4.1 Protected the genetic diversity of local tea plant germplasm resources
The success of collecting and preserving germplasm resources depends on the number and distribution of genetic variations present in the resource pool[20]. The Anhui Provincial Local Germplasm Resources Protection Gardon of Tea Trees has been established with the method created in this study, which had 920 samples, with a total of about 100,000 individual plants covering 94% of the local tea planting areas in Anhui Province. The proportion of actual samples is close to the proportion of local tea garden areas in various regions of Anhui Province (Table 1).The samples are widely representative, preserving the genetic diversity of local germplasm resources of tea trees in various regions of Anhui Province.
4.2 Beneficial to the analysis of genetic relationships and population structure characteristics in local germplasm resources
The genome size of tea trees is about 3GB, and their genetic diversity is very rich[5,21]. Classification and identification of tea trees were mainly based on morphological level early. In the 1990s, molecular markers began to be applied in tea plants[22,23]. Subsequently, molecular marker technology was widely used in tea plant genetic diversity, genetic map construction[24,25], QTL analysis[27], and other fields. Currently, SSR[26] and SNP[27,28] have become the mainstream molecular marker technologies in tea trees. Gathering samples from various regions in one place is beneficial to differential observation and research among the samples.
4.3 The base for breeding new varieties
The main goal of tea tree breeding is to select tea tree varieties with high yield, quality, and high resistance to biotic and abiotic stress. At present, tea germplasm existing is one of the most valuable fundamental materials for tea breeding[10]. Among the registered tea tree varieties newly, 85% were applied for through systematic breeding based on local population varieties. Due to the rich genetic diversity,local population varieties have become the main source of tea tree variety breeding.
4.4 Gene retrieval
Protection of resources is not only about short-term but also long-term utilization. With the advancement of modern breeding technology and the application of new varieties, the genetic resources possessed by some local varieties were lost severely, which has been demonstrated in many crop varieties. Some of these lost genes have already been found in the resource pool[29, 30]. The application of clone tea tree varieties will lead to a more severe loss of genetic diversity in local varieties.The localgermplasm resources garden of tea trees can undertake this function—finding gene back.
4.5 Further applications
The collection method created in this study is also suitable for the collection of tea tree sexual-type resources such as wild species and closely related species. The method also provides a reference for the collection and protection of other crops, especially germplasm resources of horticultural fruit trees.