Potencial produtivo e divergência genética de progênies de meios-irmãos de milho superdoce e crioulo para consumo in natura

Abstract

The objectives of the study were evaluate the potential of half-sib progenies of supersweet corn and landrace corn aiming to in natura green corn production, estimate the genetic variability and select progenies with high performance that gather the major number of interest traits by the multivariate statistic techniques. The first experiment of supersweet corn was conducted with 85 half-sib progenies plus commercial control Tropical Plus, Sakata HS, Sakata HT, Azteca and Cativerde. The landrace corn experiment was constituted by 98 half-sib progenies and as experimental control the hybrid AG1051 and the variety Cativerde, the trials were evaluatedin a randomized block design with three replications. Were analyzed in both experiments 10 phenotypic variables related to agronomic adaptation and ear yield potential. Were estimated the genetic parameters, inheritance and expected selection gain. The genetic divergence between the corn genotypes was obtained from the General Square Distance of Mahalanobis, being the genotypes grouping by genetic dissimilarity through the UPGMA and Tocher Optimization methods. Additionally, the phenotypic variables were submitted to principal component analysis for reduction the data dimension. The results showed both to the supersweet corn and landrace corn populations, high genetic variability enabling possible genetic gains with the artificial selection, high potential for ear yield and ear quality for in naturaconsumption when compared to the commercial control. The UPGMA grouping was more sensitive in separate the genotypes in seven and 10 groups for supersweet and landrace corn, respectively. The principal component analysis (PCA) reduce the set of variable were the three first components explained 71.67% (supersweet) and 63.99% (landrace)of the phenotypic variance, being that in the two populations the ear yield variable was the most influential eigenvectorin the formation of the PC1 and PC2. For the genetic divergence study between the corn genotypes (supersweet and landrace) the variables linked to productive potential were again the most important. From the principal component analysis was possible the selection of 27 half-sib progenies of supersweet corn and 30 half-sib progenies of landrace corn and performed the estimate of genetic gains with artificial selection. The observed results for the both corn populations (supersweet and landrace) highlighting the existence of genetic variability favorable between the half-sib corn progenies for aptitude to green cornin natura production.