Genetic improvement of Stylosanthes guianensis populations

Abstract

This research was carried out to obtain information about the adequate number of populations, replications, and plants per lot, to be adopted in genetic improvement programs for Stylosanthes guianensis, and to obtain the genetic and phenotypic correlations between the characters mean diameter, basal area, growth habit, foliage, green weight and dry weight. It was observed that more precise means were obtained in large experiments. The experimental precision was influenced mainly by the number of populations and number of replications, and the influence of number of plants per plot was minor. All phenotypic correlations within plots, involving mean diameter, basal area, green weight and dry weight were significant and positive. The genetic correlations were significant and positive for 10 out of 15 combinations among the six characteres analysed. Therefore, dry weight can be indirectly increased through selection for large diameter, basal area and green weight.