Heritability and genotypic correlation between plant height andnumber of branches during the initial growth of <em>Stylosanthesguianensis</em> ¹

Abstract

This research determined the heritability and the genotypic correlation between plant height and number of branches of 6 Stylosanthes guianensis (Aubl.) Sw. accessions, whose seeds were obtained from the "Banco Ativo de Germoplasma Forrageiro, EMBRAPA Cerrados". The following genetic parameters were estimated: heritability (h²m), coefficient of genetic variation (CVg), coefficient of environmental variation (CVe) and genotypic correlations between the two traits, during different stages of the initial growth of S. guianensis. The experiment was carried out in a randomized block design with four repetitions, consisting of five plants per repetition. The results showed that there is high genetic variability among the accessions under observation, indicating that a selection program with the most efficient materials would lead to genetic improvements. Plant height shows high genotypic correlation in the different growing stages. It is an indication that it is possible to have the same gene pool, which determines the manifestation of plant height over time, and that the selection should be carried out in the earlier growing stages. The genotypic correlation between plant height and number of branches is of low magnitude. This suggests that, at least, some of the genes involved in these traits are, probably, independent. In this case, the selection of one of these growth traits does not necessarily improve the other one. Additional keywords: forage legume, genetics improvement, genetic parameters.