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Choi YJ  Thines M  Runge F  Hong SB  Telle S  Shin HD 《Fungal biology》2011,115(2):102-111
Bremia lactucae is one of the most important pathogens in lettuce production. Recent molecular?studies revealed considerable genetic variation in this species complex. However, only few accessions from the same host have been examined for most species and no study investigating the morphological distinctiveness of phylogenetic lineages of Bremia has so far been reported. Thus it is believed that morphological species delimitation in Bremia is not feasible. In the present study, multiple accessions of neglected species, which had been described decades ago, but have not been widely accepted, were investigated, considering both multi-gene phylogenies and morphological characters. All previously described species from host genera other than Lactuca investigated, Bremia microspora, Bremia ovata, Bremia saussureae, and Bremia sonchicola, could be confirmed as distinct, host-specific entities. Also, morphological characteristics of their conidiophores and conidia allowed delimitation of these species. Therefore, not only the wide species concept to merge all Bremia species on the Asteraceae under B. lactucae is inappropriate but also their delimitation on the basis of morphological characters seems feasible. In addition, it has been shown that Bremia elliptica is phylogenetically distinct from the other species infecting the genus Lactuca, B. lactucae. It is therefore concluded that B. lactucae is most likely limited to Lactuca sativa and closely-related species, and that most species of Bremia are highly host specific. This finding might stimulate the search for durable resistance genes in genera closely related to the genus Lactuca and in divergent species of the genus itself.  相似文献   

3.
Compsilura concinnata (Meigen) is one of the most famous, most polyphagous and most widely distributed tachinid flies (Diptera, Tachinidae) in the world. This species is well known as a biocontrol agent of some injurious pests of cultural and wild plants and has been introduced from Europe to the United States to control mainly the gypsy moth. Recently we found three new species very closely resembling C. concinnata from Southeast and East Asia: C. lobata sp. nov. (Japan and Thailand), C. malayana sp. nov. (Malaysia) and C. pauciseta sp. nov. (Japan and Taiwan). Additionally, C. samoaensis Malloch is treated as a junior synonym of C. concinnata based on the examination of the type specimen. The genetic differences in the mitochondrial COI gene data are examined to assess the accuracy of species delimitation of Compsilura. The male postabdominal characters of these species are illustrated. The piercing female postabdomen of C. concinnata is illustrated and compared to those of other members belonging to the Blondelia group including Blondelia Robineau-Desvoidy, Celatoria Coquillett, Eucelatoria Townsend and Vibrissina Rondani.  相似文献   

4.
A new species of Cremosperma (Gesneriaceae, tribe Beslerieae) is described from the Chocó floristic region of the western Andean slopes of northern Ecuador and southern Colombia. The dorsiventral shoots and strongly anisophyllous leaves differentiate Cremosperma anisophyllum from all other congeners.  相似文献   

5.
Four sympatric forms of the genus Garra (Cyprinidae) differring in external morphology are reported from the middle reaches of the Sore River belonging to the White Nile system in southwestern Ethiopia. Additionaly, two Garra specimens exhibiting unusual morphology are reported from the same river. One of them posseses ??rubber lips??, a morphological modification previously unknown for the genus, another exhibits the morphological characters indicating its predatory feeding habits. The reasons to consider the forms of Garra from the Sore River as a presumptive species flock are briefly discussed.  相似文献   

6.
A new species of amphistome digenean from the stomach and intestine of Podocnemis expansa (Pelomedusidae), of the tropical rain forest, from the State of Pará, Brazil, is described and allocated to a new genus ( Oriximinatrema noronhae ). The new species is characterized by the presence of an esophageal bulb, an esophageal extension uncovered by an extension of the pharyngeal sacs, a well-developed cirrus sac, post-bifurcal genital sucker, a ventro-terminal acetabulum with an anterior lip, and medium-sized eggs. This is the first report of a Dadayiinae trematode infecting a reptilian host.  相似文献   

7.
Tropical forests harbor extremely high levels of biological diversity and are quickly disappearing. Despite the increasingly recognized high rate of habitat loss, it is expected that new species will be discovered as more effort is put to document tropical biodiversity. Exploring under‐studied regions is particularly urgent if we consider the rapid changes in habitat due to anthropogenic activities. Madagascar is known for its extraordinary biological diversity and endemicity. It is also threatened by habitat loss and fragmentation. It holds more than 100 endemic primate species (lemurs). Among these, Microcebus (mouse lemurs) is one of the more diverse genera. We sampled mouse lemurs from several sites across northern Madagascar, including forests never sampled before. We obtained morphological data from 99 Microcebus individuals; we extracted DNA from tissue samples of 42 individuals and amplified two mitochondrial loci (cytb and cox2) commonly used for species identification. Our findings update the distribution of three species (Microcebus tavaratra, Microcebus arnholdi, and Microcebus mamiratra), including a major increase in the distribution area of M. arnholdi. We also report the discovery of a new Microcebus lineage genetically related to M. arnholdi. Several complementary approaches suggest that the newly identified Microcebus lineage might correspond to a new putative species, to be confirmed or rejected with additional data. In addition, morphological analyses showed (a) clear phenotypic differences between M. tavaratra and M. arnholdi, but no clear differences between the new Microcebus lineage and the sister species M. arnholdi; and (b) a significant correlation between climatic variables and morphology, suggesting a possible relationship between species identity, morphology, and environment. By integrating morphological, climatic, genetic, and spatial data of two northern Microcebus species, we show that the spatial distribution of forest‐dwelling species may be used as a proxy to reconstruct the past spatial changes in forest cover and vegetation type.  相似文献   

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We revise the 10 genera and 23 species of the tribe Phaeogenini (Ichneumonidae: Ichneumoninae) known to occur in the Afrotropical region. We describe the following 13 new taxa: Kibalus Rousse, van Noort & Diller, gen. n.; K. toro Rousse, van Noort & Diller, sp. n.; K. mubfs Rousse & van Noort, sp. n.; Arearia oxymoron Rousse & van Noort, sp. n.; Chauvinia nyanga Rousse & van Noort, sp. n.; Dicaelotus asantesana Rousse & van Noort, sp. n.; D. hoerikwaggoensis Rousse & van Noort, sp. n.; D. tablemountainensis Rousse & van Noort, sp. n.; Heterischnus mfongosi Rousse & van Noort, sp. n.; H. mkomazi Rousse & van Noort, sp. n.; Lusius flummox Rousse & van Noort, sp. n.; Tycherus amatola Rousse & van Noort, sp. n.; and T. nardousberg Rousse & van Noort, sp. n. New distribution records: Heterischnus africanus (Heinrich, 1936) from South Africa, Tanzania and Uganda; H. krausi Schönitzer, 1999 from Rwanda; Lusius tenuissimus (Heinrich, 1938) from Democratic Republic of Congo, Malawi, Nigeria, South Africa, and Zimbabwe. A doubtful record of Aethecerus foveolatus Gregor, 1940 from Sao Tome is additionaly reported in the appendix. We provide illustrated diagnoses and identification notes. Online interactive dichotomous and matrix Lucid keys to genera and species are available at http://www.waspweb.org.  相似文献   

10.
Free-floating Ulva L. biomass in the eutrophic brackish ‘Veerse Meer’ lagoon (southwest Netherlands) consists of four morphologically identified species: U. curvata (Kützing) De Toni, U. lactuca L., U. rigida C. Agardh and U. scandinavica Bliding. U. curvata could be recognized easily because of the characteristic central cavity in the holdfast of the attached plants, the arrangement of cells in rows and the single pyrenoid in each cell. U. rigida was distinguished by the thick thallus and the large number of pyrenoids. The Veerse Meer isolate, however, was slightly different from the isolate from the Oosterschelde estuary (the Netherlands). U. lactuca and U. scandinavica showed a high degree of overlap in thallus thickness and cell size, but U. scandinavica usually possessed more pyrenoids. However, doubts have frequently been expressed about the use of some morphological characters in Ulva taxonomy. To determine the validity of such characters in the identification of Ulva species, the morphological variation within and between morphological species was recorded and a molecular data set generated. To detect possible ecophysiological differences between species, optimum temperatures and salinities for growth were determined experimentally. The sequences of the nuclear ribosomal DNA internal transcribed spacer 2 (ITS2) and flanking regions of U. lactuca, U. rigida and U. scandinavica from the Veerse Meer were all identical, but differed from that of U. rigida from the Oosterschelde estuary. Ulva species from the Veerse Meer were most closely related to U. armoricana and U. rigida from Brittany (2.9% and 3.5% divergence respectively); the difference between U. rigida from the Veerse Meer and from the Oosterschelde estuary was 7.5%. Rooted trees, based on a comparison of these sequences with sequences of other Ulva and Enteromorpha species obtained from the literature, using Monostroma arcticum as outgroup, suggested that Ulva is paraphyletic with respect to Enteromorpha. The optimum temperature for growth of U. curvata was 25?°C; for all other species it was 10?°C. The optimum salinity for growth was 30?°C for all isolates. It is concluded that U. lactuca, U rigida and U. scandinavica from the Veerse Meer are all members of one highly polymorphic species.  相似文献   

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Igor M. Sokolov 《ZooKeys》2013,(352):51-92
One new genus and eight new species of anilline carabids are described from southern Mexico. The new genus, Zapotecanillus gen. n., is established for Z. oaxacanus (type species) sp. n., Z. nanus sp. n., Z. iviei sp. n., Z. ixtlanus sp. n., Z. montanus sp. n., and Z. kavanaughi sp. n. from the Sierra Madre de Oaxaca, Z. pecki sp. n. from the Sierra Madre del Sur, and Z. longinoi sp. n. from the Sierra Madre de Chiapas. A taxonomic key for all described species of Zapotecanillus and a cladistic analysis, based on morphological data, are provided. Morphological, behavioral and biogeographical aspects of the speciation in the genus obtained from the resulting cladogram are discussed.  相似文献   

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Evolutionary biologists have long commented on a seemingly universal "rule" of nature-that in large taxonomic assemblages from groups as diverse as bacteria, plants, insects, marine invertebrates, fish, reptiles, amphibians, birds, and mammals, there exists a frequency distribution of body sizes among species that is highly skewed to the right (positive skewness). This distribution reflects the strong inverse, or negative, relationship often noted between mean body size of taxa and the number of species they contain--i.e., the observation that small body size is often associated with high species diversity (speciosity). This is sometimes "explained" by recourse to the idea that smaller-bodied taxa are able to subdivide their environments more finely than larger-bodied taxa. With but few exceptions, the applicability of this "rule" to the Order Primates has not been studied in any detail. In this study I address the following questions of (paleo)anthropological interest: (1) How speciose is the Order Primates? (2) Does this biological "rule" characterize the Order Primates (at any taxonomic level) in any meaningful way? (3) Does the association between speciosity and body mass within the Order Primates provide any useful models for interpreting and/or predicting speciosity in the fossil primate record? Using phylogenetically independent contrasts methods, I conclude that the answers to those three questions are: (1) not very; (2) no; and (3) not particularly (with the possible exception of larger-bodied taxa).  相似文献   

15.
Hemiodus bimaculatus sp. nov., is described from tributaries of the Rio Juruena and Rio Teles Pires in the upper Rio Tapajós basin. The new species is diagnosed from most congeners, except Hemiodus jatuarana, by having a conspicuous circular or horizontally elongate dark blotch on the caudal peduncle (v. inconspicuous in H. iratapuru and absent in the other species). The new species differs from H. jatuarana by having a round midlateral spot on the flank (v. absent in H. jatuarana), 98–121 perforated scales in the lateral line (v. 66–72 in H. jatuarana), 23–28 scale series above and 14–19 below lateral line (v. 12–13 above and 6–7 below in H. jatuarana). Hemiodus bimaculatus is hypothesised to be related to species of the H. microlepis group, from which it also differs by having 11–25 epibranchial (v. 26–34 in H. argenteus, 29–39 in H. microlepis, 21–42 in H. orthonops and 27–35 in H. parnaguae) and 18–31 ceratobranchial (v. 38–50 in H. argenteus, 43–58 in H. microlepis, 32–52 in H. orthonops and 34–48 in H. parnaguae) gill rakers in the first arch.  相似文献   

16.
Varicharax nigrolineatus, a new genus and species of stevardiine fish, is described from the Río Amazonas basin, Peru, based on a comprehensive phylogenetic comparison with other characids. Two data sets (A: combined morphological and molecular matrix, 474 species and 6,653 characters; B: morphological matrix, 216 species and 524 characters) were used to estimate the phylogenetic relationships of the new genus. Morphological and molecular data from these data sets were taken from two previously published matrices on characids. Varicharax nigrolineatus is phylogenetically diagnosed by 18 autapomorphies in total (from both data sets), which are related to different anatomical characteristics of the neurocranium, body, and fins. Furthermore, V. nigrolineatus can be easily differentiated from all characids (except Acrobrycon in part) by the following combination of characters: the presence of a hypertrophied caudal-fin squamation on the lower caudal-fin lobe forming a remarkable pouch-like structure, consisting of multiple series of large adjacent scales (being almost similar or slightly more pronounced in males than in females), the presence of caudal-fin bony hooks on the lower lobe in adult males, complete lateral line, and a dark mid-lateral stripe that extends from the posterior border of the head to caudal peduncle. In the resulting topologies from both data sets, the phylogenetic placement of V. nigrolineatus was well supported within Stevardiinae. Additionally, V. nigrolineatus was resolved within the tribe Stevardiini as sister group of a clade formed by Chrysobrycon + Pseudocorynopoma and Corynopoma + Gephyrocharax in the final hypothesis from the combined data set, whereas in the final topology from the morphological data set, V. nigrolineatus was placed as sister group of a clade comprised of Acrobrycon and the Stevardiini without Argopleura.  相似文献   

17.
Semi-natural grasslands are some of the most threatened habitats on the planet, due to the abandonment of small-scale farming and its replacement with intensive agriculture. The fragmented landscape of today has created dispersal limitation that makes improbable the natural dispersal of target species into the remaining patches of grassland. This paper reviews the current status of species introduction into semi-natural grasslands, and summarises the results of published literature in this field. Our review shows that restoration through species introduction is an effective method of establishing dispersal limited species. However, the field of species introduction in restoration ecology has yet to make use of the value that Functional Diversity can add to restoration. No single study in our search has followed up species introduction by measuring any of the currently available indices of functional diversity. This approach is necessary to gain knowledge on what traits are likely to be sorted out in species introduction cases in various environments.  相似文献   

18.
Understanding the dynamics of the Late Quaternary Caribbean mammal extinction event is complicated by continuing uncertainty over the taxonomic status of many species. Hispaniola is one of the few Caribbean islands to retain native non-volant mammals; however, there has been little consensus over past or present levels of diversity in Hispaniolan hutias (Capromyidae: Plagiodontinae). Craniodental measurement data from modern hutia specimens, previously classified as both Plagiodontia aedium and P. hylaeum, display morphological differences between Hispaniola's northern and southern palaeo-islands using MANOVA and PCA. Although attempts to amplify mitochondrial DNA from the holotype of Paedium were unsuccessful, this specimen is morphometrically associated with southern palaeo-island specimens. The mandibular size distribution of recent Plagiodontia specimens is unimodal, but the Late Quaternary mandibular size distribution is multimodal and displays much broader measurement spread, representing multiple extinct species. Finite Mixture Analysis was used to assess the best fit of different taxonomic hypotheses to the fossil mandibular size distribution. All retained FMA models include living hutias and P. spelaeum as distinct taxa; PCA further demonstrates that levels of morphological variation between modern hutia populations are lower than levels between living hutias and P. spelaeum, so that living hutias are interpreted as the single species P. aedium. Taxonomic differentiation for larger-bodied hutias is less well defined, but most retained models show only one larger species, for which the only available name is P. velozi. ‘Plagiodontiaaraeum is morphologically distinct from other species and is reassigned to Hyperplagiodontia. Hispaniola's plagiodontine fauna has lost its largest and smallest representatives; similar trends of body size selectivity in extinction risk are shown more widely across the Caribbean mammal fauna, possibly due to different regional anthropogenic threats (invasive mammals, hunting) affecting small-bodied and large-bodied mammals during the recent past. This apparent pattern of extinction selectivity is named the ‘Goldilocks Hypothesis’.  相似文献   

19.
A new species in the family Pyralidae is described: Megasis kocaki sp. n., of which the adult, head and the male genitalia are illustrated. The new species is compared with the closely allied Megasis hyrcanella Ragonot, 1893.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:0136DD7F-0E91-4114-9B3B-A42E6114A985  相似文献   


20.
The research was conducted in two natural forest communities: Potentillo albae-Quercetum (oak forest) which allows much light to reach the forest floor and Tilio-Carpinetum typicum (hornbeam forest) which shades the herb layer heavily. The seed banks were estimated from numbers of seedlings emerging from soil samples over one growing season.(1) Our results confirm the hypothesis that persistent seed banks are mainly formed by species with high light requirements. Of the species found predominantly in the seed bank and absent from the herb layer or occurring there very rarely in both communities 83% of species and 70% of seedlings were strongly light-demanding (Ellenberg's light index 6–9). However, the results do not support the hypothesis that seed banks in natural deciduous forest communities are small, poor in species and do not reflect the species composition of herb layer.(2) The seed banks of both communities were rich in species and relatively large. Species richness in the oak forest turned out to be higher than in the hornbeam forest (51 vs 45 species/2.4 m2), but size was smaller (2659 vs 5789 seedlings/2.4 m2). In the oak forest the most abundant species in the seed bank was Galium boreale, but it constituted only 19% of the total number of seedlings, whereas in the hornbearn forest the dominant species, Urtica dioica, constituted 57% of the total.(3) In each community the species composition of the seed bank and the herb layer was very similar (>70%).(4) The seed bank was more diverse in the oak forest than in the hornbeam forest (H 2.34 vs 1.68).(5) The seed banks of both communities differed in the contribution of species with varied light requirements; in the sunny oak forest species with high light requirements dominated, whereas in the shady hornbeam forest both strongly and moderately light-demanding species had similar contributions.Nomenclature: Follows Ehrendorfer (1973) and Matuszkiewicz (1981).  相似文献   

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