| Chinese cherry (Cerasus pseudocerasus (Lindl.) G. Don) belonging to the subgenus Cerasus, genus Cerasus, family Rosaceae, is one of the four famous cultivated cherry species with highly economic values. It is an ancient fruit crop originated and distributed in China. The cultivation history can be traced back to 3,000-4,000 years ago. Over such a long-term domestication process, a large number of genetic variations have been accumulated in different landraces populations for catering to various preferences of the consumers and adapting to harsh environmental conditions. These resources differ markedly from their wild progenitors both morphologically and genetically. They contain greater genetic diversity than elite cultivars and represent an intermediate stage in domestication between wild and elite cultivars. Therefore, the investigation of cherry germplasm resources of China and evaluate the important economic characters, discover and use of important economic characters of gene for molecular assisted breeding is an important approach for the development of cherry new varieties breeding. For these problems, Phenotypic variability of 80 Chinese cherry landraces (Cerasus pseudocerasus) from seven populations was assessed based on 26 morphological traits including leaf, fruit and stone phenotype by using nested variance analysis and cluster analysis methods. The main results were shown as follows:(1) There were significant differences in qualitative characters, with shannon-Wiener indexes ranged from 0.61 to 1.64. Among which, the fruit shape (I= 1.64), peel color (I= 1.49), leaf shape (I= 1.40) and lateral shape of stone (I= 1.36) possess relative higher Shannon diversity index; while stone veins (I= 0.61), stone symmetry (I= 0.69) and number of stone keel (I= 0.70) have the lower levels. Considering the various populations, large qualitative variation was also detected among populations. The leaf shape for all accessions is more sub-orbicular (30.00%) and ovate (36.25%). The peel color is largely red (40.00%) and vermilion on yellow (26.25%). The largest variation for stone is the stone symmetry.(2) The analysis of 14 quantitative traits reveals that significant variance for leaf, fruits and stone quantitative traits was detected in both among and within populations, except leaf shape index. This result indicates the widely genetic variation of 14 quantitative traits for both among and within populations. The average variation coefficient (CV) of 14 quantitative traits is 9.93%, with the highest value 24.80% in carpopodium Length, following the length of petiole (19.21%). While the apical view of stone (6.61%) and leaf shape index (7.69%) process the minimum average variation coefficient. Among the seven populations, the highest value of CV was detected in population Yunnan (12.92%), and lowest in population Anhui (7.42%).(3) The first five principal components with the variance cumulative contribution rate of 80.9434% were obtained based on the principal component analysis, which could account for the majority variation of the traits. Among which, the eigenvector of the first principal component is 4.8024, with the largest variance contribution rate 34.3029% at dominant.(4) The total 80 accessions were classified into two major clusters based on Nei's genetic distance cluster analysis and principal coordinate analysis (PCoA). The accessions from Shandong, Henan and Anhui provinces have the minimum genetic distance and closely genetic relationships cluster as north China group. The individuals from Sichuan, Yunnan, Guizhou and Chongqing provinces process the minimum genetic divergence and similar phenotypic character clustering as the southwest China group. This result indicates that the difference of phenotypic diversity of Chinese cherry landraces exists in different geographic populations, and the difference might be caused by domesticated from different geographic sites. |
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