Study of the genetic diversity of almond seedling populations in Morocco: application of chemometric approach

Abstract

Almond (Prunus amygdalus Batsch) in Morocco is still propagated by farmers mostly from seed, generating a large genetic diversity. Evaluation of the almond diversity in Morocco from the point of view of kernel quality, oil and protein contents, and major fatty acid composition were determined. Principal component analysis (PCA) was used to compare the kernel components among 46 genotypes selected from different production regions, as well as five introduced cultivars. Oil and protein contents were highly variable between genotypes, ranging respectively from 48.29 to 65.19% and from 14.07 to 36.48% of the total kernel dry weight. Fatty acid composition of the oil fraction ranged between 5.6-8.34% for palmitic acid, 0.37-0.87% for palmitoleic acid, 1.3-3.3% for stearic acid, 57.95-81.97% for oleic acid, and 9.69-29.98% for linoleic acid. Clustering of genotypes from similar regions suggested the existence of parental relationship among these genotypes and, as a consequence, a common ancestral origin. The Moroccan genotypes did not cluster separately from the introduced varieties. Two genotypes had very high oil contents whereas four genotypes had exceptionally high protein contents (>30%). One genotype had a very high oleic content (82%). The large variability observed for oil and fatty acid composition and the presence of genotypes with higher oil and fatty acid contents than the foreign cultivars represent a very promising base to obtain new Moroccan almond cultivars with oil of higher quality.