Investigation and fruit genetic diversity analysis of wild Actinidia germplasm resources in Tongshan County, Hubei Province

To explore the distribution status, breeding value, and conservation and rational development and utilization of wild Actinidia germplasm resources, we carried out field investigation and genetic diversity analysis of wild Actinidia germplasm resources in Tongshan County, Hubei Province, China. Results showed abundant germplasm resources and high species diversity in Tongshan County. Seven species (including varieties) were found, most of which were A. chinensis Planch. In total, 152 wild Actinidia germplasm resources were collected and recorded. Altitude spanned 210-1429 m. Ploidy was identified as diploid or tetraploid. In total, 44 fruits of A. chinensis were collected. Based on 15 phenotypic characters, the coefficients of variation of the different characters ranged from 24.66% to 75.76%. The genetic diversity index ranged from 0.35 to 2.02, and phenotypic characters, such as fruit shape and size, showed marked genetic differences. Principal component analysis and comprehensive quality evaluation of 22 Actinidia germplasms were carried out based on 11 quantitative characters. Results showed that the cumulative contribution rate of the first four principal components reached 83.42%, and cluster analysis indicated that the resources could be divided into three categories. These abundant resources can provide original materials for the breeding of superior germplasms and genetic improvement of varieties. Suggestions and strategies for strengthening the development, utilization, and genetic protection of wild resources are also discussed.