An Investigation of Genetic Diversity among Some Almond Genotypes and Species by Morphological Traits

Abstract

Almond [<i>Prunus dulcis</i> (Mill.) D.A. Webb] is one of the species of genus <i>Prunus</i> and subgenus <i>Amygdalus</i> (<i>Rosaceae</i>, subfamily <i>Prunoideae</i>). It is grown commercially worldwide. Iran is one of the main growing areas for commercial and wild almonds due to its suitable climatic conditions. Wild almond species are known to be tolerant to harsh environmental conditions such as drought. They also can be used as rootstock or can be employed in improvement programs. In this study, 62 genotypes including eight different species were evaluated by measuring 15 morphological traits. Correlation coefficient showed significant correlation among length of trunk, diameter of trunk, tree vigor, foliage density, length of main branches, thickness of one year old shoot, leaf length and width, leaf area and the leaf length/width ratio. Principal component analysis showed that length of main branches, ramification, length of one year old shoot, leaf length and width, leaf area and the length/width ratio of leaf had highest loading in the first component that accounted for 35.6% of total variation (67.8%). Cluster analysis divided genotypes into two main groups and wild species were separated at distance of 5 from the others.