【摘要】 报道3种化学合成的寡糖(β-1,3-乙酰氨基葡聚二糖,β-1,3-乙酰氨基葡聚三糖和Lewis~a三糖)诱导黄瓜对镰孢霉枯萎病(Fusariumoxysporumf.sp.cucumerium)的抗性.在黄瓜胚根期,β-1,3-乙酰氨基葡聚二糖和β-1,3-乙酰氨基葡聚三糖浸泡种子胚根后,表现抗病性,相对诱导抗性效果分别为21.9和22.3,β-1,3-乙酰氨基葡聚糖的最低有效诱导浓度为5μg·mL-1;而Lewis~a三糖处理不表现抗病性.在黄瓜幼苗期,用β-1,3-乙酰氨基葡聚二糖和β-1,3-乙酰氨基葡聚三糖叶面喷雾,均表现抗病性,相对诱导抗性效果分别是28.5和23.5,β-1,3-乙酰氨基葡聚糖的最低有效诱导浓度为10μg·mL-1;而Lewis~a三糖同样处理后不表现抗性.化学合成的几丁寡糖类似物(β-1,3-乙酰氨基葡聚二糖和β-1,3-乙酰氨基葡聚三糖)和Lewis~a三糖诱导黄瓜抗性的差异可能是由于糖残基、还原末端取代基及(或)其主链结构的差异.更多还原

【Abstract】 Induced resistance of cucumbers to Fusarium wilt disease by three synthesized oligosaccharides: β-1,3-N-acetyl-glucosamine disaccharide, β-1,3-N-acetyl-glucosamine trisaccharide and Lewisa trisaccharide was investigated. In radicle phase, after the roots were soaked with β-1,3-N-acetyl-glucosamine disaccharide and β-1, 3-N-acetyl-glucosamine trisaccharide solution, the cucumbers showed resistance to the wilt disease with relative induced efficiencies of 21.9 and 22.3, respectively; the effective induced concentration of β-1,3-N-acetyl-glucosamine oligosaccharides was at least 5 μg·mL -1 . In cucumber seedling phase, the plants treated with β-1,3-N-acetyl-glucosamine disaccharide and β-1,3-N-acetyl-glucosamine trisaccharide solution by foliar spraying also showed resistance to the wilt disease with relative induced efficiencies of 28.5 and 23.5, respectively; the effective induced concentration of β-1,3-N-acetyl-glucosamine oligosaccharides was at least 10 μg·mL -1 . However, in both growth phases, after the plants were treated with Lewisa trisaccharide by the same way mentioned above,they showed no resistance to the wilt disease. The cucumber resistant differences of N-acetylchitooligosaccharide analogues (β-1,3-N-acetyl-glucosamine disaccharide and β-1,3-N-acetyl -glucosamine trisaccharide) and Lewisa trisaccharide may be caused by the differences of the sugar residues, the substituents on the reducing terminal residue or (and) the oligosaccharide backbone structures.更多还原