Effects Of Cellular Metabolism And Wood Structure Of Betulla Platphilla By Drought Stress

In this paper cell, metabolism and wood formation in seedings of Birch under water stresswere studied. The results as follwing:Cell metabolism of Birch by fertilizer and the control has been affected under water stress.Leaf relative water content, leaf relative conductivity, soluble protein content, the netphotosynthetic rate and POD activity changed significantly, stomatal conductance, water useefficiency, AsA-POD activity and activity of GR changed significantly.Control and fertilizationtreatments only appear significant differences in soluble sugar content, The more soluble sugarin the leaves of plants under water stress to maintain osmotic potential and cell metabolism. Byanalyzing the correlation between various indicators and soil moisture, the physiologicaladaptability of fertilizer plant to water stress is better than the control. Therefore, thefertilization treatment Birch seedlings have the stronger drought tolerance capacity contrast tothe control.Being observed the slices of wood sticks and trunk sections through the microscope andwood scanning analysis, the formation of White Birch wood was affected by Water Deficit andfertilizer. The rate of cell wall of non-fertilization control branchlet was smaller than that of thefertilized in threatening initial stage, but bigger in the mid and late of the threatening stage. Inthe early and late, the proportion of fiber of the non-fertilization control was bigger than that offertilization birch branchlet, and that of fertilization birch branchlet was bigger in the mid. Thetransformation of the proportion of vessel of birch seedlings' branchlet was answer to waterstress. The proportion of vessel of the non-fertilization control was bigger in the mid, whichcould have the ability to meet short-term drought; and that of fertilization birch branchlet wasbigger in the late, which was able to adapt to a longer period of drought. The rate of cell wall ofnon-fertilization control trunk was bigger than that of fertilization birch trunk, but smaller inthe proportion of fiber. In addition, the pseudo-annual rings were found in small sticks, whichmay be related to the decline and death of pareuchyma. It was also found that the rate of woodcell wall was decreased in fertilization under water stress, but also the axial parenchyma wasincreased, so that the hardness of wood would be reduced.