加拿大一枝黄花对紫花苜蓿和红苋菜的化感效应研究

研究了加拿大一枝黄花地上部分（茎和叶）、地下部分（根茎和细根）和根际土壤的水浸提液对紫花苜蓿和红苋菜两种经济作物种子萌发和幼苗生长的影响。结果表明：（1）地上部分、地下部分和根际土壤的浸提液对紫花苜蓿种子的萌发均起抑制作用,而对红苋菜种子的萌发具有一定促进作用。（2）地上部分的浸提液对紫花苜蓿和红苋菜的苗高、根长以及紫花苜蓿的根重均表现出抑制作用,而对红苋菜的根重更多的是表现出促进作用。（3）地下部分的浸提液对紫花苜蓿和红苋菜的苗高、根长以及根重（粗）均表现出抑制作用。（4）根际土壤的浸提液对紫花苜蓿的根长以及根重均表现出抑制作用,而对苗高起促进作用;对红苋菜的根长起抑制作用,而对苗高和根重既起促进作用又起抑制作用。（5）相同浓度的水浸液对作物幼根的影响大于对作物苗高的影响。（6）当浸提液的浓度变化时,不同作物种子的萌发和幼苗生长的响应对策呈显著差异。

Allelopathic effects of Solidago canadensis on Medicago sativa and Amaranthus paniculatus

Effects of the water extracts of the aerial part(stem and leaf),underground part(rhizome and rootlet)and rhizosphere soil of S.canadensis on the seed germination and seedling growth of M.sativa and A.paniculatus two economic crops were studied.The results showed that(1)al J the water extracts inhibited seed germination of M.sativa but somewhat facilitated seed germination of A.paniculatus;(2)The water extract of S.Canadensis'aerial part suppressed the seedling height,root length and root weight of M.sativa and the seedling height and root length of A.paniculatus,but had an accelerating effect on the root weight of A.paniculatus;(3)The water extract of S.Canadensis'underground part inhibited the seedling height,root length and root weight of both M.sativa and A.paniculatus;(4)The water extract of rhizosphere soil of S.Canadensis suppressed the root length and weight of M.sativa and the root Iength of A.paniculatus,but accelerated the seedling height of M.sativa,and had both accelerating and inhibiting effects on the seedling height and root weight of A.paniculatus;(5)The water extract of S.Canadensis with the same concentration had a greater effect on the crops'radicles than on their seedling heights;(6)When the water extract concentration changed,the responses of different crops in seed germination and seedling growth were significantly different.