通过HRM技术筛查与梨矮生性状决定位点PcDw紧密连锁的SNP标记

在果树的基因组中存在大量的SNP（single nucleotide polymorphism）位点，筛查与目标性状紧密连锁的SNP标记，对目标基因的精细定位具有重要意义。以‘矮生梨’（Pyrus communis L.‘Aishengli’）与‘茌梨’（Pyrus bretschneideri Rehd.‘Chili’）的F1杂交分离群体共215个单株为试材，参考苹果基因组的序列设计26对适合HRM分析的引物，依据分离群体分组分析（bulked segregant analysis，BSA）原理，通过高通量熔解曲线（high resolution melting，HRM）分析，筛选到两个与决定梨矮生性状的PcDw基因连锁的标记CNqau012和CNqau039，二者与目标位点的连锁距离分别是13.3 cM和2.3 cM。对CNqau012和CNqau039的扩增子测序分析表明，在矮生型与普通型中都存在一处单核苷酸变化（分别是G/A和C/T）。这些标记的获得对PcDw基因的精细定位及克隆具有重要意义。

Screening of SNP Markers Tightly Linked to PcDw Locus Determining Pear Dwarf Trait Using HRM Technology

Screening of SNP markers tightly linked to objective traits is critical for fine mapping of objective gene due to abundant SNP loci exist in the genome of fruits. In this research，26 primer pairs which are suit for high resolution melting（HRM）analysis were designed according to the sequences from apple genome. Based on the principle of the bulked segregant analysis（BSA），these primer pairs were tested in the F1 population with 215 individuals derived from the cross of Pyrus communis L.‘Aishengli’× Pyrus bretschneideri Rehd.‘Chili’by HRM，and two markers（CNqau012 and CNqau039）linked to PcDw locus at the distance of 13.3 cM and 2.33 cM，respectively，were identified. Furthermore，the amplicons of the two markers（CNqau012 and CNqau039）were sequenced and one single nucleotide changes（G/A and C/T，respectively）between the dwarf and standard phenotypes were detected. These SNP markers are of great significance to the following fine mapping and cloning of the PcDw gene.