Large-Scale Screening and Identification of Alleles in Chinese and European Apricot Accessions Reveal Their Diversity and Geographic Distribution Patterns.

Apricot ( L.) exhibits a gametophytic self-incompatibility (GSI) system. To identify the -genotypes of the main apricot cultivars, including 133 native Chinese cultivars and 35 foreign accessions, PCR was performed using a combination of five primers based on the conserved regions of genes. After cloning and sequencing the PCR products, the -genotypes of all 168 apricot cultivars were determined. A total of 46 different alleles, with 15 new alleles, were identified. For all 168 accessions, the top five most frequent were , , , , and . , , and were the most frequent in Chinese cultivars, and , , and were mostly found in European accessions. For Chinese apricot cultivars, the distribution of among five geographic regions was also investigated. In Northwest China, was the most frequent . In the Xinjiang region, , , and were the top three most frequent . In North China, , , and were the top three most frequent . In addition, the self-compatible type, , was not detected in these 133 Chinese accessions. Finally, the phylogenetic tree of apricot indicated that there are four groups of genes (/, //, //, and /) presenting a very close relation. These results provide more data on the -genotypes of apricot accessions, which can support future breeding programs by aiding in the selection of the appropriate parents and contributing to efficient orchard design by combining cultivars with suitable pollinizers.