ZHANG Yuexing, ZHANG Ruiqing, XIAO Yuzhen, DAI Xue, ZHANG Yong, WANG Zhongyuan, YU Rong, HOU Yinjie, ZHANG Xian, WEI Chunhua
This study aimed to develop kompetitive allele specific PCR（KASP）markers suitable for genotyping and fingerprint map construction of watermelon germplasms，so as to enhance the protection of watermelon germplasm resources，variety identification，and genetic improvement．Based on the highquality single nucleotide polymorphism sites（SNPs）identified through the re-sequencing data analysis of watermelon，50 KASP markers were designed and employed for genotyping 43 watermelon accessions．Genetic diversity was assessed via cluster analysis and fingerprinting．The overall success rate of KASP marker design was 40.0%，with signifi cant variations across chromosomes．Notably，chromosomes 1 and 7 had the highest success rate of 75.0%．Sixteen optimal KASP markers were selected for genotyping the 43 watermelon accessions．Their genotyping results were used to establish standardized fi ngerprint maps，which were then encoded into two-dimensional codes．This allows for quick retrieval of genetic information and identifi cation of watermelon materials．Cluster analysis revealed that watermelon accessions from Citrullus amarus predominantly formed a distinct clade with close genetic relationship．In contrast，accessions from Citrullus mucosospermus and Citrullus lanatus were broadly distributed across multiple branches，indicating signifi cant genetic divergence and complexity．This research has successfully established and applied KASP technology for watermelon，off ering a new tool for watermelon genetic research and germplasm resource evaluation．It also provides a scientifi c basis for watermelon cultivar identifi cation and germplasm management．
