| Wheat is one of the most important food crop in China and even in the world. The short arm of 1B in wheat replaced by the short arm of 1R formed the 1BL.1RS wheat-rye translocation. As the 1BL.1RS wheat-rye translocation chromosome carries many useful genes, the 1BL.1RS translocation has been used extensively for improving yield traits in wheat breeding program.In this study we choose CN17, CN12, CN18 which obtain 1BL.1RS translocation chromosome and wheat cultivar Mianyangll(wild type for stay-green), Chian spring and rye as the research materials. Meanwhile we use CN17 and MY 11 as parent materials to creat the F2, F3, F4 populations.We analyze the chromosomal locating of the EST sequences related with leaf senescence in 1BL.1RS wheat-rye translocation and the frequency of 1BL.1RS chromosome translocated. The main results were summarized as follows:1.32 previously identified ESTs during the delaying leaf senescence stage in a stay green wheat cultivar CN17 were mapped 42 chromosomes, chloroplast, mitochondrion, and ribosome by silicon mapping. Following, we developed 19 pairs of primers based on the sequence of them, which were employed to determine the polymorphism between stay green cultivars (CN12, CN17, and CN18) and the control cultivar MY11, China Spring,rye.5 out of 19 pairs of primer produced polymorphism between stay green cultivar and the non-stay green control.2. Further studies by Chinese Spring nullisomic-tetrasomic showed that JK738991 was mapped on 3B, and JK738983 was mapped on 5D, and JK738989 was mapped on 2A,4A, and 3D. The other two ESTs JK738994 and JK739003 cannot be assigned any a chromosome by Chinese Spring nullisomic-tetrasomic, and this implied that they might be derived from rye DNA in the wide cross. The linkage analysis among JK738994, JK739003, and 1BL.1RS translocated chromosome using the F2 lines derived from MY11/CN17 were executed, and the results showed that JK738994, JK739003, and 1BL.1RS translocated chromosome were independent assortment each other.3. For the purpose of discriminating the 1BL.1RS translocation for wheat qualitu improvement, a total of 6 STS markers specific to 1BL.1RS translocation were employed to detect all the individuals. Most of them can stably amplify, and have clear bands on electrophoresis gell.But the specific band of some individuals appeared absent or multiply. It was proved that the marker loci on IRS existence stably in most wheat background. But in a few individuals there are certain variation of molecular marker loci.4. In the 3 generations, the reciprocal crosses heterozygous proportion is less than the theoretical value of 50%, translocation lines homozygous for the proportion of chromosomal translocations contain less than the proportion of homozygotes and 25% less than the theoretical value, without translocation chromosome containing more than 25% homozygotes. After x2 analysis, segregation ratio have deviated from the 1:2:1. Based on this result, we conclude that, in this experiment, the crosses 1BL.1RS chromosome translocation in the transfer process, the selection of male and female gametes occurred.5. Chromosome translocation in orthogonal frequency transmission combination three generations were:68.4%,63.8%,66.4%; anti-crosses as follows:62.3%,63.7%, 65.7%. Reciprocal crosses showed the opposite trend, while the reciprocal cross orthogonal decreased gradually increased, but still higher than the anti-orthogonal cross. By the above data, we can see different female in this experiment, seriously affecting the genetic nucleus chromosomes. Thus speculated 1BL.1RS cytoplasmic translocation lines in wheat genome, there must be a stable translocation chromosome gene transfer. |
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