寡雄腐霉发酵液对温室番茄生长及灰霉病的防治作用

Influences of Pythium oligandrum broth on the growth and botrytis control of tomato seedlings in greenhouses

为了研制高效、无毒的生物农药,采用自主分离的寡雄腐霉生防菌株Pythium oligandrum CQ2010制备发酵液,研究其对温室番茄生长及灰霉病的防治作用。结果表明,寡雄腐霉发酵液（Pythium oligandrum broth,POB）能显著提高番茄叶绿素含量,增强根系活力,增加氮、磷、钾吸收,促进植株生长,使生物量比对照提高65.14%;同时能激活与叶片抗病性相关的过氧化物酶和过氧化氢酶活性,诱导植株产生抗病性反应,提高抗病能力,其效果优于寡雄腐霉卵孢子制剂;而且POB能显著抑制离体灰葡萄孢菌的菌丝生长和孢子萌发;施用POB能使番茄灰霉病发病率下降22.28%-31.05%,病情指数从52.5（对照）下降至22.5-27.5,相对防治效果达47.62%-57.14%,叶片丙二醛含量显著降低,说明POB减轻了灰葡萄孢菌对细胞膜的伤害。表明POB兼具促进番茄生长及防治灰霉病的作用。

In order to develop nontoxic and efficient biological pesticides,a pot experiment was carried out to study the effects of fermentation broth produced from a self-isolated Pythium oligandrum（ strain CQ2010） on the growth and botrytis control of tomato seedlings in greenhouses. The results showed that Pythium oligandrum broth（ POB） promoted the growth and increased the biomass of tomato seedlings by65. 14% compared to the control. Similarly,leaf chlorophyll,activities of roots and nitrate reductase,and plant nutrient uptake,including nitrogen,phosphorus and potassium,were increased due to POB application. POB also stimulated the activities of enzymes related to disease resistance, such as peroxidase and catalase,induced plant disease resistance reaction,and raised the ability of disease resistance, and better effects were obtained under POB treatment than P. oligandrum spores.Furthermore,POB inhibited mycelial growth and spore germination of Botrytis cinerea Pers. and lowered the disease incidence of tomato seedlings by 22. 28%- 31. 05% after pathogen inoculation. The disease index fell from 52. 5（ CK） to 22. 5- 27. 5（ POB） and the relative control efficacy reached 47. 62%-57. 14%. Malondialdehyde in the leaves of seedlings infected with pathogen was reduced by POB,suggesting the prevention of cell membrane from harmfulness by pathogenic microbes. The results indicated that POB could promote plant growth and control disease occurrence.