Performance and genotypic variability in diverse date palm (Phoenix dactylifera L.) cultivars for fruit characteristics

Identification of date palm cultivars is primarily based on fruit characteristics while the morphological characteristics of the trees have less importance. Exploring genotypic variability in date palm cultivars is indispensable for enhancing sustainable utilization, dynamic conservation, and the development of new germplasm. Accordingly, 16 diverse date palm cultivars from different sites in Saudi Arabia were evaluated for various fruit characteristics in the present study. The assessed date palm cultivars exhibited highly significant differences in all studied fruit characteristics. The highest fruit length was displayed by Um-Kbar, Wannana, Medjool, and Sefri cultivars, while the largest width of fruits was assigned to Rushodia, Um-Kbar, and Wannana. Fruit weight and volume were significantly higher in Um-Kbar, and Medjool than those in other cultivars. On the other hand, the Medjool, Hilali, Thawee, and Sefri cultivars recorded the highest soluble solid content. Um-Kbar, Khesab, and Hilali recorded the highest acidity percentage (more than 0.60%). The phenotypic variance (PV) values of all studied characteristics were higher than the genotypic variances (GV). Additionally, the phenotypic coefficient of variation (PCV) was larger than the genotypic coefficient of variation (GCV). The highest PCV and GCV values were observed for the length of basal appendages, whereas the lowest values were assigned for fruit length. All studied characteristics displayed high heritability (h2b), varying from 99.61 (of fruit volume) to 84.49 (of seed length). Expected genetic advance (GA) values ranged from high for fruit weight to low for seed width. The results of the principal component analysis revealed that most of the variation was explained by the two components. Accordingly, they were employed to construct PC biplot to present the association between evaluated cultivars and studied fruit characteristics. The studied cultivars were clustered based on fruit characteristics into six groups ranging from high to low performance.