核酸技术在立枯丝核菌分类与生态学研究中的应用

立枯丝核菌是一种传播广、危害大的土传病原菌,对其展开的研究已涉及各个方面并逐渐深入,近几年借助于核酸技术对其所展开的研究更成为热点。对核酸技术在立枯丝核菌的分类学研究(主要包括G Cmol%含量测定、核酸杂交、各种DNA指纹技术、特异PCR扩增、测序DNA的序列分析)、监测群体动态变化的生态学研究(实时荧光PCR技术)中的应用作一简要的介绍。     

The question of cosmopolitanism in the deep-sea ostracod fauna: the example of the genus Pedicythere

Deep-sea Pedicythere species which had been earlier considered as pan-abyssal in distribution are shown to be composite species including similar, but separate species in the Pacific, Indian and Atlantic oceans. Morphology and distribution of Pedicythere are analysed. A key to well-described Cenozoic species and forms in open nomenclature which are referred to Pedicythere is presented, together with an annotated checklist of species. Five new species of Pedicythere are described from the South China Sea: P. hirundo sp. nov., P. gibbera sp. nov., P. dentata sp. nov., P. arator sp. nov. and P. nivea sp. nov.     

A revised classification of the higher taxa of the Ostracoda (Crustacea)

Focusing on palaeontological data from the literature of the last four decades, a new classification of the Ostracoda is outlined. The superorder Podocopomorpha is accepted as a mantle term for the ‘P-orders’ Palaeocopida, Punciocopida, Platycopida and Podocopida; its counterpart are the Myodocopomorpha (Cypridinida, Halocypridida and ? Leperditicopida). The Podocopida comprise the suborders Bairdiocopina, Cytherocopina, Sigilliocopina, Cypridocopina, Darwinulocopina and Healdiocopina (n.;=Metacopina s.s.). The non-calcifying ostracodomorph arthropods (Archaeocopida and Phosphatocopida) of the Early Palaeozoic, now excluded from the Ostracoda by many authors, are also considered briefly.     

姜科植物研究进展

姜科植物在种类、外部性状及内部解剖等方面具有高度的复杂性,其传粉方式也显示出了丰富的多样性。因此,姜科植物的研究对姜目乃至单子叶植物的系统与进化研究,都具有十分重要的意义。本文综述了国内外有关姜科植物在分类学、系统学、解剖学、花器官发生学和繁殖生物学等方面的研究和进展,以期能为该类群的系统研究提供一定的帮助。     

A new species of Oxalis section Corniculatae (Oxalidaceae) from the Balearic islands

A new species, Oxalis ferae Llorens, Gil & Cardona (Oxalidaceae) from the Balearic islands (Spain) is described and illustrated. It is considered to be endemic to Mallorca. The morphological differences between the more closely related taxa of Oxalis section Corniculatae are discussed. IUCN threatened category and observations on the ecology of the populations are noted.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 489–493.     

孔雀活化素基因(activin)ßA 亚基成熟肽序列的分子克隆及其对白孔雀起源与分类的佐证分析

参考已经克隆的活化素(activin)基因βA亚基成熟肽序列,设计一对兼并引物,从绿孔雀(pavo muticus)、蓝孔雀(pavo cristatus)和白孔雀基因组中克隆到活化素基因βA亚基成熟肽序列。测序结果表明,活化素基因βA亚基成熟肽序列长345bp,编码115个氨基酸。序列分析表明,蓝孔雀与绿孔雀核苷酸同源性为98.0%,而蓝孔雀与白孔雀核苷酸同源性为98.8%。NCBI收索结果显示,活化素基因βA亚基成熟肽序列在不同物种间都非常保守。氨基酸功能位点分析表明,活化素βA亚基成熟肽可能在细胞信号传递过程中发挥了很重要的作用。另外,利用活化素基因βA亚基成熟肽序列构建了三种孔雀的限制性酶切图谱及系统发生树。结果显示,白孔雀与蓝孔雀的亲源关系比与绿孔雀的亲源关系近。我们认为,白孔雀来源于蓝孔雀,很可能是蓝孔雀一个杂交后代或亚种,而不是人们通常所认为的仅仅是蓝孔雀的一个颜色突变体。Abstract: The sequences of activin geneβA subunit mature peptide have been amplified from white peafowl, blue peafowl (pavo cristatus) and green peafowl (pavo muticus) genomic DNA by polymerase chain reaction (PCR) with a pair of degenerate primers. The target fragments were cloned into the vector pMD18-T and sequenced. The length of activin gene βA subunit mature peptide is 345bp, which encoded a peptide of 115 amino acid residues. Sequence analysis of activin gene βA subunit mature peptide demonstrated that the identity of nucleotide is 98.0% between blue peaflowl and green peafowl, and the identity of that is 98.8% between blue peaflowl and white peafow. Sequences comparison in NCBI revealed that the sequences of activin geneβA subunit mature peptides of different species are highly conserved during evolution process. In addition, the restriction enzyme map of activins is high similar between white peafowl and blue peafowl. Phylogenetic tree was constructed with Mega 2 and Clustalxldx software. The result showed that white peafowl has a closer relationship to blue peafowl than to green peafowl. Considered the nucleotide differences of peafowls’ activin geneβA subunit mature peptides, a highly conserved region, we supported that white peafowl was derived from blue peafowl, and it is more possible the hybrid but just the product of color mutation, or maybe as a subspecies of Pavo genus.     

Morphological and Molecular Characterization of Longidorus americanum n. sp. (Nematoda: Longidoridae), a Needle Nematode Parasitizing Pine in Georgia

We describe and illustrate a new needle nematode, Longidorus americanum n. sp., associated with patches of severely stunted and chlorotic loblolly pine, (Pinus taeda L.) seedlings in seedbeds at the Flint River Nursery (Byromville, GA). It is characterized by having females with a body length of 5.4-9.0 mm; lip region slightly swollen, anteriorly flattened, giving the anterior end a truncate appearance; long odontostyle (124-165 µm); vulva at 44%-52% of body length; and tail conoid, bluntly rounded to almost hemispherical. Males are rare but present, and in general shorter than females. The new species is morphologically similar to L. biformis, L. paravineacola, L. saginus, and L. tarjani but differs from these species either by the body, odontostyle and total stylet length, or by head and tail shape. Sequence data from the D2-D3 region of the 28S rDNA distinguishes this new species from other Longidorus species. Phylogenetic relationships of Longidorus americanum n. sp. with other longidorids based on analysis of this DNA fragment are presented. Additional information regarding the distribution of this species within the region is required.     

Morphological and Molecular Characterization of a New Root-Knot Nematode,Meloidogyne thailandica n. sp. (Nematoda: Meloidogynidae), Parasitizing Ginger (Zingiber sp.)

A root-knot nematode Meloidogyne thailandica n. sp. was discovered on roots of ginger (Zingiber spp.) intercepted from Thailand in October 2002 by the U.S. Department of Agriculture Animal and Plant Health Inspection Service at the port of San Francisco. Comparison by light microscopy (LM) and scanning electron microscopy (SEM) to five other morphologically related species (M. incognita, M. arenaria, M. microcephala, M. megatyla, and M. enterolobii) revealed that the new species differs from these by one or more of the following: body, tail and hyaline tail length, shape of head, tail and tail terminus of second-stage juveniles; stylet length and shape of spicules in males; perineal pattern, stylet length and shape of knobs in females. The distinctive perineal pattern is oval to rectangular, with smooth to moderately wavy and coarse striae, and with characteristic radial structures present underneath the pattern area; the dorsal arch is high, sometimes round to rectangular, and striae in and around the anal area form a thick network-like pattern interrupted by lateral lines and large phasmids. Second-stage juveniles have a long, slender tail and long, gradually tapering hyaline tail region ending in a rounded terminus. Male spicules commonly have an acutely angled shaft with a bidentate terminus. Molecular data from the ribosomal large subunit D3 expansion segment revealed four haplotypes, two of which were unique and distinguish M. thailandica n. sp. from M. arenaria, M. incognita, and M. javanica.     

Bursaphelenchus anatolius n. sp. (Nematoda: Parasitaphelenchidae), an Associate of Bees in the Genus Halictus

Bursaphelenchus anatolius n. sp., a phoretic associate of Halictus bees from Ankara, Turkey, is described and illustrated. Bursaphelenchus anatolius n. sp. is closest to B. kevini, which is phoretically associated with Halictus bees from the Pacific Northwest. Bursaphelenchus anatolius n. sp. and B. kevini appear to be sister taxa based upon several shared morphological features, similar life histories involving phoresy with soil-dwelling Halictus bees, and molecular analysis of the near-full-length small subunit rDNA, D2D3 expansion segments of the large subunit rDNA, and partial mitochondrial DNA COI. Bursaphelenchus anatolius n. sp. can be differentiated from all other species of Bursaphelenchus based upon spicule morphology. The paired spicules are uniquely shaped and ventrally recurved, and both B. anatolius n. sp. and B. kevini possess extending flaps that open when the spicules are protracted beyond the cloaca. Population growth of B. anatolius n. sp. was measured at 23 °C in the laboratory on cultures of the fungus Monilinia fructicola grown on lactic acid-treated, 5% glycerol-supplemented potato dextrose agar. Nematode population densities rapidly increased from 110 to about 110,000/9-cm-diam. dish within 21 days.