Response Of Tissue Culture Seedlings Of Atractylodes Lancea(Thunb.) DC To Soil Physical And Chemical Properties Of Alluvial Island

Atractylodes lancea（Thunb.）DC.is an authentic Chinese medicinal material of Maoshan in Zhenjiang.With the rapid increase in market demand for the wild resources and intensive mining,the resources of A.lancea are almost extinct and are listed as one of the four endangered medicinal plants in Jiangsu Province.In order to efficiently protect the germplasm resources of A.lancea,people tried to cultivate it artificially and establish planting base of A.lancea.However,due to the rapid development of our country’s economy,the agricultural land resources are becoming scarce,and new agricultural land resources are urgently needed to be developed.The use of alluvial islands in the middle and lower reaches of the Yangtze River,which have a similar climate to that of the geo-authentic area,and the promote planting on a large amount of nutrient-poor soil have important theoretical and practical significance for the protection of A.lancea germplasm resources and island wetland ecosystems.In order to solve the problems such as the difficulty of seedling acclimatization,and the poor compatibility between seedlings and alluvial island soil environment,this study took the Shiyezhou as an example,investigated the plant electrophysiological parameters,photosynthesis,chlorophyll fluorescence and growth indicators,determined the characteristics of leaf water transport and its influence on the photosynthesis and growth of A.lancea,combined with the investigation of the soil physical and chemical properties of Maoshan and Shiyezhou,a large number of high-quality tissue culture seedlings were provided in a short period of time through the rational allocation of seedling acclimatization substrate and nutrient solution,and vinegar lees organic fertilizer and nutrient solution were added to the soil of Shiyezhou,which improved the growth of A.lancea.A method of adaptive cultivation of A.lancea in the soil of Shiyezhou could be explored.The results show as follows:（1）Compared with Maoshan soil,Shiyezhou soil had lower nutrient element content,with significant difference,and the water was ineffective and dissipated quickly,which was easy to cause the shortage of water in the root system,increase the inherent transport resistance(C_R0),so water transport was inhibited,and affected the absorption of nutrient elements,resulted in significantly lower net photosynthetic rate（P_N）,plant height,leaf number and total leaf area increased slowly.A.lancea was not adaptive to the soil of Shiyezhou,the weak water retention capacity and low nutrition were the main limiting factors for the growth of A.lancea in the soil of Shiyezhou.（2）The rooted A.lancea tissue cultured seedlings were transplanted into different substrates for acclimatization.The T1 substrate（vermiculite:perlite=1:1）has weak water holding capacity and low nutrient supply capacity.Although the survival rate was relatively high,the seedlings grew worse in the later stage.A small amount of peat soil was added to the T2 substrate（vermiculite:perlite:peat soil=1:1:1）to increase the nutrients appropriately,but meanwhile the moisture content in the substrate became too high,which was not conducive to the survival of the tissue culture seedlings.The moisture content in the T3 substrate（vermiculite:perlite:peat soil=1:1:2）was too high,but the peat soil with a high proportion provided sufficient nutrients for the growth of tissue cultured seedlings.30 days after the seedlings were refined,the maximal photochemical efficiency（F_v/F_m）,electron transfer rate（ETR）and other chlorophyll fluorescence indexes,P_N,plant height,maximum leaf area and number of leaves of A.lancea tissue cultured seedlings in this treatment were higher than those of other treatments.（3）By reducing the irrigation frequency during the acclimazitation period,the moisture content in the acclimatization substrate was reduced.The addition of different concentrations of chitosan oligosaccharides（COS）to the applied 1/2MS nutrient solution effectively reduced the C_R0 of the tissue culture seedlings and improved the adaptability of the tissue cultured seedlings to the substrate.By difference analysis（P≤0.05）,the P_N,water use efficiency（WUE）,photosynthetic pigment content,total leaf area and number of leaves per plant reached the highest value when the COS concentration was 100mg·L^-1.The optimal improved nutrient solution was 100mg·L^-1COS+1/2MS.（4）The capillary porosity,aeration porosity,electrical conductivity and nutrient content of Shiyezhou soil increased significantly with increasing of vinegar lees organic fertilizer supply rate,while p H and bulk density decreased significantly.The P_N,chlorophyll content,chlorophyll fluorescence and other related indexes of A.lancea leaves reached the highest value when organic fertilizer concentration was 30g·kg^-1.The best concentration of organic fertilizer was 30g·kg^-1.If higher organic fertilizer concentration was applied,the above indexes of A.lancea were reduced.During the 30 days of transplanting,4 times of nutrient solution was irrigated,and P_N,photosynthetic pigment content and growth status of A.lancea were significantly better than those treated with no nutrient solution.The C_R0 of A.lancea leaves decreased due to the applied of vinegar residue organic fertilizer and improved nutrient solution.Based on the detection of plant electrophysiological parameters,a new method for rapid diagnosis of plant water status can be established,which provides a guarantee for the exploration and rapid establishment of adaptive cultivation methods of A.lancea.