应用SSR和SRAP标记构建青虾遗传连锁图谱

摘要

采用SSR和SRAP标记结合拟测交策略构建青虾(Macrobrachium nipponense)遗传连锁图谱.共有175个标记(含27个SSR、148个SRAP标记)分布在53个连锁群上.每个连锁群含2～8个标记,其中不少于3个标记的连锁群有35个,连锁对18个,平均每个连锁群的标记数为3.3个；连锁群长度在6.7～91.2 cM之间,相邻标记间最大间隔为49.0 cM,最小为1.4 cM,平均间隔为13.1 cM.青虾框架图谱长度为997.2 cM,图谱观察总长度为2 270.5cM,根据估算,青虾遗传连锁图谱预期长度为4 380.6 cM,图谱的覆盖率为51.83％.本研究构建了青虾遗传连锁图谱,该图谱也是淡水虾蟹类第一张遗传连锁图谱,可为青虾QTL定位、基因克隆、遗传选育等提供指导,并为进一步构建高密度的青虾遗传连锁图谱奠定了基础.%The oriental river prawn, Macrobrachium nipponense, is widely distributed throughout China, Japan, Korea, and Burma. This species is of economic importance in China where about 209 000 t are produced annually by intensive culture. However, the economic value of the species has declined significantly in recent years due to genetic retrogression. To facilitate genetic improvements, we constructed a genetic linkage map for oriental river prawn using SRAP and SSR markers and pseudo-testcross mapping. A total of 175 makers including 27 microsa-tellite and 148 SRAP makers were mapped in 53 linkage groups. The number of markers per group ranged from 2 to 8 and thirty-five groups included no less than three markers. The average number of markers per group was 3.3. The length of groups ranged from 6.7 cM to 91.2 cM (Kosambi). The maximum space between adjacent markers was 49.0 cM while the minimum space was 1.4 cM, with an average distance between markers of 13.1 cM. The framework map contained 16 groups with a length of 997.2 cM. The total length of the map was 2 270.5 cM. The average estimated genome size for oriental river prawn was 4 380.6 cM. Based on the estimated genome lengths, the map accounted for 51.83% of the genome. This is the first genetic linkage map of oriental river prawn. Our data may be used to aid quantitative trait loci (QTL) mapping, gene cloning, and genetic selection. The map also provides a basis for the construction of a higher density genetic linkage map for oriental river prawn.