关键词: 西瓜, 耐裂, KASP分子标记, 基因型, 种质资源, 果皮硬度, 果实性状, 大果型, 小果型

Abstract: The cracking resistance of watermelon germplasm resources was identified and evaluated，to provide support for enriching elite cracking⁃resistant breeding materials of watermelon.92 watermelon germplasm accessions were used as test materials，to conduct genotypic analysis by KASP molecular marker linked to cracking⁃resistant traits.And a correlation analysis was further carried out in combination with fruit traits including pericarp hardness，pericarp thickness，fruit shape index，single fruit weight，central soluble solids content and pericarp color.The results showed that 42 watermelon germplasm accessions with cracking⁃resistant genotypes were identified via KASP genotyping.The genotype was significantly correlated with pericarp hardness，and the pericarp hardness of the cracking⁃resistant genotype（GG） was higher than that of the cracking⁃susceptible genotype（AA）.Through the combined identification of cluster analysis based on pericarp hardness and genotyping，17 germplasm accessions of small⁃fruited watermelon with medium to high pericarp hardness and cracking resistance were screened out，including HY⁃20，HY⁃25 and Siweite No. 2. 25 germplasm accessions of large⁃fruited watermelon with medium to high pericarp hardness and cracking resistance were identified，including A3，W10 and Yubao No. 1. Pericarp hardness and the KASP molecular marker for cracking resistance can be applied to the screening of cracking⁃resistant watermelon germplasm and marker⁃assisted breeding. And the screened cracking⁃resistant germplasm resources can serve as elite parental materials for the breeding of new cracking⁃resistant watermelon varieties.

Key words: Watermelon, Cracking resistance, KASP molecular marker, Genotype, Germplasm resources, Pericarp hardness, Fruit trait, Large?fruited type, Small?fruited type