大白菜紫心性状遗传规律分析及其基因初步定位

以大白菜Brassica rapa(Lour.)ssp.pekinensis]紫心纯系‘14S839’和橙色纯系‘14S162’为亲本,构建F_2群体,对大白菜紫色基因(BrPur)进行遗传连锁分析。性状分离调查结果显示,在F_2群体中紫心与非紫心单株符合3︰1分离比例,说明大白菜紫心性状的有、无符合单基因显性遗传模式,紫心性状是一种显性性状。采用改良的BSA方法对紫色基因BrPur进行定位,经过对白菜全基因组297个SSR标记的筛选,得到了BrPur的两个侧翼标记A710和A714,同时结合白菜基因组信息,将BrPur定位于大白菜A07连锁群上。结合前人关于花青素代谢相关基因的研究报道,通过分析Br4CL3和Bra004214的序列、开发新的标记,得到了两个特异共显性标记CL-12和B214-87。利用F_2群体扩增验证筛选到的所有标记,结果表明,经Join Map 4.0作图得到的遗传连锁图与非紫色交换单株"基因型矩阵"显示的结果完全一致,标记CL-12和B214-87位于BrPur两侧,遗传距离分别是3.1 cM和3.5 cM。

Genetic Analysis and Primary Mapping of the Purple Gene in Purple Heading Chinese Cabbage

To analyze genetic linkage and map the location of purple gene（BrPur）controlling purple inner leaves trait of Chinese cabbage，a F₂ population constructed by the single-plant-selfing of F₁ hybridized from homozygous purple heading line‘14S839’and homozygous orange heading line‘14S162’was used. The field investigation of head color shows that the separation proportion of purple heading individuals to non-purple heading individuals fitted to the ratio of 3︰1 in F₂ population，which means that the purple heading of Chinese cabbage was a dominant phenotype and consistent with genetic pattern of a single dominant gene. Then，two flanking linkage markers，A710 and A714，were obtained by a modified BSA method with 297 SSRs in whole genome，and the BrPur was primarily mapped on linkage group A07 based on the location of the two flanking markers sequence in BRAD. Subsequently，two novel flanking markers，CL-12 and B214-87，were developed by cloning and homology sequence alignment analysis of Br4CL3 and Bra004214 involved in anthocyanin related genes in previous reports. Finally，we verified the linkage relationship of all markers using F₂ population，and found that their genetic map obtained by Join Map 4.0 was consistent with the result from Plant Genotype Matrix of all non-purple crossover individuals，which placed CL-12 and B214-87 flanking two side of BrPur locus at genetic distances of 3.1 cM and 3.5 cM，respectively.