二倍体蔷薇FT基因序列多样性研究

以3个类群73个二倍体蔷薇属(Rosa)植物为材料,克隆获得其FLOWERING LOCUS T(FT)同源基因,并对该基因的编码区序列进行多态性分析以及多维尺度(MDS)聚类分析。结果显示,73个二倍体蔷薇植物的FT基因共检测到215个核苷酸多态性位点,其中包括214个SNP和1个缺失突变,平均185个碱基发生1次突变;氨基酸多态性分析结果显示共有35个氨基酸发生变异,平均379.6个氨基酸残基发生1次突变;突变位点统计分析结果发现39、258、426 bp位点是高频突变位点,其碱基由A或C突变为T。MDS聚类分析结果表明,3个类群FT基因编码区序列的碱基组内差异依次排序为:野生种月季组中国古老月季,氨基酸组内差异依次排序为:中国古老月季月季组野生种,推测中国古老月季在长期栽培驯化过程中,其FT基因可能经历了较强的人工选择压力,月季组的种和变种可能是古老月季的重要亲本来源。

Sequence diversity of the FT gene in diploid Rosa

To understand the polymorphism of the FLOWERING LOCUS T(FT) homologous gene in Rosa and its relationship between different rose germplasm types, we cloned the FT homologous genes from 73 diploid Rosa germplasms. The sequence polymorphisms of the FT genes were analyzed using multidimensional scaling(MDS) cluster visualization. In total, 215 nucleotide polymorphism loci were detected in 73 diploid materials, including 214 SNPs and one deletion locus, with an average of 185 bases and one mutation. For amino acid polymorphism, a total of 35 amino acid mutations were detected, with an average of 379.6 amino acids and one mutation. Statistical analysis of the mutation sites showed that the 39, 258, and 426 bp sites were high-frequency mutation sites, and the bases were A or C mutated to T. The MDS cluster visualization analysis results indicated that the differences in the base mutations of the FT gene coding region of the three taxa were wild species > Sect. Chinenses DC. > Chinese old garden roses, and the amino acid variance within groups was Chinese old garden roses > Sect. Chinenses DC. > wild species. Thus, we speculated that during the long-term cultivation and domestication of the Chinese old garden rose, the FT genes experienced strong artificial selection pressure. We further identified close genetic similarity among the Sect. Chinenses DC., wild species, and Chinese old garden roses. However, the genetic relationship between wild species and Sect. Chinenses DC. was further apart. This indicates that Sect. Chinenses DC. may be an important parent of the Chinese old garden roses.