoms on asparagus. The management of FCRR with soil organic amendments of pelleted poultry manure (PPM), olive residue compost, and fish emulsion was evaluated in a greenhouse using three asparagus cultivars of different susceptibility in soils infested with two of the pathogenic isolates (F. oxysporum Fo-1.5 and F. solani Fs-1.12). Lower FCRR symptom severity and higher plant weights were observed for most treatments on 'Jersey Giant' and 'Grande' but not on 'Mary Washington'. On all three cultivars, 1% PPM consistently reduced FCRR severity by 42 to 96% and increased plant weights by 77 to 152% compared with the Fusarium control treatment. Populations of Fusarium and total bacteria were enumerated after 1, 3, 7, and 14 days of soil amendment. In amended soils, the population of Fusarium spp. gradually decreased while the population of total culturable bacteria increased. These results indicate that soil organic amendments, especially PPM, can decrease disease severity and promote plant growth, possibly by decreasing pathogen population and enhancing bacterial activity in the soil.

  12. Identification of Biocontrol Bacteria against Soybean Root Rot with Biolog Automatic Microbiology Analysis System%拮抗大豆根腐病细菌的Biolog鉴定

    Institute of Scientific and Technical Information of China (English)

    许艳丽; 刘海龙; 李春杰; 潘凤娟; 李淑娴; 刘新晶

    2012-01-01

    In order to identify the systematic position of taxonomy of two biocontrol bacteria against soybean root rot. Traditional morphological identification and BIOLOG automatic microbiology analysis system were used to identify strain B021a and B04b. The results showed that similarity value of strain B021a with Vibrio tubiashii was 0. 634, possibility to 86% and genetic distance to 4.00,and similarity value of strain B04b with Pasteurella trehalosi was 0. 610,probability to 75% and genetic distance to 2. 77. Strain B021a was identified as Vibrio tubiashii and strain B04b as Pasteurella trehalosi by colony morphological propertie and BIOLOC analysis system.%为明确2株生防细菌的分类地位,采用传统形态学方法结合Biolog微生物自动分析系统,鉴定了大豆根腐病的2株生防细菌.结果表明,菌株B021a与塔式弧菌相似度值为0.634,可能性是86%,遗传距离为4.00.菌株B04b与海藻巴斯德菌相似度值为0.610,可能性是75%,遗传距离为2.77.综合形态学和Biolog鉴定结果,认为菌株B021a是塔式弧菌,菌株B04b是海藻巴斯德菌.

  13. Clustering, haplotype diversity and locations of MIC-3: a unique root-specific defense-related gene family in Upland cotton (Gossypium hirsutum L.).

    Science.gov (United States)

    Buriev, Zabardast T; Saha, Sukumar; Abdurakhmonov, Ibrokhim Y; Jenkins, Johnie N; Abdukarimov, Abdusattor; Scheffler, Brian E; Stelly, David M

    2010-02-01

    MIC-3 is a recently identified gene family shown to exhibit increased root-specific expression following nematode infection of cotton plants that are resistant to root-knot nematode. Here, we cloned and sequenced MIC-3 genes from selected diploid and tetraploid cotton species to reveal sequence differences at the molecular level and identify chromosomal locations of MIC-3 genes in Gossypium species. Detailed sequence analysis and phylogenetic clustering of MIC-3 genes indicated the presence of multiple MIC-3 gene members in Gossypium species. Haplotypes of a MIC-3 gene family member were discovered by comparative analysis among consensus sequences across genotypes within an individual clade in the phylogram to overcome the problem of duplicated loci in the tetraploid cotton. Deficiency tests of the SNPs delimited six A(t)-genome members of the MIC-3 family clustered to chromosome arm 4sh, and one D(t)-genome member to chromosome 19. Clustering was confirmed by long-PCR amplification of the intergenic regions using A(t)-genome-specific MIC-3 primer pairs. The clustered distribution may have been favored by selection for responsiveness to evolving disease and/or pest pressures, because large variants of the MIC-3 gene family may have been recovered from small physical areas by recombination. This could give a buffer against selection pressure from a broad range of pest and pathogens in the future. To our knowledge, these are the first results on the evolution of clustering and genome-specific haplotype members of a unique cotton gene family associated with resistant response against a major pathogen.

  14. Investigations on root and stem rot diseases of oat (Avena sativa L. with a special regard to temperature and rainfalls

    Directory of Open Access Journals (Sweden)

    Irena Kiecana

    2013-12-01

    Full Text Available Investigations were carried out in 1996-2000 in the Experimental Station of Cultivars Evaluation in Uhnin. Disease symptoms were recorded twice - in the seedling stage (18 in the Tottman's scale and in milk ripe stage (77 in the Tottman's scale of oat. The seedlings with root and sheath necrosis or plants with diseased stem base were obtained every year. The percentage of diseased seedlings ranged from 6,0 to 39,5. and percentage of older plants with necrotic stripes on lower internodes ranged from 11,5 to 5O,0.Results of mycological analysis of diseased plants showed that Fusarium spp., especially F.avenaceum and F.culmorum were isolated the most frequently, F.avenaceum was obtained in the seasons with different weather conditions. This indicates great tolerance of this fungus to temperature and humidity. In the seasons with high temperature F.culmorum was predominant. This species also can be tolerant to changing weather conditions. Warm and wet weather was favourable for oat infection by Bipolaris sorokiniana. Rhizoctonia solani was isolated from plants in milk ripe stage in each vegetation seasons. and from seedlings in years 1998 and 1999.

  15. Interactive effects of carbon dioxide, low temperature, and ultraviolet-B radiation on cotton seedling root and shoot morphology and growth

    Science.gov (United States)

    Brand, David; Wijewardana, Chathurika; Gao, Wei; Reddy, K. Raja

    2016-09-01

    Interactive effects of multiple environmental stresses are predicted to have a negative effect on cotton growth and development and these effects will be exacerbated in the future climate. The objectives of this study were to test the hypothesis that cotton cultivars differ in their responses to multiple environmental factors of (CO2) [400 and 750 µmol·mol-1 (+(CO2)], temperature [28/20 and 20/12°C (-T)], and UV-B radiation [0 and 10 kJ·m-2·d-1 (+ UV-B)]. A genetic and molecular standard (TM-1) and three modern cotton cultivars (DP1522B2XF, PHY496W3R, and ST4747GLB2) were grown in eight sunlit, controlled environment chambers with control treatment 400 µmol·mol-1 [CO2], 28/21°C temperature, and 0 kJ UV-B. The results showed significant differences among the cultivars for most of the shoot and root parameters. Plants grown under low temperature alone or as a combination with + UV-B treatment caused more detrimental effects on root and shoot vigor. Although the elevated CO2 treatments weakened the damaging effects of higher UV-B levels on cotton growth on all cultivars, increased CO2 could not mask the negative effects of low temperature. When comparing all cultivars, genetic standard TM-1 produced the smallest values for the majority of traits under CO2, UV-B, and low temperature either alone or in combination with other treatments. Based on principal component analysis, the four cultivars were classified as tolerant (DP1522B2XF), intermediate (PHY496W3R and ST4747GLB2) and sensitive (TM-1) to multiple environmental stresses.Low temperature was identified as the most damaging treatment to cotton early seedling vigor while elevated CO2 caused the least. Existing variability of cotton cultivars in response to multiple environmental stresses could allow for selection of cultivars with the best coping ability and higher lint yield for future climate change environments.

  16. Detection and characterization of broad-spectrum antipathogen activity of novel rhizobacterial isolates and suppression of Fusarium crown and root rot disease of tomato.

    Science.gov (United States)

    Zhang, L; Khabbaz, S E; Wang, A; Li, H; Abbasi, P A

    2015-03-01

    To detect and characterize broad-spectrum antipathogen activity of indigenous bacterial isolates obtained from potato soil and soya bean leaves for their potential to be developed as biofungicides to control soilborne diseases such as Fusarium crown and root rot of tomato (FCRR) caused by Fusarium oxysporum f. sp. radicis-lycopersici (Forl). Thirteen bacterial isolates (Bacillus amyloliquefaciens (four isolates), Paenibacillus polymyxa (three isolates), Pseudomonas chlororaphis (two isolates), Pseudomonas fluorescens (two isolates), Bacillus subtilis (one isolate) and Pseudomonas sp. (one isolate)) or their volatiles showed antagonistic activity against most of the 10 plant pathogens in plate assays. Cell-free culture filtrates (CF) of five isolates or 1-butanol extracts of CFs also inhibited the growth of most pathogen mycelia in plate assays. PCR analysis confirmed the presence of most antibiotic biosynthetic genes such as phlD, phzFA, prnD and pltC in most Pseudomonas isolates and bmyB, bacA, ituD, srfAA and fenD in most Bacillus isolates. These bacterial isolates varied in the production of hydrogen cyanide (HCN), siderophores, β-1,3-glucanases, chitinases, proteases, indole-3-acetic acid, salicylic acid, and for nitrogen fixation and phosphate solubilization. Gas chromatography-mass spectrometry analysis identified 10 volatile compounds from 10 isolates and 18 compounds from 1-butanol extracts of CFs of five isolates. Application of irradiated peat formulation of six isolates to tomato roots prior to transplanting in a Forl-infested potting mix and field soil provided protection of tomato plants from FCRR disease and enhanced plant growth under greenhouse conditions. Five of the 13 indigenous bacterial isolates were antagonistic to eight plant pathogens, both in vitro and in vivo. Antagonistic and plant-growth promotion activities of these isolates might be related to the production of several types of antibiotics, lytic enzymes, phytohormones, secondary

  17. 甘肃渭源蒙古黄芪根腐病病原菌的分离与鉴定%Isolation and identification of the pathogens causing Astragalus membranaceus var.mongholicus root rot in Weiyuan of Gansu Province

    Institute of Scientific and Technical Information of China (English)

    陈垣; 朱蕾; 郭凤霞; 武志江

    2011-01-01

    Root rot is one of the limitations of sustainable Astragalus membranaceus var. Mongholicus production. Six kinds of fungi were isolated from diseased plant samples with root rot symptom in Weiyuan county of Gansu Province. Based on pathogenicity tests, the major pathogens were Fusarium oxysporum and F. Solani, with the isolation percentage of 15. 8% -38. 1% and 25. 0%-42. 1% respectively at different growth stages. The incidence of root rot after inoculation of pathogens on goring seedling radicles was significantly higher than that on non-goring radicles. F. Oxysporum was showed to have a strong pathogenicity. All the results indicated that the climate, soil condition and seedlings, healthy state were contributory factors for root rot disease. It is suggested that healthy plant seedlings without wound under the standard operation is important for controlling A. Membranaceus var. Mongholicus root rot.%黄芪是豆科黄芪属蒙古黄芪[Astragalus membranaceus(Fisch.)Bge.var.mongholicus(Bge.)Hsiao]或膜荚黄芪[A membranceus(Fisch.)Bge.]的干燥根,主要成分有皂苷类、黄酮类、多糖及其它成分.具有补气固表、利尿托毒、排脓、敛疮生肌之功效[1].黄芪为多年生药用植物,野生资源贫乏,需求量大,现主要人工种植.蒙古黄芪原产于山西、内蒙、河北、陕西和甘肃等地.甘肃陇西、渭源、临洮和岷县等地种植的蒙古黄芪因品质优、产量高已成为我国主要的道地黄芪产区.然而,近几年根腐病(root rot)普遍发生,感病后轻者根部表皮粗糙(占35%~92%),重者呈褐色腐朽状.经研究,其致病菌有尖孢镰刀菌(Fusarium oxysporum Schlecht.)和腐皮镰孢菌(F.solani (Mart.)Sacc)[2].Luo等[3]曾提出一些防治措施,这对黄芪根腐病的发生与综防提供了一定参考,但由于对黄芪根腐病病原菌缺乏系统研究,因此,开展甘肃道地产区蒙古黄芪根腐病病原菌的分离和鉴定对进一步认识和防治该病具有重要意义.

  18. Jasmonic acid and salicylic acid inhibit growth of three sugarbeet storage rot pathogens

    Science.gov (United States)

    Storage rots contribute to postharvest losses by consuming sucrose and increasing carbohydrate impurities that increase sugar loss to molasses during processing. They also increase root respiration rate, which causes additional sucrose loss and contributes to pile warming. Currently, storage rots ...

  19. Endophytic bacteria from Piper tuberculatum Jacq.: isolation, molecular characterization, and in vitro screening for the control of Fusarium solani f. sp piperis, the causal agent of root rot disease in black pepper (Piper nigrum L.).

    Science.gov (United States)

    Nascimento, S B; Lima, A M; Borges, B N; de Souza, C R B

    2015-07-06

    Endophytic bacteria have been found to colonize internal tissues in many different plants, where they can have several beneficial effects, including defense against pathogens. In this study, we aimed to identify endophytic bacteria associated with roots of the tropical piperaceae Piper tuberculatum, which is known for its resistance to infection by Fusarium solani f. sp piperis, the causal agent of black pepper (Piper nigrum) root rot disease in the Amazon region. Based on 16S rRNA gene sequence analysis, we isolated endophytes belonging to 13 genera: Bacillus, Paenibacillus, Pseudomonas, Enterobacter, Rhizobium, Sinorhizobium, Agrobacterium, Ralstonia, Serratia, Cupriavidus, Mitsuaria, Pantoea, and Staphylococcus. The results showed that 56.52% of isolates were associated with the phylum Proteobacteria, which comprised α, β, and γ classes. Other bacteria were related to the phylum Firmicutes, including Bacillus, which was the most abundant genus among all isolates. Antagonistic assays revealed that Pt12 and Pt13 isolates, identified as Pseudomonas putida and Pseudomonas sp, respectively, were able to inhibit F. solani f. sp piperis growth in vitro. We describe, for the first time, the molecular identification of 23 endophytic bacteria from P. tuberculatum, among which two Pseudomonas species have the potential to control the pathogen responsible for root rot disease in black pepper in the Amazon region.

  20. Evaluation of microbial products for the control of zucchini foot and root rot caused by Fusarium solani f. sp. cucurbitae race 1

    Directory of Open Access Journals (Sweden)

    Roberta ROBERTI

    2012-09-01

    for an effective management of zucchini Fusarium foot and root rot through rhizosphere competence and several mechanisms exerted by their microbial ingredients.

  1. Desenvolvimento do sistema radicular do algodoeiro na camada arável do solo Distribution of cotton roots in the upper soil layers at three different time intervals

    Directory of Open Access Journals (Sweden)

    A. C. Magalhães

    1962-01-01

    Full Text Available Sabe-se que o sistema radicular do algodoeiro se situa predominantemente na região compreendida pelos primeiros 20 cm de profundidade do solo. Como a cultura exige intensas práticas culturais, torna-se útil conhecer a distribuição progressiva do sistema radicular naquela região, sobretudo nos primeiros meses do ciclo vegetative época em que a cultura exige a intensificação das capinas. Estudos sôbre a questão foram efetuados em um ensaio de campo com a variedade IAC 12-57/566, em solo tipo terra-roxa-misturado, fozendo-se observações aos 42, 61 e 81 dias após a germinação das sementes. Os dados mostraram maior concentração de raízes na camada de 3 a 15 cm de profundidade do solo e até a uma distância aproximada de 25 cm lateralmente às plantas. O ritmo de crescimento do sistema radicular do algodoeiro foi mais intenso do 42.° ao 61.° dia após a germinação. A má utilização dos implementos agrícolas nesse período mais critico, poderá pois, provocar grandes danos à cultura, principalmente se forem empregados cultivos profundos.The distribution of the cotton plant root system in the upper 20 cm layer of soil was studied at three different times (42, 61 ond 81-day old plants. These studies were carried out in a cotton field of the variety IAC 12-57/566 planted on a "terra-roxa-misturada" type of soil. The spacing was 80 cm between rows and 15 cm between plants in the row. The method employed consisted in excavating a ditch at a right angle to the plant rows, including four plants, and then removing the soil as blocks. Five loyers of soil blocks were taken: the first and second were 3 cm thick; the third, 4 cm thick; and the fourth and fifth, 5 cm thick. After washing off the soil of each block, the roots in it were air dried and weighed. A representation of the root distribution os encountered is given in figure 2. Far the cotton field studied, most of the roots were found between 3 and 15 cm of depth up to a

  2. Chromium (VI) Uptake and Tolerance Potential in Cotton Cultivars: Effect on Their Root Physiology, Ultramorphology, and Oxidative Metabolism

    National Research Council Canada - National Science Library

    Daud, M. K; Mei, Lei; Variath, M. T; Ali, Shafaqat; Li, Cheng; Rafiq, M. T; Zhu, S. J

    2014-01-01

    .... Four different levels of Cr (CK, 10, 50, and 100 μM) were applied. Cr caused a significant reduction in root/shoot length, number of secondary roots, and root fresh and dry biomasses at 100 μM...

  3. 甘肃高寒阴湿区豌豆根腐镰刀菌种群及致病性研究%Fusarium Population and Pathogenicity of Pea Root Rot in the Cold and Humid Regions of Gansu Province

    Institute of Scientific and Technical Information of China (English)

    刘小娟; 侯思雯; 杨晓明; 李敏权

    2012-01-01

    甘肃省高寒阴湿区豌豆镰刀菌根腐病的病原有5种,即茄病镰刀菌[ Fusarium solani ( Mart.) Sacc]、茄病镰刀菌蓝色变种(Fusarium solani var.coeruleum)、半裸镰刀菌(Fusarium semitectum)、单隔镰刀菌(Fusarium dimerum)、拟丝孢镰刀菌(Fusarium trichothecioides).茄病镰刀菌致病性最强,拟丝孢镰刀菌和茄病镰刀菌蓝色变种次之,半裸镰刀菌和单隔镰刀菌的致病性较弱.其中半裸镰刀菌、单隔镰刀菌、拟丝孢镰刀菌是中国豌豆病原菌上的新纪录.%The pathogen of pea Fusarium root rot in the cold and humid regions of Gansu were Fusarium solani (Mart. ) Sacc., Fusarium solani var. Coeruleum,, Fusarium semitectum ? Fusarium dimerum and Fusarium trichothe-cioides. The most pathogeniciry pathogen was F. Solani, while F. Trichothecioides, and F. Solani var. Coeruleum were the second;however F. Semitectum and F. Dimerum were the least pathogenicity pathogens. F. semitectumNF. Dime-rum ^F. Trichothecioides were new recorded on pea Fusarium root rot in China.

  4. 豇豆根腐病病原分离鉴定及其核糖体rDNA-ITS序列分析%Pathogeny Isolation and Identification of Cowpea Root Rot Disease and Sequencing of Ribosomal rDNA-ITS

    Institute of Scientific and Technical Information of China (English)

    吴仁锋; 杨绍丽; 万鹏; 黄薇

    2011-01-01

    The fungal isolate JGF from cowpea root rot disease, which were collected from Wuhan, were studied morphologically and molecularly. The results showed that the isolate JGF were morphological Fusarium solani Schl. The rDNA-ITS genes of isolate JGF were amplified and sequenced. Based on the Blast search and the alignment analysis in GenBank database combined with morphological characters, the pathogen of cowpea root rot disease was identified as Fusarium solani Schl.%采用形态学及分子生物学的方法对采集自武汉的豇豆根腐病分离物进行形态学和分子生物学鉴定.结果表明,菌株JGF形态学上为茄腐皮镰孢菌;对JGF菌株的核糖体RNA基因内转录间隔区(rDNA-ITS)进行了PCR扩增和序列测定,并在GenBank中进行了Blast搜索和比对分析,根据rDNA-ITS序列分析结果结合豇豆病株症状和病菌的形态学特征,认为武汉地区豇豆根腐病的病原菌为茄腐皮镰孢菌(Fusarium solani Schl.)

  5. 烟草根黑腐病菌致病力分化及品种抗性差异研究%Pathogenicity differentiation of Thielaviopsis basicola and resistance difference of tobacco against black root rot

    Institute of Scientific and Technical Information of China (English)

    窦彦霞; 李兰; 彭雄; 肖崇刚; 周常勇

    2012-01-01

    Thielaviopsis basicola (Berk,et Br. ) Ferr. causing tobacco black root rot were isolated with modified carrot disks from 5 provinces of China, and their pathogenicity differentiation were studied by root cutting inoculation method. In the study, the disease resistances of 7 main tobacco cultivars against different T. basicola isolates were also evaluated. A total of 14 isolates of T. basicola were obtained, and their pathogenicity showed significant difference. The disease index of 14 isolates ranged from 29.2 to 62.5, in which 4 isolates showed high pathogenicity, 10 isolates were at moderate level, and no weak pathogenic isolate was found. The disease resistances were significantly different among the 7 cultivars when different cultivars were inoculated by a certain T. basicola isolates. The disease resistance changed from resistant, moderate resistant to susceptible and highly susceptible. The resistance of Guiyan 4, Qinyan 96 and Zhongyan 100 were higher than those of other tested cultivars.

  6. Effects of silicon treatment and inoculation with Fusarium oxysporum f. sp. vasinfectum on cellular defences in root tissues of two cotton cultivars.

    Science.gov (United States)

    Whan, Jennifer A; Dann, Elizabeth K; Aitken, Elizabeth A B

    2016-08-01

    Silicon has been shown to enhance the resistance of plants to fungal and bacterial pathogens. Here, the effect of potassium silicate was assessed on two cotton (Gossypium hirsutum) cultivars subsequently inoculated with Fusarium oxysporum f. sp. vasinfectum (Fov). Sicot 189 is moderately resistant whilst Sicot F-1 is the second most resistant commercial cultivar presently available in Australia. Transmission and light microscopy were used to compare cellular modifications in root cells after these different treatments. The accumulation of phenolic compounds and lignin was measured. Cellular alterations including the deposition of electron-dense material, degradation of fungal hyphae and occlusion of endodermal cells were more rapidly induced and more intense in endodermal and vascular regions of Sicot F-1 plants supplied with potassium silicate followed by inoculation with Fov than in similarly treated Sicot 189 plants or in silicate-treated plants of either cultivar not inoculated with Fov. Significantly more phenolic compounds were present at 7 d post-infection (dpi) in root extracts of Sicot F-1 plants treated with potassium silicate followed by inoculation with Fov compared with plants from all other treatments. The lignin concentration at 3 dpi in root material from Sicot F-1 treated with potassium silicate and inoculated with Fov was significantly higher than that from water-treated and inoculated plants. This study demonstrates that silicon treatment can affect cellular defence responses in cotton roots subsequently inoculated with Fov, particularly in Sicot F-1, a cultivar with greater inherent resistance to this pathogen. This suggests that silicon may interact with or initiate defence pathways faster in this cultivar than in the less resistant cultivar. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Effect of Woody Debris abundance on daytime refuge use by cotton mice.

    Energy Technology Data Exchange (ETDEWEB)

    Hinkelman, Travis, M.; Loeb, Susan, C.

    2007-07-01

    Abstract - Daytime refuges are important to nocturnal rodents for protection from predators and environmental extremes. Because refuges of forest-dwelling rodents are often associated with woody debris, we examined refuge use by 37 radio-collared Peromyscus gossypinus (cotton mice) in experimental plots with different levels of woody debris. Treatment plots had six times (≈ 60 m3/ha) the volume of woody debris as control plots (≈ 10 m3/ha). Of 247 refuges, 159 were in rotting stumps (64%), 32 were in root boles (13%), 19 were in brush piles (8%), and 16 were in logs (6%); 10 refuges could not be identified. Stumps were the most common refuge type in both treatments, but the distribution of refuge types was significantly different between treatment and control plots. Root boles and brush piles were used more on treatment plots than on control plots, and logs were used more on control plots than on treatment plots. Refuge type and vegetation cover were the best predictors of refuge use by cotton mice; root bole refuges and refuges with less vegetation cover received greater-than-expected use by mice. Abundant refuges, particularly root boles, may improve habitat quality for cotton mice in southeastern pine forests.

  8. Chemical signals and their regulations on the plant growth and water use efficiency of cotton seedlings under partial root-zone drying and different nitrogen applications

    Directory of Open Access Journals (Sweden)

    Wenrao Li

    2017-03-01

    Full Text Available Partial root-zone drying during irrigation (PRD has been shown effective in enhancing plant water use efficiency (WUE, however, the roles of chemical signals from root and shoot that are involved and the possible interactions affected by nitrogen nutrition are not clear. Pot-grown cotton (Gossypium spp. seedlings were treated with three levels of N fertilization and PRD. The concentrations of nitrate (NO3−, abscisic acid (ABA and the pH value of leaf and root xylem saps, biomass and WUE were measured. Results showed that PRD plants produced larger biomass and higher WUE than non-PRD plants, with significant changes in leaf xylem ABA, leaf and root xylem NO3− concentrations and pH values, under heterogeneous soil moisture conditions. Simultaneously, high-N treated plants displayed larger changes in leaf xylem ABA and higher root xylem NO3− concentrations, than in the medium- or low-N treated plants. However, the WUE of plants in the low-N treatment was higher than that of those in the high- and medium-N treatments. PRD and nitrogen levels respectively induced signaling responses of ABA/NO3− and pH in leaf or root xylem to affect WUE and biomass under different watering levels, although significant interactions of PRD and nitrogen levels were found when these signal molecules responded to soil drying. We conclude that these signaling chemicals are regulated by interaction of PRD and nitrogen status to regulate stomatal behavior, either directly or indirectly, and thus increase PRD plant WUE under less irrigation.

  9. 大麦种质资源苗期根腐病抗性鉴定%Assessment of Root Rot Resistance in a Collection of Barley Germplasm at the Seedling Stage

    Institute of Scientific and Technical Information of China (English)

    吕二锁; 张凤英; 蔺瑞明; 包海柱; 刘志萍

    2015-01-01

    试验采用孢子悬浮液喷雾接种法,对国内外205份大麦种质资源材料进行实验室苗期根腐病抗性筛选、鉴定。结果表明,有11份材料高抗根腐病,35份材料中抗根腐病,156份材料中感或高感根腐病;以发病严重度为分析变量做品种抗病性聚类分析,取欧式距离为2.14时,品种抗病性可分为两大类,第一类抗病材料(包括高抗与中抗)总共有46份,占供试鉴定材料的22.44%;第二类感病材料(包括中感与高感)总共有156份,占供试鉴定材料的77.09%;获得的抗病材料可作为抗病育种亲本材料,为丰富和拓展我国大麦抗病育种种质资源奠定基础。%This study assessed root rot resistance in a collection of 205 samples of barley germplasm originating domestically and inter-nationally using the method of sprays for inoculating the spore suspension of the pathogen. As a result, 11 and 35 barley samples had high and medium resistance, respectively, to root rot disease, while 156 samples were moderately or highly susceptible to the disease. A clustering analysis was conducted using disease severity as the variable with Euclidean distance of 2. 14, which divided these samples into two groups based on their disease resistance. The first group was considered disease-resistant materials, which comprised 46 sam-ples with medium or high resistance to root rot disease, accounting for 22. 44% of all collected samples. The second group was consid-ered disease-susceptible materials, which consisted of 156 samples with moderate or high susceptibility to the disease, constituting 77. 09% of all samples. The samples resistant to the disease can be used as parental materials for breeding disease-resistant barley varieties. Therefore, the current study laid a foundation for enriching disease-resistant barley germplasm resources in China.

  10. Comparison of Four Kinds of Seed Coating Agents on Root Rot Control Efficiency of Soybean%4种种衣剂对大豆根腐病的防效比较

    Institute of Scientific and Technical Information of China (English)

    米娜瓦尔·艾买提; 刘利群

    2013-01-01

    [目的]研究4种种衣剂防治大豆根腐病的综合效应.[方法]以大豆主栽品种阿豆1号作为试材,将大豆种子采用4种种衣剂处理后播种在根腐病严重的病土中,测定其出苗率、株高、病株率、死亡率、病情指数等指标.[结果]在根腐病严重的土壤条件下,4种种衣剂处理中,除处理Ⅰ和Ⅳ的出苗率显著低于对照以外,处理Ⅱ和Ⅲ均保持与对照相同的水平;虽然种衣剂处理后,大豆须根数量有一定程度的减少,但其株高有所提高,病株率、死亡率和病情指数有不同程度的下降.[结论]4种种衣剂对大豆根腐病的防病效果有差异,效果大小顺序依次为36.8%阿维菌素·多菌灵·福美双(ADF)悬浮种衣剂(Ⅱ)、40%卫福悬浮种衣剂(Ⅲ)、35% kdf悬浮种衣剂(Ⅰ)、18%福克悬浮种衣剂(Ⅳ).%[Objective] To study the combined prevention effect of four kind of seed coating agent on soybean root rot.[Method] With soybean cultivar "Adou No.1" as test material,after soybean seeds were coated by four kinds of seed coating agent,sown it in serious root rot disease soil,and measured their emergence rate,plant height,diseased plant rate,mortality plant rate,disease index and disease prevention efficiency.[Result] Under serious root rot soil conditions,among four kind of seed coating agent,except the Ⅰ and Ⅳ has a significantly lower emergence rate compared with the control,treatment Ⅱ and Ⅲ kept the same level emergence rate compared with the control.Although there were some degree reduce on the fibrous root number and nodule number of soybean after treated with four seed coating agent,but the diseased plant rate,mortality plant rate,disease index decreased in some degrees.[Conclusion] Some differences were occurred on the disease prevention efficiency of four seed coating agents on soybean root rot disease,the order:36.8% aweijunsu duojunling fumeishuang (ADF) seed coating agent (Ⅱ) >40% fuwei seed

  11. Effect of composts on microbial dynamics and activity, dry root rot severity and seed yield of cowpea in the Indian arid region

    Directory of Open Access Journals (Sweden)

    Meenu BAREJA

    2011-01-01

    Full Text Available Nutrient-deficient sandy soil, having poor moisture retention, favors  Macrophomina phaseolina, a soil-borne plant pathogen, occurring in severe form on many important crops grown in the Indian arid region. In a 2-year field experiment, five composts (4 ton/ha prepared from residues of Calotropis procera, Prosopis juliflora, Azadirachta indica, Acacia nilotica, and on-farm weeds were tested on cowpea (Vigna unguiculata to determine their effectiveness in limiting the  severity of charcoal rot caused by M. phaseolina in relation to the microbial population dynamics, microbial activity and the seed yield of cowpea.  In general, compost-amended plots retained 8.9% higher moisture than unamended plots. The microbial population increased in amended plots during the crop season. Populations of total fungi and actinomycetes were heighest in Calotropis compost-amended soil, while total bacteria were maximum in weed- compost amended soil. Microbial activity in amended plots was  26.3% higher than in unamended plots. Among trace elements,  uptake of Zn, Mn, Fe and Cu was  heighest  in plants grown in weed-compost amended soil followed by A. nilotica compost-amended soil. Soil amendment with the composts significantly reduced  plant mortality due to charcoal rot. The lowest mortality was recorded in plants amended with A. nilotica compost (5.5% followed by P. juliflora compost (5.8, while the  highest plant mortality (11.5% from charcoal rot occurred in the unamended control on the basis of the pooled average of two years. There was a significant inverse correlation between microbial activity and charcoal rot incidence in cowpea at 20 days after planting. Composts also had a beneficial effect on yield, with a 28.3% increase in seed yield in P. juliflora compost-amended plots. These results suggest that in resource-deficient farming , certain on-farm wastes can be effectively utilized for managing soil-borne pathogens, as well as  for

  12. Microbial antagonism as a potential solution for controlling selected root pathogens of crops

    Science.gov (United States)

    Cooper, Sarah; Agnew, Linda; Pereg, Lily

    2016-04-01

    Root pathogens of crops can cause large reduction in yield, however, there is a limited range of effective methods to control such pathogens. Soilborne pathogens that infect roots often need to survive in the rhizosphere, where there is high competition from other organisms. In such hot spots of microbial activity and growth, supported by root exudates, microbes have evolved antagonistic mechanisms that give them competitive advantages in winning the limited resources. Among these mechanisms is antibiosis, with production of some significant antifungal compounds including, antibiotics, volatile organic compounds, hydrogen cyanide and lytic enzymes. Some of these mechanisms may suppress disease through controlling the growth of root pathogens. In this project we isolated various fungi and bacteria that suppress the growth of cotton pathogens in vitro. The pathogen-suppressive microbes were isolated from cotton production soils that are under different management strategies, with and without the use of organic amendments. The potential of pathogen-suppressing microbes for controlling the black root rot disease, caused by the soilborne pathogen Thielaviopsis basicola, was confirmed using soil assays. We identified isolates with potential use as inoculant for cotton production in Australia. Having isolated a diverse group of antagonistic microbes enhances the probability that some would survive well in the soil and provide an alternative approach to address the problem of root disease affecting agricultural crops.

  13. Analysis of root-knot nematode and fusarium wilt disease resistance in cotton (Gossypium spp.) using chromosome substitution lines from two alien species.

    Science.gov (United States)

    Ulloa, M; Wang, C; Saha, S; Hutmacher, R B; Stelly, D M; Jenkins, J N; Burke, J; Roberts, P A

    2016-04-01

    Chromosome substitution (CS) lines in plants are a powerful genetic resource for analyzing the contribution of chromosome segments to phenotypic variance. In this study, a series of interspecific cotton (Gossypium spp.) CS lines were used to identify a new germplasm resource, and to validate chromosomal regions and favorable alleles associated with nematode or fungal disease resistance traits. The CS lines were developed in the G. hirsutum L. TM-1 background with chromosome or chromosome segment substitutions from G. barbadense L. Pima 3-79 or G. tomentosum. Root-knot nematode (Meloidogyne incognita) and fusarium wilt (Fusarium oxysporum f. sp. vasinfectum) (races 1 and 4) resistance alleles and quantitative trait loci (QTL) previously placed on cotton chromosomes using SSR markers in two interspecific recombinant inbred line populations were chosen for testing. Phenotypic responses of increased resistance or susceptibility in controlled inoculation and infested field assays confirmed the resistance QTLs, based on substitution with the positive or negative allele for resistance. Lines CS-B22Lo, CS-B04, and CS-B18 showed high resistance to nematode root-galling, confirming QTLs on chromosomes 4 and 22 (long arm) with resistance alleles from Pima 3-79. Line CS-B16 had less fusarium race 1-induced vascular root staining and higher percent survival than the TM-1 parent, confirming a major resistance QTL on chromosome 16. Lines CS-B(17-11) and CS-B17 had high fusarium race 4 vascular symptoms and low survival due to susceptible alleles introgressed from Pima 3-79, confirming the localization on chromosome 17 of an identified QTL with resistance alleles from TM1 and other resistant lines. Analyses validated regions on chromosomes 11, 16, and 17 harboring nematode and fusarium wilt resistance genes and demonstrated the value of CS lines as both a germplasm resource for breeding programs and as a powerful genetic analysis tool for determining QTL effects for disease

  14. 不同类型生物农药对大豆疫霉根腐病的防治效果%Control Efficiency of Different Biopesticides on Soybean Phytophthora Root Rot

    Institute of Scientific and Technical Information of China (English)

    申宏波; 姚文秋; 于永梅; 丁俊杰; 顾鑫; 杨晓贺; 赵海红; 文景芝

    2011-01-01

    对Harpins蛋白、B5、G3、嗜线虫杆菌、蜡介轮支菌菌土、“818”发酵液和恩益碧种衣剂7种不同类型生物农药对大豆疫霉根腐病的防治效果进行了比较,结果表明:以南京农业大学提供的Harpins蛋白在使用浓度为45 mg·L-l时防治效果最好,大豆疫霉根腐病的平均发病率仅为0.12%,防治效果达到75%,平均产量比对照增加7%.其次是中国农业科学院生物防治所提供的“818”发酵液,防治效果达到58.3%.45 mg· L-1 Harpins蛋白、“818”发酵液防效与对照的差异均达极显著水平.%The control effects of seven different types of biological pesticide on soybean Phytopktkora root rot were compared in this research. The incidence and prevention efficiency of phytophthora root rat, as well as soybean yield were determined. The results showed that 45 mg·L-1 Harpins protein from Nanjing Agricultural University had the best control effect,the average incidence of Phytophthora root rot of was 0.12% ,the prevention effect reached 75% and average yield was 7% higher than CK. The second was "818" fermentation liquid provided by the Chinese Academy of Agricultural Sciences, the prevention effect reached 58.3%. The control effect of 45 mg·L-1 Hatpins protein and "818" fermentation liquid were extremely significant different with CK.

  15. Biocontrol of Isatis indigotica root rot by the bacterial strain Bs-0728%拮抗细菌Bs-0728对板蓝根根腐病的防治作用

    Institute of Scientific and Technical Information of China (English)

    高琳娜; 曹克强; 段英姿; 王树桐

    2011-01-01

    [Objective] To screen effective antagonistic bacterium to Isatis indigotica root rot. [Method] Dural culture was conducted to test the antagonism of 201 bacterial strains isolated from 137 /. Indigotica rhizosphere soil samples. [Result] The bacterial strain Bs-0728 showed the highest antagonistic effect against the major /saris root rot pathogen Fusarium solani. Bs-0728 was highly inhibitory to F. Solani by making the mycelia swollen and curly. Treated with fermentation broth of Bs-0728 in field trials, the disease control efficacy reached 72. 97%, and the yield of /. Indigotica root increased by 86.26% compared with the untreated control. Identification by morphological observations, physiological and biochemical determination, and 16S rDNA sequence analysis showed that the strain belonged to Bacillus subtilis. [Conclusion] The stain Bs-0728 is a promising biological strain for application.%[目的]筛选对板蓝根根腐病有较强拮抗作用的生防菌株.[方法]采用平板对峙法对137个板蓝根根际土壤样本中分离到的201株拮抗细菌进行测试.[结果]筛选出1个对板蓝根根腐病菌有强烈抑制作用的菌株Bs0728.结合显微镜观察确定Bs-0728菌株对板蓝根根腐病的主要致病菌茄腐镰刀菌(Fusarium solani)菌丝生长有较强的抑制作用,导致菌丝生长畸形,弯曲,部分细胞膨大.田间试验结果表明,Bs-0728的发酵液田间防效达72.97%,且增产86.26%.经形态观察、生理生化反应及16S rDNA序列分析,初步将此拮抗细菌鉴定为枯草芽胞杆菌Bacillus subtilis.[结论]枯草芽孢杆菌Bs-0728菌株是一株很有应用前景的生防菌株.

  16. Effect of phosphorus and the arbuscular mycorrhizal fungus Glomus intraradices on disease severity of root rot of peas (Pisum sativum) caused by Aphanomyces euteiches

    DEFF Research Database (Denmark)

    Bødker, Lars; Kjøller, Rasmus; Rosendahl, Søren

    1998-01-01

    The effects of inorganic phosphate levels and the presence of arbuscular mycorrhiza on disease severity of Aphanomyces euteiches in pea roots were studied. Disease severity on roots and epicotyl as well as the oospore number within infected root tissue were correlated with the phosphorus (P) level...... in the growth medium. The arbuscular mycorrhizal fungus Glomus intraradices increased P uptake and the P concentration in the plant but reduced disease development in peas. Polyacrylamide gel electrophoresis followed by densitometry of glucose-6-phosphate dehydrogenase specific to A.euteiches was used...

  17. Fungi Diversity of Rhizosphere Soil with Loquat Root Rot Disease in Yunnan Province%云南蒙自枇杷根腐病植株根际土壤真菌多样性研究

    Institute of Scientific and Technical Information of China (English)

    杨若鹏; 郑肖兰; 田学军; 李建平; 鲁海菊

    2012-01-01

    摘要摸清蒙自枇杷根腐病病株根际土壤真菌区系分布.为有效可持续防控枇杷根腐病提供理论依据。采用五点取样法采集土壤样品,稀释平板法在PDA培养基上分离纯化,获得114株枇杷根腐病病株根际土壤真菌,经显微镜形态鉴定。109株真菌鉴定为以下24种: A bs idia corymbifera, A bsidia cylindrospora, A bsidia spinosa,Acremonium cerealis, Acremonium murorum, Aspergillus niger, Cladosporium cladosporioides, Colletotrichum dematium, Fusarium flocciferum, Mucor circineUoides f. janssenii, Mucor circinelloides f. wsitanicus, PeniciUium atrovenetum, Penicillium canescens, PeniciUium chrysogenum, Penicillium corylophilum, Penicillium daleae, Penicillium digitatum, Penicillium nigricans, Penicillium oxalicum, Penicillium saceulum, Penicillium variabile,Pythium intermedium, Trichoderma strigosum, Verticillium fungicola,分属于11个属.其中青霉属(Penicillium)是优势属,另外5株真菌属于担子菌。%To establish the species and distribution of fungi of Loquat rhizosphere soil which had rot root disease at Mengzi in Yunnan Province and to provide theoretical basis for efficient control to disease of the root rot; Soil specimen were collected with the 5-point method. The fungi strains were isolated by the plate of gradient dilution with PDA medium. The strains were identified by morphology with microscope. The strains respectively belong to A bsidia corymbifera, A bsidia cylindrospora, A bsidia spinosa, A cremonium cerealis, Acremonium murorum, Aspergillus niger, Cladosporium cladosporioides, Colletotrichum dematium, Fusarium flocciferum, Mucor circinelloides f. janssenii, Mucor circineUoides f. wsitanicus, Penicillium atrovenetum, Penicillium canescens, Penicillium chrysogenum, Penicillium corylophilum, PeniciUium daleae, Penicillium digitatum, Penicillium nigricans, PeniciUium oxalicum, Penicillium saceulum, PeniciUium variabile, Pythium intermedium, Trichoderma strigosum

  18. Establishment of the in vitro CottonRoot Tip Culture System%棉花离体根尖培养体系的建立

    Institute of Scientific and Technical Information of China (English)

    祝水金; 季道藩

    2000-01-01

    从培养基成分着手,研究了影响棉花离体根尖培养的各种因素,以建立棉花离体根尖培养体系。研究结果表明,棉花根尖培养的培养基为:MS大量元素+1/2 MS微量元素+100mg·L。肌醇+1.0mg·L。烟酸+10.0mg·L。盐酸硫胺素+L 0mg·L。盐酸吡哆辛+20mg·L。蔗糖+0.125mg·L。吲哚丁酸,用0.8%的琼脂为支撑物,调节pH值为6.4。培养温度为(28±2)℃,每天光照14 h,光照强度为2000 Lx。用此方法进行棉花根尖培养,离体根系可在培养基中生长达2个月而不影响其生活力。该棉花根尖培养体系适用于陆地棉和海岛棉,但基因型之间培养效果存在一定差异。%Conditions of cotton root tip culture invitro were studied in this paper. The recom-mended medium for cotton root tip culture invitro was macronutrients and iron salt of MS ba-sic medium, 1/2 micronutruents of MS basicmedium, vitamins and organic materials of B6basic medium containing 100mg · L-1 of inositol,1.0 mg· L1 of nicotonic acid, 10.0 mg· L-1 ofvitamin B1, 1.0 mg· L4 of vitamin B6, 20 mg ·L-1 of saccharose as the carbon resource and 0. 125 mg · L-t of IBA, using 0. 8% of agar asthe solid material and adjusting pH to 6.4. Thecotton root tips were cultured at a photoperiodof 14 hours daily with a light intensity of 2000Lx and temperature of (28±2)C . The excitedcotton roots could grow very well in the mediumfor more than two months with this culturemethod. This culture system was suitable forthe materials of both G. hirsutum and G. bar-badense, though some differences were presentamong the genotypes.

  19. 77 FR 48899 - Flutriafol; Pesticide Tolerances for Emergency Exemptions

    Science.gov (United States)

    2012-08-15

    ... in 2011, cotton growers suffered 30- 66 percent yield losses in fields infested with cotton root rot. Fields infested with cotton root rot disease last year are expected to have even heavier losses this year... conditions cotton root rot fungus flourished on stressed cotton plants to reduce yields and produce...

  20. Genetic differentiation of charcoal rot pathogen, Macrophomina phaseolina, into specific groups using URP-PCR.

    Science.gov (United States)

    Jana, T K; Singh, N K; Koundal, K R; Sharma, T R

    2005-02-01

    Forty isolates of Macrophomina phaseolina, a pathogen causing charcoal dry root rot of soybean, cotton, and chickpea, were genetically characterized with universal rice primers (URP; primers derived from DNA repeat sequences in the rice genome) using polymerase chain reaction (URP-PCR). Out of 12 URPs used in this study, 5 primers were effective in producing polymorphic fingerprint patterns from the DNA of M. phaseolina isolates. Three primers (URP-2F, URP-6R, and URP-30F) were quite informative and produced high levels of polymorphism among the isolates of M. phaseolina. Analysis of the entire fingerprint profiles using unweighted pair-group method with arithmetic averages (UPGMA) clearly differentiated M. phaseolina isolates obtained from soybean, cotton, and chickpea hosts into specific groups. In this study, we found for the first time transferability and use of PCR primers derived from plant genomes to generate host-specific fingerprint profiles of M. phaseolina, a broad host range plant pathogenic fungus. These results demonstrate that URPs are sensitive and technically simple to use for assaying genetic variability in M. phaseolina populations.

  1. Prediction of potential geographic distribution of strawberry red stele root rot (Phytophthora fragariae Hickman) in China using MAXENT%基于MAXENT的草莓疫霉红心病在中国的适生性分析

    Institute of Scientific and Technical Information of China (English)

    张静秋; 王振华; 龚国祥; 娄少之; 郑作良; 陈克

    2014-01-01

    Strawberry red stele root rot is a kind of destructive disease, it is important to prevent the expansion of the disease in China. Based on MAXENT model, we predicted the potential geographic distribution in China and analyzed the bioclimatic variables of the disease. The results showed that the main risky areas distributed in Yangtze River region, where there is also the main strawberry producing areas. Mean temperature of the coldest quarter, precipitation of the driest quarter and annual mean temperature were the main bioclimatic factors in the distribution of disease.%草莓疫霉红心病是草莓的重要病害,预防和控制该病害在中国扩展蔓延十分重要。本研究利用 MAXENT 生态位模型预测草莓疫霉红心病在中国的适生区并分析影响病害适生的环境变量,结果表明长江中下游流域草莓主产区是该病害的适生区。最冷季节平均温度、最干季度降水量和年平均温度是影响病害发展的主要因素。

  2. Molecular identification of Fusarium species isolated from transgenic insect-resistant cotton plants in Mexicali valley, Baja California.

    Science.gov (United States)

    Gonzalez-Soto, T; González-Mendoza, D; Troncoso-Rojas, R; Morales-Trejo, A; Ceceña-Duran, C; Garcia-Lopez, A; Grimaldo-Juarez, O

    2015-10-02

    Cotton production in the Mexicali valley is adversely affected by wilt and root rot disease associated with Fusarium species. In the present study, we sought to isolate and identify the Fusarium species in the rhizosphere of transgenic insect-resistant cotton plants grown in the Mexicali valley. Our analyses isolated four native fungi from the rhizosphere of cotton plants, namely, T-ICA01, T-ICA03, T-ICA04, and T-ICA08. These fungal isolates were categorized as belonging to Fusarium solani using their phenotypic characteristics and ITS region sequence data. Examination of the infection index showed that T-ICA03 and T-ICA04 caused systemic colonization (90%) of seeds followed by the occurrence of radicle and coleoptile decay. In contrast, T-ICA08 strain was less pathogenic against seed tissues (40%) in comparison to the other strains isolated. Our study showed that in transgenic insect-resistant cotton the disease "Fusarium wilt" is caused by the fungus, F. solani. Future studies are necessary to characterize the F. solani populations to determine whether phenological stages might influence the genetic diversity of the fungal populations present.

  3. Complete genome sequence of a Klebsiella pneumoniae strain isolated from a known cotton insect boll vector

    Science.gov (United States)

    Klebsiella pneumoniae (associated with bacterial pneumonia) was previously isolated from Nezara viridula, a significant vector of cotton boll-rot pathogens. We provide the first annotated genome sequence of the cotton opportunistic strain K. pneumoniae 5-1. This data provides guidance to study the...

  4. Role of the HaHOG1 MAP kinase in response of the conifer root and butt rot pathogen (heterobasidion annosum to osmotic and oxidative stress [corrected].

    Directory of Open Access Journals (Sweden)

    Tommaso Raffaello

    Full Text Available The basidiomycete Heterobasidion annosum (Fr. Bref. s.l. is a filamentous white rot fungus, considered to be the most economically important pathogen of conifer trees. Despite the severity of the tree infection, very little is known about the molecular and biochemical aspects related to adaptation to abiotic stresses. In this study, the osmotic and oxidative tolerance as well as the role of the HaHOG1 Mitogen Activated Protein Kinase (MAPK gene were investigated. The transcript levels of the yeast orthologues GPD1, HSP78, STL1, GRE2 and the ATPase pumps ENA1, PMR1, PMC1 known to have an important role in osmotolerance were also quantified under salt osmotic conditions. The HaHOG1 gene was used for a heterologous expression and functional study in the Saccharomyces cerevisiae Δhog1 strain. Moreover, the phosphorylation level of HaHog1p was studied under salt osmotic and oxidative stress. The result showed that H. annosum displayed a decreased growth when exposed to an increased concentration of osmotic and oxidative stressors. GPD1, HSP78, STL1 and GRE2 showed an induction already at 10 min after exposure to salt stress. Among the ATPase pumps studied, PMC1 was highly induced when the fungus was exposed to 0.2 M CaCl₂ for 60 min. The heterologous expression of the HaHOG1 sequence in yeast confirmed that the gene is able to restore the osmotolerance and oxidative tolerance in the S. cerevisiae hog1Δ mutant strain. The HaHog1p was strongly phosphorylated in the presence of NaCl, KCl, H₂O₂ but not in the presence of CaCl₂ and MgCl₂. The GFP-HaHog1p fusion protein accumulated in the nuclei of the S. cerevisiae hog1Δ cells when exposed to high osmotic conditions but not under oxidative stress. These results provide the first insights about the response of H. annosum to osmotic and oxidative stress and elucidate the role of the HaHOG1 gene in such conditions.

  5. Effects of cell suspension and cell·free culture filtrate of Pseudomonas aeruginosa in the control of root rot-root kont disease complex of tomato (Lycopersicon esculentum Mill.

    Directory of Open Access Journals (Sweden)

    I. A. Siddiqui

    2013-12-01

    Full Text Available The plant growth-promoting rhizobacterium Pseudomonas aeruginosa strain IE-6 was tested for antagonistic activity towards Meloidogyne javanica, the root-knot nematode and soilbome root-infecting fungi viz., Macrophomina phaseolina, Fusarium solani and Rhizoctonia solani under laboratory and greenhouse conditions. Cell-free culture filtrate of the bacterium caused significant reduction in egg hatching of M.javanica and inhibited radial growth of fungi in vitro. Cell-free culture filtrate also caused lyses in mycelium of F.solani. Under greenhouse conditions, soil drenches with the aqueous cell suspension or cell-free culture resulted in a considerable reduction in nematode population densities in soil and subsequent root-knot development due to M.javanica. In addition to nematode control, rhizobacterium application also inhibited root-infection caused by soilborne root~infecting fungi with significant enhancement of growth of tomato seedlings.

  6. Heterobasidion annosum root and butt rot of Norway spruce, Picea abies: Colonization by the fungus and its impact on tree growth

    Energy Technology Data Exchange (ETDEWEB)

    Bendz-Hellgren, M. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology

    1997-12-31

    Diameter growth losses associated with decay were quantified on a nationwide scale, and volume growth losses were measured in two stands. Diameter growth losses were 8-10% during a 5-year period in the nationwide study and 23% in one of the stands, whereas in the other stand, no volume losses could be attributed to decay. The effects of stump moisture content, temperature and time elapsed between felling and inoculation on the establishment of H. annosum spore infections in stumps were investigated among stumps resulting from thinnings and clear-cuttings. Furthermore, inoculations with H. annosum conidia were made between 0 hours and 4 weeks after thinning. The incidence of stump infections was lower on clear-cut areas than in thinned stands, but high enough to warrant stump treatment on clear-cuttings. A positive relation was found between heartwood moisture content and the proportion of heartwood infected, whereas the opposite relation was found for sapwood. The establishment of new conidiospore infections decreased with time, and it appeared that stumps were no longer susceptible to infection after 3 weeks had elapsed since felling. Roots of stumps and trees on forest land or former arable land were inoculated with H. annosum treated sawdust. The growth rate of H. annosum in roots of stumps was 25 cm/year, corresponding to 2.5 to 3 times the growth rate in tree roots. Previous land use did not affect the fungal rate of spread. Also, the average initial spread rate of H. annosum in naturally infected Norway spruce stems was estimated at 30 cm/year 156 refs, 9 figs

  7. INFLUÊNCIA DO PREPARO DE SOLO E DA ROTAÇÃO DE CULTURAS NA SEVERIDADE DE PODRIDÕES RADICULARES NO FEIJOEIRO COMUM EFFECTS OF SOIL TILLAGE SYSTEM AND CROP ROTATION ON DRY BEAN ROOT ROT SEVERITY

    Directory of Open Access Journals (Sweden)

    Pedro Marques da Silveira

    2007-09-01

    Full Text Available

    As podridões radiculares do feijoeiro são causadas pelos fungos Rhizoctonia solani Kühn e Fusarium solani f. sp. phaseoli Snyd. & Hans. Neste trabalho testou-se a combinação dos fatores preparo de solo e rotação de culturas, além de se avaliarem seus efeitos sobre as podridões radiculares do feijoeiro. Os tipos de preparo de solo consistiram em: arado+grade (P1, arado (P2, grade (P3 e plantio direto (P4. As rotações de culturas foram: arroz-feijão (R1, milho-feijão (R2, arroz/calopogônio (Calopogonium muconoides-feijão (R3 e milho-feijão-milho-feijão-arroz-feijão (R4. A severidade de F. solani f. sp. phaseoli, avaliada aos 25 dias após o plantio, apresentou interação significativa, sendo a maior severidade encontrada na combinação da rotação R3 com o preparo de solo P1, e a menor severidade, na combinação da rotação R2 com o preparo de solo P3. Diferenças estatísticas ocorreram na severidade da doença provocada por R. solani. O preparo de solo P3 apresentou maior severidade que P4, e, entre as rotações, R3 apresentou a maior severidade da doença.

    PALAVRAS-CHAVE: Rhizoctonia solani; Fusarium solani f. sp. phaseoli; práticas culturais; fungos.

    Dry bean root rot is caused by the fungi Rhizoctonia solani Kühn and Fusarium solani f. sp. phaseoli Snyd. & Hans.The effects of the interaction between soil tillage systems andcrop rotation on the severity of root rot was tested. The soiltillage systems consisted of plough+harrow (P1, plough (P2,harrow (P3 and no tillage (P4 and the crop rotation treatmentswere rice-bean (R1, corn-bean (R2, rice/Calopogonium muconoides-bean (R3 and corn

  8. Indução de resistência do mamoeiro à podridão radicular por indutores bióticos e abióticos Resistance induction to root rot in papaya by biotic and abiotic elicitors

    Directory of Open Access Journals (Sweden)

    Giltembergue Macedo Tavares

    2009-11-01

    Full Text Available O objetivo deste trabalho foi avaliar o potencial do uso de indutores de resistência bióticos e abióticos na redução da podridão radicular em mamoeiro. Mudas de mamoeiro foram pulverizadas com os fungicidas fosetil-Al, metalaxil e Mancozeb (2 g L-1, com os indutores abióticos fosfito de potássio (2,5 e 5 mL L-1, ácido salicílico 0,15 e 0,30%, Reforce (indutor comercial + ácido salicílico a 5%, acibenzolar-S-metil (ASM (0,15 e 0,30 g L-1, e com o indutor biótico Saccharomyces cerevisiae (3 e 6 mL L-1, três e seis dias antes da pulverização de 1 mL de suspensão de 10(5 zoósporos mL-1 de Phytophthora palmivora. Todos os tratamentos tiveram efeito no controle da podridão de raízes em relação à testemunha, com exceção do Reforce + ácido salicílico a 5% (3 mL L-1, seis dias antes da inoculação. Os tratamentos com ASM, com exceção da dosagem 0,15 g L-1 seis dias antes da inoculação, apresentaram resultados similares aos dos fungicidas metalaxil e Mancozeb. Plantas pulverizadas com ASM apresentaram aumento de atividade da peroxidase e beta-1,3-glucanase e maior concentração de lignina que a testemunha. No entanto, esses tratamentos não tiverem efeito sobre a atividade da quitinase. O ASM é um potencial indutor de resistência a P. palmivora em mamoeiro.The objective of this work was to evaluate the potential use of biotic and abiotic elicitors of resistance in the reduction of root rot in papaya. Papaya seedlings were sprayed with the fosetil-Al and metalaxyl and Mancozeb (2 g L-1 fungicides, with the potassium phosphite (2.5 and 5 mL L-1, salicylic acid 0.15 e 0.30%, Reforce (commercial product + salicylic acid 5%, acibenzolar-S-methyl (ASM (0.15 and 0.30 g L-1 abiotic elicitors, and with the Saccharomyces cerevisiae (3 and 6 mL L-1 biotic elicitor, applied three and six days before the inoculation with 1 mL of 10(5 zoospores mL-1 suspension of Phytophthora palmivora. All treatments were effective in controlling

  9. BvGLP1过表达增强了转基因小麦对根腐病的抗性%Expression of BvGLP1 in Transgenic Wheat Enhances Resistance to Common Root Rot

    Institute of Scientific and Technical Information of China (English)

    党良; 宿振起; 叶兴国; 徐惠君; 李钊; 邵艳军; 张增艳

    2013-01-01

    BvGLP1 is a kind of germin-like protein (GLP) from sugar beet. GLP catalyzes the oxidation of oxalic acid to produce hydrogen peroxide that induces plant defense response to pathogen and results in enhanced-resistance. The open-reading-frame sequence of BvGLP1 was synthesized and used to construct a BvGLP1 expression vector pA20-RSS1P::BvGLP1. In the vector, the expression of BvGLP1 was controlled by rice sucrose synthase-1 promoter (RSS1P). BvGLP1 was introduced into wheat vari-ety Yangmai 18 through bombardment. The presence and expression of BvGLP1 in T0 to T3 transgenic wheat plants were charac-terized by PCR, RT-PCR, and QPCR analyses. The common root rot and sharp eyespot disease tests on BvGLP1 transgenic wheat plants following artificial inoculation with the pathogens revealed that the expression of BvGLP1 in five transgenic wheat lines significantly enhanced resistance to common root rot.%  类萌发素蛋白(germin-like protein, GLP)是一类含有cupins结构域的糖蛋白,在植物基础抗性等方面起着重要作用.本研究人工合成了甜菜GLP基因BvGLP1,并利用基因重组技术构建了受韧皮部特异表达启动子RSS1P驱动的BvGLP1基因单子叶植物表达载体pA20-RSS1P::BvGLP1.通过基因枪介导法将其转入小麦品种扬麦18中,对转基因扬麦18的T0至T3代植株中BvGLP1进行了PCR、半定量RT-PCR和荧光定量QPCR检测,并对转基因小麦进行根腐病和纹枯病抗性鉴定.结果表明, BvGLP1已转入转基因小麦扬麦18,并能在转基因小麦中遗传、转录表达;5个转BvGLP1基因小麦株系的根腐病抗性比受体品种扬麦18有显著提高,说明BvGLP1过表达增强了转基因小麦对根腐病的抗性.

  10. Alternativas de control en la pudrición radical de cebolla para el Valle de la Trinidad, Baja California Control Alternatives for Onion root rot in the Trinity Valley, Baja California

    Directory of Open Access Journals (Sweden)

    Armando Pulido-Herrera

    2012-02-01

    Full Text Available La pudrición radical en cebolla es la enfermedad más importante en el Valle de la Trinidad, Baja California, México. Con el propósito de evaluar estrategias de control para la enfermedad se realizaron tres experimentos durante 2007, 2008 y 2009. En el experimento I (2007 los tratamientos fueron: 1 Tiofanato metílico; 2 Smicobac (Trichoderma + Bacillus sp. + Azospirillum sp. + Pseudomonas sp.; 3 estiércol de bovino (EB; 4 residuos de cebolla (RC; 5 solarización plástico transparente (SPT, 6 solarización plástico negro (SPN; 7 SPT + EB; 8 SPT + RC; 9 SPN + EB; 10 SPN + RC; 11 Trichodef (Trichoderma harzianum;y 12testigo. En el experimento II (2008, los tratamientos fueron los mismos excepto el tratamiento 2, sustituido porprotector (extractos vegetales; y en el experimento III (2009 los tratamientos fueron: 1 SPT + estiércol de ovino (EO; 2 SPN + EO; 3 SPT; 4 SPN; 5 control biológico (Trichoderma spp.; y 6 control químico (2- (tiocianometiltio benzotiazol 30%. Los resultados indicaron que los tratamientos solarización plástico transparente con o sin enmiendas orgánicas, presentaron incrementos significativos (p≤ 0.05 de 22 a 34% en el rendimiento y diámetro del bulbo con respecto al control biológico y químico; sin embargo, en estos dos últimos tratamientos la incidencia y severidad se redujo significativamente (p≤ 0.05, por lo que la solarización con plástico transparente y el control biológico, son alternativas viables para el control de la pudrición radical en cultivos de cebolla en Baja California, México.Onion's root rot is the most important disease in the Trinidad Valle, Baja California, Mexico. In orderto evaluate strategies to control this disease, three experiments were conducted during 2007, 2008 and 2009. In experiment I (2007 the treatments were: 1 Thiophanate methyl; 2 Smicobac (Trichoderma+Bacillus sp. + Azospirillum sp. + Pseudomonas sp.; 3 cattle manure (EB; 4 waste of onion (RC; 5 clear plastic

  11. ldentification and Control Methods of Eggplant Southern Blight, Damp-ing-off, Root Rot, Verticil-lium Wilt and Fusarium Wilt%茄子白绢病、猝倒病、根腐病、黄萎病和枯萎病的识别与防治

    Institute of Scientific and Technical Information of China (English)

    高焕; 郑丹丹

    2012-01-01

    介绍了茄子白绢病、猝倒病、根腐病、黄萎病和枯萎病的危害症状、发病特点,并从农业措施、化学防治等方面总结了各病害的综合防治方法。%The symptom and disease characteristics of eggplant southern blight, damping-off, root rot, verticillium wilt and fusarium wilt were introduced. Then the integrated control methods were put forward, which contained measures of agricultural control, chemical control and so on.

  12. Biological control of Phytophthora root rot of avocato with microorganisms grown in organic mulches Controle biológico da podridão radicular de Phytophthora no abacateiro utilizando substratos orgânicos colonizados

    Directory of Open Access Journals (Sweden)

    Jefferson L. da S. Costa

    2000-10-01

    Full Text Available Organic mulches colonized with microbial biocontrol agents, termed bioenhanced mulches, were tested for their ability to reduce Phytophthora root rot of avocado (Persea americana Mill.. Benomyl-resistant mutants of Gliocladium virens (KA 230-1 and Trichoderma harzianum (KA 159.2 isolated from suppressive soils and selected as efficient antagonists of P. cinnamomi were evaluated for their ability to colonize different mulches under controlled laboratory conditions. Sudangrass and a coarse yardwaste were found to be better substrates than a fine yardwaste, woodwaste or rice hulls for biocontrol agents propagules production. The most suitable conditions for colonization were an optimum temperature of 24°C, a moisture content of 20% for sudangrass and 30% for the coarse yardwaste, and a continuous light exposure during a 15-day incubation period. In the greenhouse, fresh sudangrass and a coarse yardwaste colonized with G. virens and used as a surface mulch proved to be the best combination for reducing the population of P. cinnamomi in 4-liter pots containing artificially-infested soil. Healthy avocado roots made up 31-37% of the roots in the G. virens-mulch combinations compared to 0% healthy in infested controls after two months.Compostos orgânicos colonizados com agentes de controle microbiológico, então denominados compostos bioativados, foram testados quanto a sua habilidadade controlar à podridão radicular de Phytophtora no abacateiro (Persea americana Mill. Mutantes de Gliocladium virens (KA 230-1 e Trichoderma harzianun (KA 159-2 resistentes a benomyl recuperados de solos supressivos e selecionados como eficientes antagonistas à P. cinnamoni foram avaliados quanto à sua capacidade de colonizar diversos compostos orgânicos em condições de laboratório. O Capim Sudão e um Composto de Jardim de alta granulação demonstraram quanto à sua capacidade de multiplicar propágulos de agentes de biocontrole, serem superiores à um

  13. Analysis of root-knot nematode and fusarium wilt disease resistance in cotton (Gossypium spp.) using chromosome substitution lines from two alien species

    Science.gov (United States)

    To Identify a new germplasm resource, and to validate chromosomal regions and favorable alleles associated with nematode and fungal disease resistance traits, a series of interspecific cotton (Gossypium spp.) chromosome substitution (CS) lines were used in this study. The CS lines were developed in ...

  14. 8种植物挥发物和浸提液对三七根腐病菌的抑制活性研究%The Study of Inhibitory Activity of Eight Plant Volatiles and Extracts to Panax notoginseng Root Rot Pathogens

    Institute of Scientific and Technical Information of China (English)

    张伟; 廖静静; 朱贵李; 张卉; 段晓龙; 朱书生; 杨敏

    2013-01-01

    The purpose of this study was to screen crops which volatiles and extracts showing antifungal activity, and use them for rotation to control Panaxnotoginsengroot rot. This study tested the inhibitory activity of 8 plant volatiles and extracts to Phytophthora cactorum and Fusarium solani, the casual agent of panax notoginseng root rot using mycelial growth rate method. The results revealed that the volatiles and extracts of Alliumsativum, A.epa, A.tuberosum, A.fistulosumshowed obvious inhibition activity against P.cactorum and F. solani and the inhibition activity of A. sativum was the strongest. The volatiles of Zingiber officinale, Houttuynia cordata, Coriandrum sativum and Mentha haplocalyx had little inhibition activity on P. cactorum and F.solani, sometimes accelerated colony growth when treated with low concentration. However, the extracts of Z.officinale, the root and leaf of C.sativumshowed distinct inhibitory activity to P.cactorumand F.solani. This data would provide scientific basis for using rotation of these crops to control Panax notoginseng root rot, achieving ecological control of Panaxnotoginsengroot rot.%筛选挥发物及浸提液具有抑菌活性的作物,用于与三七轮作防治根腐病。采用菌丝生长速率法测定了8种植物的挥发物和浸提液对引起三七根腐病的恶疫霉菌和腐皮镰孢菌的抑制活性。葱属作物大蒜、洋葱、葱及韭菜的挥发物和浸提液对恶疫霉菌和腐皮镰孢菌均具有明显的抑制效果,且大蒜挥发物和浸提液的抑菌活性最强;生姜、鱼腥草、香菜茎和薄荷的挥发物抑菌效果不明显,甚至在低浓度下出现促进菌丝生长的现象,而生姜、香菜根和叶的浸提液则表现出明显的抑菌活性。本研究结果可为利用作物轮作控制三七根腐病提供科学依据,有利于实现三七根腐病的生态防控。

  15. Identification of Fusarium Pathogens for Root Rot of Vicia faba L.at Seedling Stage in the Cold and Humid Regions of Gansu%甘肃高寒阴湿地区蚕豆苗期镰刀菌根腐病病原鉴定

    Institute of Scientific and Technical Information of China (English)

    侯思雯; 李敏权; 杨晓明; 杨发荣

    2011-01-01

    Isolation and culture of typical diseased plants of Viciafaba L. With fusarium root rot at seedling stage in the cold and humid regions of Linxia, 34 single-spore isolates of fusarium were obtained and identified, which belonged to Fusarium solani, Fusarium semitectum and Fusarium dimerum, respectively. Their pathogenicity was tested by using pot inoculation and.culture plate inoculation in laboratory. The results showed that all isolates had strong pathogenicity to seedlings of Viciafaba L., in which the Fusarium semitectum and Fusarium dimerum were the pathogens for root rot of Viciafaba L. At seedling stage is the first confirmed record.%对临夏高寒阴湿地区蚕豆苗期镰刀菌根腐病典型病株进行分离培养,共获得34个镰刀菌单孢菌株,经鉴定分别是茄镰刀菌(Fusarium solani)、半裸镰刀菌(Fusarium semitectum)和单隔镰刀菌(Fusarium dimerum).采用室内盆栽接种和平皿接种法测定致病性,结果表明,茄镰刀菌、半裸镰刀菌和单隔镰刀菌对蚕豆幼苗都有较强的致病性.其中,半裸镰刀菌和单隔镰刀菌是蚕豆苗期根腐病病原属首次报道.

  16. Diaporthaceae associated with root rot of maize

    NARCIS (Netherlands)

    Lamprecht, S.C.; Crous, P.W.; Groenewald, J.Z.; Tewoldemedhin, Y.T.; Marasas, W.F.O.

    2011-01-01

    We investigated the identity and genetic diversity of more than 100 isolates belonging to Phyllosticta (teleomorph Guignardia), with particular emphasis on Phyllosticta citricarpa and Guignardia mangiferae s.l. occurring on Citrus. Phyllosticta citricarpa is the causal agent of Citrus Black Spot and

  17. Reaction of arracacha genotypes to the root soft rot caused by Pectobacterium chrysanthemi Reação de genótipos de mandioquinha-salsa à podridão-mole das raízes causada por Pectobacterium chrysanthemi

    Directory of Open Access Journals (Sweden)

    Gilmar Paulo Henz

    2005-01-01

    Full Text Available The purpose of this paper was to screen thirty-two arracacha genotypes for their reaction to root soft rot. Twenty roots of each genotype were inoculated with two Pectobacterium chrysanthemi isolates in a randomized experiment (10 roots/isolate. After inoculation, roots were individually wrapped with PVC film and kept at 26ºC in closed plastic bags. Soft rot lesions were recorded after 36 hours and genotypes were grouped in four classes of susceptibility by cluster analysis: 10 were less susceptible, 16 intermediate, 3 susceptible and 3 very susceptible. All the tested arracacha genotypes showed only variation in the degree of susceptibility.O objetivo deste trabalho foi avaliar a reação de 32 genótipos de mandioquinha-salsa à podridão-mole das raízes. Vinte raízes de cada genótipo foram inoculadas com dois isolados de Pectobacterium chrysanthemi em um experimento casualizado (10 raízes/isolado. Após a inoculação, as raízes foram embaladas com filmes de PVC e mantidas a 26ºC em sacos de plástico. As lesões de podridão-mole foram avaliadas após 36 horas e os genótipos agrupados em quatro classes de suscetibilidade por análise de agrupamento: 10 foram menos suscetíveis, 16 intermediários, 3 suscetíveis e 3 muito suscetíveis. Todos os genótipos avaliados demonstraram apenas variação no grau de suscetibilidade.

  18. Impact of management strategies in the basal rot, charcoal rots epidemiology and Phaseolus vulgaris L. yield.

    Directory of Open Access Journals (Sweden)

    Ulacio Osorio Dilcia

    2013-02-01

    Full Text Available The effect of chemical, physical, biologycal and cultural strategies individually or combinated were evaluated in the epidemiology of the basal rot (Sclerotium rolfsii, charcoal rot (Macrophomina phaseolina and the Phaseolus vulgaris cv Tacarigua yield at Barinas state from Venezuela. In the experiment, Tebuconazole (Teb was applicated at seed (1 L/Ton and at soil, a los 30 y 60 days after of the sow (1 L/ha; Trichoderma harzianum (Tri was applicated at seed (15 g for each 1.5 k and to 15, 30, 45 y 60 days after of the sow (30 g/10 L of water. On the other hand, soil was solarizated (Sol during 15 days and calcium nitrate (Ca (60 g/10 L of water was applicated each 15 days until 60 days of growth of cultivated plants. Basal rot was registered as far as 42 days after of the sow, showing less of 5.3% in Teb y the combination SolTeb. The hightest incidence of this disease was observed in the treatment Tri with 28.5%, being highter that control (14.5%. Last to 42 days predominated the charcoal rot in the rest of the plants for a total of 100% of incidente in everything the treatments. Nevertheless, Teb showed the hightest yield with 555 k/ha, being different estatistically at treatment TriCa, which showed the lowest yield with 31 k/ha, however, the roots not formed nodules nitrogen uptake in these replications with the fungicide and Ca. It is concluded that S. rolfsii was sensible at action of some of the treatments; but not M. phaseolina; nevertheless, the plants were capables to produce seeds health apparently in treatments in which observed less severity of charcoal rot.

  19. 枯草芽孢杆菌YB5对菜豆根腐病菌的抑菌机制测定及应用%Application and Antagonistic Mechanism of Bacillus subtilis YB5 Gainst Fusarium solani Causing Green Bean Root Rot

    Institute of Scientific and Technical Information of China (English)

    赵长龙; 赵慧妍

    2016-01-01

    Fusarium root rot of bean caused by Fusarium solani f .sp . phaseoli is an important disease of this crop worldwide and has economic impact in green bean producing areas .In order to biological control ,Bacillus subtilis YB5 was a potential bacterial biocontrol agent against F .solani causing green bean root rot .And appli‐cation and antagonistic mechanism of YB5 against F .solani was tested .The results showed that secondary me‐tabolite production by YB5 could effectively inhibit mycelial growth ,spores bearing and germination of F .sola‐ni and was sensitive to high‐temperature .And YB5 bacterial suspension had no effect on green bean seeds ger‐mination and could encourage root development .YB5 secondary metabolite and bacterial suspension could ef‐fectively protect green bean against root rot caused by F .solani .And its control effect was up to 94 .6% by potted plant experiments .%腐皮镰孢引起的菜豆根腐病是一种世界性病害,在菜豆生产中危害严重。为对其有效的生物防治,针对菜豆根腐病利用枯草芽孢杆菌进行了拮抗机制及应用的研究。结果表明:YB5能有效抑制菌丝生长、孢子产生和萌发。YB5的无菌滤液对高温敏感。YB5菌液对种子发芽没有抑制作用,且能促进根系的发育。YB5菌液及无菌滤液对菜豆腐皮镰孢根腐病的盆栽均具有较好的防效,YB5菌液防效可达94.6%。

  20. Antagonism of Trichoderma spp.to Fungi Caused Root Rot of Sophora tonkinensis%木霉菌对山豆根根腐病菌的拮抗作用

    Institute of Scientific and Technical Information of China (English)

    覃柳燕; 蒋妮; 唐美琼; 缪剑华; 李林轩

    2011-01-01

    目的:研究木霉菌对山豆根根腐病菌茄腐镰孢S9(Fusarium solani)的拮抗作用,探讨生物防治菌在防治中药材土传病害上的应用前景.方法:采用生长速度法、对峙培养法研究哈茨木霉H2(Trichoderma harsianum)、绿色木霉M6(Trichoderma viride)和康宁木霉K1(Trichoderma koningii)对山豆根根腐病菌S9的拮抗作用,并讨论了其作用机理.结果:发现H2、M6竞争优势显著,生长速度分别是S9的1.43~2.72倍和1.43~1.95倍;K1的空间竞争优势较弱,生长速度不如S9.3种木霉菌对S9均有不同程度的拮抗作用,其中,M6和H2对S9的拮抗作用较强,即使在提前3 d接入病原菌的情况下,M6和H2对S9的抑制率仍能分别达100%和82.35%,拮抗系数均达Ⅰ级;K1对S9的抑制率为46.36%,拮抗系数为Ⅳ级.在显微镜下观察到木霉菌通过缠绕、寄生等方式使S9发生菌丝断裂、缢缩、消解等现象.结论:哈茨木霉和绿色木霉作为生防菌在防治中药材土传病害上具有深入开发的前景.%Objective:To study the antagonism of Trichoderma spp. to fungi S9 ( Fusarium solani)which caused root rot of Sophora tonkinensis and discuss the further develop prospects of microbial biological control in soil-borne diseases on Chinese herbal medicines. Methods:Antagonism of H2 (Trichoderma harsianum ) , M6 (Trichoderma viride ) and K1 (Trichoderma koningii ) to Fusarium solani were researched by growth rate and confront culture. And their mechanisms were discussed. Results: H2 and M6 had obvious competitive advantage, the growth rate of which were 1.43 ~ 2. 72 times and 1.43 ~ 1.95 times as S9 respectively. The space competitive advantage of K1 was relatively weak ;the growth rate was slower than S9. The antagonism of three species of Trichoderma spp. to S9 was in varying degrees. The antagonism to S9 of M6 and H2 was better,the inhibition rate were 100% and 82. 35% respectively,even cultivated S9 for three days in advance. And their

  1. Toxicity Assay of Several Chemical Fungicides Against Pathogen of Wheat Root Rot%6种杀菌剂对小麦叶斑根腐病菌的毒力测定

    Institute of Scientific and Technical Information of China (English)

    袁胜亮; 刘峰; 张娜

    2011-01-01

    Screening and management of high performance chemical fungicide was the important way to control wheat disease caused by Bipolaris sorokiniana. Suitable fungicide used in the field could be sreened by virulence testing in laboratory. The inhibition of 6 kinds of fungicides on B. sorokiniana, the phynotype of wheat root rot, was studied using biometric methods in this study. The results showed that different fungicides on colony growth was different, in which Difenoconazole was the most effective one to the pathogen, 94.9%inhibition rate was obtained when the concentration was 40 mg/L. Metiram, Propineb, Thiram, Carbendazim and Mancozeb were effective in mm, with the inhibition rate of 89.5%, 86.3%, 48.2%, 40% and 37.8%,respectively. Strong inhibition of spore germination was also displayed with Difenoconazole, hemi-inhibitory concentration was 6.45 mg/L, showed that this agent can be used in production continuously.%筛选高效的防治药剂并研究出其配套的田间防治应用技术是防治小麦根腐病的重要措施,而通过不同杀菌剂对病原菌的毒力测定分析,可为田间防治药剂的筛选提供重要的参考依据.此研究采用生物测定的方法,研究了6种化学药剂对小麦叶斑根腐病菌菌丝生长的抑制作用.结果表明,不同药剂对病原菌生长的影响不同,世高对菌丝生长的抑制作用最显著,在质量浓度为40 mg/L时抑制率达94.9%;其次为唑醚-代森联、丙森锌、福美双、多菌灵和代森锰锌,在该浓度下对菌丝生长抑制率依次为89.5%、86.3%、48.2%、40%和37.8%.对病原菌菌丝生长抑制效果最好的世高对病原菌孢子萌发同样具有强烈的抑制作用,抑制萌发中浓度为6.45 mg/L,可在生产中继续合理使用.

  2. Naturally Colored Cotton

    Institute of Scientific and Technical Information of China (English)

    履之

    1994-01-01

    Instead of using dye to color cotton, an Arizona cotton breeder is letting nature do the work. Through crossbreeding, Sally Fox of Natural Cotton Colours in Wickenberg is creating plants that yield fiber in an array

  3. Gene cloning: exploring cotton functional genomics and genetic improvement

    Institute of Scientific and Technical Information of China (English)

    Diqiu LIU; Xianlong ZHANG

    2008-01-01

    Cotton is the most important natural fiber plant in the world. The genetic improvement of the quality of the cotton fiber and agricultural productivity is imperative under the situation of increasing consumption and rapid development of textile technology. Recently, the study of cotton molecular biology has progressed greatly. A lot of specifically or preferentially expressed cotton fiber genes were cloned and analyzed. On the other hand, identification of stress response genes expressed in cotton was performed by other research groups. The major stress factors were studied including the wilt pathogens Verticillium dahliae, Fusarium oxy-sporum f. sp. vasinfectum, bacterial blight, root-knot nematode, drought, and salt stress. What is more, a few genes related to the biosynthesis of gossypol, other sesquiterpene phytoalexins and the major seed oil fatty acids were isolated from cotton. In the present review, we focused on the major advances in cotton gene cloning and expression profiling in the recent years.

  4. Field Efficiency Trial of 72% Streptomycin against Konjac Bacterial Soft Rot

    Institute of Scientific and Technical Information of China (English)

    Huang; Yongsheng; Li; Xiaojun; Zhu; Shijin; Ma; Yongsheng; Wang; Li

    2014-01-01

    72% Streptomycin soluble powder was used to control konjac bacterial soft rot in the study. The control efficiency and yield of different treatments were investigated,and the benefit was analyzed. The control scheme against konjac bacterial soft rot was as follows: spraying 72% atreptomycinon twice on rotation fields after all the seedlings were strong and uniform,or irrigating roots with 72% atreptomycinon once and spraying twice on continuous cropping fields.

  5. Survey and Comprehensive Prevention of Root Knot Nematode Disease on Cotton in South Area of Hainan Island%海南岛南繁区棉花根结线虫病发生情况调查及综合防治

    Institute of Scientific and Technical Information of China (English)

    符美英; 芮凯; 符尚娇; 陈绵才

    2015-01-01

    Investigation cotton root knot nematode disease in Hainan island with 5 point method, and collecting of cotton root knot nematode. Nematodes were identified by using the methods of morphology observation and isozyme analysis. The result shows (1)Through of the survey, cotton root knot nematode disease was found incidence was 40%, and the incidence degree up to level 3, index of root knot up to 29 in two farms. (2) Nematodes were identified as Meloidogyne incognita. Agricultural control, biological control, physical control and chemical control combination was used to controlling for cotton root knot nematode disease of preliminary.%用5点法调查海南岛南繁区棉花根结线虫病,并采集棉花根结线虫病样本。运用形态学观察和同工酶分析鉴定棉花根结线虫。结果表明:(1)南繁区的南滨农场和师部农场的棉花根结线虫病发病率达40%,发病程度最高为3级,根结指数最高为29;(2)鉴定该棉花根结线虫为南方根结线虫。初步提出棉花根结线虫病的防治方法主要是农业防治、生物防治、物理防治和化学防治相结合的综合防治方法。

  6. Zero Tillage cotton systems and soil quality

    Science.gov (United States)

    Landers, J. N.; de Freitas, P. L.

    2012-04-01

    Monocropping in cotton production systems negates the benefits of zero tillage. With cotton in a 3-year rotation including other summer and cover crops, such as soybeans and intensive-rooting Brachiaria spp., research on sandy soils in Bahia improved soil fertility, structure and biological activity. Cotton is a deep tap-rooted crop, sensitive to physical and chemical impediments to root development; this has engendered a paradigm of heavy soil preparation operations to remove these. But, ZT can overcome such obstacles, allowing the cotton crop to benefit from cost reductions and a number of other benefits, especially erosion control.. Soil quality has three principal dimensions. Maximum yields only occur when soil fertility, structure and biological activity are in balance. Under Zero Tillage management of Brazilian soils, the processes of nutrient availability, nutrient cycling and efficiency result from increasing SOM and higher CEC. ZT system fertility is also strongly influenced by total annual aerial and root biomass generation; C:N ratios of the biomass, changes in aeration in residue breakdown processes (for roots, dependent on internal drainage), reduced fixation of Phosphorus fertilizers, the possibility of surface application of P and K, use of deep-rooted cover crops to re-cycle nutrients and deleterious effects of over-liming. Soil physical parameters undergo a transformation : greater water holding capacity, a small increase in bulk density (ameliorated by a reversal of soil aggregate breakdown inherent to conventional tillage by the binding action of root exudates and fungal hyphae), enhanced particle aggregate size protects SOM from oxidation; old root holes create semi-permanent macro-pores which facilitate rooting, aeration and rainfall infiltration.. Soil life of all types benefits from ZT management and contributes to soil fertility and structural improvements, plus enhancing certain biological controls of pathogenic organisms and allelopathic

  7. 朝鲜蓟细菌性根茎腐烂病病原的分离与鉴定%Isolation and identification of bacterial pathogen causing stem and root rot on artichoke

    Institute of Scientific and Technical Information of China (English)

    王晓丽; 夏花; 张平喜; 朱宏建; 高必达

    2012-01-01

    A new disease on globe artichoke (Cynara scolymus L.) was observed in commercial fields in Changde, Hunan Province, China. Typical symptoms were wilting and necrosis from the outermost leaves, dark brown discoloration of the vascular tissue and pith of main stem. Eventually, the plants wilted and died. Manual weeding and cuttings often led to the development of typical soft rot during propagation. To investigate the causal agent of the disease, isolations were made from rotted stems of field artichoke plants on nutrient agar (NA). Bacteria consistently isolated from the diseased tissues formed grey-white, glossy, convex, translucent, and round colonies on NA. The bacterial cells were gram-negative rods with 2 to 8 peritrichous flagclla and rounded ends under the microscope. In artificial inoculation test, these isolates could also cause stem rot of Chinese cabbage, pepper, lettuce and artichoke, and slice rot of carrot, tomato and potato within 48 h at 28t!. The results demonstrated that these isolates are causative agent of soft-rot disease. PCR amplification was carried out by utilizing universal 16S rDNA primer pair 16SF/16SR and pel gene primers Y1/Y2. The 16S rDNA and pel gene sequences of isolate HNXDT002 (GenBank accessions JF721958 and JF721960, respectively) had 99% and 93% nucleotide identity with strains of Pectobacterium carotovorum subsp.carotovorum (GenBank accessions U80197 and CP001657, respectively). It came to the conclusion that the causal agent of soft-rot disease on artichoke belonged to Pectobacterium carotovorum subsp. carotovorum.%在湖南省常德市西洞庭管区种植的朝鲜蓟(Cynara scolumus L.)上发现了一种新的病害,其症状表现为地上部分从外层叶片开始逐步枯萎,随后根部和主茎杆的髓部腐烂变褐,最后整株枯萎.从田间感病朝鲜蓟茎杆的病健交界处用NA 培养基分离,获得10个菌株,分别指定为HNXDT001~010,并进行了致病性测定、形态观察和细

  8. Influence by physical properties of coal combustion residues (CCRs on dry root productivity of Withania somnifera grown in black cotton soil

    Directory of Open Access Journals (Sweden)

    Bhisham Yadav

    2013-05-01

    Full Text Available In India, presently ~40% Coal Combustion Residues (CCRs generated by burning of pulverized coal at Thermal Power Station is being used for cement, bricks, land reclamation etc. Now a day it has also been considered for agriculture applications. This study, an attempt was made to use of CCRs as soil modifier and micro fertilizer for cultivation of Withania somnifera under two cropping. Results revealed that production of dry root yields of Withania somnifera was found higher in T5 treatment (35.545g and 39.002g per plant as compared to control treatment (T1. It is showed significant (p<0.001% from all the treatments in both the years. The essential elements like Cu, Zn, Fe and Mn were found increasing trends in dry root of Withania somnifera with increase the concentration of CCRs application. This study is found the bulk utilization of CCRs for cultivation of Withania somnifera improved their root yield and chemical quality.

  9. Effect of Water Stress on Root Vigor and Leaf Physiology of Cotton under Mulch Drip Irrigation%水分胁迫对覆膜滴灌棉花根系活力和叶片生理的影响

    Institute of Scientific and Technical Information of China (English)

    杨传杰; 罗毅; 孙林; 甘容; 吉力力·阿不都外力; 张艳

    2012-01-01

    采用田间试验法,分析不同程度水分胁迫条件下棉花花铃期根尖根系活力、叶片叶绿素、脯氨酸和丙二醛含量变化,并对叶片脯氨酸、丙二醛含量和根系活力与土壤含水率进行相关性分析。试验以60 cm土层田间持水量的105%、100%、95%、90%、85%、80%为灌溉上限,共设6个灌水梯度,即5 400、4 950、4 500、3 750、2 850m3/hm2和2 550 m3/hm2。结果表明:单株叶片干重及叶面积、地上部干生物量、株高、叶绿素含量随灌水量的减少而降低,根冠比随灌水量的减少而增加。脯氨酸及丙二醛含量随灌水量的降低而升高,且与土壤含水率呈负相关关系,相关系数(r)分别为-0.704和-0.667;根系活力随灌水量的降低而降低,与土壤含水率呈正相关关系,其相关系数为0.67。当灌水上限为95%,即灌水量为4 500 m3/hm2时,作物表现出轻微的水分胁迫,随灌溉量的继续降低,胁迫加重。植物体内脯氨酸、丙二醛含量及根系活力与土壤含水率的相关关系在一定程度上可以用来表征棉花受干旱程度,可为棉花的灌溉管理提供参考依据。%Water stress is one of the most important abiotic stresses. A field experiment was conducted to evaluate the growth and physiological response of cotton plants to soil moisture stress under mulch drip irrigation. The total irrigation volumes of 5 400, 4 950, 4 500, 3 750, 2 850 and 2 550 m^3/hm^2 were designed for each treatment ac-cording to the upper irrigation limits of 105% , 100% , 95% , 90% , 85% and 80% of field capacity, respectively. Differences in root vigor, chlorophyll, proline and malondialdehyde (MDA) contents were tested at cotton flores- cence and boll stage so as to reveal the physiological response of cotton plants to soil moisture stress. The relation- ships between soil moisture content and the praline and MDA contents as well as root vigor were analyzed. The re-sults showed that the biomasses of dry

  10. Smart textiles: Tough cotton

    Science.gov (United States)

    Avila, Alba G.; Hinestroza, Juan P.

    2008-08-01

    Cotton is an important raw material for producing soft textiles and clothing. Recent discoveries in functionalizing cotton fibres with nanotubes may offer a new line of tough, wearable, smart and interactive garments.

  11. Comparative Analysis of Discovery Function of Cotton Future Price among Different Regions——A Case Study of Xinjiang

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Through comparative analysis, We research the relationship between cotton future price and cotton spot price in different regions, in order to formulate corresponding strategies in different regions under the new situation. We use ADF unit root test, E-G two-step cointegration test, Granger causality test, and other research methods in Eviews 5.0 statistical software, to empirically study the relationship between the cotton future price and cotton spot price in Xinjiang, the relationship between the cotton future price and cotton spot price in China. The results show that there is a long-term relationship between the cotton future price and cotton spot price in Xinjiang, between the cotton future price and cotton spot price in China; the cotton future price plays unidirectional role in guiding cotton spot price in Xinjiang and cotton spot price in China. The discovery function of cotton future price plays much greater role in the cotton market of China than in the cotton market of Xinjiang.

  12. Effects of NaCl Stress on Antioxidative System of Cotton Seedling Roots%NaCl胁迫对棉花幼苗根系抗氧化系统的影响

    Institute of Scientific and Technical Information of China (English)

    史华平; 胡晓丽; 王计平

    2016-01-01

    旨在探讨不同棉花品种在苗期的耐盐性.试验以6个不同熟性棉花品种为试材,采用溶液培养法,研究了0.3% NaC1胁迫处理24、48、72 h对棉花幼苗根系膜脂过氧化、质膜完整性、活性氧含量及抗氧化酶活性等生理生态指标的影响.结果表明:NaC1胁迫处理24 h对棉花幼苗根系细胞膜完整性及活性氧的积累几乎没有显著影响,而处理48~72h后活性氧积累显著增加,膜脂过氧化程度增强,细胞膜完整性被破坏;丙二醛的累积及膜相对透性增加进一步被希夫试剂染色和伊文斯蓝染色所证明.通过对6项生理指标进行综合评价,结果显示:0.3% NaC1胁迫处理72h后,不同品种棉花幼苗根系耐盐性由高到低依次为:‘N181’>‘N52’>‘N177’>‘K-1’>‘N203’>‘中50’.%The purpose of this study was to identify the salt tolerance of different cotton varieties in seedling stage.Solution culture experiments were carried out to study the effects of 0.3% NaCl stress treatment for 24 hours,48 hours and 72 hours on the physiological and ecological indexes of six cotton varieties' seedling,including lipid peroxidation,membrane integrity,reactive oxygen species (ROS) accumulation and antioxidant enzyme activity of roots.The results showed that there was no significant difference of membrane integrity and ROS accumulation in seedlings treated with NaC1 for 24 hours.NaCl stress treatment for 48-72 hours significantly accelerated ROS accumulation,increased membrane lipid peroxidation and destroyed membrane integrity of seedlings.The malondialdehyde accumulation and membrane relative permeability increase were proved by Schiff's reagent and Evans blue.The synthetic assessment of the six parameters indicated that under 0.3% NaCl stress for 72 hours,the order of salt tolerance of different cotton varieties was ‘N181’ > ‘N52’ >‘N177’ > ‘K-1’ > ‘ N2O3’ > ‘Zhong50’.

  13. Avaliação de progênies de algodoeiro para resistência à broca-da-raiz Progeny evaluation for resistance to the root borer in cotton

    Directory of Open Access Journals (Sweden)

    Imre Lajos Gridi-Papp

    1996-01-01

    Full Text Available Com base nos resultados de seleção, obtidos pela equipe de melhoramento do algodoeiro do Instituto Agronômico (IAC, numa gleba naturalmente infestada pela broca-da-raiz, Eutinobothrus brasiliensis (Hambleton, da Estação Experimental de Tietê, em 1966-81, três índices de avaliação foram propostos para a resistência dessa planta à praga. O coeficiente de correlação simples entre as duas repetições dos testes anuais de progênies foi adotado como parâmetro para estudar a eficiência dos índices na seleção de progênies resistentes. Pelo estudo comparativo, escolheu-se, como o mais adequado, o índice obtido pela contagem de furos (galerias observados na parte lenhosa, em corte oblíquo dos caules das plantas, feito na região do colo, no meio da parte hipertrofiada. Apresentam-se os coeficientes de correlação de 1972-81 e a discussão sobre a eficiência do índice escolhido que proporcionou, durante o período, um aumento gradual do coeficiente de correlação, significando um provável acúmulo de genes favoráveis à resistência nas progênies selecionadas. A prática de picar e enterrar a parte infestada dos caules, após a colheita dos dados, contribuiu para manter alta infestação da área pela broca. Aplicado, posteriormente, à avaliação de linhagens do programa de melhoramento do algodoeiro, o índice permitiu melhorar 50% o nível geral de resistência das linhagens em estudo.To evaluate cotton resistance to the Brazilian root borer, Eutinobothrus brasiliensis (Hambleton, three indexes were proposed, based on selection data obtained in progeny tests, on a naturally infested plot, situated at the Tietê Experiment Station, in the years of 1966 to 1981, by the cotton breeders of the Instituto Agronômico, State of São Paulo, Brazil. The simple correlation coefficient between the two repetitions of the yearly tests was used as a parameter to study the efficiency of the indexes in selecting resistant progenies

  14. Cotton Trip in China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    From September 6th to 12th,a National Cotton CouncilCotton Council International 2010 China leadership team,led by Charles Parker,Vice Chairman of NCC,visited China to see its cotton industrial development and continue building a good relationship with U.S.raw cotton’s largest consumer.

  15. World Collection of Cotton

    Institute of Scientific and Technical Information of China (English)

    KHAKIMJON Saydaliyev; ALISHER Amanturdiev; MALOXAT Halikova

    2008-01-01

    @@ Achievements of selection and other theoretical researches on cotton not only in our country,but also world-wide depend on the presence of genetic resources.Uzbek Scientific Research Institute of Selection and Seed Growing of Cotton is a leading center of science on breeding and production of cotton across Central Asia.

  16. Cotton Pricing Discussion

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Cotton prices have received a lot of attention recently.Cotton Incorporated especically designed this Special Edition of Supply Chain Insights to frame the discussion concerning prices throughout the cotton supply chain in terms of the cyclical events that contributed to recent volatility and how a return to long-term averages over time can be expected.

  17. Dictionary of Cotton

    Science.gov (United States)

    The Dictionary of Cotton has over 2,000 terms and definitions that were compiled by 33 researchers. It reflects the ongoing commitment of the International Cotton Advisory Committee, through its Technical Information Section, to the spread of knowledge about cotton to all those who have an interest ...

  18. Identification of the pathogen isolated from root rot of Taxus chinensis var.mairer and screening of its antagonistic Bacillus%南方红豆杉根腐病病原及其拮抗芽胞杆菌的鉴定

    Institute of Scientific and Technical Information of China (English)

    谯天敏; 罗蓉; 朱天辉

    2015-01-01

    In this study,the pathogen isolated from root rot of Taxus chinensis var.mairer was first indentified. Based on morphological characteristics,pathogenicity and rDNA ITS sequence analysis,the results showed that the pathogen of root-rot disease of T .chinensis var.mairer was Fusarium oxysporum .The tablet confrontation training method was adopted to screen the antagonistic Bacillus species from the healthy plant rhizosphere,and three strains with obvious antagonistic effect were obtained,namely YB6,YB1 5 and YB37.Through morphologi-cal,physiological,biochemical and 1 6S rDNA homology analysis as well as the construction of 1 6S rDNA phy-logenetic tree,we found that YB6,YB15 and YB37 were Bacillus cereus ,B .amyloliquefaciens and Paenibacillus poly-myxa ,respectively.The antagonistic effect of P .polymyxa was the best with further research and development potential. This study provides some valuable information for effective prevention and treatment of this disease.%经形态学特征观察、致病性测定及 rDNA-ITS 序列分析,首次确定红豆杉根腐病病原为尖孢镰刀菌(Fusari-um oxysporum )。采用平板对峙培养法从健康植株根际土壤中筛选得到3株对尖孢镰刀菌具有明显拮抗作用的芽胞杆菌 YB6、YB15、YB37。经形态学、生理生化及16S rDNA 同源性分析,并通过构建16S rDNA 系统发育树,将YB6、YB15和 YB37分别鉴定为蜡样芽胞杆菌(Bacillus cereus )、解淀粉芽胞杆菌(B .amyloliquefaciens )和多黏类芽胞杆菌(Paenibacillu polymyxa ),其中多黏类芽胞杆菌拮抗效果最好,具有进一步研究开发的潜力。本研究通过对南方红豆杉根腐病病原鉴定及其拮抗芽胞杆菌的筛选,对该病的防治提供了理论依据。

  19. Preparation of Algae Agents forS. miltiorrhiza Bunge Root Rot BiocontrolBacillus subtilis2-1%丹参根腐病生防芽孢杆菌2-1海藻菌剂的研制

    Institute of Scientific and Technical Information of China (English)

    周莹; 袁孟娟; 韩军; 陈芳

    2015-01-01

    With algae residue as carrier,S. miltiorrhiza bunge root rot biocontrol agents:Bacillus subtilis2-1(CGMCC No.9256), were developed into algae agents, which features both nutritional and cell biological control function, also in line with the basic indicators of agricultural products, technical indicators microbial agents. Then appropriate ratio of seaweed broth and residue was chosen by physical means. Besides, the number of viable cells, moisture content, pH value and expiration date were measured by agricultural product quality testing methods, and field experiments was conducted to test biocontrol effect. Results showed that number of effective viable agents was 2.32×109/g, moisture content was 6.75%, pH value was 6.7, and the expiration date was about 11.6 months , all of which were in line with the technical specifications of the particles. The incidence of root rot in field trials rate decreased 37.6% compared with the blank control group, the effect of biocontrol was obvious.%以海藻渣为载体,菌种为丹参根腐病生防菌:枯草芽孢杆菌Bacillus subtilis2-1(已保存CGMCC No.9256),研制成的海藻菌剂兼具营养及生物防治功能,同时菌剂的基本指标符合农用微生物菌剂产品的技术指标。用物理方法选择菌种发酵液与海藻渣混合的最佳配比,结合农用微生物菌剂产品质量检测方法对菌剂中有效活菌数、含水量、pH值及有效期进行测定,并进行大田试验,测试生防效果。菌剂有效活菌数为2.32×109/g,含水量为6.75%,pH值为6.7,常温下有效期约为11.6个月,均符合颗粒菌剂的技术指标,大田试验中根腐病的发病率比空白对照组降低37.6%,生防效果较为显著。

  20. Somatic embryogenesis in wild relatives of cotton (Gossypium Spp.)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Wild cotton species can contribute a valuable gene pool for agronomically desirable cultivated tetraploid cultivars. In order to exploit diploid cotton a regeneration system is required to achieve transformation based goals. The present studies aimed at optimizing the conditions for regeneration of local varieties as well as wild species of cotton. Different callus induction media were tested with varying concentrations of hormones in which sucrose was used as nutritional source. Different explants (hypocotyls, cotyledon, root) were used to check the regeneration of both local cotton plants and wild relatives using T & G medium,BAP medium, CIM medium, EMMS medium, and cell suspension medium. Different stages of embryogenicity such as early torpedo stage, late torpedo stage, heart stage, globular stage and cotyledonary stage were observed in wild relatives of cotton. The results of this study pave the way for establishing future transformation methods.

  1. Integrated metabolomics and transcriptomics reveal enhanced specialized metabolism in Medicago truncatula root border cells.

    Science.gov (United States)

    Watson, Bonnie S; Bedair, Mohamed F; Urbanczyk-Wochniak, Ewa; Huhman, David V; Yang, Dong Sik; Allen, Stacy N; Li, Wensheng; Tang, Yuhong; Sumner, Lloyd W

    2015-04-01

    Integrated metabolomics and transcriptomics of Medicago truncatula seedling border cells and root tips revealed substantial metabolic differences between these distinct and spatially segregated root regions. Large differential increases in oxylipin-pathway lipoxygenases and auxin-responsive transcript levels in border cells corresponded to differences in phytohormone and volatile levels compared with adjacent root tips. Morphological examinations of border cells revealed the presence of significant starch deposits that serve as critical energy and carbon reserves, as documented through increased β-amylase transcript levels and associated starch hydrolysis metabolites. A substantial proportion of primary metabolism transcripts were decreased in border cells, while many flavonoid- and triterpenoid-related metabolite and transcript levels were increased dramatically. The cumulative data provide compounding evidence that primary and secondary metabolism are differentially programmed in border cells relative to root tips. Metabolic resources normally destined for growth and development are redirected toward elevated accumulation of specialized metabolites in border cells, resulting in constitutively elevated defense and signaling compounds needed to protect the delicate root cap and signal motile rhizobia required for symbiotic nitrogen fixation. Elevated levels of 7,4'-dihydroxyflavone were further increased in border cells of roots exposed to cotton root rot (Phymatotrichopsis omnivora), and the value of 7,4'-dihydroxyflavone as an antimicrobial compound was demonstrated using in vitro growth inhibition assays. The cumulative and pathway-specific data provide key insights into the metabolic programming of border cells that strongly implicate a more prominent mechanistic role for border cells in plant-microbe signaling, defense, and interactions than envisioned previously.

  2. American Cotton Development Strategy

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The 30th International Cotton Conference took place March 24 - 27 in the historic city of Bremen,Germany this year.Worldwide high-ranking experts from cotton production, trade,spinning,weaving and some other fields of textile industries gathered together in the Bremen Town Hall.Allen A.Terhaar,Executive Director of Cotton Council International(CCI), Washington,presented a speech on the future development strategy of American cotton industry,and the development schedule in Chinese market.In the following part,let’s share his opinions and foresighted views.

  3. American Cotton Development Strategy

    Institute of Scientific and Technical Information of China (English)

    Wang Ting

    2010-01-01

    @@ When we celebrated 2009 as the International Year of Natural Fiber, the global cotton industry joined hands in bringing recognition to cotton and all natural fibers. As we move into 2010 and beyond we must continue to engage the global consumer with messages that highlight the natural, renewable and biodegradable benefits of our product However, we must also go beyond what nature has provided and work toward true sustainability throughout the cotton supply chain. If some major brands and suppliers cannot achieve "sustainability" with cotton, they will do so with other fibers.

  4. [Determination of cotton content in cotton/ramie blended fabric by NIR spectra and variable selection methods].

    Science.gov (United States)

    Sun, Tong; Geng, Xiang; Liu, Mu-hua

    2014-12-01

    Rapid detection of textile fiber components is very important for production process of quality control, trading and market surveillance. The objective of this research was to assess cotton content in cotton/ramie blended fabric quickly by near infrared (NIR) spectrum technology and variable selection methods. Reflectance spectra of samples were acquired by a NIRFlex N-500 Fourier spectroscopy in the range of 4000~10,000 cm(-1), primary election of spectral range and pretreatment analysis were conducted first. Then, three variable selection methods such as UVE (uninformative variables elimination), SPA (successive projections algorithm) and CARS (competitive adaptive reweighted sampling) were used to select sensitive variables. After that, PLS (partial least squares) was used to develop calibration model for cotton content of cotton/ramie blended fabric, and the best calibration model was used to predict cotton content of samples in prediction set. The result indicates that range of 4052~8000 cm(-1) is optimal spectral range for cotton content modeling. CARS method is an efficient method to improve model performance, the correlation coefficient and root mean square error of CARS-PLS for calibration and prediction sets are 0.903, 0.749 and 8.01%, 12.93%, respectively. So NIR spectra combined with CARS method is feasible for assessing cotton content in cotton/ramie blended fabric, and CARS method can simplify model, improve model performance.

  5. Isolation and Identification of Antagonistic Bacterium Strain JK-7Against the Pathogenic Fungi Causing Mulberry Root Rot Disease%桑树根腐病真菌病原拮抗细菌JK-7的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    张艳东; 曹梦琪; 王俊; 王凯旋; 孙国霞; 吴福安

    2013-01-01

    Mulberry root rot is a soil-borne infectious disease in mulberry root. In order to implement biological control a-gainst mulberry root rot disease, 84 strains of Bacillus were isolated from mulberry rhizospheric soil. A Bacillus strain which has antagonistic activity against Fusarium solani strain FS-1, the pathogenic fungi causing mulberry root rot disease, was screened by confrontation culture method and numbered as JK-7. The colonial morphology of strain JK-7 on LB medium was translucent, smooth and waxy on surface, and irregular at edge. Strain JK-7 is a Gram positive bacterium, rod-shaped and 0. 5 ~0. 7 μm ×1. 0 ~1. 2 μm in size. The oval-shaped spores located on middle or sub-terminal of bacterium. This strain could make use of starch and tyrosine. Its parasporal crystal was determined to be negative and reaction with peroxidase was positive. 16S rDNA sequence of strain JK-7 was amplified by PCR using a pair of bacterial universal primers and the obtained fragment size was 1 477 bp. Phylogenetic tree revealed that strain JK-7 had the closest genetic relationship with Bacillus cereus. Taken together, strain JK-7 was identified as Bacillus cereus. Plate confrontation test showed that strain JK-7 had inhibitory effect on hypha growth of pathogenic strain FS-1. Scanning electron microscopic observation indicated that strain JK-7 colonized on the surface of hyphae of FS-1, and caused deformity and breakage of mycelia, showing antagonistic effect to FS-1.%桑树根腐病是一类土壤传染性桑树根部病害.为了实施对这类病害的生物防治,从桑树根际土壤分离到84株芽孢杆菌,通过对峙培养法从中筛选出一株对桑树根腐病真菌病原腐皮镰刀菌(Fusarium solani)FS-1具有拮抗作用的菌株,将该菌株编号为JK-7.JK-7菌株在LB培养基上的菌落呈半透明、光滑蜡状,边缘不规则;为革兰阳性菌,杆状,大小0.5~0.7μm×1.0~1.2 μm,芽孢呈椭圆形,位于菌体中部或亚末端;菌株能

  6. ldentification and Control Methods of Eggplant Bacterial Wilt, Soft Rot, Necrotic Leaf Spot, Mo-saic Virus, Root-knot Ne-matode Disease, Sun-scald, Leaf Scorch and Dehiscent Fruit%茄子青枯病、软腐病、细菌性褐斑病、病毒病、根结线虫病、日灼病、叶烧病和裂果的识别与防治

    Institute of Scientific and Technical Information of China (English)

    郑丹丹; 张杨林

    2012-01-01

    介绍了茄子青枯病、软腐病、细菌性褐斑病、病毒病、根结线虫病、日灼病、叶烧病和裂果的危害症状、发病特点,并从农业措施、化学防治等方面总结了各病害的综合防治方法。%The symptom and disease characteristics of eggplant bacterial wilt, soft rot, necrotic leaf spot, mosaic virus, root-knot nematode disease, sunscald, leaf scorch and dehiscent fruit were in-troduced. Then the integrated control methods were put forward, which con-tained measures of agricultural control, chemical control and so on.

  7. Host Specialization in the Charcoal Rot Fungus, Macrophomina phaseolina.

    Science.gov (United States)

    Su, G; Suh, S O; Schneider, R W; Russin, J S

    2001-02-01

    ABSTRACT To investigate host specialization in Macrophomina phaseolina, the fungus was isolated from soybean, corn, sorghum, and cotton root tissue and soil from fields cropped continuously to these species for 15 years in St. Joseph, LA. Chlorate phenotype of each isolate was determined after growing on a minimal medium containing 120 mM potassium chlorate. Consistent differences in chlorate sensitivity were detected among isolates from different hosts and from soil versus root. To further explore genetic differentiation among fungal isolates from each host, these isolates were examined by restriction fragment length polymorphism and random amplified polymorphic DNA (RAPD) analysis. No variations were observed among isolates in restriction patterns of DNA fragments amplified by polymerase chain reaction covering the internal transcribed spacer region, 5.8S rRNA and part of 25S rRNA, suggesting that M. phaseolina constitutes a single species. Ten random primers were used to amplify the total DNA of 45 isolates, and banding patterns resulting from RAPD analysis were compared with the neighbor-joining method. Isolates from a given host were genetically similar to each other but distinctly different from those from other hosts. Chlorate-sensitive isolates were distinct from chlorate-resistant isolates within a given host. In greenhouse tests, soybean, sorghum, corn, and cotton were grown separately in soil infested with individual isolates of M. phaseolina that were chosen based on their host of origin and chlorate phenotype. Root colonization and plant weight were measured after harvesting. More colonization of corn roots occurred when corn was grown in soil containing corn isolates compared with isolates from other hosts. However, there was no host specialization in isolates from soybean, sorghum, or cotton. More root colonization in soybean occurred with chlorate-sensitive than with chlorate-resistant isolates.

  8. Endophytic Trichoderma gamsii YIM PH30019: a promising biocontrol agent with hyperosmolar, mycoparasitism, and antagonistic activities of induced volatile organic compounds on root-rot pathogenic fungi of Panax notoginseng.

    Science.gov (United States)

    Chen, Jin-Lian; Sun, Shi-Zhong; Miao, Cui-Ping; Wu, Kai; Chen, You-Wei; Xu, Li-Hua; Guan, Hui-Lin; Zhao, Li-Xing

    2016-10-01

    Biocontrol agents are regarded as promising and environmental friendly approaches as agrochemicals for phytodiseases that cause serious environmental and health problems. Trichoderma species have been widely used in suppression of soil-borne pathogens. In this study, an endophytic fungus, Trichoderma gamsii YIM PH30019, from healthy Panax notoginseng root was investigated for its biocontrol potential. In vitro detached healthy roots, and pot and field experiments were used to investigate the pathogenicity and biocontrol efficacy of T. gamsii YIM PH30019 to the host plant. The antagonistic mechanisms against test phytopathogens were analyzed using dual culture, scanning electron microscopy, and volatile organic compounds (VOCs). Tolerance to chemical fertilizers was also tested in a series of concentrations. The results indicated that T. gamsii YIM PH30019 was nonpathogenic to the host, presented appreciable biocontrol efficacy, and could tolerate chemical fertilizer concentrations of up to 20%. T. gamsii YIM PH30019 displayed antagonistic activities against the pathogenic fungi of P. notoginseng via production of VOCs. On the basis of gas chromatography-mass spectrometry, VOCs were identified as dimethyl disulfide, dibenzofuran, methanethiol, ketones, etc., which are effective ingredients for antagonistic activity. T. gamsii YIM PH30019 was able to improve the seedlings' emergence and protect P. notoginseng plants from soil-borne disease in the continuous cropping field tests. The results suggest that the endophytic fungus T. gamsii YIM PH30019 may have a good potential as a biological control agent against notoginseng phytodiseases and can provide a clue to further illuminate the interactions between Trichoderma and phytopathogens.

  9. Cotton-based nonwovens

    Science.gov (United States)

    This article is an abbreviated description of a new cotton-based nonwovens research program at the Southern Regional Research Center, which is one of the four regional research centers of the Agricultural Research Service, U.S. Department of Agriculture. Since cotton is a significant cash crop inte...

  10. 大豆种质对花叶病毒病和疫霉根腐病抗病性的SSR标记辅助鉴定%SSR Identification of Soybean Cultivar with Resistance to Soybean Mosaic Virus and Phytophthpra Root Rot

    Institute of Scientific and Technical Information of China (English)

    韩英鹏; 赵雪; 李修平; 滕卫丽; 李文滨

    2014-01-01

    通过与花叶病毒病(soybean mosaic virus,SMV)抗性相关的SSR标记Satt114对30份大豆种质进行分子辅助鉴定,共发现10个抗SMV的种质,经摩擦接种法表型验证其中9个种质表现为抗病,即分子辅助鉴定的准确性为90%.另外,利用与疫霉根腐病(phytophthora root rot,PRR)相关的SSR标记Satt325、Satt343、Satt428、Satt005、Satt600、Satt611、Satt689、Satt579、Satt252、Satt274对相同的30份大豆种质进行分子辅助鉴定,共在2,3,5,6,12,2份大豆种质上分别检测到0,1,2,3,4,5个抗PRR的QTL,并利用菌土法盆栽验证种质的抗病性,结果表明拥有0~1个抗PRR的QTL大豆种质的病害损失率平均为94%,拥有2~3个抗PRR的QTL大豆种质的病害损失率平均为77.82%,拥有4~5个抗PRR的QTL大豆种质的病害损失率平均为36.70%.通过本研究筛选获得了1份既高抗SMV又高抗PRR的种质合05-31.

  11. Screening,identification and antibacterial activity of antagonistic bacteria FC12-05 against phytophthora root rot of tomato%番茄疫霉根腐病拮抗细菌FC12-05的筛选、鉴定及其抑菌活性初探

    Institute of Scientific and Technical Information of China (English)

    冯志珍; 李金岭; 陈太春; 马志远; 段军娜; 安德荣

    2012-01-01

    【Objective】 The strong effective biocontrol bacteria for phytophthora root rot of tomato were selected from greenhouse tomato farming soil for several years.【Method】 Random samples were conducted from greenhouse tomato farming soil for many years,separated the bacteria used plant dilute,selected directionally with several fungal pathogens such as P.capsici Leonian,Botrytis cirerea,Phytophthora nicotianae,Bipolaris sorokiniana,Fusarium oxysporum f.sp.vasinfectum,Pyricularia oryzae as the indicator bacteria;We identified the antagonistic bacteria based on morphological,physiological and biochemical characteristics,and 16S rDNA phylogenetic analysis;determined the effect of the mycelial configurationthe of pathogenic fungi,the mycelium growth of pathogenic fungi,the spore germination on pathogenic fungi spores broth germination and the control efficacy of bonsai experiment in greenhouse with the sterile fermentation of antagonistic bacteria.Then we deposited the sterile fermentation of antagonistic bacteria with ammonium sulfatem,which saturation concentration respectively was 10%,20%,25%,30%,35%,40%,50%,60%,70%,80%,90% and 100%,and tested the antifungal activity of ammonium sulfate precipitation of the antagonists.【Result】 253 strains bacterium were isolated from 30 soil samples,FC12-05,a strong effect of bacterial on Phytophthora capsici Leonian,Botrytis cirerea,Phytophthora nicotianae,Bipolaris sorokiniana,Fusarium oxysporum f.sp.vasinfectum,Pyricularia oryzae;The strain FC12-05 was identified as Bacillus siamensis.The fermented liquid of strain FC12-05 had great inhibition effect on mycelium growth of P.capsici Leonian and Botrytis cinerea,the inhibition rate of mycelium growth was 95.02% and 92.43%;the EC50 values was 10.14 and 10.78 mL/L;the inhibition rate of spore germination was 94.60% and 92.43%;the EC50 values was 2.09 and 2.53 mL/L;the control effect of FC12-05 strain on phytophthora root rot of tomato was up to 93.50%;The antifungal metabolite

  12. 7 CFR 29.6039 - Stem rot.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Stem rot. 29.6039 Section 29.6039 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem...

  13. Cotton Demand Dropping in China

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The ICAC claimed, global cotton market outlook is bleak in the 2012/2013 annual. Global cotton production is estimated at 25.9 million tons and cotton usage is estimated at 23.4 million tons. Cotton supply will exceed demand; the excess volume will reach 2.4 million tons.

  14. Dictionary of cotton: Picking & ginning

    Science.gov (United States)

    Cotton is an essential commodity for textiles and has long been an important item of trade in the world’s economy. Cotton is currently grown in over 100 countries by an estimated 100 producers. The basic unit of the cotton trade is the cotton bale which consists of approximately 500 pounds of raw c...

  15. Farmers’ State of Mind and the Policy Thinking for the Cotton Production in Shandong Province

    Institute of Scientific and Technical Information of China (English)

    Ruobing; HAN; Lin; ZHOU; Jilian; HU

    2013-01-01

    Affected by the meteorological disasters and market fluctuations,the growing area,yield and quality of cotton in Shandong Province have been reduced to varying degrees in recent years.The majority of farmers are regarded as the main body of agricultural production,whose enthusiasm for growing cotton and confidence in the cotton market play a significant role in stabilizing the growing area and improving the quality of cotton.We randomly select the cotton farmers for in-depth interview,to understand the situation of cotton cultivation and their state of mind for growing,aimed at deriving the factors influencing farmers’willingness to grow cotton.In the future,it is necessary to make the best use of the advantages and bypass the disadvantages,and in a timely manner curb the decline of cotton cultivation in the process of guiding and encouraging the cotton cultivation,in order to solve the problems of low farmers’willingness to grow cotton and sluggish cotton industry from the root.

  16. Cotton School Tells Us More--The Fourth COTTON USA Cotton School Convened in Qingdao

    Institute of Scientific and Technical Information of China (English)

    By Wang Ting

    2012-01-01

    Since the year of 2006, Cotton Council International has already convened the Cotton School for three times in China. This year, in 2012, CCI held the Cotton School in the city of Qingdao for the fourth time, generously shared with international buyers, especially the Chinese domestic purchases, the knowledge of qualified U.S. cotton.

  17. Antagonistic potential of fluorescent pseudomonads and control of charcoal rot of chickpea caused by Macrophomina phaseolina.

    Science.gov (United States)

    Kumar, Vinod; Kumar, Anuj; Kharwar, R N

    2007-01-01

    The effectiveness of plant growth promoting rhizobacteria especially Pseudomonas fluorescens isolates were tested against charcoal rot of chickpea both in green house as well as in field conditions. Most of the isolates reduced charcoal rot disease and promoted plant growth in green house. A marked increase in shoot and root length was observed in P. fluorescens treated plants. Among all the P. fluorescens isolates Pf4-99, was found most effective in the improvement of chickpea crop in green house as well as in field. Pf4-99 effectively promoted plant growth and produced indole acetic acid in culture medium. This isolate also inhibited the mycelial growth of the M. phaseolina under in vitro conditions and reduced the disease severity Potential isolate (Pf4-99) also significantly increased the biomass of the chickpea plants, shoot length, root length and protein content of the chickpea seeds. A part from these, the total number of seeds per plant and their weight were also enhanced. The colonization of Pf4-99 reduced the incidence of seed mycoflora by which indirectly enhanced the seed germination and vigour index of seedlings. The observations revealed that isolate Pf4-99 is quite effective to reduce the charcoal rot disease both in field and greenhouse, and also increases seed yields significantly Therefore, this isolate appears to be an efficient biocontrol agent against charcoal rot disease as well as yield increasing rhizobacterium.

  18. Cotton and its interaction with cotton morphology

    Science.gov (United States)

    The morphological plasticity of the cotton plant enables it to be produced in a wide variety of agro-ecological regions (Oosterhuis and Jernstedt 1999). This plasticity essentially translates to the lengthening, shortening, or interruption of its effective flowering period in response to season leng...

  19. CottonDB Enhancement

    Institute of Scientific and Technical Information of China (English)

    YU Jing; KOHEL Russell; HINZE Lori; FRELICHOWSKI James; XU Zhan-you; YU John Z; PERCY Richard

    2008-01-01

    @@ CottonDB (www.cottondb,org) was initiated in 1995.It is a database that contains genomic,genetic,and taxonomic information for cotton (Gossypium spp.).It serves both as an archival database and as a dynamic database,which incorporates new data and user resources.CottonDB is maintained at the Southern Plains Agricultural Research Center in College Station,TX.The project includes a website and database creating a repository of information for over 450,000 gene,EST,and conting sequences; genetic and physical map data; nearly 10,000 DNA primers; and 9,000 germplasm accessions.

  20. SCFP, a novel fiber-specific promoter in cotton

    Institute of Scientific and Technical Information of China (English)

    HOU Lei; LIU Hao; LI JiaBao; YANG Xia; XIAO YueHua; LUO Ming; SONG ShuiQing; YANG GuangWei; PEI Yan

    2008-01-01

    To investigate the expression pattern of GhSCFP which was isolated from cotton fiber cDNA library, a 1006 bp upstream fragment of the gene was cloned by chromosome walking and fused to GUSand GFP respectively. Histochemical GUS and GFP fluorescence analysis revealed that the expression of the report genes driven by the promoter sequence was detectable only in outer layer cells during the seed development in the transgentic tobaccos. In transgenic cotton, strong GUS activity was observed in spherical protrusions on 0 dps (days post anthesis) ovule surface, and in the 2-36 dpa fiber cells, while no GUS signals were detected in the root, leaves, stem, corolla, anther and stigma. Our data demon-strated that GhSCFP upstream sequence is a cotton fiber-specific promoter and this promoter will be useful in the molecular research on fiber cell development and in cotton fiber improvements by genetic modification.

  1. Water relations in untreated and modified wood under brown-rot and white-rot decay

    DEFF Research Database (Denmark)

    Thybring, Emil Engelund

    2017-01-01

    One key requisite for fungal decay of wood is water within cell walls. While several reviews have focused on the mechanistic relationship between water and decay of wood, this study is the first review of water relations of decayed wood material. Based on a vast compilation of experimental data...... from several literature sources, the water relations of untreated and modified wood decayed by brown-rot and white-rot fungi are examined. The aim is to investigate to what extent observations and assumptions regarding brown-rot and white-rot decay can explain changes in water relations observed during...... and after decay. Although the available experimental data for modified wood is scarce, it indicates that brown-rot and white-rot decay of non-resistant modified wood occurs by similar degradation mechanisms with similar effects on water relations as for untreated wood. From simplistic, mathematical...

  2. IMPROVING PHOSPHORUS NUTRITION OF COTTON

    Directory of Open Access Journals (Sweden)

    Walter B. Gordon

    2014-01-01

    Full Text Available Crop recovery of applied Phosphorus (P fertilizer can be low, especially during season of low soil temperature, which decreases plant root growth and nutrient uptake. The H2PO4- or HPO4-2 anions readily react with soil cations such as Calcium (Ca, Magnesium (Mg, iron (Fe and Aluminum (Al to produce various phosphate compounds of very limited water solubility. Specialty Fertilizer Products (SFP, Leawood, KS, USA has developed and patented a product registered as AVAIL® that is reported to attract and sequester antagonistic cations out of the soil solution leaving more of applied P in available form for plant uptake. To evaluate effectiveness of AVAIL product for cotton production, experiments were conducted in two locations in West Tennessee, Grand Junction (GJ in Hardeman County and Ames Plantation (AP located in Fayette County. Treatments consisted of applying Mono-Ammonium Phosphate (MAP, 11-52-0 alone or coated with AVAIL at rates of 34 or 68 kg ha-1 P2O5. A no P check was also included. An additional treatment consisting of AVAIL treated P in combination with Nutrisphere-N®, a Nitrogen (N stabilizer product offered by SFP, was also included. At GJ site, when averaged over P rates and years, AVAIL treated MAP improved tissue P concentration and increased cotton lint yield by 157 kg ha-1 over untreated MAP. At AP site, when averaged over years and P rates, application of AVAIL treated MAP increased cotton lint yield by 85 kg ha-1 over untreated MAP. In both experiments, 34 kg ha-1 AVAIL treated MAP produced higher tissue P concentrations and greater yields than 68 kg ha-1 without AVAIL. Influencing reactions in the micro-environment around the fertilizer granule has proven to have a significant benefit on the yield and P uptake of cotton. More research is needed to determine P content in the soil and further

  3. STRUCTURAL INVESTIGATIONS OF VARIOUS COTTON FIBERS AND COTTON CELLULOSES

    Directory of Open Access Journals (Sweden)

    Michael Ioelovich

    2008-02-01

    Full Text Available Macro- and crystalline structure, as well as chemical composition of fibers related to various types and sorts of Israeli cottons, both white and naturally colored, were investigated. The differences in structural parameters and chemical compositions of the cotton fibers were evaluated. Samples of cotton of the “Pima”-type had long, thin and strong fibers with highly ordered supermolecular structure. Fibers of middle-long and hybrid cottons had some lower-ordered structural organization in comparison to long-length cotton, while fibers of naturally colored cotton were characterized with disordered supermolecular and crystalline structure. Dependence of tensile strength on orientation of nano-fibrils towards the fiber axis was found. Conditions of cellulose isolation from the different cotton fibers were studied. Structural characteristics of isolated cotton celluloses and obtained MCC are discussed.

  4. Assessment of Production of Extracellular Enzymes by Trichoderma spp. For Control of Soybean Root Rot Pathogens (Fusarium oxysporum,Rhizoctonia solani)%木霉菌(胞外水解酶)拮抗大豆根腐病病原菌的机制研究

    Institute of Scientific and Technical Information of China (English)

    邵红涛; 许艳丽

    2006-01-01

    The role of extracellular enzymes by Trichoderma MM35 for control of soybean root rot pathogens(Fusarium oxysporum , Rhizoctonia solani) was assessed in vitro and in vivo. Detective levels of hydrolytic extracellular enzymes were recorded by Trichoderma MM35 using dried F. oxysporum mycelium as C-source in vitro or fresh F. oxysporum mycelium or fresh R.solani mycelium in vivo was found that there were significant increases in chitinase activities by Trichoderma MM35 in soil with inoculation of F. oxysporum. Soil infested with Trichoderma MM35 had significantly elevated chitinase and β-1,3-glueanase activities in presence of R. solani as compared to R. solani control.%通过室内试验与温室试验研究了具有生防能力的木霉菌株Trichoderma MM35所分泌的胞外水解酶在拮抗大豆根腐病病原菌(F.oxysporum、R.solani)中的作用.试验结果表明:以病原菌F.oxysporum烘干的菌丝体作唯一碳源,可以诱导Trichoderma MM35分泌几丁质酶、β-1,3-葡聚糖酶.β-1,3-葡聚糖酶高水平诱导表达在前,几丁质酶诱导表达在后.土壤中接种Trichoderma MM35、F.oxysporum和R.solani之后都能够检测到几丁质酶、β1,3-葡聚糖酶活性.向有病原菌F.oxysporum的土壤中接种Trichoderma MM35,土壤中几丁质酶活性能够显著升高.向有病原菌R.solani的土壤中接种Trichoderma MM35,土壤中的几丁质酶、β-1,3-葡聚糖酶活性都显著升高.

  5. Identification of bio-control bacterial strain KJB04-11 against soybean root rot disease and the produced lipopeptide antibiotics by the strain%大豆根腐病生防菌KJB04-11的鉴定及其产生的脂肽类抗生素

    Institute of Scientific and Technical Information of China (English)

    李旭; 马福海; 王秀娟; 孙健; 张惠文

    2012-01-01

    从大豆根围筛选到1株对尖孢镰刀菌和立枯丝核菌都具有很好拮抗作用的菌株KJB04-11,经形态观察、生理生化特征和16S rDNA序列分析,属于枯草芽孢杆菌(Bacillussubtilis).具有抗菌活性的KJB04-11发酵液无菌滤液对热和酸碱具有较强的稳定性.采用Sephadex G-25柱层析、反相HPLC和冷冻干燥从KJB04-11发酵液中分离纯化了抗菌活性成分.由红外光谱、MALDI-TOF-MS、氨基酸组成及脂肽合成酶基因扩增结果推测该菌株产生的抗菌物质为C16、C17的mycosubtilin和C15的surfactin.田间试验表明,大豆种子经KJB04-11发酵液包衣处理对大豆根腐病防效为53.6%,大豆产量提高12.5%.%A bacterial strain KJB04-11 with antagonistic effect against Fusarium oxysporum and Rhizoctonia solani was isolated from soybean rhizosphere. The strain was identified as Bacillus subtilis, based on its morphological, cultural, physiological, and biochemical characteristics, and 16S rDNA sequence analysis. The fermented filtrate with antagonistic activity showed certain thermostability and certain acidic and alkaline stability in the range of pH 1.0-13.0. The antagonistic active compositions in the fermented filtrate were purified by gel filtration on Sephadex G-25 column and RF-HPLC, and preliminarily identified as Cl6 mycosubtilin, C17 mycosubtilin, and C15 surfactin by infrared spectra, MALDI-TOF mass spectrum, amino acid composition analysis, and amplification of lipopeptide synthase gene. In field trial, the control efficacy of seed coating agent prepared with KJB04-11 against soybean root rot disease was 53. 6% , and the soybean yield was increased by 12.5% .

  6. Response of cultivars of malanga (Xanthosoma sagittifolium (L.) Schott) to dry rot

    OpenAIRE

    Ernesto Espinosa Cuéllar; Lidcay Herrera Isla; Alberto Espinosa Cuéllar; Amaurys Dávila Martínez; Alexander Bernal Cabrera; Jaime Simó González

    2017-01-01

    Malanga (Xanthosoma sagittifolium (L.) Schott) is an important food crop for over 400 million people in the tropics and subtropics. In order to determine the response of different varieties of malanga Xanthosoma to dry rot, a series of experiments were conducted in the period between 2012 and 2014. The experiments were performed on loamy Soil at the National Research Institute in Tropical Crops and Roots (INIVIT). We determined the incidence and severity of damage, yields and percent of losse...

  7. Excised radicle tips as a source of genomic DNA for PCR-based genotyping and melting curve analysis in cotton

    Indian Academy of Sciences (India)

    P Srinivasa Rao; P Sateesh Kumar; Ramesh V Sonti

    2013-03-01

    Genomic DNA isolation in cotton is complicated because of the presence of secondary metabolites that are inhibitory to PCR amplification. We report here that radicle tips, but not other parts of cotton seedlings, yield high-quality DNA that is readily amenable for PCR. The radicle-tip-excised seedlings retain viability because of the formation of adventitious roots. We demonstrate the utility of this method in distinguishing homozygotes from heterozygotes in a cotton breeding population and in hybrid seed purity testing.

  8. Cotton (Gossypium hirsutum L.).

    Science.gov (United States)

    Rathore, Keerti S; Campbell, LeAnne M; Sherwood, Shanna; Nunes, Eugenia

    2015-01-01

    Cotton continues to be a crop of great economic importance in many developing and some developed countries. Cotton plants expressing the Bt gene to deter some of the major pests have been enthusiastically and widely accepted by the farmers in three of the major producing countries, i.e., China, India, and the USA. Considering the constraints related to its production and the wide variety of products derived from the cotton plant, it offers several target traits that can be improved through genetic engineering. Thus, there is a great need to accelerate the application of biotechnological tools for cotton improvement. This requires a simple, yet robust gene delivery/transformant recovery system. Recently, a protocol, involving large-scale, mechanical isolation of embryonic axes from germinating cottonseeds followed by direct transformation of the meristematic cells has been developed by an industrial laboratory. However, complexity of the mechanical device and the patent restrictions are likely to keep this method out of reach of most academic laboratories. In this chapter, we describe the method developed in our laboratory that has undergone further refinements and involves Agrobacterium-mediated transformation of cotton cells, selection of stable transgenic callus lines, and recovery of plants via somatic embryogenesis.

  9. Cotton, biotechnology, and economic development

    OpenAIRE

    Baffes, John

    2011-01-01

    During the past decade, cotton prices remained considerably below other agricultural prices (although they recovered toward the end of 2010). Yet, between 2000-04 and 2005-09 world cotton production increased 13 percent. This paper conjectures that biotechnology-induced productivity improvements increased supplies by China and India, which, in addition to keeping cotton prices low, aided t...

  10. Strategies for managing foliar and root rot diseases of alfalfa

    Science.gov (United States)

    Diseases can be a major source of yield loss and stand decline in alfalfa. Surveys were conducted to determine the distribution of pathogens for which there is limited resistance in commercial varieties and tests were done with new crop chemicals to determine their effectiveness in controlling sever...

  11. improvement of resistance to fusarium root rot through gene ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    were crossed to each of the two susceptible cultivars to form five-parent and single crosses, respectively. Developed ... most effective control measure for FRR in common bean is through the ..... levels and/or stability of resistance beyond what.

  12. RHIZOBACTERIA AS BIOCONTROL AGENTS OF ROOT ROT DISEASE ON SHALLOT

    Directory of Open Access Journals (Sweden)

    Nunik Iriyanti Ramadhan

    2015-01-01

    Full Text Available Shallot is a high-economic value commodity, but so far the supply is still lower than the demand. One of the production problem is “moler” disease of shallot (MDS caused by Fusarium oxysporum f.sp. cepae (FOCe. The aim of this research was to study the potentiality of shallot rhizobacteria (SRB from various soil ordo to inhibit (MDS. This research was held in the Laboratory of Biology and Soil Health and Greenhouse at UNS. This research was carried out by exploring rhizobacteria of shallot planted on Entisols, Andisols, and Vertisols. Rhizobacteria exploration results were tested for their ability to control Fusarium oxysporum f.sp.cepae (FOCe. Inhibitory ability test of SRB to FOCe was carried out in vitro and on shallot in the greenhouse. The green house research used a Completely Randomized Design (CDR with two factors. The first factor was rhizobacteria combination and the second factor was various soil ordo (Andisols, Entisols, and Vertisols. Each treatment was replicated three times. It was obtained three rhizobacteria isolates from Vertisols (B15: 70%, Andisols (B12:45,55%, and Entisols (B10:46,67% being the highest inhibition results to FOCe. The combination of rhizobacteria B12 and B10 provided the lowest intensity.

  13. Submission to NCBI Sequence Read Archive (SRA): Raw read files from manuscript “RNA-seq transcriptome profiling of upland cotton (Gossypium hirsutum) root tissue under water deficit stress” NCBI SRA Accession No. PRJNA210770

    Science.gov (United States)

    Gossypium hirsutum L. cultivar Siokra L-23 was grown under rainfed and irrigated treatments in a field with very sandy soil. Root samples were collected for each treatment during the reproductive growth period. The RNA of all root tissues was used in an RNA-seq transcriptome profiling study with an ...

  14. Bacterial blight of cotton

    Directory of Open Access Journals (Sweden)

    Aïda JALLOUL

    2015-04-01

    Full Text Available Bacterial blight of cotton (Gossypium ssp., caused by Xanthomonas citri pathovar malvacearum, is a severe disease occurring in all cotton-growing areas. The interactions between host plants and the bacteria are based on the gene-for-gene concept, representing a complex resistance gene/avr gene system. In light of the recent data, this review focuses on the understanding of these interactions with emphasis on (1 the genetic basis for plant resistance and bacterial virulence, (2 physiological mechanisms involved in the hypersensitive response to the pathogen, including hormonal signaling, the oxylipin pathway, synthesis of antimicrobial molecules and alteration of host cell structures, and (3 control of the disease.

  15. RESPONSE OF CABBAGE CULTIVARS TO BLACK ROT INFECTION

    African Journals Online (AJOL)

    Yield stability of white cabbage (Brassica oleracea var. capitata) cultivars were ... and stable cultivar(s) with adequate resistance to black rot caused by ..... Principles and Procedures of Statistics: ... black rot development in introduced cabbage.

  16. New source of bacterial soft rot resistance in potato tubers

    Science.gov (United States)

    Bacterial soft rot caused by Pectobacterium and Dickeya species can cause major losses to the potato (Solanum tuberosum L.) industry, mostly due to tuber rot in storage. There are few germplasm resources for soft rot resistance breeding. Here, we introduce a resistant diploid wild potato relative, M...

  17. The effects of Fe2O3 nanoparticles on physiology and insecticide activity in non-transgenic and Bt-transgenic cotton

    Directory of Open Access Journals (Sweden)

    Nhan eLe Van

    2016-01-01

    Full Text Available As the demands for nanotechnology and nanoparticle (NP applications in agriculture increase, the ecological risk has drawn more attention because of the unpredictable results of interactions between NPs and transgenic crops. In this study, we investigated the effects of various concentrations of Fe2O3 NPs on Bt-transgenic cotton in comparison with conventional cotton for 10 days. Each treatment was conducted in triplicate, and each experiment was repeated three times. Results demonstrated that Fe2O3 nanoparticles (NPs inhibited the plant height and root length of Bt-transgenic cotton and promoted root hairs and biomass of non-transgenic cotton. Nutrients such as Na and K in Bt-transgenic cotton roots increased, while Zn contents decreased with Fe2O3 NPs. Most hormones in the roots of Bt-transgenic cotton increased at low Fe2O3 NP exposure (100 mg·L−1 but decreased at high concentrations of Fe2O3 NPs (1000 mg·L−1. Fe2O3 NPs increased the Bt-toxin in leaves and roots of Bt-transgenic cotton. Fe2O3 NPs were absorbed into roots, then transported to the shoots of both Bt-transgenic and non-transgenic cottons. The bioaccumulation of Fe2O3 NPs in plants might be a potential risk for agricultural crops and affect the environment and human health.

  18. Cotton Life Cycle Inventory & Life Cycle Assessment--A Landmark Benchmark for Cotton Sustainability

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Recently, Cotton Incorporated announced the completion of a comprehensive life cycle inventory and life cycJe analysis of cotton products. The endeavor is part of the Cotton Foundation VlSIQN 21 Project and included the participation of the National Cotton Council, Cotton Council International and Cotton Incorporated. The two-year study, managed by PE International,

  19. New Cotton Trade Terms Flashed in China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    On May 8th, 2006, China Cotton Import Regulations-Cotton Purchase Contract and General Terms (Applicable to Non-Chinese Cotton Trade), short for China Cotton Association Terms (CCAT) was issued and put into practice, which was welcomed by both China and the countries who trade cotton with China.

  20. Cotton Trip in China

    Institute of Scientific and Technical Information of China (English)

    Wang Ting

    2010-01-01

    @@ During their trip in Beijing,the leadership delegation members,Charles Parker,Harrison Ashley(Vice President of NCC Ginner Services),along with Karin Malmstrom(China Director of CCI)shared a time to accept the interview,giving a general introduction about their China trip and the cotton industry in USA.

  1. QTL mapping of fruit rot resistance to the plant pathogen Phytophthora capsici in a recombinant inbred line Capsicum annuum population.

    Science.gov (United States)

    Naegele, R P; Ashrafi, H; Hill, T A; Chin-Wo, S Reyes; Van Deynze, A E; Hausbeck, M K

    2014-05-01

    Phytophthora capsici is an important pepper (Capsicum annuum) pathogen causing fruit and root rot, and foliar blight in field and greenhouse production. Previously, an F6 recombinant inbred line population was evaluated for fruit rot susceptibility. Continuous variation among lines and partial and isolate-specific resistance were found. In this study, Phytophthora fruit rot resistance was mapped in the same F6 population between Criollo del Morelos 334 (CM334), a landrace from Mexico, and 'Early Jalapeno' using a high-density genetic map. Isolate-specific resistance was mapped independently in 63 of the lines evaluated and the two parents. Heritability of the resistance for each isolate at 3 and 5 days postinoculation (dpi) was high (h(2) = 0.63 to 0.68 and 0.74 to 0.83, respectively). Significant additive and epistatic quantitative trait loci (QTL) were identified for resistance to isolates OP97 and 13709 (3 and 5 dpi) and 12889 (3 dpi only). Mapping of fruit traits showed potential linkage with few disease resistance QTL. The partial fruit rot resistance from CM334 suggests that this may not be an ideal source for fruit rot resistance in pepper.

  2. INFLUÊNCIA DA DENSIDADE DE INÓCULO DE Fusarium solani f.sp. phaseoli NA SEVERIDADE DA PODRIDÃO RADICULAR SECA DO FEIJOEIRO EFFECT OF Fusarium solani f.sp. phaseoli INOCULUM DENSITY ON DRY ROOT ROT SEVERITY IN THE COMMON BEAN

    Directory of Open Access Journals (Sweden)

    Gesimária Ribeiro Costa

    2007-09-01

    Full Text Available

    Foram testadas quatro densidades de inóculo de Fusarium solani, em gramas por litro de solo (1,0; 2,0; 4,0 e 8,0 e um tratamento testemunha, em solo tipo Latossolo Vermelho-Escuro, cultivado e não cultivado, com o objetivo de determinar a densidade mínima de inóculo no solo necessária para a ocorrência de podridão radicular seca do feijoeiro. Como variáveis respostas foram avaliadas: número de microorganismos totais do solo, número de propágulos de F. solani, atividade microbiológica total do solo e severidade da doença em plântulas. Os resultados indicaram que a densidade de inóculo do fungo variou com o tipo de solo. Para um solo não cultivado a densidade necessária para causar a doença esteve acima de 5.127 propágulos por grama de solo, enquanto para o solo cultivado a densidade de inóculo para causar doença foi de 3.701 propágulos por grama de solo. Os índices de doença em plântulas cultivadas sob o solo cultivado foram duas vezes superiores ao índice de doença de plântulas sob o solo não cultivado. A atividade microbiológica total nos solos, determinada pela desidrogenase de fluorescina diacetato, não se correlacionou com a população dos microorganismos, indicando que a simples presença desses não implica em que estejam ativos.

    PALAVRAS-CHAVE: Solo supressivo; solo conducivo; Phaseolus vulgaris.

    Four densities of Fusarium solani inoculum (1, 2, 4 and 8 g/L of soil were tested for determining the minimum inoculum density for the occurrence of bean dry root rot, in two soil types. The response variables evaluated were the total number of microorganisms in the soil, the number of F. solani f. sp. phaseoli propagules, total soil microbial activity and seedling disease severity

  3. Isolamento e seleção de fungos causadores da podridão-branca da madeira em florestas de Eucalyptus spp. com potencial de degradação de cepas e raízes Isolation and screening of wood white rot fungi from Eucalyptus spp. forests with potential for use in degradation of stumps and roots

    Directory of Open Access Journals (Sweden)

    Sandra Kunieda de Alonso

    2007-02-01

    Full Text Available Este trabalho objetivou isolar fungos causadores da podridão-branca da madeira, a partir de basidiocarpos e de fragmentos de madeira de eucalipto coletados em várias regiões do país, bem como testar seu potencial de degradação de cepas e raízes mortas em plantios comerciais de eucalipto, após o corte raso. Para o isolamento dos fungos foi desenvolvido um meio de cultura de serragem de eucalipto-ágar. Dentre 292 isolados obtidos e submetidos ao teste de Bavendamm, 144 foram classificados como causadores de podridão-branca, capazes de produzir fenoloxidases. Dentre as nove relações C/N testadas, observou-se uma tendência de ocorrer maior degradação de cavacos naquelas iguais a 60 : 1, 200 : 1 e 300 : 1. Utilizando a relação C/N igual a 60 : 1, realizaram-se dois experimentos para avaliar a degradação de cavacos de Eucalyptus saligna por isolados fúngicos de podridão-branca. No primeiro experimento, avaliado aos 90 dias de incubação, foram selecionados sete isolados, que causaram perda de peso em cavacos superior ou igual à causada por Trametes versicolor, usado para comparação. No segundo experimento foram testados 46 isolados fúngicos. Dentre os mais eficientes estavam os sete isolados selecionados no primeiro teste, além de outros quatro isolados. Baseado na análise de DNA, seis isolados foram identificados, sendo três pertencentes à espécie Pycnoporus sanguineus, um ao gênero Peniophora sp., um ao gênero Pestalotiopsis sp. e um ao gênero Ganoderma sp.The aim of this work was to isolate native wood white-rot fungi from fungal fruit-bodies and eucalyptus wood fragments from different regions of Brazil and to test their potential for degrading dead stumps and roots in Eucalyptus plantings after harvest. Fungi isolates were obtained in a culture medium composed by Eucalyptus sawdust and agar. Among 292 isolates submitted to the Banvedamm test, 144 were classified as phenoloxidases producing isolates. Among nine C

  4. Cotton Incorporated Documents Industry Gains at ICAC

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Those who attack the cotton industry for its perceived impact on the environment will need to have their facts straight, thanks to a major research project undertaken by Cotton Incorporated: a life-cycle assessment (LCA) for cotton.

  5. Cotton in Benin: governance and pest management

    NARCIS (Netherlands)

    Togbe, C.E.

    2013-01-01

    Key words: cotton, synthetic pesticides, neem oil (Azadirachta indica), Beauveria bassiana, Bacillus thuringiensis, field experiment, farmers’ participation   Pests are one of the main factors limiting cotton production worldwide. Most of the pest control strategies in cotton producti

  6. A novel knotted cotton-thread carrier:Its potential use in achieving the biomass renewal of Phanerochaete chrysosporium in an immobilized growth system

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In order to achieve an innovative strategy to renew the biomass of Phanerochaete chrysosporium in an immobilized growth system which can maintain white-rot fungi biomass, a novel knotted cotton-thread carrier was designed and made. By using a high-speed stirring apparatus under the conditions of 1400 r/min stirring speed for 6 min, mycelia immobilized on the knotted cotton-thread carriers were exfoliated completely and homogenized to a proper size. Furthermore, the homogenized mycelia from the immobilized mycelia can resume their growth on the knotted cotton-thread carriers in agitated flask cultures. The average regrowth biomass on the new carriers and the reused carriers was 0.0171 g/carrier and 0.0314 g/carrier, respectively. It proves that the knotted cotton-thread carrier performs perfectly in homogening the immobilized mycelia to achieve the biomass renewal of P. chrysosporium in an immobilized growth system.

  7. Distribution of Root and Cotton Yield and Temporal-Spatial Variation in Soil Nutrients in Jujube-Cotton Intercropping Ecosystem%枣棉间作生态系统内根系和棉花产量分布及土壤养分时空变化

    Institute of Scientific and Technical Information of China (English)

    宋锋惠; 吴正保; 史彦江

    2012-01-01

    为提高枣棉间作系统内肥料管理水平,在棉花不同物候期,测定系统内土壤养分的空间差异性.结果表明:土壤有机质质量分数随棉花生育进程基本呈增加的趋势,且枣树西侧的土壤有机质质量分数高于东侧,并且0<H(土层深度)≤20 cm土层有机质质量分数明显高于20 cm<H≤40 cm土层;土壤中速效N、P和K的质量分数表现出明显的时空分布差异性.随着棉花生育进程,土壤中速效N、P、K的质量分数均呈下降趋势.在水平分布上,随距枣树距离的增加,土壤中速效N、P质量分数均表现出先下降再上升的变化规律,距离树体130 cm左右的土壤速效N、P质量分数最低,而速效K质量分数则相对较为平稳.在垂直分布上,随着土层深度的增加,土壤速效P质量分数呈明显降低现象,而速效N、K质量分数变化较小.%The spatial variation in soil nutrients was studied in different phenological stages of cotton in order to improve fertilizer management in Jujube-cotton Intercropping Ecosystem ( JIE). Result showed that the content of soil organic matter increased with the growing process of cotton. Moreover, the organic matter content in the soil to the west of the jujube trees was higher than that to the east, and the organic matter content in 0-20 cm soil layer was higher than that in 20-40 cm soil layer. Temporal and spatial heterogeneity of contents of available N, P, and K in soil was observed in JIE. Contents of available N, P, and K decreased with the growing process of cotton. In horizontal distribution, the contents of soil available N, P, and K first decreased and then increased with increasing distance from the jujube trees, and the contents of available N and P in the soil located at 130 cm away from the jujube trees were lowest, while the available K content was relatively stable. In vertical distribution, soil available P content decreased with increasing soil depth, while the contents of

  8. Rhizosphere competent Mesorhizobiumloti MP6 induces root hair curling, inhibits Sclerotinia sclerotiorum and enhances growth of Indian mustard (Brassica campestris)

    National Research Council Canada - National Science Library

    Shikha Chandra; Kamlesh Choure; Ramesh C. Dubey; Dinesh K. Maheshwari

    2007-01-01

    .... loti MP6 in rhizosphere due to root exudates of B. campestris. In dual culture technique the strain showed a strong antagonistic effect against Sclerotinia sclerotiorum, a white rot pathogen of Brassica campestris. The growth of S...

  9. Plant growth regulation of Bt-cotton through Bacillus species.

    Science.gov (United States)

    Pindi, Pavan Kumar; Sultana, Tasleem; Vootla, Praveen Kumar

    2014-06-01

    Deccan plateau in India periodically experiences droughts due to irregular rain fall and the soil in many parts of the region is considered to be poor for farming. Plant growth promoting rhizobacteria are originally defined as root-colonizing bacteria, i.e., Bacillus that cause either plant growth promotion or biological control of plant diseases. The study aims at the isolation of novel Bacillus species and to assess the biotechnological potential of the novel species as a biofertilizer, with respect to their plant growth promoting properties as efficient phosphate-solubilizing bacteria. Seven different strains of Bacillus were isolated from cotton rhizosphere soil near boys' hostel of Palamuru University which belongs to Deccan plateau. Among seven isolated strains, Bacillus strain-7 has shown maximum support for good growth of eight cotton cultivars. This bacterial species is named Bacillus sp. PU-7 based on the phenotypic and phylogenetic analysis. Among eight cotton cultivars, Mahyco has shown high levels of IAA, proteins, chlorophyll, sugars and low level of proline. Efficacy of novel Bacillus sp. PU-7 with Mahyco cultivar has been checked experimentally at field level in four different cotton grown agricultural soils. The strains supported plant growth in almost all the cases, especially in the deep black soil, with a clear evidence of maximum plant growth by increased levels of phytohormone production and biochemical analysis, followed by shallow black soil. Hence, it is inferred that the novel isolate can be used as bioinoculant in the cotton fields.

  10. Myxomycetes of the rotting cherry wood

    Directory of Open Access Journals (Sweden)

    Wanda Stojanowska

    2014-08-01

    Full Text Available During the years 1974-1975 on rotting cherry wood development of some Myxomycetes was observed. In that time 6 species of slime molds were noted: Arcyria denudata, Comatricha typhoides, Dyctidium cancellatum, Lycogala epidendrum, Physarum cinereum, Stemonitis ferruginea. In the decomposition of organic compounds apart from Myxomycetes other organism (Coprinus dessiminafus also take part.

  11. Postharvest Rhizopus rot on sugar beet

    Science.gov (United States)

    Rhizopus species have been reported as a minor post-harvest rot on sugar beet, particularly under temperatures above 5 deg C. In 2010, Rhizopus was isolated from beets collected from Michigan storage piles in February at a low frequency. However, recent evidence from Michigan has found a high incide...

  12. Cotton 2K-Management tools for irrigated cotton

    Science.gov (United States)

    The use of simulation models to manage crops was a concept introduced in the 1980’s. For example, the cotton simulation model known as GOSSYM was made available in 1989 and was used by both producers and consultants to manage cotton in real time. More recently, Dr. Avi Marani, Professor Emeritus, Sc...

  13. Removal of methylene blue from aqueous solution using cotton stalk, cotton waste and cotton dust

    Energy Technology Data Exchange (ETDEWEB)

    Ertas, Murat [Department of Forest Industrial Engineering, Faculty of Forestry, Kahramanmaras Sutcu Imam University, 46060 Kahramanmaras (Turkey); Acemioglu, Bilal, E-mail: acemioglu@kilis.edu.tr [Department of Chemistry, Faculty of Science and Arts, Kilis 7 Aralik University, 79000 Kilis (Turkey); Alma, M. Hakki [Department of Forest Industrial Engineering, Faculty of Forestry, Kahramanmaras Sutcu Imam University, 46060 Kahramanmaras (Turkey); Usta, Mustafa [Department of Forest Industrial Engineering, Faculty of Forestry, Karadeniz Technical University, 61080 Trabzon (Turkey)

    2010-11-15

    In this study, cotton stalk (CS), cotton waste (CW) and cotton dust (CD) was used as sorbents to remove methylene blue (MB) from aqueous solution by batch sorption technique. Effects of initial dye concentration, solution pH, solution temperature and sorbent dose on sorption were studied. It was seen that the removal of methylene blue increased with increasing initial dye concentration (from 25 to 100 mg/l), solution pH (from 5 to 10), solution temperature (from 20 to 50 deg. C) and sorbent dose (from 0.25 to 1.50 g/50 ml). The maximum dye removal was reached at 90 min. Sorption isotherms were analyzed by Langmuir and Freundlich models at different temperatures of 20, 30, 40 and 50 deg. C, and the results were discussed in detail. Moreover, the thermodynamics of sorption were also studied. It was found that the values of standard free energy ({Delta}G{sup o}) were positive for cotton stalk and negative for cotton waste and cotton dust. The values of standard enthalpy ({Delta}H{sup o}) and entropy ({Delta}S{sup o}) were found to be positive, and the obtained results were interpreted in detail. The results of this study showed that cotton stalk, cotton waste and cotton dust could be employed as effective and low-cost materials for the removal of dyes from aqueous solution.

  14. Linking fungal communities in roots, rhizosphere, and soil to the health status of Pisum sativum

    DEFF Research Database (Denmark)

    Xu, Lihui; Ravnskov, Sabine; Larsen, John

    2012-01-01

    the three fields identified a number of OTUs that were more abundant in healthy roots. Pathogens such as Fusarium oxysporum were abundant in diseased roots in some fields. Patterns of disease and causal agents of root rot were different among the three fields, which were also reflected in fungal communities...

  15. Exploring biomedical applications of cotton

    Science.gov (United States)

    The use of cotton as a biomaterial for design of improved wound dressings, and other non-implantable medical textiles will be considered. The research and development of cotton-based wound dressings, which possess a mechanism-based mode of action, has entered a new level of understanding in recent ...

  16. Exploring biomedical ppplications of cotton

    Science.gov (United States)

    The use of cotton as a biomaterial for design of improved wound dressings, and other non-implantable medical textiles will be considered. The research and development of cotton-based wound dressings, which possess a mechanism-based mode of action, has entered a new level of understanding in recent y...

  17. The Spindle Type Cotton Harvester

    Science.gov (United States)

    The spindle type cotton picker was commercialized during the mid 1900’s and is currently produced by two US agricultural equipment manufacturers, John Deere and CaseIH. Picking is the predominate machine harvest method used throughout the US and world. Harvesting efficiency of a spindle type cotton ...

  18. Cotton Textile: Brisk against Bleak

    Institute of Scientific and Technical Information of China (English)

    Dennis K.Zhao

    2009-01-01

    @@ The 6th International cotton and cotton textile conference already scheduled on Sept.8-10 in Xinjiang,China's largest cotton growing area,was called off on a short notice of rascal needle dabbing that had caused a widespread public consternation.But the information that is focused on the leitmotif of "financial crisis and revitalization of textile industry for adjustment,upgrading and innovation"is to be shared,discussed at the upcoming resumed meeting.Cotton textile industry is and will be the most important driver for the global textile and clothing sector as it provides jobs not only for the residents living in the cities,but also for the farmers growing cotton in the poverty-ridden countryside.China and India are the most important players in this sector,for both are the most populous countries in the world...

  19. Isolation of laccase gene-specific sequences from white rot and brown rot fungi by PCR

    Energy Technology Data Exchange (ETDEWEB)

    D`Souza, T.M.; Boominathan, K.; Reddy, C.A. [Michigan State Univ., East Lansing, MI (United States)

    1996-10-01

    Degenerate primers corresponding to the consensus sequences of the copper-binding regions in the N-terminal domains of known basidiomycete laccases were used to isolate laccase gene-specific sequences from strains representing nine genera of wood rot fungi. All except three gave the expected PCR product of about 200 bp. Computer searches of the databases identified the sequences of each of the PCR product of about 200 bp. Computer searches of the databases identified the sequence of each of the PCR products analyzed as a laccase gene sequence, suggesting the specificity of the primers. PCR products of the white rot fungi Ganoderma lucidum, Phlebia brevispora, and Trametes versicolor showed 65 to 74% nucleotide sequence similarity to each other; the similarity in deduced amino acid sequences was 83 to 91%. The PCR products of Lentinula edodes and Lentinus tigrinus, on the other hand, showed relatively low nucleotide and amino acid similarities (58 to 64 and 62 to 81%, respectively); however, these similarities were still much higher than when compared with the corresponding regions in the laccases of the ascomycete fungi Aspergillus nidulans and Neurospora crassa. A few of the white rot fungi, as well as Gloeophyllum trabeum, a brown rot fungus, gave a 144-bp PCR fragment which had a nucleotide sequence similarity of 60 to 71%. Demonstration of laccase activity in G. trabeum and several other brown rot fungi was of particular interest because these organisms were not previously shown to produce laccases. 36 refs., 6 figs., 2 tabs.

  20. Soil Temperature Dependent Growth of Cotton Seedlings Before Emergence

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Soil temperature is an important variable governing plant growth and development.Studies were conducted under laboratory conditions to determine the effect of soil temperature on root and shoot growth of cotton during emergence.Cotton seedlings were grown for 192 h at 20,32 and 38℃ in soil packed in 300 mm long and 50 mm diameter cylinders.The data indicated that the longest roots(173 ram)as well as shoots(152 mm)were recorded at 32 ℃ followed by 20 (130 mm root and 82 mm shoot)and 38℃(86 mm root and 50 mm shoot).Roots grown at 20 and 38 ℃ were 20% and 50% shorter,respectively,than those grown at 32℃ after 192 h.Roots and shoots exhibited the lowest length and dry biomass at 38℃.Shoot lengths grown at 20(74 ram)and 38℃(51 mm)were 44% and 61% shorter than those grown at 32℃(131 mm)after 180 h growth period,respectively.Growth at all three temperatures followed a similar pattern.Initially there was a linear growth phase followed by the reduction or cessation of growth.Time to cessation of growth varied with temperature and decreased faster at higher temperatures.Sowing of cotton should be accomlplished before seedbed reaches a soil temperature(≥38℃)detrimental for emergence.Further,the seedbeds should be capable of providing sufficient moisture and essential nutrients for emerging seedling before its seed reserves are exhausted to enhance seedling establishment in soil.

  1. China Cotton label to be generalized

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    "China Cotton"authorization press conference was held in Beijing on October 11. China Cotton Association granted authorization to the first four enterprises, allowing them to use the label of China Cotton on their qualified products. Shandong Lanyan Group, Beijing Miantian Textile Co., Ltd are among the fi rst companies authorized to use China Cotton label.

  2. CCI President Participated in China Cotton Summit

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ On May 7-8 the 2010 China Cotton Summit and the International Cotton Fair were held in Sanya, Hainan Province, China. Mr. Wallace L. Darneille, the new president of Cotton Council International (CCI) made a special trip to China to participate in the event and present on the "cotton and textile supply and demand situation in the U.S."

  3. Integrated management of foot rot of lentil using biocontrol agents under field condition.

    Science.gov (United States)

    Hannan, M A; Hasan, M M; Hossain, I; Rahman, S M E; Ismail, Alhazmi Mohammed; Oh, Deog-Hwan

    2012-07-01

    The efficacy of cowdung, Bangladesh Institute of Nuclear Agriculture (BINA)-biofertilizer, and Bangladesh Agricultural University (BAU)-biofungicide, alone or in combination, was evaluated for controlling foot rot disease of lentil. The results exhibited that BINA-biofertilizer and BAUbiofungicide (peat soil-based Rhizobium leguminosarum and black gram bran-based Trichoderma harzianum) are compatible and have combined effects in controlling the pathogenic fungi Fusarium oxysporum and Sclerotium rolfsii, which cause the root rot of lentil. Cowdung mixing with soil (at 5 t/ha) during final land preparation and seed coating with BINA-biofertilizer and BAU-biofungicide (at 2.5% of seed weight) before sowing recorded 81.50% field emergence of lentil, which showed up to 19.85% higher field emergence over the control. Post-emergence deaths of plants due to foot rot disease were significantly reduced after combined seed treatment with BINA-biofertilizer and BAU-biofungicide. Among the treatments used, only BAU-biofungicide as the seed treating agent resulted in higher plant stand (84.82%). Use of BINA-biofertilizer and BAU-biofungicide as seed treating biocontrol agents and application of cowdung in the soil as an organic source of nutrient resulted in higher shoot and root lengths, and dry shoot and root weights of lentil. BINA-biofertilizer significantly increased the number of nodules per plant and nodules weight of lentil. Seeds treating with BAUbiofungicide and BINA-biofertilizer and soil amendment with cowdung increased the biomass production of lentil up to 75.56% over the control.

  4. Charm of Cotton Art COTTON USA: Naturally Color Your Life: Cotton & Patchwork Exhibition

    Institute of Scientific and Technical Information of China (English)

    Flora Zhao

    2012-01-01

    The grand opening of Cotton Council International's (CCI) finale event Naturally Color YourLife: Cotton & Patchwork by CO-FFON USA took place in Beijing's 798 Art Bridge Gallery on May 25th, 2012. The exhibition was a perfect marriage of the constant pursuit of traditional patchwork art with the fantastic imagination of modern design.

  5. Rot is a key regulator of Staphylococcus aureus biofilm formation

    Science.gov (United States)

    Mootz, Joe M.; Benson, Meredith A.; Heim, Cortney E.; Crosby, Heidi A.; Kavanaugh, Jeffrey S.; Dunman, Paul M.; Kielian, Tammy; Torres, Victor J.; Horswill, Alexander R.

    2015-01-01

    AUTHOR SUMMARY Staphylococcus aureus is a significant cause of chronic biofilm infections on medical implants. We investigated the biofilm regulatory cascade and discovered that the repressor of toxins (Rot) is part of this pathway. A USA300 community-associated methicillin-resistant S. aureus (CA-MRSA) strain deficient in Rot was unable to form a biofilm using multiple different assays, and we found rot mutants in other strain lineages were also biofilm deficient. By performing a global analysis of transcripts and protein production controlled by Rot, we observed that all the secreted protease genes were upregulated in a rot mutant, and we hypothesized that this regulation could be responsible for the biofilm phenotype. To investigate this question, we determined that Rot bound to the protease promoters, and we observed that activity levels of these enzymes, in particular the cysteine proteases, were increased in a rot mutant. By inactivating these proteases, biofilm capacity was restored to the mutant, demonstrating they are responsible for the biofilm negative phenotype. Finally, we tested the rot mutant in a mouse catheter model of biofilm infection and observed a significant reduction in biofilm burden. Thus S. aureus uses the transcription factor Rot to repress secreted protease levels in order to build a biofilm. PMID:25612137

  6. Anchorage of mature conifers: resistive turning moment, root-soil plate geometry and root growth orientation.

    Science.gov (United States)

    Lundström, Tor; Jonas, Tobias; Stöckli, Veronika; Ammann, Walter

    2007-09-01

    Eighty-four mature Norway spruce (Picea abies L. Karst), silver fir (Abies alba Mill) and Scots pine (Pinus sylvestris L.) trees were winched over to determine the maximum resistive turning moment (M(a)) of the root-soil system, the root-soil plate geometry, the azimuthal orientation of root growth, and the occurrence of root rot. The calculation of M(a), based on digital image tracking of stem deflection, accounted not only for the force application and its changing geometry, but also for the weight of the overhanging tree, representing up to 42% of M(a). Root rot reduced M(a) significantly and was detected in 25% of the Norway spruce and 5% of the silver fir trees. Excluding trees with root rot, differences in M(a) between species were small and insignificant. About 75% of the variance in M(a) could be explained by one of the four variables--tree mass, stem mass, stem diameter at breast height squared times tree height, and stem diameter at breast height squared. Among the seven allometric variables assessed above ground, stem diameter at breast height best described the root-soil plate dimensions, but the correlations were weak and the differences between species were insignificant. The shape of the root-soil plate was well described by a depth-dependent taper model with an elliptical cross section. Roots displayed a preferred azimuthal orientation of growth in the axis of prevailing winds, and the direction of frequent weak winds matched the orientation of growth better than that of rare strong winds. The lack of difference in anchorage parameters among species probably reflects the similar belowground growth conditions of the mature trees.

  7. Extensive sampling of basidiomycete genomes demonstrates inadequacy of the white rot/ brown rot paradigm for wood decay fungi

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Robert; Salamov, Asaf; Brown, Daren W.; Nagy, Laszlo G.; Floudas, Dimitris; Held, Benjamin; Levasseur, Anthony; Lombard, Vincent; Morin, Emmanuelle; Otillar, Robert; Lindquist, Erika; Sun, Hui; LaButti, Kurt; Schmutz, Jeremy; Jabbour, Dina; Luo, Hong; Baker, Scott E.; Pisabarro, Antonio; Walton, Jonathan D.; Blanchette, Robert; Henrissat, Bernard; Martin, Francis; Cullen, Dan; Hibbett, David; Grigoriev, Igor V.

    2014-03-14

    Basidiomycota (basidiomycetes) make up 32percent of the described fungi and include most wood decaying species, as well as pathogens and mutualistic symbionts. Wood-decaying basidiomycetes have typically been classified as either white rot or brown rot, based on the ability (in white rot only) to degrade lignin along with cellulose and hemicellulose. Prior genomic comparisons suggested that the two decay modes can be distinguished based on the presence or absence of ligninolytic class II peroxidases (PODs), as well as the abundance of enzymes acting directly on crystalline cellulose (reduced in brown rot). To assess the generality of the white rot/brown rot classification paradigm we compared the genomes of 33 basidiomycetes, including four newly sequenced wood decayers, and performed phylogenetically-informed Principal Components Analysis (PCA) of a broad range of gene families encoding plant biomass-degrading enzymes. The newly sequenced Botryobasidium botryosum and Jaapia argillacea genomes lack PODs, but possess diverse enzymes acting on crystalline cellulose, and they group close to the model white rot species Phanerochaete chrysosporium in the PCA. Furthermore, laboratory assays showed that both B. botryosum and J. argillacea can degrade all polymeric components of woody plant cell walls, a characteristic of white rot. We also found expansions in reducing polyketide synthase genes specific to the brown rot fungi. Our results suggest a continuum rather than a dichotomy between the white rot and brown rot modes of wood decay. A more nuanced categorization of rot types is needed, based on an improved understanding of the genomics and biochemistry of wood decay.

  8. Water-deficit inducible expression of a cytokinin biosynthetic gene IPT improves drought tolerance in cotton.

    Directory of Open Access Journals (Sweden)

    Sundaram Kuppu

    Full Text Available Water-deficit stress is a major environmental factor that limits agricultural productivity worldwide. Recent episodes of extreme drought have severely affected cotton production in the Southwestern USA. There is a pressing need to develop cotton varieties with improved tolerance to water-deficit stress for sustainable production in water-limited regions. One approach to engineer drought tolerance is by delaying drought-induced senescence via up-regulation of cytokinin biosynthesis. The isopentenyltransferase gene (IPT that encodes a rate limiting enzyme in cytokinin biosynthesis, under the control of a water-deficit responsive and maturation specific promoter P(SARK was introduced into cotton and the performance of the P(SARK::IPT transgenic cotton plants was analyzed in the greenhouse and growth chamber conditions. The data indicate that P(SARK::IPT-transgenic cotton plants displayed delayed senescence under water deficit conditions in the greenhouse. These plants produced more root and shoot biomass, dropped fewer flowers, maintained higher chlorophyll content, and higher photosynthetic rates under reduced irrigation conditions in comparison to wild-type and segregated non-transgenic lines. Furthermore, P(SARK::IPT-transgenic cotton plants grown in growth chamber condition also displayed greater drought tolerance. These results indicate that water-deficit induced expression of an isopentenyltransferase gene in cotton could significantly improve drought tolerance.

  9. Sampling nucleotide diversity in cotton

    Directory of Open Access Journals (Sweden)

    Yu John Z

    2009-10-01

    Full Text Available Abstract Background Cultivated cotton is an annual fiber crop derived mainly from two perennial species, Gossypium hirsutum L. or upland cotton, and G. barbadense L., extra long-staple fiber Pima or Egyptian cotton. These two cultivated species are among five allotetraploid species presumably derived monophyletically between G. arboreum and G. raimondii. Genomic-based approaches have been hindered by the limited variation within species. Yet, population-based methods are being used for genome-wide introgression of novel alleles from G. mustelinum and G. tomentosum into G. hirsutum using combinations of backcrossing, selfing, and inter-mating. Recombinant inbred line populations between genetics standards TM-1, (G. hirsutum × 3-79 (G. barbadense have been developed to allow high-density genetic mapping of traits. Results This paper describes a strategy to efficiently characterize genomic variation (SNPs and indels within and among cotton species. Over 1000 SNPs from 270 loci and 279 indels from 92 loci segregating in G. hirsutum and G. barbadense were genotyped across a standard panel of 24 lines, 16 of which are elite cotton breeding lines and 8 mapping parents of populations from six cotton species. Over 200 loci were genetically mapped in a core mapping population derived from TM-1 and 3-79 and in G. hirsutum breeding germplasm. Conclusion In this research, SNP and indel diversity is characterized for 270 single-copy polymorphic loci in cotton. A strategy for SNP discovery is defined to pre-screen loci for copy number and polymorphism. Our data indicate that the A and D genomes in both diploid and tetraploid cotton remain distinct from each such that paralogs can be distinguished. This research provides mapped DNA markers for intra-specific crosses and introgression of exotic germplasm in cotton.

  10. Linking fungal communities in roots, rhizosphere, and soil to the health status of Pisum sativum

    DEFF Research Database (Denmark)

    Xu, Lihui; Ravnskov, Sabine; Larsen, John;

    2012-01-01

    the three fields identified a number of OTUs that were more abundant in healthy roots. Pathogens such as Fusarium oxysporum were abundant in diseased roots in some fields. Patterns of disease and causal agents of root rot were different among the three fields, which were also reflected in fungal communities......Changes in fungal communities associated with healthy and diseased pea roots were investigated using deep amplicon pyrosequencing in three spatial compartments: roots, rhizosphere, and surrounding soil. Thirty root systems were collected from three fields, half of which showing clear symptoms...... of root rot. In total, 500 461 internal transcribed spacer-1 sequences were obtained that were clustered into 123 (roots), 271 (rhizosphere), and 440 (bulk soil) nonsingleton operational taxonomic units (OTUs). Species richness was highest in bulk soils and lowest in roots; however, no notable differences...

  11. Arbuscular mycorrhizal fungi and colonization stimulant in cotton and maize

    Directory of Open Access Journals (Sweden)

    Fabrício Henrique Moreira Salgado

    Full Text Available ABSTRACT: The objective of this study was to evaluate the effects of inoculation with different arbuscular mycorrhizal fungi native to Cerrado, associated with the application of colonization stimulant (7-hydroxy, 4’-methoxy-isoflavone at the initial growth of cotton and maize plants in a greenhouse. The experiment was carried out in a completely randomized design and 7x2 factorial scheme, with five species of arbuscular mycorrhizal fungi and combined inoculation (uniting all species in equal proportion and native fungi, in the presence and absence of colonization stimulant in maize and cotton crops. Shoots dry matter (SDM, roots dry matter (RDM, mycorrhizal colonization and accumulation of calcium, zinc and phosphorus in the SDM were evaluated at flowering. Inoculation of arbuscular mycorrhizal fungi and the use of colonization stimulant at low density of arbuscular mycorrhizal fungi propagules was beneficial to plant development. Inoculation with mycorrhizal fungi demonstrated different effects for the various parameters evaluated in cotton and maize, and the application of colonization stimulant promoted higher mycorrhizal colonization and initial growth in cotton, when associated with native AMF, and in corn, when associated with inoculation with Dentiscutata heterogama, Gigaspora margarita and Rhizophagus clarus.

  12. Utilization of Cotton DNA Markers in Cotton Breeding

    Institute of Scientific and Technical Information of China (English)

    CANTRELL Roy G; XIAO Jin-hua

    2008-01-01

    @@ Informative,portable,and efficient DNA markers have the potential to accelerate genetic gain in cotton breeding.Discovery and widespread application of DNA markers to cotton has traditionally lagged behind other major crop species.The reasons are well known to ICGI participants.The foundation for widespread development and application of DNA markers has been laid by ICGI and research within the private sector.

  13. Cotton bollworm resistance to Bt transgenic cotton: A case analysis

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Cotton bollworm (Helicoverpa armigera) is one of the most serious insect pests of cotton. Transgenic cotton expressing Cry toxins derived from a soil bacterium, Bacillus thuringiensis (Bt), has been produced to target this pest. Bt cotton has been widely planted around the world, and this has resulted in efficient control of bollworm populations with reduced use of synthetic insecticides. However, evolution of resistance by this pest threatens the continued success of Bt cotton. To date, no field populations of bollworm have evolved significant levels of resistance; however, several laboratory-selected Cry-resistant strains of H. armigera have been obtained, which suggests that bollworm has the capacity to evolve resistance to Bt. The development of resistance to Bt is of great concern, and there is a vast body of research in this area aimed at ensuring the continued success of Bt cotton. Here, we review studies on the evolution of Bt resistance in H. armigera, focusing on the biochemical and molecular basis of Bt resistance. We also discuss resistance management strategies, and monitoring programs implemented in China, Australia, and India.

  14. Arabidopsis EDT1/HDG11 improves drought and salt tolerance in cotton and poplar and increases cotton yield in the field.

    Science.gov (United States)

    Yu, Lin-Hui; Wu, Shen-Jie; Peng, Yi-Shu; Liu, Rui-Na; Chen, Xi; Zhao, Ping; Xu, Ping; Zhu, Jian-Bo; Jiao, Gai-Li; Pei, Yan; Xiang, Cheng-Bin

    2016-01-01

    Drought and salinity are two major environmental factors limiting crop production worldwide. Improvement of drought and salt tolerance of crops with transgenic approach is an effective strategy to meet the demand of the ever-growing world population. Arabidopsis ENHANCED DROUGHT TOLERANCE1/HOMEODOMAIN GLABROUS11 (AtEDT1/HDG11), a homeodomain-START transcription factor, has been demonstrated to significantly improve drought tolerance in Arabidopsis, tobacco, tall fescue and rice. Here we report that AtHDG11 also confers drought and salt tolerance in upland cotton (Gossypium hirsutum) and woody plant poplar (Populus tomentosa Carr.). Our results showed that both the transgenic cotton and poplar exhibited significantly enhanced tolerance to drought and salt stress with well-developed root system. In the leaves of the transgenic cotton plants, proline content, soluble sugar content and activities of reactive oxygen species-scavenging enzymes were significantly increased after drought and salt stress compared with wild type. Leaf stomatal density was significantly reduced, whereas stomatal and leaf epidermal cell size were significantly increased in both the transgenic cotton and poplar plants. More importantly, the transgenic cotton showed significantly improved drought tolerance and better agronomic performance with higher cotton yield in the field both under normal and drought conditions. These results demonstrate that AtHDG11 is not only a promising candidate for crops improvement but also for woody plants.

  15. Cadmium (Cd) Localization in Tissues of Cotton (Gossypium hirsutum L.), and Its Phytoremediation Potential for Cd-Contaminated Soils.

    Science.gov (United States)

    Chen, Zhifan; Zhao, Ye; Fan, Lidong; Xing, Liteng; Yang, Yujie

    2015-12-01

    Phytoremediation using economically valuable, large biomass, non-edible plants is a promising method for metal-contaminated soils. This study investigated cotton's tolerance for Cd and remediation potential through analyzing Cd bioaccumulation and localization in plant organs under different soil Cd levels. Results showed cotton presents good tolerance when soil Cd concentration ≤20.26 mg kg(-1). Cotton had good Cd accumulation ability under low soil Cd levels (soil Cd, while roots and stems were the main compartments of Cd storage. Cd complexation to other organic constituents in root and stem cell sap could be a primary detoxifying strategy. Therefore, cotton is a potential candidate for phytoremediation of Cd-contaminated soils.

  16. Biocontrol of verticillium wilt and colonization of cotton plants by an endophytic bacterial isolate.

    Science.gov (United States)

    Li, C-H; Shi, L; Han, Q; Hu, H-L; Zhao, M-W; Tang, C-M; Li, S-P

    2012-09-01

    To explore biocontrol potential of 39 DAEB isolates (doubly antagonistic towards both Verticillium dahliae Kleb and Fusarium oxysporum) against verticillium wilt of cotton and to elucidate colonization and category characteristics of an endophytic bacterium with significant biocontrol activity. Thirty-nine antagonistic endophytic bacteria strains were tested for their ability to control verticillium wilt in cotton plants caused by a defoliating pathotype of V. dahliae 107 in cotton under controlled conditions. The biocontrol trial revealed that an endophytic bacterium, designated HA02, showed a significant biocontrol activity to V. dahliae 107. After cotton seedlings were inoculated with a gfp gene-tagged HA02 (HA02-gfp), HA02-gfp populations were higher in the root than in the stem; in addition, the HA02-gfp was distributed in the maturation zone of cotton root. Furthermore, HA02-gfp also colonized seedlings of maize, rape and soybean after the bacteria inoculation. Phylogenetic trees based on 16S rDNA sequences combined with morphological, physiological and identification showed that the bacterium belongs to the Enterobacter genus. Our results showed that only 1 of 39 DAEB isolates demonstrated more efficient biocontrol potential towards V. dahliae 107 in greenhouse and field trials. HA02-gfp mainly colonized cotton in roots. In addition, we quantitatively observed HA02 colonization in other hosts. HA02 belongs to the Enterobacter genus. This is the first study on biocontrol to defoliating pathotype of V. dahliae Kleb by endophytic bacteria. The HA02 showed effective biocontrol to V. dahliae 107 in greenhouse and field trials. Furthermore, we assessed the quantitative and qualitative colonization of HA02 in cotton seedlings. Our study provides basic information to further explore managing strategies to control this critical disease. © 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  17. Evaluation of soybean genotypes for resistance to charcoal rot

    Science.gov (United States)

    Charcoal rot caused by Macrophomina phaseolina causes more yield loss in soybean than most other diseases in the southern U.S.A. There are no commercial genotypes marketed as resistant to charcoal rot of soybean. Reactions of 27 maturity group (MG) III, 29 Early MG IV, 34 Late MG IV, and 59 MG V gen...

  18. RotCFD Software Validation - Computational and Experimental Data Comparison

    Science.gov (United States)

    Fernandez, Ovidio Montalvo

    2014-01-01

    RotCFD is a software intended to ease the design of NextGen rotorcraft. Since RotCFD is a new software still in the development process, the results need to be validated to determine the software's accuracy. The purpose of the present document is to explain one of the approaches to accomplish that goal.

  19. Thermal control of some post-harvest rot pathogens of Irish potato (solanum tuberosum l.

    Directory of Open Access Journals (Sweden)

    Salami Olusola Abiodun

    2007-01-01

    Full Text Available Thermal control effect on the incidence of some post-harvest rot pathogens of Solanum tuberosum (potato was investigated in this study. Three cultivars of potato tuber whose local names are, Patiska, Mai Bawondoya and Nicola were used for the study. Five pathogenic fungi viz: Botryodiplodia theobromae, Fusarium redolens, Fusarium oxysporum, Penicillium sp. and Rhizopus oryzae associated with post harvest storage rot of root-tubers, were isolated from diseased potatoes. Among the three species of potatoes used in the study, Patiska was found most resistant followed by Mai Bawondoya, while Nicola was the least resistant. Increase in substrate (i.e. soluble starch or CMC concentration enhanced a proportional increase in mycelial growth and in the amount of extracellular enzymes produced. Some of these test pathogens were found to produce cell wall degrading enzymes (i.e. amylase and cellulase. Preferential utilization of carbohydrate sources was established in this study based on the growth of test pathogens. Growth on potato broth medium was highest followed by growth on Cocoyam and Sweet potato broth media and least on Cassava broth medium. Growth of the test pathogens on carbohydrate sources was found at variant. The use of hot water treatment at different temperatures was found to significantly reduce post-harvest fungal populations on the surface of root-tubers. The efficacy of blanching in hot water at 60˚C was significantly higher than that of blanching in hot water at other temperatures. The control method adopted in this study showed that the problems of potatoes’ rot disease in storage (especially by the peasant farmers can be eradicated by thermal treatments without reducing the quality of the Irish tuber.

  20. Recent advances in biological control of soil borne root diseases of wheat,vegetables and cotton in China and Australia%中国、澳大利亚小麦、蔬菜以及棉花根部土传病害生物防治研究进展

    Institute of Scientific and Technical Information of China (English)

    Maarten RYDER; Rosemary WARREN; Paul HARVEY; 唐文华; 杨合同; 张霞; 张炳新

    2005-01-01

    土传病害是作物产量的经常性限制因素.在禾谷类生产中,某些病害在少耕制度下异常严重.因此,有利于保护土壤侵蚀的管理措施(例如减少耕作、保留农作物残体等)能导致病害发生更为严重,从而造成作物减产,这要求研究新的病害防治措施,而不能依靠农业耕作措施或轮作进行防治.生物防治是病害防治措施的一种,在中国和澳大利亚都已进行了研究.蔬菜和棉花的苗期病害一般是利用化学杀菌剂进行防治,或者病害严重发生导致毁种后重新播种.在这些病害防治方面,人们探索了生物防治措施,旨在发展安全、无残留的防治方法,本文介绍的合作研究,主要是在田间和盆栽条件下筛选、评价一系列澳大利亚和中国的土壤细菌和真菌在中国和澳大利亚东南部对土传病害的防治作用,从而建立有效可靠的作物病害生物防治方法.在两国进行的实验研究中,对象作物为小麦、蔬菜(番茄、黄瓜和辣椒)以及棉花.另外,还对枯草芽孢杆菌的作用机理以及重要植物病原菌如腐霉菌的生态学进行了研究.%Soil-borne root diseases are often major constraints to crop productivity. In cereal production systems, some diseases become more serious under conservation (I.e.reduced) tillage regimes. Thus management practices (e.g. Reduced tillage and crop residue retention) which help prevent soil erosion problems can result in more serious yield losses due to disease. This has led to research on methods other than cultivation and crop rotation for disease control.Biological control is one alternative, which has been investigated in both China and Australia.In the vegetable and cotton growing industries, seedling diseases are controlled largely by chemical fungicides or crops are replanted if there is a failure of establishment. Hence, biological controls are sought in the interest of safer and cleaner methods of disease control

  1. Development and Validation of National Cotton Cultivar Registration lndex Model in Yangtze River Valley

    Institute of Scientific and Technical Information of China (English)

    Naiyin XU; Jian Ll

    2014-01-01

    Based on the cotton variety high yielding potential, fiber quality traits, disease resistance, and early maturity characters, a cultivar registration index model was developed to simplify the tedious calculation process in national cotton registration procedure, and thus to enhance the practical application of cultivar regis-tration index in cotton breeding and cotton recommending. [Method] By means of correlation analysis, partial correlation analysis and path analysis methods, the cor-relation of cotton main properties and their effects on cultivar registration index were explored using the dataset of national cotton regional trials in Yangtze River Val ey during 1996-2013. The cultivar registration index model was constructed with step-wise regression statistical technique to ascertain the quantitative relationship of main characters with cultivar registration index, and the regional cotton trial dataset in 2013 was used to validate the model. [Result] Several characters with larger deter-minants to cultivar registration index were screened out, i.e. lint yield increase ratio, pro-frost yield ratio, verticil ium wilt index, fiber strength, fusarium wilt index and mi-cronaire value. The cultivar registration index model defined the functional relation-ship of cultivar registration index with the selected main characters, among which lint yield increase ratio, fiber strength and micronaire value contributed most to culti-var registration index. The model validation with regional cotton trials in 2013 indi-cated the root mean square error, RMSE was only 2.77, and the variation coeffi-cient was 6.77%, which confirmed the model prediction effect was quite perfect. [Conclusion] The developed cultivar registration index model was reliable enough to simulate the complicated scoring system in cultivar registration procedure, also sim-plified cotton registration process, and enhanced the practicability of the cultivar reg-istration index.

  2. 7 CFR 28.471 - Below Leaf Grade Cotton.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than...

  3. 7 CFR 28.451 - Below Color Grade Cotton.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Below Color Grade Cotton. 28.451 Section 28.451... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Color Grade Cotton § 28.451 Below Color Grade Cotton. Below color grade cotton is American Upland cotton which is lower in color grade than...

  4. Island cotton Gbve1 gene encoding a receptor-like protein confers resistance to both defoliating and non-defoliating isolates of Verticillium dahliae.

    Directory of Open Access Journals (Sweden)

    Baolong Zhang

    Full Text Available Verticillium wilt caused by soilborne fungus Verticillium dahliae could significantly reduce cotton yield. Here, we cloned a tomato Ve homologous gene, Gbve1, from an island cotton cultivar that is resistant to Verticillium wilt. We found that the Gbve1 gene was induced by V. dahliae and by phytohormones salicylic acid, jasmonic acid, and ethylene, but not by abscisic acid. The induction of Gbve1 in resistant cotton was quicker and stronger than in Verticillium-susceptible upland cotton following V. dahliae inoculation. Gbve1 promoter-driving GUS activity was found exclusively in the vascular bundles of roots and stems of transgenic Arabidopsis. Virus-induced silencing of endogenous genes in resistant cotton via targeting a fragment of the Gbve1 gene compromised cotton resistance to V. dahliae. Furthermore, we transformed the Gbve1 gene into Arabidopsis and upland cotton through Agrobacterium-mediated transformation. Overexpression of the Gbve1 gene endowed transgenic Arabidopsis and upland cotton with resistance to high aggressive defoliating and non-defoliating isolates of V. dahliae. And HR-mimic cell death was observed in the transgenic Arabidopsis. Our results demonstrate that the Gbve1 gene is responsible for resistance to V. dahliae in island cotton and can be used for breeding cotton varieties that are resistant to Verticillium wilt.

  5. Biocontrol mechanisms of Trichoderma harzianum against soybean charcoal rot caused by Macrophomina phaseolina

    Directory of Open Access Journals (Sweden)

    Khaledi Nima

    2016-01-01

    Full Text Available Throughout the world, charcoal rot, caused by Macrophomina phaseolina, is one of the most destructive and widespread diseases of crop plants such as soybean. In this study, the biological control capability of 11 Trichoderma spp. isolates against M. phaseolina was investigated using screening tests. Among all the tested Trichoderma spp. isolates, inhibition varied from 20.22 to 58.67% in dual culture tests. Dual culture, volatile and non-volatile tests revealed that two isolates of Trichoderma harzianum (including the isolates T7 and T14 best inhibited the growth of M. phaseolina in vitro. Therefore, these isolates were selected for biocontrol of M. phaseolina in vivo. The results of greenhouse experiments revealed that disease severity in the seed treatment with T. harzianum isolates was significantly lower than that of the soil treatment. In most of the cases, though, soil treatment with T. harzianum resulted in higher plant growth parameters, such as root and shoot weight. The effects of T. harzianum isolates on the activity of peroxidase enzyme and phenolic contents of the soybean root in the presence and absence of M. phaseolina were determined in greenhouse conditions. Our results suggested that a part of the inhibitory effect of T. harzianum isolates on soybean charcoal rot might be related to the indirect influence on M. phaseolina. Plant defense responses were activated as an elicitor in addition to the direct effect on the pathogen growth.

  6. Jasmonic acid causes short- and long-term alterations to the transcriptome and the expression of defense genes in sugarbeet roots

    Science.gov (United States)

    Jasmonic acid (JA) induces native defense responses in plants and increases the resistance of postharvest sugarbeet roots to three common storage-rot causing organisms. To gain insight into the defense responses induced by JA in harvested sugarbeet roots, RNA was isolated from roots treated with wat...

  7. Prevalence of Erwinia soft rot affecting cut foliage, Dracaena sanderiana ornamental industry and solution towards its management.

    Science.gov (United States)

    Kayalvily, Thio Desiya; Jegathambigai, V; Karunarathne, M D S D; Svinningen, Arne; Mikunthan, G

    2012-01-01

    The study was carried out under net house conditions at Green Farms Ltd, Marawila to determine the occurrence and severity of Erwinia soft rot disease in Dracaena sanderiana plants and to formulate the possible control measures. Field experiment was carried out to manage the soft rot disease in D. sanderiana plants. Three different soil treatments with vermicompost, cow dung and poultry manure were tested to manage the disease and plots without application were kept as control. Percent disease incidence, disease reduction and growth parameters were recorded and data were statistically analyzed. Higher percentage of disease reduction was observed in vermicompost (80%) treated plots than those with cow dung (60%) and poultry manure treated. Sprinkler application of water was found favorable to spread soft rot disease and watering through horse pope had lessened the disease incidence significantly. Moreover plant height, shoot and root biomass, number of leaves per plant, leaf length and leaf width were significantly high in vermicompost media. Weeding, removal of diseased leaves and plants, and avoiding sprinkler irrigation were helpful to reduce the disease spread from plant to plant. Vermicompost is the best substrate for suppression of the disease and promoting the growth of plant. Among the different water management practices tested to reduce the disease severity of Erwinia soft rot disease in D. sanderiana plants, water irrigated through the horse pipe was effective compare to sprinkler application. In-vitro experiment conducted to manage the Erwinia soft rot disease by using bio-agent, Pseudomonas fluorescens was found effective to reduce the growth of Erwinia under in-vitro conditions.

  8. Cotton Cultivar Response to Temik 15G Plus Avicta in Two Tillage Regimes in Alabama, 2007

    Science.gov (United States)

    Six cotton cultivars were evaluated for yield response to the root-knot nematode in a naturally infested field at the Field Crops Unit of the E.V. Smith Research Center near Shorter, AL. Plots consisted of four rows, 50 feet long, with 3-foot row spacing and were planted in a factorial arrangement ...

  9. Evaluation of Variable Rate Application of Nematicides in Cotton According to Nematode Risk Zones

    Science.gov (United States)

    Cotton (Gossypium hirsutum L.) lint yield losses by southern root-knot nematode [Meloidogyne incognita] (RKN) have increased during the last 20 years. Site-specific management (SSM) of nematicides is a promising method to reduce yield losses, increase profitability and reduce adverse environmental i...

  10. Cotton Yield Response to Variable Rate Nematicides According to Risk Zones

    Science.gov (United States)

    Cotton (Gossypium hirsutum L.) lint yield losses by southern root-knot nematode [Meloidogyne incognita] (RKN) have increased during the last 20 years. Site-specific management (SSM) of nematicides is a promising method to reduce yield losses, increase profitability and reduce adverse environmental i...

  11. Effect of seed pelleting with biocontrol agents on growth and colonisation of roots of mungbean by root-infecting fungi.

    Science.gov (United States)

    Ramzan, Nadia; Noreen, Nayara; Perveen, Zahida; Shahzad, Saleem

    2016-08-01

    Mungbean (Vigna radiata (L.) Wilczek) is a leguminous pulse crop that is a major source of proteins, vitamins and minerals. Root-infecting fungi produce severe plant diseases like root rot, charcoal rot, damping-off and stem rot. The soil-borne pathogens can be controlled by chemicals, but these chemicals have several negative effects. Use of microbial antagonist such as fungi and bacteria is a safe, effective and eco-friendly method for the control of many soil-borne pathogens. Biological control agents promote plant growth and develop disease resistance. Application of bacteria and fungi as seed dressing suppressed the root-infecting fungi on leguminous crops. Seeds of mungbean were pelleted with different biocontrol agents to determine their effect on plant growth and colonisation of roots by root-infecting fungi, viz. Fusarium solani, Macrophomina phaseolina, Pythium aphanidermatum, Rhizoctonia solani and Sclerotium rolfsii. Treatment of mungbean seeds with fungal antagonists showed more shoot and root length as compared to bacterial antagonists, whereas seed treated with bacterial antagonists showed maximum shoot and root weight. Trichoderma harzianum and Bacillus subtilis were the best among all the biocontrol agents since they provided the highest plant growth and greater reduction in root colonisation by all root-infecting fungi. Bacillus cereus, Trichoderma virens, Pseudomonas fluorescens and Micrococcus varians were also effective against root-infecting fungi but to a lesser extent. T. harzianum, T. virens, B. subtilis and P. fluorescens were found to be best among all biocontrol agents. The root-infecting fungi can be controlled by pelleting seeds with biocontrol agents as it is safe and effective method. Additionally, plant growth was promoted more by this method. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  12. 75 FR 24373 - Cotton Research and Promotion Program: Designation of Cotton-Producing States

    Science.gov (United States)

    2010-05-05

    ... Federal Regulations is sold by the Superintendent of Documents. #0;Prices of new books are listed in the... Service 7 CFR Part 1205 RIN 0581-AC84 Cotton Research and Promotion Program: Designation of Cotton... Marketing Service (AMS) is amending the Cotton Research and Promotion Order (Cotton Order) following...

  13. GammaScorpion: mobile gamma-ray tomography system for early detection of basal stem rot in oil palm plantations

    Science.gov (United States)

    Abdullah, Jaafar; Hassan, Hearie; Shari, Mohamad Rabaie; Mohd, Salzali; Mustapha, Mahadi; Mahmood, Airwan Affendi; Jamaludin, Shahrizan; Ngah, Mohd Rosdi; Hamid, Noor Hisham

    2013-03-01

    Detection of the oil palm stem rot disease Ganoderma is a major issue in estate management and production in Malaysia. Conventional diagnostic techniques are difficult and time consuming when using visual inspection, and destructive and expensive when based on the chemical analysis of root or stem tissue. As an alternative, a transportable gamma-ray computed tomography system for the early detection of basal stem rot (BSR) of oil palms due to Ganoderma was developed locally at the Malaysian Nuclear Agency, Kajang, Malaysia. This system produces high quality tomographic images that clearly differentiate between healthy and Ganoderma infected oil palm stems. It has been successfully tested and used to detect the extent of BSR damage in oil palm plantations in Malaysia without the need to cut down the trees. This method offers promise for in situ inspection of oil palm stem diseases compared to the more conventional methods.

  14. EXTRACELLULAR POLYSACCHARIDES OF POTATO RING ROT PATHOGEN

    Directory of Open Access Journals (Sweden)

    Shafikova Т.N.

    2006-03-01

    Full Text Available Many bacteria, including phytopathogenic ones produce extracellular polysaccharides or exopolysaccharides which are universal molecules. Causal agent of potato ring rot, Clavibacter michiganensis subspecies sepedonicus, secretes exopolysaccharides which role in pathogenesis is poorly investigated. The aim of our research is to ascertain the composition and structure of Clavibacter michiganensis subspecies sepedonicus exopolysaccharides. Exopolysaccharides of Clavibacter michiganensis subspecies sepedonicus are determined to consist of 4-6 anionic and neutral components which have molecular weights from 700 kDa. Glucose is a major monomer of polysaccharides and arabinose, rhamnose and mannose are minor monomers. Glucose is present in α-Dglucopyranose and β-D-glucopyranose configurations. Calcium is determined to be a component of exopolysaccharides. Components of exopolysaccharides of potato ring rot pathogen are probably capableto associate via calcium ions and other ionic interactions that may result in a change of their physiological activity. Further studies of Clavibacter michiganensis subspecies sepedonicus exopolysaccharides composition and structure can serve a base for the synthesis of their chemical analogues with elicitor action.

  15. Uncertainties Mounting, Cotton Price Becomes Volatile

    Institute of Scientific and Technical Information of China (English)

    Huang Junfei

    2010-01-01

    @@ In the domestic market, the unre-mitting foul weather has delayed cotton picking by two weeks with downgraded quality; in the inter-national market, factors such as sus-pension of cotton export in India and disaster-affecting cotton yield in Paki-stan have led to such a market anticipa-tion that cotton stock across the world is to show another decline trend in the upcoming year. The unanimous market anticipation has resulted in a surge in cotton price during the Mid-autumn Festival: the transaction price for un-loading cotton inventories has increased by nearly RMB 3,000/ton, the price for purchasing new cotton has gone beyond RMB 25,000/ton and the cost for the imported cotton with owned quota (effect shipment after the next Spring Festival)has exceeded RMB 21,000/ton.

  16. China International Cotton Conference Concluded in Xinjiang

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ The 2007 China International Cotton Conference was held on June 27-29 in Urumqi, Xinjiang Municipality, China. With the theme "China's Cotton Industry on WTO and It's Implications The Global Market".

  17. Synthesis of Cotton from Tossa Jute Fiber and Comparison with Original Cotton

    Directory of Open Access Journals (Sweden)

    Md. Mizanur Rahman

    2015-01-01

    Full Text Available Cotton fibers were synthesized from tossa jute and characteristics were compared with original cotton by using FTIR and TGA. The FTIR results indicated that the peak intensity of OH group from jute cotton fibers occurred at 3336 cm−1 whereas the peak intensity of original cotton fibers occurred at 3338 cm−1. This indicated that the synthesized cotton fiber properties were very similar to the original cotton fibers. The TGA result showed that maximum rate of mass loss, the onset of decomposition, end of decomposition, and activation energy of synthesized cotton were higher than original cotton. The activation energy of jute cotton fibers was higher than the original cotton fibers.

  18. Co-inoculation with rhizobia and AMF inhibited soybean red crown rot: from field study to plant defense-related gene expression analysis.

    Directory of Open Access Journals (Sweden)

    Xiang Gao

    Full Text Available BACKGROUND: Soybean red crown rot is a major soil-borne disease all over the world, which severely affects soybean production. Efficient and sustainable methods are strongly desired to control the soil-borne diseases. PRINCIPAL FINDINGS: We firstly investigated the disease incidence and index of soybean red crown rot under different phosphorus (P additions in field and found that the natural inoculation of rhizobia and arbuscular mycorrhizal fungi (AMF could affect soybean red crown rot, particularly without P addition. Further studies in sand culture experiments showed that inoculation with rhizobia or AMF significantly decreased severity and incidence of soybean red crown rot, especially for co-inoculation with rhizobia and AMF at low P. The root colony forming unit (CFU decreased over 50% when inoculated by rhizobia and/or AMF at low P. However, P addition only enhanced CFU when inoculated with AMF. Furthermore, root exudates of soybean inoculated with rhizobia and/or AMF significantly inhibited pathogen growth and reproduction. Quantitative RT-PCR results indicated that the transcripts of the most tested pathogen defense-related (PR genes in roots were significantly increased by rhizobium and/or AMF inoculation. Among them, PR2, PR3, PR4 and PR10 reached the highest level with co-inoculation of rhizobium and AMF. CONCLUSIONS: Our results indicated that inoculation with rhizobia and AMF could directly inhibit pathogen growth and reproduction, and activate the plant overall defense system through increasing PR gene expressions. Combined with optimal P fertilization, inoculation with rhizobia and AMF could be considered as an efficient method to control soybean red crown rot in acid soils.

  19. CCI President Participated in China Cotton Summit

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    On May 7-8 the 2010 China Cotton Summit and the International Cotton Fair were held in Sanya,Hainan Province,China.Mr.Wallace L.Darneille, the new president of Cotton Council International(CCI) made a special trip to China to participate in the event and present on the"cotton and textile supply and demand situation in the U.S."

  20. Use of a Digital Camera to Monitor the Growth and Nitrogen Status of Cotton

    Directory of Open Access Journals (Sweden)

    Biao Jia

    2014-01-01

    Full Text Available The main objective of this study was to develop a nondestructive method for monitoring cotton growth and N status using a digital camera. Digital images were taken of the cotton canopies between emergence and full bloom. The green and red values were extracted from the digital images and then used to calculate canopy cover. The values of canopy cover were closely correlated with the normalized difference vegetation index and the ratio vegetation index and were measured using a GreenSeeker handheld sensor. Models were calibrated to describe the relationship between canopy cover and three growth properties of the cotton crop (i.e., aboveground total N content, LAI, and aboveground biomass. There were close, exponential relationships between canopy cover and three growth properties. And the relationships for estimating cotton aboveground total N content were most precise, the coefficients of determination (R2 value was 0.978, and the root mean square error (RMSE value was 1.479 g m−2. Moreover, the models were validated in three fields of high-yield cotton. The result indicated that the best relationship between canopy cover and aboveground total N content had an R2 value of 0.926 and an RMSE value of 1.631 g m−2. In conclusion, as a near-ground remote assessment tool, digital cameras have good potential for monitoring cotton growth and N status.

  1. Sequencing the Cotton Genomes-Gossypium spp.

    Institute of Scientific and Technical Information of China (English)

    PATERSON Andrew H

    2008-01-01

    @@ The genomes of most major crops,including cotton,will be fully sequenced in the next fewyears.Cotton is unusual,although not unique,in that we will need to sequence not only cultivated(tetraploid) genotypes but their diploid progenitors,to understand how elite cottons have surpassedthe productivity and quality of their progenitors.

  2. Dielectric permitivity measurement of cotton lint

    Science.gov (United States)

    A technique was developed for making broad band measurements of cotton lint electrical permitivity. The fundamental electrical permitivity value of cotton lint at various densities and moisture contents; is beneficial for the future development of cotton moisture sensors as it provides a...

  3. 7 CFR 1205.308 - Cotton Board.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Cotton Board. 1205.308 Section 1205.308 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Research and Promotion Order Definitions § 1205.308 Cotton Board. Cotton Board means the...

  4. 7 CFR 1205.305 - Upland cotton.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Research and Promotion Order Definitions § 1205.305 Upland cotton. Upland cotton means all...

  5. Toward cotton molecular breeding: challenges and opportunities

    Science.gov (United States)

    Cotton (Gossypium spp) is the leading natural fiber in the global textile market, but progress in the development and applications of molecular tools to improve cotton lags behind other major crop plants. The slow progress is in part due to cotton's large complex allotetraploid genome of 26 partial...

  6. Characterization of a Cotton Fiber Gene Promoter

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Cotton fibers are unicellular trichomes derived from outer integument cells of the ovule.Our previously study showed that cotton R2R3 MYB transcript factor GaMYB2 could complement the Arabidopsis trichome mutant of glabra1(gl1),suggesting that cotton fiber initiation and Arabidopsis leaf

  7. Greige cotton comber noils for sustainable nonwovens

    Science.gov (United States)

    To increase utilization of cotton in value-added nonwoven products, a study was conducted to examine the feasibility of utilizing cotton textile processing/combing bye-product known as griege cotton comber noils. The study was conducted on a commercial-grade, textile-cum-nonwovens pilot plant and ha...

  8. Bioinspiration and Biomimicry: Possibilities for Cotton Byproducts

    Science.gov (United States)

    The byproducts from cotton gins have commonly been referred to as cotton gin trash or cotton gin waste primarily because the lint and seed were the main focus of the operation and the byproducts were a financial liability that did not have a consistent market. Even though the byproducts were called ...

  9. Root hairs

    NARCIS (Netherlands)

    Grierson, C.; Nielsen, E.; Ketelaar, T.; Schiefelbein, J.

    2014-01-01

    Roots hairs are cylindrical extensions of root epidermal cells that are important for acquisition of nutrients, microbe interactions, and plant anchorage. The molecular mechanisms involved in the specification, differentiation, and physiology of root hairs in Arabidopsis are reviewed here. Root hair

  10. Primary Studies on Cotton Telomere

    Institute of Scientific and Technical Information of China (English)

    LING Jian; PENG Ren-hai; WANG Kun-bo; WANG Chun-ying; SONG Guo-li; LIU Fang; LI Shao-hui; ZHANG Xiang-di; WANG Yu-hong

    2008-01-01

    @@ The Arabidopsis -type telomere sequence was amplified and cloned using the primers designed from the fragment which contained the telomere sequence in an Arabidopsis BAC.In situ hybridizations with cotton metaphase chromosomes,using the telomere as probe,it indicated that the signals were located at all chromosome ends of 7 diploid and 2 tetraploid cotton species.To identify the signals of FISH,the genome DNA of Xinhai 7,digested by Bal31 kinetics,was used in this study.

  11. Trade Statistics: Cotton Yarn & Fabric in Feb.

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Cotton is the single most important textile fiber in the world,accounting for nearly 40 percent of total world fiber production.While some 80 countries from around the globe produce cotton,the United States,China,and India together provide over half the world's cotton.This monthly update provides official CNTAC (China National Textile & Apparel Council ) data on China import and export of cotton yarn and cotton fabric,to show a general profile of China's foreign trade in current textile industry.

  12. Management of Fusarium corm rot of gladiolus (Gladiolus ...

    African Journals Online (AJOL)

    USER

    2010-07-26

    Jul 26, 2010 ... Developing disease suppressive soils by introducing allelopathic crop residue manage- ment takes time, but the benefits accumulate across ..... crop rotation on corm rots disease of Gladiolus. Sci. Hortic. 121: 218-222 ...

  13. Autochthonous white rot fungi from the tropical forest: Potential of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... Autochthonous white rot fungi from the tropical forest: Potential of Cuban ... organo-pollutants structurally similar to lignin (Pointing,. 2001). It has also ..... potentially have a positive action against complex pollution situations.

  14. Functional Investigation of a Cotton Fiber HOX Gene

    Institute of Scientific and Technical Information of China (English)

    GUAN Xue-ying; SHANGGUAN Xiao-xia; WANG Shui; WANG Ling-jian; CHEN Xiao-ya

    2008-01-01

    @@ Most of the plant homeodomain-containing proteins play important roles in regulating cell differentiation and organ development,and Arabidopsis GLABRA2 (GL2),a member of the class IV homeodomain-Leucine zipper (HD-ZIP) proteins,is a trichome and non-root hair cell regulator.We have analyzed several cotton homeodomain-containing proteins that belong to the class IV HD-ZIP family.One of them,GaHOX1,shows a high sequence identity to Arabidopsis GL2 (95% in the homeodomain and 64% overall).

  15. Cutinase promotes dry esterification of cotton cellulose.

    Science.gov (United States)

    Xiaoman, Zhao; Teresa, Matama; Artur, Ribeiro; Carla, Silva; Jing, Wu; Jiajia, Fu; Artur, Cavaco-Paulo

    2016-01-01

    Cutinase from Thermobifida fusca was used to esterify the hydroxyl groups of cellulose with the fatty acids from triolein. Cutinase and triolein were pre-adsorbed on cotton and the reaction proceeded in a dry state during 48 h at 35°C. The cutinase-catalyzed esterification of the surface of cotton fabric resulted in the linkage of the oleate groups to the glycoside units of cotton cellulose. The superficial modification was confirmed by performing ATR-FTIR on treated cotton samples and by MALDI-TOF analysis of the liquors from the treatment of the esterified cotton with a crude cellulase mixture. Modified cotton fabric also showed a significant increase of hydrophobicity. This work proposes a novel bio-based approach to obtain hydrophobic cotton.

  16. China's Cotton Policy and the Impact of China's WTO Accession and Bt Cotton Adoption on the Chinese and U.S. Cotton Sectors

    OpenAIRE

    Cheng Fang; Bruce A. Babcock

    2003-01-01

    In this paper we provide an analysis of China's cotton policy and develop a framework to quantify the impact of both China's World Trade Organization (WTO) accession and Bt (Bacillus thuringiensis) cotton adoption on Chinese and U.S. cotton sectors. We use a Chinese cotton sector model consisting of supply, demand, price linkages, and textiles output equations. A two-stage framework model provides gross cropping area and total area for cotton and major subsitute crops from nine cotton-produci...

  17. Cotton and Climate Change: Impacts and Options to mitigate and adapt.

    Science.gov (United States)

    Ton, P.

    2012-04-01

    Cotton & Climate change: Impacts and Options to mitigate and adapt. Climate change will have major impacts on cotton production and trade depending on production location. This report to be presented analyses the impacts of climate change on cotton production and trade in the main producing areas world-wide, and the options available to mitigate and to adapt to these impacts. Cotton production is both a contributor to climate change and subject to its impacts. Agricultural production, processing, trade and consumption contribute up to 40% of the world's emissions when forest clearance is included in the calculation. Cotton production contributes to between 0.3% and 1% of total global GHG emissions. Cotton has a certain resilience to high temperatures and drought due to its vertical tap root. The crop is, however, sensitive to water availability, particularly at the height of flowering and boll formation. Rising temperatures favour plant development, unless day temperatures exceed 32°C. New production areas may be established where cotton was not grown before. Increases in atmospheric CO2 will also favour plant development. In turn, increased pests, water stress, diseases, and weather extremes will pose adaptation challenges. Overall, the negative impacts of climate change on cotton production relate to the reduced availability of water for irrigation, in particular in Xinjiang (China), Pakistan, Australia and the western United States. Heat stress risks creating depressed yields in Pakistan in particular, while in other countries limited increases in temperatures could favour cotton plant growth and lengthen the cotton growing season. The impacts of climate change on rainfall will likely be positive in the Yellow River area (China), in India, the south-eastern United States and south-eastern Anatolia (Turkey). Impacts on rainfall in Brazil and West and Central Africa are unclear. Mitigation and adaptation to climate change in cotton production, as in agriculture

  18. Evaluation of bacteria isolated from rice rhizosphere for biological control of charcoal rot of sorghum caused by Macrophomina phaseolina (Tassi) Goid.

    Science.gov (United States)

    Gopalakrishnan, Subramaniam; Humayun, Pagidi; Kiran, Bandru Keerthi; Kannan, Iyer Girish Kumar; Vidya, Meesala Sree; Deepthi, Kanala; Rupela, Om

    2011-06-01

    A total of 360 bacteria, isolated from the rhizospheres of a system of rice intensification (SRI) fields, were characterized for the production of siderophore, fluorescence, indole acetic acid (IAA), hydrocyanic acid (HCN) and solubilization of phosphorus. Of them, seven most promising isolates (SRI-156, -158, -178, -211, -229, -305 and -360) were screened for their antagonistic potential against Macrophomina phaseolina (causes charcoal rot in sorghum) by dual culture assay, blotter paper assay and in greenhouse. All the seven isolates inhibited M. phaseolina in dual culture assay, whereas six isolates solubilized phosphorous (except SRI-360), all seven produced siderophore, four produced fluorescence (except SRI-178, -229 and -305), six produced IAA (except SRI-305) and five produced HCN (except SRI-158 and -305). In the blotter paper assay, no charcoal rot infection was observed in SRI-156-treated sorghum roots, indicating complete inhibition of the pathogen, while the roots treated with the other isolates showed 49-76% lesser charcoal rot infection compared to the control. In the antifungal activity test (in green house on sorghum), all the isolates increased shoot dry mass by 15-23% and root dry mass by 15-20% (except SRI-158 and -360), over the control. In order to confirm the plant growth-promoting (PGP) traits of the isolates, the green house experiment was repeated but, in the absence of M. phaseolina. The results further confirmed the PGP traits of the isolates as evidenced by increases in shoot and root dry mass, 22-100% and 5-20%, respectively, over the control. The sequences of 16S rDNA gene of the isolates SRI-156, -158, -178, -211, -229, -305 and -360 were matched with Pseudomonas plecoglossicida, Brevibacterium antiquum, Bacillus altitudinis, Enterobacter ludwigii, E. ludwigii, Acinetobacter tandoii and P. monteilii, respectively in BLAST analysis. This study indicates that the selected bacterial isolates have the potential for PGP and control of

  19. Comparative studies on thermochemical characterization of corn stover pretreated by white-rot and brown-rot fungi.

    Science.gov (United States)

    Zeng, Yelin; Yang, Xuewei; Yu, Hongbo; Zhang, Xiaoyu; Ma, Fuying

    2011-09-28

    The effects of white-rot and brown-rot fungal pretreatment on the chemical composition and thermochemical conversion of corn stover were investigated. Fungus-pretreated corn stover was analyzed by Fourier transform infrared spectroscopy and X-ray diffraction analysis to characterize the changes in chemical composition. Differences in thermochemical conversion of corn stover after fungal pretreatment were investigated using thermogravimetric and pyrolysis analysis. The results indicated that the white-rot fungus Irpex lacteus CD2 has great lignin-degrading ability, whereas the brown-rot fungus Fomitopsis sp. IMER2 preferentially degrades the amorphous regions of the cellulose. The biopretreatment favors thermal decomposition of corn stover. The weight loss of IMER2-treated acid detergent fiber became greater, and the oil yield increased from 32.7 to 50.8%. After CD2 biopretreatment, 58% weight loss of acid detergent lignin was achieved and the oil yield increased from 16.8 to 26.8%.

  20. 7 CFR 1427.165 - Eligible seed cotton.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Eligible seed cotton. 1427.165 Section 1427.165... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.165 Eligible seed cotton. (a) Seed cotton pledged as collateral for a loan must be tendered to CCC by...

  1. 6-Benzyladenine enhancement of cotton

    Science.gov (United States)

    The influence of applied plant growth regulators (PGR) on growth, development and yield in cotton (Gossypium hirsutum L. and Gossypium barbadense L.) has been studied for over half a century. Studies of PGR containing cytokinin alone or in combination with gibbererillins applied at the pinhead squa...

  2. Transgene Stacking in Cotton Improvement

    Institute of Scientific and Technical Information of China (English)

    YANG Ye-hua; WANG Xue-kui; YAO Ming-jing; FAN Yu-peng; GAO Da-yu

    2008-01-01

    @@ To date,more and more transgenic varieties of upland cotton (Gossypium hirsuturn L.) generated with transgenes,which derived from varies of alien species,are playing important role in agricultural production.Stacking of multi-transgenes has a potential for combining all the merits of distinct transgenic lines in a cultivar and possibly makes a significant contribution to cultivar improvement.

  3. Cocoa/Cotton Comparative Genomics

    Science.gov (United States)

    With genome sequence from two members of the Malvaceae family recently made available, we are exploring syntenic relationships, gene content, and evolutionary trajectories between the cacao and cotton genomes. An assembly of cacao (Theobroma cacao) using Illumina and 454 sequence technology yielded ...

  4. Anthraquinone dyes for superhydrophobic cotton.

    Science.gov (United States)

    Salabert, J; Sebastián, R M; Vallribera, A

    2015-09-28

    Water-repellent, self-cleaning and stain resistant textiles are of interest for industrial applications. Anthraquinone reactive dyes were covalently grafted onto cotton fabric surfaces obtaining bright colors with good wash-fastness properties and giving rise to breathable superhydrophobic textiles with self-cleaning properties.

  5. Transgene Stacking in Cotton Improvement

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To date,more and more transgenic varieties of upland cotton(Gossypium hirsutum L.) generated with transgenes,which derived from varies of alien species,are playing important role in agricultural production.Stacking of multi-transgenes has a potential for combining all the merits of distinct

  6. Future of Cotton in Nonwovens

    Science.gov (United States)

    Although cotton offers several positive attributes, such as absorbency of liquids, dyeability, transportation and dissipation of moisture for wear comfort, static-freedom, sustainability, biodegradability and bioconsumability, and the like, its use in nonwoven products has been minimal. In order to ...

  7. Cottonseed and cotton plant biomass

    Science.gov (United States)

    The cotton plant generates several marketable products as a result of the ginning process. The product that garners the most attention in regards to value and research efforts, is lint with cottonseed being secondary. In addition to lint and cottonseed, the plant material itself has a value that...

  8. Primary Studies on Cotton Telomere

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The Arabidopsis-type telomere sequence was amplified and cloned using the primers designed from the fragment which contained the telomere sequence in an Arabidopsis BAC.In situ hybridizations with cotton metaphase chromosomes,using the telomere as probe,it indicated that the signals

  9. Evaluation of natural plant extracts, antagonists and fungicides in controlling root rot, collar rot, fruit (brown rot and gummosis of citrus caused by Phytophthora spp. in vitro

    Directory of Open Access Journals (Sweden)

    G.P. Jagtap

    2012-07-01

    Full Text Available The results revealed that all the six bioagents tested in vitro applying dual culture technique against Phytophthora nicotianae, Phytophthora citrophthora and Phytophthora palmivora significantly inhibited the mycelial growth of the test pathogen over untreated control. However, bioagent, Trichoderma harzianum recorded minimum mean colony diameter (7.73 cm2 and highest inhibition (87.85% of mycelial growth of P. nicotianae over untreated control followed by the bioagent T. viride, T. koningii which recorded mean colony diameter of 9.95 cm2, 14.15 cm2 and mean mycelial inhibition of 84.36 %, 77.76%, respectively. Evaluation of different botanicals by Poisoned Food Technique showed that all plant extracts tested in vitro were found significantly effective in reducing the percentage mycelial growth of P. nicotianae, P. citrophthora and P. palmivora over untreated control. However, plant extract (@ 5, 10 and 15% of Garlic, recorded lowest mean colony diameter (47.45 mm and highest mean mycelial growth inhibition (47.26% followed by Neem, Onion which recorded the mycelial growth of 55.20 mm, 60.85 mm, and the mean mycelial growth inhibition of 38.65%, 32.38%, respectively. Results revealed that all the nine fungicides tested in vitro applying Poisoned Food Technique against P. nicotianae, P. citrophthora and P. palmivora significantly inhibited the mycelial growth of the test pathogen over untreated control. However, fungicide, Cymoxynil 8% + Mancozeb 64% (Curzate M-8 recorded minimum mean colony diameter (16.12 mm and maximum mean inhibition (82.09% of mycelial growth of the test pathogen over untreated control (mean colony diameter 90.00 mm and mean inhibition 0.00 followed by the fungicide Metalaxyl-M 4% + Mancozeb 64% (Ridomil Gold, Metyram (Polyram, which recorded mean colony diameter of 20.16 mm, 24.16 mm and mean mycelial inhibition of 77.59%, 73.14%, respectively.

  10. Identification and Pathogenicity of Phytopathogenic Bacteria Associated with Soft Rot Disease of Girasole Tuber

    Directory of Open Access Journals (Sweden)

    Mamdoh Ewis ISMAIL

    2012-02-01

    Full Text Available During 2010-2011 growing seasons six bacterial isolates were separated from naturally infected girasole plants tubers (Helianthus tuberosus L. cv. Balady, showing soft rot, collected from experimental Farm of the Faculty of Agriculture, in El-Minia University, Egypt. Pathogenicity tests showed various virulence for the bacteria isolated from girasole tubers, found pathogenic. These organisms were characterized as rod-shaped, Gram negative, ?-methyl-d-glucoside medium, reducing substances from sucrose, phos, phatase activity and deep cavities on pectate medium. Otherwise, diagnostic tests suggested that the pathogen was Erwinia carotovora ssp. carotovora. The isolated bacteria caused soft rot of wounded tubers when inoculated into tissues. The bacterial isolates were compared for their degree of pathogenicity as well as for differences in specific symptoms, induced in different hosts. The tested isolates could infect several host ranges, such as fruits of apricot, apple, olive, lemon, squash, eggplant and potato tubers, bulbs and garlic and onion cloves, roots radish, carrot, sweet potato and rape. On the other hand, no symptoms were exhibited on pods of bean and cowpea, faba bean, fruits of pepper and tomato. The extracts of experimentally diseased girasole tubers were active in pectinase and also in caboxymethyl cellulose at pH 6 compared to enzyme activities in healthy tissues. Also, the isolated bacteria increased the total and reducing sugars in infected tissues.

  11. Identification and Pathogenicity of Phytopathogenic Bacteria Associated with Soft Rot Disease of Girasole Tuber

    Directory of Open Access Journals (Sweden)

    Mamdoh Ewis ISMAIL

    2012-02-01

    Full Text Available During 2010-2011 growing seasons six bacterial isolates were separated from naturally infected girasole plants tubers (Helianthus tuberosus L. cv. �Balady�, showing soft rot, collected from experimental Farm of the Faculty of Agriculture, in El-Minia University, Egypt. Pathogenicity tests showed various virulence for the bacteria isolated from girasole tubers, found pathogenic. These organisms were characterized as rod-shaped, Gram negative, ?-methyl-d-glucoside medium, reducing substances from sucrose, phos, phatase activity and deep cavities on pectate medium. Otherwise, diagnostic tests suggested that the pathogen was Erwinia carotovora ssp. carotovora. The isolated bacteria caused soft rot of wounded tubers when inoculated into tissues. The bacterial isolates were compared for their degree of pathogenicity as well as for differences in specific symptoms, induced in different hosts. The tested isolates could infect several host ranges, such as fruits of apricot, apple, olive, lemon, squash, eggplant and potato tubers, bulbs and garlic and onion cloves, roots radish, carrot, sweet potato and rape. On the other hand, no symptoms were exhibited on pods of bean and cowpea, faba bean, fruits of pepper and tomato. The extracts of experimentally diseased girasole tubers were active in pectinase and also in caboxymethyl cellulose at pH 6 compared to enzyme activities in healthy tissues. Also, the isolated bacteria increased the total and reducing sugars in infected tissues.

  12. Response of cultivars of malanga (Xanthosoma sagittifolium (L. Schott to dry rot

    Directory of Open Access Journals (Sweden)

    Ernesto Espinosa Cuéllar

    2017-01-01

    Full Text Available Malanga (Xanthosoma sagittifolium (L. Schott is an important food crop for over 400 million people in the tropics and subtropics. In order to determine the response of different varieties of malanga Xanthosoma to dry rot, a series of experiments were conducted in the period between 2012 and 2014. The experiments were performed on loamy Soil at the National Research Institute in Tropical Crops and Roots (INIVIT. We determined the incidence and severity of damage, yields and percent of losses at harvest. The lowest values of incidence and the highest total return was achieved in clons ‘INIVIT MX-95-2’, ‘INIVIT MX-95-1’ and ‘INIVIT MX-2007’. Clones of malanga Xanthosoma belonging to the group purple, showed lower incidence that of white and yellow groups. These results will allow selecting cultivars of malanga with greater resistance to the dry rot and with this to diminish the losses in the harvest.

  13. QTLs for Resistance to Major Rice Diseases Exacerbated by Global Warming: Brown Spot, Bacterial Seedling Rot, and Bacterial Grain Rot.

    Science.gov (United States)

    Mizobuchi, Ritsuko; Fukuoka, Shuichi; Tsushima, Seiya; Yano, Masahiro; Sato, Hiroyuki

    2016-12-01

    In rice (Oryza sativa L.), damage from diseases such as brown spot, caused by Bipolaris oryzae, and bacterial seedling rot and bacterial grain rot, caused by Burkholderia glumae, has increased under global warming because the optimal temperature ranges for growth of these pathogens are relatively high (around 30 °C). Therefore, the need for cultivars carrying genes for resistance to these diseases is increasing to ensure sustainable rice production. In contrast to the situation for other important rice diseases such as blast and bacterial blight, no genes for complete resistance to brown spot, bacterial seedling rot or bacterial grain rot have yet been discovered. Thus, rice breeders have to use partial resistance, which is largely influenced by environmental conditions. Recent progress in molecular genetics and improvement of evaluation methods for disease resistance have facilitated detection of quantitative trait loci (QTLs) associated with resistance. In this review, we summarize the results of worldwide screening for cultivars with resistance to brown spot, bacterial seedling rot and bacterial grain rot and we discuss the identification of QTLs conferring resistance to these diseases in order to provide useful information for rice breeding programs.

  14. Inter-Simple Sequence Repeat (ISSR Markers to Study Genetic Diversity Among Cotton Cultivars in Associated with Salt Tolerance

    Directory of Open Access Journals (Sweden)

    Ali Akbar ABDI

    2012-11-01

    Full Text Available Developing salt-tolerant crops is very important as a significant proportion of cultivated land is salt-affected. Screening and selection of salt tolerant genotypes of cotton using DNA molecular markers not only introduce tolerant cultivars useful for hybridization and breeding programs but also detect DNA regions involved in mechanism of salinity tolerance. To study this, 28 cotton cultivars, including 8 Iranian cotton varieties were grown in pots under greenhouse condition and three salt treatments were imposed with salt solutions (0, 70 and 140 mM NaCl. Eight agronomic traits including root length, root fresh weight, root dry weight, chlorophyll and fluorescence index, K+ and Na+ contents in shoot (above ground biomass, and K+/Na+ ratio were measured. Cluster analysis of cultivars based on measured agronomic traits, showed �Cindose� and �Ciacra� as the most tolerant cultivars, and �B-557� and �43347� as the most sensitive cultivars of salt damage. A total of 65 polymorphic DNA fragments were generated at 14 inter-simple sequence repeat (ISSR loci. Plants of 28 cultivars of cotton grouped into three clusters based on ISSR markers. Regression analysis of markers in relation with traits data showed that 23, 33 and 30 markers associated with the measured traits in three salt treatments respectively. These markers might help breeders in any marker assisted selection program in order to improving cotton cultivars against salt stress.

  15. The Joint Action of Destruxins and Botanical Insecticides (Rotenone, Azadirachtin and Paeonolum Against the Cotton Aphid, Aphis gossypii Glover

    Directory of Open Access Journals (Sweden)

    Meiying Hu

    2012-06-01

    Full Text Available The joint action of destruxins and three botanical insecticides, rotenone (Rot, azadirachtin (Aza and paeonolum (Pae against the cotton aphid, Aphis gossypii, was bioassayed. In laboratory experiment, several synergistic groups of destruxins with botanical insecticides were found by means of Sun’s Co-toxicity Coefficients (CTC and Finney’s Synergistic Coefficient (SC. The best synergistic effect was discovered in the ratio group Des/Rot 1/9 with the CTC or SC and LC50 values of 479.93 or 4.8 and 0.06 μg/mL, respectively. The second and third synergistic effects were recorded in the ratio groups Des/Rot 7/3 and 9/1. Although the ratio groups Des/Aza 6/4, Des/Pae 4/6, 3/7 and 2/8 indicated synergism by Sun’s CTC, they were determined as additive actions by Finney’s SC. Additive actions were also found in most of the ratio groups, but antagonism were recorded only in three ratio groups: Des/Pae 9/1, 7/3 and 6/4. In greenhouse tests, the highest mortality was 98.9% with the treatment Des/Rot 1/9 at 0.60 μg/mL, meanwhile, the treatments Des/Pae 4/6 and Des/Aza 6/4 had approximately 88% mortality.

  16. Root fractures

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Christensen, Søren Steno Ahrensburg; Tsilingaridis, Georgios

    2012-01-01

    The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed.......The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed....

  17. Repression of hla by rot is dependent on sae in Staphylococcus aureus.

    Science.gov (United States)

    Li, Dongmei; Cheung, Ambrose

    2008-03-01

    The regulatory locus sae is a two-component system in Staphylococcus aureus that regulates many important virulence factors, including alpha-toxin (encoded by hla) at the transcriptional level. The SarA homologs Rot and SarT were previously shown to be repressors of hla in selected S. aureus backgrounds. To delineate the interaction of rot and sae and the contribution of sarT to hla expression, an assortment of rot and sae isogenic single mutants, a rot sae double mutant, and a rot sae sarT markerless triple mutant were constructed from wild-type strain COL. Using Northern blot analysis and transcriptional reporter gene green fluorescent protein, fusion, and phenotypic assays, we found that the repression of hla by rot is dependent on sae. A rot sae sarT triple mutant was not able to rescue the hla defect of the rot sae double mutant. Among the three sae promoters, the distal sae P3 promoter is the strongest in vitro. Interestingly, the sae P3 promoter activities correlate with hla expression in rot, rot sae, and rot sae sarT mutants of COL. Transcriptional study has also shown that rot repressed sae, especially at the sae P3 promoter. Collectively, our data implicated the importance of sae in the rot-mediated repression of hla in S. aureus.

  18. High-throughput sequencing of black pepper root transcriptome

    Directory of Open Access Journals (Sweden)

    Gordo Sheila MC

    2012-09-01

    Full Text Available Abstract Background Black pepper (Piper nigrum L. is one of the most popular spices in the world. It is used in cooking and the preservation of food and even has medicinal properties. Losses in production from disease are a major limitation in the culture of this crop. The major diseases are root rot and foot rot, which are results of root infection by Fusarium solani and Phytophtora capsici, respectively. Understanding the molecular interaction between the pathogens and the host’s root region is important for obtaining resistant cultivars by biotechnological breeding. Genetic and molecular data for this species, though, are limited. In this paper, RNA-Seq technology has been employed, for the first time, to describe the root transcriptome of black pepper. Results The root transcriptome of black pepper was sequenced by the NGS SOLiD platform and assembled using the multiple-k method. Blast2Go and orthoMCL methods were used to annotate 10338 unigenes. The 4472 predicted proteins showed about 52% homology with the Arabidopsis proteome. Two root proteomes identified 615 proteins, which seem to define the plant’s root pattern. Simple-sequence repeats were identified that may be useful in studies of genetic diversity and may have applications in biotechnology and ecology. Conclusions This dataset of 10338 unigenes is crucially important for the biotechnological breeding of black pepper and the ecogenomics of the Magnoliids, a major group of basal angiosperms.

  19. Reproduction of Meloidogyne incognita on Winter Cover Crops Used in Cotton Production.

    Science.gov (United States)

    Timper, Patricia; Davis, Richard F; Tillman, P Glynn

    2006-03-01

    Substantial reproduction of Meloidogyne incognita on winter cover crops may lead to damaging populations in a subsequent cotton (Gossypium hirsutum) crop. The amount of population increase during the winter depends on soil temperature and the host status of the cover crop. Our objectives were to quantify M. incognita race 3 reproduction on rye (Secale cereale) and several leguminous cover crops and to determine if these cover crops increase population densities of M. incognita and subsequent damage to cotton. The cover crops tested were 'Bigbee' berseem clover (Trifolium alexandrinum), 'Paradana' balansa clover (T. balansae), 'AU Sunrise' and 'Dixie' crimson clover (T. incarnatum), 'Cherokee' red clover (T. pratense), common and 'AU Early Cover' hairy vetch (Vicia villosa), 'Cahaba White' vetch (V. sativa), and 'Wrens Abruzzi' rye. In the greenhouse tests, egg production was greatest on berseem clover, Dixie crimson clover, AU Early Cover hairy vetch, and common hairy vetch; intermediate on Balansa clover and AU Sunrise crimson clover; and least on rye, Cahaba White vetch, and Cherokee red clover. In both 2002 and 2003 field tests, enough heat units were accumulated between 1 January and 20 May for the nematode to complete two generations. Both AU Early Cover and common hairy vetch led to greater root galling than fallow in the subsequent cotton crop; they also supported high reproduction of M. incognita in the greenhouse. Rye and Cahaba White vetch did not increase root galling on cotton and were relatively poor hosts for M. incognita. Only those legumes that increased populations of M. incognita reduced cotton yield. In the southern US, M. incognita can complete one to two generations on a susceptible winter cover crop, so cover crops that support high nematode reproduction may lead to damage and yield losses in the following cotton crop. Planting rye or Meloidogyne-resistant legumes as winter cover crops will lower the risk of increased nematode populations

  20. Assessment of the effect of silicon on antioxidant enzymes in cotton plants by multivariate analysis.

    Science.gov (United States)

    Alberto Moldes, Carlos; Fontão de Lima Filho, Oscar; Manuel Camiña, José; Gabriela Kiriachek, Soraya; Lia Molas, María; Mui Tsai, Siu

    2013-11-27

    Silicon has been extensively researched in relation to the response of plants to biotic and abiotic stress, as an element triggering defense mechanisms which activate the antioxidant system. Furthermore, in some species, adding silicon to unstressed plants modifies the activity of certain antioxidant enzymes participating in detoxifying processes. Thus, in this study, we analyzed the activity of antioxidant enzymes in leaves and roots of unstressed cotton plants fertilized with silicon (Si). Cotton plants were grown in hydroponic culture and added with increasing doses of potassium silicate; then, the enzymatic activity of catalase (CAT), guaiacol peroxidase (GPOX), ascorbate peroxidase (APX), and lipid peroxidation were determined. Using multivariate analysis, we found that silicon altered the activity of GPOX, APX, and CAT in roots and leaves of unstressed cotton plants, whereas lipid peroxidation was not affected. The analysis of these four variables in concert showed a clear differentiation among Si treatments. We observed that enzymatic activities in leaves and roots changed as silicon concentration increased, to stabilize at 100 and 200 mg Si L(-1) treatments in leaves and roots, respectively. Those alterations would allow a new biochemical status that could be partially responsible for the beneficial effects of silicon. This study might contribute to adjust the silicon application doses for optimal fertilization, preventing potential toxic effects and unnecessary cost.

  1. Analysis of the Cotton E6 Promoter

    Institute of Scientific and Technical Information of China (English)

    WU Aimin; LIU Jinyuan

    2005-01-01

    An E6 gene from sea island cotton (Gossypium barbadense) was expressed specifically in cotton fiber cells to transfer functions to cultivated species for better transgenic engineering. The regulatory activity of the E6 promoter region was then studied by isolating a 614-bp fragment of the 5'-flanking region from upland cotton (Gossypium hirsutum CRI-12) to produce a green fluorescent protein (GFP) reporter construct for analysis of tissue-specific expression in transgenic tobacco seedlings. Fluorescent analyses indicate that the relatively short E6 promoter is sufficient to direct green fluorescent protein expression specifically in the leaf trichomes (hair cells) of the transgenic tobacco plants. As cotton fibers are also unicellular trichomes that differentiate from epidermal cells of developing cotton ovules, the result suggests that the relatively short E6 promoter can serve as a fiber-specific expression promoter for genetic engineering to improve cotton fiber quality.

  2. Digieye Application In Cotton Colour Measurement

    Directory of Open Access Journals (Sweden)

    Matusiak Małgorzata

    2015-06-01

    Full Text Available Colour is one of the most important properties of cotton raw materials. It helps in determining and classifying the quality of fibres according to the Universal Cotton Standards. Organoleptic and instrumental techniques are applied to assess the color of cotton. Worldwide, the colour parameters of cotton are measured by the High Volume Instrument (HVI, which provides information on reflectance (Rd and yellowness (+b that is specific for cotton, but are not the typical and globally recognized colour characteristics. Usually, worldwide, the colour of textile products and other goods is assessed utilizing the spectrophotometer, which provides the colour data that is widely recognized and accepted by the CIE L*a*b* colour space. This paper discusses utilizing the DigiEye system to measure the colour parameters of cotton samples and compares the results with the colour parameters from the HVI.

  3. Maize Stalk Rot and Ear Rot in China%中国玉米茎基腐病和穗腐病研究进展

    Institute of Scientific and Technical Information of China (English)

    徐书法; 陈捷; 高增贵; 邹庆道; 纪明山; 刘海南

    2006-01-01

    This review provides a broad overview of etiology, mechanism of pathogenesis and host resistance and IPM strategies involved in maize stalk rot and ear rot diseases in China. Some different viewpoints in the past are discussed in etiology of stalk rot occurring in China. The relation of both diseases is particularly evaluated based on Fusarium polymorphism analysis at the level of soluble protein, serology, isozymes and DNA, which are also further analyzed in accordance with the knowledge obtained by tracing pathogen infection process within the host root and stem tissue and trapping airborne spores nearby corn plants in the field. The recent researches of both diseases are summarized in physiological and biochemical mechanism of host resistance and resistant genetics, as well as IPM measures centered mainly in the application of biological control agents are summarized.%本文综述了我国在玉米茎基腐病和穗腐病病原学、致病性和寄主抗性机制与综合治理的研究进展.深入探讨了以往我国学者关于引起茎基腐病病原学的不同观点.根据2种病害的病原镰孢菌在可溶性蛋白质、血清学、同功酶和DNA等不同水平的多态性分析,镰孢菌在寄主根和茎组织内侵染过程示踪和孢子捕捉试验结果,重点讨论了2种镰孢菌病害在病原学侵染规律方面的相互关系,概述了2种病害寄主抗性生理生化机理、抗性遗传和以生物防治为核心的综合治理措施研究进展.

  4. Study on Spatial-temporal Dynamics of Bt Toxic Protein Expression in Insect-resistant Transgenic Cotton and Its Degradation in Soil

    Institute of Scientific and Technical Information of China (English)

    Yiwen ZHANG; Lianrong WANG; Liancheng ZHANG; Jun ZHANG; Xinbo JI; Jinmao WANG

    2012-01-01

    [Ob.jcctive] This study aimed to investigate the spatial-temporal dynamics of Bt toxic protein expression in insect-resistant transgenic cotton and its degradation in soil. [Meth~d] BtcrylAc toxic protein expression in roots, stems and leaves of trans- genic cotton Guoshen GK45 at different developmental stages and the annual aver- age content of BtCrylAc toxin protein in the topsoil, rhizosphere soil and following cotton-growing area were explored and analyzed by using enzyme linked immuno sorbed assay (ELISA). [Result] The content of exogenous BtCrylAc toxin protein de- creased during the growth process of insect-resistant transgenic cotton; to be specif- ic, the content of BtCrylAc toxin protein in cotton stems and leaves decreased more slowly and always maintained a high level, while that in roots decreased rapidly and reached a minimum level to the following plant growth and development stage. BtCrylAc toxin protein was detected in topsoil of both non-transgenic and transgenic cotton-growing areas, and the content of BtCrylAc toxin protein increased in topsoil of following cotton-growing area, which was very low in rhizosphere soil. [Conclusion] Determination of BtcrylAc toxic protein provides scientific basis for the risk assess- ment of the cultivation of genetically modified crops and the safety evaluation of soil ecosystem.

  5. Control of storage rot by induction of plant defense mechanisms using jasmonic acid and salicylic acid

    Science.gov (United States)

    Storage rots contribute to sugarbeet postharvest losses by consuming sucrose and producing carbohydrate impurities that increase sugar loss to molasses. Presently, storage rots are controlled by cooling storage piles. This method of control, however, requires favorable weather conditions for stora...

  6. 75 FR 50847 - Cotton Program Changes for Upland Cotton, Adjusted World Price, and Active Shipping Orders

    Science.gov (United States)

    2010-08-18

    ..., paper, or non-woven cotton fabric, the payment will be calculated on 25 percent of the weight (gross... further processing, for spinning, papermaking, or manufacture of non-woven cotton fabric, 25 percent of... definitions from the regulations for cotton non-recourse loans and loan deficiency payments. It clarifies...

  7. Impact of Groundwater Level on Nitrate Nitrogen Accumulation in the Vadose Zone Beneath a Cotton Field

    Directory of Open Access Journals (Sweden)

    Xiyun Jiao

    2017-02-01

    Full Text Available In this study, the impacts of groundwater level on nitrate nitrogen accumulation in the vadose zone of a cotton field were investigated. Experiments were conducted in a cotton field at the CAS Ecological Agricultural Experiment Station in Nanpi from 2008 to 2010. A vertical observation well was drilled, and time-domain reflectometry probes and soil solution extractors were installed every 50 cm in the walls of the well to a depth of 5 m. The soil water content was monitored, and soil solution samples were obtained and analyzed every six days throughout the growing seasons during the three studied years. Additionally, a water consumption experiment was conducted, and the topsoil water content and leaf area index were measured in the cotton field. The resulting data were used to estimate parameters for use in a soil hydraulic and nitrate nitrogen movement model, and cotton evapotranspiration was calculated using the Penman–Monteith method. Groundwater level increases and decreases of ±4 m were simulated during a ten-year period using HYDRUS-1D. The results showed significant nitrate nitrogen accumulation in the vadose zone when the groundwater level remained unchanged or decreased, with increased accumulation as the groundwater depth increased. Additionally, increased precipitation and a deeper groundwater level resulted in greater nitrate nitrogen leaching in the cotton root zone. Therefore, irrigation and fertilization strategies should be adjusted based on precipitation conditions and groundwater depth.

  8. Cotton in Benin: governance and pest management

    OpenAIRE

    Togbe, C.E.

    2013-01-01

    Key words: cotton, synthetic pesticides, neem oil (Azadirachta indica), Beauveria bassiana, Bacillus thuringiensis, field experiment, farmers’ participation   Pests are one of the main factors limiting cotton production worldwide. Most of the pest control strategies in cotton production rely heavily on the application of synthetic pesticides. The recurrent use of synthetic pesticides has large consequences for the environment (air, water, fauna, and flora) and human health. In cott...

  9. Cotton dust-mediated lung epithelial injury.

    OpenAIRE

    Ayars, G H; Altman, L C; O'Neil, C E; Butcher, B T; Chi, E Y

    1986-01-01

    To determine if constituents of cotton plants might play a role in byssinosis by injuring pulmonary epithelium, we added extracts of cotton dust, green bract, and field-dried bract to human A549 and rat type II pneumocytes. Injury was measured as pneumocyte lysis and detachment, and inhibition of protein synthesis. Extracts of cotton dust and field-dried bract produced significant dose- and time-dependent lysis and detachment of both target cells, while green bract extract was less damaging. ...

  10. Reaction of Cauliflower Genotypes to Black Rot of Crucifers

    Science.gov (United States)

    da Silva, Lincon Rafael; da Silva, Renan César Dias; Cardoso, Atalita Francis; de Mello Pelá, Gláucia; Carvalho, Daniel Diego Costa

    2015-01-01

    This study aimed to evaluate six cauliflower genotypes regarding their resistance to black rot and their production performance. To do so, it was conducted two field experiments in Ipameri, Goiás, Brazil, in 2012 and 2013. It was used a randomized block design, with four replications (total of 24 plots). Each plot consisted of three planting lines 2.5 m long (six plants/line), spaced 1.0 m apart, for a total area of 7.5 m2. Evaluations of black rot severity were performed at 45 days after transplanting, this is, 75 days after sowing (DAS), and yield evaluations at 90 to 105 DAS. The Verona 184 genotype was the most resistant to black rot, showing 1.87 and 2.25% of leaf area covered by black rot symptom (LACBRS) in 2012 and 2013. However, it was not among the most productive materials. The yield of the genotypes varied between 15.14 and 25.83 t/ha in both years, Lisvera F1 (21.78 and 24.60 t/ha) and Cindy (19.95 and 23.56 t/ha) being the most productive. However, Lisvera F1 showed 6.37 and 9.37% of LACBRS and Cindy showed 14.25 and 14.87% of LACBRS in 2012 and 2013, being both considered as tolerant to black rot. PMID:26060437

  11. Reaction of Cauliflower Genotypes to Black Rot of Crucifers

    Directory of Open Access Journals (Sweden)

    Lincon Rafael da Silva

    2015-06-01

    Full Text Available This study aimed to evaluate six cauliflower genotypes regarding their resistance to black rot and their production performance. To do so, it was conducted two field experiments in Ipameri, Goiás, Brazil, in 2012 and 2013. It was used a randomized block design, with four replications (total of 24 plots. Each plot consisted of three planting lines 2.5 m long (six plants/line, spaced 1.0 m apart, for a total area of 7.5 m². Evaluations of black rot severity were performed at 45 days after transplanting, this is, 75 days after sowing (DAS, and yield evaluations at 90 to 105 DAS. The Verona 184 genotype was the most resistant to black rot, showing 1.87 and 2.25% of leaf area covered by black rot symptom (LACBRS in 2012 and 2013. However, it was not among the most productive materials. The yield of the genotypes varied between 15.14 and 25.83 t/ha in both years, Lisvera F1 (21.78 and 24.60 t/ha and Cindy (19.95 and 23.56 t/ha being the most productive. However, Lisvera F1 showed 6.37 and 9.37% of LACBRS and Cindy showed 14.25 and 14.87% of LACBRS in 2012 and 2013, being both considered as tolerant to black rot.

  12. ROTS: An R package for reproducibility-optimized statistical testing.

    Science.gov (United States)

    Suomi, Tomi; Seyednasrollah, Fatemeh; Jaakkola, Maria K; Faux, Thomas; Elo, Laura L

    2017-05-01

    Differential expression analysis is one of the most common types of analyses performed on various biological data (e.g. RNA-seq or mass spectrometry proteomics). It is the process that detects features, such as genes or proteins, showing statistically significant differences between the sample groups under comparison. A major challenge in the analysis is the choice of an appropriate test statistic, as different statistics have been shown to perform well in different datasets. To this end, the reproducibility-optimized test statistic (ROTS) adjusts a modified t-statistic according to the inherent properties of the data and provides a ranking of the features based on their statistical evidence for differential expression between two groups. ROTS has already been successfully applied in a range of different studies from transcriptomics to proteomics, showing competitive performance against other state-of-the-art methods. To promote its widespread use, we introduce here a Bioconductor R package for performing ROTS analysis conveniently on different types of omics data. To illustrate the benefits of ROTS in various applications, we present three case studies, involving proteomics and RNA-seq data from public repositories, including both bulk and single cell data. The package is freely available from Bioconductor (https://www.bioconductor.org/packages/ROTS).

  13. DEGRADATION OF TEXTILE DYES BY WHITE ROT BASIDIOMYCETES

    Directory of Open Access Journals (Sweden)

    B.P. PARMAR, P.N. MERVANA B.R.M. VYAS*

    2014-12-01

    Full Text Available ABSTRACT: Dyes released by the textile industries pose a threat to environmental quality. Ligninolytic white-rot basidiomycetes can effectively degrade colored effluents and conventional dyes. White-rot fungi produce various isoforms of extracellular oxidases including laccase, Mn peroxidase and lignin peroxidase (LiP, which are involved in the degradation of lignin in their natural lignocellulosic substrates.  The textile industry, by far the most avid user of synthetic dyes, is in need of eco-efficient solutions for its colored effluents. White rot basidiomycetous fungi comprise the only group of organisms known to completely degrade lignin. Ligninolytic enzymes have potential applications in a large number of fields, including the chemical, fuel, food, agricultural, paper, textile, cosmetic industrial sectors and more. This ligninolytic system of white-rot fungi is also directly involved in the degradation of various xenobiotic compounds apart from textile dyes. Their capacities to remove xenobiotic substances make them a useful tool for bioremediation purposes. This paper reviews involvement of ligninolytic enzymes of white rot basidiomycetes in the degradation of textiles dyes and xenobiotic compounds for their industrial and biotechnological applications.

  14. Aqueous supercapacitors on conductive cotton

    KAUST Repository

    Pasta, Mauro

    2010-06-01

    Wearable electronics offer the combined advantages of both electronics and fabrics. In this article, we report the fabrication of wearable supercapacitors using cotton fabric as an essential component. Carbon nanotubes are conformally coated onto the cotton fibers, leading to a highly electrically conductive interconnecting network. The porous carbon nanotube coating functions as both active material and current collector in the supercapacitor. Aqueous lithium sulfate is used as the electrolyte in the devices, because it presents no safety concerns for human use. The supercapacitor shows high specific capacitance (~70-80 F·g-1 at 0.1 A·g-1) and cycling stability (negligible decay after 35,000 cycles). The extremely simple design and fabrication process make it applicable for providing power in practical electronic devices. © 2010 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

  15. Cotton Fever: Does the Patient Know Best?

    Science.gov (United States)

    Xie, Yingda; Pope, Bailey A; Hunter, Alan J

    2016-04-01

    Fever and leukocytosis have many possible etiologies in injection drug users. We present a case of a 22-year-old woman with fever and leukocytosis that were presumed secondary to cotton fever, a rarely recognized complication of injection drug use, after an extensive workup. Cotton fever is a benign, self-limited febrile syndrome characterized by fevers, leukocytosis, myalgias, nausea and vomiting, occurring in injection drug users who filter their drug suspensions through cotton balls. While this syndrome is commonly recognized amongst the injection drug user population, there is a paucity of data in the medical literature. We review the case presentation and available literature related to cotton fever.

  16. Precision mapping and identification of candidate genes for a QTL affecting Meloidogyne incognita reproduction in Upland cotton

    Science.gov (United States)

    The resistant line Auburn 623RNR and a number of elite breeding lines derived from it remain the most important source of root-knot nematode (RKN) resistance because they exhibit the highest level of resistance to RKN known to date in Upland cotton (Gossypium hirsutum L). Prior genetic mapping analy...

  17. QTL Analysis in Tetraploid Cotton

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    QTL analyses were performed in tetraploid cotton.An interspecific F2 population consisting of 69 plants,which was developed from the cross between Gossypium hirsutum L.,cv.Handan 208(characterized as high fiber yield) and G.barbadense L.,cv.Pima 90(characterized as excellent fiber quality),was genotyped with SSR,RAPD,SRAP,and REMAP markers.A 1029-locus linkage map was

  18. Shandong’s Cotton Brocade

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    SHANDONG Province, also called "Lu," produces traditional hand-woven cotton fabric known as "Lu Jin ("Jin" means brocade in Chinese). Lu Jin has a soft texture and is made in various designs and colors. Although machine-made cotton fabric is easy to buy here, local people, particularly women, prefer this kind of cloth woven in the old style handed down by their ancestors. In the countryside of Southwest Shandong, a girl usually begins learning how to weave cotton brocade as a child and old women are often still busy at the loom. In Jiaxiang County, for example, there are more than 10,400 looms, 74,000 spinning wheels and 90,000 capable weavers, producing 6 million meters of hand-woven fabric annually. Lu Jin is a suitable dowry for local girls. Usually, a girl begins selecting designs and weaving for her dowry two to three years before marriage. When she gets married, she carefully puts the fabric in the cupboards she will bring with

  19. Genetic variation between Phytophthora cactorum isolates differing in their ability to cause crown rot in strawberry

    NARCIS (Netherlands)

    Eikemo, H.; Klemsdal, S.S.; Riisberg, I.; Bonants, P.J.M.; Stensvand, A.; Tronsmo, A.M.

    2004-01-01

    Analysis of 44 isolates of Phytophthora cactorum, isolated from strawberry and other hosts, by AFLP showed that the crown rot pathotype is different from leather rot isolates and from P. cactorum isolated from other hosts. 16 of 23 crown rot isolates, including isolates from Europe, Japan, Australia

  20. Genetic variation between Phytophthora cactorum isolates differing in their ability to cause crown rot in strawberry

    NARCIS (Netherlands)

    Eikemo, H.; Klemsdal, S.S.; Riisberg, I.; Bonants, P.J.M.; Stensvand, A.; Tronsmo, A.M.

    2004-01-01

    Analysis of 44 isolates of Phytophthora cactorum, isolated from strawberry and other hosts, by AFLP showed that the crown rot pathotype is different from leather rot isolates and from P. cactorum isolated from other hosts. 16 of 23 crown rot isolates, including isolates from Europe, Japan, Australia

  1. Black rot of cabbage in The Netherlands: studies on spatial and temporal development.

    NARCIS (Netherlands)

    Kocks, C.G.

    1998-01-01

    Black rot in cabbage is caused by the bacterium Xanthomonas campestris pv. campestris . An exploratory survey at farm level suggested that major aspects contributing to black rot development are cultivar, initial inoculum, refuse management, origin of transplants, and seed quality. Black rot develop

  2. Biological Control of Phacidiopycnis Rot in ‘d’Anjou’ Pears

    Science.gov (United States)

    Phacidiopycnis rot, caused by Phacidiopycnis piri, is a recently reported postharvest fruit rot disease of pears (Pyrus) in the U.S. and a major disease of ‘d’Anjou’ pears grown in Washington State. Phacidiopycnis rot can originate from infection of wounds on the fruit. In this study, two biocontrol...

  3. Impacts of fungal stalk rot pathogens on physicochemical properties of sorghum grain

    Science.gov (United States)

    Stalk rot diseases are among the most ubiquitous and damaging fungal diseases of sorghum worldwide. Although reports of quantitative stalk rot yield losses are available, the impact of stalk rot on the physicochemical attributes of sorghum grain is currently unknown. This study was conducted to test...

  4. 越南对抗角斑病棉花品种的选育(英)%Screening of Promising Cotton Varieties for Bacterial Blight Resistance

    Institute of Scientific and Technical Information of China (English)

    Bui Thi Ngan

    2002-01-01

    @@ I Introduction Bacterial Blight (Xanthomonas malvacearum ,BB) was probably originated in India, although the disease was first reported in the USA by Atkinson (1891), who gave the names angular leaf spot, blackarm and bacterial boll rot to the various stages in the syndrome of the disease. The first programme to breed for cultivar resistance to the disease was initiated in Sudan by research officers with the Cotton Research Corporation. Methods adopted there were soon implemented in Uganda and most of the early resistant varieties grown in many African countries were derived from the Uganda programme.

  5. Rhizoctonia solani: Understanding the Terminology

    Science.gov (United States)

    Rhizoctonia solani can cause seedling damping-off and root rot in dry bean and a number of other major crops including sugarbeet, soybean, cotton, potato, etc. There appears to be an increase in reported incidence in both temperate regions and in tropical areas. As well as a root rot, some stains ca...

  6. The use of white-rot fungi as active biofilters

    Energy Technology Data Exchange (ETDEWEB)

    Braun-Luellemann, A.; Johannes, C.; Majcherczyk, A.; Huettermann, A. [Univ. Goettingen (Germany). Forstbotanisches Inst.

    1995-12-31

    White-rot fungi, growing on lignocellulosic substrates, have been successfully used as active organisms in biofilters. Filters using these fungi have a very high biological active surface area, allowing for high degrees of retention, a comparatively low pressure drop, and a high physical stability. The unspecific action of the extracellular enzymes of the white-rot fungi allows for the degradation of a wide variety of substances by the same organism. Degradation of several compounds in the gas phase by the white-rot fungi Trametes versicolor, Pleurotus ostreatus, Bjerkandera adusta, and Phanerochaete chrysosporium was tested. Among the aromatic solvents, styrene was the compound that was most readily degraded, followed by ethylbenzene, xylenes, and toluene. Tetrahydrofuran and dichloromethane were also degraded, whereas dioxane could not be attacked by fungi under the conditions used. Acrylonitrile and aniline were degraded very well, whereas pyridine was resistant to degradation. The process for removing styrene is now in the scaling-up stage.

  7. Decay threshold of acetylated rattan (Calamus manan) against soft rot

    Institute of Scientific and Technical Information of China (English)

    Norul Hisham Hamid; Mike Hale

    2013-01-01

    We investigated the resistance of acetylated rattan against soft rot and other soil inhabiting micro-organisms in comparison with wood of beech and Scots pine.Calamus manan of 10 and 13 years old under rubber tree canopy was acetylated to different levels by reaction times (0.25 to 30 hours) and was tested for soft rot decay for 32 weeks.Acetylated rattan at decay protection thresholds of 15.4% and 16.2% weight gain (WG) were fully protected,as shown by both weight loss and strength loss criteria.The static bending properties of untreated rattan decayed by soft rot were significantly lower than for acetylated rattan.

  8. Screening of Sweet Potato Germplasm Resources Resistant to Rot Nematode and Evaluation of Their Disease Resistance%甘薯抗茎线虫病种质资源的筛选与抗病性评价

    Institute of Scientific and Technical Information of China (English)

    孙厚俊; 赵永强; 谢逸萍; 陈晓宇; 邢继英

    2011-01-01

    对81份甘薯材料进行了茎线虫病、黑斑病和根腐病抗性鉴定和评价.结果表明:同时抗这3种病害的甘薯品种(系)较少,仅郑04-4-2和徐062826时甘薯茎线虫病抗侵入和抗扩展的同时,对黑斑病和根腐病也具有较高的抗性水平;另外有部分品种(系)如泰中7号、浙紫1号、徐060407等达到抗两病水平,可作为甘薯抗病育种的双抗亲本加以利用.%In this study, the resistances of 81 sweet potato germplasm resources to sweet potato rot nematode, black rot and root rot were identified and evaluated. The results indicated that very few sweet potato varieties (lines) could simultaneously resist these three diseases, only Zheng 04-4 -2 and Xu 062826 had high resistances not only to the invasion and expansion of rot nematode, but also to black rot and root rot. In addition, some tested resources such as Taizhong No. 7, Zhezi No. 1 and Xu 060407 had the double resistances, and they can be used as the double - resistant parents in the disease - resistant breeding of sweet potato.

  9. Fungicide seed treatment and host resistance for the management of wheat crown rot caused by Fusarium culmorum

    Directory of Open Access Journals (Sweden)

    Shree R Pariyar

    2014-11-01

    Full Text Available Seed treatment of wheat with the fungicide thiabendazole on the development of crown rot caused by Fusarium culmorum was evaluated on six wheat genotypes with different genetic sources of resistance under controlled conditions in a growth chamber. Seed of three susceptible (S cultivars, Seri 82 (Spring bread wheat, Kiziltan 91 (Winter durum Wheat, and Demir 2000 (Winter bread wheat and three moderately resistant (MR wheat lines, 2-49 (Spring bread wheat, Altay 2000 (Winter bread wheat, and Burbot-6 (Winter bread wheat were treated with thiabendazole at concentrations of 25, 50 and 100 g ai per 100 kg seeds. Thiabendazole seed treatment caused a significant (P< 0.05 reduction in severity of crown rot on 4 out of the 6 wheat genotypes. The highest crown score reduction was recorded on S genotypes Seri 82 and Demir 2000. Thiabendazole at 100 g ai per 100 kg seed gave the highest CS reduction on both the S and MR wheat genotypes. Seed coating with thiabendazole did not show any effect on plant height, plant weight, root length and root weight. No phytotoxicity symptoms were observed at any concentration of the fungicide.

  10. Incidence of crown rot disease of wheat caused by Fusarium pseudograminearum as a new soil born fungal species in north west Iran.

    Science.gov (United States)

    Saremi, H; Ammarellou, A; Jafary, H

    2007-10-15

    Root rot and crown rot is one of the main important fungal diseases on wheat in North West Iran. The disease was studied during 1999-2004 growing seasons in four provinces including Qazvin, Zanjan, East Azarbyjan and Ardabil. Different wheat fields in the areas studied were visited and samples of the plants showing symptoms like chlorosis, withering, whiting of spikes, growth reduction and white heads were collected and transferred to the laboratory. Samples were surface sterilized with sodium hypochlorite and then cultured on common media (PDA) and specific media (PPA and CLA). Totally 155 fungal isolates belonging to five genera were identified and the pathogen most frequently isolated was Fusarium pseudograminearum (formerly known as F. graminearum Group 1). This species normally causes crown rot resulting in severe damage in several locations under dry spring conditions. The disease caused losses from 18-45.5% in the fields where the season and crop rotation allowed the disease to build up. Prolonged moisture stresses coupled with relatively high soil temperature in the fall enhanced early disease development on the roots and sub crown internodes. Environmental conditions and genetic susceptibility of cultivars were the two main factors affecting diseases incidence.

  11. Physiological mechanisms involved in resistance to cotton verticillium wilt induced by AM fungi

    Institute of Scientific and Technical Information of China (English)

    LIU Bing-jiang; LIU Run-jin

    2004-01-01

    @@ It was proved that arbuscular mycorrhizal (AM) fungi played an important role in increasing plant resistance to soilborne pathogens, especially when plants were pre-inoculated with AM fungi.Mechanisms involved in this phenomenon are not yet well understood. On the basis of the former experiment results in our lab, effects of AM fungi on cotton Verticillium wilt and the mechanisms of increasing disease resisitance by the tested fungi were studied in pot culture under greenhouse conditions. Two cotton cutivars Litai 8 and 86-1 which are susceptible to Verticillium dahliae were pre-inoculated with Glomus fasiculatum, and Gigaspora margarita, then inoculated with the strain of Verticillium dahliae, namely "An-Yang" (belong to intermediate virulent type) 30 days after the former inoculation. Results showed that AM fungi could improve the growth and development of cotton plants, increase plants dry mass, decrease incidence and disease index of Verticillium wilt of cotton plants, inhibit the infection and development of V. dahliae to different extent in the rhizosphere of cotton pre-inoculated with AM fungi, while the colonization and spore numbers of AM fungi were not reduced significantly by this pathogen. The defence enzymes, such as phenylalanine ammonia-lyase (PAL), chitinase, β-1, 3-glucanase, peroxidase, polyphenoloxidase (PPO) were induced, and their activities and peak increased by AM fungi in roots and leaves, and the increasing speed and peak of the enzyme activity were higher in treatment with AM fungus preinoculation than the inoculation with only V. dahliae, which suggested that defense response was activated by AM fungi, and then made the cotton to react strongly and rapidly to the infection of V. dahliae. In addition, AM fungi decreased the content of malondiadehyde (MDA) in cotton roots and leaves,protected membrane system and alleviated the damage caused by the pathogen. The AM fungus,Glomus fasiculatum showed the superior effects of biological

  12. BIOCHEMICAL PULPING OF REED PRETREATED BY WHITE ROT FUNGI

    Institute of Scientific and Technical Information of China (English)

    ShiyuFu; AniwarApiz; HuaiyuZhan

    2004-01-01

    The Soda-AQ pulps were made from reed pretreated by white rot fungi Panus conchatus. Cyathus stercoreus and Pleurotus florida respectively. It was found that kappa number decreased and the brightness increased for Soda-AQ pulps from the reed treated by Pleurotus florida and Panus conchatus, but it was reverse for the pulp from reed treated by Cyathus stercoreus. The result indicated that white rot fungi Pleurotus .florida and Panus conchatus were selective to degrade lignin inreed, which were good for biopulping, but Cyathus stercoreus was preferential to degrade cellulose, which was not good for biopulping.

  13. BIOCHEMICAL PULPING OF REED PRETREATED BY WHITE ROT FUNGI

    Institute of Scientific and Technical Information of China (English)

    Shiyu Fu; Aniwar Apiz; Huaiyu Zhan

    2004-01-01

    The Soda-AQ pulps were made from reed pretreated by white rot fungi Panus conchatus,Cyathus stercoreus and Pleurotus florida respectively. It was found that kappa number decreased and the brightness increased for Soda-AQ pulps from the reed treated by Pleurotus florida and Panus conchatus, but it was reverse for the pulp from reed treated by Cyathus stercoreus. The result indicated that white rot fungi Pleurotus florida and Panus conchatus were selective to degrade lignin in reed, which were good for biopulping, but Cyathus stercoreus was preferential to degrade cellulose,which was not good for biopulping.

  14. Influence of Soil Temperature on Meloidogyne incognita Resistant and Susceptible Cotton, Gossypium hirsutum

    OpenAIRE

    Carter, William W.

    1982-01-01

    The degree of resistance by a cotton plant to Meloidogyne incognita is affected by soil temperature, particularly in moderately resistant cultivars, The total number of nematodes in the resistant and moderately resistant rools at 35 C was equal to, or greater than, the number in susceptible roots at 20, 25, or 30 C. A shift in numbers to developing and egg-bearing forms of nematodes in the susceptible cultivar as tentperature increased indicates development was affected by temperature rather ...

  15. Caging antimicrobial silver nanoparticles inside cotton

    Science.gov (United States)

    In this study, a stable, non-leaching Ag-cotton nanocomposite fiber has been characterized. Siver nanoparticles (Ag NPs) were previously synthesized in the alkali-swollen substructure of cotton fiber; the nano-sized micofibrillar channels allowed diffusion-controlled conditions to produce mono-dispe...

  16. 6-Benzyladenine enhancements of cotton yield

    Science.gov (United States)

    The influence of applied plant growth regulators (PGR) on growth, development and yield in cotton (Gossypium hirsutum L. and Gossypium barbadense L.) has been studied for over half a century. A recent study suggested that cytokinin treatment of young cotton seedlings may enhance overall performanc...

  17. 29 CFR 1910.1043 - Cotton dust.

    Science.gov (United States)

    2010-07-01

    ... of the instrument must have a means of correcting volumes to body temperature saturated with water... 29 Labor 6 2010-07-01 2010-07-01 false Cotton dust. 1910.1043 Section 1910.1043 Labor Regulations...), U.S. Department of Health and Human Services, or designee. Equivalent Instrument means a cotton dust...

  18. Exploring Modifications of Cotton with Biopolymers

    Science.gov (United States)

    Biopolymers including starch, alginate, and chitosan were grafted on to both nonwoven and woven cotton fabrics to examine their hemostatic and antimcrobial properties. The development of cotton-based health care fabrics that promote blood clotting and prevent microbial growth have wide applicability...

  19. China Cotton Situation Report [June 2007

    Institute of Scientific and Technical Information of China (English)

    James H. Zhao

    2007-01-01

    @@ The domestic cotton supply plus import quota released in due time can meet with spinners need in this season as can be assured by the fact that the spring sowing of cotton is finished in May, and summer sowing progresses well on its move.

  20. China International Cotton Conference Concluded in Xinjiang

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The 2007 China International Cotton Conference was held on June 27-29 in Urumqi,Xinjiang Municipality, China.With the theme"China’s Cotton Industry on WTO and It’s Implications The Global Market".the Conference proceeded with three main sessions,one focusing on the

  1. Australia: round module handling and cotton classing

    Science.gov (United States)

    Round modules of seed cotton produced via on-board module building harvesters are the reality of the cotton industry, worldwide. Although round modules have been available to the industry for almost a decade, there is still no consensus on the best method to handle the modules, particularly when th...

  2. The U.S. Cotton Industry.

    Science.gov (United States)

    Starbird, Irving R.; And Others

    This report identifies and describes the structure and performance of the cotton industry, emphasizing the production and marketing of raw cotton. The underlying economic and political forces causing change in the various segments of the industry are also explored. The report provides a single source of economic and statistical information on…

  3. Design of starch coated seed cotton dryers

    Science.gov (United States)

    A model was developed for the design and analysis of a high temperature tunnel dryer, primarily used with a new cotton ginning product, EASIflo ® cottonseed (starch-coated cottonseed). This form of cottonseed has emerged as a viable, value-added product for the cotton ginning industry. Currently, li...

  4. Scouring Process of Natural Color Cotton Products

    Institute of Scientific and Technical Information of China (English)

    XU Wei

    2002-01-01

    In order to improve the absorbency of color cotton products, alkali and pectase scouring processes under different conditions were tested, by comparing the actual results of two different scouring processes. It was considered that the pectase scouring process more suits color cotton products.

  5. Palmer amaranth competition for water in cotton

    Science.gov (United States)

    Palmer amaranth is a troublesome weed in cotton production. Yield losses of 65% have been reported due to season-long Palmer amaranth competition with cotton. To determine if water is a factor in this system, experiments were conducted in 2011, 2012, and 2013 in Citra, FL and in Tifton, GA. In 2011,...

  6. Import and Export for Cotton Textile Shrinking

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Recently, the National Development and Reform Committee held a meeting to discuss the preparation work of this year's new cotton storage. The meeting declared clearly the policy for this year's new cotton store up, namely starting from September 1, at the fixed price of CNY 19800 per ton, making the purchase without limitation.

  7. Flame retardant cotton based highloft nonwovens

    Science.gov (United States)

    Flame retardancy has been a serious bottleneck to develop cotton blended very high specific volume bulky High loft fabrics. Alternately, newer approach to produce flame retardant cotton blended High loft fabrics must be employed that retain soft feel characteristics desirable of furnishings. Hence, ...

  8. Antibacterial flame retardant cotton high loft nonwovens

    Science.gov (United States)

    Renewable resources for raw materials and biodegradability of the product at the end of the useful life is entailing a shift from petroleum-based synthetics to agro based natural fibers such as cotton, especially for producing high specific volume high loft nonwovens. Cotton is highly flammable and ...

  9. 77 FR 19925 - Upland Cotton Base Quality

    Science.gov (United States)

    2012-04-03

    ... Commodity Credit Corporation (CCC) upland cotton marketing assistance loan (MAL) regulations to revise... creates technical problems if the loan schedules and base grade specifications are changed. CCC... cotton industry to the USDA Agricultural Marketing Service (AMS). AMS can and does change...

  10. Spectroscopic discernment of seed cotton trash

    Science.gov (United States)

    Detection and identification of foreign material in harvested seed cotton is required for efficient removal by ginning. Trash particles remaining within the cotton fibers can detrimentally impact the quality of resulting textile products. Luminescence has been investigated as a potential tool for su...

  11. Milkweed, stink bugs, and Georgia cotton

    Science.gov (United States)

    In peanut-cotton farmscapes in Georgia, stink bugs, i.e., Nezara viridula (L.)(Say) and Chinavia hilaris (Say), develop in peanut and then disperse at the crop-to-crop interface to feed on fruit in cotton. The main objective of this study was to examine the influence of a habitat of tropical milkwe...

  12. Proteomics Study of Cotton Fiber Cells

    Institute of Scientific and Technical Information of China (English)

    LIU Jin-yuan

    2008-01-01

    @@ A comparative proteomic analysis was applied to explore the mechanism of fiber cell development in cotton.Initially,an efficient protein preparation method was established for proteomic analysis of developing cotton fibers by two-dimensional gel electrophoresis,and a microwave enhanced ink staining technique also was created for fast and sensitive protein quantification in proteomic studies.

  13. Repression of hla by rot Is Dependent on sae in Staphylococcus aureus▿

    OpenAIRE

    Li, Dongmei; Cheung, Ambrose

    2008-01-01

    The regulatory locus sae is a two-component system in Staphylococcus aureus that regulates many important virulence factors, including alpha-toxin (encoded by hla) at the transcriptional level. The SarA homologs Rot and SarT were previously shown to be repressors of hla in selected S. aureus backgrounds. To delineate the interaction of rot and sae and the contribution of sarT to hla expression, an assortment of rot and sae isogenic single mutants, a rot sae double mutant, and a rot sae sarT m...

  14. Geographic differentiation of Pseudomonas brassicacearum populations and bio-control of take-all disease of wheat and Pythium root rot of canola%Pseudomonas brassicacearum的数量分布差异及生物防治小麦全蚀病和油菜根腐病

    Institute of Scientific and Technical Information of China (English)

    P. R. HARVEY; R. A. WARREN; W. ACHOUAK; M. H. RYDER

    2005-01-01

    Strains representing populations of Pseudomonas brassicacearum from two contrasting South Australian wheat field soils were characterised by 3 PCR-based genotyping techniques and 3 phenotypic traits. Populations were highly diverse and significant levels of genotypic and bacterial-haplotype differentiation (GST and X2) were observed between the two geographical and two root-zone (i.e. rhizoplane and rhizosphere) populations(P<0.05).Three quarters of all strains had unique haplotypes and greater than 90% of these were specific to their population of origin. The average haplotype similarity among all strains was low (22%) and cluster analysis provided no evidence of relatedness on geographical origin or position in the root zone. These analyses indicate restrictions to inter-population gene flow and suggest that differentiation was due to random genetic drift and rhizoplane-based genotypic selection associated with the contrasting soils. One third of all strains tested positive for the 2,4-diacetylphloroglucinol biosynthesis gene(PhlD) and formed a related group (60% similarity).Four PhlD-positive strains(two wild types and their phenotypic variants) gave significant (P<0.05) bio-control of wheat take-all disease and Pythium damping-off of canola,indicating potential to control root disease complexes caused by these pathogens.%通过3种PCR技术测定基因特征和测定3种生化特征,对来自南澳洲两块对比小麦田土壤中的Pseudomonas brassicacearum种群的菌株进行了分析研究.结果显示,两种不同土壤和两种不同根部区域(根表和根际),该种群具有高度多样性,其基因型和基因组也具有显著差异(P<0.05).所分离到的菌株中,四分之三具有独特的基因组,90%以上的基因组是其原种群所独具有的.所有菌株的基因组的平均同源性比较低(22%),聚类分析不能证明来自不同小麦田和不同根部区域的菌株具有亲缘性.聚类分析显示,种群内的基因流动是受

  15. Root Infection and Systemic Colonization of Maize by Colletotrichum graminicola▿

    Science.gov (United States)

    Sukno, Serenella A.; García, Verónica M.; Shaw, Brian D.; Thon, Michael R.

    2008-01-01

    Colletotrichum graminicola is a filamentous ascomycete that causes anthracnose disease of maize. While the fungus can cause devastating foliar leaf blight and stalk rot diseases, little is known about its ability to infect roots. Previously published reports suggest that C. graminicola may infect maize roots and that root infections may contribute to the colonization of aboveground plant tissues, leading to disease. To determine whether C. graminicola can infect maize roots and whether root infections can result in the colonization of aboveground plant tissues, we developed a green fluorescent protein-tagged strain and used it to study the plant root colonization and infection process in vivo. We observed structures produced by other root pathogenic fungi, including runner hyphae, hyphopodia, and microsclerotia. A mosaic pattern of infection resulted from specific epidermal and cortical cells becoming infected by intercellular hyphae while surrounding cells were uninfected, a pattern that is distinctly different from that described for leaves. Interestingly, falcate conidia, normally restricted to acervuli, were also found filling epidermal cells and root hairs. Twenty-eight percent of plants challenged with soilborne inoculum became infected in aboveground plant parts (stem and/or leaves), indicating that root infection can lead to asymptomatic systemic colonization of the plants. Many of the traits observed for C. graminicola have been previously reported for other root-pathogenic fungi, suggesting that these traits are evolutionally conserved in multiple fungal lineages. These observations suggest that root infection may be an important component of the maize anthracnose disease cycle. PMID:18065625

  16. Root infection and systemic colonization of maize by Colletotrichum graminicola.

    Science.gov (United States)

    Sukno, Serenella A; García, Verónica M; Shaw, Brian D; Thon, Michael R

    2008-02-01

    Colletotrichum graminicola is a filamentous ascomycete that causes anthracnose disease of maize. While the fungus can cause devastating foliar leaf blight and stalk rot diseases, little is known about its ability to infect roots. Previously published reports suggest that C. graminicola may infect maize roots and that root infections may contribute to the colonization of aboveground plant tissues, leading to disease. To determine whether C. graminicola can infect maize roots and whether root infections can result in the colonization of aboveground plant tissues, we developed a green fluorescent protein-tagged strain and used it to study the plant root colonization and infection process in vivo. We observed structures produced by other root pathogenic fungi, including runner hyphae, hyphopodia, and microsclerotia. A mosaic pattern of infection resulted from specific epidermal and cortical cells becoming infected by intercellular hyphae while surrounding cells were uninfected, a pattern that is distinctly different from that described for leaves. Interestingly, falcate conidia, normally restricted to acervuli, were also found filling epidermal cells and root hairs. Twenty-eight percent of plants challenged with soilborne inoculum became infected in aboveground plant parts (stem and/or leaves), indicating that root infection can lead to asymptomatic systemic colonization of the plants. Many of the traits observed for C. graminicola have been previously reported for other root-pathogenic fungi, suggesting that these traits are evolutionally conserved in multiple fungal lineages. These observations suggest that root infection may be an important component of the maize anthracnose disease cycle.

  17. Cotton Textile:Brisk against Bleak

    Institute of Scientific and Technical Information of China (English)

    Dennis; K.Zhao

    2009-01-01

    The 6th International cotton and cotton textile conference already scheduled on Sept.8-10 in Xinjiang, China’s largest cotton growing area, was called off on a short notice of rascal needle dabbing that had caused a widespread public consternation. But the information that is focused on the leitmotif of "financial crisis and revitalization of textile industry for adjustment, upgrading and innovation" is to be shared, discussed at the upcoming resumed meeting. Cotton textile industry is and will be the most important driver for the global textile and clothing sector as it provides jobs not only for the residents living in the cities, but also for the farmers growing cotton in the poverty-ridden countryside. China and India are the most important players in this sector, for both are the most populous countries in the world…

  18. 7 CFR 1205.342 - Certification of cotton importer organizations.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Certification of cotton importer organizations. 1205... Organization § 1205.342 Certification of cotton importer organizations. Any importer organization may request... members to represent cotton importers on the Cotton Board. Such eligibility shall be based, in addition...

  19. 7 CFR 1205.317 - Cotton-Importer organization.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Cotton-Importer organization. 1205.317 Section 1205... RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.317 Cotton-Importer organization. Cotton-Importer organization means any organization which has been certified by the...

  20. Toward Elucidating the Structure of Tetraploid Cotton Genome

    Institute of Scientific and Technical Information of China (English)

    GUO Wang-zhen

    2008-01-01

    @@ Upland cotton has the highest yield,and accounts for >95% of world cotton production.Decoding upland cotton genomes will undoubtedly provide the ultimate reference and resource for structural,functional,and evolutionary studies of the species.Here,we employed GeneTrek and BAC tagging information approaches to predict the general composition and structure of the allotetraploid cotton genome.

  1. After Cotton Prices Hit a 10-Year Peak...

    Institute of Scientific and Technical Information of China (English)

    Wang Zhaofeng

    2010-01-01

    @@ "With the fifth-grade seed cotton being priced at 4.5 yuan per 500 grams and Xinjiang lint cotton at nearly RMB 20,000 per ton, cotton prices have rocketed to a 10-year peak," Gap Chaoshan, President of the Liaocheng Cotton Association, told the reporter on September 26.

  2. Coordination and collaboration to document the global cotton germplasm resources

    Science.gov (United States)

    Coordinated efforts to collect and maintain cotton genetic resources have increased over the last 100 years to insure the worldwide economic value of cotton fiber and cotton byproducts. The classified genetic resources of cotton are extensive and include five tetraploid species in the primary gene ...

  3. What Will We Do with a Cotton Genome Sequence?

    Institute of Scientific and Technical Information of China (English)

    BRUBAKER Curt

    2008-01-01

    @@ With the publication of "Toward Sequencing Cotton (Gossypium) Genomes" [Chen et al.PlantPhysiology,2007,145:1303-1310-] a clear consensus emerged from the cotton genomics community not only that cotton genome sequences were a critical resource for research and commercial innovationin cotton genomics,but that there was a logical means of achieving this goal.

  4. Study on the Pigments of the Colored Cotton

    Institute of Scientific and Technical Information of China (English)

    GU Zhao-wen; SHI Song-cun

    2004-01-01

    The ecological characteristics and fiber structure of the colored cotton were introduced briefly. The color changing mechanisms of the pigments extracted from colored cottons and some plants were discussed with the results of different experiments, which could offer an academic reference for the color fixations of the colored cotton textile produces and promote the development of the natural colored cotton industry.

  5. Test of pressure transducer for measuring cotton-mass flow

    Science.gov (United States)

    In this study, a cotton harvester yield monitor was developed based on the relationship between air pressure and the mass of seed cotton conveyed. The sensor theory was verified by laboratory tests. The sensor was tested on a cotton picker with seed cotton at two moisture contents, 5.9% and 8.5% we...

  6. QTL Analysis in Tetraploid Cotton

    Institute of Scientific and Technical Information of China (English)

    LIN Zhong-xu; HE Dao-hua; WANG Hong-mei

    2008-01-01

    @@ QTL analyses were performed in tetraploid cotton.An interspecific F2population consisting of 69 plants,which was developed from the cross between Gossypium hirsutum L.,cv.Handan 208 (characterized as high fiber yield) and G.barbadense L.,cv.Pima 90 (characterized as excellent fiber quality),was genotyped with SSR,RAPD,SRAP,and REMAP markers.A 1029-1ocus linkage map was constructed covering 5472.3 cM with an average distance of 5.32 cM between two markers.

  7. Superhydrophobic cotton by fluorosilane modification

    CSIR Research Space (South Africa)

    Erasmus, E

    2009-12-01

    Full Text Available in cotton is of great industrial importance due to the demanding consumer market for high performance textiles. It is not only a high value- added characteristic but it also has high commercial use and wide spectra of applications. Super- hydrophobicity... stream_source_info Erasmus1_2009.pdf.txt stream_content_type text/plain stream_size 7375 Content-Encoding UTF-8 stream_name Erasmus1_2009.pdf.txt Content-Type text/plain; charset=UTF-8 Indian Journal of Fibre & Textile...

  8. Testing of Cotton Fiber Length

    Institute of Scientific and Technical Information of China (English)

    刘若华; 李汝勤

    2001-01-01

    To understand the influences of actual sampling conditions on cotton fiber length testing, this article presents a theoretic study on the distributions and fibrogram of the sample taken out by sampler from ideal sliver at a certain angle. From the distributions expression it can be found that the size of the sampler and the sampling angle are important factors which affect sampling, but if the sampling width is narrow enough, the influence of the sampling angle on the distributions and fibrogram is small enough to be omitted. This is an important conclusion for sampling, in light of this, some suggestions for designing new type sampler are put forward.

  9. About Viscosity of Cotton Fiber

    Institute of Scientific and Technical Information of China (English)

    SAGDULLAEV Ahror

    2008-01-01

    @@ The biological variety is mainly connected with presence of the field ecosites,which determine the mechanism of interaction (the symbiosis,pathogenesis,and etc.) that differ typically of such niches of live organism.The biological,forming on sowing of the cultural plants,including cotton plant are the example for this.Their formation is conditioned presence of the separations of aphids,consisting of different sugar,squirrel,ferment,pigment and other component natural substrata.Simultaneously with creation of in natural,it begins shaping the system with determined by balance insect and successes of microorganism.

  10. Trichoderma rot on ‘Fallglo’ Tangerine Fruit

    Science.gov (United States)

    In September 2009, brown rot symptoms were observed on ‘Fallglo’ fruit after 7 weeks of storage. Fourteen days prior to harvest, fruit were treated by dipping into one of four different fungicide solutions. Control fruit were dipped in tap water. After harvest, the fruit were degreened with 5 ppm et...

  11. Advancing our understanding of charcoal rot in soybeans

    Science.gov (United States)

    Charcoal rot (Macrophomina phaseolina (Tassi) Goid ) of soybean [Glycine max (L.) Merr.], is an important but commonly misidentified disease, and very few summary articles exist on this pathosystem. Research conducted over the last 10 years has improved our understanding of the environment conducive...

  12. Evaluation of common bean (Phaseolus vulgaris) response to charcoal rot

    Science.gov (United States)

    Charcoal rot in common beans (Phaseolus vulgaris L.), caused by Macrophomina phaseolina (Tassi) Gold. (Mph), is an endemic disease in the prevailing hot and dry conditions in southern Puerto Rico. This study evaluated the 120 bean genotypes that compose the BASE 120 panel under screenhouse conditio...

  13. Antibacterial activity of plant defensins against alfalfa crown rot pathogens

    Science.gov (United States)

    Alfalfa (Medicago sativa) is the fourth most widely grown crop in the United States. Alfalfa crown rot is a disease complex that severely decreases alfalfa stand density and productivity in all alfalfa-producing areas. Currently, there are no viable methods of disease control. Plant defensins are sm...

  14. Rice Sheath Rot: An Emerging Ubiquitous Destructive Disease Complex.

    Science.gov (United States)

    Bigirimana, Vincent de P; Hua, Gia K H; Nyamangyoku, Obedi I; Höfte, Monica

    2015-01-01

    Around one century ago, a rice disease characterized mainly by rotting of sheaths was reported in Taiwan. The causal agent was identified as Acrocylindrium oryzae, later known as Sarocladium oryzae. Since then it has become clear that various other organisms can cause similar disease symptoms, including Fusarium sp. and fluorescent pseudomonads. These organisms have in common that they produce a range of phytotoxins that induce necrosis in plants. The same agents also cause grain discoloration, chaffiness, and sterility and are all seed-transmitted. Rice sheath rot disease symptoms are found in all rice-growing areas of the world. The disease is now getting momentum and is considered as an important emerging rice production threat. The disease can lead to variable yield losses, which can be as high as 85%. This review aims at improving our understanding of the disease etiology of rice sheath rot and mainly deals with the three most reported rice sheath rot pathogens: S. oryzae, the Fusarium fujikuroi complex, and Pseudomonas fuscovaginae. Causal agents, pathogenicity determinants, interactions among the various pathogens, epidemiology, geographical distribution, and control options will be discussed.

  15. Reference rot in scholarly statement: threat and remedy

    Directory of Open Access Journals (Sweden)

    Peter Burnhill

    2015-07-01

    Full Text Available As the scholarly communication system evolves to become natively web based, citations now commonly include hyperlinks to content that is issued on the web. The content at the end of those hyperlinks is subject to what has been termed ‘reference rot’: a link may break or the content at the end of the link may no longer represent what was first noted as significant. Reference rot threatens both the usability of what is published and the long-term integrity of the scholarly record. The aim of the Hiberlink project has been to focus on this problem and then to compile and analyse a large corpus of full-text publications in order to quantify the extent of reference rot. The results are now out, and the task has shifted to alerting publishers and libraries on what to do in order to ensure that published web-based references do not rot over time. This has implications for the integrity of the scholarly record and for authors of that record. Fortunately, the Hiberlink project has progressed further than originally envisaged and has recommended remedies aimed at alleviating reference rot.

  16. Production and optimization of ligninolytic enzymes by white rot ...

    African Journals Online (AJOL)

    Production and optimization of ligninolytic enzymes by white rot fungus ... size and nutritional factors (carbon and nitrogen ratio, mediators and metal ions). ... manganese peroxidase (MnP), 2700 IU/ml for lignins peroxidase (LiP) and 345 IU/ml ...

  17. Use of sodium metasilicate for management of peach brown rot

    Directory of Open Access Journals (Sweden)

    Elizandra Pivotto Pavanello

    2016-09-01

    Full Text Available Peach brown rot, caused by the Monilinia fructicola fungus, is the main disease affecting peach crops, and it is mainly controlled via frequent fungicide applications. This study aimed at searching for alternatives to the intensive use of chemicals, evaluating silicon doses to control pre and postharvest peach brown rot and their influence on maturation parameters and fruit quality. Treatments consisted of control (water and sodium metasilicate doses (2 g L-1, 4 g L-1, 6 g L-1, 8 g L-1 and 10 g L-1 of water. The following assessments were made: spore germination and in vitro mycelial growth, brown rot incidence, soluble solids, titratable acidity, flesh firmness, total polyphenol content and fruit ethylene production and respiration rate. The 2 g L-1 dose reduced spore germination by 95 %. Doses of 6 g L-1 and 8 g L-1 satisfactorily reduced the disease incidence in the field, with 77 % and 89.2 % control, respectively. Sodium metasilicate resulted in the maintenance of great fruit firmness, reduced respiration and ethylene production and increased total polyphenol synthesis, but it did not influence the titratable acidity or soluble solids. Applying 6 g L-1 may potentially control pre and postharvest peach brown rot, besides increasing the total polyphenol synthesis and maintaining a higher flesh firmness.

  18. Fusarium stalk blight and rot in sugar beet

    Science.gov (United States)

    Fusarium stalk blight of sugar beet can cause reductions or complete loss of seed production. The causal agent is Fusarium oxysporum. In addition, Fusarium solani has been demonstrated to cause a rot of sugar beet seed stalk, and other species have been reported associated with sugar beet fruit, but...

  19. OXIDATION OF PERSISTANT ENVIRONMENTAL POLLUTANTS BY A WHITE ROT FUNGUS

    Science.gov (United States)

    The white rot fungus Phanerochaete chrysosporium degraded DDT [1,1,-bis(4-chlorophenyl)-2,2,2-trichloroethane], 3,4,3',4'-tetrachlorobiphenyl, 2,4,5,2',-4',5'-hexachlorobiphenyl, 2,3,7,8-tetrachlorodibenzo-p-dioxin, lindane (1,2,3,4,5,6-hexachlorocylohexane), and benzo[a]pyrene t...

  20. Botanicals to Control Soft Rot Bacteria of Potato

    Directory of Open Access Journals (Sweden)

    M. M. Rahman

    2012-01-01

    Full Text Available Extracts from eleven different plant species such as jute (Corchorus capsularis L., cheerota (Swertia chiraita Ham., chatim (Alstonia scholaris L., mander (Erythrina variegata, bael (Aegle marmelos L., marigold (Tagetes erecta, onion (Allium cepa, garlic (Allium sativum L., neem (Azadiracta indica, lime (Citrus aurantifolia, and turmeric (Curcuma longa L. were tested for antibacterial activity against potato soft rot bacteria, E. carotovora subsp. carotovora (Ecc P-138, under in vitro and storage conditions. Previously, Ecc P-138 was identified as the most aggressive soft rot bacterium in Bangladeshi potatoes. Of the 11 different plant extracts, only extracts from dried jute leaves and cheerota significantly inhibited growth of Ecc P-138 in vitro. Finally, both plant extracts were tested to control the soft rot disease of potato tuber under storage conditions. In a 22-week storage condition, the treated potatoes were significantly more protected against the soft rot infection than those of untreated samples in terms of infection rate and weight loss. The jute leaf extracts showed more pronounced inhibitory effects on Ecc-138 growth both in in vitro and storage experiments.