大亚基rRNA基因D1/D2区序列相同或相似的子囊菌酵母ITS序列比较和核型分析

下面每个组内的酵母菌:I)Candida aaseri和Candida butyri;Ⅱ)Candida boleticola, Candida laureliae和Candida ralunensis;Ⅲ) Candida zeylanoides和Candida krissii以及Ⅳ) Pichia farinosa和Candida cacaoi因具有相同或只有一个碱基差异的大亚基(26S)rRNA基因D1/D2区序列,而被认为属于同一个种。本研究对其ITS序列和电泳核型进行了比较分析。结果表明前3个组内的种具有完全相同的ITS序列,第Ⅳ组的两个种只有1个碱基差异, 但是各组内的核型并不完全一致。第Ⅳ组内的两个种具有完全相同的核型,证实他们属于同一个种。第Ⅱ组内的C.laureliae和C.ralunensis也具有完全相同的核型,可以肯定二者也属于同一个种,该组内的C.boleticola的核型与前二者不完全一样,但染色体分子量范围相似,也可能与前二者属于同一个种。第Ⅰ和Ⅲ组内各种的核型具有明显差异,对组内种间的同物异名关系未提供支持。     

多年卧孔菌属五个中国新记录种

报道了多年卧孔菌属Perenniporia5个中国新记录种。非洲多年卧孔菌Perenniporia africana采自安徽省,孔口表面浅黄色至赭色,且骨架菌丝不分枝;下延多年卧孔菌P.decurrata采自云南省,担子果盖形,具较小孔口和担孢子;椭圆孢多年卧孔菌P.ellipsospora采自云南省,担子果平伏,孔口圆形至多角形,担孢子不平截;硬多年卧孔菌P.inflexibilis采自福建省,担子果盖形,孔口表面灰白至浅褐色,担孢子无色至浅黄色;黄多年卧孔菌P.xantha采自海南省,孔口较小,表面呈黄色,且在KOH试剂中呈深褐色。根据采集的标本材料提供了它们的详细描述和显微结构图。     

Ultrastructure of the labellar epidermis in selected Maxillaria species (Orchidaceae)

The ultrastructure of the labellar epidermis of 13 species of Maxillaria and one hybrid was examined using low-vacuum scanning electron microscopy (SEM). The labellum may be homogeneous and glabrous or papillose, comprising one type of cell only, or heterogeneous with papillae, uniseriate trichomes and/or glands in various combinations. The trichomes are unbranched and multicellular with pointed or truncated tips. Moreover, in some taxa, moniliform trichomes occur, and these are thought to fragment with the formation of pseudopollen. Homogeneous and heterogeneous labellar organization may represent separate evolutionary lines. Preliminary results suggest that labellar features may provide additional taxonomic characters allowing determination of intrageneric affinities.     

A phylogenetic analysis of the Conchostraca and Cladocera (Crustacea, Branchiopoda, Diplostraca)

A computer-assisted cladistic analysis on morphological characters of the Diplostraca (Conchostraca and Cladocera) has been undertaken for the first time. The morphological information has been obtained from literature and transformed into 56 suitable characters. The analysis included 47 ingroup taxa, comprising five conchostracan taxa (four families of the Spinicaudata and the Laevicaudata) and 42 genera of the Cladocera. A detailed character discussion is presented which will be a useful working base for future phylogenetic studies on the group. A number of systematic groups were, with differing degrees of certainty, supported in all 218 equally short trees. These are the Diplostraca, Cladocera, Gymnomera (Onychopoda and Haplopoda), Onychopoda, Podonidae, Cercopagididae, Anomopoda, Daphniidae, Moininae, Scapholeberinae, Chydoridae, Chydorinae and Sididae. The Spinicaudata were only supported on some of the 218 equally short trees while no support was found for the Conchostraca. Two taxa—the Macrothricidae and Aloninae—were relatively strongly indicated to be paraphyletic. A suggested classificatory hierarchy, without indication of absolute rank, is presented.     

Distribution and population dynamics of Porphyra (Bangiales, Rhodophyta) in the southern Western Cape, South Africa

Although Porphyra is commercially farmed in many countries, in South Africa only small harvests of wild populations for sale as nori have been carried out. The discovery that Porphyra improves growth of South African abalone (Haliotis midae) farmed inland-based tanks has led to increased pressure to harvest wild populations. This paper reports on a survey of the distribution and seasonality of Porphyra in the southern Western Cape. Porphyrawas present at all sites surveyed, and showed considerable temporal variation. A significant amount of the Porphyra present is in reserves and therefore protected from harvesting. Close rexamination of one site revealed seasonal populations of Porphyra that occupied different niches dependent on season. Recruitment peaked in spring and autumn, leading to dense summer and winter populations. Summer populations generally grew lower in the eulittoral than winter populations. No pattern in the mortality of larger thalli wasde tected, though sporeling mortality was high following recruitment peaks. Although it seems that most sites in the southern Western Cape are suitable for harvesting, the taxonomy of the genus in the region urgently needs revision if populations are to be appropriately managed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Apolipophorin II/I, Apolipoprotein B, Vitellogenin, and Microsomal Triglyceride Transfer Protein Genes Are Derived from a Common Ancestor

Large lipid transfer proteins (LLTP) are nonexchangeable apolipoproteins and intracellular lipid-exchange proteins involved in the assembly, secretion, and metabolism of lipoproteins. We have identified contiguous conserved sequence motifs in alignments of insect apolipophorin II/I precursor (apoLp-II/I), human apolipoprotein B (apoB), invertebrate and vertebrate vitellogenins (VTG), and the large subunit of mammalian microsomal triglyceride transfer protein (MTP). Conserved motifs present in the N-terminal part of nonexchangeable apolipoproteins encompass almost completely the large subunit of MTP, suggesting a derivation from a common ancestral functional unit, termed large lipid transfer (LLT) module. Divergence of LLTP from a common ancestor is supported by (1) the statistical significance of the combined match scores obtained after motif-based database searches, (2) the presence of several identical amino acid residues in all LLTP sequences currently available, (3) the conservation of hydrophobic clusters in an α-helical domain, (4) the phylogenetic analysis of the conserved sequences related to the von Willebrand factor D (VWD) module identified in nonexchangeable apolipoproteins, and (5) the presence of four and one ancestral exon boundaries in the LLT and VWD modules, respectively. Our data indicate that the genes coding for apoLp-II/I, apoB, VTG, and the MTP large subunit are members of the same multigene superfamily. LLTP have emerged from an ancestral molecule designed to ensure a pivotal event in the intracellular and extracellular transfer of lipids and liposoluble substances. Received: 8 June 1998 / Accepted: 15 February 1999     

Why the Phylogenetic Species Concept?—Elementary

Although species play a number of unique and necessary roles in biology, none are more important than as the elements of phylogeny, nomenclature, and biodiversity study. Species are not divisible into any smaller units among which shared derived characters can be recognized with fidelity. Biodiversity inventory, assessment, and conservation are dependent upon a uniformly applicable species concept. Species are the fundamental units in formal Linnaean classification and zoological nomenclature. The Biological Species Concept, long given nominal support by most zoologists, forced an essentialy taxonomic problem (what are species?) into a population genetics framework (why are there species?). Early efforts at a phylogenetic species concept focused on correcting problems in the Biological Species Concept associated with ancestral populations, then applying phylogenetic logic to species themselves. Subsequently, Eldredge and Cracraft, and Nelson and Platnick, each proposed essentially identical and truly phylogenetic species concepts that permitted the rigorous recognition of species prior to and for the purposes of phylogenetic analysis, yet maintained the integrity of the Phylogenetic Species Concept outside of cladistic analysis. Such phylogenetic elements have many benefits, including giving to biology a unit species concept applicable across all kinds of living things including sexual and asexual forms. This is possible because the Phylogenetic Species Concept is based on patterns of character distributions and is therefore consistent with the full range of possible evolutionary processes that contribute to species formation, including both biotic and abiotic (even random) factors.     

Three New Species of Nothacrobeles (Nemata: Cephalobidae) from the Mojave Desert, California

Three new species of Nothacrobeles are described from localities in the Mojave Desert, southern California. Nothacrobeles triniglarus n. sp. is characterized by the presence of a long post-vulval sac and three tubular adoral projections. Both N. spatulatus n. sp. and N. nanocorpus n. sp. are smaller than any other known species within the genus. Nothacrobeles spatulatus n. sp. has labial probolae that are short and spatulate without a basal ridge, whereas those of N. nanocorpus n. sp. are flattened and plate-like. Furthermore, N. nanocorpus n. sp. is unique by its extremely short esophageal corpus (less than 25 µm long in adult females) and the small size of its guard processes. An emended diagnosis of the genus is given to accommodate distinctive characteristics of these new species. A table comparing the 11 valid species of Nothacrobeles is presented.     

Study of the Rotatoria‐Fauna of the Littoral of the Rio Branco,South of Boa Vista,Northern Brazil

From a study of the permanent shallow water in the savanna near Boa Vista, Brazil, a littoral sample was brought back by Dr. G.‐O. Brandorff ; Ahrensburg, which he gave me to examine. The analysis of the material, about 50 ml, showed 149 identifiable species as well as some preservative artifacts. Six species were hitherto unknown to that area. They were identified as the following: Cephalodella brandorffi nov. sp., Dicranophorus difflugarium (Penard , 1924), Eothinia triphea (Harring and Myers , 1924), Lecane bulla papillosa nov. ssp., Macrochaetus paggiensae nov. sp., Notommata falcinella (Harring and Myers , 1922), and Habrotrocha pusilla pusilla (Bryce , 1893).