Taxonomic Sections Research Articles

Designing food and habitat trees for urban koalas: graft compatibility, survival and height of tall eucalypt species grafted onto shorter rootstocks

The Corymbia and Eucalyptus species eaten by koalas are generally large trees, but these are often unpopular with urban landowners and councils because of the dangers of limbs falling from a great height. We aimed to develop shorter koala food and habitat trees for urban areas by heterografting tall eucalypt species onto rootstocks of shorter species and comparing their survival and growth with homografted trees and control ungrafted trees. In total, 12 of 14 interspecific scion/rootstock combinations were grafted successfully in the nursery but graft compatibility and field survival depended on taxonomic relatedness. The six interspecific combinations that had multiple surviving trees at 5 years after planting were all between species within the same taxonomic section or between a species and its own interspecific hybrid. Almost all trees died from grafts between species in different taxonomic sections. In most cases, the height of surviving interspecific grafted trees did not differ from control intraspecific grafted trees or from ungrafted trees of their scion species. Grafting elicited a ‘thrive or not survive’ response that diminished its usefulness for producing shorter trees. However, one combination, E. moluccana/E. behriana, had field survival of 40% and reduced height (4.0 m vs 9.9 m). These could be valuable habitat trees for koalas and other fauna in urban areas.

Status of <i>Reseda pentagyna</i> Abdallah & A.G. Miller (Resedaceae) inferred from combined nuclear ribosomal and chloroplast sequence data

The present study focuses on the status of Reseda pentagyna Abdallah & A.G. Miller (Resedaceae). The internal transcribed spacer (ITS) region of nuclear ribosomal DNA and chloroplast trnL-F gene of the questioned species were sequenced. The Basic Local Alignment Search Tool (BLAST) search showed maximum identity with R. stenostachya. The parsimony analysis of ITS, trnL-F and combined sequences data analyses revealed grouping of Reseda species consistent with established taxonomic sections of the genus, R. pentagyna showed proximity with R. stenostachya (100% bootstrap support), nested within the clade of section Reseda.DOI: http://dx.doi.org/10.3329/bjpt.v20i2.17397Bangladesh J. Plant Taxon. 20(2): 233-238, 2013

The Phylogeny and Biogeographic History of Ashes (Fraxinus, Oleaceae) Highlight the Roles of Migration and Vicariance in the Diversification of Temperate Trees

The cosmopolitan genus Fraxinus, which comprises about 40 species of temperate trees and shrubs occupying various habitats in the Northern Hemisphere, represents a useful model to study speciation in long-lived angiosperms. We used nuclear external transcribed spacers (nETS), phantastica gene sequences, and two chloroplast loci (trnH-psbA and rpl32-trnL) in combination with previously published and newly obtained nITS sequences to produce a time-calibrated multi-locus phylogeny of the genus. We then inferred the biogeographic history and evolution of floral morphology. An early dispersal event could be inferred from North America to Asia during the Oligocene, leading to the diversification of the section Melioides sensus lato. Another intercontinental dispersal originating from the Eurasian section of Fraxinus could be dated from the Miocene and resulted in the speciation of F. nigra in North America. In addition, vicariance was inferred to account for the distribution of the other Old World species (sections Sciadanthus, Fraxinus and Ornus). Geographic speciation likely involving dispersal and vicariance could also be inferred from the phylogenetic grouping of geographically close taxa. Molecular dating suggested that the initial divergence of the taxonomical sections occurred during the middle and late Eocene and Oligocene periods, whereas diversification within sections occurred mostly during the late Oligocene and Miocene, which is consistent with the climate warming and accompanying large distributional changes observed during these periods. These various results underline the importance of dispersal and vicariance in promoting geographic speciation and diversification in Fraxinus. Similarities in life history, reproductive and demographic attributes as well as geographical distribution patterns suggest that many other temperate trees should exhibit similar speciation patterns. On the other hand, the observed parallel evolution and reversions in floral morphology would imply a major influence of environmental pressure. The phylogeny obtained and its biogeographical implications should facilitate future studies on the evolution of complex adaptive characters, such as habitat preference, and their possible roles in promoting divergent evolution in trees.

Pollination of slipper orchids (cypripedioideae): a review

Cypripedioideae (five genera; ca. 176 species) are widespread in temperate and tropical Asia and America. About a quarter (42) of the species have been studied to determine their pollinators and/or breeding systems. All flowers are one-way traps pollinated by insects of particular types and size. Slipper orchids are selfcompatible and pollinated by deceit. Most Cypripedium species are pollinated by bees, whereas some smallerflowered species are pollinated by flies, and a few are pollinated by both. Most bee-pollinated Cypripedium species appear to be generalized food mimics. The fly-pollinated species have evolved diverse pollination systems that utilize a variety of flies as pollen vectors, including fruit flies, dung flies, and a fungal spore-eating hoverfly (Syrphidae). Most species of the tropical Asian Paphiopedilum and tropical American Phragmipedium are pollinated by hoverflies; flowers of many species in both genera have aphid-like spots that attract gravid female hoverflies that normally lay their eggs in aphid colonies. The more brightly colored Paphiopedilum micranthum and Phragmipedium besseae are pollinated by Hymenoptera. Autogamy is limited but occurs most frequently in Phragmipedium species. About two-thirds of the insect-pollinated slipper orchids (25/37) have evolved highly specialized flowers that are pollinated by a single pollinator or several pollinator species in the same genus. Species belonging to the same taxonomic section usually have the same pollination system. The deceit-pollination system of Cypripedioideae appears to have evolved early in diversification of Orchidaceae.

Phylogenetic relationship of wild and cultivated yam species (Dioscorea spp.) of India inferred from PCR–RFLP analysis of two cpDNA loci

The genus Dioscorea comprises approximately 600 species worldwide and about 50 in India. Dioscorea is economically very useful because of its food and medicinal value. Polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) analysis was employed to study interspecific relationship between four cultivated and thirteen wild species belonging to seven taxonomical sections found in India. Restriction digestion analysis was performed for the amplified products of chloroplast DNA (cpDNA) loci psbA–trnH and trnL-F regions. Out of 17 restriction endonucleases tested, 5 endonucleases had restriction sites in psbA–trnH region and 6 endonucleases had restriction sites in trnL-F region. Digestion of amplified products with these restriction endonucleases showed 70 fragments of which 62 fragments (88 %) were polymorphic. Dendrogram obtained from UPGMA cluster analysis of two combined loci shows D. bulbifera of section Opsophyton to be closely placed with species of sect. Enantiophyllum. High similarity values obtained in this study between D. pentaphylla (sect. Botrysicyos) and D. esculenta (sect. Combilium) support their common origin. The average of genetic similarities between the ten species of Enantiophyllum section was 82.3 % showing their closeness. The present study suggests that the less studied New World species, D. floribunda (sect. Heterostemon) could have evolved from old world section, Lasiophyton. The principal component analysis (PCA) obtained from data of the two loci shows D. deltoidea of sect. Stenophora to be an outgroup. Interspecific genetic similarities showed D. deltoidea with low similarity values ranging from 27.5 to 37.5 % compared with other species and was, therefore, the most divergent species. D. deltoidea of section Stenophora shows distinctness because of its primitive characters. This study, therefore, establishes species relationships between wild and cultivated yams of India which would help in yam crop improvement programmes.

Tri-trophic interactions among congeneric sympatric host plants of Chamaecrista, seed predators and parasitoids

The defensive role against seed predation of a set of plant traits in 13 congeneric sympatric taxa (Chamaecrista: Leguminosae), and the influence of the third trophic level on seed predators’ performance and host range were investigated. Taxa co-occur in rupestrian grasslands in Serra do Cipo, Brazil, and belong to three taxonomic sections. Fruit production, fruit pubescence, and seed size were analyzed. Measures of these traits in the 13 taxa were regressed separately against seed predation rates by endophagous and ectophagous insects. Time of seed production and fruit pubescence showed no influence on seed predation rates by either predator type. Seed size was positively correlated to bruchid seed predation, but negatively related to ectophagous seed predation. There was a negative correlation between glandular fruit trichome length and parasitism rates of bruchids, suggesting that seed predation pressure may have produced evolutionary responses from plants (fruit trichome reduction), which should facilitate parasitoid action.

Structural diversity of the wood of temperate species of Acacia s.s. (Leguminosae: Mimosoideae)

Acacia s.s. comprises approximately 1020 species (i.e. just under one-third of all mimosoid legumes) and is almost entirely restricted to, although widespread, on the Australian continent. We investigated variation in the wood anatomy of 12 species from temperate New South Wales in a study concentrating on four recognised taxonomic sections (Botrycephalae, Juliflorae, Phyllodineae and Plurinerves), to elucidate which characteristics are consistent within the sections, having removed climatic effect as much as possible. The sections had great utility in species identification, whereas none of the wood characters reflected the hypothesised phylogeny of the genus. The main consistent difference among species was in ray width (uniseriate versus 1–3 cells wide). All species had distinct growth rings. The vessels had alternate vestured pitting and simple perforation plates. Fibres were generally thick-walled, and many fibres had a gelatinous inner wall (tension wood fibres) and were inconsistently distributed. Axial parenchyma was mainly paratracheal, ranging from vasicentric to confluent and varied greatly in abundance. Prismatic crystals were usually present in chambered fibres and axial parenchyma strands, and also varied in abundance. The variation in these qualitative characters obscures taxonomic differences, but may allow inferences to be made about environmental adaptation.

Characterization of Brazilian accessions of wild Arachis species of section Arachis (Fabaceae) using heterochromatin detection and fluorescence in situ hybridization (FISH)

The cytogenetic characterization of Arachis species is useful for assessing the genomes present in this genus, for establishing the relationship among their representatives and for understanding the variability in the available germplasm. In this study, we used fluorescence in situ hybridization (FISH) to examine the distribution patterns of heterochromatin and rDNA genes in 12 Brazilian accessions of five species of the taxonomic section Arachis. The heterochromatic pattern varied considerably among the species: complements with centromeric bands in all of the chromosomes (A. hoehnei) and complements completely devoid of heterochromatin (A. gregoryi, A. magna) were observed. The number of 45S rDNA loci ranged from two (A. gregoryi) to eight (A. glandulifera), while the number of 5S rDNA loci was more conserved and varied from two (in most species) to four (A. hoehnei). In some species one pair of 5S rDNA loci was observed adjacent to 45S rDNA loci. The chromosomal markers revealed polymorphism in the three species with more than one accession (A. gregoryi, A. magna and A. valida) that were tested. The previous genome assignment for each of the species studied was confirmed, except for A. hoehnei. The intraspecific variability observed here suggests that an exhaustive cytogenetic and taxonomic analysis is still needed for some Arachis species.

Phylogeny of New World Salvia subgenus Calosphace (Lamiaceae) based on cpDNA (psbA-trnH) and nrDNA (ITS) sequence data

Salvia subgenus Calosphace (Lamiaceae) is economically and ethnomedicinally significant and comprised of more than 500 species. Although strongly supported as monophyletic, it has received no comprehensive systematic research since the initial establishment of 91 taxonomic sections in 1939. Representative taxa of 73 sections of Calosphace were sampled to investigate the phylogenetic relationships and identify major lineages using chloroplast (intergenic spacer psbA-trnH) and nuclear ribosomal DNA (internal transcribed spacer). Phylogenetic analysis of the combined data sets established monophyly of seven sections (Blakea, Corrugatae, Erythrostachys, Hastatae, Incarnatae, Microsphace, and Sigmoideae) and four major lineages (S. axillaris, "Hastatae clade", "Uliginosae clade", and "core Calosphace"). Sections spanning two or more centers of diversity are not supported by our results; rather, supported relationships exhibit significant geographic structure. Mexico is supported as the geographic origin of Calosphace, and no more than seven dispersal events to South America are required to account for current disjunct distributions.

Abundant microsatellite diversity and oil content in wild Arachis species.

The peanut (Arachis hypogaea) is an important oil crop. Breeding for high oil content is becoming increasingly important. Wild Arachis species have been reported to harbor genes for many valuable traits that may enable the improvement of cultivated Arachis hypogaea, such as resistance to pests and disease. However, only limited information is available on variation in oil content. In the present study, a collection of 72 wild Arachis accessions representing 19 species and 3 cultivated peanut accessions were genotyped using 136 genome-wide SSR markers and phenotyped for oil content over three growing seasons. The wild Arachis accessions showed abundant diversity across the 19 species. A. duranensis exhibited the highest diversity, with a Shannon-Weaver diversity index of 0.35. A total of 129 unique alleles were detected in the species studied. A. rigonii exhibited the largest number of unique alleles (75), indicating that this species is highly differentiated. AMOVA and genetic distance analyses confirmed the genetic differentiation between the wild Arachis species. The majority of SSR alleles were detected exclusively in the wild species and not in A. hypogaea, indicating that directional selection or the hitchhiking effect has played an important role in the domestication of the cultivated peanut. The 75 accessions were grouped into three clusters based on population structure and phylogenic analysis, consistent with their taxonomic sections, species and genome types. A. villosa and A. batizocoi were grouped with A. hypogaea, suggesting the close relationship between these two diploid wild species and the cultivated peanut. Considerable phenotypic variation in oil content was observed among different sections and species. Nine alleles were identified as associated with oil content based on association analysis, of these, three alleles were associated with higher oil content but were absent in the cultivated peanut. The results demonstrated that there is great potential to increase the oil content in A. hypogaea by using the wild Arachis germplasm.

Rapid diversification of Tragopogon and ecological associates in Eurasia

Tragopogon comprises approximately 150 described species distributed throughout Eurasia from Ireland and the UK to India and China with a few species in North Africa. Most of the species diversity is found in Eastern Europe to Western Asia. Previous phylogenetic analyses identified several major clades, generally corresponding to recognized taxonomic sections, although relationships both among these clades and among species within clades remain largely unresolved. These patterns are consistent with rapid diversification following the origin of Tragopogon, and this study addresses the timing and rate of diversification in Tragopogon. Using BEAST to simultaneously estimate a phylogeny and divergence times, we estimate the age of a major split and subsequent rapid divergence within Tragopogon to be ~2.6 Ma (and 1.7-5.4 Ma using various clock estimates). Based on the age estimates obtained with BEAST (HPD 1.7-5.4 Ma) for the origin of crown group Tragopogon and 200 estimated species (to accommodate a large number of cryptic species), the diversification rate of Tragopogon is approximately 0.84-2.71 species/Myr for the crown group, assuming low levels of extinction. This estimate is comparable in rate to a rapid Eurasian radiation in Dianthus (0.66-3.89 species/Myr), which occurs in the same or similar habitats. Using available data, we show that subclades of various plant taxa that occur in the same semi-arid habitats of Eurasia also represent rapid radiations occurring during roughly the same window of time (1.7-5.4 Ma), suggesting similar causal events. However, not all species-rich plant genera from the same habitats diverged at the same time, or at the same tempo. Radiations of several other clades in this same habitat (e.g. Campanula, Knautia, Scabiosa) occurred at earlier dates (45-4.28 Ma). Existing phylogenetic data and diversification estimates therefore indicate that, although some elements of these semi-arid communities radiated during the Plio-Pleistocene period, other clades sharing the same habitat appear to have diversified earlier.

Chemotaxonomic markers in essential oils of Hypenia (Mart. ex Benth.) R. Harley

Central Brazilian Cerrado is regarded as the center of origin and dispersion of Hypenia (Lamiaceae: subtribe Hyptidineae) in South America. The genus has either remained undivided or been divided into two or seven taxonomic sections, based almost exclusively on a limited range of floral features. Interspecific chemical delimitation to complement analyses of botanical traits is described. Multivariate analysis of essential oils of ten species in the vegetative stage supports the taxonomic division in two sections. Cluster I included four species belonging to section Laxiflorae in addition to H. irregularis, which were characterized by the highest percentages of spathulenol and caryophyllene oxide. Cluster II contained five species belonging to section Densiflorae with α-cadinol, α-muurolene and a-muurolol as major constituents. Cadinanes and germacranes/ aromadendranes seem to be chemotaxonomic markers of sections Densiflorae and Laxiflorae, respectively. Furthermore, redundancy analysis revealed no significant correlation between edaphic factors and oil chemovariations, suggesting that Hypenia oils consist of constitutive rather than induced compounds.

Nutlet micro‐morphology of the genus Microula (Boraginaceae) from the Qinghai–Tibetan Plateau, and its systematic implications

The micro‐morphology of nutlets in 30 taxa (28 species and 2 varieties) of Microula Benth. (Boraginaceae) was surveyed by light and scanning electron microscopy. A principal coordinate‐based ordination analysis (PCO) (8 morphological and 14 micro‐morphological characters) was applied to explore whether taxa clustered according to the current sectional taxonomy. The nutlet epidermis showed three major features: trichomes, papillae and lamellae. Two basic trichome types could be identified: branched and unbranched. Stellate trichomes (STT) and stipitate stellate trichomes (SST) can be considered as two subtypes of branched trichomes based on shape and branching location. Three kinds of unbranched trichomes were recognized by their shapes: slender trichomes (SLT), spear‐like trichomes (SPT) and conical trichomes (CT). Four types of papillae were revealed in this genus: central apiculate papillae (CAP), debris‐covered convex papillae (DCP), rugous papillae (RP) and tabular papillae (TP). The lamellae was classified in five types: glossy lamellae (GL), thread‐like lamellae (TL), rugous lamellae (RL), interrupted lamellae (IL) and debris‐covered lamellae (DCL). The variation in the nature of surface sculpturing, nutlet shape and size, dorsal aperture shape, and attachment scar positions proved useful diagnostic characters. Taxa belonging to the same section generally clustered together in the PCO analysis. A key based on the morphology and micro‐morphology of nutlets is provided to distinguish the sections of Microula. The presence of SLT, STT, DCP and DCL is consistent with the macro‐morphological classification and provides additional evidence for the subgeneric delimitations. The SST, SLT, CAP, DCP, RP, DCL, GL and RL are useful in discriminating species in Microula. Additionally, the distribution of some trichomes, papillae and lamellae types is correlated with the altitudinal distribution of the species.

Seedling resistance to Phytophthora cinnamomi in the genus Abies

Root rot and stem canker caused by Oomycete species belonging to the genus Phytophthora often seriously limit culture of true firs (Abies spp.) An investigation of the variation of resistance among Abies species to Phytophthor a cinnamomi was carried out to identify potential sources of resistance in the genus. Thirty-two Abies species were grown in a greenhouse for 2 and/or 3 years from seed. Seedlings were moved to an outdoor lath house, inoculated with rice grains colonized with P. cinnamomi, and subsequent mortality was assessed biweekly for 16 weeks. Disease developed rapidly resulting in 88.1 % overall mortality 16 weeks after inoculation. Mortality was less in two of the eight taxonomic sections of the genus evaluated, Momi (0.65 ± 0.0252) and Abies (0.79 ± 0.0193). Mortality in all other sections exceeded 93 %. Final species mortality ranged from 10.6 % (Abies firma) to 100.0 % (several species). Although several caveats apply, results have identified potential sources of Abies to be used as (1) resistant planting stock, (2) grafting rootstock, and (3) parents in hybridization/backcrossing programs in order to mitigate losses caused by P. cinnamomi.

Flowers and floral biology of the holy grasses (Hierochloe and Anthoxanthum: Aveneae, Gramineae)

Trifloreted spikelets in species of Anthoxanthum and of Hierochloe are united by the syndrome of two lower male or neuter florets and a differentiated third floret, perfect, bistaminate, and protogynous. Differences in presentation of the floral organs from the third anthoecium separate the genera. Anthers in Anthoxanthum, longer than the f3 anthoecium, keep it open until they migrate on elongating filaments, following behind the protogynous stigma-styles. Both emerge near the apex of the upper glume which tightly encloses all three florets. In Hierochloe the uppermost anthoecium is closed over the androecium and gynoecium until lodicule-controlled anthesis when stigma-styles are exserted unhindered by glumes, and the anthers are exserted later on long filaments from the chasmogamous lower florets. In Hierochloe triandrous lower florets are constant. In Anthoxanthum the two lower florets are neuter in Eurasian species, but in species in Africa, Asia, and Malesia, sometimes f1 florets are also staminate, and very exceptionally both florets present stamens. These reflect a sexual variability in Anthoxanthum unknown in Hierochloe. Data from flowers of 30 species of Hierochloe and 17 species of Anthoxanthum are tabulated; included are ratios of f3 anthers:anthoecium and stigma-styles:the upper glume, G2, two ratios which most reliably reflect the intergeneric floral patterns. Pathways to those varied floral systems are outlined. A sectional taxonomy is proposed for Hierochloe: Sect. Hierochloe autonymum; Sect. nova Monoecia for species in South America where monoecism occurs in all taxa. Andromonoecism is the predominant sexual system in boreal and austral species of Hierochloe, but is interrupted by apomixis in northern Europe.

Establishing dates of valid publication for Luigi Buscalioni's names in Saurauia (Actinidiaceae)

AbstractLuigi Buscalioni published 119 names of species and infraspecific taxa of Saurauia in many installments over a 16‐year period from 1912 and 1927. Buscalioni's work had formal taxonomic sections, which he likely intended as place of valid publication for his names. Nevertheless, most of his names were published with diagnostic or descriptive information in many parts of his works, often earlier than his formal descriptions. The citations of names in Buscalioni's work are summarized, and dates and citations for validation of names are provided.

Rapid identification of Aspergillus fumigatus within the section Fumigati

BackgroundNew fungal species that are morphologically similar to Aspergillus fumigatus were recently described and included in section Fumigati. Misidentification of such fungal species, particularly of the human pathogens, Aspergillus lentulus, Neosartorya fischeri, Neosartorya hiratsukae, Neosartorya pseudofischeri and Neosartorya udagawae, has been increasingly reported by numerous clinical labs. Nevertheless, A. fumigatus still accounts for more than 90% of all invasive aspergillosis cases. The purpose of the present study was to develop a rapid method for the molecular identification of A. fumigatus to distinguish it from other species within the section Fumigati.ResultsA multiplex PCR was developed using prior information based on β-tubulin (βtub) and rodlet A (rodA) partial gene sequences. PCR amplification of βtub and rodA fragments resulted in a distinctive electrophoretic pattern in A. fumigatus and N. udagawae. The polymorphisms found in the smallest amplified sequence of βtub (153 bp) and rodA (103 bp) genes were then compared among and within species of this taxonomic section. βtub was able to differentiate among 13 individual species and two groups of species that included the pathogenic fungus A. lentulus. A more limited number of sequences were available for rodA; nevertheless, we were able to distinguish Aspergillus viridinutans, N. hiratsukae and N. udagawae.ConclusionsThe assay described in the present study proved to be specific and highly reproducible, representing a fast and economic way of targeting molecular identification of the relevant mould, A. fumigatus, in clinical laboratories.

Phylogenetic analyses of DNA sequences with chromosomal and morphological data confirm and refine sectional and series classification within Melampodium (Asteraceae, Millerieae)

AbstractThe genus Melampodium consists of 40 species distributed throughout Mexico and Central America with extensions into the southwestern United States and Colombia and Brasil of South America. The genus reflects broad chromosomal evolution involving dysploidy and polyploidy withn = 9, 10, 11, 12, 14, 18, 20, 23, 24, 27, 28, 30, and 33 having been documented (x = 9, 10, 11, 12, and 14). The most recent classification of the genus, based primarily on morphology and chromosome num bers, recognized six taxonomic sections: Alcina, Bibractiaria, Melampodium, Rhizomaria, Serratura, and Zarabellia. Section Melampodium, which contains 22 species, was divided into five series: Cupulata, Leucantha, Longipila, Melampodium, and Sericea. This hypothesis had been tested by previous morphological phenetic and cladistic analyses, and several problem areas had been highlighted, especially involving section Alcina, but no modifications to the classification have been made. Recent molecular studies utilizing nrITS, 5S rDNA spacer and low‐copy nuclear PgiC gene, plus plastid matK and psbA‐trnH regions allow the classificatory hypothesis to be tested more precisely. Congruence between ITS and matK phylogenies for all species reveals sections Bibractiaria, Rhizomaria, and Serratura to be holophyletic. The largest section Melampodium is holophyletic with both plastid markers, but M. longipilum is shown as an outlier (tying to sect. Rhizomaria) in all nuclear marker phylogenies (ITS, PgiC and 5S rDNA spacer). Section Zarabellia appears holophyletic in matK but biphyletic with ITS, suggesting recogni tion of two distinct series. Section Alcina is the most problematic, being triphyletic in ITS and matK, and with the species not connecting to the same relatives. These insights recommend recognition of three sections from within section Alcina, one hous ing M. nutans (Nutantia Stuessy, sect. nov.) another M. glabrum (Glabrata Stuessy, sect. nov.) and a third M. perfoliatum (sect. Alcina (Cav.) DC.). These may represent ancient independent lines that have diverged from original x = 11 ancestors. Within section Melampodium, 5S rDNA NTS, PgiC and psbA‐trnH, in addition to ITS and matK, provide insights on relationships among taxonomic series. Series Leucantha and Longipila are holophyletic, and series Cupulata nearly so, with M. glabribracteatum deserving treatment in a series of its own. The most complex relationships are between series Melampodium, Cupulata, and Sericea, the latter comprising five exclusively polyploid taxa (4x and 6x). Molecular and cytogenetic data reveal allopolyploid origins for all of these polyploids, in some cases involving hybridization between the two series Cupulata and Melampodium / Sericea, such as with M. mayfieldii and M. longicorne, which exacerbates taxonomic circumscription.

An overview of peanut and its wild relatives

The legumeArachis hypogaea, commonly known as peanut or groundnut, is a very important food crop throughout the tropics and sub-tropics. The genus is endemic to South America being mostly associated with the savannah-like Cerrado. All species in the genus are unusual among legumes in that they produce their fruit below the ground. This profoundly influences their biology and natural distributions. The species occur in diverse habitats including grasslands, open patches of forest and even in temporarily flooded areas. Based on a number of criteria, including morphology and sexual compatibilities, the 80 described species are arranged in nine infrageneric taxonomic sections. While most wild species are diploid, cultivated peanut is a tetraploid. It is of recent origin and has an AABB-type genome. The most probable ancestral species areArachis duranensisandArachis ipaënsis, which contributed the A and B genome components, respectively. Although cultivated peanut is tetraploid, genetically it behaves as a diploid, the A and B chromosomes only rarely pairing during meiosis. Although morphologically variable, cultivated peanut has a very narrow genetic base. For some traits, such as disease and pest resistance, this has been a fundamental limitation to crop improvement using only cultivated germplasm. Transfer of some wild resistance genes to cultivated peanut has been achieved, for instance, the gene for resistance to root-knot nematode. However, a wider use of wild species in breeding has been hampered by ploidy and sexual incompatibility barriers, by linkage drag, and historically, by a lack of the tools needed to conveniently confirm hybrid identities and track introgressed chromosomal segments. In recent years, improved knowledge of species relationships has been gained by more detailed cytogenetic studies and molecular phylogenies. This knowledge, together with new tools for genetic and genomic analysis, will help in the more efficient use of peanut's genetic resources in crop improvement.

The Ophryotrocha labronica group (Annelida: Dorvilleidae)— with the description of seven new species

This paper reviews the group of gonochoristic Ophryotrocha species, known as the “O. labronica group”. This informal group is chararacterised by its unique maxillary P- and K-forceps and dorsomedian rosette glands. All members of the group are primarily gonochoristic and almost all have the diploid complement of chromosomes of 2n = 6. External morphological differences within the group are very slight. In males and females of all species the P-type maxillae change at maturity to the K-type with the right forceps being bifid. A jaw fossil from the Upper Cretaceous, attributable to the O. labronica group, attests to the long history of the group. As herein defined, the group includes: O. labronica labronica, O. labronica pacifica, O. costlowi sp. nov., O. dimorphica, O. japonica sp. nov., O. macrovifera sp. nov., O. notoglandulata, O. permanae sp. nov., O. robusta sp. nov., O. rubra sp. nov., O. schubravyi, O. vellae sp. nov., O. olympica, nom. nud., O. prolifica, nom. nud., and O. sativa, nom. nud.. Seven species are formally described and diagnoses are provided for all remaining taxa in the taxonomic section. This is followed by an illustrated discussion of the morphology, reproductive traits, and relationships of the members of the informal group.