Effect of recombination in the maize breeding population with exotic germplasm on the yield stability

Abstract

A little knowledge exists about the probability that recombination in the parental maize populations will enhance the chances to select more stable genotypes. The synthetic parent maize population ((1601/5 x ZPL913)F-2 = R-0) with 25% of exotic germplasm was used to assess: (i) genotype x environment interaction and estimate stability of genotypes using nonparametric statistics; (ii) the effect of three (R-3) and five (R-5) gene recombination cycles on yield stability of genotypes; (iii) relationship among different nonparametric stability measures. The increase of mean grain yield was significant ( lt 0.01) in the R-3 and R-5 in comparison to the R-0, while it was not significant between R-3 and R-5. Analysis of variance showed significant ( lt 0.01) effects of environments, families per set, environment x set interaction, family x environment interaction per set on grain yield. The non-significant noncrossover and significant crossover ( lt 0.01) G x (E) interactions were found according to Bredenkamp procedures and van der Laan-de Kroon test, respectively. The significant ( lt 0.01) differences in stability were observed between R-0-set 3 and R-5-set 3 determined by , R-3-set 1 and R-5-set 1 determined by ( lt 0.05), and R-0-set 3 and R-5-set 3 determined by ( lt 0.05). The significant parameters were those which take into account yield and stability so the differences could be due to differences in yield rather than stability. Findings can help breeders to assume the most optimum number of supplementary gene recombination to achieve satisfactory yield mean and yield stability of maize genotypes originating from breeding populations.