Inheritance of resistance to white rot in cauliflower

Heading broccoli lines EC 131592, Janavon, EC 103576, Kn-81 and Early Winter Adam's White Head were identified as sources of resistance to Sclerotinia sclerotiorum. The resistance was polygenically controlled and recessive in nature. All the crosses showed epistasis gene action but in a cross, it was of complementary nature. In the crosses involving susceptible and resistant parents, additive (d) and additive × dominance (j) gene effects were highly significant but amongst the crosses involving resistant or susceptible parents dominance × dominance (1) component of variance was highly pronounced. Reciprocal recurrent selection will be more useful to take the advantage of additive and non-addictive gene actions at the same time to breed varieties resistant to sclerotinia rot. The cross PSB-I(S) × EC 103576(R) is likely to respond better to selection in the later generations because of complementary type of epistasis including additive variance.