果树凋落叶浸提液对多年生黑麦草和紫花苜蓿的化感效应

Allelopathic effects of litter extracts from fruit trees on Lolium perenne and Medicago sativa

【目的】探讨陕北地区红枣、核桃及苹果凋落叶的化感效应,为选择经济林下适生草种提供理论指导。【方法】以室外盆栽牧草多年生黑麦草和紫花苜蓿为材料,设置不同浓度红枣、核桃和苹果凋落叶浸提液(0.1,0.05,0.025,0.0125 g/mL)处理,测定牧草生长和生理指标。【结果】(1)牧草单株干质量在3类凋落叶各浓度浸提液处理下大多比对照显著降低,且红枣浸提液的降幅较小。(2)牧草丙二醛含量在3类浸提液处理下均高于对照,而红枣浸提液的增幅较小,其叶绿素含量、抗坏血酸含量和抗氧化酶活性变化在3类浸提液间存在明显差异,且多年生黑麦草的变幅明显大于紫花苜蓿。(3)3类浸提液对牧草根系性状的影响存在明显差异,均抑制其根长生长,明显抑制多年生黑麦草根尖数,而促进紫花苜蓿根尖数。【结论】3种果树凋落叶浸提液对2种牧草生长多表现出显著抑制作用,并以红枣浸提液的抑制作用最小,且多年生黑麦草生长受抑制程度小于紫花苜蓿。

[Objective]The study aims to investigate the chemosensory effect of fading leaves of Ziziphus jujuba,Juglans regia,and Malus pumila in northern Shaanxi,and to provide theoretical guidance for the selection of suitable grass species under economic forests.[Methods]Outdoor potting forage Lolium perenne and Medicago sativa were set up with different concentrations of Z.jujuba,J.regia,and M.pumila withered leaf extracts(0.1,0.05,0.025,0.0125 g/mL)treatments to determine the growth and physiological indexes of the forage.[Results](1)The dry mass of forage monocultures was significantly lower than the control in most of the three types of withered leaves treated with each concentration of leachate,and the decrease was smaller in the Z.jujuba leachate.(2)Forage malondialdehyde content was higher than the control under all three types of leachate treatments,while the increase in Z.jujuba leachate was smaller,and the changes in its chlorophyll content,ascorbic acid content and antioxidant enzyme activity differed significantly among the three types of leachates,and the variability of L.perenne was significantly greater than that of M.sativa.(3)There were significant differences in the effects of the three types of extracts on the root traits of the forages,all of which inhibited their root length growth,significantly inhibited the number of L.perenne root tips,and promoted the number of M.sativa root tips.[Conclusion]Three kinds of fruit tree leaf extract showed significant inhibition on the growth of two kinds of forage grasses,and the inhibitory effect of Z.jujuba extract was the smallest,and the growth of L.perenne was less inhibited than that of M.sativa.