The Studies On The Species With StH Genomes In Triticeae Based On Biochemical Markers And ITS Sequences

Species of triticeae contains at least 20 essential genes such as Ns, H, P, St, Y, W and E. About 70% of the polyploid species in Triticeae containing the StP, StY, StH, StYW, and StYP genomes.There are about 35 species with the StH genome in the worldwide, which distributed in temperate and warm temperate regions, growthed in the grasslands, valleys, forest, grassland and other marginal environments. In most cases, species with the StH genome are grassland and meadow of fine grass, with high economic and ecological benefits. Due to the characteristics of resistant to cold, drought, salinity, pests and diseases of wheat crop, species containing the StH genome are the important resources for wheat genetic improvement.Species with the StH genome shows geater difference in morphology. They have been classified into different genera, such as Elymus, Hystrix, Sitanion and Elytrigia. Some species also serves as type species of different genera, such as, Elymus sibiricus L.is the type species of the genus Elymus; the type species of Hystrix is Hystrix patula; Sitanion hystrix is the type species of Sitanion, and the type species of Elytrigia is Elytrigia repens.In order to inverstigate the genetic diversity, the interspecific relationships and variation and differentiation in species with the StH genome, glutenin analysis, gliadin analysis and ITS sequences analysis were carried out in the present studies. The main results are as follows:1. Type-rich HMW-GS were present in species with the StH genome and diploid Pseudoroegneria (St genome) and Horduem (H genome) species. A HMW-GS subunits were detected in Pseudoroegneria and Hordeum, respectively. A total of 21 subunit types were detected in 16 species of Elymus (StH). A total of 24 bands were detected in 19 species, but none a band that belonged to all assessions, showed 100% polymorphic. The results showed that great genetic diversity of HMW protein exists among species with the StH genome.2. The gliadin pattern of 31 accessions of species with the StH genome:was analyzed by using acid polyacrylamide gel electrophoresis. A total of 62 bands were detected in all accessions, ranging from 11 to 23 in each accession.100% are polymorphic bands. The Nei's genetic similarity coefficient was ranged from 0.111 to 0.647, and the average Nei's coefficient was 0.379.31 accessions of species with the StH genome was clustered into four groups at GS=0.642 level on the dendrogram. The first group comprised two accession of Et. repens; The second group comprised of two accession of E. tangutorum; The third group comprised of E. wawawaiensis, E. virginicus, H. patula;The fourth group included two subgroup. The first subgroup comprised of E. canadensis, E. lanceolatus, E. caninus, E. trachycaulus, E. glaucus, E. mutabilis. The second subgroup comprised of E. sibiricus,E. confuses, E. transhycanus, E. elymoides, E. multisetus. The results showed that species from the same origin or neighboring geographical regions cluster together, indicating distinct genetic differences and extensive genetic diversity were present among species with the StH genome. The genetic variation between different species was more greater than that of different accessions.3. The nrDNA ITS sequences of the species with StH genome and related diploid species were analysis. In the ML tree inferred from nrDNA ITS sequences, H. patula, E. canadensis, and E. virginicus clustered into one group, which suggested a close relationship existed among these species and supported that H. patula was trested as E. hystrix. E. glaucus,E. wawawaiensis and E. trachycaulus clustered into another group, inferring a close relationship among them. E. caninus and E. lanceolatus grouped together, indicating that they have a close relationship. E. tangutorum and E. mutabilis clustered into one group, which suggested a close relationship between them. Et. repens clustered into one subgroup with P. spicata and P. strigosa, which suggested Pseudoroegneria may be the St genome donor of Et. repens.In the network structure diagram of ITS sequences analysis, accessions of diploid Pseudoroegneria species did not clustered into one group, indicating that genome differentiation occurred in the the St genome. In the H group, there are many mutation sites between H. bogdanii and H. jubatum which distributed in Eurasia and H. chilense which distributed in South America. The results showed that genetic variation occurred in the H genome in Hordeum from different geographical distribution...