小麦异源易位系的高效诱导和分子细胞遗传学鉴定

Efficient Production of Wheat Alien Translocation Lines and Characterization by Molecular Cytogenetics

利用杀配子染色体 (gametocidalchromosome)和低剂量 (10Gy)γ 射线辐射花粉两种方法诱导小麦 (TriticumaestivumL) 滨麦 (LeymusmollisTrin)和小麦 中间偃麦草 [Thinopyrumintermedium(Host)Barkwarth]的易位系。通过基因组原位杂交 (GISH)分析 ,在 5 9个小滨麦代换系M872 4 8 13与离果山羊草 (AegilopstriuncialisL) 3C染色体附加系的杂交后代中获得了 3株小麦 滨麦易位系 ,易位频率达到 5 0 8%。其中 1个易位系经C 分带证明是小麦的 7D染色体与 1条滨麦的染色体发生了整臂易位。同时还获得了 3个滨麦染色体的缺失系。滨麦染色体发生结构变异的总频率为 8 4 7%。除了滨麦染色体以外 ,在一些植株中还观察到小麦的染色体也发生了缺失。在 6 9个普通小麦与小麦 中间偃麦草附加系TAI 14辐射花粉的杂交后代中 ,得到 2株小麦 中间偃麦草的易位系 ,易位频率为 2 90 %。两个易位系都是小片段易位 ,经C 分带证明两个易位系所涉及的小麦染色体分别是 3A和 4A。利用杀配子染色体和低剂量γ射线辐射花粉诱导小麦异源易位系都是行之有效的方法 ,但这两种方法各有优缺点 。

The Triticum aestivum Leymus mollis and T.aestivum Thinopyrum intermedium translocation lines were induced by gametocidal chromosome 3C derived from Aegilops triuncialis and γ ray irradiated pollens of a T.aestivum Th. intermedium addition line TAI 14 with a lower dosage (10Gy),respectively.By genomic in situ hybridization (GISH) analysis,three T.aestivum L.mollis translocation lines (WM 10,WM 43 and WM 47) and three deletion lines (WM 18,WM 43 and WM 44) were selected from 59 F 2 plants derived from a cross combination of T.aestivum L.mollis substitution line M8724 8 13 × T.aestivum Ae.triuncialis 3C chromosome addition line.The frequency of translocation lines produced and total frequency of chromosome structural variation occurred were 5 08% and 8 47%,respectively.Two of the three translocation lines,WM 10 and WM 43 all were heterozygous translocation lines carrying one T.aestivum L.mollis Robertsonian translocation chromosome,but the translocation chromosome in the two lines were different in morphology.The other one,WM 47 was a double heterozygous translocation with two different translocation chromosomes.By the C banding,one of the three translocation lines was identified,the translocation chromosome consisted of 7DL of wheat and a chromosome arm of L.mollis .In addition,wheat chromosome deletions were observed in some plants.In another cross combination involved in common wheat and T.aestivum Th.intermedium addition line,two alien terminal non Robertsonian translocation lines (WI 21 and WI 68) were identified from 69 F 2 plants by C banding and GISH,and the percentage of translocation line was 2 90%.By C banding analysis,the translocation chromosomes involved in wheat chromosomes 3A and 4A in the two lines,respectively.These results indicate that inducing wheat alien translocation line by gametocidal chromosome and irradiated pollens all are efficient methods.