Pomegranate (Punica granatum L.) is one of the oldest known edible fruits belonging to the Punicaceae family native to the arid regions of Iran and surrounding areas, and then spread in several Mediterranean, American and Australian countries. Pomegranate is one of the richest dietary sources of antioxidant phenols and anthocyanins; in fact in the last decade its popularity has been increasing among growers and consumers worldwide due to the nutritive value and nutraceutical properties of the fruit and to its adaptability to different soils and climate conditions. Pomegranate is characterized by large variability among cultivars in terms of domestic, wild and ornamental genotypes, for characters such as seed-hardness, juiciness, rind and aril colour, sugar/acid ratio, antioxidant activity, fatty acids, phenols and anthocyanins content of arils. The evaluation of pomegranate germplasm has usually been performed using morphological and chemical traits of the fruits, whereas genetic studies received less attention. The aim of the present work was to carry on a morpho-chemical characterization of a set of pomegranate genotypes of different origin (Italian and Israeli) collected in Puglia region, South-eastern Italy, and to investigate their genetic diversity at a molecular level by exploiting microsatellite (SSR) 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, titratable acidity and maturity index. The examined genotypes also showed high total polyphenol content (up to 2829 mg/L) and antioxidant activity (6.35 mM/L). Genetic analysis of the pomegranate collection identified a total of 53 SSR polymorphic loci able to distinguish the different ecotypes at a molecular level. The SSR markers were almost uniformly distributed among pomegranate accessions, in fact we were able to identify only five bands which were exclusive to a specific genotype. Polymorphic SSR loci were used to estimate the genetic distances among the different pomegranate ecotypes, and to build a dendrogram based upon the UPGMA method. Interestingly, cluster analysis was able to separate the different genotypes based on several criteria, that is geographical origin, type (wild or domestic) and morpho-chemical traits such as juice sweetness or total polyphenols content. In general, morphological, chemical and genetic parameters allowed to clearly distinguish the Italian genotypes from the Israeli ones. Our results suggest that SSR markers could be feasible and effective to detect the genetic diversity of pomegranate, thus facilitating the exploitation and utilization of this fruit species germplasm.
CHARACTERIZATION OF POMEGRANATE (PUNICA GRANATUM L.) GENOTYPES COLLECTED IN SOUTHEASTERN ITALY
GIANCASPRO A;
2014-01-01
Abstract
Pomegranate (Punica granatum L.) is one of the oldest known edible fruits belonging to the Punicaceae family native to the arid regions of Iran and surrounding areas, and then spread in several Mediterranean, American and Australian countries. Pomegranate is one of the richest dietary sources of antioxidant phenols and anthocyanins; in fact in the last decade its popularity has been increasing among growers and consumers worldwide due to the nutritive value and nutraceutical properties of the fruit and to its adaptability to different soils and climate conditions. Pomegranate is characterized by large variability among cultivars in terms of domestic, wild and ornamental genotypes, for characters such as seed-hardness, juiciness, rind and aril colour, sugar/acid ratio, antioxidant activity, fatty acids, phenols and anthocyanins content of arils. The evaluation of pomegranate germplasm has usually been performed using morphological and chemical traits of the fruits, whereas genetic studies received less attention. The aim of the present work was to carry on a morpho-chemical characterization of a set of pomegranate genotypes of different origin (Italian and Israeli) collected in Puglia region, South-eastern Italy, and to investigate their genetic diversity at a molecular level by exploiting microsatellite (SSR) 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, titratable acidity and maturity index. The examined genotypes also showed high total polyphenol content (up to 2829 mg/L) and antioxidant activity (6.35 mM/L). Genetic analysis of the pomegranate collection identified a total of 53 SSR polymorphic loci able to distinguish the different ecotypes at a molecular level. The SSR markers were almost uniformly distributed among pomegranate accessions, in fact we were able to identify only five bands which were exclusive to a specific genotype. Polymorphic SSR loci were used to estimate the genetic distances among the different pomegranate ecotypes, and to build a dendrogram based upon the UPGMA method. Interestingly, cluster analysis was able to separate the different genotypes based on several criteria, that is geographical origin, type (wild or domestic) and morpho-chemical traits such as juice sweetness or total polyphenols content. In general, morphological, chemical and genetic parameters allowed to clearly distinguish the Italian genotypes from the Israeli ones. Our results suggest that SSR markers could be feasible and effective to detect the genetic diversity of pomegranate, thus facilitating the exploitation and utilization of this fruit species germplasm.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
