堆肥提取液诱导草莓对黄萎病抗性及抑菌机理研究

Induced Resistance in Strawberry against Verticillium Wilt by Compost Tea and Its Inhibition Mechanism

为了明确菌糠堆肥提取液的生物防治效果,进一步探讨其抑菌防病机理,以便于有针对性地利用堆肥提取液达到防病、治病的效果。采用体内和体外2种试验方法,以草莓黄萎病菌为靶标病原菌,研究了堆肥提取液原液、高温灭菌液和过滤除菌液对大丽轮枝菌菌丝生长和分生孢子萌发的抑制作用,通过温室盆栽试验验证其对草莓黄萎病的防病促生效果,并测定根施堆肥提取液对草莓叶片内防御酶系的影响。研究表明,堆肥提取液对病原菌菌丝生长和分生孢子萌发均有显著的抑制作用,抑制率分别为92.43%和82.94%,经高温灭菌和过滤除菌后抑制效果显著降低。盆栽试验结果表明,预先用堆肥提取液灌根处理对草莓黄萎病的防治效果高达42.23%,且能诱导草莓叶片内防御酶活性显著增强,接病原菌后第6 d该处理下的POD和PPO活性分别比施清水对照提高了45.45%和39.47%,而MDA含量则下降了14.83%。说明微生物对病原菌的直接抑制作用以及诱导系统抗性是菌糠堆肥提取液发挥抑菌防病功效的主要因素。

We investigated the biocontrol potential of the tea produce from spent mushroom substrate compost for the control of strawberry Verticillium wilt caused by Verticillium dahliae, which is in order to make target use of compost tea to the achievement of disease prevention and treatment. In vitro and in vivo experiments were carried out to determine the mechanisms involved in suppression of V. dahliae. Non-sterilized, heat-sterilized and filter-sterilized compost teas were tested on the inhibition of mycelial growth and conidial germination of V. dahliae. Glasshouse trials were conducted to evaluate the control efficiency of compost tea against strawberry Verticillium wilt and plant growth-promoting effect, and to test for the ability of the compost tea to induce the production of defense-related enzymes. The highest percentage of inhibition in mycelial growth and conidial germination was obtained by the non-sterilized compost tea with values of 92.43% and 82.94%, respectively. The inhibitory efficacy was reduced significantly when the tea was heat-sterilized or filter-sterilized. Pot tests indicated that the control effect of Verticillium wilt was 42.23% when strawberry plants were pre-treated with compost tea. There was a significant increase in defense enzymes when the pre-treated strawberry plants were challenged with V. dahliae. The activities of POD and PPO were increased by 45.45% and 39.47% respectively as compared with the control, while the content of MDA decreased by 14.83% on the sixth day after inoculation. It was therefore suggested that the SMS compost tea suppress pathogen through direct inhibition of microorganisms and primed systemic resistance.