Dissimilaridade genética de soja a partir de descritores morfológicos na fase vegetativa

Abstract

The genetic base of Brazilian soybeans is narrow, so its genetic diversity is useful to assist in the selection of parents. This study aimed to evaluate and determine phenotypic variability and genetic diversity in 55 soybean genotypes based on vegetative phase traits. 52 progenies and 3 cultivars (BRS 7380 RR; TMG 1179 RR; BMX Desafio RR) were evaluated in a randomized block experimental design with 3 replications. Sowing took place in October in the 2022/2023 harvest, and the characters of hypocotyl length (CH), epicotyl length (CE), unifoliate leaf petiole length (CPFU), greatest left lateral distance (DLE), greatest right lateral distance (DLD), distance from the base of the unifoliate leaf (DBFU), petiole length of the first trifoliate leaf (CP1FT), rachis length of the central leaflet of the first trifoliate leaf (R1FT) and length of the first internode (C1IN) . Generalized Mahalanobis distance was obtained, which allowed us to infer that among the characters evaluated, those that presented the greatest relative contribution to genetic divergence. The CE, CPFU and C1IN characters presented the greatest contribution, respectively, with 18.26%, 15.32% and 15.82%. From the groupings carried out by the dendrogram and the tocher grouping, as well as the dissimilarity measures, it was possible to infer that analyzes carried out during the vegetative phase are important in evaluating genotypes and predicting results obtained during the breeding process.