微黄青霉ZF1及其代谢产物对禾谷镰孢的抑菌活性

【目的】对前期从土壤中筛选获得的1株具有生防效果的微黄青霉(Penicillium minioluteum)ZF1,进一步分析其对禾谷镰孢(Fusarium graminearum)的抑菌效果,以及其培养滤液与化学药剂混配的抑菌能力和对玉米叶片、籽粒的侵染能力,明确该生防菌的开发利用价值,为防治禾谷镰孢引起的玉米茎腐病和穗腐病提供依据。【方法】采用菌丝生长速率法测定微黄青霉ZF1对禾谷镰孢的抑菌能力,微黄青霉ZF1培养滤液对禾谷镰孢的抑菌作用;通过玻璃纸法测定微黄青霉ZF1次生代谢产物对禾谷镰孢菌落生长的影响;比较咯菌腈、微黄青霉ZF1菌株培养滤液及咯菌腈和培养滤液混配3个处理对禾谷镰孢菌丝生长的抑制作用;分别在5叶期和乳熟期检测微黄青霉ZF1对玉米叶片和籽粒的侵染能力。【结果】微黄青霉ZF1能够明显抑制禾谷镰孢生长,抑制作用达到81.33%,抑菌面积为16.21 cm2;去玻璃纸PDA培养基上,ZF1菌株次生代谢产物对禾谷镰孢生长的抑制作用达到55.46%;菌株培养滤液稀释10、20、50和100倍后对禾谷镰孢菌抑制作用分别为81.04%、64.46%、22.67%和1.12%,但微黄青霉培养滤液对禾谷镰孢菌丝形态影响不明显;咯菌腈和微黄青霉菌培养滤液复配后对禾谷镰孢的抑制作用比二者单独使用有所增强,咯菌腈抑制禾谷镰孢菌丝生长的EC50和EC95值分别为0.0162和0.5287μg·m L-1;10%微黄青霉菌培养滤液和0.5μg·m L-1咯菌腈对禾谷镰孢的抑制率分别为86.45%和95.13%,二者复配后降低了对禾谷镰孢菌丝生长的EC50和EC95值,延长了作用时间,EC50和EC95值分别为0.0023和0.4011μg·m L-1,培养4 d后咯菌腈抑菌作用丧失,而0.5μg·m L-1咯菌腈与10%微黄青霉菌培养滤液复配后较0.5μg·m L-1咯菌腈单独作用时间延长了10 d。接种微黄青霉至玉米叶片和受伤的玉米籽粒,仅在叶片表面和伤口处产生微寄生霉层。【结论】微黄青霉ZF1菌株及其培养滤液对禾谷镰孢均有明显的抑制作用,咯菌腈和培养滤液复配对禾谷镰孢的抑制作用优于单独使用咯菌腈的处理。研究结果可为微黄青霉菌的开发应用提供依据,为禾谷镰孢茎腐病和穗腐病的防治开辟新途径。

Antifungal Activities of Penicillium minioluteum ZF1 and Its Metabolites to Fusarium graminearum

【Objective】 Penicillium minioluteum ZF1 was isolated from the soil and identified as having the effect of biological control in previous studies. The objective of this study is to analyze the inhibition effect of the isolate and its culture filtrate with chemical fungicide to Fusarium graminearum, clarify the value of ZF1, and to offer a novel method for controlling the stalk rot and ear rot which are caused by F. graminearum. 【Method】 F. graminearum was inoculated at the mixed PDA and the growth speed was calculated. The effect of secondary metabolites on control of the mycelial growth of F. graminearum was known when cellophane removed and F. graminearum was inoculated. Fludioxonil, ZF1 culture filtrate and the two mixtures were compared each other, and their EC₅₀ and EC₉₅ were measured. The leaves at 5-leaf stage and kernels at milk-ripe stage were inoculated with P. minioluteum, and the process was observed. 【Result】 P. minioluteum ZF1 could obviously inhibit the mycelial growth of F. graminearum. The inhibition ratio reached 81.33%. The area of inhibited mycelial growth of F. graminearum was 16.21 cm² compared with the control groups. The effect of secondary metabolite of P. minioluteum was inoculated on PDA plate removed cellophane which inhibited the mycelia growth of F. graminearum reached 55.46%. The filtrate of P. minioluteum which were diluted 10, 20, 50 and 100 folds inhibited the growth area of mycelia of F. graminearum were 81.04%, 64.46%, 22.67% and 1.12%, respectively. The mycelia of morphology were not changed when ZF1 culture filtrate was added in PDA. The mixture of fludioxonil and 10% culture filtrate of P. minioluteum had the better effect than each single. The EC50 and EC95 values of fludioxonil to F. graminearum were 0.0162 and 0.5287 μg·mL^-1, respectively. The inhibition ratios of 10% culture filtrate of P. minioluteum and 0.5 μg·mL^-1 fludioxonil were 86.45% and 95.13%, respectively. EC₅₀ and EC₉₅ values of the two mixtures were 0.0023 and 0.4011 μg·mL^-1. The effect of fludioxonil inhibition was lost after 4 days. The inhibition effect of the mixture of 0.5 μg·mL^-1 fludioxonil and 10% culture filtrate of P. minioluteum prolonged for 10 days compared with only 0.5 μg·mL^-1 fludioxonil. Slight mold appeared in injured maize kernels and seedling leaves when P. minioluteum was inoculated on them. 【Conclusion】 The inhibition effect of P. minioluteum ZF1 and its culture filtrate on F. graminearum was obvious. The mixture of fludioxonil and culture filtrate of P. minioluteum could prolong the inhibition time to the mycelial growth of F. graminearum. A novel method that P. minioluteum acts as a biocontrol fungus for controlling maize stalk rot and ear rot can be used in the future.