蓝桉对紫茎泽兰的化感作用及其生物测定

Allelopathic Effect of Eucalyptus Globulus Labill on Eupatorium Adenophorum Sprengel and its Bioassay Method

测定了蓝桉叶水提液(2%、5%、10%)、抽提后的蓝桉叶(2g、5g、10g)和阴干蓝桉叶(2g、5g、10g)对紫茎泽兰种子萌发和幼苗生长的影响。结果表明:蓝桉叶水提液能降低紫茎泽兰种子发芽率、发芽速度、胚根和胚轴长度及幼苗生长,浓度越高效果越明显(2%水提液对发芽率的作用除外),但低浓度有时会促进紫茎泽兰种子的萌发和幼苗新生叶片数;以蓝桉作为竞争植物与紫茎兰竞争以抑制其生长,且蓝桉不会对当地其他植物造成伤害。

Eupatorium adenophorum Sprengel is the most noxious plant invaders in China. The relationship between allelopathy and invasiveness is not known in E. adenophorum. In order to study the effect of Eucalyptus globulus Labill＇s allelochemicals on E. adenophorum, the way of laboratory bioassay has been used. In this study, the effect on seed germination and seedling growth of E. adenophorum is determined by aqueous extract of leaves, extracted leaves and dry leaves collected from different E. globules plants. The main purpose of this study was to find the relationship between E. lobules＇s allelochemicals and E. adenophorum＇s replacement control. The result shows that E. globules is concentration dependent. At higher concentration, aqueous leaf extract of E. globule could significantly inhibit seed germination rate, hypocotyls, radicle and seedling growth of E. adenophorum, whereas its effects are not significant occasionally at lower concentration or even increased seed germination and seedling growth. With the increase of the concentration of extracted leaves and dry leaves, the inhibition to seedling growth of E. adenophorum is heavier. The sensitivies to E. globules＇s allel- ochemicals are different among different variables. Variables related to seed germination are more susceptible than for seeding growth. New leaves number and biomass are more susceptible than for seeding basal diameter. The study didn＇t also shows that there isn＇t any bad effect of E. globules on other plants at different growth stages.