Assessment of genetic diversity in groundnut (Arachis hypogea L.) germplasm using morphological traits

A field experiment carried out to evaluate genetic diversity in 76 peanut accessions (Arachis hypogea), obtained from National Plant Gene Bank of Iran, in the faculty of Agriculture, the University of Guilan, Rasht, Iran. Eleventh major morphological traits were recorded using ICRISAT Peanut Descriptor during 2002 growing season using a Randomized Complete Block Design (RCBD) with two replications. Application of Pearson correlation indicated that seed length, seed width, pod length and width had a direct positive relation to seed weight (P≤0.01). In addition, the number of pods per plant had a positive correlation with number of seeds per plant and pod weight (P≤0.01). Three components derived from principal component analysis accounted for nearly 72% of whole variability in the evaluated germplasm, defined by number of seeds per plant, pod weight, seed length, seed width, seed weight, number of pods per plant, pod width and pod length. The accessions were divided to three groups by cluster analysis based on Ward method using Squared Euclidian distance coefficient. The studied accessions showed high similarity (0.19), therefore, broadening genetic base of peanut germplasm and use of molecular markers could be suggested in order to complete the morphological traits-based classification and evaluation of genetic diversity in peanut germplasm.