Genetic Analysis of Diallel Crosses of Rapeseed (B. rapa) for Screening High Temperature Tolerant Genotypes under Phytotron Facility and Late Field Sown Condition

High temperature tolerance is assuming importance in breeding rapeseed-mustard. In the present investigation attempt was made to study genetic variation for traits in response to high temperature and screened during flowering to pod formation stage. Populations of diallel crosses involving three yellow sarson and two toria varieties were used in this study. The diallel populations were exposed to high temperature at National Phytotron Facility, IARI, New Delhi and also grown in late sown field conditions which generally experience high temperature terminal stress. The temperature treatment was given only to the crosses as the parents did not come to flowering in the normal growth chamber. B9 x Jeuti, B9 x TS46, YSH401 x Jeuti and NRCYS05-03 x Jeuti were found to be promising for yield attributes under phytotron facility. In field experiments, Jeuti, B9 x NRCYS05-03, B9 x YSH401, B9 x Jeuti, NRCYS05-03 x Jeuti, YSH401 x Jeuti and YSH401 x NRCYS05-03 were found promising for seed yield and its attributes. Main shoot length, siliquae on main shoot, seeds per siliqua, percent flower drop, siliqua density and biological yield per plant showed high to moderate heritability with high genetic advance.