Sarocladium oryzae

Sarocladium oryzae (Sawada) is a plant pathogen causing the sheath rot disease of rice. In culture it produces 0.3–0.627 micrograms of helvolic acid and 0.9–4.8 micrograms of cerulenin per milliliter of culture medium.[1] The level of helvolic acid correlated with a higher incidence of sheath rot disease. Rice grains from infected plants were found to contain 2.2 micrograms helvolic acid and 1.75 micrograms of cerulein per gram of infected seeds, which induce chlorosis and reduce the seed viability and seedling health.[2] S. oryzae has also been known as Acrocylindrium oryzae (Sawada). For forty years prior to 2005, a common industrial fungal strain used to manufacture cerulenin was known under the invalidly published designation "Cephalosporium caerulens", but an isolate of the original C. caerulens strain KF-140 was subsequently shown to be conspecific with S. oryzae.[3]

Sarocladium oryzae
Scientific classification
Kingdom:
Fungi
Phylum:
Ascomycota
Class:
Ascomycetes
Subclass:
Incertae sedis
Order:
Incertae sedis
Family:
Incertae sedis
Genus:
Sarocladium
Species:
S. oryzae
Binomial name
Sarocladium oryzae
(Sawada) W. Gams & D. Hawksw., (1976)
Synonyms

Acrocylindrium oryzae Sawada, (1922)
Sarocladium attenuatum W. Gams & D. Hawksw., (1976)

The disease is found in rice plants usually injured by insects or other diseases. Hot (20–28 °C (68–82 °F)) and humid (wet) weather favour the growth of the disease. It is also associated with virus-infected plants.[4]

Symptoms

Early symptoms are oblong to irregular spots, with gray centers and brown margins. Spots or rotting occur on the leaf sheath that encloses the young panicles. There is discoloration in the sheath. In severe infection, all or part of the young panicles do not emerge and remain within the sheath. Unemerged panicles will soon rot and produce powdery fungus growth inside the leaf sheath.[4]

Infection occurs on the uppermost leaf sheath at all stages, but is most damaging when it occurs at late booting stage.[4]

Management

Partners of the CABI-led programme, Plantwise including the General Directorate of Agriculture in Cambodia have suggested reducing the density of planted crops to 25 by 25 centimetres (10 in × 10 in) and removing infected stubble and weeds from the field. They also recommend application of fertilisers including potassium, calcium sulphate and zinc sulphate during the tillering stage to strengthen the stem and leaf tissues.[4][5]

The Bureau of Rice Research and Development, Rice Department, of Thailand recommends using disease-free seeds and plants, avoiding monocropping with any one variety of rice (planting at least two varieties in the same field), and regular monitoring of fields.[6]

Sources

 This article incorporates text from a free content work. Licensed under CC-BY-SA License statement/permission on Wikimedia Commons. Text taken from Plantwise Factsheets for Farmers: Rice Sheath Rot -Cambodia, General Directorate of Agriculture (Cambodia), CABI. To learn how to add open license text to Wikipedia articles, please see this how-to page. For information on reusing text from Wikipedia, please see the terms of use.

 This article incorporates text from a free content work. Licensed under CC-BY-SA License statement/permission on Wikimedia Commons. Text taken from PMDG: Rice Sheath Rot - Cambodia, GDA, Phnom Penh, Cambodia, CABI. To learn how to add open license text to Wikipedia articles, please see this how-to page. For information on reusing text from Wikipedia, please see the terms of use.

 This article incorporates text from a free content work. Licensed under CC-BY-SA License statement/permission on Wikimedia Commons. Text taken from PMDG: Dirty Panicle on rice - Thailand, Bureau of rice research and development, Rice Department (Thailand), CABI. To learn how to add open license text to Wikipedia articles, please see this how-to page. For information on reusing text from Wikipedia, please see the terms of use.

References
  1. Ayyadurai N; Kirubakaran SI; Srisha S; Sakthivel N (June 2005). "Biological and molecular variability of Sarocladium oryzae, the sheath rot pathogen of rice (Oryza sativa L.)". Curr. Microbiol. 50 (6): 319–23. doi:10.1007/s00284-005-4509-6. PMID 15968500. S2CID 28559372.
  2. Ghosh MK; Amudha R; Jayachandran S; Sakthivel N (2002). "Detection and quantification of phytotoxic metabolites of Sarocladium oryzae in sheath rot-infected grains of rice". Lett. Appl. Microbiol. 34 (6): 398–401. doi:10.1046/j.1472-765X.2002.01111.x. PMID 12028418. S2CID 25268152.
  3. Bills GF; Platas G; Gams W (November 2004). "Conspecificity of the cerulenin and helvolic acid producing 'Cephalosporium caerulens', and the hypocrealean fungus Sarocladium oryzae". Mycol. Res. 108 (Pt 11): 1291–300. doi:10.1017/S0953756204001297. PMID 15587062.
  4. "Plantwise Knowledge Bank | Rice Sheath Rot". www.plantwise.org. Retrieved 2020-06-10.
  5. "Plantwise Knowledge Bank | Rice Sheath Rot". www.plantwise.org. Retrieved 2020-06-10.
  6. "Plantwise Knowledge Bank | Dirty panicle on rice". www.plantwise.org. Retrieved 2020-06-10.


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