Research article-Development of hybrids resistant to cold and leaf blast in rice (Oryza sativa. L)

The experiment was conducted using 24 parental lines, which included four female
lines crossed with twenty elite, diverse, and proven restorer lines to develop 80
experimental hybrids during the kharif season of 2019. The objective was to screen for cold
and blast resistance during the rabi season of 2019-20, along with susceptible and resistant
checks. Pooled data from cold screening showed that, out of 104 lines, 20 lines exhibited
strong tolerance (ST), 76 lines showed tolerance (T), and 8 lines displayed moderate
tolerance. None of the lines, except the susceptible checks, recorded sensitive or highly
sensitive reactions. Out of 104 entries screened for blast, 73 entries were identified as
resistant (R), 21 lines as moderately resistant (MR), and 10 lines as susceptible. The checks
TN1 was found to be highly susceptible, while US 314 was resistant (IRRI-SES, 2013).
Based on cold and blast scoring data, among the 20 restorer lines, 10 lines showed
tolerance to cold and resistance to leaf blast. Ten restorer lines, namely RNR 26085, ZGY
1, RNR 2354, RNR 28359, RNR 28411, RNR 21571, IR 72, JGL 35126, JGL 35047, and
JGL 34551, were selected and further utilized for combining ability, heterosis, and stability
studies.