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…     

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。     

金黄壳囊孢菌分生孢子器发育过程研究

本文探究了金黄壳囊孢菌Cytospora chrysosperma分生孢子器的发育过程。发育初期,多根菌丝频繁分隔及分支,菌丝细胞变短呈近球形,菌丝围绕其中心点不断接触缠绕,并逐渐扩展,即通过多丝合生的方式形成分生孢子器原基;随着分生孢子器原基的不断成熟与壮大,其内厚壁细胞紧密围绕成空腔,空腔多次发生后形成多个相对独立、且均与中心腔室联通的腔室结构;在腔室发育的过程中,腔室内壁细胞逐渐发育形成长短不一、具有分支结构的分生孢子梗,并在其顶端通过内壁芽生式、单生的方式产生成熟的腊肠形分生孢子,孢子脱落后聚集于空腔内;随着中心腔室的成熟,分生孢子器逐渐突出于植物表皮,遇到合适的环境时,分生孢子角挤破表皮形成孔口,释放出分生孢子。成熟的分生孢子器一般位于寄主植物的皮层部分。     

中国长蠕孢属的分类研究II. 四川省的两个新种

报道生于四川省枯树枝上的长蠕孢属两个新种,假喙长蠕孢Helminthosporiumspurirostrum和四川长蠕孢Helminthosporiumsichuanense。假喙长蠕孢的分生孢子可产生假喙,这是首次报道长蠕孢属的一个新的特征。四川长蠕孢与黄檀长蠕孢H.dalbergiae较相似,但是黄檀长蠕孢的分生孢子大(长58-125靘,宽12-14靘),分生孢子梗细(宽10-12靘)。研究标本保存在山东农业大学植物病理学标本室(HSAUP)。     

中国长蠕孢属的分类研究Ⅱ.四川省的两个新种

报道生于四川省枯树枝上的长蠕孢属两个新种,假喙长蠕孢Helminthosporium spurirostrum和四川长蠕孢Helminthosporium sichuanense。假喙长蠕孢的分生孢子可产生假喙,这是首次报道长蠕孢属的一个新的特征。四川长蠕孢与黄檀长蠕孢H.dalbergiae较相似,但是黄檀长蠕孢的分生孢子大(长58-125μm,宽12-14μm),分生孢子梗细(宽10-12μm)。研究标本保存在山东农业大学植物病理学标本室(HSAUP)。     

中国长蠕孢属的分类研究II. 四川省的两个新种

报道生于四川省枯树枝上的长蠕孢属两个新种,假喙长蠕孢Helminthosporiumspurirostrum和四川长蠕孢Helminthosporiumsichuanense。假喙长蠕孢的分生孢子可产生假喙,这是首次报道长蠕孢属的一个新的特征。四川长蠕孢与黄檀长蠕孢H.dalbergiae较相似,但是黄檀长蠕孢的分生孢子大(长58-125靘,宽12-14靘),分生孢子梗细(宽10-12靘)。研究标本保存在山东农业大学植物病理学标本室(HSAUP)。     

下垂虫草的重寄生现象及重寄生菌的鉴定

在安徽省岳西县鹞落坪自然保护区,发现了1种寄生于下垂虫草(Ophiocordyceps nutans)的重寄生菌。通过形态特征观察和ITS序列分子生物学分析,将其鉴定为枝多头霉(Polycephalomyces ramosus)。其孢梗束着生于下垂虫草子实体的可孕部,顶部膨大呈球形。本种具有产生单个卵形的A型分生孢子的顶侧生排列的A型瓶梗和能形成分生孢子链的B型瓶梗,并在培养基上的气生菌丝和孢梗束的柄部都观察到梭形、链生的B型分生孢子。GenBank中相关种的ITS序列与拉丁名可能有误。     

中国一新记录属--梨尾格孢属

梨尾格孢属 中国新记录属 菌丝体表生,无子座,刚毛和附属丝缺;分生孢子梗单生,具分枝,常呈拱形,有时集结成环,比普通菌丝略粗;产孢细胞单孔生,顶生,或间生,有限产孢,圆柱状、棍棒状或钩状,具孢痕疤,疤痕突出,疤痕中央常显产孢孔。分生孢子单生,干燥、顶生或侧生,宽椭圆形,卵圆形、球形、近球形或倒梨形,常具喙或附属丝,褐色,砖格状分隔,光滑或具有瘤突。 模式种： Piricauda paraguayensis (Speg.) R. T. Moore = P. uleana (Sacc.& Syd.) Bubák.     

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)。     

球束梗孢属一新种

描述了采自湖北省神农架的球束梗孢属一新种,神农架球束梗孢Gibellula shennongjiaensis,该菌分生孢子梗表面粗糙,瓶梗为棒状,5.4–10.8×1.1–2.2μm。分生孢子为圆柱形或纺锤形,透明,表面光滑,3.2–6.5×1.1–1.6μm。具糙梗孢式共无性型的产孢结构,其分生孢子梗由不规则的菌丝组成,产孢细胞不规则形状,分生孢子无色,光滑,线形,12.1–15.2×1.4–2.1μm。模式标本保存在贵州大学菌种保藏中心(GZAC-SNJ2012,主模式)。     

采用EF-1α序列及气生菌丝上的孢子形态特征对九州镰孢菌、拟枝孢镰孢菌和厚垣镰孢菌的鉴定

对九州镰孢菌Fusarium kyushuense、厚垣镰孢菌F. chlamydosporum 和拟枝孢镰孢菌F. sporotrichioides在气生菌丝上产生的孢子进行了比较。九州镰孢菌在气生菌丝上产生多隔孢子（即中型分生孢子）;厚垣镰孢菌在气生菌丝上产生的主要是0隔针叶状分生孢子;拟枝孢镰孢菌在气生菌丝上产生两种类型的分生孢子：芜菁形、单胞分生孢子以及椭圆形、0－1隔的分生孢子。多隔的气生孢子（中型分生孢子）在厚垣镰孢菌和拟枝孢镰孢菌这两个种中偶尔可以观察到,但是不应作为对这两个种进行鉴定的主要     

Variability in Indian Isolates of Arthrobotrys dactyloides Drechsler: A Nematode-Trapping Fungus

Five isolates of Arthrobotrys dactyloides (A, B, C, D, and E) were isolated from different locations of India. Their variability in relation to morphology, radial growth, and nematode capturing or trap-forming ability was observed. All of the five isolates produced two-celled slender conidia, whereas wider two- and three-celled conidia were produced by isolates A, C, D, and E only. The wider two- and three-celled conidia were not observed in cultures of isolate B. The isolate B produced macroconidia as well as microconidia. The microconidia were produced on separate conidiophores of smaller size. Macroconidia and microconidia were never produced on the same conidiophore, but the two types of conidiophores were produced on same or different hyphae. Similar to macroconidia, the microconidia also produced constricting rings of smaller size in presence of Meloidogyne graminicola. The constricting rings formed on microconidia did not capture second-stage juveniles of M. graminicola because of their smaller size. Among all the isolates, isolate B showed slow growth and higher nematode-capturing ability or trap-forming ability.     

Changes in lipid composition of Blumeria graminis f.sp. tritici conidia produced on wheat leaves treated with heptanoyl salicylic acid

Treatment of wheat leaves with heptanoyl salicylic acid (HS) and trehalose at concentrations of 0.1 and 15 g l(-1), prior to fungal inoculation, resulted in 40% and 60% protection, respectively, against powdery mildew. The total lipid composition of Blumeria graminis f.sp. tritici (Bgt) conidia, the causal agent of wheat powdery mildew, was compared when produced on wheat leaves, respectively, untreated and treated with the two elicitors, HS and trehalose. An obvious effect was observed on lipid composition (sterol and fatty acid (FA)) of Bgt conidia produced on wheat leaves treated with HS. A total of 16 FA (C12-C24 saturated and unsaturated) as well as unusual methoxylated Fatty Acids (mFA) (3-methoxydocosanoic and 3-methoxytetracosanoic acids) were detected in the conidia. Medium chain FA were predominant in HS treated conidia (64.65%) while long chain fatty acids constituted the major compounds in untreated conidia (62%). The long chain/medium chain FA ratio decreased from 1.8 in the conidia produced on untreated leaves to 0.5 in the conidia obtained from HS treated leaves. When comparing the sterol composition of Bgt conidia produced on leaves treated with HS versus conidia obtained from untreated ones, very important changes within the two major classes can be seen. In particular, 24-methylsterols, e.g., 24-methylenecholesterol and 24-methylcholesta-7,24-dien were reduced by about 82% whereas 24-ethylsterols, e.g., 24-ethylcholesterol and 24-ethylcholesta-5,22-dienol were increased by about 85%. The 24-methylsterols/24-ethylsterols ratio was reduced by ninefold in the conidia produced from HS treated leaves.     

Conidioma production of the white root rot fungus in axenic culture under near-ultraviolet light radiation

 Conidiomata of the white root rot fungus were produced in axenic culture under near-ultraviolet light radiation. Pieces of sterilized Japanese pear twigs were placed on 7-day-old oatmeal agar culture in plates. The plates were further incubated for 5 days and then illuminated by near-ultraviolet light. Synnemata developed on the twigs within 5 weeks in 19 of 20 isolates tested, and conidia were observed in 12 of the 19 isolates. The synnemata and conidia produced were morphologically identical to those of Dematophora necatrix. Received: October 29, 2001 / Accepted: March 11, 2002     

The roles of ascospores and conidia of Pyrenopeziza brassicae in light leaf spot epidemics on winter oilseed rape (Brassica napus) in the UK

Ascospores of Pyrenopeziza brassicae were produced in apothecia (cup‐shaped ascomata) on oilseed rape debris. The conidia, which were morphologically identical to the ascospores, were produced in acervular conidiomata was greater than for lesions caused by ascospores. In June 2000, on the ground under a crop with light on the surface of living oilseed rape tissues. Ascospores were more infective than conidia on oilseed rape leaves. The proportion of lesions caused by conidia located on leaf veins leaf spot, numbers of petioles with apothecia decreased with increasing distance into the crop from the edge of pathways. Air‐borne ascospores of P. brassicae were first collected above debris of oilseed rape affected with light leaf spot on 5 October 1998 and 18 September 1999,12 or 23 days, respectively, after the debris had been exposed outdoors. P. brassicae conidia were first observed on leaves of winter oilseed rape on 6 January 1999 and 15 February 2000, respectively, after plots had been inoculated with debris in November 1998 and October 1999. In 1991/92, numbers of ascospores above a naturally infected crop were small from January to April and increased in June and July. P. brassicae conidia were first observed in February and the percentage plants with leaves, stems or pods with light leaf spot increased greatly in May and June. In 1992/93, in a crop inoculated with debris, numbers of airborne ascospores were small from October to January and increased from April to June. P. brassicae conidia were first observed on leaves in late November and light leaf spot was seen on stems and pods in March and June 1993, respectively.     

Effect of Light, Temperature and Substrate during Spore Formation on the Germinability of Conidia of Colletotrichum falcatum

This paper presents results on the effect of light, temperature and substrate during spore formation on the germinability of conidia in Colletotrichum falcatum. Light seems to have no effect on the germination of conidia unless the cultures were exposed to a high intensity of light during sporulation, in which case the spores showed a reduced germination and an increased appressoria formation. Conidia produced at temperatures higher than the optimum showed better germination and less appressoria formation than the spores produced at the temperature optimum for the growth and sporulation of the fungus. A similar increase in germination was also observed in conidia obtained from inoculated sugarcane leaves as compared to those produced on culture media. The light type virulent isolates of C. falcatum showed greater sensitivity to all these treatments than the dark type weakly pathogenic isolates.     

Visible light during mycelial growth and conidiation of Metarhizium robertsii produces conidia with increased stress tolerance

Light conditions during mycelial growth are known to influence fungi in many ways. The effect of visible-light exposure during mycelial growth was investigated on conidial tolerance to UVB irradiation and wet heat of Metarhizium robertsii, an insect-pathogenic fungus. Two nutrient media and two light regimens were compared. Conidia were produced on (A) potato dextrose agar plus yeast extract medium (PDAY) (A1) under dark conditions or (A2) under continuous visible light (provided by two fluorescent lamps with intensity 5.4 W m(-2)). For comparison, the fungus was also produced on (B) minimal medium (MM) under continuous-dark incubation, which is known to produce conidia with increased tolerance to heat and UVB radiation. The UVB tolerances of conidia produced on PDAY under continuous visible light were twofold higher than conidia produced on PDAY medium under dark conditions, and this elevated UVB tolerance was similar to that of conidia produced on MM in the dark. The heat tolerance of conidia produced under continuous light was, however, similar to that of conidia produced on MM or PDAY in the dark. Conidial yield on PDAY medium was equivalent when the fungus was grown either under continuous-dark or under continuous-light conditions.     

Effect of relative humidity and origin of isolates of Neozygites tanajoae (Zygomycetes: Entomophthorales) on production of conidia from cassava green mite, Mononychellus tanajoa (Acari: Tetranychidae), cadavers

Neozygites tanajoae is a very specialized fungus pathogenic to the cassava green mite (CGM), Mononychellus tanajoa, an important cassava pest introduced to Africa from the Neotropics. Conidial discharge from cadavers of CGM that died from infections with 14 isolates of N. tanajoae collected from diverse climates of Brazil was quantified to help select potential candidate strains for introduction to Africa. Studies aimed to identify isolates with lower requirements for relative humidity for sporulation and isolates that discharged more conidia during short periods of moisture. At 96 ± 0.5% RH, production of conidia was variable and even isolates from the Brazilian semi-arid region, e.g., Petrolina and Itaberaba, produced few conidia. Significant differences in the numbers of conidia produced by diverse Brazilian isolates were observed after 6, 9 and 12 h at 100% RH. At 100% RH, production of primary conidia increased considerably from an average of 57 ± 4 conidia at 6 h to 509 ± 37 conidia at 12 h. The isolate sporulating least (BIN21) discharged only 45.7% of the number of conidia produced by isolate BIN1, one of the isolates producing the most spores. Results from this study demonstrate that differences in production of conidia among isolates should be considered when selecting Neozygites isolates for new biological control introductions.     

Impact of nutritional conditions on yields,germination rate and shelf-life of Plectosporium alismatis conidia and chlamydospores as potential candidates for the development of a mycoherbicide of weeds in rice crops

The effect of nutritional conditions on spore qualities was investigated in order to select which propagules, conidia or chlamydospores, would be most suitable for mycoherbicide development. Plectosporium alismatis was grown in a liquid basal medium supplemented with glucose and a mineral nitrogen source (sodium nitrate) or an organic nitrogen source (casamino acids). Conidial and chlamydospore yields, germination rate and shelf-life were compared. Two growth models were developed: on one hand, sodium nitrate added as the sole nitrogen source was partially utilised (8%), resulting in poor growth (1.77±0.02 mg mL^?1; 6±1.7×10⁵ conidia mL^?1). Under these conditions, P. alismatis produced dense, melanised-like aggregates that contained chlamydospores (12.4±0.7×10⁴ chlamydospores mL^?1). Germination rates of chlamydospores and conidia produced under these conditions was high (80%). Twenty percent of chlamydospores were able to germinate after 4 months storage at 25°C, while survival of conidia declined rapidly (<2%). When casamino acids were added to the liquid medium as the sole nitrogen source, P. alismatis produced sparser pellets resulting in high dry weights (5.37±0.09 mg mL^?1 and high conidia numbers (9.6±1.5×10⁶ conidia mL^?1), while no chlamydospore were observed. The germination rate of conidia produced in casamino acids was low (33±13%) after 8 h incubation and microcycle conidiation occurred. Five percent of these conidia germinated after 4 months storage. These data indicate that chlamydospores may be suitable for mycoherbicide development, provided further optimisation of yields is achieved.