两种海洋寡糖对植物病原真菌的抑制作用

在马铃薯葡萄糖琼脂(PDA)培养基上,采用生长速率法研究了两种海洋寡糖(壳寡糖Ⅰ、卡拉胶寡糖)对水稻稻瘟菌Pyricularia oryzae、棉花黄萎菌Verticillium dahliae、小麦赤霉菌Fusarium graminearum和番茄灰霉菌Botrytis cinerea的体外抑菌作用。结果表明,聚合度为2~20的壳寡糖Ⅰ对供试的4种植物病原真菌均有一定的抑制作用,抑制强度随壳寡糖Ⅰ浓度的升高而增强,壳寡糖Ⅰ可明显抑制番茄灰霉菌菌丝的生长(EC50=680 mg/L)和孢子的萌发(EC50=162 mg/L);而聚合度低的壳寡糖Ⅱ(聚合度为2~10)对番茄灰霉菌菌丝的生长抑制作用较低;卡拉胶寡糖对3种植物病原真菌菌丝的生长不仅没有抑制作用,反而对水稻稻瘟菌和番茄灰霉菌菌丝的生长有明显促进作用。

Antifungal activity of two marine oligosaccharides to phytopathogens in vitro

Two marine oligosaccharides,oligochitosan and oligocarrageenan,were evaluated for antifungal activity on mycelial growth of four phytopathogens including Pyricularia oryzae,Verticillium dahliae,Fusarium graminearum and Botrytis cinerea on potato dextrose agar(PDA) in vitro.A strong antifungal activity on mycelial growth and spore germination of Botrytis cinerea with EC50 values of 680 mg/L and 162 mg/L was observed in oligochitosan.Oligochtiosan with a degree of polymerization from 2 to 20 showed higher antifungal activity on mycelial growth of Botrytis cinerea than oligochtiosan with a degree of polymerization from 2 to 10.In contrast,oligocarrageenan had no antifungal activity on the tested phytopathogens instead of improvement of mycelial growth in Pyricularia oryzae and Botrytis cinerea.