甜菜遗传连锁图谱初步构建

Construction of Molecular Genetic Linkage Map of Sugarbeet

以甜菜高产低糖型JV34-2和低产高糖型28023两材料杂交，构建了200个单株的F2作图群体，利用所筛选出的56对SRAP引物组合和20对SSR引物，对F2作图群体进行PCR扩增和遗传连锁分析，初步构建了一张包含9个连锁群、141个（123个SRAP和18个SSR）标记位点的甜菜遗传连锁图谱。该图谱覆盖长度为1399．88cM，平均图距9．92cM。未进入连锁群的有4个标记。9个连锁群包含3～26个标记不等，连锁群遗传距离15．69～237．21cM。连锁群上有20．56％的标记出现偏分离，主要集中在Chr-3连锁群上，其余分散在Chr．1、Chr．2、Chr．8和Chr．9中。该图谱是我国甜菜领域利用SRAP和SSR相结合方法，构建的第一个较精密的分子遗传图谱，为重要性状的基因定位和优良基因的克隆奠定了基础。

Molecular genetic map is a fundamental tool for genomic research. In this study, a molecular genetic map was con- structed using an F2 population consisting of 200 individuals from a cross between sugarbeet JV34-2 （the high beet yield and low sugar content line） and sugarbeet 2B023 （the low beet yield and high sugar content line） and a total of 561 SRAP primers and 114 SSR primers. Approximately 56 out of 561 and 20 out of 114 primers, respectively, showed polymorphisms. Each of these poly- morphic primers produced at least one scorable polymorphic DNA band which was visible enough for detection and scoring. The map consisted of nine linkage groups which included 141 （123 SRAP and 18 SSR） markers, and covered 1399.88 cM with an average distance of 9.92 cM. Three markers were still unlinked. All nine linkage groups consisting of 3-26 markers were 15.69-237.21 cM in length. Twenty point five six percent partially segregated markers distributed in the map, were mainly located on Chr.3 linkage groups, and the others were mapped on Chr.1, Chr.2, Chr.8, and Chr.9. This is the first gene map of sugarbeet, constructed by SRAP and SSR markers in China. It will provide the basis for gene mapping of important characters and cloning of excellent gene in sugarbeet.