小麦TaFT基因编码区序列多态性及其与开花期的关系

Polymorphism of Wheat TaFT Gene Expressional Sequence and the Impact to Flowering Dates

春化基因VRN-B3是小麦开花素基因TaFT,为探索该基因在品种间的保守性及其与小麦开花早晚的关系,根据TaFT基因序列(GenBank accession No.:DQ890162)设计特异PCR引物,扩增了13个品种中该基因的编码区。通过测序和序列比对,发现不同品种间该基因编码区的DNA序列存在多态性,序列翻译发现5个品种的表达产物FT蛋白发生变异。利用中国春的非整倍体材料将TaFT基因定位在7BS染色体上。参考品种的冬春性及开花时间,推测冬性品种正常的FT蛋白(同DQ890162翻译的氨基酸序列一致)可加速开花,FT蛋白变异则延迟开花;春性品种的FT蛋白变异与否对开花期影响不大,推测TaFT基因的效应可能被春性品种的显性春化基因所掩盖。

It has been confirmed that the wheat vernalization gene VRN3 is an orthologue of FT. In this study, special PCR primers were designed using the software‘DNAMAN＇ based on the sequences of TaFT （GenBank No. DQ890162）. The PCR products amplified from 13 cultivars with different flowering dates were sequenced from two directions. Sequence alignment was conducted using the software BioEdit. The results of DNA sequence polymorphism showed that the translational FT protein from five cultivars had mutations. The TaFT gene was mapped to chromosome 7BS using a set of nulli-tetrasomic lines and ditelosomic line 7BL of Chinese Spring. According to the vernalization characteristics and the flowering time we deduced that for the winter cultivars, the normal FT protein may accelerate flowering, the FT protein mutation will delay flowering; for the spring cultivars, the dominant vernalization allele genes may substitute the TaFT gene＇s function, and FT protein variation will not obviously influence flowering dates.