Genetic Analysis Of Controlling Staminate Expression Gene And Preliminary Mapping Of Melon

Melon(Cucumis melo L.)is a kind fo trailing herbage plant and the fruit which is edible belongs to the Cucumis genus, Cucurbitacleae family. Melon(Cucumis melo L.)display a range of sexual phenotypes including various combinations of male, female, or bisexual flowers. Gynoecious phenotype is of great value in utilization of heterosis in melon (Cucumis melo L.) because artificial emasculation can partially be avoided and hybrid purity can be ascertained. In this paper genetic analysis of melon sex express was carried out to use the F2 and BC1 data. Meanwhile on the basis of expatiating the genetic disciplinarian of An the mark linking with An gentic locus tightly were acquired by SSR marker technology. The content of experiment is as follows.1. The gynoecious melon(Cucumis melo L.)line WI998 (absence staminate) was crossed as female with the monoecious melon line 3-2-2 (presence staminate). The F1 generation was all monoecious. The ratio of sex expression on F2 generation of the crossing segregated was 3 (presence staminate) : 1(absence staminate). The F1 was backcrossed as male to WI998, and the ratio of sex expression on BC1P1 generation segregated was 1(presence staminate): 1 (absence staminate). whereas the F1 was as male backcrossed to 3-2-2, and the ratio of sex expression on BC1P2 generation was all presence staminate. The results indicated that a dominant gene control the differentiation of staminate flowers on melon. The gene was named as An.2. The F2 population was used to construct the genetic mapping of melon and to map the An gene using simple sequence repeat (SSR) markers in this research. The mapping consisted of 5 linkage groups, contained 18 SSR markers and 1 morphological marker. It spanned total of 442.7cM genetic distance with a 24.6cM average interval.3. Two SSR markers, which was MU4128-2 and MU5028-1, were mapped near the An gene. Linkage analysis indicated that the An gene was located on the linkage group 2. These markers distance of An gene were 42.8cM and 26.0 cM respectively.