Genetic control of efficiency in association of tropical maize with Azospirillum brasilense for grain yield

Abstract This study aims to investigate the genetic control of the efficiency of maize association with Azospirillum brasilense for grain yield. A total of 48 experimental single-cross maize hybrids were evaluated in seven environments for the grain yield without nitrogen topdressing (Nt) and without Azospirillum brasilense (Az), with Nt but without Az, without Nt but with Az, and the efficiency of Azospirillum brasilense itself. The data were used to estimate the variance components and to perform a diallel analysis. The magnitudes of the genotypic determination coefficients indicate that selection is possible for all traits analyzed. Thus, breeding programs should contribute to developing maize genotypes that are more efficient in association with the bacteria. The inbred lines differed regarding the frequency of favorable alleles and contributed differently to the crosses. Therefore, since the Azospirillum brasilense efficiency is under genetic control, it can be improved through selection.