Selection and genetic dissimilarity in S2 families of guava through seed attributes

Abstract

This study was developed to carry out selection, estimate genetic parameters and predict individual genetic values of 55 genotypes from S 2 families as well as estimate genetic dissimilarity based on physiological seed attributes. All S 2 genotypes evaluated were obtained from self-pollination of S 1 genotypes from the guava breeding program. The experiment was laid out in blocks with 55 S 2 genotypes and four blocks. Genetic parameters were estimated and the best genotypes were selected based on the genetic value, using the statistical method of mixed models. In addition, genetic divergence was estimated based on the mean Euclidean distance. Although heritability values were considered medium to high magnitude for germination (0.22) and germination speed index (0.35), genetic gains were obtained for all traits. Based on the evaluation of individual BLUPs, the S2 genotypes that contributed to most of the evaluated traits were: 5, 31, 85, 214, 369, 393, 398, 442, 443, 444, 449 and 529, suggesting potential to generate vigorous. Through genetic dissimilarity, it was possible to verify the formation of five distinct groups. Therefore, the selection of divergent genotypes with high average for germination is recommended for the advancement of generation in the guava breeding plant.