小麦A,B和D基因组同源DNA序列在进化过程中的演变研究

Evolution Study of Wheat (Tritium aestivum L.) A, B and D Genome Based on DNA Sequence Similarity

选取已定位的大麦１Ｈ染色体的ＳＴＳ标记ＭＷＧ ９１３为引物，在普通小麦（Ｔｒｉｔｉｕｍａｅｓｔｉｖｕｍ Ｌ．）及其４个可能的起源种乌拉尔图小麦（Ｔ． ｕｒａｒｔｕ Ｔ．）、栽培一粒小麦（Ｔ．ｍｏｎｏｃｏｃｃｕｍ Ｌ．）栽培二粒小麦（Ｔ． ｄｉｃｏｃｃｕｍ Ｓ．）、方穗山羊草（Ａｅ． ｓｑｕａｒｒｏｓａ Ｌ．）上特异性扩增。扩增产物克隆测序后对其进行序列分析，由序列差异的程度来确定这几个物种之间的亲缘关系。实验结果表明，普通小麦（Ｔｒｉｔｉｕｍ ａｅｓｔｉｖｕｍ Ｌ．）的Ａ基因组此段序列和乌拉尔图小麦（Ｔ． ｕｒａｒｔｕ Ｔ．）、栽培一粒小麦（Ｔ． ｍｏｎｏｃｏｃｃｕｍ Ｌ．）、栽培二粒小麦（Ｔ．ｄｉｃｏｃｃｕｍ Ｓ．）Ａ基因组此段序列完全相同；普通小麦的Ｄ基因组此段序列与方穗山羊草（Ａｅ． ｓｑｕａｒｒｏｓａ Ｌ．）也完全相同；普通小麦的Ｂ基因组此段序列和栽培二粒小麦Ｂ基因组此段序列有０．６１％的差异。研究结果一方面对现有的普通小麦Ａ、Ｂ、Ｄ基因组起源和进化理论给予了分子水平上的证明，同时也揭示了同一物种不同的基因组进化速度存在差异。

Tritium aesrivum L., and its four potential origin species T urartu T., T. monococcum L., Ae.squarrosa L. and T.dicoccum S., were amplified with MWG913, a STS marker located in 1H chromosome of barley. Those products are cloned and sequenced. By the discrepancies of these sequences, we have obtained some evidences about the origin of wheat A, B, D genomes at molecular level. The results showed that the studied sequence in A genomes of Tritium aestivum L. was identical with that of T. urartu T., T monococcum L. and T dicoccum S.; that in D genome of Tritium aestivum L. was as same as that of Ae. squarrosa L.; that in B genome of Tritium aestivum L. differed from that of T. dicoccum S. in 0.61%. The results also suggested that A, B and D genome have the different evolution speed.