Development And Identification Of Wheat-rye5R Translocation Lines

Rye (Secale cereale) is an important genes donor for wheat (Triticum aestivum)improvement. The using of crossbreeding techniques could help to import rye excellentgene into wheat, improve the yield and resistant of wheat, promote the production ofwheat, and broaden the base of wheat breeding. Currently, the reports of excellentresistance gene on rye5R chromosome are less, needs further study. In this study, usingthe gametocidal chromosome, obtained the progeny of the hybrids of Chinese Spring-Aegilops column2C addition lines (2n=44AABBDD+2Câ…¡, CS-2C) containingGametocidal chromosome and wheat-rye5R/5A substitution line (2n=42AABBDD+5Râ…¡-5Aâ…¡,5R/5A). the progeny were analyzed by morphological, molecular markers,cytological, genomic in situ hybridization (genome in situhybridiza tion) and othertechnical means. Wheat-rye5R translocation lines with high resistance to powderymildew were selected. The results summarized in the following:1. The seed set of the two groups of contemporary hybrid of5R/5A and CS-2C wasdifferent.BC1F1were obtained through the backcross of F1and5R/5A and F2wereobtained through the self-cross of F1. There was difference on seed set between BC1F1and F2. The spike type of F1generation is the intermediate type of parent5R/5A andCS-2C. The panicle type separation occurred in the F2and F3plants. There are somechromosomal aberrations in the chromosomes of progeny, the number of chromosomesin somatic cell changed from40to43, chromosome structural variation includedtelomere, circular chromosome and dicentric chromosome.2. The powdery mildew resistance of parents and progeny was identified,5R/5Aand progeny with5R chromosome (short arm) showed higher resistance to powderymildew, which suggested that there is a powdery mildew resistance gene on the shortarm of rye chromosome5R and the resistance gene was transferred into the wheatgenome and effective.3. The progeny was identified with rye specific primers PSC20H by PCR, thepositive rate of F1generation was100%,38positive plants were obtained from80progeny, the positive rate of F2generation was47.50%,24positive plants were obtainedfrom80progeny, the positive rate of F3generation was30.00%. Two pairs of5RS specific PCR markers primers were designed in this study, which were located atproximal portion and pericentromeric region of5RS. these two pairs of primers couldbe used to identify progeny plants containing the chromosomes of rye5RS.4. The F2, F3, F4plants with PCR-positive bands were identified by GISH,10translocation lines, including seven5RS homozygous translocation lines: W13-19,W13-29, W13-46, W14-9, W14-30, W14-48, W14-68, three5RS heterozygoustranslocation lines: W13-20, W13-21, W13-26, and three introgression lines: W13-23,W13-77, W13-78were obtained in this study.