4种除草剂对紫花苜蓿-根瘤菌共生固氮的影响

Influence of Four Herbicides on Rhizobium-Alfalfa Symbiotic Nitrogen-Fixation

在室内条件下,研究了乙羧氟草醚、三氟羧草醚、乙草胺和异丙甲草胺等4种除草剂对紫花苜蓿-根瘤菌共生固氮的影响。结果表明:4种除草剂均能对紫花苜蓿-根瘤菌共生固氮产生一定的抑制作用,其中以乙羧氟草醚的抑制作用最强,在高剂量下鲜重抑制率和干重抑制率分别为68.5%,70.6%,与对照植株的结瘤率和总含氮量92%和2.620%相比,其结瘤率和总含氮量为31%和0.072%;异丙甲草胺的抑制作用最弱,高剂量下鲜重抑制率和干重抑制率分别为18.5%和26.8%,与对照植株的结瘤率和总含氮量94%和2.136%相比,其结瘤率和总含氮量为60%及0.482%;紫花苜蓿经四种除草剂不同剂量处理后,总含氮量远远低于对照植株的总含氮量。

The effects of 4 herbicides,namely,fluoroglycofen-ethyl,acifluorfen,acetochlor,metolachlor on rhizobium-alfalfa symbiotic nitrogen-fixation were studied.The results revealed that:the 4 herbicides had inhibitory effects on rhizobium-alfalfa symbiotic nitrogen-fixation,while fluoroglycofen-ethyl exhibited the strongest inhibitory effect,at high dosage,reduced fresh weight and dry weight by 68.5% and 70.6%,respectively,comparison with nodulation and total nitrogen content without herbicides: 92% and 2.620%;fluoroglycofen-ethyl reduced nodulation and total nitrogen content by 31% and 0.072%,respectively;metolachlor had the least inhibitory effects,at the high dosage,reduced fresh weight,dry weight,nodulation and total nitrogen content by only 18.5%,26.8%,60% and 0.632%,respectively;while the nodulation and total nitrogen content without herbicides reached 94% and 2.136%.Total nitrogen content was obviously reduced for all treatments.