Molecular And Cytogenetics Identification Of Wheat Alien Chromosome Lines Derived From Thinopyrum Intermedium Ssp. Trichophorum

As a wild relative species of wheat, Thinopyrum intermedium (2n=6x=42，JJJsJsStSt) has high ability to propagate, which contains a wealth of good genes, and iswidely used in wheat genetics and breeding. Thinopyrum intermedium not only has highprotein content, and also has excellent features of cold tolerance, drought tolerance, salttolerance, rust immunity(leaf rust, stripe rust, stem rust) and powdery mildew resistance,yellow dwarf disease resistance, By using distant hybridization and chromosomeengineering, the useful genes from Thinopyrum intermedium were successfullytransferred to wheat and greatly improve the quality and yield of globle wheat,therefore.Th.intermedium ssp. Trichophorum is a subspecies of Thinopyrumintermediumretained many superior genes. The aim of this study is to analysis andidentification of the cross progenies materials between wheat line MY11and wheat-Th.intermedium ssp. trichophorumis partial amphiploid by the methods of morphologycytology, molecular biology and biochemistry. New resistant addition lines X484-3andsubstitution lines X479and X482were identified.1. Characterization of X484-3addition line: Chromosome numbers in root-tipcells of X484-3were2n=44, and resistant for the stripe rust at adult plant stage.Previously established molecular markers of PLUG primers from homologous group1to7were used to amplify CS, X484-3, MY11, TE-1508, Thinopyrum intermediumandPseudoroegneria spicata. Compared with the polymorphic bands of tested lines,wefound that both X484-3amplified St specific band which consistent with the St specificbands of Thinopyrum intermedium and Pseudoroegneria spicata.This suggest thatX484-3has a pair of St chromosomes which belongs to homologous group7. FISHwith St probe, revealed the introduced St chromosomes. Therefore, X484-3is a new7Stadditional lines with stripe rust resistance.2. Characterization of substitution lines X479,X482: Using molecular markers,seed protein SDS-PAGE analysis and in situ hybridization. At series materials of X479 (479-1-1,479-2-1,479-2-2,479-2-3,479-3-1,479-3-2,479-3-3,479-3-4)andX482(482-1-2,482-1-3,482-2-2,482-2-3,482-3-1,482-3-2,482-3-3,482-4-1,482-4-3)were identified. PCR-based molecular markers from homologous group1and4analysisindicated that X479lack of both chromosomes1B bands and4B specific bands, butintroduced St specific bands of homoeologous group1and Js specific bands ofhomologous group4. Gliadin and glutelin analysis showed the lack of B genomespecific protein band.Moreover, FISH by the B genome specific probes PHVG38and Dgenome specific probes pAs1, also shows1B and4B chromosomes were absent inX479. PCR amplification of X482, revealed the lack of chromosomes4D and6Dspecific bands analyzed by using molecular markers from homologous group4and6.However the Js specific bands of homoeologous group4and St specific bands ofhomologous group6were found in X482.The FISH by D genome specific probes pAs1also demonstrated X482was lack of chromosomes4D and6D. Chromosome numbersof X479and X482displayed high resistant to stripe rust. Therefore, X479was a1St (1B)+4Js(4B) double substitution lines, while X482was a6St (6D)+4Js(4D) doublesubstitution lines.In summary, the new type of wheat-Thinopyrum genetic resources identified bymolecular cytogenetic methods,will be important value to wheat genetics and breeding.