Correlação entre caracteres e estimação de parâmetros populacionais para batata-doce

Abstract

Sweetpotato cultivars currently grown were selected essentially for their use in human consumption, with little regard for their other potential uses such as ethanol production or animal feed. The objective of this work was to estimate population parameters and genotypic, phenotypic and environmental correlations associated with these traits. Thirty-nine sweetpotato genotypes from the germplasm bank of the Universidade Federal de Lavras were assayed in a randomized complete block design trial with 2 replications. The estimated genetic (CVg) and environmental (CVe) coefficients of variation, the broad sense heritabilities (ha2) and the b= CVg/CVe ratio favor selection of the majority of the traits analysed, with estimates generally higher than 9.52%, 1.44 and 79.31% for CVg, CVg/CVe and ha2, respectively. For all pairs of traits studied, the genotypic and phenotypic correlations had the same sign, and were similar in both magnitude and level of significance. In the cases where correlations were significant, the estimates of the genotypic correlations were slightly higher than those of the phenotypic correlations, and both were higher than environmental correlations as was observed between total fresh root yield x percentage of dry matter in roots, percentage of dry matter in the leaves+vines x total fresh root yield, mean root shape ratings x general root shape ratings. No genetic or phenotypic correlation was observed beetween percentage of root dry matter and measured root density. The selection and recommendation of sweet potato genotypes based on a set of these studied characteristics (depending on the segment of market to be explored), will make possible the complete use of this precious vegetable genetic resource, and its more intense adoption in national agriculture.