杀菌剂对沙打旺种子萌发和幼苗生长的短期影响

摘要

病害是导致沙打旺(Astragalus adsurgens)草地产量下降的主要原因之一.本研究用杀菌剂对沙打旺种子进行预处理,在培养皿和盆栽两种培养条件下模拟沙打旺种子在自然环境中受到不同病原真菌侵染后的萌发和生长状况,探讨杀菌剂预处理的作用和效果.结果表明,人工接种病原菌后,经杀菌剂处理的种子,其发芽率,植株的株高、根长和干重较无菌水处理种子显著提高(P<0.05),而发病率、死亡率和平均病情指数则相应地显著降低(P<0.05).不同杀菌剂的防治效果有所不同,在多菌灵、代森锰锌和甲基托布津3种杀菌剂中,代森锰锌预处理防治效果最好.%Fungal disease is the main factor reducing perennial forage's biomass of standing milk vetch (Astragalus adsurgens).In this study,the seeds of standing milkvetch were pretreated with three kinds of fungicide: carbendazim,mancozeb and thiophanate-methyl,with the purpose of evaluating the fungicide effects,seed germination and seedling growth after inoculation through resembling the natural environment.The results suggested that three kinds of fungicide treatments significantly(P<0.05) improved the seed germination in petri dishes and pots compared with sterile water controls,and the plant height,root length as well as dry weight revealed a uniform trend.Significant reductions of incidence,mortality and average disease severity index (DSI) were caused by the fungicides.Based on the results,the fungicides have different roles on seed germination and seedling growth under the pathogen conditions,of which mancozeb was the best choice in this study.