18S ribosomal RNA gene sequences of Cochliopodium (Himatismenida) and the phylogeny of Amoebozoa

Cochliopodium is a very distinctive genus of discoid amoebae covered by a dorsal tectum of carbohydrate microscales. Its phylogenetic position is unclear, since although sharing many features with naked "gymnamoebae", the tectum sets it apart. We sequenced 18S ribosomal RNA genes from three Cochliopodium species (minus, spiniferum and Cochliopodium sp., a new species resembling C. minutum). Phylogenetic analysis shows Cochliopodium as robustly holophyletic and within Amoebozoa, in full accord with morphological data. Cochliopodium is always one of the basal branches within Amoebozoa but its precise position is unstable. In Bayesian analysis it is sister to holophyletic Glycostylida, but distance trees mostly place it between Dermamoeba and a possibly artifactual long-branch cluster including Thecamoeba. These positions are poorly supported and basal amoebozoan branching ill-resolved, making it unclear whether Discosea (Glycostylida, Himatismenida, Dermamoebida) is holophyletic; however, Thecamoeba seems not specifically related to Dermamoeba. We also sequenced the small-subunit rRNA gene of Vannella persistens, which constantly grouped with other Vannella species, and two Hartmannella strains. Our trees suggest that Vexilliferidae, Variosea and Hartmannella are polyphyletic, confirming the existence of two very distinct Hartmannella clades: that comprising H. cantabrigiensis and another divergent species is sister to Glaeseria, whilst Hartmannella vermiformis branches more deeply.     

Cochliopodium arabianum n. sp. (Amorphea,Amoebozoa)

A new species of Cochliopodium isolated from freshwater at Arabia Lake in Lithonia, GA, USA is described based on light microscopic morphology, fine structure, and molecular genetic evidence. Cochliopodium arabianum n. sp., previously labeled as “isolate Con1” in prior publications, has been shown to group within the genus Cochliopodium in our molecular phylogenetic analysis. Light microscopy and fine structure evidence indicates the new isolate not only shares characters of the genus but also unique distinctive features. Cochliopodium arabianum n. sp. is typically round when stationary; or oval to sometimes broadly flabellate or triangular in shape during locomotion, with average length of 35 μm and breadth of 51 μm. Fine structure evidence indicates C. arabianum n. sp. has tower‐like scales, lacking a terminal spine, sharing high similarity with its closest relative C. actinophorum. However, the scales of C. arabianum n. sp. are unique in height and the breadth of the base plate. Both morphological and molecular data, including SSU‐rDNA and COI, indicate that this new species falls in a clade sufficiently different from other species to suggest that it is a valid new species.     

Cochliopodium gallicum n. sp. (Himatismenida), an amoeba bearing unique scales, from cyanobacterial mats in the Camargue (France)

Cochliopodium gallicum n. sp., isolated from cyanobacterial mats in the Camargue (France) is the smallest marine species of Cochliopodium to date. Its unusual tectum consists of flat plate-shaped scales with honeycomb-like centres, underlain by a layer of filamentous structures connected to each other in the basal and apical parts. The tectum is very fine and can be easily lost under inappropriate EM fixation. In its light-microscopical features, this species resembles Ovalopodium carrikeri Sawyer, 1980, a himatismenid that is believed to possess a scaleless, fuzzy or hairy "glycocalyx". We suggest that O. carrikeri might have been a similar species that lost scales under fixation. Our finding makes desirable a re-investigation of the genus Ovalopodium.     

A New Freshwater Amoeba: Cochliopodium pentatrifurcatum n. sp. (Amoebozoa,Amorphea)

Cochliopodium pentatrifurcatum n. sp. (ATCC^© 30935^TM) is described based on light microscopic morphology, fine structure, and molecular genetic evidence. Cochliopodium pentatrifurcatum n. sp. (length ~ 25 μm) is characterized by surface microscales (0.3 μm tall) containing a circular porous base (~ 0.6 μm diam.) with a thin peripheral rim. Five radially arranged feet, emanating from the base, support a short central column terminating apically as a funnel‐shaped collar (~ 0.5 μm diam.) composed of five radial, trifurcate rays extending from the center toward a thin peripheral rim. The central spine is 0.5–0.6 μm long. The comparative morphologies and combined molecular genetic evidence, SSU‐rDNA and COI, indicate that the new species falls in a clade sufficiently different from other species to suggest that it is a valid new species.     

Three New Freshwater Cochliopodium Species (Himatismenida,Amoebozoa) from the Southeastern United States

Cochliopodium is a lens‐shaped genus of Amoebozoa characterized by a flexible layer of microscopic dorsal scales. Recent taxonomic and molecular studies reported cryptic diversity in this group and suggested that the often‐used scale morphology is not a reliable character for species delineation in the genus. Here, we described three freshwater Cochliopodium spp. from the southeastern United States based on morphological, immunocytochemistry (ICC), and molecular data. A maximum‐likelihood phylogenetic analysis and pairwise comparison of COI sequences of Cochliopodium species showed that each of these monoclonal cultures were genetically distinct from each other and any described species with molecular data. Two of the new isolates, “crystal UK‐YT2” (Cochliopodium crystalli n. sp.) and “crystal‐like UK‐YT3” (C. jaguari n. sp.), formed a clade with C. larifeili, which all share a prominent microtubule organizing center (MTOC) and have cubical‐shaped crystals. The “Marrs Spring UK‐YT4” isolate, C. marrii n. sp., was 100% identical to “Cochliopodium sp. SG‐2014 KJ569724 .” These sequences formed a clade with C. actinophorum and C. arabianum. While the new isolates can be separated morphologically, most of the taxonomic features used in the group show plasticity; therefore, Cochliopodium species can only be reliably identified with the help of molecular data.     

Two new species of Pythium, P. schmitthenneri and P. selbyi pathogens of corn and soybean in Ohio

Two new species of Pythium, pathogens of corn and soybean in Ohio, are described. Pythium schmitthenneri sp. nov. and Pythium selbyi sp. nov. both have morphological and sequence characteristics that place them in clade E1 of the genus Pythium. Morphology and sequence analysis of the ITS1-5.8S-ITS2 regions of these species were different from previously described species. The ITS region of Pythium schmitthenneri was 99.9% similar to P. acrogynum and 99.8% similar to P. hypogynum. All three species are characterized by globose to limoniform sporangia and plerotic oospores. Pythium schmitthenneri has mostly diclinous antheridia, compared to the strictly hypogynous antheridia of P. acrogynum and P. hypogynum. The temperature for growth of P. schmitthenneri is below 4 C to 32 C, and optimum growth is 18-25 C compared to 31-34 C for P. hypogynum. The ITS region of P. selbyi was 97.1% similar to P. longandrum and 97.5% similar to P. longisporangium. All three species are characterized by globose sporangia, mostly plerotic oospores, with one to two oospores per oogonium, and hypogynous or monoclinous antheridia. The temperature for growth of P. selbyi is below 4 to 32 C, with an optimum 18-25 C. These new species were widely dispersed throughout the soybean- and corn-producing regions in Ohio, making their characterization critical for managing the Pythium complex that causes seedling and root-rot disease in Ohio soybean and corn fields.     

Three new species of Centella series Glabratae (Apiaceae)

Three new species of Centella series Glabratae are described in this paper: C. brachycarpa, C. dolichocarpa and C. pilosa. These species are similar to C. difformis , and in order to clarify species limits the latter is also described and illustrated. The fruit shape and the bulging commissure of the new species show that the sectional limits of the series Glabratae will have to be revised to include C. difformis and related species, previously associated with the series Montanae.     

广义虫草属二新记录种

【背景】广义虫草属是一类重要的虫生真菌资源。【目的】对我国西南地区虫生真菌及其相关真菌资源进行调查。【方法】在贵州省习水县和花溪区进行标本采集,采用含双抗的PDA培养基分离目的菌株;基于形态学特征和ITS rDNA序列系统发育分析相结合的方法进行菌株鉴定。【结果】从采集到的标本中分离获得5个菌株,菌株GY1113、GY90809和GY90810在形态特征上与马拉维白僵菌模式菌株非常相近;系统发育树中二者以高持率(ML/BI为99/1)聚成一个分支。菌株A1997在形态特征上与鳞翅目虫草模式菌株非常吻合;系统发育树中二者以较高支持率(ML/BI为78/0.95)聚成一个分支。菌株A1972在形态上与苏格兰白僵菌模式菌株的形态特征非常相近;系统发育树中二者以高支持率(ML/BI为99/1)聚成一个分支。因此分别鉴定为马拉维白僵菌、鳞翅目虫草及苏格兰白僵菌。【结论】马拉维白僵菌和鳞翅目虫草为中国新记录种。     

Morphological,small subunit rRNA,and physiological characterization of Trimyema minutum (Kahl, 1931), an anaerobic ciliate from submarine hydrothermal vents growing from 28 degrees C to 52 degrees C

A thermophilic strain of Trimyema minutum was isolated from the hydrothermally heated sea floor at Vulcano Island (Italy) and cultivated monoxenically on Marinobacter sp. and Methanococcus thermolithotrophicus. It can be propagated strictly anaerobically and is sensitive to oxygen: if exposed to air at 48 degrees C all cells die within 60 min. It grows from 0.45-7.2% (w/v) salt and at pH 6.0-8.0. The isolate is the most extreme thermophilic ciliate which ever has been cultivated, exhibiting an optimal growth temperature of 48 degrees C (doubling time 6 h). Growth occurs between 28 degrees C and 52 degrees C. Trimyema minutum is redescribed using live observation and silver impregnation. Its morphology and the small subunit ribosomal RNA sequence is distinctly different from that of T. compressum, but morphology is highly similar to that of T. shoalsia Nerad et al. 1995, which is thus probably a junior synonym of T. minutum. To stabilize the bewildering species taxonomy in Trimyema, we suggest to recognize our population as a neotype of T. minutum.     

Three new species of Centella series Montanae

Three new species of Centella are described: C. cryptocarpa, C. gymnocarpa and C. longifolia . These species are similar to C. montana and in order to clarify species limits, the latter is also described and illustrated. The concept of the series Montanae is broadened to include all species with transversely oblong fruit of which the commissure is narrower than the rest of the fruit.     

紫堇科二新种

该文描述了紫堇科二新种:(1)自云南省发现的紫堇科紫堇属一新种,宽鳞紫堇。此新种与波密紫堇相近似,与后者的区别在于本新种的根状茎鳞片半透明,具三条脉,茎无叶,外花瓣无鸡冠状突起,雄蕊束具2花药,花丝条形,无脉,子房宽条形。(2)自黑龙江省发现的紫堇科紫堇属一新种,鹤岗延胡索。此种与新疆元胡相似,但本种叶的小叶多在顶端,具1~5牙齿,花序苞片有3~5小裂片,上花瓣及其瓣片和距均较小,蜜腺呈狭卵球形,弯曲,顶端尖锐而与新疆元胡相区别。     

A new western Mediterranean species of Cuscuta (Convolvulaceae) confirms the presence of holocentric chromosomes in subgenus Cuscuta

Cuscuta nivea , a new western Mediterranean species of Cuscuta L. subgenus Cuscuta (Convolvulaceae) is described and illustrated for plants traditionally included in C. planiflora Ten. and sometimes recognized as C. planiflora var. algeriana Yunck., or the illegitimate C. cuspidata Pomel. The morphological, cytological and ecological features that allow it to be distinguished from the morphologically most similar plants, described as C. planiflora var. papillosa Engelm., are exposed. The chromosome numbers 2 n = 18 and 2 n = 20 are found for the new species and 2 n = 34 for the papillate forms of C. planiflora Ten. The presence of holocentric chromosomes is recorded, which confirms this type of chromosome as a synapomorphy for Cuscuta subgenus Cuscuta .     

Corynopuntia halophila (Cactaceae), a new species from Coahuila,Mexico

A new halophilous–gypsicolous species of Corynopuntia, C. halophila (Cactaceae), is described and illustrated from the state of Coahuila, north-eastern Mexico. It is morphologically similar to the diploid Corynopuntia moelleri, but it differs by some traits, such as body size and some unusual morphological features which are here reported for the first time; there are also ecological and karyological differences, as the latter study revealed that C. halophila is a polyploid with 2n = 44 chromosomes. Diagnostic morphological characters from similar taxa are discussed and arranged in a taxonomic key. Knowledge of the species ecology, biogeography, demography and conservation status is also provided.     

A new species of Propliopithecus from the Fayum, Egypt

Propliopithecus ankeli is described as a new species of hominoid from the early Oligocene of Egypt. The new species occurs at a stratigraphic level 80 m below quarries yielding P. chirobates and Aegyptopithecus zeuxis. P. ankeli differs from other species of the genus in its large size, relatively robust canines, larger and proportionally broader premolars, and M1 that has as great or greater mesiodistal length than M2. Thus, P. ankeli is characterized by increased relative size and robustness of the antemolar dentition, which contrasts with the pattern observed in the Fayum's other large hominoid, A. zeuxis. P. ankeli probably represents a lineage not ancestral to other Fayum hominoids. Discovery of this new species emphasizes the diversity of anthropoid primates that had already evolved by the early Oligocene.