Department of Plant Pathology, CCS, Haryana Agricultural University, Hisar
National Symposium on “Plant Pathology in the Changing Global Scenario” held at National Bureau of Plant Genetic Resources, New Delhi on February 27–28, 2009
Rice (Oryza sativa L.) is one of the foundation crops of India's agriculture. The crop suffers from several diseases including sheath rot caused by Sarocladium oryzae (Sawada) Gams and Hawksworth, which was considered to be a minor disease has now become widely damaging in recent years. The present studies were conducted on severity and frequency of two pathogens (Fusarium moniliforme and Sarocladium oryzae) associated with the commercial rice cultivars in Haryana. The isolations from diseased leaf sheaths of commercial rice varieties viz: Jaya, PR-106, HKR-126, HKR-127, HKRH-1, IR-64, HKR-46 and HKR-47, revealed more frequent association of F. moniliforme with cultivars PR-106 and HKR 126 with 73.3 per cent recovery. Lowest population of this pathogen (13.3%) was associated with cultivar Jaya. Sarocladium oryzae was more frequently isolated from cultivar Jaya and IR-64 with 73.3% and 60.0% recovery, respectively and was least frequent in variety HKR-126 (6.7% recovery). Maximum association of both the pathogens was observed in variety HKR-46. Studies revealed that both the pathogens are associated with the rice but association of theses pathogens varies with the type of the variety. One hundred and twenty three rice genotypes/lines were evaluated for their reaction to Sarocladium oryzae under artificial inoculation conditions. It was revealed that nine genotypes/cultivars viz., HKR98–476 (IET1704), HKR02–430 (IET18995), HKR03–428 (IET19443), HKR04–409; HKR04–479; HKR04–493; HKR05–476; HKR05–497; HKR05–499 showed highly resistant reaction (no disease) against S. oryzae. The genotype HKR05–495 was found resistant (<1% D.I.) and genotypes HKR03–408 (IET19441), HKR04–487; HKR04–523; HKR04–524, HKR05–404 and HKR05–417 were moderately resistant (1–5%D.I.) to the pathogen.
