Abstract
Pumpkin (Cucurbita moschata) is an economically worldwide crop. Few quantitative trait loci (QTLs) were reported previously due to the lack of genomic and genetic resources. In this study, a high-density linkage map of C. moschata was structured by double-digest restriction site-associated DNA sequencing, using 200 F2 individuals of CMO-1 × CMO-97. By filtering 74,899 SNPs, a total of 3,470 high quality SNP markers were assigned to the map spanning a total genetic distance of 3087.03 cM on 20 linkage groups (LGs) with an average genetic distance of 0.89 cM. Based on this map, both pericarp color and strip were fined mapped to a novel single locus on LG8 in the same region of 0.31 cM with phenotypic variance explained (PVE) of 93.6% and 90.2%, respectively. QTL analysis was also performed on carotenoids, sugars, tuberculate fruit, fruit diameter, thickness and chamber width with a total of 12 traits. 29 QTLs distributed in 9 LGs were detected with PVE from 9.6% to 28.6%. It was the first high-density linkage SNP map for C. moschata which was proved to be a valuable tool for gene or QTL mapping. This information will serve as significant basis for map-based gene cloning, draft genome assembling and molecular breeding.
Highlights
IntroductionIn spite of the economic and nutritional significances of C. moschata, there were limited genomic and genetic resources available compared with other cucurbits, such as cucumber, melon and watermelon for which microarrays[5,6], dense genetic maps[7,8,9], reverse genetic platforms[10,11], transcriptomes[12,13,14,15,16] and even whole genome sequences[17,18,19] have been developed and completed
This study described the construction of the first high-density linkage map of C. moschata using SNP markers developed by double digest restriction-sites associated DNA sequencing (ddRAD) technology
A high-density linkage map consisting of 20 linkage groups (LGs) was constructed based on 3,470 SNPs filtered through 74,899 polymorphic SNPs
Summary
In spite of the economic and nutritional significances of C. moschata, there were limited genomic and genetic resources available compared with other cucurbits, such as cucumber, melon and watermelon for which microarrays[5,6], dense genetic maps[7,8,9], reverse genetic platforms[10,11], transcriptomes[12,13,14,15,16] and even whole genome sequences[17,18,19] have been developed and completed. With the reason that saturated high-density genetic map is the significant tool for QTL mapping, high-density linkage maps were constructed for cucurbits, such as cucumber, melon, watermelon, C. maxima, C. pepo and wax gourd[31,32,33,34,35,36,37]. Taking advantage of these maps of C. maxima and C. pepo, several pumpkin QTLs were successfully identified[31,33,36]. The genetic map and QTLs can be used for support of breeding for genetic improvement of pumpkin
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call