几丁寡糖对烟草黑胫病的控制效应及其机制

在室内条件下,采用菌丝生长速率法测定了几丁寡糖对烟草黑胫病菌的抑制作用,继而在温室盆栽和人工接种条件下,分别测定几丁寡糖、木霉、几丁质、几丁寡糖+木霉、几丁寡糖+木霉+几丁质等5种处理对烟草黑胫病的防治效果。结果表明,几丁寡糖在离体条件下对烟草黑胫病菌菌丝生长无抑制作用,但在盆栽试验中对烟草黑胫病具有显著防治效果。5种处理中,几丁寡糖单独处理对烟草黑胫病的防治效果最高,为57.81%,其次为几丁寡糖+木霉+几丁质和几丁寡糖+木霉处理,分别为53.49%和52.49%。在温室条件下对烟草植株施用几丁寡糖及人工接种黑胫病菌后10天内,几丁寡糖能显著提高烟草体内的SOD、POD、PPO和几丁质酶活性,且活性峰值分别比对照提高96.30%、136.36%、10.34%和9.10%。

Control effectiveness and mechanism of chitinooligosaccharide on tobacco black shank

The inhibition of chitinooligosaccharide (COS) against Phytophthora nicotianae var. nicotianae and the control effectiveness of COS on tobacco black shank caused by the oomycete were investigated in this paper. And the dynamic activities of superoxide dismutase (SOD), peroxidase (POD), polyphenol oxidase (PPO), phenylalanine ammonialyase (PAL) and chitinase in the tobacco plants treated with COS were measured to explore the mechanism in bio-control effects of COS on the disease. The results showed that in vitro, COS had not inhibition against the mycelium growth of P.nicotianae var. nicotianae on lima bean agar. However, on the condition of artificial inoculation and pot cultivation in greenroom, COS and its combination were effective for the control of the disease, and the control effectiveness was 57.81% in the treatment with COS solely. Next were the control effectiveness of Trichoderma+COS+chitin and COS+Trichoderma in which the effectiveness were 53.49% and 52.49%, respectively. The results of enzyme activity tests showed that COS enhanced activities of SOD, POD, PPO and chitinase in tobacco plants in 10 days after treatment in greenroom, with the peak values increased by 96.30%, 136.36%, 10.34% and 9.10% compared to the control respectively, which was consistent with the result of the control test. The results suggested that COS had biological activity to induce and improve resistance of tobacco plants to black shank, with considerable potential in control of the destructive tobacco disease.