SALIENT RESEARCH FINDINGS ON VARIABILITY, FUNGICIDAL SENSITIVITY AND PROFILING OF AVR GENES AMONG ISOLATES OF RICE BLAST PATHOGEN ( MAGNAPORTHE ORYZAE )

摘要

Rice blast caused by Magnaporthe oryzae (Herbert) Barr is one of the most economically significant diseases of rice (Silva et al., 2009). The pathogen attacks the crop at all the growth stages and causes huge grain yield losses. Keeping in view the importance of the disease in rice production, the present investigation was carried out to identify the causal organism associated with rice blast in different regions of Telangana and Andhra Pradesh; to study morphological and genetic diversity among rice blast pathogens; profiling of avirulent genes in pathogenic isolates; and evaluating the in vitro sensitivity of M. oryzae isolates to different fungicides. The present research work was carried out at Department of Plant Pathology, College of Agriculture, Professor Jayashankar Telangana State Agricultural University, Rajendranagar and Indian Institute of Rice Research (IIRR), Rajendranagar, Hyderabad. Khammam, Warangal, Nalgonda, Mahbubnagar, Medak, Adilabad, Rangareddy, Nizamabad districts of Telangana and Guntur, Kurnool, Nellore, West Godavari, Srikakulam districts of Andhra Pradesh were selected for collecting the foliar disease samples from rice blast affected fields. The M. oryzae cultures were isolated and purified on Oat Meal Agar medium (OMA) by adopting single spore isolation method. The single spore cultures were maintained on OMA medium, preserved on filter paper discs and stored at 4°C temperature.