Abstract:

In order to establish suitable methods to evaluate jujube quality and consequently guide the development and
utilization of wild jujube germplasms and the selection of excellent germplasms, evaluation and classification of 16 fruit
quality attributes such as single fruit weight, pericarp color, soluble sugar, titratable acid, vitamin C, fruit shape index, and
single stone weight were carried out on 50 germplasms of Ziziphus jujuba var. spinosa by factor analysis and cluster analysis
using SPSS software. The results showed that factor analysis extracted 6 main factors including single fruit weight, single
stone weight, appearance and nutrients, with a cumulative variance contribution rate of 83.173%. Principal component
analysis and cluster analysis were carried out using the loadings of the first 6 principal components. Pericarp color, single
fruit weight, titratable acid (or vitamin C), single stone weight, fruit shape index (or starch content), and soluble sugar
content were selected for cluster analysis of Ziziphus jujuba var. spinosa germplasms. When the squared Euclidean
distance was 14.0, the 50 germplasms could be classified into 4 categories. The first category had better fruit color
with higher acidity, the second one had larger fruits with higher proportion of edible part, and the third one contained
higher sugar contents.

Key words: Ziziphus jujuba var. spinosa, fruit quality, factor analysis, cluster analysis