Evolution of ommatidium structure in the Trogidae (Coleoptera)

Abstract. Ommatidium lens structure in the Trogidae and the monotypic Glaresidae is studied. Three types (eucone, duocone and exocone) are found in the Trogidae [and most Scarabaeoidea]; only the eucone type occurs in the Glaresidae. Evidence is presented that evolution of ommatidium type in the Trogidae has proceeded from a basic eucone type such as that in extant Glaresis and Trox , to a more derived eucone as in Polynoncus and some species of the Omorgus subgenera Omorgus and Afromorgus , through various states of the duocone type as in the remainder of the species belonging to these subgenera, to the highly evolved exocone ommatidium found in the monobasic Omorgus (Haroldomorgus). An improvement in optics of the duocone and exocone over the eucone may have driven the evolution of these types. Ommatidium structure does little to confirm or refute proposed relationships among trogid taxa but does clearly indicate the path of evolution of the different lens systems in the Trogidae and illustrates the probable course of evolution of ommatidium structure in the Scarabaeoidea.     

Phylogeny of the family Trogidae (Coleoptera: Scarabaeoidea) inferred from mitochondrial and nuclear ribosomal DNA sequence data

Trogidae constitute a monophyletic and biologically unique family within Scarabaeoidea, being the only keratinophagous group in the superfamily. Traditionally, the family has been divided into three distinctive genera, Polynoncus Burmeister, Omorgus Erichson and Trox Fabricius. Although the taxonomy of the group is relatively well studied, changes to the existing classification have recently been proposed and the family as currently constituted has not been subjected to phylogenetic analyses. Here we present a molecular phylogeny for this cosmopolitan family based on three partially sequenced gene regions: 16S rRNA, 18S rRNA and 28S rRNA (domain 2). Included in the analyses are representatives belonging to four of the five extant genera (and three of the four subgenera) from all major zoogeographic regions, representing about 20% of the known trogid species diversity in the family. Phylogenetic analyses performed included parsimony and Bayesian inference. We deduce their historical biogeography by using trogid fossils as calibration points for divergence estimates. Our analyses resolved relationships between and within genera and subgenera that are largely congruent with existing phylogeny hypotheses based on morphological data. We recovered four well‐supported radiations: Polynoncus, Omorgus, Holarctic Trox and African Phoberus MacLeay. On the basis of this study, it is proposed that taxonomic changes to the generic classification of the family be made. The subgenera Trox and Phoberus should be elevated to genera to include the Holarctic and all the Afrotropical species, respectively, and Afromorgus returned to subgeneric rank. Estimates of divergence time are consistent with a Pangaean origin of the family in the Early Jurassic. The subsequent diversification of the major lineages is largely attributed to the break‐up of Pangaea and Gondwana in the Middle Jurassic and early Late Cretaceous, respectively.     

Molecular phylogenetics of Acacia (Fabaceae: Mimosoideae) based on the chloroplast MATK coding sequence and flanking TRNK intron spacer regions

The tribe Acacieae (Fabaceae: Mimosoideae) contains two genera, the monotypic African Faidherbia and the pantropical Acacia, which comprise about 1200 species with over 950 confined to Australia. As currently recognized, the genus Acacia is subdivided into three subgenera: subg. Acacia, subg. Aculeiferum, and the predominantly Australian subg. Phyllodineae. Morphological studies have suggested the tribe Acacieae and genus Acacia are artificial and have a close affinity to the tribe Ingeae. Based on available data there is no consensus on whether Acacia should be subdivided. Sequence analysis of the chloroplast trnK intron, including the matK coding region and flanking noncoding regions, indicate that neither the tribe Acacieae nor the genus Acacia are monophyletic. Two subgenera are monophyletic; section Filicinae of subgenus Aculeiferum does not group with taxa of the subgenus. Section Filicinae, eight Ingeae genera, and Faidherbia form a weakly supported paraphyletic grade with respect to subg. Phyllodineae. Acacia subg. Aculeiferum (s. s.) is sister to the grade. These data suggest that characters currently used to differentiate taxa at the tribal, generic, and subgeneric levels are polymorphic and homoplasious in cladistic analyses.     

Pollen Morphology of the Platycodonoid Group (Campanulaceae s. str.) and Its Systematic Implications

In this study, we examined the pollen morphology of the platycodonoid group in Campanulaceae s. str. using a scanning electronic microscope. We used pollen grains of 25 accessions representing 24 species of the Codonopsis complex (including Campanumoea, Cyclocodon, Leptocodon, and all three subgenera of Codonopsis), which is extremely controversial among authors for taxonomic treatment. Pollen morphology of all the other genera in the group observed by previous authors is taken into account in our discussion. A total of nine pollen types with two subtypes in the group were recognized and named for the first time. Molecular and morphological data imply that each pollen type corresponds to a natural group at generic level, and thus the mergence of Leptocodon with Codonopsis and the restoration of Cyclocodon as a separate genus are justifiable, and Codonopsis subg. Pseudocodonopsis, subg. Obconicicapsula, and two species of Codonopsis subg. Codonopsis (C. purpurea and C. chimiliensis) may be better classified as three independent genera separate from the core Codonopsis.     

Seed-coat anatomy in Fumariaceae-Fumarioideae

Seed-coat anatomy is described in 122 species of Fumarioideae, which represent all the genera, subgenera, and most sections. Nine seed-coat types were recognized: (I) Dicentra subg. Hedycapnos , (II) Dicentra subg. Chrysocapnos , (III) Dicentra subg. Macranthos , (IV) Dicentra subg. Dicentra , (V) Corydalis p.p. , (VI) rest of Corydaleae, Cysticapnos, Pseudofumaria and Ceratocapnos , (VII) Discocapnos and Sarcocapnos p. p. , (VIII) Sarcocapnos p. p., Platycapnos and Trigonocapnos , and (IX) Fumariinae. Variable characters are polarized based on the comparison with Fumariaceae Hypecooideae, Papaveraceae and Pteridophyllaceae. It is assumed that endotestal seed-coat type (I) is most primitive, that exotestal seed coat types (II—VIII) are derived therefrom, and that the reduction of the mechanical layer, including the origin of thin seed-coat type (IX) occurred repeatedly in combination with indehiscent, hard-walled fruits. Dicentra subg. Hedycapnos (with type I) possesses a combination of primitive testal characters unique within the subfamily, suggesting it represents a sister group to the rest of the subfamily. Each of the other subgenera (with II, III or IV) is also characterized by a unique combination of seed-coat characters, which are found in the outgroups but not in the other genera. Seed-coat characters support the monophyly of Fumarioideae exclusive of Dicentra subg. Hedycapnos , Fumarioideae exclusive of Dicentra , of Dicentra subg. Dicentra , of Corydalis p.p. , and of Fumariinae.     

MORPHOLOGY,EVOLUTION, AND TAXONOMIC SIGNIFICANCE OF THE INFLORESCENCE IN CORDYLANTHUS (SCROPHULARIACEAE)

The genus Cordyhmthus has considerable diversity in its inflorescences while the other genera of tribe Rhinantheae (Scrophulariaceae) uniformly have racemes or spikes. Four distinct inflorescence types are recognized and their homologies and evolutionary history are postulated. Thus it is suggested that the basic florescence type, the elongated spike (Type I), has undergone evolutionary reduction to a few-flowered spike and ultimately to a single-flowered florescence (Type II). Further evolution involving processes of compaction and clustering of the single-flowered florescences has resulted in glomerulate clusters (Type III) and spiciform clusters (Type IV). Knowledge of inflorescence homologies and distribution of the four inflorescence types in the genus has been of considerable aid in formulating a new infrageneric classification. Using evidence primarily from inflorescence, floral, and seed morphology, as well as from geographical distribution and ecology, a classification is proposed establishing three subgenera, namely subg. Dicranostegia, subg. Hemistegia, and subg. Cordylanthus, the last with three sections, sect. Cordylanthus, sect. Anisocheila, and sect. Ramosi.     

A taxonomic revision of Labiostrongylus (Labiostrongylus) (Yorke & Maplestone, 1926) and Labiostrongylus (Labiomultiplex) n. subg. (Nematoda: Cloacinidae) from macropodid and potoroid marsupials

The morphological characters used to differentiate species in the genus Labiostrongylus Yorke & Maplestone, 1926, parasitic in macropodid and potoroid marsupials, are discussed. The genus is divided into three subgenera Labiostrongylus (Labiostrongylus), L. (Labiomultiplex) n. subg. and L. (Labiosimplex) n. subg. on the basis of the presence or absence of interlabia and the morphology of the oesophagus. A key to the subgenera is given and a detailed revision of two of the subgenera is presented. Keys to each of the subgenera are given, the species discussed being: L. (L.) labiostrongylus) (type-species) (syn. L. (L.) insularis, L. (L.) grandis, L. (L.) macropodis sp. inq. and L. (L.) nabarlekensis n. sp., in the subgenus Labiostrongylus, and L. (Lm.) eugenii, L. (Lm.) novaeguineae, L. (Lm.) onychogale, L. (Lm.) uncinatus, L. (Lm.) billardierii n. sp., L. (Lm.) constrictis n. sp., L. (Lm.) kimberleyensis n. sp., L. (Lm.) thylogale n. sp., and L. (Lm.) potoroi, n. sp., in the subgenus Labiomultiplex.     

A Contribution to the Taxonomy of the Genus Xiphinema Cobb, 1913

In a comparative study of different populations of Xiphinema, the significance of the female gonad structure in species determination is stressed, and monodelphic, pseudomonodelphic, and didelphic forms in the genus are defined. X. chambersi is redescribed and illustrated, X. ensiculiferum and X. krugi are redefined, and X. ensiculiferoides n.sp. and X. orthotenum n.sp. are described. Proposed new synonymies are: X. itanhaense = X. brasiliense; X. bulgariensis and X. conurum = X. italiae; X. ifacolum = X. basiri; X. macrostylum = X. ensiculiferum; X. truncatum = X. elongatum; and X. vulgare = X. setariae. X. yapoense is considered species inquirenda and X. obtusum a nomen dubium. The following eight subgenera of the genus Xiphinema are proposed: Radiphinema n. subg., Krugiphinema n. subg., Xiphinema n. subg., Elongiphinema n. subg., Halliphinema n. subg., Basiphinema n. subg., Rotundiphinema n. subg., and Diversiphinema n. subg. A key to the subgenera of Xiphinema is presented, plus a list of 50 species in the genus, their synonyms, and 10 species inquirendae.     

A description of the larva and pupa of Trox mandli (Coleoptera, Trogidae) from the Russian Far East

The previously unknown larvae of Trox mandli Balthasar of the family Trogidae are described and illustrated. The larva of T. mandli Balthasar differs from that of T. sabulosus (Linnaeus) in shape of the setae on abdominal tergite I, and from that of T. scaber (Linnaeus), in the chaetotaxy of the epipharynx. A key to the known larvae of the genus Trox Fabricius from the Russian Far East is given.     

Phylogenetic relationships of Salvia (Lamiaceae) in China: Evidence from DNA sequence datasets

With 84 native species, China is a center of distribution of the genus Salvia (Lamiaceae). These species are mainly distributed in Yunnan and Sichuan provinces (southwestern China), notably the Hengduan Mountain region. Traditionally, the Chinese Salvia has been classified into four subgenera, Salvia, Sclarea, Jungia, and Allagospadonopsis. We tested this classification using molecular phylogenetic analysis of 43 species of Salvia from China, six from Japan, and four introduced species. The nuclear ribosomal internal transcribed spacer region and three chloroplast regions (rbcL, matK, and trnH-psbA) were analyzed by maximum parsimony, maximum likelihood, and Bayesian methods. Our results showed that the Chinese (except Salvia deserta) and Japanese Salvia species formed a well-supported clade; S. deserta from Xinjiang grouped with Salvia officinalis of Europe. In addition, all introduced Salvia species in China were relatively distantly related to the native Chinese Salvia. Our results differed from the subgeneric and section classifications in Flora Reipublicae Popularis Sinicae. We suggested that sections Eusphace and Pleiphace should be united in a new subgenus and that sect. Notiosphace should be removed from subg. Sclarea and form a new subgenus. Our data could not distinguish a boundary between subg. Allagospadonopsis and sect. Drymosphace (subg. Sclarea); the latter should be reduced into the former. Further clarification of the phylogenetic relationships within Salvia and between Salvia and related genera will require broader taxonomic sampling and more molecular markers.     

Morphological variation in pollen grains of <Emphasis Type="Italic">Mucuna</Emphasis> (Leguminosae): new biogeographic and evolutionary patterns

Mucuna comprises 105 species with an overall pantropical distribution and is divided into three subgenera: M. subg. Mucuna, M. subg. Stizolobium and M. subg. Macrocarpa. Although phylogenetic studies have supported the occurrence of three main clades, evolutionary relationships among them are not fully resolved. The objective of this study was to examine pollen grain morphology from representatives of all three subgenera and map these onto the phylogenetic trees generated by analysis of other characters. Pollen grain surface, form, size, and aperture number were compared. A Bayesian inference tree using matK sequences was constructed. The results indicate that the representatives of M. subg. Macrocarpa have the smallest pollen grains in the genus (a synapomorphic character here identified for this subgenus) and that species of subgenus Mucuna (those with umbelliform inflorescences) have the largest pollen grains. Additional morphological diversity of the pollen grain surface was noted: reticulate and/or micro-reticulate (in all three subgenera), perforate, gemmate or verrucose (only in M. subg. Mucuna). For all studied taxa, the pollen grains are triaperturate, except for two species of M. subg. Mucuna, which have tetraperturate pollen. The phylogenetic tree obtained using the matK marker resolved M. subg. Stizolobium as the earliest diverging lineage in Mucuna. Based on this phylogeny, a reticulate ornamentation pattern of the pollen surface may represent the ancestral state for the genus, while the larger pollen size and the foraminate, gemmate, and verrucose ornamentations are derived characteristics within the genus. These putative derived ornamentations have been observed only in neotropical species.     

A revision of the moss genus Trachyphyllum Gepp (Thuidiaceae)

Trachyphyllum is transferred from the Entodontaceae to the Thuidiaceae on the basis of correlated gametophytic and sporophytic characters. The genus is considered to consist of two subgenera: subg.Trachyphyllum forT. inflexum (with numerous new synonyms),T. gastrodes, T. dusenii andT. borgenii; and subg.Carinatum, subg. nov., forT. carinatum,T. jeyporense andT. touwianum, n. sp. All the species are keyed, described and illustrated.     

Discontinuous gas exchange and water loss in the keratin beetle Omorgus radula: further evidence against the water conservation hypothesis?

Discontinuous gas exchange cycles are demonstrated in Omorgus radula (Erichson) (Coleoptera, Trogidae) for the first time, thus extending evidence for such cycles to another family of beetles. The closed, flutter and open phases of the cycle were clearly distinguishable in this species, and the duration of these phases was 221 ± 28, 1403 ± 148 and 755 ± 43 s (mean ± SE), respectively. No evidence for significant intraspecific mass scaling of VCO₂ or any of the components of the cycle was found. Although the prolonged F‐phase recorded here is unusual for many insects, it has previously been found in other scarabaeoid beetles, especially those from xeric environments. It has been suggested that such modulation of the discontinuous gas exchange cycle may result in a reduced VCO₂ and, consequently, reduced water loss. In O. radula VCO₂ (15.25 ± 1.49 μl/h) was considerably lower than that predicted from its body mass (0.207 ± 0.006 g). However, the small relative contribution of respiratory transpiration (6.5%) to total water loss indicated that reduced VCO₂ has little to do with water economy. Rather, it may be a consequence of generally low activity levels of these beetles. The low respiratory water loss, but distinct subterranean component in the adult life of O. radula, lend some credence to the hypothesis suggesting that regular use of subterranean habitats might have been responsible for the evolution of discontinuous gas exchange cycles. However, non‐adaptive hypotheses can still not be discounted.     

Rhizome structure and evolution in the ant-associated epiphytic fern Lecanopteris Reinw. (Polypodiaceae)

GAY, H., 1993. Rhizome structure and evolution in the ant-associated epiphytic fern Lecanopteris Reinw. (Polypodiaceae). The Lecanopteris rhizome is expanded or hollow, and is used as a nest by ants of the genera Iridomyrmex and Crematogaster. The 13 species of Lecanopteris display six rhizome forms, unequally distributed between two subgenera. Subgenus Myrmecopteris comprises four species, each possessing a characteristic rhizome: L. mirabilis has a solid, arched rhizome, with the domatium between the rhizome underside and host trunk; L. sarcopus displays dimorphism between solid frond-bearing axes and hollow, frondless side branches; the rhizome of L. Crustacea is hollow but phyllopodia are solid; L. sinuosa has hollow rhizomes and phyllopodia. The architecture of L. mirabilis, L. sarcopus and L. Crustacea results in a compact, many-layered domatium, but L. sinuosa has a tittle-branched habit. Members of subg. Lecanopteris are completely hollow and have a compact architecture: six species typified by L. pumila have a central gallery and hollow phyllopodia, and three species typified by L. darnaedii have two gallery and chamber systems. The genus Lecanopteris is unlikely to be monophyletic; its nearest relative is Phymalodes. Phylogeny in subg. Myrmecopteris is unclear; no gradation of rhizome complexity exists. In subg. Lecanopteris, L. curtisii is considered most similar to the ancestral species, giving rise to the L. pumila group, which engendered the L. darnaedii group.     

Holocentric chromosome behaviour inCuscuta (Cuscutaceae)

The present study demonstrates thatCuscuta babylonica Choisy has holocentric chromosomes. Evidence for this phenomenon comes from three different observations. (1) Mitosis: During metaphase and anaphase the sister-chromatids are situated parallel to the equatorial plane with no sign of localized kinetochore activity. (2) Inverted meiosis in microsporocytes. (3) X-rayed microsporocytes, in which the numerous chromosome fragments do not show any lagging or formation of micronuclei. We assume that only one out of the three subgenera inCuscuta, namely subg.Cuscuta, has holocentric chromosomes, while the two other subgenera have monocentric chromosomes.     

Phylogeny and Evolution in Cariceae (Cyperaceae): Current Knowledge and Future Directions

The goal of this study was to review the impact of DNA sequence analyses on our understanding of Cariceae phylogeny, classification and evolution. To explore character evolution, 105 taxa from four different studies were included in an nrDNA ITS + ETS 1f analysis of all recognized genera (Carex, Cymophyllus, Kobresia, Schoenoxiphium, Uncinia) and Carex subgenera (Carex, Psyllophora, Vignea, Vigneastra). As in previous analyses, four major Cariceae clades were recovered: (1) a “Core Carex Clade” (subg. Carex, Vigneastra, Psyllophora p.p); (2) A “Vignea Clade” (subg. Vignea, Psyllophora p.p.); (3) a “Schoenoxiphium Clade” (Schoenoxiphium, subg. Psyllophora p.p.), and (4) a “Core Unispicate Clade” (Uncinia, Kobresia, subg. Psyllophora p.p.). All studies provide strong support (86–100% BS) for the Core Carex and Vignea Clades, but only weak to moderate support (<50%–78% BS) for the Core Unispicate and Schoenoxiphium Clades. The relationships of these groups are unresolved. Studies suggest that Carex is either paraphyletic with respect to all Cariceae genera or to all genera except Schoenoxiphium. Kobresia is a grade, but Uncinia and possibly Schoenoxiphium are monophyletic. The monotypic Cymophyllus is indistinct from Carex subg. Psyllophora species. Character analyses indicate that inflorescence proliferation and reduction have occurred in all major clades, and that the Cariceae’s unisexual flowers have evolved from perfect flowers. The ancestor to Cariceae possessed a multispicate inflorescence with cladoprophylls and female spikelets with tristigmatic gynoecia and closed utricles. This morphology is most similar to extant Carex subg. Carex species, which contradicts the nearly unanimous assumption that the highly compound inflorescences of Schoenoxiphium are primitive. Since taxonomic sampling and statistical support for phylogenies have generally been poor, we advocate the temporary maintenance of the four traditional Carex subgenera with androgynous unispicate species placed within subg. Psyllophora and dioecious and gynaecandrous unispicate species distributed amongst subgenera Carex and Vignea. A collective effort focused on developing new nuclear markers, on increasing taxonomic and geographic sampling, and on studying development within the context of phylogeny, is needed to develop a phylogenetic classification of Cariceae.     

山茱萸科花粉形态研究

本文应用光学显微镜与扫描电子显微镜观察了山茱萸科Cornaceae4属(按照Wangerin1910年的概念)27种花粉形态,结果如下: 1.根据花粉特征,支持把青荚叶属Helwingia,桃叶珊瑚属Aucuba,鞘柄木属Torricellia三属分别独立成科的观点。 2.梾木属Cornus可明显区分为两种类型,即梾木型和四照花型;梾木型还可再分为三个亚类型.即灯台树亚型,长圆叶梾木亚型和梾木亚型。 5.支持四照花属应从梾木属中分出而独立成属;而在四照花属Dendronbenhamia下设立北美四照花亚属Subg. Apocarpea和四照花亚属Subg. Syncarpea;在梾木属下设立梾木亚属Subg. kraniopsis, 灯台树亚属Subg.Masomora等亚属的观点。 4.建立了—新亚属——长圆叶梾木亚属。     

Molecular phylogenetics of Fouquieriaceae: evidence from nuclear rDNA ITS studies

Molecular sequence data from the 18S-26S rDNA internal transcribed spacer (ITS) region support the monophyly of Fouquieria sensu lato (Fouquieriaceae) and the three subgenera (subg. Fouquieria, subg. Bronnia, subg. Idria) previously recognized within it. Resolution within subg. Fouquieria differs somewhat between parsimony and maximum likelihood (ML) trees. Section Fouquieria and sect. Ocotilla within subg. Fouquieria are not well supported as monophyletic groups. Uncertainty regarding placement of the root within Fouquieriaceae makes discussion of character evolution within the family difficult. Three root positions are consistent with rate-constant evolution of ITS sequences: (1) along the branch to subg. Idria, (2) along the branch to subg. Bronnia, and (3) along the branch to subg. Fouquieria. The first root position listed is equivalent to an outgroup rooting. The third root position listed is equivalent to a midpoint rooting. Of the three root positions above, only the third is along a branch that may be sufficiently long to act as a long-branch attractor. The first two root positions would result in character reconstruction suggesting that succulent growth forms and white floral pigmentation are ancestral within the family, with shifts to woody growth forms and to red floral pigmentation. The third root position results in equivocal reconstruction of the ancestral growth form, equivocal reconstruction of ancestral floral pigmentation in parsimony trees, and a suggestion of white floral pigmentation as ancestral in ML trees. Two previous hypotheses of polyploid origins are compatible with the molecular data presented here: (1) origin of the tetraploid F. diguetii from F. macdougalii, and (2) allopolyploid origin of the hexaploid F. burragei from the tetraploid F. diguetii and a diploid species similar to F. splendens. Direct descent of the hexaploid F. columnaris from the subg. Bronnia lineage is not supported by our data. An amphiploid origin of F. columnaris involving a member of the subg. Bronnia lineage and an extinct taxon outside subg. Bronnia, however, cannot be ruled out.     

Addressing the "hardest puzzle in American pomology:" Phylogeny of Prunus sect. Prunocerasus (Rosaceae) based on seven noncoding chloroplast DNA regions

Prunus subg. Prunus sect. Prunocerasus (Rosaceae) is a North American taxon with 17 commonly recognized taxa. To test the hypothesis of monophyly for the section we sequenced the trnG and rpL16 introns and the trnH-psbA and trnS-trnG intergenic spacers for at least two representatives of each of the five subgenera in Prunus. Additionally we sampled heavily among Prunus subg. Prunus sections Prunus and Armeniaca and Prunus subg. Amygdalus because these groups are putatively most closely related to Prunocerasus. Once monophyly of sect. Prunocerasus was shown we added the sequences of trnL and rpS16 introns and the trnL-trnF spacer in an attempt to increase resolution within the section. The species of sect. Prunocerasus showed an initial split with P. subcordata, the only species from western North America, sister to the rest of the group. The remaining species fell into three primary clades. Within each of the three primary clades there was little phylogenetic resolution. Lastly, we present evidence that P. texana, previously classified in subg. Amygdalus, may be a plum or at least contain a Prunocerasus chloroplast. This is the first phylogenetic hypothesis presented for sect. Prunocerasus, and the clades recovered contrast sharply with previously defined groups based on morphological characters.