镰刀菌毒素的研究——Ⅲ.T-2毒素产生菌株M-20的生物学特性

镰刀菌属(Fusarium)是真菌中危害性最大的一个菌属之一,其种类多,分布广,寄主范围大,有许多种是作物的重要致病菌,而且有些菌株能产生镰刀菌毒素。Ueno、Mirocha和Ellison等研究三隔镰孢(F.tricinctum)、拟     

镰刀菌毒素的研究 Ⅰ.T-2毒素产生菌株的筛选

<正> 镰刀菌属(Fusarium)是危害性最大的真菌之一,不仅侵染田间作物和库贮谷物,造成经济损失,而且产生毒素,引起人畜镰刀菌毒素中毒。黄曲霉毒素的致癌作用被证实后,更引起世界各国对镰刀菌毒素及其中毒现象的重视(孟昭赫等,1979)。镰刀菌产生的毒素主要是单端孢霉烯族化合物,其中 T-2毒素的毒性最强(Ronald,1981),它能引起兔子皮肤反应和抑制植物种子发芽等生物毒性效应(Burme-istes,1970;Ueno,1971)。国内尚未见人工培养产生 T-2毒素的报告。为给农业、食品卫生和环境保护等方面研究提供科学依据,本文报告 T-2毒素产生菌株的筛选。     

镰刀菌毒素

镰刀菌毒素黄秀琴,吴晶琼（华东师范大学生物系,上海２０００６２）镰孢霉（Ｆｕｓａｒｉｕｍ）也称镰刀菌,它所产生的镰刀菌毒素,不仅能使植物致病,而且还会污染食品和饲料,引起人及动物的中毒甚至死亡,但也有使有害昆虫致死,在生物防治上显示出具有极为重要的作...     

三隔镰刀菌大米培养物产生二苯甲醇的研究

<正> T-2毒素是镰刀菌属三隔镰刀菌Fusarium tricinctum(Corda)Sacc.的一种次生代谢产物,隶属单端孢霉烯簇毒素。发霉大米中毒症及豆荚中毒症等均与单端孢霉烯簇毒素有关。张树荣等从真菌培养物M-20中提取T-2毒素成功,我们对其     

串珠镰刀菌胶孢变种的玉米培养物对雏鸭毒性的病理学观察

<正> 串珠镰刀菌胶孢变种是玉米等谷物上的常见病原菌之一,该菌可产生对动物有害的毒素——串珠镰刀菌素(moniliformin)(Buck et al.,1979:Burmeister et al.,1979;Cole et al.,1973)。最近的研究发现,串珠镰刀菌胶孢变种的玉米培养物还可引起实验性马属动物脑白质软化症(Equine leucoence-phalomalacia)(辛德颐,1987),更引起了人们对该菌的重视。为了进一步研究串珠镰刀菌胶孢变种的毒性,特别是为将来研究其引起马属动物脑白质软化症的致病毒素及其机理提供依据,本实验应用曾引起实验性马属动物脑白质软化症的串珠镰刀菌胶孢变种LBFMV 14的玉米培养物(辛德颐,1987),按不同的比例与雏鸭饲料混合,饲喂1日龄北京鸭,观察其中毒死亡情况和病理变化。     

镰刀菌属一个中国新记录种

从山西省13个主要土壤类型的1 012个土壤样品中分离出镰刀菌333株,依据布斯的镰刀菌属分类系统鉴定其中1株为中国新记录种——柔毛镰刀菌(Fusarium flocciferum Corda),并对其进行描述和讨论。菌种保存于山西农业大学农学院植物病理实验室。     

T-2毒素遗传毒性作用的初步研究

T-2毒素是一种可由三线镰刀菌,拟支孢镰刀菌、梨孢镰刀菌等产生的单端孢霉素,与食物中毒性白细胞缺乏症(Alimentary toxicaleukia,ATA)的发生有关。据报道,T-2毒素可以诱导人的成纤维细胞非程序DNA合成增高,引起地鼠骨髓细胞和人外周血淋巴细胞染色体畸变,导致大鼠淋巴细胞的DNA单链断裂,还可以使人胎儿食管上皮     

镰刀菌真菌毒素产生与调控机制研究进展

镰刀菌是一种重要的植物病原菌,给世界范围内农作物生产带来巨大破坏。除导致产量下降外,由其产生的镰刀菌真菌毒素能够污染农产品品质,给动物和人类食物安全造成严重隐患。单端孢霉烯族毒素（Trichothecenes）、伏马菌素（Fumonisin）和玉米赤霉烯酮（Zearalenone）是三种最重要的镰刀菌真菌毒素。镰刀菌真菌毒素的生物合成与生产受到体内一系列相关功能基因的调控;此外,pH值、碳氮比等环境条件也能影响真菌毒素的产量。本文简述了镰刀菌真菌毒素在产生机理、主要分类、致病性以及调控因素等方面的研究进展。     

单端孢霉烯族毒素的产生及分子调控机制

禾谷镰刀菌复合种(Fusarium graminearum species complex,FGSC)引起的赤霉病是小麦生产上危害最为严重的病害之一。赤霉病除了造成减产外,感病籽粒中含有多种镰刀菌毒素,如单端孢霉烯族的呕吐毒素,可引起人畜中毒和重大疾病,给食品安全构成严重威胁。过去20年,随着禾谷镰刀菌全基因组序列的公布和遗传转化体系的成熟,禾谷镰刀菌Fusarium graminearum的功能基因组学的研究取得了较大进展,单端孢霉烯族毒素的产生、调控机制及网络研究成为热点。本文综述国内外单端孢霉烯族毒素的生物合成和分子调控机制,包括合成基因簇及决定不同产毒化学型的基因、产毒调控元件、环境因子调控产毒的分子机制,可为小麦抗赤霉病的育种提供新思路,为新型药剂的研发提供分子靶标,为赤霉病的持续防控和毒素污染的有效治理提供理论依据。     

燕麦镰刀菌GD-2毒素对野燕麦的除草活性研究（英文）

评价了燕麦镰刀菌GD-2毒素对野燕麦的除草活性潜力。毒素对野燕麦种子萌发抑制试验表明,当毒素浓度达到5 mg/mL时,对野燕麦种子的萌发抑制效果达77.54%,在相同浓度下,对野燕麦种子胚根的抑制效果高于对胚芽的抑制效果。在温室条件下,毒素处理野燕麦植株后,各个不同处理野燕麦株高和地上部鲜重明显减少,然而,各处理间没有明显差异。用石油醚、氯仿、乙酸乙酯和正丁醇依次萃取燕麦镰刀菌发酵滤液并获得粗提物,其中正丁醇浸提物(5 mg/mL)在离体叶片实验中效果优于其他有机溶剂粗提物。此外,在毒素对10种植物的敏感性实验中,其中稗草和藜表现对燕麦镰刀菌毒素敏感。从燕麦镰刀菌中分离出3个除草活性化合物,且具有相同的紫外吸收峰。当前结果表明燕麦镰刀菌产生的毒素具有开发成为防除野燕麦生物源除草剂的潜力。     

蚜小蜂科的分类研究V．我国首次记述毛盾蚜小蜂属及其─中国新记录种（膜翅目：蚜小蜂科）

在我国福建首次发现蚜小蜂科的毛盾蚜小蜂属ＥｒｉａｐｈｙｔｉｓＨａｙａｔ。本文记述了该属的属征、生物学及其分布,并对中国新记录种东方毛盾蚜小蜂ＥｒｉａｐｈｙｔｉｓｏｒｉｅｎｔａｌｉｓＨａｙａｔ作了描述。     

镰刀菌属一新种──链状镰刀菌

本文描述了镰刀菌属的一个新种——链状镰刀菌,其主要特征小型分生孢子椭圆形,基部平,链状生长。大型分生孢子纺锤形,从多口芽梗长出。文中还讨论了新种与其它镰刀菌的关系。模式标本保藏在中国科学院菌物标本馆（HMAS）。     

The What,Why and How of Primate Taxonomy

Taxonomy has a well-defined role, which is much more than simply stamp-collecting and pigeon-holing. Species are the units of classification, biogeography and conservation; as such they must be defined as objectively as possible. The biological species concept, still widely used in biology, though predominantly by non-taxonomists and all too often misunderstood, is a process-based concept, which offers no criterion for the classification of allopatric populations beyond inference and hypothesis. The phylogenetic species concept—a pattern-based concept—is as nearly objective as we are likely to get. Amount of difference is not a criterion for recognizing species. It is not possible to insist on monophyly at the specific level, but it is mandatory for the higher categories (genus, family, etc.). The rank we assign to a given supraspecific category should be determined by its time depth.     

中国蘑菇属新种和新记录种

本文报道我国蘑菇属(Agaricus)43种、2变种。其中新种3个:翘鳞蘑菇Agaricus squ arrosus Li sp. nov.,异鳞蘑菇A. dimorphosquamatus Li sp. nov.,假环柄蘑菇A. lepioti formis Li sp. nov.。本文所研究的全部标本保藏于中国科学院微生物研究所真菌标本名(HMAS)。     

Phylogeography of the finless porpoise and potential implications for the taxonomy of Neophocaena spp.

The finless porpoise (genus Neophocaena) is a poorly known cetacean of great conservation concern. Within its range, from western Pacific to northwestern Indian Ocean, there are currently two species recognized (N. asiaeorientalis and N. phocaenoides), thought to be reproductively isolated since last glacial maximum, with the only sympatric overlap zone in Taiwan Strait. However, the genetic variation across the genus’ distribution has not yet been extensively studied, especially in the Indian Ocean. We performed an exhaustive review of molecular data of the finless porpoise across its range. Neighbor-net networks analyses based on two mitochondrial loci (control region/CR and cytochrome b/cyt b) suggest that finless porpoises from the Indian and Pacific Ocean constitute two distinct clades, well-defined by fixed mutations at both loci. A molecular clock analyses indicate early split (CR: 13.1 Ma, cyt b: 12.9 Ma) between these two oceanic lineages, while spatial genetic analyses further suggest that in the Pacific the divergence was primarily due to the taxon from Japanese waters rather than inter-species divergence across the Taiwan Strait. As extinction risks can be substantially underestimated if threatened species are pooled together with non-threatened, especially in the absence of long-distance migration, we suggest that the present 2-species taxonomy of the genus Neophocaena should be given further examination, with concerted sampling effort in the Western Indian Ocean. More research effort and genomic information is needed before taxonomic revisions can be considered; such further studies are strongly recommended as they may affect the current status classification of the species constituting the genus Neophocaena. Most notably, the narrow-ridged finless porpoise off Japan merits urgent conservation attention.     

Sexual isolation in Drosophila. II. Intraspecific variation in mate recognition systems

A simple behavioral model is used to investigate whether differences in the specific-mate-recognition system (SMRS), occur within species of the Drosophila genus. This model takes into account, and overcomes, the distorting effect of vigor differences on experimental results. Analysis shows significant deviations from the expected values under the assumption of identical SMRSs in around one fifth of the multiple-choice experiments performed with natural strains of twelve different Drosophila species. Different selection procedures raise the number of significant assortative mating results between strains of D. melanogaster and D. pseudoobscura from 3.0% to 32.8%. Finally, sub- or semispecific taxa show variations in their SMRS even more frequently (74.5%). Differences in male vigor and female receptivity are also found. These results show that a classification of Drosophila species based on SMRS stability, as proposed by the “Recognition concept of species”, is virtually impossible.     

Patterns of Fusarium community structure and abundance in relation to spatial, abiotic and biotic factors in soil

Members of the Fusarium genus are important components of many plant–soil systems worldwide and are responsible for many crop diseases. Knowledge of the relative influence of biotic and abiotic factors on this genus is therefore of broad economic and ecological importance. In order to address this issue, we examined Fusarium communities in soils nearby apparently healthy and symptomatic asparagus plants in 50 fields scattered in four agricultural regions of Québec, Canada. Fusarium community structure and abundance were assessed using genus-specific PCR-denaturing gradient gel electrophoresis and CFU counts, respectively. Multivariate statistical analyses were used to detect community patterns related to spatial, abiotic and biotic factors. Results suggested that Fusarium community structure (i.e. the presence and absence of the different Fusarium sequence variants in the samples) in soil is mainly related to biotic factors (arbuscular mycorrhizal fungi and bacterial community structure), whereas Fusarium abundance is more closely related to abiotic factors (mainly clay, organic matter, NH₄, Na and Cu). Some degree of influence of spatial patterns was also observed on both Fusarium community structure and abundance with, for instance, a large regional variation in Fusarium community structure. However, Fusarium community structure was not directly related to the disease status of nearby asparagus plants.     

Mating type sequences in asexually reproducing Fusarium species

To assess the potential for mating in several Fusarium species with no known sexual stage, we developed degenerate and semidegenerate oligonucleotide primers to identify conserved mating type (MAT) sequences in these fungi. The putative alpha and high-mobility-group (HMG) box sequences from Fusarium avenaceum, F. culmorum, F. poae, and F. semitectum were compared to similar sequences that were described previously for other members of the genus. The DNA sequences of the regions flanking the amplified MAT regions were obtained by inverse PCR. These data were used to develop diagnostic primers suitable for the clear amplification of conserved mating type sequences from any member of the genus Fusarium. By using these diagnostic primers, we identified mating types of 122 strains belonging to 22 species of Fusarium. The alpha box and the HMG box from the mating type genes are transcribed in F. avenaceum, F. culmorum, F. poae, and F. semitectum. The novelty of the PCR-based mating type identification system that we developed is that this method can be used on a wide range of Fusarium species, which have proven or expected teleomorphs in different ascomycetous genera, including Calonectria, Gibberella, and Nectria.     

新疆平茶渍属地衣生态分布与地理区系成分分析

根据多年的实地调查资料和前人研究资料,对新疆平茶渍属（Aspicilia）地衣的种类以及它们的分布区、区系特征进行了初步研究。结果表明,分布在新疆的平茶渍属地衣共有33种,主要分布在天山、阿勒泰山、昆仑山和准噶尔盆地。根据它们对环境的适应特征和选择性,将新疆平茶渍属地衣的地理区系划分为广布种、环极北极高山种、环极低北极及北方种、北美东部种、中亚种、中国特有种、分布范围不清楚的种等7种类型。同时把新疆平茶渍属地衣的地理分布区域划分为欧亚森林植物亚区、亚洲荒漠植物亚区、青藏高原亚区等三种分布区域。研究还发现分布在阿勒泰山、天山、昆仑山和准噶尔盆地的平茶渍属主要生长在岩石上面,生长基物比较单一。