Selection of superior late-blooming almond (Prunus dulcis [Mill.] D.A.Webb) genotypes using morphological characterizations

Abstract

Almond (Prunus dulcis [Mill.] D.A.Webb) is one of the earliest domesticated trees and the evidence dates back to 3000–2000 BC. In the present study, 198 almond seedling origin trees were studied to select late-flowering genotypes having high kernel quality. Significant variabilities were exhibited among the genotypes investigated based on the recorded traits. Full-blooming date ranged from mid-March to mid-April. The Ward dendrogram clustered the genotypes into two major clusters forming several subclusters. After clustering the genotypes based on the full-blooming dates, 68 late-blooming genotypes were recognized and reanalyzed based on the quantitative characters to select the superior ones. Nut-related characters were as follows: nut length: 22.34–43.05 mm, nut width: 14.07–24.34 mm, nut thickness: 9.21–18.00 mm, nut weight: 1.88–6.62 g, and shell thickness: 2.26–4.59 mm. Kernel-related characters were as follows: kernel length: 16.73–25.91 mm, kernel width: 8.50–13.64 mm, kernel thickness: 3.56–7.37 mm, and kernel weight: 0.35–1.41 g. Kernel weight was positively and significantly associated with nut weight, kernel thickness, kernel length, kernel width, nut length, and branch leaf width. Thus, these key variables are the main traits accounting for kernel weight, and they should be considered together in breeding with aiming at increasing the kernel weight. Based on ideal values of the important and commercial characters of almond, such as fruit yield, nut weight, shell hardness, kernel shape, kernel weight, and kernel taste, 19 late-blooming genotypes were promising and are recommended for cultivation in orchards.