Study On Conservation Biology Of The Endangered Plant Myricaria Laxiflora (Franch.) P.Y. Zhang Et Y.J. Zhang

Myricaria laxiflora (Franch.) P. Y. Zhang et Y. J. Zhang belongs to Myricaria Desv of Tamaricaceae,is the perennial shrubs, rare and endangered endemic plants in Three Gorges reservoir area,has strong tolerance to submergence, is a good species for slope protection, the shore protection, maintaining water and soil and the important officinal plants and ideal foliage plants.Mainly distributed in the Three Gorges reservoir area of 70-155 m above water-level-fluctuating zone. With the completion of the Three Gorges Project, the new water-level-fluctuating zone is forming, then the original habitats of M. laxiflora were submerged all.So,it is important to study on conservation biology especialy salvage technical research.Base on the survey of five populations of M. laxiflora in the Three-Gorge reservoir area,with the helps of statistical software named SPSS,we studied the morphological differentiation of 50 individuals from 5 populations and the relations between morphological differentiation and the soil factors,and did the research of cutting propagation and stress resistance, with a view to finding the best cutting conditions and cultivation conditions, providing a theory and practice basis for ex situ conservation. The results show that:1) For The single-factor (one-way) variance analysis of the 24 morphologocal characters of the five populations showed that:4 characters are significant, and 5 characters(all are genital organ) are extremely significant. On the whole, the morphological differention of M. laxiflora is obvious, explained that its morphological characteristics are great impacted by habitats, particularly genital organ, individuals in all forms divergence.2) Cluster analysis showed that: on the individual level , all the individual in popullations 1 and opulations 2 good polymerize in the A-11.0 characterization group and a-6.0, b-6.0, c-6.0 characteprization sub-groups.It shows that populations 1 and 2 have high shape similarity and close relations between the two populations. From the population level of cluster analysis shows that populations 1 and 2, populations 3 and 4 got together firstly , means that among these two groups there is a greater similarity of shape, and the result is same to the level of individual cluster analysis. At the same time, the Euclidean Distance of individuals or populations is more than 0,shows that the species has a genetic heterogeneity.3) The relationship of the soil factors and the morphological differentiation analysis result indicated: The soil factor has a greater impact to the M. laxiflora's morphological differentiation,and its effection to reproductive organ is bigger than that to the shape organ. In brief, some soil factor possibly plays the leading role to some morphological differentiation, but it is impossible to take the absolute control effect to all characters, therefore the M. laxiflora's external features differentiation is combined action result of various soil factors.4)The cutting propagation technology research showed that: when the IBA concentration is 50 mg / L, the rate of rooting is highest,because concentration of IBA too high or too low will inhibit the cuttings' root growing. The illumination and stromata also have an important impact on the growth, the most suitable for M. laxiflora cutting growth is a layer of shade, 1 loess and 1 sand. The effection of shading treatment to the cutting growth is higher than that of IBA concentration .5) The resistance research indicated:In PEG simulated drought stress, with the extending and strengthening of drought stress, the MDA and proline content increase gradually;the protein content, SOD, POD activity rise after gradual declining;flavonoid content increase with the strengthening of stress. In waterring stress, the MDA, protein content increase after the first dropping with the the extending and strengthening of stress, the greater intensity of stress, the bigger rate of decline; SOD activity, POD activity and proiine content increased after the first declining and then increase gradually. Flavonoids in the semi-submerged processing is similar to that in the basal-submerged processing and CK, but the flavonoids content significantly increase in wholly submerged processing.