Effect Of Environmental Factors On The Photosynthetic Characteristic And Growth Of Acanthopanax Senticosus Seedings

Acanthopanax Senticosus is not only the important Chinese medicinal resources, but alsoan important component of forest resources, which plays an important role in maintainingecological balance. For that Acanthopanax Senticosus has wide pharmacological functions,wild Acanthopanax Senticosus were dug massively, which caused annual decrease of resource.In order to protect and rationally develop and utilize Acanthopanax Senticosus, make theresource sustained utilized, in last ten years, it had been propagated and cultivated artificiallyin large areas. However, people lack the understanding of the variation of photosyntheticphysiological characteristics, when the environment changes. The effect of environmentalfactors such as soil moisture, nitrogen and light intensity on the photosynthesis, physiologicalcharacteristic and growth of Acanthopanax Senticosus seedlings were investigated, adaptivestrategy to environmental factors were revealed, In order to offer scientific base for gaininghigh yield when people artificially plant Acanthopanax Senticosus seedlings in the future.(1)The ability of photosynthesis of Acanthopanax Senticosus seedlings decreased, butwater use efficiency increased as the water stress degree was increased. In group of T1, theseedlings of Acanthopanax Senticosus did not differ from CK in net photosynthesis rate andwas in high level, in group T2 and T3, the photosynthetic rate of Acanthopanax Senticosusseedlings differed from CK in net photosynthesis rate and was in low level.Content of photosynthetic pigment of Acanthopanax Senticosus seedlings decreased as thewater stress degree increased, group T3 had the lowest content of photosynthetic pigment thanCK. The proline contents in Acanthopanax Senticosus seedlings under mild water treatmentswere significantly higher than those in the control, the MDA contents in moderate water stressand severe water stress drought treatment arrived at the highest.The biomass of Acanthopanax Senticosus seedlings was the greatest under mild watertreatment than other treatments and began to decline along with the degree of droughtenhancement.(2)With an increase of nitrogen supply, photosynthesis in the seedlings of Ac, anthopanaxSenticosus were increased significantly, at 8mmol·L^-1 nitrogen levels, AcanthopanaxSenticosus seedlings had the strongest photosynthesis and highest net photosynthesis rate. Atlower nitrogen levels (1 and 4 mmol·L^-1), the photosynthesis was restrained ofAcanthopanax Senticosus seedlings.Content of photosynthetic pigment of Acanthopanax Senticosus seedlings increased as thenitrogen supply was increased, Additional nitrogen supply significant increased content of leafnitrogen and protein in Acanthopanax Senticosus, seedlings, but content of leaf phosphorus was decreased.Deficient nitrogen supply significant restrain growth,biomass accumulation andallocation of Acanthopanax Senticosus seedling, at 8mmol·L^-1 nitrogen levels, AcanthopanaxSenticosus seedlings had the optimum growth status.(3)Optimum shading can increase photosynthetic ability, the photosynthesis of moderateshading of Acanthopanax Senticosus seedlings arrived at the highest.The content of chlorophyll and carotenoids increased ensuing from the weakness of lightintensity and the ratios a/b of chlorophyll decrease along with the weakness of light intensity.Content of soluble sugar decreased as the light intensity was increased, the content of starchand protein of moderate shading increased the highest level.The growing conditions of moderate shading of Acanthopanax Senticosus seedlingsarrived at the best and decreased with the order of the intensity of the cotrol and severe shading.The biomass reduced ensuing from the weakness of light intensity.