Rapid Characterization of the Genetic Loci Controlling Commodity Traits of Chinese Hami Melon (Cucumis melo var. Saccharinensis Naud.) through Multiplexed Shotgun Genotyping

Abstract

The genetic architecture and the genetic loci controlling commodity traits in this Hami melon have not been characterized. Multiplexed shotgun genotyping (MSG) was used to genotype an F2 population of 370 Chinese Hami melon progeny. A total of 47,609 single nucleotide polymorphism (SNP) markers were obtained after strict filtering. Thebins were used to construct a genetic linkage map with a total length of 1572.954 cM. Quantitative trait locus (QTL) analysis revealed that fruit color was controlled by one major gene about 2 Mb region on chr09, while exocarp color (EC) was controlled by one major gene about 1.9 Mb on chr04, and skin spotting was controlled by two dominant genes, one in the same region of chr04as the EC QTL and the other in the 1031.05 kb region on chr02. Two major QTLs on chr03 and chr05 were related pleiotropically to several quantitative fruit traits, namely, edge sugar content (ES), center sugar content (CS), fruit weight (FW), and fruit length (FL). A further QTL on chr09 also influenced ES, while five other QTLs affected FL. This study was the first to conduct genetic architecture analysis and QTL mapping in Chinese Hami melon with high-density markers and a large target population.