Genetic structure change of selection cycles for reduced ASI of an Algerian maize population under drought conditions

Abstract

Plant breeding involves a reduction of genetic diversity that could hinder the expected response to further selection, and the magnitude of that detrimental effect depends on both breeding population and breeding program design. The objective of the current study was to evaluate the effect of selection for reduced anthesis-silking interval in an Algerian maize (Zea mays L.) population in order to assess the potential value of this population and breeding strategy for subsequent breeding programs. We genotyped Cycle 0 and Cycle 3 from selection for reduced anthesis-silking interval under drought conditions of the Algerian maize population LOM, which was the best performing population in a previous breeding program, with 34 polymorphic simple sequence repeat markers. These selected markers were highly informative with Polymorphism Information Content values = 0.72 and genetic diversity was maintained over the selection cycles. The genetic distance (Nei’s, 1978) between the two cycles was 0.47 and the genetic identity was 0.62. These results indicate that the population LOM was highly variable and that the genetic diversity was not significantly reduced for most genetic parameters by this selection program for reduced anthesis-silking interval. However, genetic selection has caused several genetic changes in Cycle 3 respect to Cycle 0, generating a large genetic divergence between the two cycles of selection. Variations in allelic frequency suggest that further studies could reveal markers associated with selection that could be useful for identifying quantitative trait loci