Comportamento genético de progênies de meio-irmãos de pinhão manso no Recôncavo Baiano, Brasil

Abstract

The study aimed at identifying the genetic divergence among populations of Jatropha curcas L. by using multivariate analysis techniques, estimating the coefficients of repeatability and heritability and determining the minimum number of ratings that can provide levels of certainty for the prediction of the actual value of individuals. The traits plant height (PH), stem diameter (AD), primary branching (RP), secondary branching (RS), number of clusters (NC), number of fruits (NF), number of seeds (NS) and number of seeds per fruit (NSF) evaluated in the original population (Po) underwent principal components analysis (PCA) and cluster analysis with the UPGMA method starting from the Euclidian distance matrix. The progeny test was conducted at the Experimental Center of Genetic Improvement and Biotechnology (NBIO), where the coefficients of repeatability of the traits stem diameter, primary branching and survival were estimated. Data underwent variance analysis and the heritability coefficients were estimated through the contribution of MSE. In the study of genetic diversity, the hierarchical clustering using the distance values of Mahalanobis indicated the formation of four groups dissimilarity with higher number of clusters for characters and branching primary. The repeatability coefficient (r) estimated by statistical procedures showed high values (r> 0.90) for the trait survival, with the value of approximately 81%. The number of evaluations needed for an accuracy level of 90% is thirty for the trait plant diameter, twelve for primary branching and two for the trait survival under environmental conditions of the study.