As with other fruit trees, the pomological and chemical characteristics of pomegranate (Punica granatum L.) can vary from year to year and depending on the age of the trees. Physicochemical screening of 19 pomegranate cultivars from a Moroccan ex situ collection, whose fruits were harvested from three different years, showed highly or very highly significant differences for most traits. Indeed, fruit weight, diameter and height were relatively higher in 2017, exceeding the values measured in 2018 by 22.8%, 13.5% and 4%, respectively. The weight and length of the aril, some chemical characteristics such as pH, Brix and maturity index also showed higher values in 2017, exceeding the 2018 values by 3%, 7%, 3%, 14% and 80% respectively. On average over the three harvest years, the 'Chelfi' cultivar had the lowest weight, while the 'Khikhou' variety had the highest value. The weight and yield of the aril varied between 266 mg ('OunH') and 670 mg ('Khik') and 50.65 ('Khik') and 73.34 ('Gord'), respectively. For the chemical parameters, the total soluble solids ranged from 14.52 (Grenade_Jaune) to 17.81 (Sefri 2) °Brix. The maximum value of titratable acidity was found for ‘Negro_Monsteriosa’ (2.87%) and the minimum value for ‘Grenade_Rouge’ (0.37%). The PCA analysis shows the distribution in groups according to the harvest year, which illustrates the annual variance of the characteristics. The hierarchical analysis shows the presence of gene pools with no obvious geographical structure. The results obtained thus provide a basis for the breeding programs of the species.

pomegranate, physicochemical parameters, harvest age effect, diversity, ex-situ collection

Published by University of Zagreb, Faculty of Agriculture, Zagreb, CROATIA
Sponsored by Ministry Science and Education of the Republic of Croatia