Molecular linkage map construction and mapping genes for useful traits in Asiatic hybrid lily

为了解亚洲百合（2n=24）花被片花色素和花斑形成这两个花色素性状的遗传背景，以96个亚洲百合品种“蒙特勒”和“康涅狄格王”杂交F_1代植株为材料，研究了这两个性状的分离。“蒙特勒”花被片中有花青素色素沉着，有许多斑点，“康涅狄格王”花有类胡萝卜素色素沉着，没有斑点。F_1代花被片中有花色素苷的植株与无花色素苷的植株分离比例为1：1，表明花色素苷的形成受单基因控制。每平方厘米花被片上的斑点数在F_1植株中呈连续分布。为定位亚洲百合花色素苷色素性状的基因座，以亚洲百合F_1为材料，利用212个PCR标记，采用双重拟测交策略构建了亚洲百合花色素苷色素性状的分子连锁图谱。花被片中花青苷色素沉着的性状被用作性状标记。“蒙特勒”的连锁图谱包含95个标记，分布在26个连锁群中，“康特勒克斯”的连锁图谱包含119个标记，分布在24个连锁群中。图谱总长度分别为867.5和1114.8cM。花色素苷在花被片中的遗传位点位于连锁群1的标记ASR 35 -180和P506-40之间，图距分别为1.2cM和2.6cM。对花被片斑点数量的QTL进行单点分析，在‘康涅狄格王’连锁群1和19中发现了两个QTL。连锁群19中的一个QTL解释了总表型变异的64%。由于这两个QTL都定位在无斑点的‘康涅狄格王’连锁图上，因此它们的显性等位基因可能抑制斑点的形成。

To understand the genetic background of two floral anthocyanin pigmentation traits, anthocyanin pigmentation in the flower tepals and spot formation, in the Asiatic hybrid lily (2n=24), segregation of the two traits among 96 F_1 plants derived from a cross between commercial cultivars 'Montreux' and 'Connecticut King' were investigated. 'Montreux' has anthocyanin pigmentation in the tepals with many spots, and 'Connecticut King' has flowers with carotenoid pigmentation without spots. The F_1 plants with or without anthocyanin pigment in the tepals segregated with a 1 : 1 segregation ratio, indicating that a single gene controls anthocyanin pigmentation in the tepals. The number of spots per square centimeter of all tepals showed continuous distribution in the F_1 plants. To map the loci for the two anthocyanin pigmentation traits, molecular linkage maps in the Asiatic hybrid lily were constructed using a double pseudo-testcross strategy with the same F_1 plants used for phenotypic evaluation and 212 PCR-based DNA markers. The trait for anthocyanin pigmentation in tepals was used as a trait marker. The map of 'Montreux' comprised 95 markers in 26 linkage groups, and the map of 'Connecticut King' used 119 markers in 24 linkage groups. The total map lengths were 867.5 and 1114.8 cM, respectively. The trait locus for anthocyanin pigmentation in the tepals was between markers ASR35-180 and P506-40 in linkage group 1 of the 'Montreux' map with map distance 1.2 cM and 2.6 cM, respectively. A single point analysis of quantitative trait loci (QTL) for tepal spot number identified two putative QTLs in linkage groups 1 and 19 of the 'Connecticut King' map. One putative QTL in the linkage group 19 explained 64 % of the total phenotypic variation. Because both putative QTLs were mapped on the linkage map of 'Connecticut King' that has no spots, dominant alleles of them might suppress spot formation.