棘孢木霉菌株PZ6对香蕉促生效应及枯萎病室内防效的影响

【目的】研究棘孢木霉菌株PZ6对香蕉植株促生效应、抗氧化酶活性及枯萎病菌室内防效的影响,为香蕉枯萎病的防控及PZ6菌株的合理开发利用提供理论依据。【方法】以清水为对照(CK),分别设PZ6孢子液与枯萎病菌菌液(FOC4)5个不同组合处理:(1)PZ6;(2)PZ6+FOC4;(3)PZ6(3 d)+FOC4;(4)FOC4(3 d)+PZ6;(5)FOC4,采用盆栽伤根淋灌法,于6~7叶期对香蕉苗根际进行接种处理;不同时期调查不同处理香蕉苗植株性状,测定香蕉苗根系活力及叶片超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性;通过解剖球茎考察病情指数,评价PZ6对枯萎病的室内防效。【结果】与其他处理相比,单施PZ6菌液处理可极显著提高香蕉苗新增株高和根系活力(P0.01,下同),两者分别为6.33 cm和487.43μg TTF/g·h;与FOC4处理相比,配施PZ6菌液的FOC4菌液处理也可极显著提高香蕉苗根系活力。接种FOC4菌液50 d后,不同处理香蕉苗球茎枯萎病发病指数和防治效果均以PZ6(3 d)+FOC4处理表现最佳,其病情指数为37.50,防治效果为48.28%,其次为PZ6+FOC4处理,而FOC4(3 d)+PZ6处理表现较差。处理45 d后,除PZ6处理与CK间的叶片POD活性无显著差异(P0.05)外,不同处理的香蕉苗叶片SOD、POD和CAT活性均与CK间呈极显著差异;除CK外,不同处理间不同酶活性呈一定的变化规律。叶片SOD活性与根系活力表现相似,均以PZ6处理最高(423.71 U/g FW·h),其次为PZ6(3 d)+FOC4、PZ6+FOC4、FOC4(3 d)+PZ6和FOC4处理;叶片POD活性表现相反,以FOC4处理最高(355.07 U/g·min),比对照极显著增加82.33 U/g·min,以处理PZ6最低(273.84 U/g·min)。【结论】棘孢木霉PZ6菌株可在一定程度上提高香蕉苗对枯萎病菌的防御能力,提前施用PZ6菌株可有效阻止病原菌FOC4侵入香蕉苗,延缓植株发病。

Growth-promoting effects of Trichoderma asperellum strain PZ6 on banana and its indoor control effect against banana fusarium wilt

Objective]The present study investigated effects of Trichoderma asperellum strain PZ6 on banana growth promoting, antioxidase activities and indoor control effect of fusarium wilt, in order to provide references for prevention and control of fusarium wilt and development of strain PZ6. Method]Taking clear water as control(CK), five different combi-nations involving PZ6 spore liquid and Fusarium oxysporum f. sp. cubense liquid(FOC4) were set:(1)PZ6,(2)PZ6+FOC4,(3)PZ63d+FOC4,(4)FOC43d+PZ6 and (5)FOC4. Inoculation at banana rhizosphere was conducted at 6-7 leaf stage using root-injury irrigating method. The plant traits in different treatments at different stages were measured , including root activity, superoxide dismutase(SOD) activity, catalase(CAT) activity and peroxidase(POD) activity. The corms were dis-sected to check disease index, so as to evaluate indoor control effects of PZ6 on fusarium wilt. Result]Compared to other treatments, PZ6 treatment could significantly enhance plant height increment(6.33 cm) and root activity(487.43μgTTF/g·h)of banana seedlings(P<0.01, the same below). Compared with FOC4 treatment, FOC4 combined with PZ6 solution could significantly enhance root activity. After 50 days of FOC4 inoculation, the plants treated with PZ6(3 d)+FOC4 showed the best performance in disease index(37.50) and control effect(48.28%), followed by PZ6+FOC4 treatment. The performances were the worst in FOC4(3 d)+PZ6. After 45 days of treatment, excepting for POD activity between treatment PZ6 solution and CK, significant difference(P<0.05) in different treatments between CK were found in SOD, CAT and POD activities in leaf. Excepting for CK, SOD, CAT and POD activities showed certain variation regularity among different treatments. The changing trend of SOD activity was similar to root activity, the highest one was found in treatment PZ6(423.71 U/gFW·h), followed by PZ6(3 d)+FOC4, PZ6+FOC4, FOC4(3 d)+PZ6 and FOC4. The performance of POD activity was on the con-trary, the highest one was found in treatment FOC4(355.07 U/g·min), increasing by 82.33 U/g·min compared to CK, and the lowest one was found in PZ6 solution(273.84 U/g·min). Conclusion]The isolated T. asperellum strain PZ6 can enhance the defensive capability of banana seedlings against FOC4 at certain degree. Applying PZ6 solution in advance can prevent invasion of FOC4 to banana seedlings and delay the occurrence of fusarium wilt.