薇甘菊化感自毒作用及其生态学意义

化感自毒作用是同种植物个体之间的一种化学作用,是植物经过长期适应环境和进化选择而获得的一种种内有序竞争机制.依次用正己烷、乙酸乙酯、乙醇三种有机溶剂和水分别对薇甘菊(Mikania micrantha H.B.K)地表茎叶和地下根系进行梯度提取并配制成一定质量浓度的营养液,后采用营养液扦插法培养薇甘菊幼苗,12 d后测其生长情况.结果表明:薇甘菊不同部位的不同溶剂提取物对其幼苗生长的抑制作用存在差异,但茎叶和根系的不同溶剂提取物对其幼苗生长的综合抑制效应对应一致,幼苗受抑制程度均为:乙酸乙酯>乙醇>水>正己烷.薇甘菊不同部位的不同溶剂提取物对其幼苗新生根长、新生株高和新增鲜质量之间的抑制率存在差异,三者受抑制程度总体表现为:新生株高>新生根长>新增鲜质量;且地表茎叶不同溶剂提取物对其幼苗生长的抑制作用强于其对应的根系提取物.

Allelopathic Autotoxicity Effects of Mikania micrantha H. B. K and Its Ecological Significance

The allelopathic autotoxicity is a chemical interaction among intra-specific plant individuals. It is a mechanism of the plant to avoid competitions that acquired through a long time of adapting environment and evaluating selection. The allelopathic autotoxicity of 4 solvent extraction from overground part and root of Mikania micrantha H. B. K was studied. The seedlings of Mikania micrantha H. B. K were cultured in solution with special concentration of nutrient solution and 4 solvent extraction 12 days. The results showed :4 solvent extraction from overground part and root had different inhibition rate of its seedling growth and synthetic inhibitory effect had homologous consistency of overground part and root from Mikania micrantha H. B. K. The synthetic inhibitory effect of 4 solvent extraction followed the order: ethyl acetate>alcohol>aqueous>n-hexane.4 solvent extraction from overground part and root have different inhibition rate of growth on weight, shoots and roots to seedling of Mikanla micrantha H. B. K, the synthetic inhibitory effect followed the order:shoots>roots>weight and the inhibition rate of overground part higher than root.