紫茎泽兰对蓝桉种子萌发及苗生长的化感作用

摘要

紫茎泽兰为桉树林下革本层的优势种,为探讨紫茎泽对蓝桉种子萌发及苗生长的化感作用,采用盆栽试验,用其叶不同浓度水提液(0,0.005,0.01,0.02,0.04 g/mL)对蓝桉种子进行处理.结果表明:不同浓度水提液对蓝桉种子萌发(发芽速率、发芽势、发芽率)、苗生长(地径、高度)及生物量(根重、茎重、叶重、总重)均有显著的影响;随着处理浓度的增加,种子萌发、苗生长、生物量受抑制作用增强;种子萌发、苗生长、生物量与处理浓度之间均呈极显著负相关.处理60 d比处理30 d对苗生长的化感抑制作用加大,说明蓝桉幼苗生长受抑制作用随处理时间延长而增大.在林下及林缘广泛分布的紫茎泽兰,可通过化感作用影响蓝桉的天然更新和生长.%Eupatorium adenophorum is the dominant species in herb layer of Eucalyptus spp.forests,to discuss the allelopathy of E.adenophorum on seed germination and seedling growth of Eucalyptus globulus,E.globulus seeds were treated by leave aqueous extract of E.adenophorum of different concentration (0、0.005、0.01、0.02、0.04 g/mL).The results showed that extract treatment had a signif icant influence on seed germination (germination potential,germination rate,germination speed),seedling growth (base diameter,height),biomass (root weight,stem weight,leaf weight,total weight) of E.globulus.Seed germination,seedling growth and biomass were inhibited by the treatment,the negative effect became stronger with increasement of the extract concentration.The seed germination,seedling growth and biomass were very significantly negatively correlated with the extract concentration,the indice were decreased in a line with increasement of the extract concentration.The inhibition on seedling growth after treated by the extract for 60 days was stronger than that after treated by the extract for 30 days,this indicated that the inhibition became stronger with the increasement of the treatment time.E.adenophorum were widely distributed in the ground and at the periphery of E.globulus forest,and may influence natural regeneration and growth of E.globulus by allelopathy.