Exploitation of residual heterosis in F2 for better performance and fruit rot (Colletotrichum capsici(syd.) Butler and Bisby) resistance in chillies (Capsicum annum L.)

Abstract

Selection of parents to produce heterotic Fls and choice of Fls for advancing to obtain heterotic F2s besides adaptability of a parent, F1s and F2s populations for fruit yield and fruit rot resistance. While studying F2 population from a 8x8 diallel, it was observed that the parents IHR 328-9 and IHR 309-3-18 possessed high general combining ability in most environments. F2s of 384 x 328-9, 309-3-18 x 472-12-6-4 exhibited high degree of heterotics. In unfavorable environments additive gene effects and in favorable environments non-additive gene effects were important for yield and its components. The overall means of F1s and F2 s excelled the parental mean in all four environments tested, while means of F1s and F2s were identical in unfavorable environment. Maximum heterotic in F2 was exhibited by 328-9 x 473-11-3-1 in unfavorable and by 328-9 309-3- 18 in favorable environments. Heterotics in F2s was attributed to near complete additivity and accumulation of trangressive segregants. Co-efficient of variation for fruit traits was less than 20%. In the other set of diallels with 5 fruit rot resistant parents and two susceptible, it was found that F1s and F2s of all resistant x resistant were resistant indicating the alleles confirming resistance to be at the same loci. Resistance was shown to be governed by a single recessive gene with modifiers, in all such parents. The F2 hybrids have the advantage of yield and adaptability besides resistance to fruit rot, and the cost of their seed production was comparable with open pollinated varieties.