Genetic variation of tea plant in Ningde and its adjacent regions revealed by single nucleotide polymorphism genotyping

Ningde (ND), situated in China's prominent tea-producing region, is recognized as the origin of white tea. It also boasts a wealth of premium tea germplasm resources, which are of vital importance in tea breeding programs. In this investigation, utilizing nanofluidic single nucleotide polymorphisms (SNPs) genotyping technology, the genetic diversity and population structure of tea germplasms sourced from ND and its surrounding regions were scrutinized. A comprehensive collection of 101 tea plant germplasm accessions sourced from ND and its neighboring regions was acquired. Our analysis identified 75 stable and reliable SNP loci that demonstrated the rich genetic diversity of the ND tea germplasms, with an average observed heterozygosity of 0.411 and an expected heterozygosity of 0.382. Notably, the multiple analyses based on high-quality SNPs revealed that the wild-type landraces of tea plants in ND are genetically distinct from the cultivars. The analysis of molecular variance results suggested that intrapopulation variation contributed to 79% of the total genetic variation. Moreover, tea plant germplasms in ND interacted with the genetic material of landraces in Nanping and Lishui. Overall, our study provides essential insights into the genetic diversity, relationship, and conservation of ND tea germplasms and lays a molecular basis for innovative utilization and breeding improvement of tea plant germplasms. Single nucleotide polymorphism genotyping was used to analyze the genetic diversity and population structure of 101 tea germplasms.A total of 101 tea germplasms exhibited relatively high genetic richness.There was more exchange among landraces and provincial cultivars, but less among wild tea germplasms.The main genetic variation came from intra-area differentiation.Overall, there is a vast reservoir of genetic diversity in the tea germplasms from Ningde.