乌拉尔图和栽培一粒小麦抗病基因向普通小麦转移的研究

Transfer of Resistance Genes from Triticum urartu Tum.and Triticum monococcum L.to Triticum aestivum L.

乌拉尔图小麦(T riticum urartu Tum.)和栽培一粒小麦(T riticum m onococcum L.)是普通小麦的两个二倍体野生种,是进行小麦遗传改良的重要遗传资源。为了将其抗白粉病和抗条锈病基因转移到普通小麦中,用普通小麦分别与两份乌拉尔图小麦材料1010013和1010015及一份栽培一粒小麦材料1010048配制杂交组合。结果表明,乌拉尔图小麦与普通小麦杂交不能正常结实,必须进行幼胚拯救,成胚率为14.77%;而栽培一粒小麦与普通小麦杂交可正常结实,但结实率很低。杂种F1自交不育,与普通小麦回交可正常结实,但BC1自交结实率极低。对普通小麦与乌拉尔图小麦杂种F1花粉母细胞减数分裂中期Ⅰ的观察结果表明,平均单价体为17.36个,二价体为5.32个。进一步对杂种后代进行抗病鉴定和遗传分析,乌拉尔图小麦1010013和1010015分别含有一对显性抗白粉病基因,栽培一粒小麦1010048含有两对独立遗传的显性抗条锈病基因,并分别在杂种后代BC2F1和BC1F2中获得了染色体正常(2n=42)、细胞学稳定且抗性与供体亲本一致的抗白粉病和抗条锈病植株,说明来自二倍体乌拉尔图和栽培一粒小麦的抗病基因已通过遗传重组导入到普通小麦中。研究还发现普通小麦莱州953与乌拉尔图小麦和栽培一粒小麦杂交的结实率与中国春的同样高,表明其可能携带有远缘杂交亲和基因。

Triticum urartu and Triticurn monococcum are diploid species of Triticum, which can be useful for wheat improvement. In order to transfer their powdery mildew and stripe rust resistance genes to common wheat, .T. urartu and T. monococcurn （2n= 14, AA） accessions as male were crossed with T. aestivum （2n=42, AABBDD） cultivars/lines. By the contrast with the normal seed set in the crosses of T. aestivurn × T. rnonococcum, the immature embryos of the crosses T. aestivurn × T. urartu must be rescued owing to shriveling of endosperm in hybrid seeds, and the percentage of embryos obtained was 14.77% on the average. Hybrid F1 plants of crosses were sterile, and hybrid seeds could be obtained through backcrossing with T. aestivum, but seed set of intercross in BC1 progenies was very low. Meiotic analysis of F1 PMCs in the crosses T. aestivurn × T. urartu at metaphase I showed 17.36 univalents and 5.32 bivalents on the average. Results of identification of disease resistance and genetic analysis indicated that T. urartu accessions 1010013 and 1010015 carried a dominant powdery mildew gene, respectively, and T. monococcure 1010048 carried two independent dominant stripe rust genes. The derivative lines of BC2F1 and BCF2 which have normal chromosomes and resistant to powdery mildew and stripe rust were obtained, this indieated that the powdery mildew and stripe rust resistance genes originating from T. urartu and T. monococcum accessions were successfully transferred to hexaploid wheat. In addition, it was also found that Laizhou 953 might carry the crossihility gene. Because Laizhou 953 has almost the same seed set as Chinese Spring crossed with T. urartu and T. monococcum.