Diversity assessment of the Lebanese germplasm of pomegranate (Punica granatum L.) by morphological and chemical traits

Pomegranate (Punica granatum L.) is one of the oldest edible fruits cultivated in Lebanon but the diversity of its germplasm has not been addressed yet. The present study presents the first assessment of local pomegranates growing in the country. A set of 78 pomegranate local accessions sampled from the main production areas across the country were evaluated by using twenty-eight quantitative and ten qualitative descriptors. A large variability was revealed among accessions based on the traits studied. Principal component analysis showed that male and hermaphrodite flowers, petal width as well as fruit weight, diameter and length, in addition to juice pH and sugar/acid ratio, were the most discriminating traits. Big sized fruits up to 358.6 g were found for Lefani SL67, Lefani ML25 and Mokh El Baghl SL59 accessions while the juiciest fruits were recorded for Mokh El Baghl SL65, Hamod BH41 and Hamod B54 accessions with 75-78%. The PCA bi-plot allowed to differentiate the studied accessions in three main groups based mainly on the juice pH and sugar/acid ratio: the sweet accessions called Helou, the intermediate taste accessions named Lefani and the sour accessions generally designated as Hamod. Although preliminary, the results of this study indicate a significant diversity within the Lebanese pomegranate germplasm that should be further completed by a DNA analysis to understand the genetic structure of this germplasm with respect to conservation and breeding strategies.