Resistance evaluation and yield loss of peanut lines to peanut stem rot caused by Sclerotium rolfsii.

Ten peanut lines developed by Oil Crops Research Institute (CAAS, Wuhan, China) were evaluated for resistance and yield loss to peanut stem rot caused by Sclerotium rolfsii under natural disease condition and by artificial inoculation. Results indicated that the wilting rates of these lines ranged from 11.0% to 50.0% under natural disease condition and 7 lines had the wilting rates lower than 30. 0%. Peanut yield and wilting rate were significantly negative correlated (r= -0.73,P < 0.05). The wilting rates of these lines (from 66.1% to 94.0%), at two weeks post inoculation in the artificial inoculation experiment,were lower than those (from 66.1% to 97.4%) before harvest, all these lines were susceptible to infection by S. rolfsii. The peanut yield was negatively related with wilting rate by artificial inoculation with the correlation coefficient of -0.85 (P <0.05). The peanut yield loss was higher than 91.7% for all these lines after artificial inoculation. One tolerant line 16 - A13440 was identified. [ABSTRACT FROM AUTHOR]