Inheritance Analysis And Location Of The Gynoecious Trait In Cucurbita Maxima

The pumpkin is widely planted in our country, which has the characteristics of wide variety and rich nutrition. In order to improve the pumpkin fruit setting and the yield of pumpkin rises, the research and utilization of subgynoecious is necessary. At present, there are few studies about subgynoecious being reported, so this experiment is a preliminary study of subgynoecious. In this study, the subgynoecious line 2013-12 as female, the strong male line 9-6 as male, P1, P2, F1, F2, BC1, BC2 six generations derived from this cross, then field survey. Analysis the inheritance of pumpkin Subgynoecious and the first node female flower, using SSR and CAPS markers to fin d the gene positioning of pumpkin Subgynoecious. The results were as follows:(1)Female flower rate within 20 nodes for six population(P1, P2, F1, F2, BC1, BC2)was counted. according to the statistical results of ratio of separation, through χ2 test, that India pumpkin Subgynoecious is controlled by a major gene, but the analysis shows that it may still exist other minor genes. Use the mixed major gene plus polygene inheritance model to analysis, it shows that the Indian pumpkin Subgynoecious were controlled by one major gene with negative dominance effects and the polygenes with additive- dominance effects model.(2)The first node female flower within 20 nodes for six population(P1, P2, F1, F2, BC1, BC2)was counted. It shows that the first node female flower of P1 populations is lower, the average is 5.52 knots, the first node female flower of P2 populations is higher, the average is 14.57 knots; The average of the first node female flower of F1 populations is 9.08 knots, between the parents. The first node female flower of F2 populations showed normal distribution, which shows that control of the first node female flower of pumpkin gene is a quantitative trait, suggesting the traits of the first node female flower were controlled by two major genes with additive-dominance-epistemic effects and the polygenes with assitive-dominance effects model.(3)Using SSR and CAPS markers, one maker CAPS12 was found out which is linked to subgynoecious locus. The selected marker was tested with individual of F2 population, it shows that the maker was linked to subgynoecious locus. The genetic between the maker and subgynoecious locus was 8.1 c M.