Characterization of pomegranate (Punica granatum L.) genotypes collected in Puglia region, Southeastern Italy

Abstract

The popularity of pomegranate (Punica granatum L.) is increasing among growers and consumers due to its nutritional value, nutraceutical properties and adaptability to different soils and climate conditions. Pomegranate is characterized by a large variability in terms of domestic, wild and ornamental genotypes, and for seed-hardness, juiciness, rind and aril color, sugar/acid ratio, antioxidant activity, fatty acids, phenols and arils anthocyanins content. Evaluation of pomegranate germplasm has usually been performed using fruit morphological and chemical traits, whereas genetic studies received less attention. The aim of the present work was: (a) to carry on a morphological and biochemical characterization of a set of pomegranate genotypes collected in Puglia region, Southeastern Italy and (b) to investigate genetic diversity by microsatellite markers. A two-year study was carried out for the evaluation of 13 pomegranate genotypes, sweet and sour, of Italian and Israeli origin. Significant differences were observed for many of the parameters investigated, in particular fruit and aril size and maturity index of fruits, titratable acidity, total polyphenol content and antioxidant activity of juices and oil content of seeds. Genetic analysis on the pomegranate collection identified 53 SSR loci able to distinguish the different genotypes and to estimate genetic distances. In the dendrogram, pomegranate genotypes clustered according to both geographical origin and morphological–chemical traits (skin color, size, taste and polyphenolic content), suggesting that SSR markers could be effective to detect the genetic diversity of pomegranate, thus facilitating the exploitation of this fruit species germplasm. In general, morphological, chemical and genetic parameters allowed to clearly distinguish the Italian genotypes from the Israeli ones.