Abstract:

To gain an in-depth understanding of the genetic diversity of the Prunus salicina ‘Fengtang’ cultivated population, a quantitative classification study was conducted on 26 fruit traits of 74 single plants in the P. salicina cultivated population (12 quantitative and 14 descriptive traits). The fruit traits were compared with those of P. salicina ‘Fengtang’ to provide reference for scientific conservation and rational exploitation of local plum resources in Guizhou. The trait distribution frequencies, coefficients of variation, Shannon-Wiener information index, Simpson genetic diversity index, epistatic clustering, principal component analysis and significant difference analysis were used to analyze and study the traits according to the Specifications and Data Standards for the Description of Plum Germplasm Resources. The results are as follows. (1) The ranges of Shannon-Wiener diversity index and Simpson genetic diversity index for the 26 fruit traits were 0.3425-2.1838 and 0.1928-0.8775, respectively. Among the 14 descriptive traits, no variation type was found for kernel shape, while 2.9 average variation types occurred for the remaining descriptive traits. The coefficients of variation for 12 quantitative traits ranged from 0.50% to 31.92%. Among them, the coefficient of variation of Vc was the largest, followed by single fruit weight. (2) The results of the Q-cluster analysis showed that at the Euclidean distance of 16.65, the 74 materials could be divided into four clusters, A, B, C and D. The number of materials in each cluster was 16, 12, 28 and 18 in order. Among them, group A, group B and group C were more closely related to P. salicina ‘Fengtang’. Group D was more distantly related to P. salicina ‘Fengtang’, and most of the fruit quantitative traits of group D and P. salicina ‘Fengtang’ were significantly different. (3) The results of R-type cluster analysis showed that at the correlation coefficient of 2.08, the 26 fruit traits could be divided into two major groups, and the first major group was group A. At the correlation coefficient of 1.35, the second major group could be divided into group B, group C and group D. Combined with the correlation analysis of quantitative traits, it was found that most of the traits showed pairwise correlations with each other, and some of the traits showed obviously logical correlations with each other. (4) Principal component analysis revealed that there were nine principal components with eigenvalues greater than 1.0. Their cumulative contribution rate reached 70.79%, among which the contribution rate of each trait was more dispersed. This indicated that the classification of the probable P. salicina ‘Fengtang’ germplasm was influenced by several traits together. In conclusion, it can be concluded that the 74 individual plants of the P. salicina ‘Fengtang’ cultivated population were rich in fruit trait diversity, with more types of descriptive trait variation, more obvious quantitative trait variation, and rich genetic diversity. There were strong correlations in 26 fruit phenotypic traits, and it was a reasonable method to use fruit traits for quantitative classification study of the test material. The study yielded 18 germplasm resources that are distantly related to P. salicina ‘Fengtang’, which can be conserved and utilized as important resource materials.

Key words: Prunus salicina ‘Fengtang’, cultivated population, genetic diversity, fruit trait, cluster analysis, principal component analysis