Virulence pattern in Rhizoctonia solani causing sheath blight of Rice

摘要

Rice plants infected with sheath blight collected from different agro climatic zones of India (Table 1). Cut into 1 to 1.5 cm long bits, cleaned in sterilized distilled water and surface sterilized with 2% sodium hypochlorite for 1 min. washed thoroughly three times and were then, placed on PDA in Petri plates and were incubated at 28°C for 3 days. The sterilized typha flask was inoculated with 5 mm diameter disc of actively growing mycelium of the each isolates and incubated for 15 days at 28±2°Cwere used as inocula. Virulence pattern of the all 25 isolates was tested on cv. Pusa Basmati-1 (Pusa 167 x Kamal Local), as it is highly susceptible to sheath blight of rice in glass house. The seedlings of PB-1 were raised in pots, transplanted after25 days of sowing. At the time of maximum tillering, the colonized 2-3 pieces of typha were placed in the centre of plants just above the water level. Relative Lesion Height (RLH) was recorded at two stages, 20 and 35 days after pathogen inoculation.