诱导茄链格孢菌分生孢子形成的新技术

本文报道诱导茄链格孢菌(Alternaria solani)分生孢子形成的一种新技术。生长在马铃薯-葡萄糖-琼脂(PDA)上两天的茄链格孢菌琼脂块移接到玉米培养基上,置于日光灯下照射,诱发分生孢子梗生长。然后,再放在18℃下黑暗培养。12小时后,在菌丝块表面有大量的分生孢子形成。成熟的茄链格孢菌分生孢子用蒸馏水洗脱。     

紫杉醇产生菌HU1353的鉴定

通过对紫杉醇产生菌HU1 35 3群体形态的观察 ,以及个体形态包括菌丝、分生孢子梗、分生孢子、产孢细胞、是否具喙等特征的研究 ,确定了HU1 35 3的分类地位 ,为链格孢属一新种 ,命名为红豆杉链格孢。     

中国南方地区暗色丝孢真菌两个新种（英文）

霸王岭爱氏霉和版纳葚孢是采自我国南方地区的暗色丝孢菌的2个新种。霸王岭爱氏霉的主要特征是分生孢子梗分化明显,单生,产孢细胞单芽生并产生17–24个假隔膜,115–145×15.5–20μm,倒棍棒形的分生孢子。版纳葚孢的主要特征是分生孢子梗粗大,单生,产孢细胞单芽生并产生11–25个真隔膜,215–430×12–16μm,倒棍棒形分生孢子。     

层束梗孢属一新种

本文报道采自贵州的中国新记录属层束梗孢属Hymenostilbe一新种刺孢层束梗孢（Hymenostilbespiculatasp．nov．Huan,FanetLi）。该种寄生于蜘蛛,产孢细胞子实层状复被于孢梗束上,无瘤,多点芽菌产孢。分生孢子单生,光滑或具细刺,56～6．6×1．3～2．7μm。     

孤孢属两新种

在对新疆及海南岛的捕食线虫真菌的调查中发现2个真菌与已报道的孤孢属的真菌不同,确定为新种——长梗孤孢菌(Monacrosporium longiphorum Liu et Lu sp. nov.)和小舟形孤孢菌(Monacrosporium microscaphoides Liu et Lu sp. nov.)。长梗孤孢菌主要特征为分生孢子梗较长,448-660 μm,分生孢子3-4个分隔,39-65(54) × 13-22(18) μm。小舟形孤孢菌主要特征为孢子较小,0-3个分隔,以2个分隔为主,23-39(29) × 8-15.5(12)μm。在老的培养物中可见球形串生的厚垣孢子。     

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…     

桔黄赛多孢，一种潜在的致病有丝分裂产孢真菌

【目的】调查发现我国土壤中稀有且重要的真菌资源。【方法】采用经典形态学及分子系统学方法对获得的菌株进行鉴定。【结果】从一养殖场含有猪粪的土样中分离获得一赛多孢EM12901菌株。其主要鉴别特征是:在查氏培养基上,绒状,灰白色至淡棕色。分生孢子梗单生或分支;单生的分生孢子梗常退化为产孢细胞。产孢细胞顶生或侧生,透明至半透明,薄壁,柱状或轻微膨大的烧瓶状,(3.5-45.0)μm×(1.5-3.0)μm;分生孢子顶生或侧生,单生,透明至半透明,光滑,椭圆形、倒卵圆形或近柱状,(4.3-14.0)μm×(2.5-5.5)μm。【结论】基于形态学及分子系统学方法相结合鉴定,赛多孢EM12901菌株为我国一新记录种,桔黄赛多孢Scedosporium aurantiacum Gilgado,Cano,GenéGuarro。     

齿梗孢属二新种

报道分离自土壤中的齿梗孢属 Scolecobasidium 二新种:椭圆齿梗孢 Scolecobasidium ellipticum 和小孢齿梗孢 Scolecobasidium microsporum。椭圆齿梗孢与亚马逊齿梗孢 S. amazonense、粗腐植齿梗孢 S. crassihumicola 和倒卵齿梗孢 S. obovatum 形态近似,区别在于 S. amazonense 的分生孢子倒卵形,常在分生孢子基部形成一横隔膜,同样 S. crassihumicola 的分生孢子也仅具一横隔膜;S. obovatum 的分生孢子(10-25×4-6μm)明显地较新种的大,且表面光滑,因此容易区分。小孢齿梗孢与嗜粪齿梗孢 S. coprophilum、腐植齿梗孢 S. humicola 和小疣齿梗孢 S. verruculosum 分生孢子形态有些相似,但新种的分生孢子明显小于 S. coprophilum(6-12.5×2.8-4.2μm)和 S. humicola(7-13×2.8-4μm, Matsushima,1971)的,分生孢子梗也明显较后两者的短;此外,新种的分生孢子密生刺突,而 S. verruculosum 分生孢子表面遍生小疣,使它们陪此易于区分。二新种的模式标本(干制培养物)保存在山东农业大学植物病理学标本室(HSAUP)。     

中国一新记录属——多节孢属*

1993年从黑龙江穆棱的东北红豆杉Taxus cuspidata的树枝上分离到两株内生真菌,鉴定为多节孢属的树状多节孢Nodulisporium sylviforme, 属我国的新记录属,新记录种。该菌为紫杉醇产生菌（周东坡和平文祥,2001）多节孢属 中国新记录属Nodulisporium Press, Linnaea, 24:120～121, 1851; Ellis, Dematiaceous Hyphomycetes. p. 232, 1985. 菌落扩散型,灰色,褐色,橄榄色或黑褐色,常呈茸毛状。菌丝体部分内生,部分表生。子座无。无刚毛和附着孢。分生孢子梗与菌丝有区别,单生或束生,单根的分生孢子梗不分支或在近顶部多分支,弯曲…     

中国云南色串孢科的新种苍山长喙孢和新记录露

本研究对中国滇西北地区淡水木腐真菌进行了调查,在云南省的苍山、怒江和澜沧江采集到3个菌株。根据形态学特征和多基因系统发育分析（ITS、LSU、SSU、TEF1-α和RPB2）描述了新种——苍山长喙孢Rostriconidium cangshanense。苍山长喙孢的特征是菌体形态与营养菌丝不同,分生孢子梗单生或者松散成束,光滑或粗糙;产孢细胞多芽、深褐色、具有黑色驼峰状的分生孢子脱落痕;分生孢子梭形至倒棒状、长喙状,6-8个横隔,有明显油滴状细胞内含物,有时具顶端粘膜鞘。露兜长喙孢Rostriconidium pandanicola报道为世界淡水环境的新记录。     

Microbiological corrosion of aluminum alloys

Biological corrosion of AD0 quality aluminum and aluminum-based construction materials (alloys V65, D16, and D16T) was studied. Thirteen microscopic fungus species and six bacterial species proved to be able to attack aluminum and its alloys. It was found that biocorrosion of metals by microscopic fungi and bacteria was mediated by certain exometabolites. Experiments on biocorrosion of the materials by the microscopic fungus Alternaria alternata, the most active biodegrader, demonstrated that the micromycete attack started with the appearance of exudate with pH 8–9 on end faces of the samples.     

A conditionally dispensable chromosome controls host-specific pathogenicity in the fungal plant pathogen Alternaria alternata

The filamentous fungus Alternaria alternata contains seven pathogenic variants (pathotypes), which produce host-specific toxins and cause diseases on different plants. Previously, the gene cluster involved in host-specific AK-toxin biosynthesis of the Japanese pear pathotype was isolated, and four genes, named AKT genes, were identified. The AKT homologs were also found in the strawberry and tangerine pathotypes, which produce AF-toxin and ACT-toxin, respectively. This result is consistent with the fact that the toxins of these pathotypes share a common 9,10-epoxy-8-hydroxy-9-methyl-decatrienoic acid structural moiety. In this study, three of the AKT homologs (AFT1-1, AFTR-1, and AFT3-1) were isolated on a single cosmid clone from strain NAF8 of the strawberry pathotype. In NAF8, all of the AKT homologs were present in multiple copies on a 1.05-Mb chromosome. Transformation-mediated targeting of AFT1-1 and AFT3-1 in NAF8 produced AF-toxin-minus, nonpathogenic mutants. All of the mutants lacked the 1.05-Mb chromosome encoding the AFT genes. This chromosome was not essential for saprophytic growth of this pathogen. Thus, we propose that a conditionally dispensable chromosome controls host-specific pathogenicity of this pathogen.     

Alternaria infectoria , a Promising Biological Control Agent for the Fig Wax Scale, Ceroplastes rusci (Homoptera: Coccidae), in Egypt

Alternaria infectoria E . G . Simmons was isolated from naturally infected eggs of the fig wax scale insect , Ceroplastes rusci L . (Homoptera: Coccidae) , that were showing different degrees of shriveling . This fungus proved to be pathogenic to eggs , nymphs and adults of this pest . The fungus had significant effects on both the mortality and hatchability of the eggs ( P = 0 . 0001) . Three days after exposure to the fungus , nearly one - third (31 . 5%) of the fungus - treated eggs became discolored and 17% showed moderate shrinking but no mortality . Fifteen days post - application , 91% of the fungus - treated eggs were diseased (74 . 8% of them were dead) due to A. infectoria, while no disease developed on the untreated eggs . Hatching decreased by 39 . 6% over a 15 - day period in the fungus - treated eggs compared to the control . Additionally , crawlers hatching from fungus - treated eggs became infected . The fungus seemed to induce crawlers to enter the settling stage . Seventy - two per cent of the fungus - treated crawlers versus 9% of the untreated controls entered the settling stage 6 days after exposure to the fungal inoculum . The highest level of nymphal mortality attributed to A. infectoria occurred when 30% (wet w:v blended mycelium in water containing 0 . 5% w:v Metamucil) inoculum was applied , and a high relative humidity was maintained for the following 48 h . This is the first record of A. infectoria on the fig wax scale and for the genus Alternaria as an entomopatho genic fungus .     

Fungi Isolated from Flue-Cured Tobacco Inoculated in the Field with Storage Fungi

Flue-cured tobacco inoculated in the field with A. amstelodami, A. flavus, A. ochraceus, A. repens, A. ruber, and a species of Penicillium was rarely invaded by these fungi. Regardless of inoculum, the predominant fungi reisolated from green tissue were species of Alternaria and Cladosporium. After curing, A. repens, A. niger, and species of Alternaria and a species of Penicillium were the most commonly isolated fungi. The fungus used as inoculum was not the predominant fungus reisolated from green or cured tissue. Conditions during handling and storage prior to marketing probably determine when storage fungi become associated with the leaf and which species becomes predominant.     

Cryptophiale sphaerospora sp. nov. occurring onJanetia synnematosa

Cryptophiale sphaerospora sp. nov. is described and illustrated based on a single collection attached to a synnematous fungus,Janetia synnematosa, from a dead bamboo culm. It differs from other species ofCryptophiala in having spherical to subspherical conidia and a cerebroid layer of phialides. The overall morohology of this species is smaller than that of previously described species.     

Molecular systematics of citrus-associated Alternaria species

The causal agents of Alternaria brown spot of tangerines and tangerine hybrids, Alternaria leaf spot of rough lemon and Alternaria black rot of citrus historically have been referred to as Alternaria citri or A. alternata. Ten species of Alternaria recently were described among a set of isolates from leaf lesions on rough lemon (Citrus jambhiri) and tangelo (C. paradisi × C. reticulata), and none of these isolates was considered representative of A. alternata or A. citri. To test the hypothesis that these newly described morphological species are congruent with phylogenetic species, selected Alternaria brown spot and leaf spot isolates, citrus black rot isolates (post-harvest pathogens), isolates associated with healthy citrus tissue and reference species of Alternaria from noncitrus hosts were scored for sequence variation at five genomic regions and used to estimate phylogenies. These data included 432 bp from the 5' end of the mitochondrial ribosomal large subunit (mtLSU), 365 bp from the 5' end of the beta-tubulin gene, 464 bp of an endopolygalacturonase gene (endoPG) and 559 and 571 bp, respectively, of two anonymous genomic regions (OPA1-3 and OPA2-1). The mtLSU and beta-tubulin phylogenies clearly differentiated A. limicola, a large-spored species causing leaf spot of Mexican lime, from the small-spored isolates associated with citrus but were insufficiently variable to resolve evolutionary relationships among the small-spored isolates from citrus and other hosts. Sequence analysis of translation elongation factor alpha, calmodulin, actin, chitin synthase and 1, 3, 8-trihydroxynaphthalene reductase genes similarly failed to uncover significant variation among the small-spored isolates. Phylogenies estimated independently from endoPG, OPA1-3 and OPA2-1 data were congruent, and analysis of the combined data from these regions revealed nine clades, eight of which contained small-spored, citrus-associated isolates. Lineages inferred from analysis of the combined dataset were in general agreement with described morphospecies, however, three clades contained more than one morphological species and one morphospecies (A. citrimacularis) was polyphyletic. Citrus black rot isolates also were found to be members of more than a single lineage. The number of morphospecies associated with citrus exceeded that which could be supported under a phylogenetic species concept, and isolates in only five of nine phylogenetic lineages consistently were correlated with a specific host, disease or ecological niche on citrus. We advocate collapsing all small-spored, citrus-associated isolates of Alternaria into a single phylogenetic species, A. alternata.     

生于豆科植物上的链格孢属真菌一新种

报道生于豆科植物沙冬青Ammopiptanthus mongolicus上的链格孢属真菌一新种,沙冬青链格孢Alternaria ammopiptanthi。此种不同于已从豆科植物上报道的5个长喙链格孢种（复喙链格孢A. multirostrata、决明链格孢A. cassiae、猪屎豆生链格孢A. crotalariicola、瓜尔豆链格孢A. cyamopsidis和长喙链格孢A. longirostrata）,主要是其分生孢子的长喙不分枝和孢身细瘦。研究过的模式标本（PSNXAAFS 267852）保存在宁夏农林科学院植物病害标本室。     

生于豆科植物上的链格孢属真菌一新种

报道生于豆科植物沙冬青Ammopiptanthus mongolicus上的链格孢属真菌一新种,沙冬青链格孢Alternaria ammopiptanthi。此种不同于已从豆科植物上报道的5个长喙链格孢种(复喙链格孢A.multirostrata、决明链格孢A.cassiae、猪屎豆生链格孢A.crotalariicola、瓜尔豆链格孢A.cyamopsidis和长喙链格孢A.longirostrata),主要是其分生孢子的长喙不分枝和孢身细瘦。研究过的模式标本(PSNXAAFS267852)保存在宁夏农林科学院植物病害标本室。     

Pythiogeton zizaniae, a new species causing basal stalk rot of water bamboo in Taiwan

A new species, Pythiogeton zizaniae, was isolated from diseased water bamboo (Zizania latifolia) in central Taiwan. The organism formed a colony with scanty mycelia and mycelial aggregates on rye-water bamboo medium. Special treatments were required for production of sporangia which were terminal, noncaducous and mostly ovoid. Chlamydospores were absent. The fungus was homothallic. Oogonia produced on V-8 water bamboo medium in water were mostly globose to subglobose and each was attached with a club-shaped, monoclinous antheridium by the base of the oogonium stalk. Oospores were plerotic and globose to subglobose. Py. zizaniae caused death of water bamboo suckers but did not infect seedlings of corn, rice, wheat, sorghum, cucumber, tomato, soybean or water spinach. It also did not affect cucumber and tomato fruit, carrot roots or potato tubers.     

Isolation and characterization of microsatellite markers from the phytopathogenic fungus Alternaria dauci

Eleven polymorphic microsatellite markers were isolated from the necrotrophic phytopathogenic fungus Alternaria dauci based on enriched genomic libraries. In order to assess allelic variability, the microsatellite loci were analysed in a collection of 43 isolates. The number of detected alleles in 11 loci ranged from two to 24 (mean 10.4). Test of cross-species amplification and sequencing of the resulting amplicons showed that some of these microsatellites could be used in different species such as Alternaria solani, Alternaria bataticola and Alternaria zinniae.