Identification and purity test of melon cultivars and f₁ hybrids using fluidigm-based snp markers

In melon (Cucumis melo L.), the grow-out test (GOT) has been traditionally used as a genetic purity test. However, this method is time-consuming, space-demanding, and associated with ambiguous classification of the genotypes. Molecular markers have proved to be an efficient tool in genotyping analyses. In the present study, a total of 96 genome-wide single nucleotide polymorphism (SNP) markers differentiated 85 melon F₁ hybrid plants from their parental lines and six other PT melon breeding lines via high-throughput Fluidigm genotyping. Of these, 39 SNP markers showed polymorphism between the parents. Additionally, SNP analysis and population structure analysis showed that several F₁ hybrid plants were associated with outcrossing during the breeding program. Unweighted pair group method with arithmetic average (UPGMA) analysis revealed that most of the contaminated plants were closely sub-grouped with the 7_PT1 breeding line, suggesting possible outcrossing with 7_PT1. By combining with simple DNA extraction, the Fluidigm-based SNP marker analysis proved to be a simple and effective approach for the genetic purity analysis of F₁ hybrids and melon cultivars.