Study On Reproductive Allocation Of Four Rhizomatous Grass Populations In Daqingshan Mountain

At present, clonal plant is one of hotspots in biology and Ecology. Rhizomatous grasses (RG) are typical clonal plant which can reproduce new ramet with rhizome and are important vegetation type of grassland on Mongolia plateau, and have two kind of reproduction, including with clonal reproduction and sex reproduction.It is important meanings in biology and aplling foreground for better using the resources of RG to study its reproductive allocation law. In this paper, four kinds of RGs:Leymus chinesis,Leymus secalinus,Agropyron michno and Bromus inermis were studied from the aspect of reproductive allocation at Daqingshan Mountain, which was as a total region, including with biomass ,nutrient elemant and the soluble sugar. The results showed that:1.Vegetative shoots and rhizomes took advantage ratio in population for biomass reproductive allocation of four RGs in the order of vegetative growth>rhizome > reproductive growth. The rate of biomass reproductive allocation in population modulus differed highly with the rates of biomass reproductive allocation in stem of vegetative shoot and rhizome being normally 20%-40%, low rate of reproductive in leaf of sexual shoot being under 5% and lower rate of biomass allocation in ear being under 2%. The rate of biomass allocation in stem from modulus of population sexual shoot was the highest with 30%-50%, the rate of biomass allocation in era was the lowest and under 20% with little difference among populations.2. The allocation rate of the N element in four kinds of RGs for their sexual shoots was the biggest ,almost 50%, sexual growth>vegetative growth>rhizome.The ratio of N in rhizome was as much as 12-13%,and it is similar among populations.The ratio of N among all models are similar to each other. The ratio of N among models in sexual shoot was always 25%, the differences weren't large.Besides, short RGs>long RGs by the ratio of N from leaves and ears of sexual shoots.3. The allocation rate of the P element in four kinds of RGs for their sexual shoots and vegetative shoots was higher, the total ratio was more than 80%,sexual shoots >vegetative,and shoots>rhizomes. The ratio of P in different models were different,but the ratio in ears were highest,the leaves were the second. The ratio of P in eras among models in sexual shoot was the highest, long RGs>short RGs. 4. The allocation rate of the K element in four kinds of RGs for their sexual shoots and vegetative shoots was higher, the total ratio was more than 80%. Sexual shoots were more than vegetative shoots, and rhizome was the lowest.The ratio of K of eras and rhizom was obvious lower than other models.The ratio of P for eras was less than 10%. The ratio of P for eras among models in sexual shoot was obvious lower than other models. Other models were similar to each other.Long RGs>short RGs.5. The allocation rate of the soluble sugar in four kinds of RGs for their sexual shoots and vegetative shoots were much higher, and was almost 70-90%.Upground> underground, and long RGs>short RGs.The ratio of soluble sugar for all models were different. And also were different among four populations.The ratio of soluble sugar for leaves of sexual and vegetative shoots was always lower than stems and rhizoms. The allocation ratio of soluble sugar in four kinds of RGs among their models in sexual shoots was quite different, and also different between two years.