| The cucumber is one of main cultivation vegetable crops in China. Consequently,it has the important theoretical and applied significance to develop cucumber molecular breeding research. Constructing the saturated genetic map of cucumber is the foundation to carry out the cucumber molecular breeding.It will provide a accurate quick tool for the new varieties selective breeding and the molecular mark auxiliary breeding. Although the construction molecular genetic map of cucumber had already made the important progress, the published cucumber genetic maps at present are from the different laboratory, using diffent mapping parents and markers. These maps are constructed based on F2 populations. The degree of saturation are not high. Accordingly,it lacks the versatility and the usability. This research was based on the mapping strategy of"anchor SSR mark".At first,we used two F2 populations and selected 940 pairs of SSR primers to construct genetic map of cucumber anti-powdery mildew and the anti-wilt disease molecular.Then we carried on the original cucumber anti-viral disease genetic map to integrate them.At last ,we obtained a cucumber genetic map which was based on the SSR mark. While completed the construction of the map, we localized the genes for the important disease-resistance characters, such as blight,powdery mildew and viral disease. The work sheet that we obtained after the conformity the genetic map of cucumber will have the very strong usability in cucumber genomics and the molecular breeding research.My research has led to the following results.1. The construction and intergration of map.1.1 Used the F2 segregation populations between WIS2757 and 19032 , a map with 161 markers ( AFLPs, SSRs, SCARs and RAPDs ) was constructed in cucumber. These locus were mapped to 10 linkage groups, spanning a total genetic distance of 824cM, with an average interval of 5.1cM per marker, of which the length of linkage group varied from 43cM to 158cM and the average genetic distance was between1.5cM/maker(G1)~19cM/maker(G9) .The number of markers on every linkage group varied from 4 to 90.SSR is distributed homogeneously on 10 linkage groups and each of them contain 2 markers at least and 16 markers at most.1.2 Used the F2 segregation populations between WIS2757 and Jinyan NO.2, a map with 164 markers ( AFLPs, SSRs, SCARs and RAPDs ) was constructed in cucumber. These locus were mapped to 9 linkage groups, spanning a total genetic distance of 530cM, with an average interval of 3.2cM per marker,of which the length of linkage group varied from 22cM to 196cM and the average genetic distance was between 1.2cM/maker(G1)~8.6cM/maker(G9) . The aera overlaid 30% of the map,of which the distance between two markers was smaller than 10cM.There were fifteen gaps exceed cM and the maximal gap was on linkage group G9(24.5 cM). 1.3 Used the RIL population of a cross between European No. 8 and QiuPeng, a map with 311 markers ( AFLPs, SSRs, SCARs, RAPDs and morphological traits) was constructed in cucumber. These locus were mapped to 10 linkage groups, spanning a total genetic distance of 934 cM, with an average interval of 3.0cM per marker,of which the length of linkage group varied from 40cM to 158cM . The markers on the linkage group varied from 4 to 110.There were 61 SSR markers added to integration map and most of them were added to G3,G10.2. Localization of resist-disease gene.2.1 Three resistance genes to ZYMV-CH, WMV and PRSV-W were mapped into linkage group 3 within 15cM genetic distances. Mapping of the WMV resistance gene was the first reported. This research was the first time that three viral resistance genes were mapped in the genetic map and their poly-grouping was affirmed in the molecule level.2.2 Mapping the resistance genes to blight pm into linkage group 1 and the resistance genes to powdery mildew Fw into linkage group 10,we obtained the close linkage molecule markers.
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