A Comparative Study On Drought Resistante Of Physiologicai Characteristics In Three Cupressaceae Varieties

The research of drought resistance under PEG-6000osmotic stress on three years cypress plants of Sabina vulgaris Ant. Sabina chinensis (L.) Ant. and Juniperus formosana’Blue Arrow’is in the Institute of Pomology and Forestry Beijing Academy of Agriculture and Forestry Sciences. By comparing the3Cupressaceae plant seedling leaf anatomical structure and the leaf relative water content, relative electric conductivity, MDA content, SOD activity, free proline, soluble sugar and soluble protein content under osmotic stress,we sduty the drought resistance of3cupressaceae varieties.Through the research and analysis above, it will provide reference in the selection of water-saving landscaping plant. The main results showed as following:1. The anatomical structure of3varieties of plants is similar, but dissimilar parameters of tissue structure. The cuticle thickness, thickness of leaves and cortical thickness of different varieties have significant distinction. The drought resistant ability sequence of the3varieties of plants from the strong arrive the weak support Sabina vulgaris Ant.> Sabina chinensis(L.) Ant.> Juniperus formosana’Blue Arrow’one by one in order.2. We emulate osmotic stress in laboratory, with Polyethylene Glycol (PEG-6000) concentration of increase, RWC of3varieties of plants relative are reduced continuously, Juniperus formosana’Blue Arrow’is the largest decline, which shows that water-holding capacity is not strong, and Sabina chinensis (L.) Ant. and Sabina vulgaris Ant. drops slowly.3. The relative electric conductivity and MDA content of3varieties of plants under drought stress increased with the concentration. The electric conductivity and MDA content of Juniperus formosana’Blue Arrow’increased most, followed by Sabina chinensis (L.) Ant., the smallest is Sabina vulgaris Ant. The activity of SOD of Sabina vulgaris Ant. increases with the increasing stress concentration and time increasing, Sabina chinensis (L.) Ant.and Juniperus formosana’Blue Arrow’decreased.4. The contents of soluble sugar and proline,which are related to osmotic adjustment ability, appeared the same changes trend, increasing gradually, the content of soluble protein changes are different among different varieties.5. The appearance anatomic parameters and physiological index of3varieties was comprehensive evaluation respectively by fuzzy subordination method, the result is consistent. The drought resistance of3varieties of landscape plant from high to low order:Sabina vulgaris Ant.> Sabina chinensis (L.) Ant.> Juniperus formosana’Blue Arrow’.The results of test and the external morphological characteristics in the period of the test were basically the same.