摘要： 为了筛选对胡麻枯萎病有较好抗性的放线菌,试验对胡麻根围土壤进行了筛选,最终得到1株对胡麻枯萎病病原菌尖孢镰刀菌有较强拮抗作用的放线菌GS2-1。分别测定了它对不同地区分离得到的151株尖孢镰刀菌的抗性,发酵液对孢子和菌丝的抑制作用,研究了其最佳发酵条件,并对发酵液中的抑菌活性物质进行了初步提取和生物活性测定,最后对其在胡麻生长中的防病作用进行了研究。结果表明,GS2-1对151株尖孢镰刀菌均有较好的抗性,抑菌率最高可达到73.9%;其发酵液可导致镰刀菌孢子膨大变形,菌丝折叠断裂。其最佳发酵条件为:培养时间6 d,温度29～32℃,初始pH 7.2,装液量100 mL/300 mL三角瓶,培养基为改良2号液体培养基。其抑菌活性物质可以被氯仿萃取,并且具有较好的热稳定性,最适pH为7～9。盆栽试验结果表明,GS2-1菌剂对胡麻枯萎病的防效可以达到68.8%。

关键词: 胡麻枯萎病, 拮抗性放线菌, 防治效果

Abstract: In order to get a antagonistic actinomycete against linseed wilt，an actinomycete GS2-1 was isolated from pathogenic soil of linseed，which could inhibit growth of Fusarium oxysporum f． sp． lini． The inhibition rates against 151 fungi isolated from different provinces were evaluated． The fermentation filtrate influencing the mycelium growth and the spore bourgeoning and the optimum fermentation conditions were also conducted． Antagonistic substance was extracted from the fermentation liquid，its activity in lab and antagonistic effects against linseed wilt in control environment were tested． The results showed that GS2-1 had a strong antagonistic effect on those 151 fungi， the highest inhibition rate was 73． 9%． Antagonistic substance of GS2-1 appeared to inhibit pathogens by leading to mycelium rupture，distortion，abnormality，and inhibition bourgeon of spores，and leading to abnormality of spores． And the best fermentation time of GS2-1 was 6 days，the optimum temperature was 29 - 32℃，beginning pH 7． 2，and the optimal pH 7 - 9． The best medium was soybean farina medium (modified) and its volume of 100 mL per 300 mL flask． The antagonistic substance could be extracted by chloroform and has nice thermal stability． The control effect of GS2-1 was as high as 68． 8% in control environment．

Key words: Linseed wilt, Antagonistic actinomycete, Control effect

中图分类号: 

• S565．9

• S482．6