寡雄腐霉发酵液对烤烟生长的影响及对烟草黑胫病的防治作用

Effects of the fermentation broth of Pythium oligandrum on the growth and black shank control of flue-cured tobacco

为了探索对烟草黑胫病高效、稳定的生防制剂,利用寡雄腐霉工程菌株制备发酵液,采用温室盆栽试验研究该发酵液对烟苗生长的影响和对烟草黑胫病的防治作用。寡雄腐霉发酵液可提高正常烟苗生物量达22.6%,促进烟苗氮、磷、钾吸收;带病烟苗的发病率和病情指数分别降低了61.6%和64.2%,相对防治效果达64.2%;施用发酵液明显降低带病烟苗的细胞膜透性和丙二醛含量,提高烟叶多酚氧化酶、超氧化物歧化酶和苯丙氨酸解氨酶活性。说明寡雄腐霉发酵液可诱导烟株的防御作用,并提高其抗病能力和促生作用。

In order to explore a high-effective and stable biocontrol agent for controlling black shank of flue-cured tobacco, a greenhouse pot experiment was carried out to study the effects of the fermentation broth of Pythium oligandrum from France on the growth and black shank control of flue-cured tobacco seedlings. The results showed that seedling biomass was increased by 22.6% and nutrient absorptions （nitrogen, phosphorus and potassium） were promoted significantly after using fermentation broth com- pared to the blank control （without fermentation broth supply）. In contrast, the disease incidence and index were reduced by 61.6% and 64.2% with fermentation broth supply under pathogen inoculation, respectively, leading to 64.2% of the relative control efficacy. Meanwhile, fermentation broth supply de- creased both malondialdehyde and cell membrane permeability remarkably in the infectious seedlings, but stimulated the activities of enzymes related to disease defense like polyphenol oxidase, superoxide dis- mutase and phenylalanine ammonialyase in leaves. Therefore, the fermentation broth could induce dis- ease defense responses, increase resistant disease abilities, and promote seedlings growth.