Diversity based on molecular markers and agronomic traits and interspecific crosses among Cucurbita spp.

摘要

We have analyzed the genetic diversity of 45 squash genotypes in Cucurbita maxima, C. moschata, C. pepo and unidentified Cucurbita spp. (noodle-squash) with molecular markers. The 45 squash accessions showed molecular variations of 87.5 percent in RAPD and 74.4 percent in AFLP, respectively, which allowed to group them into 3 clusters at the genetic similarity of 54 percent. Noodle-squash lines were grouped into the same cluster with C. pepo at 89 percent similarity level. Genetic similarities within individual sub-groups were 97 percent in noodle-squashes, 96 percent in C. pepo, 98 percent in C. moschata, and 98 percent in C. maxima, respectively. Korean, Japanese, and American noodle-squashes were separately grouped at the similarity of 97 percent. Since there were no distinct molecular markers to distinguish the noodle-squashes and C. pepo in our study, we suggest that the noodle-squash could be one of the different ecotypes of C. pepo. In the agronomic traits of the noodle-squashes and threeCucurbita spp., the noodle-squash showed closer to the C. pepo than the other two Cucurbita species. In inter-specific crosses with the noodle-squash, the noodle-squash/C. pepo showed higher fruit and seed setting than the other cross combinations. Theseresults will be helpful to the studies of squash breeding programs.