Nitrogen Nutrition Integration Effects On Growth And Photosynthesis Of Two Garden Stem Creeping Weeds

In order to study the influence mechanism of clonal plants through clonal integration on plant growth and photosynthesis in the heterogeneity nutrient habitats, as a constructive basis of clonal plants in landscape application and management. The pot experiment was conducted to simulate the heterogeneity nutrient habitat, to study the effects of nitrogen nutrition integration on Alternanthera philoxeroides Griseb and Herba Glechomae Longitubae’s growth and photosynthesis. Two species’ distal ramets and proximal ramets were placed in different nutritional treatments(Complete nutrient solution、Nitrogen deficiency nutrient solution、Distilled water),and cut off the stolons between distal ramets and proximal ramets or not.The findings are as following:1) Nitrogen nutrition integration exists between two species’ ramets, and stolons remain connected is a necessary condition for nitrogen nutrition integration.2) Nitrogen nutrition integration of two species be with a certain direction, the direction is from proximal ramets to distal ramets.3) Due to the presence of nitrogen nutrition integration, two species’ growth(M、LMA) changed in the heterogeneity nutrient habitat. Specific performance:the proximal ramets in quality nutrition plaques give nutrients to the distal ramets in poor nutrition plaques by the connected stolons, so that to support the distal ramets growth, and reduce the adverse effects of bad nutrition environment brings to the distal ramets’grown.4) Nitrogen nutrition integration of the two species affected its photosynthesis,the photosynthetic parameters(Cc、Pmax、Jmax、Vcmax、 Rd、 PC、PB、 PL、PT) reflected the integration trend similar to the growth in different extent. The best evidence can be seen in Vcmax.5) The nitrogen nutritients of two species given to the distal ramets by the nutrition integration, were more assigned to carboxylation system, thereby enhancing the photosynthesis.6) To contrast the integrated strength of each indexes of two species, found that, two species obtain heterogeneous resources in different ways. Alternanthera philoxeroides Griseb tends to place the growth in superior nutrient plaques, to achieve occupying advantage environment faster; Herba Glechomae Longitubae inclined to counterpoise the ramets’ growth by nitrogen nutrition integration, in order to improve tolerance for heterogeneous nutrient environment.In conclusion, two species affected their photosynthesis by nitrogen nutrition integration, allocated more nitrogen nutritients to carboxylationsystem, improved the ability to fix CO2, so that to enhance the photosynthetic capacity, and support the distal ramets grown in poor nutritional environment, reduce the risk of distal ramets affected by nutrient stress. The change of morphology, which is very important for the two species through different ways to adapt toheterogeneous nutrient environment.