The taxonomy of the family Paramphistomidae Fischoeder, 1901 with special reference to the morphology of species occurring in ruminants IV. Revision of the genusGigantocotyle Näsmark, 1937 and elevation of the subgenusExplanatum Fukui, 1929 to full generic status

Summary The genusGigantocotyle Näsmark, 1937 is redefined and restricted to contain four valid species, namely,G. gigantocotyle (Brandes in Otto, 1896) Näsmark, 1937 (type species);G. formosanum (Fukui, 1929) Näsmark, 1937;G. symmeri Näsmark, 1937 andG. duplicitestorum Näsmark, 1937.G. lerouxi Yeh, 1957 is regarded as a synonym ofG. symmeri Näsmark, 1937.The subgenusExplanatum Fukui, 1929 is redefined and raised to full generic rank to contain three valid species, namely,E. explanatum (Creplin, 1847) Fukui, 1929;E. bathycotyle (Fischoeder, 1901) Yamaguti, 1958 andE. anisocotylea (Faust, 1920) Yamaguti, 1958.Paramphistomum siamense Stiles & Goldberger, 1910 andP. fraternum Stiles & Goldberger, 1910 are considered synonyms ofExplanatum explanatum (Creplin, 1847) Fukui, 1929.The valid species are redescribed and illustrated and scanning electron microphotographs of the tegumental surfaces of some species are provided. A key to the species of each genus is given.Part of a thesis approved by the University of London for the award of the Ph.D. degree.Part of a thesis approved by the University of London for the award of the Ph.D. degree.     

Molecular data reveal that the tetraploid Tragopogon kashmirianus (Asteraceae: Lactuceae) is distinct from the North American T. mirus

Tragopogon kashmirianus (Asteraceae: Lactuceae) (2n = 24) was described based on collections from Kashmir. The tetraploid is morphologically similar to allotetraploid T. mirus from North America that has formed in western North America from the introduced T. dubius (2n = 12) and T. porrifolius (salsify; 2n = 12). Singh and Kachroo (1976 ) suggested that T. kashmirianus might have formed from the same diploid parental combination as T. mirus. To determine this, we investigated internal and external transcribed spacers (ITS, ETS) and five plastid regions of T. kashmirianus and species reported from Kashmir, northern India and neighbouring countries (T. badachschanicus, T. longirostris, T. porrifolius, T. pratensis, T. orientalis, T. subalpinus, T. trachycarpus, T. gracilis and T. dubius). Molecular data indicate that the parents of T. kashmirianus are not the European T. porrifolius and T. dubius. The exact parentage of T. kashmirianus is still unclear, but if it is an allotetraploid, at least one parent is a species native to Kashmir/India. Alternatively, it may represent an autopolyploid, again with the diploid parent native to Kashmir/India. We also found that ‘T. dubius’ from Kashmir is phylogenetically and morphologically distinct from collections of T. dubius from Europe and probably represents a previously unrecognized species. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 391–398.     

Additional evidence implicating Triticum searsii as the B-genome donor to wheat

In vitro DNA:DNA hybridizations and hydroxyapatite thermal-elution chromatography were employed to identify the diploid wheat species ancestral to the B genome of Triticum turgidum. ³H-T. turgidum DNA was hybridized to the unlabeled DNAs of T. urartu, T. speltoides, T. sharonensis, T. bicorne, T. longissimum, and T. searsii. ³H-Labeled DNAs of T. monococcum and a synthetic tetraploid AADD were hybridized with unlabeled DNAs of T. urartu and T. searsii to determine the relationship of the A genome of polyploid wheat and T. urartu. The heteroduplex thermal stabilities indicated that T. searsii was most closely related to the B genome of T. turgidum (AB) and that the genome of T. urartu and the A genome have a great deal of base-sequence homology. Thus, it appears that T. searsii is the B-genome donor to polyploid wheat or a major chromosome donor if the B genome is polyphyletic in origin.Published with the approval of the Director of The West Virginia Agricultural Experiment Station as Scientific Paper No. 1837.     

A new species of Trichogramma (Hymenoptera: Trichogrammatidae) parasitic on eggs of the alderfly Sialis melania (Neuroptera: Sialidae) from Japan,with comments on its phylogeny and male wing polymorphism

A new species of Trichogramma that parasitizes Sialis melania eggs is described as Trichogramma tajimaense Yashiro, Hirose and Honda, sp. nov. from Japan. Its phylogenetic position is based on a DNA‐based analysis, and data regarding its male wing polymorphism are also presented. The view that T. tajimaense is closely related to T. semblidis, another parasitoid of Sialis eggs, is supported by the results of a phylogenetic analysis, as well as by the biological and morphological similarities between both species. Trichogramma tajimaense is also similar in male wing polymorphism to T. kurosuae, a gregarious egg parasitoid of the lepidopteran Ivela auripes, as both Trichogramma species exhibit male wing trimorphism (fully alate, brachypterous and apterous forms) in contrast to the male wing dimorphism (fully alate and apterous forms) of T. semblidis. However, no phylogenetic analysis reveals a close relationship between T. tajimaense and T. kurosuae, and a difference exists between these two species in the mean percentage of flightless (brachypterous and apterous) males that emerge from a host egg mass; 96% of T. tajimaense males are incapable of flight, whereas about 50% of T. kurosuae males are flightless. Because all or almost all males of T. semblidis parasitizing Sialis eggs are apterous, T. tajimaense is more similar to T. semblidis than to T. kurosuae in the proportion of flightless males. In addition, male wing polymorphisms of Trichogramma in relation to mating systems could also show a similarity between T. tajimaense and T. semblidis when considering both species as quasi‐gregarious parasitoids of Sialis eggs.     

A morphological reappraisal of Tubifex blanchardi Vejdovský, 1891 (Clitellata: Tubificidae)

Tubifex blanchardi Vejdovský, 1891 is a freshwater tubificid, often living in sympatry with Tubifex tubifex (Müller 1774). Although considered from its discovery as a species on its own, its biological status is debated. During the early seventies T. blanchardi was reduced to a mere form of T. tubifex, as a particular case of polymorphism in chaetal pattern. Using classical histological techniques, microdissections of portions of the male genital apparatus and phalloidin staining of dissected copulatory organs we investigated 163 mixed individuals of T. blanchardi and T. tubifex belonging to sympatric populations from the Lambro River (Milan, Northern Italy). The internal morphology of T. blanchardi is described for the first time. Our results show that T. tubifex and T. blanchardi differ in several characters concerning both their external and internal morphology, and in the fine organization of their copulatory organs. Several independent character sets support the separation of T. blanchardi from T. tubifex, suggesting that it is an independent species. This study also supports the idea that T. blanchardi and T. bergi (Hrabě, 1935), another species closely related to T. tubifex, are not conspecific. The observed morphological differences between allopatric populations of T. tubifex are discussed.     

ELECTROPHORETIC STUDY OF THE ALLOPOLYPLOIDAL ORIGIN OF TALINUM TERETIFOLIUM AND THE SPECIFIC STATUS OF T. APPALACHIANUM (PORTULACACEAE)

Electrophoretic evidence supported the hypothesis that Talinum teretifolium is an allopolyploid derivative of T. mengesii and T. parviflorum. Electrophoretic variation was examined for 384 individuals from 21 populations of four Talinum species. Plants were scored for isozymes of nine enzyme systems specified by 23 gene loci of which 4 were monomorphic and 19 polymorphic. Talinum teretifolium populations were electrophoretically uniform, and all alleles of this species were accounted for by combining alleles present in its presumed parents. Genetic identity values between T. teretifolium and each of its presumed parents (I ≥ 0.817) were higher than between any other pair of the four Talinum species examined. The electrophoretic evidence did not support an alternative hypothesis that T. calycinum is a progenitor of T. teretifolium. Electrophoretic data also showed that T. appalachianum is a disjunct population of T. parviflorum. The average genetic identity between T. appalachianum and T. parviflorum (I = 0.884) was higher than the average genetic identity for conspecific populations of both T. mengesii and T. calycinum.     

MOLECULAR EVIDENCE FOR THE ORIGIN OF THE S-DERIVED GENOMES OF POLYPLOID TRITICUM SPECIES

The genus Triticum includes several polyploid species that arose due to hybridization between two or more diploid species. Section Sitopsis is comprised of five diploid species given the genome designation S. Four polyploid species are recognized that contain an S or S-derived genome. We have used two repetitive DNA sequences found primarily in the S genomes of Triticum to determine the likely diploid progenitors of the polyploid species. Comparison of restriction fragments that hybridize to probes for these sequences suggests that T. speltoides is distinct from other members of section Sitopsis (i.e., T. longissimum, T. bicorne, T. searsii, and T. sharonense). The S-derived genome of T. aestivum is more closely related to T. speltoides than to the other Sitopsis diploids. The restriction fragment pattern of T. timopheevii is 98% identical to that of T. speltoides, while those of T. kotschyi and T. syriacum are identical to the group of diploids represented by T. longissimum, T. bicorne, T. searsii, and T. sharonense. Our results are compatible with previous molecular and biochemical data regarding relationships among Triticum species containing an S or S-derived genome.     

Genetic polymorphism for cyanogenesis and linkage at the linamarase locus in Trifolium nigrescens Viv. subsp. nigrescens

Polymorphisms at two genetic loci conditioning the cyanogenic glucoside linamarin (Ac) and the glucosidase linamarase (Li) are reported for the first time in Trifolium nigrescens Viv. subspecies nigrescens (2n=2x=16). T. nigrescens is one of several possible ancestral species that may have donated a genome to the allotetraploid species white clover (T. repens L., 2n=4x=32). T. nigrescens is a strong candidate because it is the only very close relative that, like white clover, is cyanogenic. Genetic analysis showed that in T. nigrescens, cyanogenesis was inherited as a two-locus genetic system in a similar way to that in white clover. Furthermore, Li, which is linked to the locus Sdh (shikimate dehydrogenase, SDH) at a distance of 6 cM in one genome of white clover, also showed linkage (12 cM) in T. nigrescens. It is concluded that one of the subspecies of T. nigrescens is a likely donor of a genome to white clover. Received: 27 December 2000 / Accepted: 12 April 2001     

Interspecific relationships and biogeography of some Bornean tree shrews (Tupaiidae: Tupaia), based on DNA hybridization and morphometric comparisons1

The interspecific relationships and biogeography of seven southeast Asian tree shrew species in the genus Tupaia were examined by DNA hybridization and multivariate morphometric analysis. Urogale everetti served as the outgroup. DNA hybridization data indicate that T. tana is most closely related to T. tnontana, and they form a clade with T. minor. Morphometric comparisons indicate that T. tana and 77 minor, and 7. montana and T palawanensis, form groups that, together, are most similar to T. glis. T. javanica and U. everetti cluster outside the rest of Tupaia. The DNA hybridization data support a model of Bornean speciation driven by sea‐level changes. They also indicate either (1) that there is a large variation in the rate of tree shrew evolution or (2) that U. everetti may in fact be a member of the ingroup. When considered in light of the phylogenetic results, the morphometric data suggest substantial convergence in body size or correlation in character changes.     

New clade of silicified bolidophytes that belong to Triparma (Bolidophyceae,Stramenopiles)

The small phytoplankton genus Triparma belongs to the class Bolidophyceae and contains two distinct forms: silicified species and naked flagellated species (formerly Bolidomonas). Recent studies showed that four silicified species/strains (Triparma laevis f. inornata, T. laevis f. longispina, T. strigata, and T. aff. verrucosa) belong to a single clade that is paraphyletic, because it also contains an unclassified flagellated strain, and is sister to a flagellated species, T. eleuthera. In this study, we isolated and characterized two new strains of silicified species to test the phylogenetic unity of silicified bolidophytes. The isolates were identified as T. retinervis strains because they possessed fine areolation on the cell wall. 18S rDNA and rbcL phylogenetic analyses demonstrated that T. retinervis formed a new silicified clade that is sister to the flagellated species T. pacifica. This reveals that there are at least two distinct clades including both silicified and flagellated Triparma species.     

Phylogenetic and populational study of the Tuber indicum complex

When examined using SEM, Chinese samples of Tuber indicum and T. sinense displayed the same ascospore ornamentation as that of T. pseudohimalayense, T. indicum, collected in India by Duthie in 1899, and samples renamed T. himalayense in 1988. The different authors who named the four taxa (T. indicum, T. himalayense, T. sinense, T. pseudohimalyense) described differences in the surface of the peridium which could be considered as usual variations within a single species. We consider T. indicum, T. himalayense, T. sinense and T. pseudohimalayense as one species, T. indicum. Within this T. indicum complex, according to ITS and β-tubulin sequences, there are two groups in China, which could be considered as geographical ecotypes. This study is the first to identify a genetic and phylogeographical structure within the Chinese Tuber species.     

Genetic architecture of the Tetragonula carbonaria species complex of Australian stingless bees (Hymenoptera: Apidae: Meliponini)

A species complex is a group of closely related species whose ecological or morphological boundaries are sufficiently vague that delimiting one species from another is difficult. In Australia, a group of four stingless bee species – Tetragonula carbonaria Smith, Tetragonula hockingsi Cockerell, Tetragonula mellipes Friese, and Tetragonula davenporti Franck – form a species complex in which gross morphology is clinal and overlapping. The species are most readily distinguished by the morphology of their brood combs. Here we genetically characterize bees sampled in areas where the species do and do not have contact. Our data corroborate previous evidence that T. hockingsi and T. carbonaria are genetically distinct and that there are two genetically distinct groups of T. hockingsi – one in the north and the other in the south of Queensland. Curiously, northern populations of T. hockingsi, which are allopatric to T. carbonaria, are genetically closer to T. carbonaria than are southern populations of T. hockingsi, which are in sympatry with T. carbonaria. We detected three hybrid colonies that appear to have arisen because of anthropogenic movement of T. hockingsi colonies from north to south of Queensland where males mated with local T. carbonaria queens. We discuss the status of T. davenporti, a recently described species cryptically similar to T. hockingsi from south‐east Queensland. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113 , 149–161.     

Morphological and molecular evidence indicates that the Gulf Coast box turtle (Terrapene carolina major) is not a distinct evolutionary lineage in the Florida Panhandle

Four extant subspecies of Terrapene carolina in eastern North America, Terrapene carolina bauri, Terrapene carolina carolina, Terrapene carolina triunguis, and Terrapene carolina major, are recognized based on morphological studies. A fifth subspecies, Terrapene carolina putnami, has been described from Pleistocene deposits but is very similar morphologically to T. c. major. Questions concerning the relationship of the Gulf Coast box turtle (T. c. major) to other box turtles have been pervasive ever since it was described. We used a combined morphological and genetic analysis to address the status of T. c. major and other T. carolina lineages. Terrapene c. bauri, T. c. carolina, and T. c. triunguis are distinct based on a discriminate function analysis of 25 morphological characters, including characters traditionally used to assign subspecies. The results of the present study confirm that box turtles phenotypically diagnosed as T. c. bauri, T. c. carolina, and T. c. triunguis all occur within the hypothesized range of T. c. major, and that the latter does not possess a diagnosable morphology. The three morphological lineages also possess divergent mitochondrial haplotypes that are present within the hypothesized range of T. c. major. In addition, a fourth distinct mtDNA lineage co‐occurs within the putative range of T. c. major. This unique lineage may include mitochondrial DNA variation from the Pleistocene T. c. putnami. Analysis of nine nuclear DNA microsatellites revealed no population structure in box turtles currently assigned to T. c. major from the Florida Panhandle, suggesting a complete admixture of lineages in this region. The results of the present study indicate that box turtles traditionally assigned to T. c. major based on phenotype are the result of introgression between eastern extant (predominantly T. c. carolina) and an extinct subspecies, T. c. putnami. Published 2011. This article is a US Government work and is in the public domain in the USA. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 889–901.     

Genome identification of the Triticum crassum complex (Poaceae) with the restriction patterns of repeated nucleotide sequences

Species of the Triticum crassum complex, tetraploid and hexaploid T. crassum, hexaploid T. juvenale, and hexaploid T. syriacum, share a similar morphology. Variation in the restriction profiles of nuclear repeated nucleotide sequences is employed in identification of genomes of these species. The data show that hexaploid T. crassum originated from hybridization of the tetraploid cytotype of T. crassum with T. tauschii. Triticum juvenale and T. syriacum originated from hybridization of tetraploid T. crassum with T. umbellulatum and T. searsii, respectively. Tetraploid T. crassum appears to be an ancient allotetraploid that originated from hybridization of primitive T. tauschii with an ancient species in the evolutionary lineage leading to the section Sitopsis of the genus Triticum.     

CYTOGENETIC STUDIES IN THE GENUS TRIBOLIUM (POACEAE: ARUNDINEAE)

The genus Tribolium Desv. consists of nine species, i.e., T. utriculosum (Nees) Renv., T. ciliare (Stapf) Renv., T. echinatum (Thunb.) Desv., T. hispidum (Thunb.) Desv., T. acutiflorum (Nees) Renv., T. obliterum sensu Davidse, T. glomeratum sensu Davidse, T. uniolae (L.f.) Renv., and T. brachystachyum (Nees) Renv. The genus has a basic chromosome number of 6, and from diploid to hexaploid specimens have been examined. Precocious segregation of metaphase I bivalents were observed in four species. Multivalent formation results in unequal chromosome segregation during anaphase I, and several cells with an 11–13 chromosome distribution have been observed. The presence of univalents and anaphase I bridges in all T. brachystachyum specimens suggests a hybrid origin for the species. B-chromosomes were present in specimens from four species. The B-chromosomes are similar to the euchromosomes with the exception that they do not participate in meiosis. The B-chromosomes have a possible isochromosome origin. The cytogenetic evidence presented supports the combination of Plagiochloa and Lasiochloa into Tribolium and indicates that the genus is closely related to Urochlaena, whereas it is not closely related to Prionanthium.     

The origins of the genomes of Triticum biunciale,t. ovatum,t. neglectum,t. columnare,and t. rectum (poaceae) based on variation in repeated nucleotide sequences

The origins of the genomes of allotetraploid species Triticum biunciale, T. ovatum, T. neglectum, and T. columnare, and allohexaploid T. rectum were investigated by examining the presence of specific restriction fragments of repeated nucleotide sequences in DNAs of the polyploid species. The restriction fragments were detectable either in a single diploid Triticum species (unique characters) or a group of diploid species (unique shared characters). The analysis showed that Triticum biunciale and T. ovatum are closely related. In both species, one pair of genomes is closely related to the genome of T. umbellulatum and the other is a modified genome of T. comosum. The same genome formula, UUM°M°, is proposed for T. biunciale and T. ovatum. Potential reasons for the modification of the M° genome are discussed. Triticum neglectum and T. columnare are also closely related to each other and have the same genomes. They share the U genome with T. biunciale and T. ovatum, but their second pair of genomes is unrelated to the M° genome. No relationship was found of this genome to a genome of any extant diploid species of Triticum or any phylogenetic lineage leading to the extant diploid species. This unknown genome is designated X'.∗∗∗ The proposed genome formula for T. neglectum and T. columnare is UUX'X'∗∗∗. Hexaploid T. rectum originated from hybridization of one of the tetraploid species with the formula UUX'X', likely T. neglectum, with T. uniaristatum (genome N), and its genome formula is UUX'X'NN.     

Additional origins of Ownbey's Tragopogon mirus

The allotetraploids (2n = 24) Tragopogon mirus and T. miscellus have become textbook examples of recently and recurrently formed allopolyploids. Both species formed following the introduction of three diploids, T. dubius, T. porrifolius and T. pratensis (each with 2n = 12), from Europe into the Palouse region of eastern Washington and adjacent Idaho, USA, in the early 1900s. The parentage of both allotetraploids is well documented (T. mirus = T. dubius × T. porrifolius; T. miscellus = T. dubius × T. pratensis), and both allotetraploids have formed repeatedly in the past approximately 80 years in the Palouse. On a larger geographical scale, T. mirus has also been reported from Flagstaff, Arizona (AZ), and more recently from Oregon (OR). However, the populations from OR and AZ have not been previously analysed with molecular markers to test the hypothesis of separate origin (vs. long‐distance dispersal). Here, we show that both the AZ and OR collections of T. mirus combine distinctive parental genotypes and are genetically differentiated from the T. mirus genotypes found in the Palouse. The OR sample of T. mirus has a genetically distinct T. dubius contribution that forms a clade in our analyses with a sample of what has been referred to as T. major (now considered a subspecies of T. dubius). Consistent with other naturally occurring T. mirus populations, plastid sequences indicate that T. porrifolius was the maternal parent for both the AZ and OR collections. Microsatellite data are also consistent with local formation of T. mirus from co‐occurring populations of T. dubius and T. porrifolius in OR and AZ. As with sequence data, T. dubius from OR is distinct from other samples of T. dubius at microsatellite loci, contributing a unique signature to T. mirus from this location. It will be useful to include these additional geographical origins of T. mirus, particularly the more genetically distant sample from OR, in ongoing investigations of the genetic and genomic consequences of recent allopolyploidy. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169 , 297–311.