Genetic Analysis Of Some Germplasm Resources Of Agropyron Gaertn.and Roegneria C.koch.

Total of 39 germplasm materials including five species of Agropyron Gaertn. and seven species of Roegneria C.Koch. were studied in this thesis. Six methods such as morphology, physiology, gliadins, isozyme, ISSR molecular markers and production performance were used on the population samples. The aim of our study was to identify, analyze and make comprehensively research on the above germplasm materials. The results obtained were as follows:1. The materials of two genera were tested in morphology methods existed abundant genetic variation. The variation among species was greater than intraspecific variation. The largest morphological diversity was A.cristatum.var.Pectinforme, A.trachycaulu and R.stricta, the smallest morphological diversity is A.mongolicum and R.dura. There were 8 and 9 characters separately affected the morphological variation of Agropyron Gaertn. and Roegneria C.Koch.. Shannon indexes analysis showed that the morphological diversity among populations was greater than within populations in five species, but morphological diversity within populations was greater than among populations in other five species. The morphological differentiation of R.stricta in the same area was greater than it among the different areas, but the morphological differentiation of other eight species in the same area was smaller than it among the different areas. Euclidean distance clustering results confirmed the scientific traditional classification of two genera once again.2. There were six physiological factors that affected Agropyron Gaertn. and Roegneria C.Koch.leaf physiological and metabolic functions, respectively included MDA content, electrical conductivity, soluble sugar content, relative water content, chlorophyll b, soluble protein content and MDA content, electrical conductivity, proline content, chlorophyll a, relative water content, soluble protein content. From tillering period to spike period and from flowering period to mature period, physiological and metabolic functions of different species were quite different among species, physiological characteristics of different materials of the same species were no significant difference. There were have the strongest physiological ability response to environmentability to A.mongolicum and R.stricta. The related physiological factors respectively affected the yield of Agropyron Gaertn. and Roegneria C.Koch. were soluble protein content and electrical conductivity, relative water content.3. Gliadin was polymorphic. The polymorphisms percentage were 89.19% and 92.50% in Agropyron Gaertn. and Roegneria C.Koch.. The genetic diversity among species was greater than intraspecific in Agropyron Gaertn., but smaller than it in Roegneria C.Koch.. Genetic parameters analysis showed that A.cristatum and R.dura had the largest genetic diversity, A.trachycaulu and R.melanthera had the smallest genetic diversity; The gliadin bands of different populations of A.trachycaulu and R.melanthera had no significant difference; The genetic differentiation of R.nutans in the same area was greater than it among different areas, and the genetic differentiation of other five species in the same area is smaller than it among different areas.4. The bands of peroxidase and esterase had the significant difference. The polymorphism rates are 90.00% and 100.00% in Agropyron Gaertn. and Roegneria C.Koch..The polymorphism of peroxidase is greater than EST in Agropyron Gaertn., but Roegneria C.Koch. had the opposite traits. Genetic parameters analysis showed that genetic diversity among species was greater than it within species. And the maximum genetic diversity index was in A.cristatum and R.nutans, the minimum genetic diversity index is in A.trachycaulu and R.turezaninovii var. turczaninovii; The isozyme bands of different population of A.trachycaulu and R.melanthera had no significant difference; The genetic differentiation of R.turezaninovii var. turczaninovii in the same area is greater than it among different areas, and the genetic differentiation of other five species in the same area is smaller than it among different areas.5. Genetic diversity was rich. There were 83 and 177 polymorphic bands were detected respectively from 7 and 21 random primers in Agropyron Gaertn. and Roegneria C.Koch., which were tested by ISSR markers, and the polymorphism rates respectively were 94.32% and 92.17%. Genetic parameters analysis showed that Agropyron Gaertn. genetic diversity among species was greater than it within species, but Roegneria C.Koch. had the opposite traits; A.mongolicum and R.nutans have the maximum genetic diversity index, but A.cristatum. var. pectinforme and R.melanthera. had the minimum genetic diversity index. The genetic differentiation of five species in the same area is smaller than it among different areas.6. Production performance was significant difference. A.trachycaulu and R.stricta. had the best production performance. The gray correlation analysis showed that there were 11 and 9 agronomic traits closely related with the yield of Agropyron Gaertn. and Roegneria C.Koch.. The yield of grass was generally high, but seed yield was generally low. The seed yield of Agropyron Gaertn. was significantly higher than Roegneria C.Koch.. A.mongolicum and R.stricta had the highest grass yield, A.cristatum and R.turezaninovii var. turczaninovii had the highest seed yield, but A.cristatum. var. pectinforme and R.nutans. had the lowest grass yield and seed yield. Because different species had so different growth rate from spike period to flowering period, it was the optimal time to identify and evaluate the species at that time. Clustering results could not fully reflect genetic relationship of different kinds of species in two genera, but it could reveal the difference of their production performance.7. Clustering results showed that the same species of Agropyron Gaertn. could gather essentially within species and clustering conditions was related with geographical origin. The materials of the same species of Roegneria C.Koch. could not gathered within species, as the same as nutans germplasm and straight spike germplasm, but a small part of the material showed geographic clustering homology. The clustering results were consistent, which of morphology, physiology, protein and DNA molecules obtained, but production performance had different clustering results. Correlation analysis showed that the correlations among genetic diversity, parameters and ecological factors had not significant difference at different markers level.8. The genetic relationship and evolution among species analysis suggested that A.derstorum maybe a derivative species of A.cristatum and A.monogolicum, and A.cristatum. var. pectinforme was a variant of A.cristatum; It was concluded that R.nutans and R.dura which was belong to little glume group were in the original state, but R.turezaninovii var. turczaninovii which was belong to long glume group were in the evolution state.9. According to Mantel test results, it will be better to identify and evaluate the germplasm of Agropyron Gaertn. by some methods such as morphology, physiology, gliadin, ISSR markers and production performance. Use morphology, gliadin and ISSR marker methods to identify and evaluate the germplasm of Roegneria C.Koch. can also get good results. Isozyme identification still needs to be studied in the future.