国槐凋落叶浸提液对4种药用植物的化感作用OA

[Objective]The study aims to investigate the allelopathic effects of aqueous extracts from fallen leaves of Styphnolobium japonicum on four medicinal plants,to provide theoretical support for the cultivation of medicinal plants in S.japonicum forests.[Method]The seeds and seedlings of four medicinal plants,namely Anemarrhena asphodeloides,Taraxacum mongolicum,Agastache rugosa and Sophora flavescens,were used as experimental materials.The filter paper seed germination method in culture dishes was combined with the indoor seedling pot cultivation method,and five treatment concentrations were set:0(distilled water as the control),7.5,15,30,and 60 g/L.The germination rate,germination potential,germination index,vigor index,root length,and seedling length were measured 14 days after the germination.The SOD and POD activities,soluble sugar content,soluble protein content,and proline content of potted seedling leaves were also measured after 60 days of cultivation.The effects of aqueous extract of S.japonicum leaves on seed germination and seedling growth of the four medicinal plants were analyzed.[Result]①Different concentrations of aqueous extracts of fallen leaves of S.japonicum had significant effects on seed germination and seedling growth of the four medici-nal plants.Compared with the control group,treatment of 60 g/L extract resulted in the greatest reduction in the germination rate,germination index,vigor index and root length of T.mongolicum seeds,which were 61.36%,82.69%,97.62%and 86.63%,respectively.The strongest inhibitory effect was observed on the height of A.asphodeloides,which was significantly reduced by 50.88%.The root length and seedling height of S.flavescens.significantly increased by 18.48%and 57.85%,respectively,under the treatments of 7.5 and 30 g/L extract.The highest increase in the seedling height of A.rugosa(82.38%)was observed under the 30 g/L treatment.Meanwhile,under the treatment of 60 g/L extract,the relative changes in the synthetica lallelopathic effect index of A.asphodeloides,T.mongolicum,A.rugosa,and S.flavescens.compared to the control group were-0.65,-0.66,-0.54,and-0.36,respectively.② As the concentration of the extract increased,the SOD activity in the leaves of A.rugosa and S.flavescens first decreased and then increased,compared with the control,with the highest increases observed under the 60 g/L treatment,which were 18.55%and 7.89%,respectively.The SOD activity of A.asphodeloides and T.mongolicum first increased and then decreased,with the highest in-creases observed under the 15 g/L treatment,which were 5.21%and 21.78%,respectively.The POD activity of leaves continued to increase in A.asphodeloides,with the highest increase of 112.19%observed under the 60 g/L treatment.The POD activity of leaves first increased and then decreased in T.mongolicum,and it first de-creased and then increased in A.rugosa and S.flavescens.③The soluble protein content of A.rugosa,A.aspho-deloides and S.flavescens.seedling leaves increased and then decreased with the increase of the concentration of the extracts,and the soluble protein content of S.flavescens.leaves was significantly increased by 64.54%under the 7.5 g/L treatment.The soluble sugar content of the seedling leaves of all the medicinal plants reached the highest or second-highest level(for A.asphodeloides)under the 30 g/L treatment.At this concentration,the soluble sugar content of A.rugosa,A.asphodeloides,T.mongolicum and S.flavescens.increased by 80.76%,120.93%,39.35%and 101.01%,respectively,compared with that of the control group.The proline content of T.mongolicum seedling leaves was significantly lower than that of the control group in all treatment groups,with the lowest level observed under the 60 g/L treatment,which was significantly reduced by 47.50%com-pared with that of the control group.④The allelopathic intensity of aqueous extracts from fallen leaves of S.ja-ponicum on four medicinal plants was ranked as follows:T.mongolicum>A.asphodeloides>A.rugosa>S.fla-vescens.[Conclusion]Seeds and seedlings of S.Flavescens and A.rugosa show strong tolerance to the extract of fallen leaves of S.japonicum,while T.mongolicum and A.asphodeloides show poor tolerance.