Assessment of genetic diversity of Camellia yuhsienensis based on leaf structure and inter simple sequence repeat (ISSR) markers

Genetic diversity provides valuable genetic resources and forms the basis of plant breeding. Plant leaves are closely connected to the external environment and play important roles in plant growth and development. Here, 13 cultivars of Camellia yuhsienensis were collected from Southern China to examine the magnitude of genetic diversity and differentiation, using cluster analysis based on 21 leaf traits and ten Inter simple sequence repeat (ISSR) markers. Morphological study indicated that all traits varied to different degrees, indicating a high degree of genetic diversity in C. yuhsienensis. Eight typical leaf characteristics were screened using principal component analysis, which showed that the selected traits were highly correlated and clustered. Average polymorphism percentage was obtained from the ISSR marker pattern using ten primers. A total of 201 loci were amplified, of which 175 were polymorphic with an average polymorphism percentage of 87.06%. Polymorphism information content (PIC), marker index (MI) and resolving power (RP) revealed that the selected primers were found to be informative in distinguishing C. yuhsienensis germplasm resources. Nei's diversity Index and the Shannon’s diversity index values indicated a certain level of genetic diversity. Cluster analysis results based on leaf structure and molecular markers were generally consistent, indicating a high degree of effective loci for morphological markers of C. yuhsienensis. Our results revealed genetic differences and commonalities among the cultivars, providing valuable information to identify appropriate seedling cultivars and conserve germplasm resources for future utilization.