2株木霉抑菌效果及其促植物生长机制

Antifungal effect and plant growth promoting mechanism of two Trichoderma strains

【目的】探究绿色木霉(Trichoderma viride)和棘孢木霉(T. asperellum)对8种植物病原菌的抑制效果及其促植物生长机制,为木霉防治植物病害和促进植物生长等的田间应用提供理论参考。【方法】采用平板对峙法和固体稀释法,检测2株木霉及其活性代谢产物对8种植物病原菌(棉花枯萎病菌、茄子菌核病菌、番茄链格孢病菌、茄腐镰刀病菌、尖孢镰刀病菌、枸杞炭疽病菌、番茄灰霉病菌和番茄匍柄霉病菌)的抑制率;采用平板透明圈法、Salkowski比色法及钼锑抗比色法测定2株木霉的生防因子、生长素及溶磷效果;通过辣椒盆栽试验,测定2株木霉发酵液不同稀释倍数处理对辣椒叶片叶绿素含量及3种抗性酶[过氧化物酶(POD)、多酚氧化酶(PPO)和苯丙氨酸解氨酶(PAL)]活性的影响。【结果】平板对峙试验结果显示,2株木霉对8种植物病原菌的抑菌率均在60.00%以上;绿色木霉发酵11 d时其无菌滤液对茄子菌核病菌的抑制率达96.78%,但对其他病原菌的抑制率不高;棘孢木霉发酵11 d时无菌滤液对茄子菌核病菌、枸杞炭疽病菌和番茄链格孢病菌的抑制效果较好,抑菌率分别为99.08%、85.33%和68.65%,发酵9 d时无菌滤液对番茄灰霉病菌的抑制率为72.08%;2株木霉均可产生蛋白酶、几丁质酶、纤维素酶和铁载体4种生防因子;绿色木霉发酵9 d时分泌吲哚乙酸(IAA)量为3.389 mg/L,在PKO无机磷液体培养基培养7 d后溶磷量为67.236μg/m L;棘孢木霉发酵11 d时分泌IAA量达11.638 mg/L,在PKO无机磷液体培养基培养7 d后溶磷量达151.905μg/m L;盆栽试验结果表明,喷施不同稀释倍数的棘孢木霉发酵液较绿色木霉发酵液更能提高辣椒叶片叶绿素含量及3种抗性酶活性。【结论】供试2株木霉对8种植物病原菌均具有抑制能力并存在多种生防因子和促植物生长能力,其中棘孢木霉较绿色木霉具有更好的抑菌和促进植物生长及提高植物叶片叶绿素含量和抗性酶活性的能力,具有较好的田间应用潜力。

【Objective】To explore the inhibitory effect of Trichoderma viride and T.asperellum on eight plant pathogens and the mechanism of promoting plant growth so as to provide theoretical reference for their field application in preventing and controlling plant diseases and promoting plant growth.【Method】The inhibition rates of two Trichoderma strains and its active metabolites against eight plant pathogens(Fusarium oxysporum f.sp.vasinfectum,Sclerotinia sclerotiorum,Alternaria solani,F.solani,F.oxysporum,Colletotrichum gloeosporioides,Botrytis cinerea,Stemphylium lycopersici)were detected by plate confrontation method and solid dilution method.The biocontrol factors,auxin and dissolved phosphorus of two Trichoderma strains were determined by plate transparent ring method,Salkowski colorimetric method and molybdenum-antimony colorimetric method.The content of chlorophyll and activities of peroxidase(POD),polyphenol oxidase(PPO)and phenylalaninammo-nialyase(PAL)in the leaves were measured by pot pepper experiment before and after treatment with different dilutions of the two Trichoderma fermentation broths.【Result】The results of the plate confrontation test showed thatthe inhibitory rate of the two Trichoderma strains on eight plant pathogens was more than60.00%.When the T.viride was fermented for 11 d,the inhibition rate of the sterile filtrate against the Sclerotinia sclerotiorum reached 96.78%,and the inhibition rate against other pathogens was not high.The sterile filtrate of T.asperellum fermented for 11 d had inhibition on the pathogen of S.sclerotiorum,C.gloeosporioides and A.solani,which were 99.08%,85.33%,and 68.65%,respectively,and the inhibition rate of sterile filtrate on B.cinerea was 72.08%after fermentation for 9 d.Two Trichoderma strains could produce protease,chitinase,cellulase,siderophore.The content of indole-3-acetic acid(IAA)reached 3.389 mg/L when fermentation for 9 d by T.viride,while the content of IAA was 11.638 mg/L at 11 d by T.asperellum.After being cultured in PKO inorganic phosphorus liquid medium for 7 d,the dissolved phosphorus amount of the two Trichoderma strains was 67.236 and 151.905μg/m L,respectively.The pot experiment showed that the treatment of T.asperellum fermentation broth could increase the chlorophyll content and three resistant enzyme activities of pepper leaves more than T.viride.【Conclusion】Two Trichoderma strains have the ability to inhibit eight plant pathogens and there are multiple biocontrol factors and can promote plant growth.Among them,T.asperellum has the better ability of bacteriostasis,promoting plant growth and increasing chlorophyll content and resistance enzyme activity in plant leaves than T.viride.It proves that T.asperellum has good development potential in field application.