本氏针茅根际土提取物对本氏针茅及其优势种种子萌发的影响

以本氏针茅及其优势种大针茅和百里香种子为受体,采用生物检测的方法研究了0(对照)、0.1、0.2和0.5g/mL本氏针茅根际土甲醇浸提液和水浸提液对3种受体种子萌发的影响,以探究草地演替过程中物种间的生态关系和化感作用的表现形式。结果显示:(1)甲醇浸提液对3种受体种子的发芽均有抑制作用;水浸提液对本氏针茅发芽有促进作用,对百里香有部分促进作用,而对大针茅有抑制作用。(2)甲醇浸提液对本氏针茅和大针茅胚根和胚芽生长无显著影响,而抑制百里香胚根和胚芽的生长;水浸提液对本氏针茅胚根生长无显著影响,对本氏针茅胚芽生长具有显著促进作用,而对其它两种受体胚根和胚芽均无显著影响。(3)各种浓度甲醇浸提液对大针茅和百里香生长表现出了化感综合抑制效应,对本氏针茅生长于0.2g/mL时表现出化感综合抑制效应,其它2种浓度(0.1、0.5g/mL)表现为化感综合促进效应;水浸提液对本氏针茅和百里香表现为化感综合促进效应,而对大针茅表现为化感综合抑制效应。研究表明,本氏针茅根际土甲醇浸提液和水浸提液的化感物质存在差异;不同受体对同一浸提液反应不同,同一受体对不同浸提液的反应也不同。

Effect of the Extracts of Rhizosphere Soil from Stipa bungeana on the Germination of Stipa bungeana and Its Dominant Species

Allelopathy of 0(control treatment),0.1,0.2 and 0.5 g/mL methanol extracts and aqueous extracts of rhizosphere soil from Stipa bungeana were studied using the seeds of S.bungeana,its dominant species Stipa grandis and Thymus mongolicus as receivers and by laboratory bioassay methods.Compared with the control,the results showed that:(1)Methanol extracts inhibited the germination of S.bungeana,Stipa grandis.Aqueous extracts stimulated the germination of S.bungeana,and it stimulated the germination of T.mongolicus partialy,but inhibited that of S.grandis.(2)Methanol extracts had different effects on different receivers,it barely affected the growth of root and shoot of S.bungeana and S.grandis,but inhibited the growth of T.mongolicus significantly.Aqueous extracts could not stimulate the root growth of S.bungeana,the same to the root and shoot growth of the other receivers,but had significant stimulation to the shoot growth of S.bungeana.(3)Methanol extracts inhibited the growth of T.mongolicus and S.grandis,it stimulated the growth of S.bungeana except the concentration of 0.2 g/mL.Aqueous extracts stimulated the growth of S.bungeana and T.mongolicus,but inhibited that of S.grandis.Therefore,methanol extracts and aqueous extracts of rhizosphere soil from S.bungeana are different,and they have different effects on different receivers.one receiver has different reaction to different extracts.