Research On Inheritance Of Monoecious And Gene Map On Melon (Cucumis Melo.L)

Melon is an important economic group in cucubit. Most of melon were andromonoecious, monoecy can not only reduce the hand pollination but also can improve the quality of F1 hybrids than other andromonoecious accessions. So, the monoecious become to an important goal for melon breeding. Investigation sex expression on different generations from different crosses to analysis the inheritance of monoecious and identify the molecular markers which linkage to monoecious character. The possibility of Markers-assisted selection was explored in monoecious analysis which could speed up seed breeding process and develop a new method on melon breeding.Parental lines were: female parent 3-2-2 from China, thin-skinned melon, monoecious; male parent TopMark, from USA, thick-skinned and netted melon, andromonoecious; tested parent WI998, from USA, netted melon, gynoecious. Investigated the sex type and expression of F1, F2 and BC generations from crosses 3-2-2×TopMark, WI998×TopMark, WI998×3-2-2, respectively to confirm the genotype of different sex performance on melon. Using 350 F1 generations from 3-2-2×TopMark to constructe recombination inbreed lines, acqurie 152 F1S6 generations to constructe genetic map.Sex expression was controlled by a domiance gene with two mine genes and modify gene after investigated the sex performance of F2 and BC generations from cross 3-2-2×TopMark, main-gene heridity was 83.3% and mine-gene heridity was 8.125%. Ensured the performance was controlled by two dominance gene after investigated the F2 generation from WI998×3-2-2, and three gene controlled sex performance of cross WI998×TopMark. Segregation of every generation were investigated and confirmed the genotype of 3-2-2(monoecious)was AA, and the genotype of TopMark (andomonoecious)was aa. The M was modify gene and exist another modify gene F to coorperate with M gene to controlle Trimonoecious and Gynomonoecious.Selected 428 SSR markers which included 380 pairs of EST–SSR markers and 48 pairs g-SSR markers, 94 primers were polymophic which the size from 150~300bp; selected 22 primers were polimophic in 256 AFLP EcorI/MseI primers, and 146 polymophic sits from 100~600bp.Using RILs genrations of 3-2-2×TopMark to construct genetic map, a total of 70 SSR markers, 100 AFLP markers and one agronomic traits was grouped in to 17 large linkage groups which spanned 1222.9cM with an average marker interval of 7.19 cM. The longest linkage group was LG1(spanning 197.4 cM)and the shortest group was LG3(spanning 11.0 cM). Ten markers in the same linkage group with A gene and the group spanning 55.7 cM, SSR marker MU13328-3 and AFLP marker e33m43-1 were linkage to A gene with 4.8 cM and 6.0 cM, respectively.Identified the genotype of monoecious and studied on inheritance of monoecious will not only increase the saturation of genetic map on molecular markers but also have the theoretics value on gene seperation and mapping clone of monoecious melon.