Genetic Diversity of Nut Characteristics in Some Wild Almond Species in Southern Zagros Region of Iran

Iranian wild almond species are valuable plant genetic resources which can be used for almond cultivar and rootstock breeding programs. In this respect, the Amygdalus scoparia holds an outstanding position. To evaluate the genetic variability of the nut characteristics, six populations of A. scoparia from different regions of Fars province including Shiraz, Marvdasht, Firuzabad, Eqlid, Nourabad and Fasa as well as one population from Boroujen region in Chaharmahal and Bakhtiari province along with three populations of other species including A. dulcis, A. eburnea, and A. eleagnifolia were studied. For this purpose, in each population, some genotypes were selected in their natural habitats and after recording their geographic data, the nut samples were collected and transferred to the laboratory. Twelve quantitative and four qualitative traits of nuts were evaluated according to the almond descriptor. Results showed that there are considerable genetic variations in the studied nut traits within and between the populations. Among A. scoparia populations, Shiraz population was superior to other populations in most of the nut attributes. However, among the studied species, common almond (A. dulcis) had the biggest nut. Interesting and significant correlations were seen between measured nut characteristics, among which the highest correlation (0.94) was observed between nut length and nut weight. Using cluster analysis, genotypes were placed in two main clusters of wild and domestic populations. The main cluster of wild populations was divided into four sub clusters based on geographic proximity and species. In general, this evaluation demonstrated that there is a considerable variability in nut characteristics of the studied wild almond species, especially in A. scoparia, which could be utilized in future breeding programs.