Transfer And Identification Of Thinopyron Intermedium Resistant Gene To Powdwry Mildew

In the progenies of common wheat Yannong15×Thinopyron. intermedium, cytogenetics and molecular cytogenetics methods combined with resistance identification to powdery mildew were used to transfer the resistant gene to powdery mildew of Thinopyton intermedium. Results were obtained as below.l.In the BC₁F₅ and BC₃F₄ generation of YannonglS Thinopyron intermedium hybrid, 4 octoploids which had chromosome number of 2n=56 and could form 28 bivalent at PMC MI, 14 disomic addition lines which had chromosome number of 2n=44 and could form 22 bivalent at PMC MI; three monosomic addition lines which had chromosome number 2n=43 and had the chromosome configuration of 21 II+1 I at PMC MI ,1 substitution line which had chromosome number 2n=42 and could form 21 bivalent at PMC MI were selected by observation of mitosis in root tip cell and meiosis in pollen mother cell. One octoploid 990256, four disomic addition lines E99006, E99009, E99010, E99015-8 and one substitution line E99018 resistant to powdery mildew were selected by identification of artificial induced powdery mildew disease.2. Biochemical identification showed that the octoploid 990256 probably had different alien chromosomes compared with the octoploids zhongl, zhong2, zhongS, zhong4 and zhong5 created by cross between common wheat and Thinopyron intermedium. In situ hybridization identification using wheat genomic DNA, Pseudoregnaria stipifolia genomic DNA and Th.elongatum genomic DNA as probeindicated that the octoploid 990256 perhaps added a mixed genome comprise of 10 J chromosomes and 4 E chromosomes at the base of common wheat YannonglS.3.In situ hybridization using Pseudoregnaria stipifolia and Th.elongatum genomic DNA as probe indicated that the four addition lines were all added a pair of E genome chromosomes of Th. Intermedium. The substitution line E99018 was substituted a pair of wheat chromosomes by the same alien chromosomes. Analysis of resistance segregation and chromosome number in the F2 population using the resistant addition lines to cross with four susceptible varieties showed that the resistant gene located on the alien chromosome of Th. intermedium. 30 identification hosts having known powdery mildew resistance genes and 21 differential isolates of E. graminis f. sp. Tritici were used to test the infection response of resistance to powdery mildew in octoploid 990256 and addition line E99006.The infection response in 990256 and E99006 were different from the known powdery mildew resistant genes used, which indicated furthermore that a pair of chromosomes of E genome comes from Th. Intermedium conferring a new resistant gene to powdery mildew, probably.4.The ph Ib gene mutation of common wheat Chinese spring was used to cross with the resistant addition line E99009.Chromosome configuration of F| at PMC MI was observed, and backcross was conducted using the phlb mutation. In the progenies of backcross, chromosome configuration combined with resistance identification was conducted, the single plants with high chromosome mating frequency and high resistance to powdery mildew were selected to self to select translocation line in the selfing progenies. One translocation line G026-4 was selected by resistance identification and in situ hybridization.There were other materials to be identified.5. The addition lines conferring 3C gametecidal chromosome of Ae. Triancialis was also used to induce translocation lines. They were crossed with addition line E99006, E99009, E99010, respectively. The meiosis process of FI were observed, much more univalents or chromosome fragment were found at PMC MI and many lagging chromosomes or chromosome fragments at PMC AI, A II were found. Muchmicronucleoli also appeared in trerad of the three combinations. In the F2, F3 generation of the combination E99006/gameteadal addition line, cytology identification combined with disease identification was conduct to select translocation lines. One translocation line G007-1-10 and one substitution line GOI 1-1 were selected, and there were also...