Sheath blight is one of the most important and intractable diseases of rice oryza sativa where limited control has been achieved using traditional approaches. The battles are those of disruption, restoration of signaling and information transmission on a subcellular level. Rhizoctonia solani kuhn sheath blight has been the most economically significant disease of rice in louisiana since the early 1970s. Rice sheath blight disease resistance identified in oryza spp. Major gene, nonallelic sheath blight resistance from the. Characterization of quantitative trait loci qtls in.
Sheath blight caused by soil borne necrotrophic fungus rhizoctonia solani teleomorphthanatephorus cucumeris frank donk. Furthermore, according to lee and rush 1983, the yield lost reach up to 50% with symptoms spread to the sheath and leaves of rice plants. Rice sheath blight is one of the most economically significant rice diseases worldwide. Sheath blight of rice caused by rhizoctonia solani kuhn is an important soilborne disease throughout the riceproducing areas of the world. Lesions girdling upper leaf sheath of rice plant at early heading growth stage. Enhanced resistance to rice blast and sheath blight in. Nov 18, 2010 sheath blight shb disease, caused by rhizoctonia solani, is an economically important rice disease worldwide, especially in intensive production systems. Enhanced resistance to rice blast and sheath blight in rice. Jarrod hardkes projection, over 90% of arkansas rice in 2018 will reach.
Fungicidal management of shb often gives inconsistent results and is not economical. Datta2 and karabi datta2 1icarnational rice research institute, cuttack, india 2laboratory of translational research on transgenic crops, department of botany, university of calcutta, kolkata. Diagnosis of common diseases of rice home irri rice. In this study, we determined that rhizoctonia solani infection significantly induced lpa1 expression in the leaves, and. Thanatephorus cucumeris frank donk is of worldwide. Farmers in bangladesh now have ways to lessen the damage that sheath blight can do to their rice crops. 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 has been the most economically significant disease of rice in louisiana since the early 1970s. Loose plant architecture 1 lpa1, an indeterminate domain idd protein, exhibits almost no expression in the leaves, but the overexpression of lpa1 significantly increases the resistance of rice to sheath blight disease shb via the activation of pinformed 1a pin1a. Field efficacy of fungicides for management of sheath. Biological control of sheath blight of rice with bacterial and. To date, none of the genotypes screened are immune to shb, although variation in levels of.
Ou, 19873 has become an important disease of rice, especially in intensive production systems otomo, 1989. The disease is caused by a soil living basidiomycote fungal pathogen, rhizoctonia solani kuhn. 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. Sensitivity to a phytotoxin from rhizoctonia solani. Microorganisms free fulltext yeast associated with rice. The disease is increasing over the year in india and cause up to 69% yield loss under favourable conditions. The pathogen is challenging to manage because of its extensively broad host range and high genetic variability and also due to the. High nitrogen rates and plant density provide favorable microclimate conditions for the development of sheath blight during early heading and grainfilling stages. Epidemics of sheath blight occur throughout the temperate and tropical rice growing regions. Sheath blight is a fungal disease caused by rhizoctonia solani. Pdf sheath blight of rice caused by rhizoctonia solani kuhn teleomorph. A modest estimation of losses due to sheath blight disease alone in india has been up to 54. Efficacy of fungicides for the management of sheath blight. First observations were recorded after 1520 days of inoculation of sheath blight pathogen, second observations were recorded at the flowering stage.
Rice sheath blight disease causes yield losses of 25%35% of thai rice production 10. Sheath blight shb is a soilborne disease causing major economic losses to rice cultivation. However, previous research indicated that lpa1 was expressed at very low levels in the leaves and sheath wu et al. Previously we demonstrated that the overexpression of lpa1 significantly promotes the resistance of rice to shb via the activation of pin1a sun et al. To characterize the genetic basis for shb resistance in rice, we conducted association studies for traits related to shb resistance, namely culm length cl, lesion. Development of genetic and molecular tool boxes to control. Management of rice sheath blight and blast in arkansas. Summary 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 highyielding. It can reach to damaging levels in most long term rice fields growing highly susceptible semidwarf long grain rice varieties. Identification of promising resistance sources against sheath.
Thanatephorus cucumeris frank donk is of worldwide occurrence and is known to cause substantial yield losses. Rice sheath blight disease is the main diseases in rice cultivation which reported in 1910 lee and rush, 1983. Management of sheath blight and enhancement of growth and. Photos of rice sheath blight disease caused by the fungus rhizoctonia solani, including fungal signs and symptoms on the plant. Molla1,2,3,4, subhasis karmakar2, johiruddin molla5, prasad bajaj5, rajeev k.
Identification of promising resistance sources against sheath blight from the annual wild species of rice oryza nivara sharma et shastry volume 17 issue 6 s. These yeast strains were evaluated for controlling rice sheath blight caused by r. Based on the sheath blight severity the test lines were categorized into different categories of resistance and susceptibility. It is a rice disease caused by the soilborne fungus rhizoctonia solani. Kumar ccs haryana agricultural university, rice research station, kaul. Severe infection from heading to milking and dough stages resulting in sterile spikelets and unfilled grains, and lodging. Sheath blight or nbls incidence or fungicide treatments did not significantly affect rice milling yields.
The organism causing sheath blight also causes diseases on rotation crops including soybeans and corn. Epidemics of sheath blight occur throughout the temperate and tropical ricegrowing regions. Indeterminate domain proteins regulate rice defense to sheath. The disease is caused by r hizoctonia solani kuhn known as fungal pathogen. Sheath blight is considered to be an important disease next to rice blast. Jan 14, 2016 solani is a soilborne pathogen having a broad host range including rice and soybean. This disease is the second most important rice disease worldwide 11. Field efficacy of fungicides for management of sheath blight. Frdm the epidemiological viewpoint, rice sheath blight i 359. Sheath blight of rice caused by rhizoctonia solani kuhn teleomorph. Pdf biocontrol of rice sheath blight with formulated. Spraying of infected plants with fungicides, such as benomyl and iprodione, and antibiotics, such as validamycin and polyoxin, is effective against the disease. Efficacy of fungicides for the management of sheath blight of. However, there is much variation in quantitatively inherited resistance to r.
Sheath blight of rice caused by rhizoctonia solani kuhn is a serious threat in rice growing areas. Crop protection tamil nadu agricultural university. Sheath blight is one of the most important and intractable diseases of rice oryza sativa where limited control has. Sheath blight, caused by rhizoctonia solani, is one of the most important diseases of rice. Perpetuation of rice sheath blight pathogen thanatephorus. Rice sheath blight complex caused by rhizoctonia species. The pathogen is challenging to manage because of its extensively broad host range and high genetic variability and also due to the inability to find any satisfactory level of. The genetic arms race between pathogen and host plant is a tug of war that has been ongoing for millennia. New fungicide for sheath blight on rice english, pdf. One such battle occurs between rice an important crop that feeds 50% of the world population and the sheath blight disease sb caused by the fungus rhizoctonia solani.
Rice sheath blight is an increasing concern for rice production especially in intensified production systems. The key obstacle in achieving optimal yields is the occurrence of rice diseases about 70 caused by fungi, bacteria, viruses, and nematodes. Rice is an important food grain and is a staple food for majority of the worlds population. Rice sheath disease has been one of the major constraints for stable rice production in the southern usa and worldwide. Dec 18, 2019 sheath blight shb, caused by rhizoctonia solani kuhn, is one of the most destructive rice diseases.
Major gene, nonallelic sheath blight resistance from the rice. Rice sheath blight disease resistance identified in. The management of rice diseases caused by fungi is mainly based on the use of the chemical. Integrated management of sheath blight of rice by fertilizers. Sheath blight shb of rice caused by rhizoctonia solani, causes significant yield losses worldwide. This disease causes significant grain yield and quality losses. It is a major production constraint in high yielding varieties under. Severe infection results in grain yield loss by as much as 50%. Loss of premature stop codon in the wallassociated kinase 91. Indeterminate domain proteins regulate rice defense to. Management of sheath blight and enhancement of growth.
This suggests that major genes conferring high levels of partial resistance to sheath blight may be incorporated together into lines to give near complete resistance. Reliable and effective disease management strategies are needed for managing rice shb disease. Identification of promising resistance sources against. Control of sheath blight has been mainly through the use of foliar fungicides. Resistance to rice sheath blight rhizoctonia solani kuhn. Review understanding sheath blight resistance in rice. Genomewide association analysis of the genetic basis for. Sheath blight is a serious disease and difficult to detect. Therefore, they have potential for being developed to be used as biocontrol agents for rice sheath blight. Several factors have contributed to the development of sheath blight from minor to major disease status.
Metabolomic study on the resistance mechanism of rice. Here we report the draft genome sequence of the rice sheath blight disease pathogen, r. The disease is caused by rhizoctonia solani, a fungal pathogen of both rice and soybeans. Rice sheath blight disease resistance identified in oryza.
Isolation of fungus from sheath blight diseased sample the isolation of fungus was done from rice plants table 1 showing sheath blight symptoms taheri et al. Sheath blight disease has been causing more crop losses since the deployment of semidwarf rice. Rice sheath blight disease is a major production constraint in punjab, haryana, eastern up, bihar, west bengal, orissa, assam. Rice disease identification photo link lsu agcenter. For sheath blight inoculation, whole plant inoculation assay was used to evaluate the resistance of the transgenic rice against sheath blight disease. Similarly, when the effects of sheath blight on physical properties of rice cultivars cocodrie, cypress, drew and lagrue were tested by candole et al. Several studies have been conducted to identify sources for shb resistance in different species of rice, including local accessions and landraces. In japan, the disease has caused a yield loss of as high as 20% and affected about 120,000. The development of an effective formulation for the biological control agent of sheath blight rhizoctonia solani of rice, p. Exploiting endophytic bacteria for the management of.
The most serious diseases caused by fungal infection are rice blast magnaporthe oryzae, sheath blight rhizoctonia solani and bacterial leaf blight xanthomonas oryzae pv. However, biotic stresses such as diseases have impeded rice cultivation both in the tropics and subtropics. The evolution and pathogenic mechanisms of the rice sheath. The initial lesions are small, ellipsoid or ovoid, and greenishgray photo. Strong sources of genetic resistance are not available for shb, and the disease is currently managed through use of chemical fungicides. This work aimed to study yeasts in the phylloplane of rice, to evaluate the antagonistic activities and mechanisms against rice pathogenic fungi of the rice phylloplane yeasts and to evaluate the e cacy of the selected antagonistic yeasts for controlling the rice sheath blight disease in rice plants in a greenhouse. Samples of rice sheaths were thoroughly washed with running tap water, surface sterilized using 1. Biological control activities of riceassociated bacillus sp. Developing shbresistant rice cultivars represents the most economical and environmentally sound strategy for managing shb. Drastic yield reduction and severe lodging caused by rice sheath blight. Of the various combinations tested, methyl cellulose. Combating rice sheath blight in bangladesh riu validated rnrrs output.
Rhizoctonia solani is a major fungal pathogen of rice oryza sativa l. Symptoms the lesions are usually observed on the leaf sheaths although leaf blades may also be affected. Fungicides to control sheath blight should be applied when effective scouting indicates more than 35% positive stops in susceptible to very susceptible varieties or more than 50%. Rhizoctonia solani, rice, sheath blight history and geographical distribution runner hyphae, ultimately causing death of whole leaf, tiller and the plant. Biological control activities of riceassociated bacillus. Twentynine bacterial endophytes were isolated from different plant sources and tested for their efficacy against r. Frac disease fungicide active ingredient code rateacre comments.
May, 2019 the genetic arms race between pathogen and host plant is a tug of war that has been ongoing for millennia. Jan 27, 2012 photos of rice sheath blight disease caused by the fungus rhizoctonia solani, including fungal signs and symptoms on the plant. Yeast associated with rice phylloplane and their contribution. This makes the identification of major genes for partial resistance to sheath blight critically important to rice breeding programs.
A major rice disease find, read and cite all the research you need on. Lpa1 is induced by rhizoctonia solani, and lpa1 is more susceptible to sheath blight disease. The studies conducted on mode of perpetuation of sheath blight pathogen thanatephorus cucumeris of rice oryza sativa l. Location of the rice sheath blight disease complex survey sites indicated as red triangles in bangladesh during 200103.
The sheath blight fungus is soilborne and has hundreds of hosts including soybean and corn. 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. Strobilurin fungicides have been used extensively to manage these two diseases, especially sheath blight. Carbendazim 1 glit, propiconazole 1mllit may be applied. Sensitivity to a phytotoxin from rhizoctonia solani correlates with sheath blight susceptibility in rice. Sheath blight caused by rhizoctonia solani ag1ia and narrow brown leaf spot nbls, caused by cercospora janseana are among the most important diseases affecting rice production in texas and in other regions in the southern united states. Efficacy of new combination fungicide against rice sheath. Yield losses of up to 50% have been reported under most conducive environments. 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. The genome encodes a large and diverse set of secreted proteins. Fungicides for sheath blight are recommended if the disease level reaches its threshold level. Despite extensive searches of the rice germ plasm, the major genes which give complete resistance to the fungus have not been identified. Loss of premature stop codon in the wallassociated kinase.
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