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利用800R剂量60Co-γ射线处理处于减数分裂期的普通小麦-大赖草二体异附加系DA5Lr的大孢子母细胞,开花前去雄套袋,授予普通小麦“中国春”的花粉.对M1种子根尖细胞有丝分裂中期染色体进行GISH分析,得到1株含有2条分别涉及5Lr长臂和短臂的易位染色体植株.将其与二体附加系DA5Lr测交,对测交后代中含有1条5Lr和2条易位染色体植株的花粉母细胞减数分裂行为进行分析,在双线期观察到2条易位染色体和1条5Lr及1条小麦染色体联会成“十”字形构型,中期Ⅰ形成“Z”字形或环状四价体,表明这2条易位染色体为相互易位染色体.染色体C分带结果显示,易位涉及的小麦染色体可能为A组或D组染色体,用pSc119.2和pAs1专化探针分别与其进行染色体荧光原位杂交,易位染色体中的小麦染色体片段上显现出较强的pAs1(对D染色体组专化)杂交信号,根据pAs1标准染色体分子核型,结合C分带结果,易位涉及的小麦染色体为7D,相互易位染色体为T7DS.5LrL/T5LrS.7DL.该相互易位杂合体的配子传递分析表明,2条相互易位染色体常常一起传递,通过雌、雄配子的传递率分别为59.4%和83.9%,表现出花粉优先传递特征.在相互易位杂合体自交后代中,除分离鉴定出相互易位纯合系之外,还获得纯合易位系T7DS.5LrL,该易位系对赤霉病有较好抗性,为小麦赤霉病抗性改良提供了一种新种质.
The megaspore mother cells of DA5Lr, an alien addition line of common wheat-Eupatorium odoratum, were treated with 60Co-γ ray at 800R, and were silage-bagged before flowering and pollen of common wheat “Chinese Spring” GISH analysis of mitotic metaphase chromosomes in M1 seedling root tip cells showed that there were two translocation chromosomes containing two long arms and one short arm in 5Lr, The meiosis of pollen mother cells with one 5Lr and two translocation chromosomes was analyzed. Two translocations and one 5Lr and one wheat chromosome were observed to be " Zig-zag shape or circular tetravalent form in metaphase Ⅰ, indicating that the two translocations are reciprocal translocations.The chromosome C segregation results show that the translocated wheat chromosome may be in group A Or D group, pSC119.2 and pAs1 specific probe were respectively used for chromosome fluorescence in situ hybridization. The chromosome fragment of wheat chromosome in translocation showed strong hybridization signal of pAs1 (specific to D genome) According to pAs1 standard chromosome karyotype, combined with the C banding results , The translocation chromosome involved in translocation was 7D and the translocation chromosome was T7DS.5LrL / T5LrS.7DL.The gamete transfer analysis of the reciprocal translocation heterozygote showed that the two reciprocal translocations were often transmitted together through the female and male gametes Were 59.4% and 83.9%, respectively, which showed the priority of pollen transmission.In addition to the identification of reciprocal translocation homozygous lines, homozygous translocation lines T7DS .5LrL, the translocation line has good resistance to scab, providing a new germplasm for the improvement of wheat scab resistance.