Transfer Of A Rye Small Chromosomal Segment With Powdery Mildew-resistant Gene(s) Into Common Wheat

Wheat is one of the most important crops worldwide. In China, wheat is only less important than rice. Powdery mildew, caused by Erysiphe graminisf .sp.tritici, is one of the most seious diseases affecting wheat yield. Developing resistance varieties is the most economical, effective and environmentally safe way to control this disease. However, most of the released varieties had already lost their resistance. Wild relatives of common wheat comprise a large number of resistance genes and are a rich gene source of disease resistance. Of these relatives, rye (Secale cereale L) is the earliest and extensively used alien introgressions in wheat breeding programs. The best approach to make use of the agronomically useful genes in wild relatives of common wheat is to induce translocation. A new approach to produce wheat-rye translocation by using monosomic addition lines as a tool was described by Ren Zhenglong et al. This method can not only induce translocation, but also induce small-segment translocation.Plant breeders frequently wish for very small segments of chromosomes to be introgressed, to minimize the transfer of deleterious genes, It has often proved difficult for breeders to discover and select small-segment translocation. It is necessary to use several methods to identify translocation lines containing the alien chromatin, especially the small-segment-translocation lines. The advanced progeny lines (BC1F5) from the monosomic addition lines between common wheat cultivar Mianyang 11( high susceptible to powdery mildew ) and an inbred rye line R12 were analyzed for wheat-rye translocations. A series of measures, such as A-PAGE, PCR, C-banding and GISH, were taken to detect the rye chromatin contained in the wheat background. Results were shown as follows:...