桉树紫斑病病原菌探讨

A PRELIMINARY STUDY ON PATHOGENIC FUNGI OF THE LEAF PURPLE SPOT BLOTCH OF EUCALYPTUS SPP.

桉树紫斑病的原病菌,据以往报道,我国仅有桉壳针孢(Seploriamortarlensis Penz.et Sacc.)一个种。本文作者基于滇中、滇西的赤桉和大叶桉紫斑病标本,根据病原菌之产孢方式为全壁茅生环痕式 hb-ann),孢子梗顶部具1～3个环痕,分生孢子浅褐色,表面多有小粒状突起显粗糙等特征,确认其并非桉壳针孢而是桉壳褐针孢(Phaeoseptoria eucalypti Hansf.)。该病原在我国属首次报道。文中讨论了上述两个种形态特点的主要差异。

According to the past reports,Septoria mortarlensis Penz.et Sacc.was the only species which cause the leaf purple spot blotch of Eucalyptus spp. in China.Examination of the fungus on the specimens which were collected by the author on Eucalyplus camaldulensis and E.robasta in middle and west- stern Yunnan shows that it differs from Septoria spp.in several respects.The conidium development is holoblastic-annellidic,the conidiophores are annellop- hores with 1-3 ridges.The conidia are not hyaline,but brownish.The wall of conidia is minutely roughened. The author offirms that it is Phaeoseptoria eucalypti Hansf.cmed.J. Walker.The species is new to China.The main differences between Phaeosep- toria eucalypti and Septoria mortarlensis are discussed.