【摘要】 油茶软腐病于五十年代末在我国一些油茶栽培地区陆续发现,但迄今病原菌尚未肯定。本文着重报道病原菌的鉴定和分类。为给鉴定病原菌提供资料起见,试验中分别进行了人工接种,结果实验室内的叶片和枝梢水槽溅水二项保湿措施却只产生与大田病株相同的病斑而极少在病斑表面形成"蘑菇"型分生孢子座,只有实验室外的三项处理,即使用病组织分离获得的培养物接种,也获得52.2—100%形成"蘑菇"型分生孢子座的病叶率。从而证实了油茶软腐病病斑及其表面上的"蘑菇"型构制是同一种菌所产生,并证实了"蘑菇"型构制是病原菌的子实体。再从大田叶斑表面形成(乃至人工诱发)的黑顶的和未黑顶的"蘑菇"型的分生孢子座的切片看出,黑顶的顶面全部为瓶梗和瓶梗孢子链所覆盖,而未黑顶的则展示出是由极紧密的分生孢子梗从其柄部顶端向边缘辐射生长组成。这就清楚表明,这种"蘑菇"型构制是病原菌的分生孢子座,从而为鉴定提供较为完整的资料。研究中也将本菌与两近似属Nalanthamala和Agyriella进行了比较,可是发现这两个属的任何一个也不能安置油茶软腐病病原菌。因而我们以油茶伞座孢Agaricodochtum camelliae Liu,Wei et Fan,sp.nov.为模式种而成立一新属——伞座孢属Agartcodochtum Liu,gen.更多还原

【Abstract】 A soft-rot disease of tea-oil trees was found in succession in some plantations in China in the late 1950’s, but so far the causal fungus has not been identified. This paper deals with the identification and classification, as well as the symptomatology, host-range, cultural characteristics, pathogenicity and formation of the’ agariclike’ structures (i.e. sporodo-chia) of the pathogenic fungus.The causal fungus was isolated from sporodochia or diseased tissues. No difference in cultural charaters of the isolates from both sources was observed. Inocula including :bits of mycelia from pure culture isolated from diseased tissues and single sporodochia on the leaves of the teaoil trees from the field, were artificially inoculated to the leaves of these plants in moist chamber, to leafy branches in water culture and to plants growing in diseasefree region. Results of these inoculations showed that all symptoms caused by these two different kinds of inocula were similar, also that similar leaf spots appeared on leaves either inoculated in the laboratory or inoculated in the open field. However, in the first treatment only a low percen- tage (10.3%) of leaves forming sporodochia on leaf-spots could be found. Higher percentages might be obtained by:(1) placing the inoculated branches in an open large glass chamber and sprayed with water at intervals to maintain a dry and moist condition alternately.(2) placing the leafy branches into a thick growth of grasses under the forestry which was free of tea-oil trees 24—48 hrs. after leaf-spots appeared on these branches inoculated in the laboratory.(3) inoculating the leaves of tea-oil trees in disease-free region directly.52.2—100% of leaves formed sporodochia on their leaf spots, even if bits of mycelia from cultures isolated from diseased tissues were used as inoculum. It proved that all leaf-spots, sporodochiaforming or non-sporodochia-forming, were caused by the same causal fungus. In the meantime, it was also proved that the ’agaric-like’ structures, i.e. sporodochia were fruit bodies of the fungus. Sections from both spore-forming (naturally developed or artificially induced) ’black’ and non-spore-forming ’white’ sporodochia were made. It was observed that the entire upper surface of the former was covered with phialides together with phialospores, and the latter was composed of densely compacted conidiophores growing radiantly from the apex of the stem of the ’agaric-like’ structures and it was clearly indicated that they were sporodochia of the pathogenic fungus.In attempts to identify the pathogen, the present authors have compared this fungus with the two allied genera, Nalanthamala and Agyriella. There was no evidence, however, that would warrant the placing of this fungus in either of these two genera. Therefore, we base on the causal organism of the soft-rot disease of tea-oil trees, Agaricodochium camelliae Liu, Wei et Fan sp. nov. as a type species to found a new genus, Agaricodochium Liu gen. nov.The type specimen is deposited in the Mycological Herbarium of the Institute of Microbiology, Academia Sinica, Beijing.更多还原