草甘膦对党参生长根腐病及根际土壤微生物的影响

Effects of Glyphosate on Growth,Root Rot and Rhizosphere Soil Microbes of Codonopsis pilosula

目的:探究除草剂草甘膦对党参生长、根腐病发生和药用成分的影响及可能的土壤微生态机制。方法:调查同一地块中草甘膦处理组和对照组党参的存苗数、鲜质量和发病情况,采用高效液相色谱法(HPLC)测定党参炔苷含量、分光光度法测定多糖含量,采用扩增子技术测定根际土壤微生物群落变化。结果:施用草甘膦能够显著降低党参的存苗数(P<0.05),对党参地上部生长有一定抑制作用;根腐病发病率及病情指数高于对照组,分别增加了34.51%和34.81%(P<0.05);党参炔苷和多糖的含量降低。另外,草甘膦处理对党参根际土壤微生物的多样性及真菌群落结构影响较小,但细菌群落中伯克霍尔德氏菌目(Burkholderiales)和鞘脂单胞菌目(Sphingomonadales)显著增加(P<0.05)。结论:施用草甘膦对党参生长有一定抑制作用,导致根腐病加重,这可能与部分根际细菌的相对丰度变化有关。

Objective:To explore the effects of herbicide glyphosate on the growth,root rot occurrence,and medicinal ingredients of Codonopsis pilosula and the possible soil micro-ecological mechanism.Methods:This study investigated the number of seedlings,fresh quality and disease status of C.pilosula in glyphosate treatment group and control group in the same C.pilosula planting plot.High performance liquid chromatography(HPLC)and spectrophotometry were used to determine the content of lobetyolin and polysaccharides,respectively,and amplicon sequencing was performed to detect the microbial community in rhizosphere soil.Results:The application of glyphosate significantly reduced the number of seedlings of C.pilosula(P<0.05),and also had a certain inhibitory effect on the growth of the aerial parts of C.pilosula.The incidence rate and disease index of root rot in glyphosate treatment group were higher than those of the control group,increasing by 34.51%and 34.81%,respectively(P<0.05),and the content of lobetyolin and polysaccharides decreased.In addition,glyphosate had no remarkable effect on the microbial diversity and fungal community structure in the rhizosphere soil of C.pilosula,but Burkholderiales and Sphingomonadales in the bacterial community increased significantly(P<0.05).Conclusion:Glyphosate had a certain inhibitory effect on the growth of C.pilosula,aggravating root rot,which might be related to the relative abundance of some rhizosphere bacteria.