The Relevance of Discovering and Recovering the Biodiversity of Apulian Almond Germplasm by Means of Molecular and Phenotypic Markers

Abstract

Almond cultivation has great traditional and economic relevance in Southern Italy, especially in the Apulia region, where almond trees feature an ample and ancient varietal richness. To contrast the loss of plant genetic erosion and to safeguard the available bioresources, as well as to reinforce the local production, the regional Re.Ge.Fru.P. project aimed to re-evaluate, identify, and characterize the Apulian almond germplasm that is still uncharacterized and not jet studied using a dual (genetic and morphological) approach. Collection was conducted in the regional territory of 187 among the most widespread and minor or marginalized genotypes that were molecularly fingerprinted by means of 18 nuclear microsatellites (simple sequence repeats, SSRs). The high number of scored alleles reflected the great level of diversification within the Apulian germplasm, as also confirmed by neighbor joining and structure analysis, that clearly distinguished different genotype clusters. The phenotypic characterization using 17 morphological and phenological descriptors mirrored the genetic results, revealing a high degree of variability. The morphological traits with the best discriminatory ability were nut ventral suture, shell softness and shape and petal color. This work emphasizes the importance of recovering the genetic variability of Apulian almond germplasm, and the need to promote added value and enhance the local agri-food economy.