Heterosis and combining ability analysis for seed yield and its attributes in Brassica rapa ssp. brown sarson

Abstract

Combining ability analysis in Brassica rapa ssp. brown sarson revealed significant mean squares for
general and specific combining ability for all the traits studied. The estimates of variance due to dominance
deviation ( D
 2 )were much higher than the corresponding additive genetic variance ( A
 2 ) for all the traits.
The predictability ratio was less than unity for all the traits which indicated that performance on general
combining ability of parents alone would not be advisable to select materials in segregating generations, but a
combination involving both general and specific combining ability of the parents and particular crosses along
with their per se performance would be more useful in selecting materials in the segregating generations.
Heterosis was estimated over mid and better parent, respectively under present study. The most desirable
cross combination CR-1485 x CR-1607 for seed yield plant-1 also showed desirable mid and better parent
heterosis for 1000-seed weight, primary branches plant-1 and seeds siliqua-1. Highest mid and better parent
heterosis showed the cross combinations viz., CR-1485 x CR-1607 (primary branches plant-1), CR-1630 x
KS-101 (secondary branches plant-1), CR-2638 x KOS-1 (siliquae on main shoot),
CR-1630 x CR-2871 (siliquae plant-1), CR-1607 x KOS-1 (days to maturity) and KOS-1 x KS-101
(oil content). These cross combinations also revealed high per se performance.