Phenotypic diversity and relationships between morphological traits in selected almond (Prunus amygdalus) germplasm

Abstract

Almond production in Iran occupies an important place in worldwide production and is of considerable importance in terms of providing genetic resources. In this study, 90 almond genotypes were evaluated using 60 morphological and agronomic characters. Results reflected a significant diversity in the assayed almond germplasm. All traits showed large differences between the studied almonds especially the nut and kernel dimensions, weight, flowering and ripening dates, kernel yield and percentage of double kernels. Furthermore, most of the agronomic traits were correlated, although the correlation coefficients were higher than 0.50 only in some cases. Morphological traits were categorized by principal components analysis (PCA) into 17 components which explained 77 % of the total variation. An unweighted pair-group method of arithmetic average dendrogram and a scatter plot of PCA scores showed high variation between almond genotypes, indicating that the studied germplasm can be considered a good gene pool for breeding programs. Some genotypes could be good genitors for increasing kernel size or can be considered unique, promising types for breeding or commercial growing. Also, some were late-flowering, and so can be used in breeding for later flowering.