Divergence and genetic parameters between coffea sp. genotypes based in foliar morpho-anatomical traits

Abstract

Knowing the genetic variability of a population is essential for guiding its preservation and maintenance, in addition to increasing the efficiency of genetic breeding programs. On this basis, the objective of this work was to estimate the genetic parameters, and to study genetic divergence in a coffee plants population constituted by 30 genotypes of Coffea canephora and 4 of C. arabica, by means of univariate and multivariate statistical procedures based on easy to obtain leaf morpho-anatomic characteristics (stomata number; index, density, area index, polar diameter, equatorial diameter, and functionality, as well as leaf area, dry weight, and specific dry weight). The materials were arranged in a randomized-blocks experimental design with four replicates. Significant differences were detected by the F-test (p < 0.01) between genotypes of Coffea sp. and for all morphological characters evaluated. This highlighted the heterogeneity of the genetic constitution of the evaluated population, which is quite relevant for the genetic divergence analysis and for breeding purposes, having the potential to identify superior genotypes. The tests of Scott-Knott allowed to detect variability between genotypes for all evaluated leaf morpho-anatomical characteristics, distributing genotypes in up to five groups. The clusters formed by Tocher’s optimization and the UPGMA hierarchical method were concordant, grouping the genotypes in ten and seven groups, respectively, showing similarities in the clusters. Three of the four clustered genotypes of C. arabica constituted an exclusive group for this species, in both methods. The characteristics with higher contribution to such distribution were stomata density (37.1%), number (17.3%), and index (12.1%), which together were responsible for 66.5% of the genetic diversity between the studied genotypes.