The enigmatic Squamanita odorata (Agaricales, Basidiomycota) is parasitic on Hebeloma mesophaeum

Squamanita odorata is an agaric which is parasitic on unrecognizable, previously unidentifiable sporophores of a fungal host that is transformed into galls at the bases of the parasite's sporophore. Amplification and sequencing portions of the nuclear (ITS) and mt rDNA from three samplings originating from two sites (from France and from Switzerland) demonstrate that the galls produce sequences that are identical to that of co-occurring Hebeloma mesophaeum. This demonstrates that S. odorata is a biotrophic parasite on Hebeloma mesophaeum.     

Arthromyces and Blastosporella, two new genera of conidia-producing lyophylloid agarics (Agaricales, Basidiomycota) from the neotropics

Two new genera encompassing three new species of lyophylloid agarics that produce conidia on the basidiomata are described. Arthromyces is a genus comprised of two very different arthrospore-producing mushroom species found in the Greater Antilles and Central America. Blastosporella is a monotypic genus with spherical balls of blastospores covering the pileus surface with age and is known from Hispaniola and Colombia. A key to the species of Arthromyces is included.     

采自吉林省敦化市的2个蘑菇目(Agaricales)新记录种

【背景】在中国吉林省延边朝鲜族自治州敦化市寒葱岭红叶谷进行大型真菌资源调查的过程中发现了2个物种。【目的】确定这2个物种的分类地位。【方法】采集大型真菌标本,对其形态进行详细观察和描述,并提取DNA、测定rDNA ITS序列,基于最大似然法和贝叶斯法构建分子系统发育树。【结果】鉴定结果表明,这2个蘑菇目物种分别是径边刺毛鬼伞(Tulosesus callinus)和拉氏红菇(Russula lakhanpalii),在形态上与原始描述高度吻合,系统发育分析也验证了形态学的鉴定结果。【结论】拉氏红菇(R. lakhanpalii)系中国首次报道,径边刺毛鬼伞(T. callinus)为吉林省新记录种。     

Reproductive modes in the epixylic hepatic Anastrophyllum hellerianum

The frequency and dynamics of sexual and asexual reproduction were investigated in a dioecious epixylic hepatic, Anastrophyllum hellerianum, which has declined in recent decades in Finland as a consequence of forestry practices. In our investigation asexual reproduction by gemmae was the dominant mode of reproduction and specialised gemmiparous shoots were present in all colonies studied. The proportions of dead shoots were considerably higher among sex-expressing than among non-sexexpressing shoots. Our results suggest that lower reproductive investment is required for asexual than for sexual reproduction. For instance, no trade-off is detected between asexual reproduction and survival of the gemmiparous shoots in A. hellerianum. Sexual reproduction occurred only in 12% of the colonies and it was promoted by the following factors: medium shoot density, high proportion of sex-expressing shoots, an even sex ratio and very short distances between individuals representing opposite sexes. The ratio of dead males to dead females was significantly female-biased, which suggests higher mortality among female shoots. At the level of individual shoots, more spores than gemmae were produced. However, as a consequence of the low frequency of sporophyte-bearing shoots, gemma production highly exceeded spore production at the colony level. Furthermore, cultivation tests of the propagules showed that gemmae germinate faster than spores.     

孢子发生在真菌菌种鉴定中的作用

孢子发生（conidiogenesis）一词指的是孢子从产孢细胞发生的过程,即产孢细胞产生孢子当时和孢子产生后的发展形态。Hughes于1953年将观察孢子发生方式用于半知菌（fungi imperfecti）的鉴定。半知菌过去指有性阶段不清楚的真菌,现称丝裂孢子真菌（mitosporic fungi）。由于这组真菌的形态变化多样,鉴定存在困难。早期使用的是Saccardo的分类法对其进行分类（见半知菌图解）。该体系将孢子分为七类：单孢（Ameroporae）、双孢（Didynoporae）、多孢（Phragmosporae）、砖格（Dictyosporae）、螺旋（Helicosporae）、线状（Scolicosporae）、星状（Starosporae）。这种方法只是比较机械地对孢子特点进行观察,没有结合其产孢过程和产孢细胞的特点。1979年Cole和Samson应用电镜观察了孢子发生的情况。1983年Minre等用光镜和电镜观察并总结了分生孢子产生全部过程。de Hoog等主编的《Atlas of Clinical Fungi》一书中也介绍了孢子发生在真菌鉴定中的作用。我们在20世纪80～90年代也以暗色真菌为切人点全面观察和研究了孢子发生的全部过程。为了提高医学真菌的实验室鉴定水平,现结合我们的经验将孢子发生在真菌菌种鉴定中的作用介绍如下。     

The distribution and systematic relevance of the androecial character oligomery

Localization of the stamens can be approached by a preliminary distinction between two characters, oligomery and polymery, occurring in two different groups of taxa, respectively the oligomerous complex and the polymerous complex. Oligomery is described by four character states standing in a close semophyletic relationship: diplostemony, obdiplostemony, haplostemony and obhaplostemony. Each character state is analysed for its distribution and systematic value. Diplostemony is the synapomorphic character state for the oligomerous line and has arisen once from a polymerous ancestor or in parallel in different lines. Obdiplostemony arises ontogenetically in three different ways. Loss of one whorl leads either to obhaplostemony, or haplostemony; both character states are believed to represent evolutionary steps of no-return. Secondary increases and reductions of the stamens within a whorl are seen as expressions of the intrinsic variability of the character states and should not be homologized with them. Stamen numbers can be increased by the building-up of complex primordia or by secondary receptacular growth. Reductions of stamens affect one or two whorls of stamens and are caused by lack of space, interactions with the gynoecium and zygomorphy. The distribution of the different character states of oligomery is presented on Dahlgrenograms and the androecia of a number of families and their relationships are discussed. The interactions between oligomery and polymery are analysed as guidelines for a global phylogeny of the Magnoliatae.     

The distribution and systematic relevance of the androecial character polymery

RONSE DECRAENE L. P. AND SMETS E. F., 1993. The distribution and systematic relevance of the androecial character polymery . Two characters, viz. oligomery and polymery, have been previously proposed to circumscribe the localization of the androecium. Their distribution is more or less correlated with two groups of taxa: polymery is found in Magnoliidae, Caryophyllidae, Liliatae and part of Hamamelidae; oligomery is found in Dilleniidae, Rosidae, part of Hamamelidae and Asteridae. Polymery can be described by a number of character states, which are presented in a semophyletical scheme. Spiral polyandry, i.e. a multistaminate and spiral androecium, represents the plesiomorphic condition for all Magnoliophytina and is restricted to the polymerous group. Cyclization, induced by an arrangement of the perianth in trimerous whorls and a fractioning of the continuous plastochron, leads to polycycly, i.e. an arrangement of the stamens in numerous cycles; the outer stamens are usually inserted as pairs or in alternation with the inner perianth parts. From this configuration reduction series in different groups result in androecia with a lower number of stamen whorls (such as tetracycly, tricycly, dicycly and (ob)monocycly). The transition from trimery to pentamery induces a derived stamen configuration by the merging of two tepaline whorls and the loss of some stamens. für ther reductions accompanied evolution in trimerous flowers and led to conditions resembling diplostemony as observed in Caryophyllaceae, some Hamamelidaceae and Ranunculaceae. Secondary increases, as well as reductions of stamens within a whorl must be regarded as gradual variations of each character state. Different trends affecting the number and position of the stamens can globally be traced along different lines. Polymery is consistent with other floral characters, such as the nature of perianth, vasculature (axial and cortical systems) and merosity. The androecium of a number of families and their relationships are discussed.     

The mouth apparatus of the Cambrian gilled lobopodian Pambdelurion whittingtoni

Omnidens is a large feeding apparatus composed of circlets of teeth, first documented from the early Cambrian of China. Originally interpreted as the oral cone of a radiodontan, it was later reinterpreted as the introvert of a priapulan. In both cases the Omnidens mouthparts underpinned estimates of gigantic (c. 2 m) body size. Recent evidence has been used to suggest that pharyngeal teeth and radially‐arranged oral plates in the stem‐group onychophoran Hallucigenia and the lower stem‐group euarthropod Jianshanopodia are homologous to structures of the introvert in priapulans and other scalidophorans, and are thus primitive characters for moulting animals (Ecdysozoa) as a whole. Here we show that the early Cambrian gilled lobopodian Pambdelurion whittingtoni from Sirius Passet, Greenland, possesses a mouth apparatus identical to Omnidens, being composed of the same three zones with detailed similarities of sclerites in each zone. An oral cone with rings of pharyngeal teeth, radial plates and outer scalid‐like plates are ecdysozoan characters retained in the euarthropod stem group. Omnidens from China probably belongs to an unrecognized Pambdelurion‐like animal rather than being part of a giant priapulan.     

New fungal genera, Tectonidula gen. nov. for Calosphaeria-like fungi with holoblastic-denticulate conidiogenesis and Natantiella gen. nov. for three species segregated from Ceratostomella

Two morphologically similar groups of ascomycetes with globose to subglobose perithecia, elongate necks, unitunicate asci floating freely at maturity, and hyaline ascospores currently placed in Calosphaeria s. lat. and Ceratostomella s. lat., respectively, are studied. The Calosphaeria-like fungi have groups of perithecia growing between cortex and wood, arranged in circular groups with converging necks and piercing the cortex in a common point; the asci with a shallow apical ring and U- to horseshoe-shaped hyaline ascospores are compared with Calosphaeria pulchella, the type species of the genus. Conidiogenesis of the investigated Calosphaeria-like fungi is holoblastic-denticulate; ramichloridium-like and sporothrix-like conidiophores and conidia were formed in vitro. Ascospore and ascus morphology, structure of the ascal apex, ascogenous system, mode of conidiogenesis and the large subunit rRNA sequences of this group differ considerably from C. pulchella and both groups are unrelated. Thus a new genus, Tectonidula, is described with two accepted species, T. hippocrepida and T. fagi; they are separated by ascospore and ascus morphology and holoblastic-denticulate conidiogenesis from the core species of Calosphaeria. The placement of Tectonidula among perithecial ascomycetes is discussed. The relationship of Tectonidula with Barbatosphaeria and two ramichloridium-like hyphomycetous genera Rhodoveronaea and Myrmecridium is investigated. Three species formerly attributed to Ceratostomella are studied. The revision of the herbarium type specimen and fresh material of Ceratostomella ligneola revealed that it is conspecific with Ceratostomella ampullasca and Ceratostomella similis. The LSU phylogeny clearly separated C. ligneola from Ceratostomella s. str. and morphologically similar Lentomitella. On the basis of molecular sequence data and detailed comparison of morphology of asci, ascospores and ascogenous system the genus Natantiella is described for C. ligneola with C. ampullasca and C. similis as its synonyms. Natantiella produced sterile mycelium in vitro.     

The distribution and the systematic relevance of the androecial characters oligomery and polymery in the Magnoliophytina

In the system of classification sensu Cronquist, the division between the two subclasses Dilleniidae and Rosidae relies on only a few characters. The major distinguishing character is the occurrence of centripetal or centrifugal sequence of stamen development. We question not only the application and the value of this character, but also the maintenance of the Rosidae and Dilleniidae as separately derived natural taxa, because of the lack of solid distinguishing criteria. We have studied the staminal characters in the 192 families of the Dilleniidae and the Rosidae, using Dahlgren's classification diagram.
The study focussed on the following androecial characters: 1) polyandry; i.e. spiral polyandry, complex polyandry (viz. centrifugal, centripetal and lateral polyandry) and cyclic polyandry 2) diplostemony and obdiplostemony 3) haplostemony and obhaplostemony.
In our proposal only two characters are maintained, namely oligomery (diplostemony s.l.) and polymery (true polyandry s.l.), both having a number of character states. Polyandry, as it has been described up to now, is not to be regarded as homologous in all Magnoliophytina. Both characters correspond to two different lines within the Magnoliatae. In addition, the division between the Dilleniidae and Rosidae sensu Cronquist is no longer tenable.
Finally, a number of modifications of Dahlgren's diagram are suggested and a division of the Magnoliophytina in a polymerous group and an oligomerous group is proposed. The Dilleniidae-Rosidae complex is included in the oligomerous group.     

The role of the genesnrf EFG andccmFH in cytochromec biosynthesis inEscherichia coli

It has been suggested that two groups ofEscherichia coli genes, theccm genes located in the 47-min region and thenrfEFG genes in the 92-min region of the chromosome, are involved in cytochromec biosynthesis during anaerobic growth. The involvement of the products of these genes in cytochromec synthesis, assembly and secretion has now been investigated. Despite their similarity to other bacterial cytochromec assembly proteins, NrfE, F and G were found not to be required for the biosynthesis of any of thec-type cytochromes inE. coli. Furthermore, these proteins were not required for the secretion of the periplasmic cytochromes, cytochromec ₅₅₀ and cytochromec ₅₅₂, or for the correct targeting of the NapC and NrfB cytochromes to the cytoplasmic membrane. NrfE and NrfG are required for formate-dependent nitrite reduction (the Nrf pathway), which involves at least twoc-type cytochromes, cytochromec ₅₅₂ and NrfB, but NrfF is not essential for this pathway. Genes similar tonrfE, nrfF andnrfG are present in theE. coli nap-ccm locus at minute 47. CcmF is similar to NrfE, the N-terminal region of CcmH is similar to NrfF and the C-terminal portion of CcmH is similar to NrfG. In contrast to NrfF, the N-terminal, NrfF-like portion of CcmH is essential for the synthesis of allc-type cytochromes. Conversely, the NrfG-like C-terminal region of CcmH is not essential for cytochromec biosynthesis. The data are consistent with proposals from this and other laboratories that CcmF and CcmH form part of a haem lyase complex required to attach haemc to C-X-X-C-H haem-binding domains. In contrast, NrfE and NrfG are proposed to fulfill a more specialised role in the assembly of the formate-dependent nitrite reductase.     

不同经营方式下毛竹光合特性分异研究

林木经营方式与林内光照、温度、水分及养分格局关系密切,影响到植株的光合水平。为探明毛竹对不同经营方式的光合响应特性,以安徽省黄山区3种经营方式下的5类毛竹林为对象开展研究,即:粗放经营(Ⅰ)、一般经营(Ⅱ)和集约经营(Ⅲ-挖冬笋量10%—15%,、Ⅳ-挖冬笋量15%—20%、Ⅴ-挖冬笋量约10%,每年9月施氮肥)。结果表明:1)不同经营方式下毛竹的叶面积指数(LAI)和SPAD值间存在显著差异,随经营程度的增加,LAI和SPAD值波动增大。2)光响应曲线变化趋势基本一致,非直角双曲线拟合良好,方程决定系数均大于0.96,随光合有效辐射(PAR)增强,净光合速率(P_n)、气孔导度(C_d)、蒸腾速率(T_r)、胞间二氧化碳浓度(C_i)随之降低,非集约经营(Ⅰ、Ⅱ)的总体变化水平高于集约经营下的Ⅳ和Ⅲ,但集约经营下的Ⅴ则与Ⅰ、Ⅱ趋势更接近,说明适当补充养分(Ⅴ)的集约经营能有效提高毛竹对光能的利用能力。3)光饱和点(LSP)、光补偿点(LCP)和暗呼吸速率(R_d)3个参数均最大或最小的两种经营方式下,毛竹林具较高的适应性,表现为最大净光合能力(P_(nmax))显著高于其它经营方式毛竹林,由此推断,粗放经营(Ⅰ)或有效补充林地养分的集约经营(Ⅴ)的毛竹具有较高的光合能力。     

The relation of the genes envA and ftsA in Escherichia coli

Summary The sequence of three genes involved in cell division in E. coli has been determined to be ftsA-envA-azi by three-point transduction experiments. An ftsA envA double mutant strain forms filaments at the restrictive temperature of 42° C, and not chains, but, like the chain forming envA parent strain, is hypersensitive to rifampicin.