Genetic analysis of adaptive and physiological traits in response to high temperature stress in rapeseed (Brassica napus L.)

A study was conducted to find out the genetic variation for physiological traits in response to high temperature in diverse crosses between yellow sarson (B9, YSH401 and NRCYS05-03) and toria ( Jeuti and TS06) of Brassica napus L. screened under temperature gradient tunnel. Significant variation was observed for all traits in high temperature stress environment. Parents, Jeuti and TS46 along with the crosses B9 x Jeuti, YSH401 x TS46, NRCYS05-03 x Jeuti and NRCYS05-03 x TS46 were found promising based on mean performance for yield attributing characters under stress conditions. YSH401 was a good general combiner for heat susceptibility index and B9 x YSH401, B9 x TS46 and YSH401 x Jeuti were observed as heat tolerant. Main shoot length, number of flowers on main shoot, number of siliquae on the main shoot, siliqua density, per cent flower drop, number of siliquae on a terminal shoot, biological yield per plant and seed yield per plant showed high genetic variation with high heritability and genetic advance. The number of flowers on main shoot was positively correlated with siliquae on the main shoot and seed yield per plant.