Comparison On Structures And Growth Characters Of Modules In Experimental Elymus Excelsus Population In Different Growing Years On The Songnen Plains

Elymus excelsus is a tufted perennial herbaceous species of Gramineae. It is better palatability to feed animals, and it is suitable to be cultivated in light and intermediate salinization soil in arid and semiarid regions. The quantity character, the tiller structure, the dormancy module structure, the reproductive allocation and the relationship between clone modules and the size of E. excelsus clone planted in different years (2005, 2006 and 2007) of the experimental E. excelsus populations were studied at the level of clone and module on the Songnen Plain of China. And the relationships between the quantity characteristics of reproductive tillers of different growing years and quantity attributes were also analysed to discover the growth characters and rules of E. excelsus population of different living year. The conclusions below could be obtained from the field samples and lab measures as well as statistic analysis:E. excelsus has two dormancy types, one is winterness seedling with lotiform tuft and the other is winterness buds. The number and biomass of E. excelsus clones in different growing years showed the same rules, those were : the number of vegetative tiller > the number of reproductive number; the number of winterness buds > the number of winterness seedlings; the biomass of reproductive tillers > the biomass of vegetative tillers.At different growth stages, the variation of E. excelsus spike biomass was the highest compared with the reproductive tiller height, the spike length, the tiller biomass, the reproductive growth ratio and the reproductive allocation in different years. Among these, the coefficient of variation (CV) of spike biomass at the flowering period of reproductive tillers planted in 2006 reached 54.59 %, the CV of spike biomass at the heading period planted in 2007 reached 78.91 %. With the increase of growing years, the reproductive allocation (RA) and the ability of sexual reproduction of E. excelsus decreased gradually, while the coefficient of variation (CV) increased gradually.The positive correlations between the number of reproductive tiller and its biomass, the number of vegetative tillers and its biomass, the number of tillers and the biomass with tuft diameter of the E. excelsus clone planted in 2005 and 2006, respectively, were not significant (P>0.05). There was a significant (P <0.05) or extremely significant (P <0.01) positive power correlation between the number of reproductive tiller, the number of vegetative tiller, the total number of tiller and tuft diameter, respectively. In three planted years, the correlations between the clone dormancy module, the number of the winterness seedlings and the number of the winterness buds with the tuft diameter of E. excelsus clone were not significant, indicating that there was no significant correlation between the dormancy module and the clone size.Among the correlations between the spike length and tiller height, the tiller biomass and its height, the spike biomass and the tiller height, the spike length and the tiller biomass, the spike biomass and the tiller biomass, the reproductive growth ratio and the spike length, the reproductive growth rate and the tiller height, the reproductive allocation and the tiller height at different growth periods and in different years of E. excelsus, those who showed significances were mainly power and linear, exponential took second place, indicating the plasticity of matter and energy allocation in reproductive tillers of E. excelsus clone.