High-resolution mapping of the bolting gene B of sugar beet
High-resolution mapping of the bolting gene B of sugar beet
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DOI：
10.1007/s00122-001-0859-z
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发表时间：
2002-07-01
影响因子：
5.4
通讯作者：
Jung, C
中科院分区：
文献类型：
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作者：
El-Mezawy, A;Dreyer, F;Jung, C
甜菜（Beta vulgaris L.）是一个二年生物种。芽伸长（抽薹）在低温一段时间后开始。位点B的显性等位基因导致不经冷处理的早抽薹。这种等位基因在野生甜菜中很丰富，而栽培甜菜携带隐性等位基因。15个AFLP标记，紧密连锁的抽薹位点，已确定使用混合分离分析。F-2群体由单个F-1植物（Bb）自交后衍生的2，134个个体组成。第一步，利用249个标记构建了一张连锁图谱，覆盖范围为822.3cM。这些位点分布在9个连锁群上，对应于Beta物种的单倍体染色体数目。17个标记位点被放置在距离小于3.2厘米左右的抽薹基因。在第二步中，将与B最紧密连锁的那些标记中的四个与整个F-2群体作图。两个标记被定位在B基因的侧翼，距离为0.14和0.23 cM。另外两个标记定位在距离该基因0.5cM处。通过对88株不相关植株的检测，可以验证这种紧密连锁。紧密连锁的标记将使育种者能够选择非抽薹性状而无需费力的测试杂交。此外，这些标记被用于图位克隆的抽薹基因。
Sugar beet (Beta vulgaris L.) is a biennial species. Shoot elongation (bolting) starts after a period of low temperature. The dominant allele of locus B causes early bolting without cold treatment. This allele is abundant in wild beets whereas cultivated beets carry the recessive allele. Fifteen AFLP markers, tightly linked to the bolting locus, have been identified using bulked segregant analysis. The F-2-population consisted of 2,134 individuals derived after selfing a single F-1-plant (Bb). In a first step, a linkage map was established with 249 markers based on 775 F-2-individuals with a coverage of 822.3 cM. The loci are dispersed over nine linkage groups corresponding to the haploid chromosome number of Beta species. Seventeen marker loci were placed at a distance less than 3.2 cM around the bolting gene. In a second step, four of those markers most closely linked to B were mapped with the entire F-2-population. Two of the markers were mapped flanking the B gene at distances of 0.14 and 0.23 cM. The other two markers were mapped at a distance of 0.5 cM from the gene. The tight linkage could be verified by testing 88 unrelated plants from a breeding program. The closely linked markers will enable breeders to select for the non-bolting character without laborious test crossings. Moreover, these markers are being used for map-based cloning of the bolting gene.