Variability of red clover genotypes on the basis of morphological markers

Abstract

Red clover (Trifolium pratense L.) is an important forage legume of temperate regions dominantly used as a source of animal food. The present research aimed at assessment of genetic diversity based on morphological markers, through the analyses of five morphological markers in a collection of 46 red clover genotypes. These morphological markers were screened according to the UPOV descriptor (2001) in the trial laid out in a randomized complete block design with three replications. The traits analyzed and investigated were: time of flowering, growth habit, density of hairs, leaf color and intensity of white marks. The average value of Shannon's diversity index for five morphological markers amounted 0.711. Homogeneity analysis (HOMALS) of the same five descriptors accounted for 71.2% of the total variation of the standardized data, with the first and second axis explaining 38.4% and 32.8% of the morphological variability, respectively. Based on this analyses all red clover genotypes were grouped into seven homogeneous groups in two-dimensional space, thus providing visualization of genotypes diversity based on their morphological traits. UPGMA cluster analysis of the same morphological markers allowed the description of four groups with genetic distances represented by the simple matching coefficient of similarity ranging from 0.00 to 1.00. Observed results achieved by these two analyses were compared and although both of analyses were successful in grouping and discrimination of red clover genotypes with some similarities and differences, priority in future breeding programs was given to the HOMALS.