南极菌B-3胞外寡聚糖对黄瓜的诱导抗病作用

目的]研究南极菌B-3对黄瓜的诱导抗病作用。方法]以黄瓜幼苗为材料,研究南极菌B-3胞外寡聚糖的分子量、单糖组成,及对黄瓜叶中防御酶的诱导作用与黄瓜白粉病的诱导抗病性。结果]B-3胞外寡聚糖经高效凝胶渗透色谱测定其分子量为2112D,气相色谱分析由甘露糖和葡萄糖2种单糖组成;0.3%、0.5%和0.8%的B-3胞外多糖分别对黄瓜幼苗喷施不同时间后,黄瓜体内的几丁质酶,β-1,3-葡聚糖酶,苯丙氨酸解氨酶（PAL）,过氧化物酶（POD）的活性均较对照有不同程度的提高,且与0.5%的壳聚糖具有相似的诱导效果;同时,0.5%的B-3多糖能够显著地降低黄瓜白粉病的病情指数,防效达24.49%。结论]B-3寡聚糖有望开发为新型抗病诱导子。

Induced Resistance against Cucumber by Antarctic Bacterium Psychrobacter sp. B-3 Oligosaccharides

Objective]The aim was to study the induction and resistant effect of antarctic bacterium Psychrobacter sp.B-3 oligosaccharides against cucumber.Method]The molecular weight,sugar composition,induced resistance against powdery mildew and defense enzymes activities related to resistance in cucumber seedlings treated with self-developed Antarctic bacteria B-3 extracellular oligasaccharides were studied.Result]The molecular weight of B-3 extracellular oligasaccharides was determined as 2 112 D by the HPLC method,sugar composition revealed that main structure of B-3 was mannose and glucose;the activities of chinitase,β-1,3-glucanse,phenylanine,ammonialyse(PAL),superoxide dismutase(SOD),and peroxidase(POD) in cucumber seedlings stimulated by B-3 increased apparently at different times compared with untreated plants,and B-3 has a similar induction effects with 0.5% of the chitosan; at the same time,0.5% of the B-3 polysaccharide significantly reduced the disease index of cucumber powdery mildew,anti-efficiency reached 24.49%.Conclusion]B-3 polysaccharide is expected to develop as a new type of resistance elicitor.