Herbaceous Plant Selection And Introduction Of Bayan Obo And Research Of Cold Resistance And Drought Tolerance

Bayan Obo area of Inner Mongolia has massive vegetation destructed by mining. Because the climate is extremely arid and cold, natural conditions are so bad that the desertification is much more serious. This subject invested the plant species of the surrounding environment and then made the current environment conditions to the main contradiction. This subject has introduction of herbs plant including 34 species. From early May 2010 until the end of July, introductions of Hemerocallis x hybird,Sedum spectabile,Jerusalem artichoke,Potentilla fruticosa etc totaling 12 species are survived. From the determination of plant height, maximum canopy widths, leaf size, yield per plant leaf number and growing, Jerusalem artichoke,Hemerocallis x hybird,Pennisetum alopecuroides,Lotus corniculatus,Potentilla fruticosa,Dianthus amurensis,Medicago sativa grew faster and better.Drought tolerant experiments mainly include two parts:Determinate the diurnal variation of photosynthesis on July 31,2010 on Bayan Obo of Coreopsis grandiflora,Saussurea japonic,Helianthus tuberosus,Malva sylvestris,Adenophora remotiflora,Hemerocallis x hybird,Dianthus chinensis,a then record the Pn,Tr,Cond,Ci of mature leaves, And analyse plant drought resistance from the physiological characteristics.In conclusion, which have a better drought resistance, are Malva sylvestris and Saussurea japonica, Pn are 31.4μmolCO2m-2s-1 and 24.4μmolCO2m-2s-1,WUE are 7.61mmol CO2m-2s-1 and 5.19mmolCO2m-2s-1.The worst is Adenophora remotiflora.Pn is only 5.6μmol CO2m-2s-1.In late July 2010, the author makes the basin control and drought stress experiments on Coreopsis grandiflora,Tradescantia albiflora,Saussurea japonica,Potentilla fruticosa,Helianthus tuberosus,Hemerocallis x hybird,Medicago sativa,Adenophora remotiflora. Having observed the wilting process of plants, according to the measuring device blade Pn (Net Photosynthetic Rate), Cond (Stomatal Conductance), Tr (Transpiration rate), WUE (WUE=Pn/Tr), Membrane relative permeability, and the relative water content (RWC) of leaves, the author summarizes that Saussurea japonica,Adenophora remotiflora are more sensitive to the stress, the conductivity of the sixth day are 81.68% and 79.98%. And then is the Helianthus tuberosus and Medicago sativa, while Tradescantia albiflora,Hemerocallis x hybird,Potentilla fruticosa are not sentitive since the color of leaves hardly changes and have resisted the drought for a longer time,their conductivity are still keep to 87.9%,77.4%,73.5%. JinLouMei stress of the net photosynthetic rate still rising 10.67μmolCO2m-2s-1, while the remaining plants are declined.These indexes can be taken for measuring the drought resistance of plants and the analysis is consistent with the actual observation. The sequences of drought resistance of the 8 plants are as below:Hemerocallis x hybird,Tradescantia albiflora,Potentilla fruticosa are stronger, then are the Helianthus tuberosus,Medicago sativa,Coreopsis grandiflora and Saussureajaponica,Adenophora remotiflora are the last ones.In the experiment of cold-tolerance, based on the analysis of conductivity, the soluble protein, MDA and the soluble sugar, the author finds out that conductivity, soluble protein and the soluble sugar can truly reflect the cold-tolerance of plants but the MDA is not. On half a lethal temperature, Dianthus chinensis is the lowest when it has 20.87 mg/g of soluble protein and soluble sugar increased 1.3 times after stress.But the soluble protein of Malva sylvestris continue to decline to 6.41 mg/g.According to the experients, the sequence of cold-tolerance of the five plants is:Dianthus chinensis>Medicago sativa>Potentilla fruticosa>Coreopsis grandiflora>Malva sylvestris...