Partial circulant diallel cross at the interpopulation level in the identification of elite lines and prediction of maize hybrids

Abstract

The Partial Circulant Diallel Cross at the Interpopulation Level (PCDCI) was proposed with the aim of better exploiting heterosis, by combining lines of different heterotic groups, and allowing the assessment of the combinatorial potential of a greater number of lines (n) which participate in s crosses, with a reduced number of evaluated hybrid combinations (ns), to estimate [n(n-s)] non-evaluated hybrids. The objectives of this study were to determine the potential of PCDCI to identify elite lines and superior combinations among the evaluated hybrids and to predict the performance of non-evaluated hybrids using a reduced model. Four PCDCI diallels were obtained involving six synthetics of maize, using groups of 20 S₅ lines per synthetic. Each line was combined with four lines of the contrasting group (s=4), in each diallel, resulting in 80 hybrid combinations per diallel, which were used to predict the performance of 320 other non-evaluated combinations. The 80 hybrid combinations and four commercial controls were evaluated for grain yield using a randomized block design with two replications, in two crops. Individual and combined analyses of variance were performed based on treatment means, with diallel analyses performed and genetic parameter effects estimated using the ordinary least squares method. The significant effects of general and specific combining ability and their interactions with the crops show that both additive and dominance effects were important for yield. The means of hybrids as estimated by the reduced models were highly correlated with the observed means, with correlation coefficients between 0.75 and 0.93. The use of PCDCI is efficient for predicting the hybrids not evaluated in the diallels and allows identifying elite lines for the production of hybrids.