食线虫节丛孢及其相关属的分生孢子发育研究

采用小室培养法对食线虫丝孢菌节丛孢及其相关属的分生孢子发育类型进行了研究。报道了21个种的发育类型并描述了节丛孢属部分代表种的详细发育过程。结果表明,节丛孢属分生孢子的发类型为全壁芽生合轴式产孢,单顶孢属和隔指孢属的发育类型为全壁芽生式产孢。此发育学的研究结果不赞成小属分类观,支持了大属分类观,为这类群菌的分类和以此为基础的属征修定提供了参考依据。     

短柄链蠕孢分生孢子发育的研究

短柄链蠕孢(Dendryphion nanum)为暗色丝孢菌,其分生孢子棒状,5～20个隔膜,暗褐色,串生。试验通过玻片培养观察研究了该菌分生孢子的产生方式及发育类型。结果表明:该菌的分生孢子是由产孢细胞的顶端向外突起并生长膨大而形成,因而属于全壁芽生式产孢方式。     

球壳孢目真菌个体发育研究Ⅰ:壳二胞等四属

人工培养条件下,用光学显微镜和透射电子显微镜对球壳孢目（Sphaerosidales）的Ascochyta,Phyllosticta,Phomopsis,Septoria四属进行个体发育研究,明确了其产孢方式：Ascochyta和Phyllosticta为内壁芽生瓶梗式;Phomopsis为全壁芽生瓶梗式;Septoria为全壁芽生合轴式,这一结果为属级分类提供了可靠的依据。产孢方式是属内共同具有的稳定特征,分生孢子的形成方式类型、产孢细胞及分生孢子的形态是划分属的首要标准。以寄主植物属为基础确定的同属大多数种在个体发育上无明显差别,分生孢子的形态及大小是分种的一个重要依据。     

球壳孢目真菌个体发育研究I：壳二胞等四属

人工培养条件下,用光学显微镜和透射电子显微镜对球壳孢目(Splnaerosidales)的Ascochyta, Phyllosticta, Phomopsis, Septoria四属进行个体发育研究,明确了其产孢方式：Ascochyta 和Phyllosticta为内壁芽生瓶梗式;Phomopsis 为全壁芽生瓶梗式;Septoria为全壁芽生合轴式,这一结果为属级分类提供了可靠的依据。产孢方式是属内共同具有的稳定特征,分生孢子的形成方式类型、产孢细胞及分生孢子的形态是划分属的首要标准。以寄主植物属为基础确定的同属大多数种在个体发育上无明显差别,分生孢子的形态及大小是分种的一个重要依据。     

梨形短梗蠕孢的分生孢子发育研究

采用玻片培养法对梨形短梗蠕孢(Trichocladium achrasporum)的分生孢子发育类型进行了研究。观察结果表明,梨形短梗蠕孢分生孢子既可以在菌丝顶端形成(顶生式),也可以在菌丝中间形成(间生式),其发育方式是全壁芽生式产孢。     

引起青稞和燕麦鞘腐病的无性型菌物新属种——禾生指葡孢霉

引起甘肃及邻省青稞和燕麦鞘腐病的病原菌为无性型真菌anamorphic fungi中一未描述的丛梗丝孢菌moniliaceous hyphomycete。该菌分生孢子梗无色,散生,直立或匍匐;交互、叉状、聚伞状或帚状分枝。产孢细胞簇生于分生孢子梗末级分枝顶端成指状或掌状,顶部常具齿状着孢点,全壁芽生式产孢。分生孢子无色、单胞,罕有一个隔膜,近球形、卵圆形、倒梨形、纺锤形、葫芦形或不规则形,表面具网状脊或疣突,在孢梗顶端常聚集成葡萄状。分生孢子群体白色,随培养物老化,渐变为淡黄色。本菌与葡萄孢属Botrytis及其他Botrytis-like形态相似属明显不同,故建立指葡孢霉属Dactylobotrys(新属);模式种为禾生指葡孢霉Dactylobotrys graminicola(新种)。模式标本保存在中国科学院菌物标本馆(HMAS 245110,主模式)和甘肃省农业科学院植物保护研究所植物病害标本室(GAPP 1131,等模式)。     

中国一新记录属--斯氏格孢属

斯氏格孢属 中国新记录属Spegazzinia Saccardo, Michelia 2：37 , 1880. 菌落松散,正圆形或平展,暗褐色至黑色;菌丝体表生;子座无,刚毛和附属丝缺;菌丝多分枝,常相互融合集结成网状;分生孢子梗常从近球形、安瓶形、盘形或瓮形的孢梗母细胞上生出,不分枝,直立或弯曲,窄细,近无色至褐色,光滑或具有瘤突。分生孢子梗常分为长、短两型,分别产生a,b两种类型的分生孢子：a分生孢子生在长的分生孢子梗上,b分生孢子生在短的分生孢子梗上;产孢细胞于顶端全壁芽生式产孢,单芽生,有限生长,窄细,圆柱状;分生孢子单生;a分生孢…     

两种捕食线虫丝孢菌形态多样性研究

多头节丛孢和附胞隔指孢是两种极不常见的捕食线虫丝孢菌,Ａ．ｐｏｌｙｃｅｐｈａｌａ为国内新纪录种。通过对这两种菌的形态观察发现：Ａ．ｐｏｌｙｃｅｐｈａｌａ的大、小分生孢子均可萌发,后代同母体,小分生孢子一般为单端萌发,大分子生孢子为两端萌发,并且小分子孢子可以继续发育形成在分生孢子。这两种菌均形成类似厚坦孢子的结构。     

圆盘菌科真菌及其无性型的研究*

圆盘菌科Orbiliaceae真菌是小型盘菌,由于不清楚其经济价值,人们一直认为它是个不重要的类群,很少有人进行过研究(Alexopoulos et al.,1996)。Pfister(1994)报道粪生圆盘菌Orbilia fimicola Jeng & Krug是捕食线虫丝孢菌节丛孢属Arthrobotrys的有性型,从而引起真菌学家们的关注。捕食线虫丝孢菌以其巧妙的菌丝变态器官捕食线虫,长期以来一直吸引着众多真菌学家的注意,进行了广泛的研究。在分类学方面,捕食线虫丝孢菌分类的主要依据靠分生孢子的形态,没有真正体现出其自然发育的亲缘关系(Hagedorn & Scholler, 1999)。圆盘菌属Orbilia F…     

紫杉醇产生菌HQD33的鉴定

通过对紫杉醇产生菌HQD33的群体形态和菌丝、分生孢子梗、产孢细胞、分生孢子等个体形态的研究,确定了HQD33的分类地位,为树状多节孢.     

Bambusicolous fungi in Japan (7): a new coelomycetous genus, <Emphasis Type="Italic">Versicolorisporium</Emphasis>

A new genus, Versicolorisporium, is established for the coelomycetous fungus collected in Japan on dead culms of the bamboos Pleioblastus chino and Sasamorpha borealis. The type species of the genus, V. triseptatum, is characterized by the production of holoblastic, 3-septate, obovoid, versicolored conidia. Versicolorisporium is similar to Toxosporiella, Neohendersonia, Toxosporiopsis, and Scolicosporium in having versicolored conidia, but differs from these genera by the uniloculate pycnidial conidiomata with a periphysate ostiole, lacking paraphyses, and the conidia without black-banded septa. A BLAST search using LSU nrDNA sequence indicates that the new genus is a member of Pleosporales, Dothideomycetes.     

Fusarium kyushuense sp. nov. from Japan

Four trichothecene-producing strains originally isolated from diseased wheat and a vinyl plate in Kyushu and Shikoku, Japan are described and illustrated as a new species,Fusarium kyushuense. This species does not produce chalamydospores, which is the key morphological character which distinguishes it fromF. sporotrichioides with which it has been mistaken.Fusarium kyushuense is also differentiated from another morphologically similar species,F. arthrosporioides, by absence of sclerotia and by differences in conidiogenesis of obovate, conidia. InF. arthrosporioides conidia are partly holoblastic from the aerial conidiophores and mostly phialidic from the sporodochial conidiophores, while inF. kyushuense conidia are mostly holoblastic and only produced from aerial conidiophores.     

Digitomyces, a new genus of hyphomycetes with cheiroid conidia

The new anamorphic genus Digitomyces, based on Dictyosporium verrucosum, is proposed. It is characterized by micronematous or semimacronematous conidiophores, integrated or discrete, holoblastic, determinate conidiogenous cells, and olivaceous to pale brown, verrucose, cheiroid conidia, with a truncate basal cell and (2-)3 arms. The new taxon is compared with morphologically similar anamorph genera.     

Seimatoantlerium tepuiense gen. nov., a unique epiphytic fungus producing taxol from the Venezuelan Guyana.

Seimatoantlerium gen. nov., type species, S. tepuiense sp. nov. is proposed for an acervular fungus producing 4-septate, holoblastic conidia with 6-8 unbranched, apical appendages that dehisce as an appendage apparatus and also commonly possessing one or two exogenous basal appendages as well as a pedicel. It is compared with Seimatosporium, Seimatosporiopsis, and other genera. It is epiphytic on Maguireothamnus speciosus, a rubiaceous plant endemic to the tepuis of southeastern Venezuela. It produces the anti-oomycetous anticancer compound, taxol, as shown by immunological and spectroscopic methods. Taxol production is discussed relative to the ability of this fungus to exist in an extremely moist ecosystem, as well as to its relationship to other plant associated fungi.     

PCR-RFLP is used to investigate relations among species in the entomopathogenic genera Eryniopsis and Entomophaga

The shape and nucleation of primary conidia are important characters in the classification of the Entomophthoraceae (Zygomycetes). The five species in the genus Eryniopsis vary in the shapes of primary conidia, although within most genera in the order Entomophthorales species have the same shapes of primary conidia. Using PCR-RFLP, we investigated two species in Eryniopsis, Ery. caroliniana with oblong-ovoid primary conidia and Ery. ptychopterae with pear-shaped primary conidia, with five species of Entomophaga, all having pear-shaped conidia. Molecular results merged with morphological data indicate that Ery. ptychopterae belongs in the genus Entomophaga while Ery. caroliniana clearly differs from Entomophaga. Ery. ptychopterae and Ery. transitans are transferred to the genus Entomophaga. Our results support the idea that morphology of primary conidia is of major importance in defining entomophthoralean genera. These results also show that such studies can be conducted with species that have not been isolated, if fungal-filled cadavers can be obtained.     

Liberomyces gen. nov. with two new species of endophytic coelomycetes from broadleaf trees

During a study of endophytic and saprotrophic fungi in the sapwood and phloem of broadleaf trees (Salix alba, Quercus robur, Ulmus laevis, Alnus glutinosa, Betula pendula) fungi belonging to an anamorphic coelomycetous genus not attributable to a described taxon were detected and isolated in pure culture. The new genus, Liberomyces, with two species, L. saliciphilus and L. macrosporus, is described. Both species have subglobose conidiomata containing holoblastic sympodial conidiogenous cells. The conidiomata dehisce irregularly or by ostiole and secrete a slimy suspension of conidia. The conidia are hyaline, narrowly allantoid with a typically curved distal end. In L. macrosporus simultaneous production of synanamorph with thin filamentous conidia was observed occasionally. The genus has no known teleomorph. Related sequences in the public databases belong to endophytes of angiosperms. Phylogenetic analysis revealed a position close to the Xylariales (Sordariomycetes), but family and order affiliation remained unclear.     

The predatory capability of three nematophagous fungi in the control of Haemonchus contortus infective larvae in ovine faeces

The effect of oral administration of three different nematode-trapping fungi, in aqueous suspension containing either Dactylaria sp. or Arthrobotrys oligospora conidia or Duddingtonia flagrans chlamydospores, on the number of Haemonchus contortus infective larvae in sheep faeces, was evaluated. The three selected species of fungi produce three-dimensional adhesive nets in the presence of nematodes. Sixteen Creole sheep were divided into four groups of four animals each. Groups 1 and 2 were orally drenched with a suspension containing 2x10(7) conidia of either A. oligospora or Dactylaria sp. Group 3, received a similar treatment, with D. flagrans chlamydospores, instead of conidia, being administered, at the same dose. Group 4 acted as control, without any fungi. Faecal samples were collected directly from the rectum of each sheep and faecal cultures were prepared and incubated at 15 and 21 days. Larvae were recovered from faecal cultures and counted. The highest reduction of the nematode population occurred in the D. flagrans group, reaching reductions of 96.3% and 91.4% in individual samplings in plates incubated for 15 and 21 days, respectively. Arthrobotrys oligospora showed moderate reductions in the faecal larval population, ranging between 25-64% at 15 days incubation. In general, Dactylaria sp., was less efficient in its trapping ability. Despite the inconsistent results with Dactylaria sp., reduction percentages of 73.4% and 80.7% were recorded in individual samplings during the first and second days, in plates incubated for 15 days. Duddingtonia flagrans, was shown to be a potential biological control agent of H. contortus infective larvae.     

The fine structure of conidial development in the genus Torula. I. T. herbarum (Pers.) Link ex S. F. Gray and T. herbarum f. quaternella Sacc.

Conidiogenesis in Torula herbarum and T. herbarum f. quaternella was observed by scanning and transmission electron microscopy. Conidia of the former were shown to be made up of three equally sized cells capped by a distinctive, and easily recognizable, conidiogenous cell. Conidiogenous cells also arose terminally on erect hyphae and on prostrate hyphae. The single-layered conidial cell walls were differentiated into an inner hyaline zone and an outer electron-dense zone formed by the deposition of melanin. Conidiogenous cells lacked melanin at the apex and, before conidiation, the lateral walls were strengthened by a further deposition of melanin. The apex bulged outwards and was modified into a new multicelled conidium bearing another apical conidiogenous cell. Continued development of new conidia resulted in an acropetal chain which became disarticulated after cytolysis within the conidiogenous cell. The relative distinctions between holoblastic and enteroblastic development are discussed and it is concluded that the conidia should be referred to as blastoconidia.     

食线虫真菌28S rDNA PCR扩增片段的RFLPs分析*

本文对16个食线虫真菌(节丛孢属、隔指孢属和单顶孢属)菌株和3个其他相关丝孢菌(顶辐孢属和单端孢属)菌株的28S rDNA 片段进行了扩增, 并用限制性内切酶Sau3A I, Msp I, Rsa I and Hae III对PCR产物进行了消化。采用UPGMA法对 PCR 产物的限制性图谱特征进行了聚类分析。结果表明,捕食性真菌的聚类群与捕食器官类型相对应,顶辐孢属和单端孢属与捕食性真菌的遗传距离较远。该结果与rDNA 的ITS区间、5.8S和18S的序列分析结果一致。