PS04菌株对水稻纹枯病的防效及对水稻2种防御性酶活性的诱导

Biocontrol of PS04 against rice sheath blight and its induced activities to two rice defense enzymes

【目的】研究类芽孢杆菌PS04菌株及其代谢物对水稻纹枯病的预防和治疗效果,探索PS04对水稻纹枯病的防治机理,为PS04菌株生物制剂的研发提供理论依据。【方法】以水稻幼苗为供试材料,用带菌谷粒接种法接种水稻纹枯病菌,分别以PS04菌株发酵液、浓缩液和乙醇粗提物为药剂,保护性试验于接种前24h施药,治疗性试验于接种后24h施药,施药10d后调查统计防效;同时喷施发酵液与接种水稻纹枯菌进行防御性酶诱导试验,分别于接种后1,2,3,5,8d测定水稻叶鞘过氧化物酶(POD)和多酚氧化酶(PPO)活性,并分析其动态变化。【结果】药效试验表明,PS04菌株发酵液兼具保护性和治疗性作用,其防效分别达93.65%和92.02%,经100℃水浴加热后发酵液的防效分别为87.37%和90.28%;PS04浓缩液和乙醇粗提物的保护性和治疗性防效均具有明显的剂量效应,6g/L浓缩液的防效为76.01%和50.74%,9g/L乙醇粗提物的防效69.95%和73.85%。防御性酶活性诱导试验表明,PS04菌液能诱导水稻PPO和POD活性大幅提高,表明PS04发酵液具有良好的抗病性诱导作用。【结论】PS04菌液不仅对水稻苗期纹枯病具有显著的保护性和治疗性,而且还能诱导水稻POD和PPO活性提高,具有很好的开发潜力。

【Objective】 This study focus on the prevention and treatment effect of PS04 and its metabolites against rice sheath blight,and the prevention mechanism of the PS04 on rice.【Method】 With rice seedlings as the material,grain with pathogen for inoculation,spraying was conducted at 24 h before inoculation for the protective test,and at 24 h after inoculation for the therapeutic experiments.10 d later,we investigated the disease level.Spraying fermentation and inoculation were carried out at the same time in the test of induced resistance.The activity of peroxidase（POD） and polyphenol oxidase（PPO） in rice leaf sheath were measured at 1,2,3,5,and 8 d after inoculation and their dynamic change were analyzed.【Result】 Efficacy trials showed that fermentation had good temperature stability,protective and therapeutic effect,and the control effects were 93.65% and 92.02% respectively.The control effects of fermentation heated for 30 min by 100 ℃ water were 87.37% and 90.28% respectively.The concentrated and extract of PS04 all had dose-response in the protective effects and therapeutic effects.The control efficiency of concentrated PS04（6 g/L） were 69.95% and 73.85% respectively while those of extract of PS04（9 g/L） were 69.95% and 73.85% respectively.Induced resistance test indicated that the enzyme POD and enzyme PPO were improved markedly,indicating that PS04 fermentation had good disease resistance induced effect.【Conclusion】 PS04 bacteria fermentation had great protective effect and therapeutic effect against rice sheath blight in seedling stage,and induced the increase of activity of POD and PPO.