Rice sheath blight is an increasing concern for rice production especially in intensified production systems. Characterization of quantitative trait loci qtls in. Indeterminate domain proteins regulate rice defense to. The accessibility of available tissues to infection is thus limited, and as a result, sheath blight lesions are not randomly distributed over the population of tillers in an infected rice stand. Therefore, they have potential for being developed to be used as biocontrol agents for rice sheath blight. Exploiting endophytic bacteria for the management of sheath blight disease in rice. Compendium of rice diseases and pests, second edition. In japan, the disease has caused a yield loss of as high as 20% and affected about 120,000. Efficacy of fungicides for the management of sheath blight. Sheath blight, caused by rhizoctonia solani, is one of the most important diseases of rice. The disease is increasing over the year in india and cause up to 69% yield loss under favourable conditions. Management of rice sheath blight and blast in arkansas. Sheath blight is considered to be an important disease next to rice blast. Yield loss due to bacterial blight can be as much as 70% when susceptible varieties are grown, in environments favorable to the disease.
Rice sheath blight, one of the major three diseases of rice, is caused by r. Sheath blight is a fungal disease caused by rhizoctonia solani. In case of sheath blight, disease progression and apparent infection rate r were maximum during observation period from 0115 and 1630 october in over the four years kharif season. Field efficacy of fungicides for management of sheath.
Yield losses of up to 50% have been reported under most conducive environments. The rice cyp78a gene bsr2 confers resistance to rhizoctonia. Screening oryza species plants for rice sheath blight. Spraydried powder of bacillus megaterium for control of. This disease causes significant grain yield and quality losses. Sheath blight is one of the most important and intractable diseases of rice oryza sativa where limited control has been achieved using traditional approaches. Sheath blight has been the most important rice disease in arkansas and in the southern united states. Sensitivity to a phytotoxin from rhizoctonia solani correlates with sheath blight susceptibility in rice. This article is a list of diseases of rice oryza sativa. Review understanding sheath blight resistance in rice. The sheath blight fungus is soilborne and has hundreds of hosts including soybean and corn. These yeast strains were evaluated for controlling rice sheath blight caused by r. However, there is much variation in quantitatively inherited resistance to r. Typical sheath blight bird nest damage in a rice field.
In india, total yield loss due to diseases in rice is 35%, in which blast costs 25% loss, sheath blight 20%, blb 10%, tungro and other diseases 45%, rhizoctonia solani was isolated from sheath. Rice sheath blight research should prioritise optimising biological control approaches, identification of resistance gene mechanisms and application in genetic improvement and smart farming for early disease detection. Sensitivity to a phytotoxin from rhizoctonia solani. Drastic yield reduction and severe lodging caused by rice sheath blight. As a result, the leaf area of the canopy can significantly be reduced by the disease. Rice sheath blight the american phytopathological society. Rice sheath blight disease, caused by the basidiomycetous necrotroph rhizoctonia solani, became one of the major threats to the rice cultivation worldwide, especially after the adoption of high.
Sheath blight shb disease, caused by rhizoctonia solani, is an economically important rice disease worldwide, especially in intensive production systems. Diseases of paddy tnau agritech portal crop protection. Reliable and effective disease management strategies are needed for managing rice. Bacterial blight is one of the most serious diseases of rice. Perpetuation of rice sheath blight pathogen thanatephorus. Rice sheath blight is a disease caused by rhizoctonia solani teleomorph is thanetophorus cucumeris, a basidiomycete, that causes a major limitation on rice production in india and other countries of asia, it is also found to be a problem in the southern u. Hence, it is important to increase the yield potential of rice through improving the disease resistance to prevailing rice diseases. It can reach to damaging levels in most long term rice fields growing highly susceptible semidwarf long grain rice varieties.
The compendium of rice diseases and pests, second edition, is a useful tool for academics and professionals involved with rice crops, including researchers, diagnosticians, extension personnel, crop consultants, farm managers, and growers. With free air co 2 enrichment face, rice plants were grown. Biological control activities of rice associated bacillus sp. On the leaf sheath oval or elliptical or irregular greenish grey spots are formed. Disease cycle sheath blight is a modified single cycle disease. Rhizosphereisolated, free living soil bacteria with proven. Strong sources of genetic resistance are not available for shb, and the disease is currently managed through use of chemical fungicides. Pdf sheath blight of rice caused by rhizoctonia solani kuhn teleomorph. Biological control activities of riceassociated bacillus. Management of rice sheath blight and blast in arkansas sheath blight this important disease of rice is very widespread in arkansas and easily found in 5066% of rice fields.
Thanatephorus cucumeris, is a notorious pathogen and has a wide host range with worldwide in di stribution, a very destructive disease under favorable weather conditions in rice growing areas of the world which. Molecular characterization of soil bacteria antagonistic. Groth, 2 nootjarin jungkhun, 3 and jong hyun ham 1. This disease affects rice throughout its life cycle, from the seedling to heading stage, and causes lesions on leaves, sheaths and even panicles. Effect of heterocystous nitrogenfixing cyanobacteria. Pdf exploiting endophytic bacteria for the management of. Sheath blight is present in nearly every arkansas rice field and causes a consistent level of damage each year. Rice sheath blight causes serious damage to rice crops in china. When rice fields were free from diseases both aman and boro gave. Sheath blight resistant and susceptible rice lines in a disease nursery.
Identification of promising resistance sources against. Sheath blight, which is one of the three major diseases of rice, is caused by infection with rhizoctonia solani agi. This created an urgent need for identifying other effective fungicides with different modes of action. The disease is caused by rhizoctonia solani, a fungal pathogen of both rice and soybeans. Effects of elevated atmospheric co2 concentration on the. Arial view of sheath blight damage in a rice field showing windblown distribution of floating inoculum early in the season. Sheath blight of rice caused by rhizoctonia solani teleomorph. Current status of rice breeding for sheath blight resistance.
Genetic engineering of rice for resistance to sheath blight. Rice wild relatives, oryza species, are one possible source of sheath blight rhizoctonia solani resistance genes. Sheath blight caused by soil borne necrotrophic fungus rhizoctonia solani teleomorphthanatephorus cucumeris frank donk. Genetic engineering of crops with plant pathogenesisrelated pr genes may give a promising and longlasting solution for sheath blight disease management. Sheath blight disease shb is one of the three major diseases that are caused by rhizoctonia solani in rice oryza sativa savary et al. Sign up for the nature briefing newsletter what matters in science, free to your inbox daily. Bsr2ox calli but roots failed to form on both regeneration and hormonefree media.
Studies have demonstrated the use of nitrogenfixing cyanobacteria to prevent crop diseases as well as to improve soil fertility and crop productivity. This book on biological control of rice diseases deals with microorganisms and cultural practices as the nonchemical alternatives developed and used to manage devastating rice diseases such as blast, sheath blight, bacterial blight and rice tungro disease in asia. Location of the rice sheath blight disease complex survey sites indicated. Rice sheath blight is an increasing concern for rice production, especially in intensified production systems.
Other crops grown in rotation with rice, including soy. Sheath blight has been the most economically significant disease of rice in louisiana since the early 1970s. Screening oryza species plants for rice sheath blight resistance. The fungus affects the crop from tillering to heading stage. Several studies have been conducted to identify sources for shb resistance in different species of rice, including local accessions and landraces. Rice sheath blight complex caused by rhizoctonia species. Correct diagnosis of sheath blight is important to avoid unnecessary fungicide applications since symptoms of other rice diseases such as aggregate and bordered sheath spots, black sheath spot and stem rot symptoms may be confused with those of the sheath blight. Sheath blight is one of the most important and intractable diseases of rice oryza sativa where limited control has. Bacillus megaterium, biopesticide, formulation, rice disease, spraydried powder introduction rice sheath blight, caused by rhizoctonia solani, is one of the most destructive rice. Inhibition of ossweet11 function in mesophyll cells. We previously reported that sadependent plant immunity contributes to sheath blight resistance in rice and the small model grass species.
Datta2 and karabi datta2 1icarnational rice research institute, cuttack, india 2laboratory of translational research on transgenic crops, department of botany, university of calcutta, kolkata. Sheath blight shb is a soilborne disease causing major economic losses to rice cultivation. Lesions girdling upper leaf sheath of rice plant at early heading growth stage. Sheath blight thanatephorus cucumeris rhizoctonia solani anamorph sheath rot sarocladium oryzae acrocylindrium oryzae. Management of sheath blight and enhancement of growth. New fungicide for sheath blight on rice english, pdf. Several factors have contributed to the development of sheath blight from minor to major disease status. As the spots enlarge, the centre becomes greyish white with an irregular blackish brown or purple brown border.
The value of audpc maximum in first date of sowing followed by second date and least in third date of sowing during kharif 20, 2015, and 2016. Usda is an equal opportunity provider and employer. Rhizoctonia solani, rice, sheath blight history and geographical. The pathogen is challenging to manage because of its extensively broad host range and high genetic variability and also due to the. The earlier the disease occurs, the higher the yield loss. Breeders have always faced challenges in acquiring reliable and absolute resistance to this disease in existing rice germplasm. Rhizoctonia solani, the causal agent of rice sheath blight disease, causes significant. Rice sheath blight, caused by rhizoctonia solani ag11a, is one of the most devasting diseases of the crop.
The disease is caused by a soil living basidiomycote fungal pathogen, rhizoctonia solani kuhn. Microorganisms free fulltext yeast associated with. Strains against sheath blight and bacterial panicle blight of rice bishnu k. A 6year field study was conducted on rice to evaluate the efficacy of newly registered and unregistered fungicides in comparison to common fungicides for management of sheath blight and nbls diseases. The studies conducted on mode of perpetuation of sheath blight pathogen thanatephorus cucumeris of rice oryza sativa l. Molla1,2,3,4, subhasis karmakar2, johiruddin molla5, prasad bajaj5, rajeev k. Sheath blight shb of rice caused by rhizoctonia solani, causes significant yield losses worldwide. To move forward with effective crop protection against sheath blight. The most common practice for rice sheath blight control is still chemical treatment, an environmentally unfriendly way. Benzothiadiazole, a plant defense inducer, negatively. A toolbox for managing blast and sheath blight diseases of rice in. Sheath blight is a soilborne disease caused by the fungus rhizoctonia solani ag1ia. It is a valuable tool for the field, lab, or classroom.
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