高寒退化草甸优势种大狼毒对三种受体植物的化感作用

Allelopathic Effects of Dominant species Euphorbia jolkinii on Three Receptor Plants in Alpine Degraded Meadow

【目的】大狼毒(Euphorbia jolkinii)是滇西北退化高寒草甸常见的一种毒害型草本植物,常取代本土优良牧草而成为优势物种,因而给高寒草甸生态系统的可持续发展及当地畜牧业发展带来威胁,通过探究大狼毒是否会对周围其他周边草甸植物产生化感影响,揭示大狼毒在滇西北高寒草甸退化中的作用,为滇西北高寒草甸的退化防治与生态环境保护提供科学依据。【方法】采取野外调查与室内试验相结合的方式,分析大狼毒对高寒草甸植被群落多样性的影响,以及大狼毒的不同浸取液(包括不同浓度和部位)对紫云英(Astragalus sinicus)、黑麦草(Lolium perenne)和早熟禾(Poa annua)3种本土牧草植物的种子萌发及其幼苗生长的影响,进而探究大狼毒化感作用在滇西北高寒草甸退化中可能扮演的角色。【结果】(1)较之非大狼毒聚集区,大狼毒聚集区内草甸植物的多样性明显下降,表明大狼毒的存在对草甸植物的多样性具有显著的负面影响;(2)大狼毒根浸取液对3种受体植物的种子发芽率均有显著的抑制作用,叶浸取液只对早熟禾种子的发芽率有着明显的抑制作用,而茎浸取液对3种受体植物的种子发芽率均不存在显著的抑制效果。其中0.2 g/mL浓度的根浸取液对3种植物种子发芽率的化感效应最突出;(3)大狼毒根、茎、叶浸取液对3种受体植物幼苗高度有着一定的抑制作用,但不存在统计学显著性。【结论】大狼毒对滇西北高寒退化草甸植物多样性及3种本土植物种子发芽具有明显的化感作用,而对3种植物幼苗生长不存在明显的化感效应。

[Ojective]As a common poisonous herb in degraded alpine meadow in Northwest Yunnan,Euphorbia jolkinii often replaces local excellent forages and becomes a dominant species,which poses a threat to the sustainable development of alpine meadow ecosystem and the development of local animal husbandry.By exploring whether Euphorbia jolkinii will have allelopathic effects on other surrounding meadow plants,this study reveals the role of Euphorbia jolkinii in the degradation of alpine meadow in Northwest Yunnan,thus providing a scientific basis for the degradation control and ecological environment protection of alpine meadow in Northwest Yunnan.[Methods]This study analyzed the impact of Euphorbia jolkinii on vegetation community diversity of alpine meadow by combining field investigation and indoor experiment,and the effects of different extracts of Euphorbia jolkinii(including different concentrations and parts)on the seed germination and seedling growth of three native forage plants,Astragalus sinicus,Lolium perenne,and Poa annua,in order to explore the possible role of Allelopathy of Euphorbia jolkinii in the degradation of alpine meadow in Northwest Yunnan.[Results](1)Compared with non Euphorbia jolkinii aggregation area,the diversity of meadow plants in Euphorbia jolkinii aggregation area decreased significantly,indicating that the existence of Euphorbia jolkinii had a significant negative impact on the diversity of meadow plants.(2)The root extract of Euphorbia jolkinii had a significant inhibitory effect on the seed germination rate of the three receptor plants,the leaf extract had a significant inhibitory effect only on the seed germination rate of Poa annua,while the stem extract had no significant inhibitory effect on the seed germination rate of the three receptor plants.The allelopathic effect of 0.2 g/mL root extract on the seed germination rate of the three plants was the most prominent.(3)The extracts from roots,stems and leaves of Euphorbia jolkinii had a certain inhibitory effect on the seedling height of the three receptor plants,but there was no statistical significance.[Conclusion]Euphorbia jolkinii has obvious allelopathic effect on plant diversity and seed germination of three native plants in Alpine degraded meadow in Northwest Yunnan,but it has no obvious allelopathic effect on seedling growth of three plants.