Combined selection and multivariate analysis in early generations of intraspecific progenies of peanuts

摘要

Selection indexes are useful tools for the simultaneous selection of several descriptors aiming to promote genetic gains and a reliable advancement of segregating populations. This study tested the use of selection index of distance from the genotype to the ideotype to assist in the search for superior progenies, based on agronomic variables obtained from early generation progeny of intraspecific progenies of peanuts ( Arachis hypogaea L.) Four segregating populations were used, each consisting of 90 progenies, arranged in a randomized block design with three replicates, in which the best 30 progenies of each population were selected. The index of distance to the ideotype, used for the selection, was built from a non-real model cultivar that meets the requirements for traits main stem height (SH), early flowering (EF), number of pegs (NP), number of pods per plant (NPP), weight of 100 pods (WP100), number of seeds per plant, and weight 100 seed (WS100). It was observed that the selection index used was effective for differentiating progenies and promoting gains at a selection pressure of 33.33%. Gains were variable for the same traits in the different populations. The number of pods per plant, for example, ranged from 3.96% in the population 3 to 16.98% in the population 4. The analysis of diversity showed that progenies selected grouped differently, by principal coordinates analysis, which corroborates the ability of the index to form groups according to traits of interest. The groups formed revealed moderate variability by the diversity analysis by the Ward/MLM method.