紫茎泽兰和黄蒿根际土壤对油菜化感作用的比较研究

Allelopathy Comparison of Eupatorium adenophroum and Artemisia scoparia Rhizosphere Soil on Rape Seed

紫茎泽兰(Eupatorium adenophroum)是一种典型的恶性入侵杂草,在入侵地可造成严重的生态破坏。前人研究发现紫茎泽兰根际分泌物对周围植物生长存在化感作用,并认为化感作用是其入侵扩张的主要原因之一。为了确认化感作用在紫茎泽兰入侵中的重要性,本研究首次将紫茎泽兰和本地杂草黄蒿(Artemisia sco-paria)的根际土壤对油菜(Brassica napus)的化感作用进行了比较研究。结果表明,两种植物根际土壤对油菜种子萌发均有较强抑制作用,黄蒿根际土壤发芽抑制率(46.7%)极显著高于紫茎泽兰土壤(20.0%)(P<0.01);试验第4天测定结果显示,紫茎泽兰和黄蒿对油菜根长和芽长的抑制作用极显著(P<0.01),而紫茎泽兰和黄蒿的根长抑制作用差异不显著(P>0.05)。以上结果说明紫茎泽兰和黄蒿均存在化感作用,仅用化感作用不足以解释紫茎泽兰入侵扩张力强的原因。

Eupatorium adenophroum is a notorious invasive weed,which leads to serious economic and biodiversity loss in invasion areas.Previous studies found that the exudation around the rhizosphere of E.adenophroum can strongly inhibit the growth of neighboring plants,which is called allelopathy.Allelopathy is considered as one of the important reasons of strong expansion and invasion of this weed.To confirm the importance of allelopathy,we compared the allelopathy of rhizosphere exudation of E.adenophroum with that of Artemisia scoparia on rape seed Brassica napus for the first time.The results showed that both E.adenophroum and A.scoparia significantly inhibited sprout of B.napus,and inhibition rate of A.scoparia(46.7%) is significantly higher than that of E.adenophroum(20.0%)(P<0.01).The observation results of the fourth day indicated that the rhizosphere soil both of E.adenophroum and A.scoparia significantly inhibited shoot and root growth of B.napus(P<0.01),and the root inhibiting effect did not differ significantly between E.adenophroum and A.scoparia(P>0.05).Results above may indicate allelopathy is not an important reason for the strong invasion and expanding ability of E.adenophroum.