Growth And Physiological Characteristics Of Machilus Chinensis And Its Effects On Mycorrhizal Inoculation

The genus Machilus?Lauraceae?,mainly distributed in tropical and subtropical regions of South-Eastern Asia continent,is an important component of the subtropical evergreen broad-leaved forest.It is also an important resource for medicine,chemical industry and horticulture.However the serious destruction of the wild resources and lacking of breeding,species in Machilus are the lack of proven and systematic cultivation techniques to breed up in nature.In this study,I analyzed the growth law,fertilization,seedling resistance and mycorrhizal colonised seedlings?growth mechanism of M.chinensis by the pot test method.The aim of this study was to provide a theoretical basis for the further study on M.chinensis propagation techniques,as well as to provide scientific basis for developing the cultivation techniques and understanding the growth physiology of Machilus.The main results are summarized as follows,?1?The effects of nitrogen fertilizer,phosphate fertilizer,potash fertilizer and compound fertilizer on the growth and rhythm of M.chinensis were analyzed.The nitrogen fertilizer,phosphate fertilizer and compound fertilizer improved the growth and biomass accumulation in different degrees,but potash fertilizer inhibited the seedling growth and biomass accumulation.Fertilization treatment increased the laminaarea,leaf number and chlorophyll amount to a certain extent.The growth and the diameter of seedling are in accordance with the characteristics of Von Bertalanffy curve,the coefficients of determination?R²?of each fitting equation are more than 0.990,and the chi-square values X² are far less than X²_0.05,indicating that the fitting equation reaches a significant level and a high degree of fitness.According to the characteristic parameters of the curve equation,it can be seen that adding nitrogen fertilizer and phosphate fertilizer advanced the timing of fast seedling growth,but the effect of compound fertilizer and potash fertilizer is not significant.The inflection rate and the maximum growth rate of all treatments were better than those in the control group except for the potash group.All the groups that applied the fertilizer treatment pushed back the fast-growing time of the seedling path,and the increases of inflection point are better than that of control group.The growth rate o f the control group is the highest.?2?The effects of continuous drought?with a treatment period of 5d,a total of 30d?and rewatering in the growth and physiological characters of M.chinensis were studied.The results show that under the drought stress,the growth of the seedlings had been greatly affected,and the growth of the stem diameter increased with the time.Seedlings?roots,stems,leaves and soil natural water content show a downward trend.The osmotic adjustment material contents in the leaves had changed,especially the contents of chlorophyll,carotenoid,SOD activity,and soluble protein were increased first and then decreased.And the content of MDA and proline increased by time.The growth of seedlings continued after rewatering,and the increase of seedling height and the increase of ground diameter were inversely proportional to the intensity of stress.There was a negative correlation between the restoration degree of soil and root natural water content and the degree of damage.The natural water content in stem and leaf,and the SOD activity,MDA,soluble protein and proline in the leaf were basically restored to normal level,which indicates that M.chinensis has a certain resistance to drought stress.?3?Through the L9?3⁴?orthogonal test design method,the effects of different N,P and K fertilizers on the growth and physiological characters of M.chinensis were studied.The results show that:the best treatment to the seedling height and ground diameter growth is N1P3K3?N:0.375 g/pot,P:0.045 g/pot,K:0.12 g/pot?.N1P1K1?N:0.375 g/pot,P:0.18g/pot,K:0.24 g/pot?has the highest ratio of height to diameter—10.556,while the control group is 6.694,indicating that the ratio of N,P,K fertilization had a positive effect on seedling growth.The group N3P3K2?N:0.75 g/pot,P:0.045 g/pot,K:0.48 g/pot?has the most biomass accumulation.N3P3K2?N:0.375 g/pot,P:0.045 g/pot,K:0.48 g/pot?and N1P3K3?N:0.375 g/pot,P:0.045 g/pot,K:0.12 g/pot?are the most effective groups for promoting fresh weight per unit leaf area,fresh weight per leaf and dry weight per leaf.The establishment of N3P1K3?N:0.75 g/pot,P:0.18 g/pot,K:0.12 g/pot?is the most important factor to increase the pigment content.After establishing and analyzing the physiological indexes and the polynomial regression equation of N,P and K,the appropriate ranges were found,which are N:0.485-1.430 g/pot,P:0.119-0.244 g/pot,and K:0.332-0.458 g/pot.?4?The effects of AM mycorrhizal to the growth and nutrient distribution of the M.chinensis seedlings were studied to provide theoretical support for the cultivation and breeding of Machilus.The results show that isolate 9004 and isolate 90068 had a greater effect on seedling height growth and ground diameter growth.Isolate 90068 and Glomus mosseae had higher biomass accumulation.The addition of inoculation also significantly promoted leaf number,leaf size,chlorophyll content and plant water content of seedlings.In terms of mineral elements,the nitrogen content of each part of the plant inoculated with AM mycorrhizal is higher than that of the control group.Root phosphorus content is lower than the control group,there is no significant difference in the content of stem,but leaf phosphorus content is slightly higher than that of the control group,while the proportion of nitrogen and phosphorus in stems and leaves of AM mycorrhizal is significantly increased.It indicates that inoculating AM mycorrhizal can promote plant growth and nitrogen absorption,also change the nitrogen and phosphorus elements?distribution and proportion in the plant body.