霜霉属一新种

本文报道了采自我国新疆天山的唇形科（Ｌａｂｉａｔａｅ）青蓝（ＤｒａｃｏｃｅｐｈａｌｕｍｒｕｙｓｃｈｉａｎｕｍＬ．）上的霜霉菌新种－青蓝霜霉（ＰｅｒｏｎｏｓｐｏｒａｄｒａｃｏｃｅｐｈａｉｌＣ．Ｊ．ＬｉｅＺ．Ｙ．Ｚｈａｏｓｐ．ｎｏｖ．）对该种的形态做了拉丁文和汉文描述,并附有特征图,模式标本保存于新疆农业大学真菌株本室。     

霜霉属二新种

本文报道霜霉属（Ｐｅｒｏｎｏｓｐｏｒａ）新种二个：即寄生在石竹科植物异叶假繁缕（Ｐｓｅｕｄｏ ｓｔｅｌｌａｒｉａ ｈｅｔｅｒｏｐｈｙｌｌａ（Ｍｉｑ．）Ｐａｘ．）上的假繁缕霜霉（Ｐ．ｐｓｅｕｄｏｓｔｅｌｌａｒｉａｅ Ｇ．Ｙ．Ｙｉｎ ｅｔ Ｚ．Ｓ．Ｙａｎｇ）和寄生在荨麻科植物薮Ｎｉｎｇ麻（Ｂｏｅｈｍｅｒｉａ ｊａｐｏｎｉｃａ Ｍｉｑ．）上的Ｎｉｎｇ麻霜霉（Ｐ．ｂｏｅｈｍｅｒｉａｅ Ｇ．Ｙ．Ｙｉｎ ｅｔ     

轴霜霉一新种—地榆轴霜霉

本文报道了采自我国阿勒泰山寄生于蔷薇科植物地榆上的轴霜霉新种－地榆轴霜霉。轴霜霉寄生于蔷薇科植物上是首次报道。对该种的形态作了拉丁文和汉文描述并附有特征图。     

广西云南玉米霜霉病病原菌订正

在我国文献中广西云南玉米霜霉病菌名称为Ｐｅｒｏｎｏｓｃｌｅｒｏｓｐｏｒａ ｍａｙｄｉｓ（Ｒａｃｉｂ．）Ｃ．Ｇ．Ｓｈａｗ。但是我们观测病菌孢子囊为长椭球形;在１３℃－２８℃产孢温度范围内,随温度升高孢子囊长度增加而宽度基本不变,表明它不是Ｐ．ｍａｙｄｉｓ,而是Ｐ．ｓａｃｃｈａｒｉ（Ｔ．Ｍｉｙａｋｅ）Ｓｈｉｒａｉ ＆ Ｋ．Ｈａｒａ,或Ｐ．ｐｈｉｌｉｐｐｉｎｅｎｓｉｓ（Ｗｅｓｔｏｎ）Ｃ．Ｇ．Ｓｈａｗ。以     

霜霉属一新种

本文报道寄生在卷茎蓼Polygonum convolvulus L.植物上的一种霉霜,命名为中国霜霉Peronospora sinensis Tang,并作了描述和比较。     

轴霜霉一新种——地榆轴霜霉

本文报道了采自我国新疆阿勒泰山寄生于蔷薇科(Rosaceae)植物地榆(Sanguisorba officinalis L.)上的轴霜霉新种——地榆轴霜霉(Plasmopara Sanguisorbae C.J.Li et al.sp.nov.)。轴霜霉寄生于蔷薇科植物上是首次报道。对该种的形态作了拉丁文和汉文描述,并附有特征图。     

中国盘霜霉属在菊科植物上的分类单元

本文讨论了菊科植物上盘霜霉属Bremia的分类问题。根据专性寄生菌种的划分,在以形态特征为基础的同时,结合考虑寄生专化性或寄主范围的观点,我们提出菊科植物上Bremia的种的寄主限制在菊科“族”的范围内。对中国的菊科植物上Bremia属的已知种及变种列出了检索表,还报告了一个新种及一新组合,它们是兔苣盘霜霉(B.lagoseridis sp.nov.),寄生于兔苣(Lagoseris sanctae),和蓟盘霜霉(B.cirsii comb.nov.),寄生于蓟属(Cirsium spp.),标本保存于四川农业大学真菌实验室及中国科学院微生物所标本室。     

荔枝霜疫霉的研究

对华南的荔枝霜疫霉(Peronophythora litchii Chen ex Ko et al)的形态和营养特性进行了研究,并和新模式种进行了比较。发现此菌孢囊梗的生长是一种有限-无限生长类型,或称之为多级有限生长。即孢囊梗上的小分枝大多数是有限生长的,在其顶端同时形成孢子囊。但有时在同一孢囊梗上有的小分枝会继续生长,形成二级、三级甚至四级孢囊梗。在营养要求上与疫霉无大差别,能在天然和合成培养基上旺盛生长,需要硫胺素,ca~(++)和有机二元酸,能利用NH_4~+ 或No_3~-为其氮源,并能利用淀粉为其碳源,菌体匀浆中测出淀粉酶活性。根据孢囊梗的独特生长方式,我们认为完全有理由承认这菌是一个新属,并可成为新科,霜疫霉科。本文中已将霜疫霉科作了修改描述。孢囊梗已被修改为:孢囊梗多级有限生长。无疑这菌是腐霉科和霜霉科的中间类型。在营养类型与有性器官上和疫霉相近,而其孢子囊的形成和霜霉相似。但其孢囊梗的多级有限生长方式则和这两科都不相同。     

中国霜霉的几个新种

本文描述了霜霉属(Peronospora)两个新种。即:寄生于唇形科植物香薷(Elsholtziapatrnia Garcke)上的香薷霜霉(Peronospora elsholtziae sp.nov.)和寄生于大花益母草(Leonurusmacranthus Maxim.)上的大花益母草霜霉(Peronospora leonuri sp.nov);单轴霉属(Plasmopara)一个新种,寄生于车前草科植物车前草(Plantago major L.)上的车前草单轴霉(Plasmoparaplantaginicola sp.nov.,);盘梗霉属(Bremia)一个新种,寄生于石竹科植物莫石竹(Moehringialateriflora L.)上的莫石竹盘梗霉(Bremia moehringiae sp.nov.).这四个新种均有拉丁文和中文描述。还分别讨论了新种与同科近似种之间的区别。     

假霜霉一新种

本文报道寄生在香薷上的一种新的假霜霉,命名为香薷假霜霉(Pseudoperonospora elsh-oltniae Taog sp. Nov.),并作了描述。     

霜霉属二新种

本文报道霜霉属(Peronospora)新种二个:即寄生在石竹科植物异叶假繁缕(Pseudo stellaria heterophylla(Miq.)Pax.)上的假繁缕霜霉(P.pseudostellariae G. Y. Yin et Z.S.Yang)和寄生在荨麻科植物藪苧麻(Boehmeria japonica Miq.)上的苧麻霜霉(P.boehmeriae G.Y.Yin et Z.S.Yang)。文中有拉丁文及中文描述。标本保存于南京农业大学真菌标本室和中国科学院微生物所真菌标本室。     

霜霉一新种——薄荷霜霉

本文报道寄生在薄荷(Mentha aruensis L.)叶片上的一种新的霜霉,命名薄荷霜霉(Peronospora menthae X.Y.Cheng et H.C.Bai)对新种进行了汉文和拉丁文描述。     

霜霉属菌一新种——微孔草霜霉

本文报道寄生于甘青微孔草(Microula pseudotrichocarpa W.T.Wang)和疏花微孔草[M.diffusa(Maxim.)Johnst.]上的霜霉属一新种——微孔草霜霉(Peronospora microulaeMeng et G.Y.Yin)。以汉文和拉丁文描述此新种的形态性状,并。附图     

中国霜霉一新种*

本文描述了霜霉属(Peronospora)一个新种,寄生于唇形科植物水棘针(Amethysteacaerulea L·)上的水棘针霜霉(Peronospora amethysteae Y.Li et Bai sp.nov.),有拉丁文和中文描述,并讨论了新种与同科植物上的相近种之间的区别。     

中国霜霉一新种

本文描述了霜霉属(Peronospora)一个新种,寄生于唇形科植物水棘针(Amethysteacaerulea L·)上的水棘针霜霉(Peronospora amethysteae Y.Li et Bai sp.nov.),有拉丁文和中文描述,并讨论了新种与同科植物上的相近种之间的区别。     

乌头霜霉卵孢子的发现

本文第一作者于1979年发表乌头霜霉 Peronospora aconiti Yu新种时缺乏对卵孢子的描述,现在四川雅安的乌头 Aconitum cramichaeli Dexb.上发现了该菌的卵孢子,特予补充描述:藏卵器亚球形或卵形,平滑,直径25.8—51.6(平均39.42±4.47)μm;卵孢子球形,浅黄褐色,平滑,单生,不充满藏卵器,直径22.4—37.8(平均28.76±2.96)μm;卵孢子壁厚,其厚度为 2.84—5.04(平均3.77±0.61)μm。     

In vitro spore germination and infection of cultivars of Rubus and Rosa by downy mildews from both hosts

The cardinal temperatures for in vitro germination of conidia of imported and indigenous isolates of downy mildew from hosts in the genera Rubus and Rosa were similar. A high percentage of conidia germinated above 2°C and germination remained between 80% and 90% up to 15°C or 20°C, depending on the isolate. The highest incidence of disease on leaf disks of Tummelberry (blackberry × red raspberry) inoculated with an isolate of Peronospora rubi occurred at c. 15°C, with infection over a range from 2°C to 28°C. Tests on leaf disks in vitro, and leaflets of primocane and lateral shoots in plastic tunnels, with three hybrid berry (blackberry x red raspberry), six blackberry and nine red raspberry cultivars showed the hybrid berries to be most susceptible. In a plastic tunnel infected drupelets of red raspberry fruits developed more slowly and failed to ripen evenly compared with uninfected drupelets. Similar malformation of infected fruits occurred in a plantation of Tummelberry. An isolate of P. rubi attacked severely both Tummelberry and rose cv. Can Can. Fluorescence microscopy after staining with aniline blue showed that leaf disks of Tummelberry were extensively colonised by intercellular mycelium of P. sparsa isolated from rose, even though sporulation was sparse or absent. This supports the view that P. rubi and P. sparsa may be conspecific. Oospores of P. rubi were found routinely within leaf disks of Rubus cultivars inoculated in vitro and once in naturally infected leaflets of Tummelberry.     

Light and Electron Microscopy of the Compatible Interaction Between Arabidopsis and the Downy Mildew Pathogen Peronospora parasitica

In this study, we focused on compatible interactions between Peronospora parasitica isolate Emoy‐2 and wild‐type (Oy‐0) and mutant (Ws‐eds1) Arabidopsis thaliana accessions by using light and transmission electron microscopy (TEM). Light microscopy of compatible interactions revealed that conidia germinated and penetrated through the anticlinal cell walls of two epidermal cells. Rapid spreading of the hyphal growth with formation of numerous haustoria within the mesophyll cells was subsequently followed by profuse sporulation in the absence of host cell necrosis on both wild‐type and mutant accessions. TEM observations revealed that coenocytic intercellular hyphae ramified and spread intercellularly throughout the host tissue forming several haustoria in host mesophyll cells. Intracellular haustoria were lobed with the diameter of 6–7 μm. Each haustorium was connected to intercellular hyphae in the absence of apparent haustorial neck. The cytoplasm of the haustorium included the organelles characteristic of the pathogen. Callose‐like deposits were frequently observed at sites of penetration around the proximal region of the haustorial neck. Apart from a few callose ensheatments, no obvious response was observed in host cells following formation of haustoria. Most of mesophyll cells contained normal haustoria and the host cytoplasm displayed a high degree of structural integrity. Absence of host cell wall alteration and cell death in penetrated host cell of both accessions suggest that the pathogen exerts considerable control over basic cellular processes and in this respect, response to this biotroph oomycete differs considerably from responses to other pathogens such as necrotrophs.     

Occurrence of Peronospora sparsa (P. rubi) on cultivated and wild Rubus species in Finland and Sweden

An outbreak of a dryberry disease caused by Peronospora sparsa (syn. P. rubi) occurred in plantations of arctic bramble (Rubus arcticus subsp. arcticus) in Finland in the middle of 1990s. The disease persists and is most severe in cool and rainy summers. The disease has not been encountered in northern Sweden where cultivars (R. arcticus nothosubsp. stellarcticus) different from those in Finland are used. The occurrence of P. sparsa in wild Rubus spp. is virtually unknown in both areas and it is not known whether they constitute a potential infection source. Therefore, the aim of this study was to investigate the occurrence of P. sparsa on wild Rubus spp. growing in the vicinity of cultivations of arctic bramble. Symptomatic plants were sampled in 1997–1999. P. sparsa was detected using a light microscope, preceded by incubation of the sample in vitro if necessary, and by a polymerase chain reaction (PCR) based method. Plants of cultivated R. arcticus subsp. arcticus were commonly infected by P. sparsa in Finland. P. sparsa was also found on the cultivated R. arcticus nothosubsp. stellarcticus in Finland and Sweden. However, the infected plants of the cultivars of nothosubsp. stellarcticus seemed to be much less damaged than the cultivars of subsp. arcticus. Plants infected with P. sparsa were found in the populations of wild R. arcticus subsp. arcticus in both countries, and in cloudberry (R. chamaemorus) in natural habitats in Finland. In addition, P. sparsa was detected on specimens of R. arcticus subsp. arcticus (collected in 1966–1985) and R. chamaemorus (collected in 1899–1981) in Finnish herbaria. The samples of R. idaeus and R. saxatilis collected from the field in this study or investigated in the herbaria were not infected with P. sparsa. These data show that P. sparsa has not recently invaded Finland but has become an economically significant pathogen during the rapid expansion of cultivation of the apparently sensitive clones of arctic bramble.