Change Of Physiological And Biochemical Characteristics Of Tetrastigmatis Hemsleyani Diels Et Gilg Under Different Light Intensities

Tetrastigmatis hemsleyani Diels et Gilg,Vitaceae,Albertisia Becc,is a rare and precious Chinese herbal medicine,which lives cool and moist environment and medicinal value is very high.In order to investigate the influence of T.hemsleyani Diels et Gilg growth characteristics in the light intensity stress,with biennial cutting seedlings as test materials,the effects of different light intensities?the full light,shading rate of 30%,50%,70%and 90%?on photosynthetic characteristics,spectral characteristics and relevant physiological index were studied.The results were as follows.?1?T.hemsleyani Diels et Gilg growth suffer from photoinhibition in the shade under 30%,and produced stomatal inhibition phenomena.Growing well in the shade above 50%,growing best in the shade of 70%,and did not produce stomatal inhibition phenomenon.The main reason is the shading enhances the photosynthetic activity of mesophyll cells of T.hemsleyani Diels et Gilg,which make Pn rise.A certain degree of shading can increase chlorophyll content,LSP,LCP,Gs and Tr and reduce Rd.It is helpful to improve the photosynthetic efficiency of T.hemsleyani Diels et Gilg.?2?The spectral reflectance of T.hemsleyani Diels et Gilg leaf had significant differences in the visible region?400 nm⁷00 nm?under different light intensity.Pigment content of T.hemsleyani Diels et Gilg leaf was negatively correlated with reflectance in 400nm⁷40 nm wavelength range,but it was positively correlated with reflectance in750 nm¹000 nm wavelength range.With the decrease of the light intensity,?red were increased,and the"red shift"phenomenon appeared.With the light intensity decreased,the related spectral parameters of chlorophyll,carotenoid and anthocyanin were increased in general,the vast majority of parameters in the shade of 50%,70%and 90%were significantly,and reached the maximum in the 70%shading treatment.Spectral parameters mSR₇₀₅,PSSRb,PRI,Sblue can be used to monitor the chlorophyll content of T.hemsleyani Diels et Gilg leaf under different light intensity stress.?3?With the decrease of light intensity,the content of soluble protein,free proline and SOD were first decreased and then increased in the T.hemsleyani Diels et Gilg leaf,which were highest in the full light treatment and lowest in the 70%shading treatment,and the difference wassignificant.?4?The all growth index of T.hemsleyani Diels et Gilg were the best in the 70%shading treatment.The content of total flavonoids in the T.hemsleyani Diels et Gilg leaf and roots appeared a synergistic and inverse synergistic phenomenon with the net photosynthetic rate.With the decrease of light intensity,the content of total flavonoids in the leaf of T.hemsleyani Diels et Gilg was first increase and then decrease rendering denticular,but the overall trend was contrary in roots.The content of total flavonoids was highest in the leaf in the 30%shading treatment,while the highest in the roots was in the control group.The average content of total flavonoids in roots was slightly higher than that in leaf,but the difference was not significant.