Susceptibility of rice hybrids and inbred cultivars to false smut under field conditions.

摘要

Results are presented of a study conducted during 2011-12 in Ludhiana, Punjab, India, to evaluate 25 hybrids and 10 inbred cultivars of rice for resistance to false smut (caused by Ustilaginoidea virens). Different disease variables such as number of smut balls per panicle and percentage infected spikelets were measured, and visual score on 0-9 scale was calculated as per Standard Evaluation System for rice. Percentage sterility was also determined by counting sterile grain/healthy grain. Days to 50% flowering of each genotype were also recorded. Among the different genotypes, two inbred cultivars, PR113 and PR114, had the lowest level of disease intensity and two hybrids, NPH 369 and NPH 909, consistently had the highest level of disease intensity. The hybrids showed higher level of disease incidence compared to the inbred cultivars. Agrometeorological data (total rainfall, maximum and minimum temperature, and morning and evening relative humidity) were positively correlated with all the disease variables.