作 者 ：韩利红,冯玉龙
期 刊 ：生态学报 2007年 27卷 3期 页码：1185~1191
Keywords:Eupatorium adenophorum, allelopathy, growth and development stage, invasiveness,
摘 要 ：为探讨紫茎泽兰化感作用与其入侵性的关系，利用生物检测法研究了不同发育时期紫茎泽兰叶片水提液对4种本地草本植物种子萌发和幼苗生长的影响。结果表明，高浓度时紫茎泽兰叶片水提液能显著抑制4种本地植物种子发芽率、发芽速度，但低浓度时有时抑制作用不显著，甚至有促进作用；除狗肝菜胚轴生长外，不同浓度下紫茎泽兰叶水提液均能抑制4种本地植物胚轴和胚根生长，但有时对胚轴生长的抑制作用不显著，甚至有促进作用。不同植物和同种植物的不同参数对紫茎泽兰化感作用的敏感程度不同，拔毒散和狗肝菜的种子萌发参数较敏感，莎草砖子苗的生长参数较敏感，种子发芽速度和胚根生长较敏感。总的看，随发育时间的增加，紫茎泽兰抑制本地植物种子萌发和幼苗生长的最低叶片提取液浓度减小，相同浓度下叶片水提液对本地植物的抑制作用增强，表明紫茎泽兰化感作用增强。化感作用在紫茎泽兰入侵的不同阶段所起的作用可能不同。
Abstract:As one of the most noxious plant invaders in China, Eupatorium adenophorum Sprengel not only severely threatens the biodiversity security but also leads to huge economic costs to the country. E. adenophorum has allelochemicals, which can inhibit seed germination of some species, such as pea, sensitive to allelochemicals. However, The effects of E. adenopherum′s allelochemicals on wild species that compete directly with it during the early stage of invasion are not very clear. Furthermore, the relationship between allelopathy and invasiveness is not known in E. adenophorum although it had been hypothesized that allelopathy plays an important role in biological invasion for other invasive species. In this study, the effects were determined of aqueous extract of leaves collected from 6 growth and developmental stages (from 60 d to 925d old plants) on seed germination and seedling growth of 4 herbaceous species. The main purpose of this study was to know whether allelopathy was development dependent in E. adenopherum, and the relationship between invasiveness and allelopathy.
Allelopathy of E. adenophorum was concentration dependent. At high concentration, aqueous leaf extract of E. adenophorum could significantly inhibit seed germination rate and speed of the four studied native species, whereas its effect was not significant occasionally at lower concentration or even increased seed germination. At both high and low concentration, E. adenophorum leaf extract could inhibit radicle and hypocotyl growth of the four natives except hypocotyl growth of Dipliptera roxburghiana, but occasionally its effect was not significant or even increased hypocotyl growth. The sensitivities to E. adenophorum′s allelochemicals were different among different native species and among different variables of the same species. Variables related to seed germination were more susceptible for Sida szechuensis and D. roxburghiana than for Isodon ternuifolia and Mariscus cyperinus, while growth-related variables more susceptible for M. cyperinus than for the others. Seed germination speed was more susceptible than germination rate; and radicle than hypocotyls. In general, with the increase of development stage, the inhibitory effects on natives of E. adenopherum leaf extract at the same concentration increased and the lowest inhibitory concentration decreased. The results indicated that allelopathy increased with development in E. adenopherum, and the role of allelopathy may be different at different stage of invasion.