生姜茎基腐病病原鉴定及甲壳胺对其病原菌的抑菌作用

通过形态学观察、致病性测定及序列分析,对生姜茎基腐病病原菌进行鉴定;并采用菌丝生长速率法、活体组织法和田间试验研究甲壳胺对生姜茎基腐病病原菌的抑菌活性。结果表明,生姜茎基腐病病原菌为群结腐霉(Pythium myriotylum)、刺腐霉(Pythium spinosum)和林栖腐霉(Pythium sylvaticum)。甲壳胺对3种腐霉菌均有抑制作用,抑制中浓度(EC_(50))分别为422.711 2、401.699 5、446.910 7μg·m L~(-1)。显微观察显示,甲壳胺处理后的腐霉菌丝膨大、扭曲,分枝增多,菌丝内部出现空泡化。活体组织法试验结果表明,甲壳胺可以明显抑制生姜茎基腐病的发生。田间防治试验结果表明,甲壳胺可以明显预防生姜茎基腐病的发生,从而提高生姜产量。

Identification of Rhizome Rot Disease Pathogen in Ginger and Chitosan Antifungal Effect on Pathogen

This paper carried out identification on pathogen of rhizome rot disease in ginger by morphological observation，pathogenicity test and sequence analysis；and studied the antifungal activity of chitosan against ginger rhizome rot disease by mycelium growth rate method，in vivo biospy and field experiment. The results showed that the pathogen of ginger rot disease was identified as Pythium myriotylum，Pythium spinosum and Pythium sylvaticum，the mycelial growth of those pathogens were restrained by chitosan and the EC₅₀ values were 422.711 2，401.699 5，446.910 7 μg·mL^-1，respectively. Micrography observation showed，while inoculated in the substrate with chitosan，the mycelia would abnormally grow，like：bulging，contorting，having more branches，and vacuolation appearing inside of mycelia. These results showed that chitosan could obviously inhibit the occurrence of rhizome rot disease in ginger. The results of field control experiment showed that chitosan could significantly prevent the occurrence of rhizome rot disease in ginger，and consequently improve the ginger yield.