| In the tribe Triticeae, the P genomic plants mainly includes all of species in Agropyron Gaertn. (P genome) and Kengyilia Yen et J. L Yang (StPY) or Roegneria Sect. Paragropyron Keng. These species have important roles in forage grasses and ecological equilibrium, and possess potentially valuable traits for wheat and other cereals improvement, such as tolerance to drought, low temperature, salinity and resistance to some diseases including rusts, head scab and others. So, genetic diversity and phylogenesis research of these species were paid more attention by researchers. Total of 250 populations include 136 populations in A. cristatum (L.) Gaertn.﹑21 populations of A. desertorum (Fisch ex Link) Schult.﹑15 populatioms of A. fragile (Roth) Candargy﹑46 populations of A. mongolicum Keng ﹑4 populations of A. michnoi Roshev. ﹑26 populations of 11 species in the genus Kengyilia Yen et Yang and 2 populations of Roegneria angustiglumis , all of them were kept in the National Center For Crop Germplasm Conservation of Chinese Academy of Agricultural Science, were studied to their genetic diversity and phylogenesis. Some results as follows:1,Evidence from GISH indicated that all examined 11 species in genus Kengyilia Yen et J. L. Yang had the StPY genomic constitution. Among these species K. laxistachya and K. shawanensis were firstly attested to having the StPY genomic constitution.2,Three types of translocations (namely simple translocation, reciprocal translocation in long arm and reciprocal translocation in short arm) involving P-genome chromosomes were firstly revealed in 5 populations of K. longiglumis, K. grandiglumis and K. shawanensis. These would give new views to P genome' genetic positions in the tribe Triticeae. 3,Roegneria angustiglumis had the same StPY genomes. According genomic constitutions of new genus Kengyilia Yen et J. L. Yang, Roegneria angustiglumis should be included in the genus Kengyilia also.4,The gliadin banding pattern with 8 level of bulked seed samples of 22 populations of 5 species in Agropyron Gaertn. was analyzed. When bulked seed samples surpassed 12 (included 12) seeds, the gliadin banding patterns was relatively uniform. So, bulked seed samples above 12 could be choose to represent whole population to view genetic diversity of gliadin.5,In the morphological level, the biggest change was spike width in morphological characterizations in populations of 5 species in Agropyron Gaertn.. The mean of spike width's coefficient of variation was 24.670. The second change was spike segment length. Its coefficient of variation was 16.840. The smallest change was stem height, which coefficient of variation was 13.490. According total of morphological characterization variables in population among Agropyron Gaertn., the change of Agropyron michnoi was the biggest. 6,In the gliadin level, different areas accessions had different gliadin diversity. Inner mongolicum﹑Xinjiang and Qinghai populations had higher gliadin diversity than other original populations in A. cristatum. Their simpson index were 0.927﹑0.922 and 0.920 respectively. The areas of Yuling and Inner mongolia had higher genetic diversity in A. mongolicum. Their simpson index was 0.910 and 0.906 respectively. The genetic variation found among different areas was 4.6% (average) and among species was 5.3%, that is, 95.4% of the total of genetic diversity was in areas, and 94.7% was in specie, respectively.7,In DNA level, The genetic variation found among different areas bigger (14.5% in A. cristatum and 16.2% in A. desertorum) than among genus (10.7%) and among species (10.1%). So, the original situation was more nearly, the genetic distance was more closely between populations and the UPGMA clustered more closely. The most genetic diversity (90.9%) was found within populations in A. cristatum. The genetic diversity of different area was Xinjiang 0.735＞Inner mongolia 0.714＞the northeast China 0.678＞Gansu 0.677＞Shanxi 0.599＞Shaanxi 0.562＞Qinghai 0.553. The genetic distance analysis suggested A. derstoru... |
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