油棕草茎点霉叶斑病病原菌的生物学特性和毒力测定

Biological Characteristics and Toxic Test of the Pathogen(Phoma herbarum) of Oil Palm Leaf Spot in the Seedling Stage

对油棕草茎点霉叶斑病病原菌(Phoma herbarum)的生物学特性展开研究。结果表明:菌丝最适生长温度为20~25℃,p H为6~8,在PDA和PSA培养基中菌丝生长最快,光照对菌丝生长无影响,菌丝可利用多种碳源、氮源,其中以葡萄糖、半乳糖、木糖和蔗糖为碳源生长最好,对氮源的利用效率以胰蛋白胨最高。采用菌丝生长速率法测定13种杀菌剂的室内毒力,结果表明:甲基硫菌灵和咪鲜胺毒力最强,EC50分别为1.100 7、1.451 6 mg/L,效果最好。

The biological characteristics of Phoma herbarum, which causes leaf spot on oil palm, were as follows：the optimum temperature and p H for the mycelia growth was 20~25 ℃ and p H 6.0~8.0, respectively. The hyphae of this strain could grow faster on PDA and PSA medium and there was no significance between the light or dark treatments. Besides, the carbon sources such as glucose, galactose, xylose and sucrose were suitable for the hyphae to grow and tryptone could be efficiently used by this strain. Lastly, the inhibition activity of 13 common fungicides against P. herbarum was also carried out by the mycelium growth rate method. According to the tested results, the fungicides with best inhibition activity were 70% Thiophanate-Methyl（ WP） and 45% Prochloraz（ SC） and the values of their EC50was1.100 7 and 1.451 6 mg/L, respectively.