醉马草根围土壤对牧草种子萌发的影响

Effects of rhizosphere soil of Achnatherum inebrians on forages seed germination

为了探讨醉马草(Achnatherum inebrians)根围土壤对牧草种子萌发的化感作用,采用培养皿滤纸法在人工气候箱中,研究了秋季醉马草根围土壤0-5、5-10、10-15和15-20cm 4个土层水浸液在2、1、0.2和0.1g·mL-14个质量浓度下对无芒雀麦(Bromus inermis)、紫花苜蓿(Medicago sativa)和红豆草(Onobrychis viciaefolia)3种牧草种子萌发的影响。结果表明,醉马草根围土壤水浸液对3种牧草种子萌发率、发芽势、萌发指数、胚根长、胚芽长、根芽重没有明显的规律性。从综合化感效应指数来看,3种牧草萌发受限从强到弱依次为紫花苜蓿>无芒雀麦>红豆草,水浸液对无芒雀麦和红豆草不存在抑制作用,对紫花苜蓿具有一定的抑制作用,浓度越大抑制作用越强;各土层水浸液对无芒雀麦和红豆草呈现促进作用,5-10,10-15和15-20cm 3个土层对紫花苜蓿起着一定的抑制作用。醉马草水浸液的化感作用在低浓度条件下(0.2g·mL-1)对无芒雀麦和红豆草种子萌发具有显著促进作用,但其他浓度间具有一定的波动性,整体化感效应表现出随着浓度增加促进作用减弱。

In order to investigate the allelopathy of aqueous extracts from rhizosphere soil of Achnatherum inebrians on the seed germination of forages,the influence of aqueous extract of rhizosphere soil from autumn A.inebrians in 0-5,5-10,10-15,15-20 cm layer with the concentrations of 2,1,0.2,0.1g·mL-1 on the seed germination of Bromus inermis,Medicago sativa,Onobrychis viciaefolia were studied through the standard germination test.The result showed that effects of aqueous extract of rhizosphere soil on the germination rate,germination potential,germination index,radicle length,shoot length,root to shoot weight of three pasture seed were not consistent.Based on the index of comprehensive allelopathic effects,the intensity of restriction to germination of three forages were in the order of M.sativa>B.inermis>O.viciaefolia.The aqueous extracts had no inhibition on B.inermis and O.viciaefoliaseed germination whereas they had some inhibition on M.sativa seed germination which increased with the increase of extract concentration.The aqueous extract in 5-10,10-15 and 15-20 cm layer from each layer promoted seed germination of B.inermis,O.viciaefolia whereas they had inhibition on M.sativaseed germination which had significant inhibition(P<0.05).The aqueous extract of rhizosphere soil from A.inebrians with 0.2g·mL-1 concentrations had significantly promoted(P<0.05)the seed germination of B.inermis and O.viciaefolia.The allelopathy of other aqueous extracts concentrations did not perform consistently which decreased with the concentrations increasing.