Molecular Cytogenetic Analysis Of Wheat-elytrigia Elongata Hybrids And Identification Of Trititrigia Germplasms

Elytrigia elongata (Host) Nevisk.[Syn. Thinopyrum ponticum (Podp.) Barkworth](2n=10x=70) was determined to have many agronomical useful traits for wheat improvement,such as high protein, tolerance to salt and drought, resistance to stripe rust, leaf rust, Fusariumhead blight and wheat streak mosaic virus.These genes have been transferred into wheat andextensively used in improved resistance to various pests and tolerance to abiotic stresses.Inthe present study, identified and analysed by methods of morphology, cytology, biochemistryand molecular biology, analyze the genome composition and configuration of wheat-E.elongata hybrids plants; identified Trititrigia alien chromosome lines from progenies betweenE. elongata and Triticum aestivum; and molecular marker analysis powdery mildew resistancegene. The main results were as follows:1. GISH was conducted using St-genomic DNA from Pseudoregnaria strigosa as theprobe determined that5types chromosome composition was of E. elongata was exhibited. By4560pairs of SSR markers and1200RAPD markers analyze E. elongata, Agropyronelongatum (Ee), Thinopyrum Bessarabicum (Eb) and Ps. strigosa (St). The sesults indicate thatEe、Eband St had a close genetic relationship, and were basic chromosome complement of E.elongata. The genomic formulas for E. elongata were StStEeEbEx.2. By methods of morphology andmolecular cytogenetics, analyze the genomecomposition and configuration of wheat-E. elongata F1、F2、BC1F1、BC1F2and BC2F1hybridsplants. To discuss the characteristics of chromosome separation in different hybrid generationsand affect of chromosome segregation with different pattern of crossing.3. By methods of morphology and cytology,17Trititrigia alien chromosome lines wereidentified from progenies between E. elongata and Triticum aestivum, including3octoploid Trititrigia (SN19、SN20and SN122),11introgression lines (87074-513、-526、-541、-551、-554、-555、-557、-565、-576、NX22and NX28), and3translocation line (NX5、NX24andNX25).4. Genomic in situ hybridization (GISH) and fluorescence in situ hybridization (FISH)were used to establish the genomic constitutions of the19Trititrigia alien chromosome lines.Octoploid Trititrigia SN19has54chromosomes and other partial amphiploids have56chromosomes. SN19and XY7430both had intact wheat genome chromosomes plus12E.elongata chromosomes, SN20and SN122both had14chromosomes from E. elongata,XY693has16chromosomes from E. elongata, and their constitutions of alien chromosomeswere:2"St+4"Ee、1"St+4"Ee+1"Eb、1"St+5"Ee+1"Eb、1"St+4"Ee+2"Eband4"Ee+4"Eb. NX5、NX24and NX25were3translocation line and their translocation chromosomewas1BS. Probing of other14Trititrigia alien chromosome lines with pAsl and pHvG38revealed that their chromosome structure were different with their wheat parents.5. SN0224, derived from crosses between E. elongata and common wheat Yannong15,was analyzed with cytological procedures, genomic in situ hybridization, powdery mildewresistance screening and molecular marker analysis.A single dominant Pm gene, derived fromE. elongata and temporarily designated as PmSn0224, was found on the wheat chromosome2A of SN0224. Based on data from205F2plants of SN0224/Huixianhong, the resistance genewas linked to three polymorphic microsatellite markers Barc212, Xwmc522and Xbarc1138with genetic distances of5.1,5.3and7.0cM.