从分子系统发育探讨内生拟盘多毛孢与病原拟盘多毛孢的关系

收集马尾松、罗汉松、竹柏、山茶、茶和茶梅等植物的内生和病原拟盘多毛孢菌株,进行形态鉴定,根据rDNA ITS序列分析建立的系统发育树探讨病原与内生拟盘多毛孢之间的相互关系.结果表明,同一个种拟盘多毛孢不论是内生还是病原均聚在系统发育树的同一个分支,如罗氏拟盘多毛孢(Pestalotiopsis lawsoniae)既是马尾松枝条的内生真菌,又是马尾松针叶的病原真菌;卡斯特尼拟盘多毛孢(Pestalotiopsis karstenii)是山茶枝条的内生真菌,在山茶叶片上也是病原真菌;石楠拟盘多毛孢(Pestalotiopsis photiniae)是山茶和茶梅枝务的内生真菌,在马尾松针叶上也是病原真菌;茶拟盘多毛孢(Pestalotiopsis theae)是茶的病原真菌,在金花茶枝叶和罗汉松枝上是内生真菌.说明某些拟盘多毛孢在不同(或相同)的植物或器官中可以表现为内生状态或病原状态,内生拟盘多毛孢在一定条件下可以转变为病原拟盘多毛孢.本研究结果还支持拟盘多毛孢种一般对寄主植物没有专化性的结论.

Molecular phylogenetic investigation on relationship of endophytic and pathogenic Pestalotiopsis species

Isolates of endophytic and pathogenic Pestalotiopsis from Pinus massoniana,Podocarpus macrophyllus,Podocarpus nagi,Camellia japonica,Camellia sinensis and Camellia sasanqua were collected and morphologically identified.The investigation on relationship between endophytic Pestalotiopsis and pathogenic Pestalotiopsis species based on molecular phylogenetic tree of rDNA ITS sequences was carried out.It was found that Pestalotiopsis isolates of the same species no matter it was pathogenic or endophytic were clustered in the same branch of phylogenetic tree,for example,P.lawsoniae was an endophytic fungus on twigs and a pathogen on leaves of P.massoniana;P.karstenii was an endophytic fungus on twigs and a pathogen on leaves of C.japonica;P.photiniae was an endophytic fungus on twigs of C.japonica and C.sasanqua and a pathogen on leaves of P.massoniana;and P.theae was a pathogen on leaves of C.sinensis and an endophytic fungus on twigs and leaves of C.nitidissima and twigs of P.macrophyllus.The result showes that some Pestalotiopsis species could be endophytic and pathogenic states on different species or parts of plant and an endophytic Pestalotiopsis could transformed into a pathogenic Pestalotiopsis under a certain condition.The result also supportes the previous conclusion that Pestalotiopsis species are not generally specific to host plants.