Knowledge of the genetic diversity and structure of tree species across their geographical ranges is essen-tial for sustainable use and management. Prunus scoparia (Spach) is a wild almond species native to Iran.It is naturally widespread as a forest resource in many regions of Iran. In the present study, the pheno-typic diversity of 198 accessions of this species was evaluated using morphological characters. Significantphenotypic diversity was detected among the studied accessions based on morphological traits. Simplecorrelation coefficient analysis showed the existence of significant positive and negative correlationsamong characteristics. The majority of significant correlation coefficients were to be found between thecharacteristics representing nut and kernel sizes. Principal component analysis showed that 73.37% ofthe phenotypic variability was explained by all of traits for the studied accessions where green fruitdimensions, nut dimensions, nut weight, shell weight, kernel dimensions and kernel weight contributedmost of the total variation. Cluster analysis confirmed considerable variation in the studied germplasmand identified two major clusters with several sub-clusters. P. scoparia shows great tolerance to abioticstresses such as drought, salinity, low soil fertility and low winter temperatures; therefore it may presentan important genetic resource to be used in breeding programs and/or directly as a rootstock for almondthat is more adapted to climate change. The present results provide important new information for genepool conservation and screening for superior germplasm and breeding.
