A Comprehensive Evaluation of 45 Pomegranate (Punica Granatum L.) Cultivars Based on Principal Component Analysis and Cluster Analysis

Abstract

ABSTRACT China has abundant germplasm resources of pomegranate. Previous studies have analyzed the fruit quality of the cultivated and wild pomegranates collected from different regions of China. In this study, 45 pomegranate cultivars from Yicheng, Shandong province, China were used as materials. Principal component and cluster analysis was performed based on 18 fruit quality traits. There were significant differences in 18 fruit traits among 45 pomegranate cultivars. Nine principal components (PCs) were extracted by principal component analysis, and the cumulative variance contribution rate was 84.9%. PC1 and PC2 represented 20.9%, 14.3% of total variance respectively. The former was highly positively contributed by total flavonoid and phenolic content of juice, pericarp (FCJ, PCJ, FCP and PCP), and Vitamin C content of juice, while the latter was highly positively correlated with proanthocyanidins and total flavonoid content of seeds (PAS and FCS) and titratable acid content. According to the comprehensive scores, Yushiliu, Gangliu, Mantianhongsuan, Tianlvzi, Xinjianghongpi, Huaiyuanerbenzi, Xiaoqingpi, Damaya, Yichengheshunzhuangwuci, Taishanhong ranked as the top ten. The 45 pomegranate cultivars were clustered into four categories according to 18 fruit quality indicators, each group had unique characteristics. Most cultivars of group III had higher PCJ and proanthocyanidins content of pericarp, while most members of group Ⅳ had higher total anthocyanin contents, FCP and PCP, which suggested that the two groups were rich in functional substances and can be used for further processing. Therefore, the results would provide a method to comprehensively evaluate different cultivars and provide a reference for agricultural cultivation, industrial utilization and breeding.