橡胶树灵芝茎腐病病原菌鉴定及其生物学特性测定

Identification and Biological Characteristics of Pathogen of Ganoderma Causing Stem Rot on Hevea brasiliensis

在海南省澄迈等地的橡胶树林地发现一种新的茎腐病,由灵芝属的一种木腐菌侵染橡胶树活立木的茎干引起,株发病率约为1%~2%,田间发生茎腐病的断干橡胶树植株,新抽枝条上的叶片失绿,无光泽,变黄后脱落,后期树冠稀疏,生长不良、枯枝,病树茎干木质部组织白腐,重病植株整株枯死。对该病害的病原菌进行致病性测定、形态学特征鉴定,并建立ITS、LSU和SSU多基因系统发育树。结合形态学鉴定和多基因系统发育树鉴定结果,海南橡胶树灵芝茎腐病的病原菌鉴定为南方灵芝[Ganoderma austral(Fr.)Pat.]。生物学特性测定结果表明,该菌的菌丝最适生长条件为:温度30℃,pH 6.0,黑暗条件,马铃薯葡萄糖琼脂(PDA)培养基培养。

A new stalk rot disease was found in rubber forests in Chengmai,Hainan Province.It was caused by a wood rot fungus of Ganoderma infecting the stems of live rubber trees.The incidence rate of the plant was about 1%-2%,which occured in the field.When rubber trees were infected by this stem rot disease,the leaves on the newly extracted shoots were chlorotic,dull,and fell off after yellowing.Later the crowns were sparse,poor growth,branches dead,and tissues of diseased stem xylem white rot.Some plants die when they were seriously ill.The pathogenicity and morphological characteristics were determinated,and the ITS,LSU and SSU multigene phylogenetic trees were established.Results showed that the pathogen causing stem rot of Hevea brasiliensis was Ganoderma austral(Fr.)Pat.Tests on biological characteristics showed that the optimum identified growth conditions for G.austral were 30℃,pH 6.0,continuous darkness,PDA.