Study On Shade Tolerance Of Some Main Shrub Species Used In Harbin

Based on the natural investigation,through the allocated observing under natural condition and the analysis on the inside experiment,with the methodology of anatomy and physiology,this paper emphersized on systematic research on Harbin local 7shrubs (conducing Prunus triloba LindK Primus tomentosa Thunb Sorbaria sorbitolia(L) A.Br. Cornus stolonifera. -,Syringa oblata Lindl.,Syringa reticulata Hara var mands Hara huriea -. Philadelphus schrenkii Rupr).The content of the chlorophyll (a+b),the chlorophyll a and the chlorophyll b,the leaf structure (concluding palisade mesophyle thickness .epidermal mesophyle thickness and leaf thickness) and photosynthetic light response curves (including the light compensated,the light saturation point and the photosynthesis rate of light saturation) of 7 shrubs were studied systematically. Through analysis ,a resolution is acquired:1. The ratio of leaf thickness of palisade mesophyll or epidermal mesophyll in 7 shrubs' leaf structure,in shinning leaf is clearly higher than that of shading leaf.2. The palisade mesophyll thickness in Prunus tomentosa Thunb,Syringa oblata Lindl. Sorbaria sorbitolia(L) A.Br. and Syringa reticulata Hara var mands Hara huriea is much thicker. While the Epidermal mesophyll thickness in Philadelphus schrenkii Rupr Cornus stolonifera. is rather flourishing.3. Different photosynthetic light conditions have much influence on the content of chlorophyll in 7 shrubs and leaf structure,and according to the difference of the ability of photosynthesis,the content of Chlorophyll and leaf structure changed markedly.4. There is a trend,the content of chlorophyll (a+b ) ,and chlorophyll(b) in shading leaf are lower than in shinning leaf of 7 shrubs.5. In 7 shrubs,the chlorophyll (a+b) of Philadelphus schrenkii Rupr and Syringa reticulata Hara var mands Hara huriea. is high,but the chlorophyll a/b of them is lower;the chlorophyll (a+b) in Sorbaria sorbitolia(L) A.Br. is not the highest and Chlorophyll content is lower,while,the chlorophyll b is relatively higher;the chlorophyll a/b of Cornus stolonifera. Prunus tomentosa Thunb,Syringa oblata Lindl. and Prunus triloba Lindl is all higher and Chlorophyll b/(a+b) is lower.6. Photosynthetic light response curves in 7 shrubs shows:to Prunus triloba Lindl and Syringa oblata Lindl. the light saturation point,the light compensated point and the photosynthesis rate of light saturation are all high;while to Philadelphus schrenkii Rupr and Sorbaria sorbitolia(L) A.Br.,they are lower;to Syringa reticulata Hara var mands Hara huriea,the light compensated point is lower,but the light saturation point is moderate and the photosynthesis rate of light saturation is higher.7. Comparing 7 shrubs roundly :Prunws triloba Lindl and Syringa oblata Lindl. havehigher synthetic efficiency to strong light followed by Cornus stolonifera. and Prunus tomentosa Thunb. ,however,Philadelphus schrenkii Rupr and Sorbaria sorbitolia(L) A.Br. have higher synthetic efficiency to weak light;Syringa reticulata Hara var mands Hara huriea has certainly adaptability to strong light and weak light.To sum up,the factors that influence shade-tolerance of plants are complex.Only with a multiple analysis on the data of the content of the chlorophyll,the leaf structure and photosynthetic light response curves ,an objective and comparative research on the shade-tolerance of 7 shrubs was conveyed.