Biological Characteristics of the Pathogenic Fungus Causing Stem Bleeding Disease of Coconut

Biological characteristics of C.paradoxa xie331-4 which causing stem bleeding disease of coconut were studied.The results showed that PDA was the optimal medium for mycelia growth and spore germination.The mycelia grew best on media with fructose as C source,and conidia germinated best on media with arabic gum powder as C-source.The mycelia grew best on media with(NH4)2HPO4 as N source and conidia germinated best on media with Peptone as N source.2% Peptone promoted spore germination,but 2% glucose and 2% sucrose inhibited.Temperature ranged from 25 to 35 ℃ was optimal for its mycelia growth and spore germination.Spores could not germinate below 5 ℃ or over 40 ℃.pH ranged from 4 to 11 was optimal for its mycelia growth,while pH7 was optimal for sporulation and 4 for spore germination.Light treatment did not have significant effect on the mycelia growth,while light was good for sporulation.Lethal temperature of the spores was 52 ℃ for 10 minutes.