关键词: 黄瓜, 果实苦味Bt基因, 基因定位, SSR标记

Abstract: A F2 population including 184 individuals derived from two cucumber inbred lines 931（btbt）and 46GBt（BtBt）was used to construct a linkage of SSR markers to fruit bitterness gene（Bt）in cucumber（Cucumis sativus L.）. Eight SSR markers were mapped on the linkage. The flanking markers SSR10795 and SSR07081 were linked to the Bt gene with genetic distances of 0.8 and 2.5 cM，respectively. The veracity of SSR10795 and SSR07081 was tested using another F2 population，and the accuracy rate for the two markers was 91.6%. The linkage was compared with the integrated genetic and cytogenetic map，and the Bt gene was mapped to the short arm of cucumber chromosome 5 within the region of 3.3 cM. The physical distance between SSR10795 and SSR07081 was 17 227 kb based on the whole genome sequence of cucumber，and there are 536 candidate genes in this region. In the present study，two SSR markers closely linked to Bt gene which could be used in marker-assisted selection（MAS）for non-bitter cucumber breeding program.

Key words: cucumber, fruit bitterness Bt gene, gene mapping, SSR marker