The systematic position of the “Theales” from the viewpoint of serology

Species fromthe order “Theales” (Guttiferales) and from the Ericanae (Ebenales, Ericales, Primulales) have been examined using serological comparisons of sets of antigenic specifities (sets of determinants). The results suggest that only antigenic systems derived from species of the Theaceae and Actinidiaceae show serological correspondence of sufficient taxonomical significance towards representatives of Ericanae (except the Ebenaceae). Our results justify a scheme in which the Actinidiaceae and Theaceae occupy a central position with Styracaceae and Sapotaceae placed on one side and the families of the Ericales and Primulales occupying the other. Our serological results show no reason to justify the further existence of the “Theales”, if this is supposed to contain the Guttiferae, Dipterocarpaceae, and Ochnaceae. Further investigations on this will follow. We cannot agree with the recommendation of Takhtajan and Dahlgren to integrate the Actinidiaceae with the Ericales. We would rather place the family ner the Theaceae as most authors do.     

Serology and systematics of the Ebenales and the Theales

The systematic position ofthe Ebenaceae, Sapotaceae, Styracaceae, Ochnaceae, Stachyuraceae, Dipterocarpaceae, Clusiaceae and Hypericaceae has been investigated using serological comparisons of sets of antigenic determinants. The results show that the Sytracaceae and Sapotaceae are undoubtedly more closely associated with the Actinidiaeceae and Theaceae, respectively, than with each other. We found no corresponding determinants betnween antigen systems from the Ebenaceae and systems from any other family whose relations to this family have been proposed. As discovered previously, investigations of antigen systems from the Ochnaceae, Dipterocarpaceae, Stachyuraceae, Clusiaceae and Hypericaceae are against the idea of a natural order “Theales” in which these families, or at least some of them, are combined with the Theaceae and Actinidiaceae. This paper completes our previous investigations which largely support a superorder Ericanae sensu Ehrendorfer and Takhtajan. We propose to include the Actinidiaceae and Theaceae in this superorder, assigning them a central position laong with the Sapotaceae and Sytracaeae on one side and the Primulales and Ericales on the other. Another most interesting finding is that there are corresponding determinants between antigen systems from the members of the Ericanae and representatives of the Polemoniaceae and Loasaceae.     

Homologization of storage proteins from Aquilegia vulgaris and Digitalis purpurea

The separation of the main seed proteins from Aquilegia vulgaris and Digitalis purpurea by means of Sephadex G-200 gel filtration and DEAE-Sephadex ion exchange absorption resulted in remarkably similar patterns. Using gel electrophoresis and serological techniques this phenomenon has been attributed to the predominance of two storage proteins present in each taxon: (a) one main protein in Aquilegia (= nigellin) and in Digitalis (= tubiflorin), each, being similar, but probably not homologous. (b) A secondary protein (= aquilegilin) was identified in both taxa. The distribution of only a few storage proteins in Magnoliophytina (angiosperms) with different serological reactivity (= different primary structure) has been presumed, based upon the data obtained.     

Genetic diversity and phylogenetic relationships of bacteria belonging to the Ochrobactrum-Brucella group by recA and 16S rRNA gene-based comparative sequence analysis

The genetic diversity and phylogenetic interrelationships among 106 Ochrobactrum strains (O. anthropi: 72, O. intermedium: 22, O. tritici: 5, O. oryzae: 2, O. grignonense: 2, O. gallinifaecis: 1, O. lupini: 2), the type strains of the eight Brucella species and other closely related taxa were studied by recA and rrs gene (16S rRNA) comparative sequence analysis. Both markers correctly delineated the various Ochrobactrum species; however, resolution at the subspecies level was considerably higher in the recA gene-based approach. Phylogenetic analyses using neighbor-joining, parsimony, and maximum likelihood algorithms generated trees with similar topologies but the overall branching order, and also the order of the subclades, were not stable in either assay, which could be explained by generally high recA and rrs sequence similarities. Ochrobactrum and Pseudochrobactrum formed separate clades distinct from other Alphaproteobacteria with Bartonella, Agrobacterium, and Rhizobium as the closest relatives. O. gallinifaecis was the most distinct member, when compared to the type species O. anthropi, with rrs and recA similarities of 96.2% and 81.4%. Brucella species were indistinguishable, exhibiting high rrs and recA gene similarities of 98.6% and 85.5% compared with Ochrobactrum intermedium. At the protein level, all RecA sequences among the various Ochrobactrum species and between Ochrobactrum and Brucella were highly similar with only a few amino acid substitutions. O. anthropi and O. tritici were indistinguishable by means of their RecA proteins. A set of initially biochemically classified strains did not cluster within their assigned species and they either grouped within other known species or grouped as potential novel Ochrobactrum species. In further investigations, these strains were reclassified and described as novel species. In summary, Ochrobactrum is a highly diverse genus comprising several novel species. We recommend recA- in addition to rrs gene-analysis for correct species allocation and subtyping of novel Ochrobactrum isolates.     

Natural interploidy hybridization among the key taxa involved in the origin of horticultural chrysanthemums

Understanding hybridization and introgression between natural plant populations can give important insights into the origins of cultivated species. Recent studies suggest differences in ploidy might not create such strong reproductive barriers as once thought, and thus studies into cultivated origins should examine all co-occurring taxa, including those with contrasting ploidy levels. Here, we characterized hybridization between Chrysanthemum indicum L., Chrysanthemum vestitum (Hemsley) Ling and Chrysanthemum vestitum var. latifolium (Zhou & Chen), the most important wild species involved in the origins of cultivated chrysanthemums. We analyzed the population structure of 317 Chrysanthemum accessions based on 13 microsatellite markers and sequenced chloroplast trnL-trnF for a subset of 103 Chrysanthemum accessions. We identified three distinct genetic clusters, corresponding to the three taxa. We detected 20 hybrids between species of different ploidy levels, of which 19 were between C. indicum (4x) and C. vestitum (6x) and one was between C. indicum and C. vestitum var. latifolium (6x). Fourteen hybrids between C. indicum and C. vestitum were from one of the five study sites. Chrysanthemum vestitum and C. vestitum var. latifolium share only one chloroplast haplotype. The substantially different number of hybrids between hybridizing species was likely due to different levels of reproductive isolation coupled with environmental selection against hybrids. In addition, human activities could play a role in the different patterns of hybridization among populations.     

The radiation of the Seicercus burkii complex and its congeners (Aves: Sylviidae): molecular genetics and bioacoustics

Cryptic species of passerine birds lack notable morphological differentiation and can best be identified by molecular and bioacoustic markers. Here we investigate seven cryptic species of the golden-spectacled warbler (Seicercus burkii complex) with respect to territorial song and cytochrome-b (cyt-b) sequences. Their phylogenetic relations to other Seicercus species and to members of the genus Phylloscopus are inferred by the same methods. Three separate lineages of Seicercus are nested within different branches of the molecular Phylloscopus tree. The S. burkii complex is a monophyletic unit comprising seven species (S. burkii s. str., S. whistleri, S. valentini, S. soror, S. omeiensis, S. tephrocephalus and S. affinis). S. xanthoschistos turned out to be a close relative of Phylloscopus davisoni within the P. reguloides group. Two isolated sister taxa, S. grammiceps and S. castaniceps, also branch together with the P. reguloides group. Within the S. burkii complex the overall haplotype and nucleotide diversity is highest in taxa from the Chinese middle and upper mountain belt (S. valentini, S. omeiensis and S. soror), indicating at least partially restricted gene flow in these species. This is explained by the fragmentation of high-altitude habitats in China while in the Himalayas the vicariant species S. whistleri inhabits a more continuous mountain belt at the same altitude. For the Chinese species from medium and high altitudes, past range expansion is indicated by significantly negative Tajima Ds. According to pairwise genetic distances, most species of the S. burkii complex have diverged 5 myr ago, the most recent split between S. burkii and S. tephrocephalus is dated 2 myr ago. Coalescence times for haplotype lineages of the different species range from 9 up to 12 myr, and between 5 and 6 myr for S. burkii and S. tephrocephalus.

Within Seicercus divergence of song features such as frequency parameters and syntax structures correlate with genetic distances between taxa. The three cyt-b lineages of Seicercus correspond to different clusters in a discriminant analysis by acoustic parameters. Common syntax structures of territorial song in the Phylloscopus/Seicercus assemblage are: (1) an introductory element derived from specific calls and (2) a syntax of trills and repeated element groups or a combination of both. There are clear indications that these song structures have repeatedly emerged, were lost or were altered in different branches of the phylogenetic tree at different times. Absolute differences between taxa in frequency parameters or in an acoustic divergence index increase significantly with growing genetic distances. However, due to multiple parallel evolution phylogenetic information provided by single acoustic traits decreases with increasing numbers of taxa involved in the investigation.     

长白山垂直自然带弹尾纲物种概况

以长白山弹尾纲为研究对象, 基于1758‒2022年度发表的分类学和生态学文献资料, 编制了长白山垂直自然带弹尾纲物种名录, 分析了首次发表物种的学者贡献、出版物、发表时间和各属沿海拔梯度的分布情况。本研究共梳理弹尾纲物种92种, 隶属于3目11科46属, 长角䖴目、原䖴目和愈腹䖴目的物种分别占比61%、31%和8%, 其中长角䖴目的等节䖴科(该类群物种数占总体比例, 26%)、长角䖴科(16%)和鳞䖴科(16%)、原䖴目的棘䖴科(26%)是该地区的主要类群。统计的92种长白山弹尾纲物种由36位学者首次定名和报道, 中国学者占主要贡献(33%), 其次为波兰(11%)、瑞典(11%)、俄罗斯(8%)和美国(8%); 相关论文多发表在国际期刊上, Zootaxa是发表的主要期刊。基于海拔梯度的统计发现, 鳞䖴属(Tomocerus)和符䖴属(Folsomia)的物种沿海拔梯度的分布范围最广(海拔800‒1,700 m), 分布在海拔800 m (15个物种)、1,100 m (20个物种)和1,400 m (14个物种)的物种最多。基于以上结果, 本文讨论了长白山弹尾纲分类学现状和发展前景。     

Delimitation of the genus Schizachyrium (Poaceae,Andropogoneae) based on molecular and morphological data

Schizachyrium (Poaceae, Andropogoneae) includes about 60 species distributed in tropical and subtropical regions of the world. In all recent molecular phylogenies of Andropogoneae, representatives of Schizachyrium appear closely related to Andropogon species. The objective of this study was to contribute to the delimitation of Schizachyrium. We performed a phylogenetic study including 38 taxa (>63%) of Schizachyrium, along with representatives of related genera, mainly of Andropogon, yielding a total of 49 taxa. This is the first phylogenetic analysis to include the type species of Schizachyrium, S. condensatum. DNA sequences of two plastid markers (ndhF and trnL-F) were analyzed under Bayesian methods. The results indicate that Schizachyrium is not monophyletic: 26 of the 38 Schizachyrium taxa analyzed are placed in a Schizachyrium s.s. clade that includes the type species of the genus, while 10 taxa are related to Andropogon species and two other species, S. delavayi (from China and India) and S. jeffreysii (from Africa), appear clearly separated. Additionally, 58 morphological characters (41 qualitative and 17 quantitative) were scored for the same 49 taxa and analyzed under the parsimony criterion. Character optimizations showed that (i) the reduced pedicellate spikelets, (ii) with lower glume less than or equal to 0.5 mm wide, (iii) awned, and (iv) without lemma and palea support the Schizachyrium s.s. clade. We propose these four characters as diagnostic features for the delimitation of Schizachyrium s.s.     

不同海拔的三种杓兰属植物与菌根真菌群落组成相关性

本研究采集了四川黄龙沟沿海拔梯度3 170-3 400m上4个不同杓兰居群中3种杓兰植物根,利用克隆文库方法获得菌根真菌ITS序列,研究同一栖息地（黄龙沟）不同海拔梯度和不同杓兰对菌根真菌多样性和群落结构的影响。共得到18个可操作分类单元（OTU）,其中14个OTU隶属胶膜菌科Tulasnellaceae,为优势类群（99.6%）;2个OTU隶属腊壳菌科Sebacinaceae,2个OTU隶属亡革菌科Thelephoraceae。随着海拔升高,西藏杓兰菌根真菌多样性减少,而黄花杓兰和无苞杓兰没有明显变化;海拔对3种杓兰菌根真菌群落结构均无显著影响。3种杓兰之间菌根真菌群落结构差异显著且指示物种互不相同,说明在同一栖息地,杓兰对菌根真菌的偏好性显著影响其菌根真菌群落结构。这些研究结果利于了解环境变化对杓兰属植物菌根真菌区系组成的影响,为进一步探索菌根真菌与杓兰属植物的互作机制奠定基础。     

Chemosystematic Investigation of the Annual Species of Helianthus (Asteraceae)

A total of 43 HPLC peaks tentatively considered to be sesquiterpene lactones was detected from a survey of the 18 taxa (eleven species and seven subspecies) of Helianthus sect. Helianthus using a recently developed microtechnique. All but one of the taxa showed characteristic sesquiterpene lactone patterns with between six and 15 compounds each. H. paradoxus appears to be the only species in the genus in which these compounds are not detectable. Comparison with available reference compounds allowed assignment of structures to 21 of the compounds. Known compounds can be classified into five major structural subtypes, the systematic distribution of which divides the section into three well-defined subgroups. The sesquiterpene lactone profiles of the other two annual species of the genus, H. agrestis and H. porteri, exhibit significant differences relative to any species of sect. Helianthus, which supports their exclusion from the section.     

Phylogenetic relationships among New Caledonian Sapotaceae (Ericales): molecular evidence for generic polyphyly and repeated dispersal

The phylogeny of a representative group of genera and species from the Sapotaceae tribe Chrysophylleae, mainly from Australia and New Caledonia, was studied by jackknife analyses of sequences of nuclear ribosomal DNA. The phylogeny conflicts with current opinions on generic delimitation in Sapotaceae. Pouteria and Niemeyera, as presently circumscribed, are both shown to be nonmonophyletic. In contrast, all species currently assigned to these and other segregate genera confined to Australia, New Caledonia, or neighboring islands, form a supported clade. Earlier classifications in which more genera are recognized may better reflect relationships among New Caledonian taxa. Hence, there is need for a revision of generic boundaries in Chrysophylleae, and particularly within the Pouteria complex, including Leptostylis, Niemeyera, Pichonia, Pouteria pro parte (the main part of section Oligotheca), and Pycnandra. Section Oligotheca have been recognized as the separate genus Planchonella, a monophyletic group that needs to be resurrected. Three clades with strong support in our jackknife analysis have one Australian species that is sister to a relatively large group of New Caledonian endemics, suggesting multiple dispersal events between this small and isolated tropical island and Australia. The phylogeny also suggests an interesting case of a relatively recent and rapid radiation of several lineages of Sapotaceae within New Caledonia.     

Phylogenetic relationships within Pyrenodesmia sensu lato and the role of pigments in its taxonomic interpretation

Most lichens of the family Teloschistaceae (Ascomycota) produce yellow-orange-red anthraquinone pigments. However, the genus Pyrenodesmia encompasses species in which anthraquinones are absent and replaced by a gray pigment Sedifolia-gray. It was shown recently that these species are related to taxa with both anthraquinones and Sedifolia-gray (Caloplaca xerica group, C. haematites group, and C. cretensis) and to species with a brown pigment instead of both anthraquinones and Sedifolia-gray (C. demissa, C. obscurella, and C. reptans). Nevertheless, relationships between mentioned anthraquinone-containing and anthraquinone-lacking species remained unclear. In total, 8 DNA loci from 41 species were used here to resolve these uncertainties. We concluded that C. demissa, C. obscurella, and C. reptans are rather distant from the core of Pyrenodesmia, and we place them outside of Pyrenodesmia sensu lato. Within Pyrenodesmia sensu lato, three lineages were revealed and recognized on a generic level: the genus Pyrenodesmia sensu stricto (21 species), the genus Kuettlingeria (14 species), which is resurrected here, and the genus Sanguineodiscus (4 species), which is newly described here. The genus Pyrenodesmia includes taxa that never contain anthraquinones, but Sedifolia-gray. It matches with the former C. variabilis group. Taxa of the genera Kuettlingeria and Sanguineodiscus have anthraquinones in their apothecia and Sedifolia-gray in their thalli. The genus Kuettlingeria includes the former C. xerica group plus C. cretensis and C. diphyodes. The genus Sanguineodiscus includes the former C. haematites group and C. bicolor. The identity of Kuettlingeria (Caloplaca) diphyodes was clarified and the name Pyrenodesmia helygeoides was resurrected. Twenty-four new combinations were proposed.     

Diversity and distribution of saprobic microfungi in leaf litter of an Australian tropical rainforest

The diversity and distribution of microfungal assemblages in leaf litter of a tropical Australian forest was assessed using two methods: (1) cultures were isolated using a particle filtration protocol (wet season 2001), and (2) fruit bodies were observed directly on leaf surfaces following incubation in humid chambers (wet and dry season of 2002). Four tree species were studied using both methods, namely Cryptocarya mackinnoniana (Lauraceae), Elaeocarpus angustifolius (Elaeocarpaceae), Ficus pleurocarpa (Moraceae), and Opisthiolepis heterophylla (Proteaceae). An additional two species, Darlingia ferruginea (Proteaceae) and Ficus destruens (Moraceae), were studied using direct observations. In total, fruiting bodies of 185 microfungal species were recorded on leaf surfaces (31–81 species per tree species), and 419 morphotypes were detected among isolates obtained by particle filtration (111–203 morphotypes per tree species). Although the observed microfungal diversity was higher with the particle filtration protocol, both methods concurred with respect to microfungal distributions. The overlap of microfungal species in pair wise comparisons of tree species was low (14–30 %), and only 2 and 3 % of microfungal species were observed in leaves of all tree species by particle filtration and by direct observations respectively. Multivariate analysis of data from direct observations confirmed the hypothesis that microfungal assemblages are strongly influenced by host phylogeny and are also affected by seasonal and site factors. The importance of host species in shaping microfungal distributions was also supported by the particle filtration data. Several taxa new to science, as well as some widespread saprotrophs, were detected on only one host. The underlying reasons for this affinity remain unclear, but we hypothesise that a number of factors may be involved such as fungal adaptation to plant secondary metabolites or the presence of a biotrophic phase in the fungus' life cycle.     

Phytoserological systematic survey of the caprifoliaceae

Although several investigators have presented data suggesting that the Caprifoliaceae is polyphyletic in origin, the family has been retained as a taxon in recent classifications. Serological analyses of the taxa included within the family have been undertaken to provide additional taxonomic data. Precipitin techniques of double diffusion (Ouchterlony) and nephelometry (Boyden Procedure) were used to analyse serological similarities of seed proteins from representatives of the family. Three distinct groupings were detected for the taxa included in the Caprifoliaceae. AlthoughViburnum exhibited greatest serological similarity withSambucus, Viburnum was quite distinct from all members of the family investigated.Sambucus also was somewhat distinct from the other genera and exhibited about as much serological correspondence withCornus of the Cornaceae as with any tested member of the Caprifoliaceae. The remaining species examined formed a very close serological grouping. These data can be interpreted as supporting either a monophyletic or polyphyletic origin of the family as presently composed, because of the different arrangements of the families Caprifoliaceae and Cornaceae in the various systems of classification.     

Plastome phylogenomic insights into the Sino‐Japanese biogeography of Diabelia (Caprifoliaceae)

Understanding the causes of the Sino‐Japanese disjunctions in plant taxa has been a central question in eastern Asian biogeography, with vicariance or long‐distance dispersal often invoked to explain such patterns. Diabelia Landrein (Caprifoliaceae; Linnaeoideae) comprises four shrubby species with a Sino‐Japanese disjunct distribution. The species diversification time within Diabelia, covering a long geological history of the formation process of the Sino‐Japanese flora, dated back to the middle Oligocene, therefore, Diabelia would be an ideal model to elucidate the biogeographic patterns of Sino‐Japanese disjunctions with climate fluctuation. In this study, we analyzed complete plastome sequence data for 28 individuals representing all four species of Diabelia. These 28 plastomes were found to be highly similar in overall size (156 243–157 578 bp), structure, gene order, and content. Our phylogenomic analysis of the plastomes supported a close relationship between Diabelia ionostachya (Nakai) Landrein & R.L. Barrett var. wenzhouensis (S.L. Zhou ex Landrein) Landrein from eastern China and Diabelia spathulata (Siebold & Zucc.) Landrein var. spathulata from Japan. Diabelia serrata (Siebold & Zucc.) Landrein was identified as sister to a population of Diabelia sanguinea (Makino) Landrein from Tochigi in central Japan and D. spathulata Landrein, from Toyama, central Japan. Most Diabelia lineages were estimated to have differentiated 8–28 Mya. Our results indicate that two independent vicariance events could explain the disjunction between Japan and Korea in the mid to late Miocene, and between Zhejiang and Japan in the early Miocene.     

Two-dimensional gel electrophoresis as a taxonomic tool: Evidence from the centrospermae

Two-dimensional polyacrylamide gel (2-D PAGE) electrophoresis was appraised as an experimental technique for assessing systematic relationships among higher plants and to determine at which level in the taxonomic hierarchy this technique is most generally applicable. 2-D PAGE was performed on denatured extracts of mature leaves from 25 species representing five families of the order Centrospermae (Caryophyllales, Chenopodiales) in the Angiospermae as well as Welwitschia mirabilis (Gymnospermae). Cluster analysis of a 256 spot binary-coded data set derived from the computer-encoded spot patterns of the 25 species successfully separated taxa from the individual to the familial levels of the taxonomic hierarchy in accordance with traditional taxonomic delineations of the taxa.     

A systematic study of North American Angelica species (Apiaceae) based on nrDNA ITS and cpDNA sequences and fruit morphology

Angelica is a taxonomically complex genus widespread throughout the North Temperate Zone. Previous phylogenetic studies of the genus have focused primarily on its East Asian species. The relationships among its North American members, the monophyly of these species, and the value of fruit morphology in circumscribing its taxa have yet to be examined. This study represents the most comprehensive sampling of Angelica to date (100 species) and includes all 26 species in North America. Relationships are inferred using Bayesian inference, maximum likelihood, and maximum parsimony analyses of ITS sequences and, for multiple accessions of each North American species, cpDNA ndhF-rpl32, rpl32-trnL, and psbM-psbD sequences. The fruit morphological characters examined were those considered phylogenetically important in East Asian Angelica. The results revealed that the North American species fell into three major clades: North American Angelica clade, Archangelica clade, and the Eurasian Angelica clade. Angelica dawsonii has affinities with Lomatium brandegeei. Fourteen species within the North American Angelica clade were strongly supported as monophyletic. Two paraphyletic species resulted in new combinations in A. lineariloba and A. venenosa. Conflict between the ITS-derived and cpDNA-derived phylogenies and the lack of resolution in portions of the trees may be due to chloroplast capture and rapid species radiation. Fruit morphology supported some interspecific relationships based on molecular data, and relationships revealed by ITS and cpDNA data were roughly in accordance with fruit classification type and geographic distribution region, respectively. A diagnostic key based on fruit morphology is provided for the identification of the North American Angelica taxa.     

中国热带粒毛盘菌属的物种多样性研究

本文在对我国盘菌资源调查的基础上,分析研究了热带地区粒毛盘菌属真菌的物种多样性。本研究共分析451份标本,属于35个分类单位,其中Lachnum abnorme var. abnorme, L. brasiliense, L. flavidulum, L. pteridophyllum, L. sclerotii和L. virgineum 6个种的个体数量均在总数的6 %以上,占已观察标本总数的73.4 %,是我国热带地区的常见种。物种多样性分析表明,海南的物种丰富度（S=22）和多样性指数（H′=2.6696）最高,云南与广西的物种丰富度相似。采用群落系数（coefficient of community,cc）比较了不同地区的物种分布相似性。本文还试图探讨物种分布与海拔高度、生境、基物间的关系。粒毛盘菌属真菌在海拔60～2700 m的地带均有分布,由于调查和取样的局限性,物种随海拔高度变化的规律不明显;地理分布上大致可分为世界性分布、间断性分布和地方特有三种分布型。     

Genetic differences between two allopatric sibling species of the genus Polydora (Polychaeta: Spionidae) from the West Pacific

Polydora vulgaris Mohammad, 1972, a commensal borer of the oysters Pinctada margaritifera and Hyotissa hyotis from the South China Sea, was investigated by means of starch gel electrophoresis. Polydora vulgaris and the allopatric sibling Polydora glycymerica Radashevsky, 1993, a commensal borer of the bivalve Glycymeris yessoensis from the Sea of Japan, were compared with respect to their allozymic variation and number of isozyme loci. Interspecific differences in the number of gene loci coding for three enzymes: alanopine dehydrogenase, glucose-6-phosphate isomerase and -iditol dehydrogenase were revealed suggesting that we are dealing with two valid species. Two different modes of origin duplicate loci in polydorids are dicussed—polyploidization and regional gene duplication. The use of gene number as a character for discriminating between morphologically indistinguishable allopatric polydorid taxa is outlined.