| Elytrigia Desv. is important resource plants in gramineae, which have a wide utilization prospect in soil conservation, turf, grassland, and crop breeding. Genetic characters was studied on 15 germpalsm and materials of Elytrigia Desv. under two aspects, Morphological structure anantomy and biochemical analysis. Transverse section of leaves, stems and roots were examined under the scanning electron microscope (SEM), Esterase(EST) isozymes and peroxidase(POD) isozyme were analysed by polyacrylamide gel electrophoresis.1.The observation for morphological structure of Elytrigia Desv. is that: Roots were consisted with epidermis, cortex and stele. The endodermis cell of root have 5 thickened walls, it was horseshoe-shaped in the transverse section. The epidermis of root contains large numbers of root hair. The stem has two circles of vascular bundle and a central pith cavity. The leaf was differentiated into 3 parts: epidermis, mesophyll and veins. In the upper epidermis,the long cells and stomata cells were found in all germplasm and materials. All materials contained the papillae except EE009,EE022,EI021,EI029,EPY002,EC002,EH001 and ES001. The prickle hair existed in all materials except EC002,EE009,EE022,EJ001,EPO004,EPY002. The short cells only existed in EB001,EC002 and EL001. The macrohair was only found in EJ001 and ES001. The microhair was not showed in all materials studied. But in the leaf transverse sections, the bulliform cells were found in the costal zone of all materials, and the bulliform cells in EB001,EH001 and EPY002 materials sank and formed into the"hinge cell". Fibre was distributed in both upper and under sides of the vascular bundle, and joined with it. Vascular bundle sheath was two layers, The cell wall of inner layer was thickened, outer layer was not. It is typical characters of C3 plants.2.There is no significant difference in morphological features of stem and root between different materials. The difference is only on quantity size of parameters. Micromorpholgy of leaf epidermis, was diverse in different species and stable in the same species, have taxonomic value. 3.The Euclidean Distance Cluster Analysis basing on 10 morphological parameters of 15 materials in 12 species Elytrigia was done. The results showed that: Materials of the same species from different countries still have high similarity in morphology.EE009 and EE022 have close genetic relationships, so was ER039 and ER044,EI021 and EI029. 15 materials was divided into 5 groups. The first group include EE009,EE022,EPO004,EH001 and EPY002. The second group, which comprise ER039,ER044,EL001 and EPU002, have relatively far genetic relationship with first group. The third group EI021,EI029,ES001 and EC001was further away from them. EJ001 was further than the third group, EB001 was furthest.4. The results of isozyme analysis showed: The EST zymogram of adult leaves from Elytrigia materials was poor, only have 9 bands. The zymogram of many materials was completely the same. So it not suit to sign the genetic relationship between species. The bands of POD zymogram was plentiful. And the similarity coefficient is relatively lower. The difference between species is significant. 19 materials was divided into 5 groups which have special genetic position. Materials of the same species from different countries have high similarity in POD zymogram. The result is coincident with the result of morphological cluster analysis. So POD zymogram could show genetic relationship of Elytrigia better. |
