烟管菌M-1对小麦苗期赤霉病的防效及其生理生化机制分析

为研制高效的生物农药,利用自主分离的烟管菌Bjerkandera adusta生防菌株M-1,通过平板对峙试验和温室盆栽生防试验研究其对小麦苗期赤霉病的防效及其生理生化机制。结果表明,菌株M-1及其发酵液对小麦赤霉病致病菌禾谷镰孢菌Fusarium graminearum的抑制率分别为57.71%和72.95%;且均能降低小麦赤霉病的发病率和病情指数,防效分别为88.10%和77.18%,与化学药剂多菌灵的防效相当;同时使与抗病性相关的叶片超氧化物歧化酶活性较对照分别提高了35.37%和29.09%,过氧化氢酶活性提高了87.51%和25.15%,过氧化物酶活性提高了43.95%和38.74%,苯丙氨酸解氨酶活性提高了40.74%和7.82%,可诱导植株产生抗病反应,提高抗病能力;也使细胞膜透性分别降低了35.94%和32.15%,丙二醛含量降低了41.76%和3.23%,能减轻病菌对细胞膜的伤害;并能增加叶绿素含量和硝酸还原酶活性,提高N、P、K的含量及吸收量,使株高较对照分别增加了13.33%和8.31%,生物量增加了34.45%和17.59%。表明菌株M-1对小麦苗期赤霉病有较好的防效,不仅能提高小麦幼苗的抗病能力,还能促进其生长。

Analysis of the control effect of biocontrol fungus strain Bjerkandera adusta M-1 on wheat seedling scab and its physiological and biochemical mechanism

In order to develop efficient biological pesticides, the self-isolated biocontrol strain Bjerkandera adusta M-1 was used to study its control effect on wheat seedling scab and physiological and biochemical mechanisms by using confrontation culture and greenhouse pot experiments. The results showed that strain M-1 and its fermentation broth inhibited the growth of Fusarium graminearum, with an inhibition rate of 57.71% and 72.95%, respectively; moreover, both reduced the incidence and disease index of scab, and the control effect reached 88.10% and 77.18%, respectively, equivalent to the effect of chemical pesticide carbendazim. Besides, strain M-1 and its fermentation broth increased the enzyme activity related to disease resistance in leaves, such as superoxide dismutase (by 35.37% and 29.09%), catalase (by 87.51% and 25.15%), peroxidase (by 43.95% and 38.74%), and phenylalanine ammonia-lyase (by 40.74% and 7.82%), inducing plant to produce disease resistance reaction and raise the ability of disease resistance. In addition, strain M-1 and its fermentation broth decreased the cell membrane permeability (by 35.94% and 32.15%) and malondialdehyde content (by 41.76% and 3.23%), reducing damage to cell membranes by pathogenic fungi. Meanwhile, strain M-1 and its fermentation broth improved the chlorophyll content and nitrate reductase activity, promoted nitrogen, phosphorus, potassium content and absorption, and increased the plant height (by 13.33% and 8.31%) and biomass (by 34.45% and 17.59%). The results suggested that strain M-1 had a good control effect on wheat seedling scab, and could not only improve the disease resistance of wheat seedlings, but also promote their growth.