Abstract:

China occupies an important position in the global grape industry, with cultivation area and yield ranking among the top in the world. As a key branch of the fruit tree industry, the grape industry plays a pillar role in increasing farmers' income and rural revitalization. China's grape variety collection has grown, thanks to the introduction of grapes from other countries and new types developed within China. These additions have been a key factor in growing and strengthening the grape industry. However, the increase in variety has also brought about homogenization and identification difficulties, and traditional morphological feature identification methods are no longer suitable for current needs. This investigation entailed the extraction of DNA from 291 table grape germplasm samples. Employing 30 fluorescently-tagged SSR molecular markers, PCR amplification and fluorescent capillary electrophoresis were conducted to establish a molecular fingerprint database for these cultivars. The molecular fingerprint database constructed in this study contains a total of 8730 pieces of information. Further analysis shows that the average number of genotypes for the 30 selected primer loci is 10.7, with a heterozygosity range of 0.21 to 0.62 and an average heterozygosity of 0.38. Based on the number of genotypes at 30 primer loci, 216 varieties were speculated to be diploid, while 75 were polyploid. It was found that the similarity between diploid varieties was generally low, while the similarity between polyploid varieties was relatively high. The results of this study not only provide accurate basis for grape variety identification, but also provide important data for the analysis of genetic relationships of germplasm resources, which is of great significance for theoretical research and practical applications.

Key words: grape, variety identification, ssr molecular markers, genetic diversity