【摘要】 为了对松萎蔫病进行安全、无污染的生物防治,从青岛大学校园内采集的样品中分离出120株菌。采用浸渍法从中筛选出1株具有较高杀线虫活性的细菌G8-1。杀线虫活性测定结果表明,该菌株发酵上清液48 h后的杀线虫率为90.81%。通过16S rRNA的序列分析,将其鉴定为Flectobacillus rhizosphaerae。通过单因素分析法和正交实验对该菌株的培养条件进行研究,确定最佳培养条件:最适初始pH为8.0,最适培养温度为35℃,最佳接种菌龄为9 h,最佳培养时间为3 d,菌株G8-1发酵上清液的杀线虫率可达到96.31%。对菌株产生的活性物质的稳定性进行初步分析,结果表明该菌株的活性物质都具有较好的热稳定性,并且在弱碱性条件下具有较高的杀线虫活性稳定性。本研究为松材线虫的生物防治提供参考。更多还原

【Abstract】 In order to implement safety and pollution-free biological control on pine wilt, a total of 120 strains of bacteria were isolated samples collected from the campus of Qingdao University. One strain of bacteria G8-1 with high nematicidal activity was screened by immersion method. The results of nematicidal activity showed that the rate of nematodes was at 90.81% by fermented supernatant 48 h after. It was identified as Fecmumillus rhizosphaerae by sequence analysis of 16 S rRNA. Using single factor analysis method and orthogonal experiment the culture conditions of the strain and the optimum culture conditions were studied and determined, the optimal initial was at pH 8.0, the optimal temperature at 35 ℃, the best inoculation strain age was 9 h, the best cultivation time was 3 d, the nematicidal rate of the fermentation supernatant of strain G8-1 was as high as 96.31%. The stability of the active substances produced by the strain was initially analyzed, and the results showed that the active substances produced by the strain had better thermal stability and higher activity stability against nematodes under weakly alkaline conditions. This paper provided reference for bio-controlling pine nematode.更多还原