Effects Of Shading And Fertilization On Growth Characteristics Of Empetrum Nigrum Var.japonicum

Taking Empetrum nigrum var.japonicum as experimental materials,this thesis set single factor experiments with four shading levels and four fertilization levels to observe the indexes such as growth conditions and biomass of branches,leaves,and buds of Empetrum nigrum var.japonicum under different shading and fertilization levels.Moreover,single factor analysis of variance and multiple comparisons of mean value were performed to clarify the effect of shading and fertilization treatment on thegrowth of Empetrumnigrumvar.japonicum.The researchresults showed that:75% shading had a significant effect on branch length and branch diameter.It could facilitate the growth of branch length but restrain that of branch diameter,making the plant thin.In contrast,the branches were short and thick under full exposure.Different light levels could affect the proportional distribution of different branch grades and the growth conditions of these branches.Compared with the control group,the proportion of <1 cm and 1～2 cm branch grades all decreased but the proportion of≥2 cm branchgrades all increased under25%,50%,and 75% shading.Moreover,the proportion of1～2 cm branch grades decreased the most,the proportion of ≥2 cm branch grades increased the most,and the branch diameter of all branch grades reduced under 75% shading.There were no significant differences in the number of leaves per branch under the four light levels,but the leaf length increased remarkably under 25% shading,and the leaf length,leaf width,and unit leaf area all markedly decreased under 50% and 75% shading.The number of flower buds per branch reduced obviously under 75% shading,with only average 0.79 flower buds per branch,and the proportion of branches without flower buds reached 76.44%,which was higher thanall other light levels.Shading,especially75% shading,could reduce the biomass of branches,leaves,and buds as well as total biological accumulation,decrease the biomass distribution of leaves and buds,and increase the biomass distribution of branches.Empetrum nigrum var.japonicum chose different survival strategies to adapt to a light environment under different light levels.In the case of low light levels,the branch length increased,and theproportion of its biomass allocation rose,which would improvethe creeping spread ability of the plant and help give play to soil and water conservation function,but the average number of flower buds per branch reduced obviously,and the proportion of bud biomass allocation was only1.65%,which would be bad for the reproductive growth of the plant.In the case of full exposure,the branches were short and thick,the leaves were long and wide,both the unit leaf area and the average number of flower buds per branch remarkably increased,and the biomass allocation of leaves and flower buds also increased,which would be good for the reproductive growth of the plant and meanwhilebe moresuitable for thecultivation ofmedicinal parts.The fertilization level of 64 g/m~2 had a remarkable effect on branch length,and it could promote the growth of branch length.The fertilization level of 8 g/m~2 had an obvious effect on branch diameter,and it could make the branch diameter thick.Different fertilization levels could affect the proportional distribution of different branch grades and the growth conditions of these branches.Compared with the control group,the proportion of <1 cm branch grades all decreased but the proportion of 1～2 cm branch grades all increased under the fertilization levels of 8 g/m~2,33 g/m~2,and 64 g/m~2.In addition,the proportion of <1 cm branch grades increased the most under the fertilization level of 8 g/m~2,while the proportion of <1 cm branch grades decreased the most under the fertilization level of 64 g/m~2.The proportion of ≥2 cm branch grades decreased under the fertilization level of 8 g/m~2,while the proportion of ≥2 cm branch grades increased under the fertilization levels of 33 g/m~2 and 64 g/m~2.There were no significant differences in the number of leaves per branch under the four fertilization levels.Under the fertilization level of 8 g/m~2,the leaf length increased remarkably,while the leaf width and unit leaf area markedly decreased.Under the fertilization levels of 33 g/m~2 and 64 g/m~2,the leaf length and unit leaf area significantly decreased.With the increase of fertilization levels,the average number of flower buds per branch markedly decreased,the proportion of branches without flower buds rose,and the proportion of branches with flower buds reduced.Fertilization could reduce the biomass of branches,leaves,and buds as well as total biological accumulation,decrease the biomass distribution of leaves and buds,and increase the biomass distribution of branches.According to the experiments,it could be known that in the case of64 g/m~2 fertilization level,the branch length increased,and the proportion of its biomass allocation rose,which would improve the creeping spread ability of the plant and help give play to soil and water conservation function,but the average number of flower buds per branch reduced obviously,and the proportion of bud biomass allocation decreased,which would be bad for the reproductive growth of the plant;and in the case of no fertilization,the branches were short and thick,the leaves were long and wide,both the unit leaf area and the average number of flower buds per branch remarkably increased,and the biomass allocation of leaves and flower buds also increased,which would be good for the reproductive growth of the plant and meanwhile be more suitable for the cultivationof medicinal parts.