不同人工经济林凋落叶浸提液对豆禾草种的化感效应研究

Allelopathic effects of different artificial economic forest litter extracts on Fabaceae and Poaceae species

红枣、核桃以及苹果是陕北地区主要的人工经济林树种,且种植方式单一。为探讨人工经济林对牧草生长的化感作用,本研究以紫花苜蓿和黑麦草作为研究受体,通过设置不同浓度核桃、苹果、红枣凋落叶浸提液,分析其对豆禾草种种子萌发及幼苗生长的影响。结果表明:1)紫花苜蓿和黑麦草的发芽率和发芽势随浸提液浓度的增加而显著降低(P<0.05);2)苹果和红枣凋落叶浸提液浓度越高,紫花苜蓿、黑麦草幼苗叶绿素含量和根系活力越低,核桃凋落叶浸提液处理下黑麦草幼苗的叶绿素含量显著高于对照组,根系活力显著低于对照组(P<0.05);3)两种牧草的生化指标结果表明,黑麦草的抗氧化能力强于紫花苜蓿。豆禾草种种子萌发及幼苗生长对不同树种、不同浓度凋落叶浸提液的化感响应存在差异,整体而言,人工经济林凋落叶浸提液对紫花苜蓿的化感作用强于黑麦草。本研究旨在为陕北地区林草混种提供理论依据,在建植过程中应充分考虑豆禾草种与经济林的搭配。

Ziziphus jujuba,Juglans regia,and Malus pumila are dominant artificial economic forest tree species in northern Shaanxi,while they are usually planted as pure plantations.To explore the allelopathic effects of these artificial economic forests on the growth of forage species,Medicago sativa and Lolium perenne were used as receptors.These receptors were treated using Z.jujuba,J.regia and M.pumila leaf extracts with different concentrations to analyse their effects on seed germination and seedling growth of forage species.The results showed that:1)The germination rate and germination potential of M.sativa and L.perenne decreased significantly with the increase of the concentration of the leaching solution(P<0.05);2)Higher concentrations of M.pumila and Z.jujuba leaf litter extract led to lower root activity and chlorophyll content of M.sativa and L.perenne.The chlorophyll content of L.perenne seedlings treated with J.regia leaf extract was significantly higher than that of the control group,and the root activity was significantly lower than that of the control group(P<0.05);3)The biochemical indicators of two forage species indicated that the antioxidant capacity of L.perenne was significantly stronger than that of M.sativa.There were differences in the allelopathic responses of the seed germination and seedling growth of Fabaceae and Poaceae species to different tree species and different concentrations of leaf litter extracts.Overall,the allelopathic effects of artificial economic forest leaf litter extracts on M.sativa was stronger than those on L.perenne.This study aimed to provide a theoretical basis for the mixed planting of economic tree sand forage species in northern Shaanxi,and the combination of Fabaceae and Poaceae forage species and economic forests should be fully considered during the planting process.