Collection and evaluation of thirty-seven pomegranate germplasm resources

Abstract

Pomegranates (Punica granatum L.) are gaining popularity among consumers because of their high antioxidant activity and multiple medical benefits. China is rich in pomegranate genetic resources, but how to use them effectively is a problem worthy of deep consideration. In this article, thirty-seven pomegranate varieties from seven provinces in China were collected and analyzed for twelve phenotypic traits and twelve biochemical indicators (seeds and juices). The fruit and aril fresh weight ranged between 210.5 and 576.5 g and 121.0 to 327.5 g, respectively, and the edible rate (42.58–64.80%), seed weight (1.80–3.41 g), seed number (249.1–838.9), fruit height (10.51–15.48 mm), fruit diameter (11.46–17.50 mm), skin thickness (2.14–6.98 mm), and shape index (0.82–0.96) varied among the different genotypes. The pomegranate juice total phenolic content ranged from 40.91 to 132.47 µg/mL, and the total flavonoid content (14.08–137.72 µg/mL), vitamin C content (12.80–66.63 µg/mL), pH (3.10–4.34), total soluble solids (13.13–17.50°Brix), and titratable acidity (0.26–2.71%) also varied; the pomegranate seed total phenolic content ranged from 0.62 to 1.78 mg/g, and the total flavonoid content (0.39–0.99 mg/g), vitamin C content (7.55–13.90 mg/g), DPPH radical scavenging capacity (85.98–98.24%), and ABTS scavenging ability (28.72–51%) were also measured. The coefficients of variation of the studied traits ranged from 5.62 to 54.02%, and the phenotypic traits’ Shannon–Weaver diversity indexes ranged from 0.67 to 1.53. Cluster analysis divided the 37 varieties into three categories, providing a reference for improved variety breeding. In addition, genotypic and environmental effects mainly affected the pomegranate flavor and antioxidant activity, respectively.