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1.
ABSTRACT

Phaseolus vulgaris L. seed germination and seedling root anatomy were investigated on a slowly rotating clinostat in 1g. Clinostat rotating seeds were oriented as follows: the first group with the longer axis parallel to the rotation pole (horizontal), the other with the longer axis normal to the rotation pole with due attention to the position of the root apex primordium in the dry seeds (vertical). Germination time, percent germination and curvature of developing roots were monitored. Furthermore, the anatomy of the root apex was quantitatively analysed. Seeds placed on the clinostat germinated earlier than controls, and columella cells of roots developed while rotating lost the strict polarity with the nucleus positioned near the proximal periclinal cell wall and amyloplasts sedimented on the distal periclinal wall. Irrespective of seed orientation on the rotation axis, loss of cell polarity occurred as well as a decrease in starch content, modification in cell size, and damage to statocytes whose walls appeared partially digested. Cell size in the elongation zone was also larger in roots rotating on the clinostat than in controls, both in vertically and horizontally placed specimens. Our results demonstrate that prolonged rotation has an effect on the statocyte that continuously perceives gravity from ever-changing directions, although this effect is irrespective of seed position on the rotating axis in P. vulgaris.  相似文献   

2.
The species Anomala aereiventris n. sp., A. aspersa n. sp., A. atrivillosa n. sp., A. clarivillosa n. sp., A. contusa n. sp., A. eusticta n. sp., A. hiata n. sp., A. latifalculata n. sp., A. leopardina n. sp., A. levicollis n. sp., A. longisacculata n. sp., A. m-fuscum n. sp., A. perspicax n. sp., A. piccolina n. sp., A. globulata n. sp., A. stillaticia n. sp., A. subridens n. sp., A. subusta n. sp., A. tenoriensis n. sp., A. tuberculata n. sp. and A. vallisneria n. sp. from Costa Rica are described. These species and A. polygona Bates 1888, A. trapezifera Bates 1888 and A. vulcanicola Ohaus 1897 are placed in a new species-group, named after A. trapezifera, whose diagnosis is provided. Their distribution patterns are discussed.  相似文献   

3.
Four new species of Alaus Eschscholtz, 1829 are described: A. cinnamomeus n. sp., A. latlpennls n. sp., A. serlceus n. sp. and A. thoracopunctatus n. sp. Three species removed from Chalcolepldlus Eschscholtz, 1829, are transferred to this genus: A. allcll (Pjatakowa, 1941) n. comb., A. haroldl (Candèze, 1878) n.comb. and A. unlcus (Fleutiaux, 1910) n. comb. The characters of external morphology of these seven species and male and female genitalia, when available, are described and illustrated. An identification key for all species of the genus is included: A. allcll (Pjatakowa, 1941) n. comb., A. calcarlpllosus Casari, 1996, A. cinnamomeus n. sp., A. haroldl (Candèze, 1878) n. comb., A. latlpennls n. sp., A. lusclosus (Hope, 1832), A. melanops Leconte, 1863, A. myops (Fabricius, 1801), A. nobllls Sallé, 1855, A. oculatus (Linnaeus, 1758), A. patrlclus (Candèze, 1857), A. plebejus Candèze, 1874, A. serlceus n. sp., A. thoracopunctatus n. sp., A. tricolor (Olivier, 1790), A. unlcus (Fleutiaux, 1910) n. comb., A. veracruzanus Casari, 1996 and A. zunianus Casey, 1893.  相似文献   

4.
Summary. The Adoretini of the Malagasy endemic genus Adorodocia Brenske 1893 is revised. Fourteen new species and one new subspecies are described and compared with their most closely related species: A. constricta n. sp., A. cuccodoroi n. sp., A. flava n. sp., A. liliae n. sp., A. marginata n. sp., A. peyrierasi n. sp., A. pseudoconstricta n. sp., A. pseudoflava n. sp., A. pseudostrigata n. sp., A. recta n. sp., A. robusta n. sp., A. sogai n. sp., A. vadoni n. sp., A. viettei n. sp. and A. vittaticollis flavipes n. ssp. The synonymy between Adoretus strigatus Waterhouse 1878, and Pseudadorodocia aenigma Arrow 1901, is confirmed. Thus, based on the results of this study, the genus Adorodocia includes 16 species, and one of them is represented by two subspecies. Diagnostic characters to separate the species in the genus deal mostly with the shape of parameres, color of body and legs, shape of pronotum and female eighth tergite, setation of pronotum and elytra. Key to species, diagnoses and distribution for each species are provided. Endophallus and female genitalia are illustrated for the first time for this genus.  相似文献   

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7.
This paper describes Ascogrammitis, a new genus of grammitid ferns formerly combined under Terpsichore. Seventeen species are recognized, including five new ones: A. clavigera, A. colombiensis, A. loxensis, A. oxapampensis, and A. tungurahuae. New combinations are made for A. alan-smithii, A. anfractuosa, A. angustipes, A. athyrioides, A. clathrata, A. cuencana, A. david-smithii, A. dilatata, A. nana, A. pichinchae, A. pichinchensis, A. stuebelii, and a lectotype is chosen for Polypodium induens. A key is provided to distinguish the species, and illustrations are provided for 12 species. The genus occurs primarily in neotropical cloud forests, with the greatest diversity in the Andes. Ascogrammitis is one of two monophyletic groups of grammitid ferns that are consistently associated with Acrospermum, an epibiotic bitunicate ascomycete that produces black clavate fruiting bodies.  相似文献   

8.

A new ichnospecies of Arthrophycus Hall 1852, A. minimus , is described from Upper Cambrian-Lower Tremadocian, shallow-marine strata of northwest Argentina. This new ichnospecies consists of small, long, regularly annulated hypichnial elements displaying subcircular to squarish cross-section and a ventral median groove. Side branches are occasionally present, but palmate, fan-like structures and scribbling patterns are absent. We adopt a relatively narrow diagnosis of Arthrophycus , suggesting that roughly annulated, cylindrical structures should not be included in this ichnogenus, unless other diagnostic features (i.e., squarish cross-section, median groove, zipper-like annulations) are also present. Arthrophycus is a common ichnotaxon in Ordovician-Silurian shallow-marine siliciclastic environments. Post-Paleozoic occurrences are removed from Arthrophycus . Arthrophycus has been proposed as a biostratigraphic index fossil in Ordovician-Silurian rocks. The presence of A. minimus in the Santa Rosita Formation of northwest Argentina indicates that Arthrophycus ranges at least from the Upper Cambrian-Lower Tremadocian with probable representatives in the Lower Cambrian and, therefore, its biostratigraphic utility is extended. Arthrophycus minimus represents the first Cambrian occurrence exhibiting not only fine, diagnostic morphologic features, but also the classical Arthrophycus behavioral pattern in dense monoichnospecific assemblages. The exploratory behavioral pattern displayed by A. minimus is simpler than that of the younger ichnospecies, particularly A. brogniartii, A. alleghaniensis, and A. lateralis . This is consistent with the basal position of A. minimus within the arthrophycid lineage.  相似文献   

9.
10.
Twelve morphologically similar species of Acrapex Hampson 1894, (Lepidoptera, Noctuidae, Noctuinae, Apameini, Sesamiina), from Western, Central and Eastern Africa are reviewed. Eight of these species are new to science and are described: Acrapex akunamatata n. sp. and A. incrassata n. sp. from Kenya; A. gracilis n. sp., A. iringa n. sp., A. lukumbura n. sp. and A. rungwe n. sp. from Tanzania; A. soyema n. sp. from Ethiopia; and A. zoutoi n. sp. from Benin. All 12 species belong to a species complex that we hereby define as the Acrapex apicestriata group. Host-plants for three of the new species are recorded: Setaria incrassata (Hochst.) Hack. for Acrapex incrassata; Cymbopogon pospishilii (K. Schum.) C.E. Hubb. for A. rungwe; and Andropogon perligulatus Stapf. for A. zoutoi. We also conducted molecular phylogenetic analyses (using maximum likelihood and Bayesian inference) on a six gene multimarker molecular dataset (four mitochondrial and two nuclear gene fragments; 4581 nucleotides in length) consisting of 15 Acrapex species (including seven species from the apicestriata group) and four outgroups species from the subtribe Sesamiina (from genera Busseola Thurau 1904, Sciomesa Tams & Bowden 1953, Pirateolea Moyal, Le Ru, Conlong, Cugala, Defabachew, Matama-Kauma, Pallangyo & Van den Berg 2010 and Sesamia Boisduval & Guenée 1852). Both maximum likelihood and Bayesian inference analyses yield a similar and well-supported topology, which supports the monophyly of the apicestriata group.  相似文献   

11.
Cariniana as previously circumscribed is a genus of 16 species restricted to neotropical forest habitats on well-drained sites. A phylogenetic analysis of the genus based on 33 morphological and anatomical characters was undertaken. The results show that Cariniana consists of two clades: the Allantoma/Cariniana decandra clade includes Allantoma lineata and seven species of actinomorphic-flowered Cariniana and is characterized by 5-merous flowers, carnose petals, incurved petal apex, scarcely lobed calyces, eucamptodromous secondary veins, dichotomizing venation, and poorly developed areolation; the C. legalis clade is made up of nine species and is characterized by an obliquely zygomorphic androecium, reticulate tertiary venation, and anomocytic stomata. The actinomorphic-flowered Cariniana are more closely related to the monotypic Allantoma lineata than they are to the species of the C. legalis clade. In order to reflect these relationships, Cariniana is divided into two genera: species in the C. legalis clade, which includes the generic type C. legalis, remain as Cariniana while species of Cariniana in the Allantoma/Cariniana decandra clade are transferred to Allantoma. The following new combinations are proposed: Allantoma decandra, A. integrifolia, A. kuhlmannii, A. pluriflora (a nomen novum for Cariniana multiflora because Allantoma multiflora is a synonym of Couratari multiflora), A. pachyantha, A. pauciramosa, and A. uaupensis.  相似文献   

12.
Three new species of the genus Aeschnosoma are briefly described and illustrated. A. pseudoforcipula n. sp. and A. heliophila n. sp., both from the Brazilian Central Plateau are respectively related to the two Amazonian species A. forcipula Hagen in Selys 1871, and A. auripennis Geijskes 1970. A. louissiriusi n. sp. from Northern Brazil is not closely related to any known species. Based on larval and adult derived characters, the genus Aeschnosoma appears closely related to the Australian genus Pentathemis Karsch 1890, and also to the Madagascan genus Libellulosoma Martin 1907. The clade Aeschnosomata nov. is erected to receive the three genera. Some putative plesiomorphies would place this clade sister group of the remaining Corduliidae s.str.  相似文献   

13.
The following new species of Apioninae weevils (Coleoptera: Brentidae) are described from Dominican amber. Toxorhynchus leptorhinusn. sp., Toxorhynchus robustusn. sp., Toxorhynchus amphioculusn. sp., Toxorhynchus atriartusn. sp., Toxorhynchusatriantenusn. sp. and Toxorhynchus hispaniolicusn. sp. are members of the Toxorhynchus decoloratum species group. Toxorhynchus microsomusn. sp., Toxorhynchus stenelytrusn. sp., Toxorhynchus dominicanusn. sp., Toxorhynchus convexusn. sp., Toxorhynchus fuscocorpusn. sp., Toxorhynchus hispidulusn. sp. and Toxorhynchus convexoculusn. sp. are members of the Toxorhynchus sordidum species group. A new subtribe, Stenapiina n. subtribe of the tribe Toxorhynchini, is erected. New species Apionion homochrononn. sp.,Apionion kallimosumn. sp.,Apionion formoculusn. sp. and Stenapion levigatumn. sp. are described. The dominate species of the genus Toxorhynchus and especially those in the Toxorhynchus decoloratum and Toxorhynchus sordidum species groups in Dominican amber are now absent from the West Indies. A systematic update of extant representatives of Apioninae in Hispaniola is provided.http://www.zoobank.org/urn:lsid:zoobank.org:pub:2D4A59DB-E804-4B45-8773-C027A8AD5A02  相似文献   

14.
A summary is presented of all Peruvian species of scaly tree ferns (Cyatheaceae). A total of 83 species is native to Peru (Sphaeropteris 1 sp., Alsophila sect. Alsophila 9 spp., Alsophila sect. Gymnosphaera 1 sp., Cyathea 72 spp.), with 13 endemic species in Cyathea and one in Alsophila. The following new species are described and illustrated: Alsophila gastonyi, Cyathea chontilla, C. nephele, C. polliculi, and C. praetermissa. The genera Cnemidaria and Trichipteris are no longer recognized and merged in Cyathea. Necessary combinations are made for Cyathea alatissima, C. nervosa, and C. uleana. Cyathea serpens is presented in detail and its relationship is discussed. An artificial key to the Peruvian species of Cyatheaceae is provided.  相似文献   

15.
W. John Hayden 《Brittonia》1990,42(4):260-270
Lectotypes are designated forAmanoa caribaea Krug & Urban andA. guianensis Aublet; presumed syntypes of the latter taxon are shown to be heterogeneous by inclusion of a previously unrecognized species. Four new species ofAmanoa are described:A. congesta from French Guiana and northeastern Brazil;A. gracillima from Manaus, Brazil;A. nanayensis from Amazonian Peru and adjacent Colombia and Brazil; andA neglecta from French Guiana and Surinam.Amanoa sinuosa is proposed as a new name for the later homonymA. robusta Leal. A key to the 13 neotropical species is presented.  相似文献   

16.
A taxonomic revision of the genus Aneorhachis Kleine 1923 (Coleoptera: Brentidae) and a phylogenetic analysis of species belonging to this genus are carried out. The genus Ipsopisthius Kabakov 2001 is synonymised with Aneorhachis, and two new combinations are proposed: Aneorhachis hirta (Kabakov 2001), n. comb. and A. incerta (Kleine 1935), n. comb. Higonius nitens Goossens 2008 is synonymized with A. incerta. One new species is described from New Guinea, A. papuana n. sp. All the species are redescribed and type-specimens are illustrated; an identification key is proposed. A maximum parsimony analysis is provided on the base of 23 characters from adult morphology. This analysis confirms the monophyly of the genus and seems to show that Aneorhachis originated on continental Asia and then spread out eastward to colonize Pacific islands.  相似文献   

17.
The MAT A locus of Yarrowia lipolytica, which was on the basis of its ability to induce sporulation in a diploid B/B strain, represses the mating capacity of this strain. The gene functions required for induction of sporulation and repression of conjugation could be separated by subcloning. Sequence analysis revealed two ORFs in the MAT A locus. One of them (MAT A1) codes for a protein of 119 amino acids which is required to induce sporulation. The other (MAT A2) codes for a protein of 291 amino acids that is able to repress conjugation. Both genes are oriented divergently from a central promoter region, which possesses putative TATA and CAAT boxes for both genes. The product of MAT A1 shows no homology to any known protein and seems to represent a new class of mating-type genes. MAT A2 contains a HMG box with homology to other mating-type genes. Both MAT A1 and MAT A2 are mating-type specific. In cells of both mating types, the regions flanking the MAT A locus contain sequences with homology to either S. cerevisiae SLA2 and ORF YBB9, respectively. From hybridization and subcloning data we estimate that the MAT A region is approximately 2 kb long and is present only once in the genome. Received: 25 January 1999 / Accepted: 16 April 1999  相似文献   

18.
A synopsis of the genus Cohniella is presented with nomenclatural updates with a discusion of diagnostic features and biogeographical data. Thirteen species and one natural hybrid are recognized. Two new species, Cohniella pendula and Cohniella biorbicularis, are described and illustrated. The following four new combinations are proposed: Cohniella binotii, Cohniella brachyphylla, Cohniella cepula, and Cohniella longifolia. Lectotypes are selected for Oncidium subulifolium, Oncidium helicanthum, Oncidium humboldtii, Oncidium jonesianum var. phaeanthum, Oncidium cepula, and Oncidium wittii. We also propose an amended lectotype for Epidendrum cebolleta and several epitypifications and new synonyms. A key to the genera of the Trichocentrum complex is presented (Appendix) as well as keys to the species of Cohniella.  相似文献   

19.
A simplified model is presented of the dynamics of excitatory and inhibitory neurons in the cerebral cortex. A key feature of the model is that neurons may cease to fire when strongly depolarized (spike inactivation). Computer simulations for different parameters reveal five classes of solutons: a) steady states in which neither excitatory nor inhibitory cells are active, b) steady states in which one or both types of cells fire repetitively, c) states in which one type of cell fluctuates rapidly between bursts of action potentials and inactivity due to strong depolarization, d) rhythmic activity in which both types of cells fire in unison followed by a period of spike inactivation and e) states similar to d but in which the inhibitory cells never produce action potentials. Solutions b, c, d, and e qualitatively resemble the different firing patterns observed during experimental seizures. It is shown that changes in those parameters that are functions of potassium concentration can induce changes in the type of solution. It is therefore proposed that the increase in extracellular potassium concentration during seizures may be responsible for the progressive changes observed in firing patterns and particularly for the transition from tonic to clonic patterns. A method is also outlined for testing the predictions of the model.  相似文献   

20.
Aristolochia dalyi, from western Peruvian and Brazilian Amazonia, andA. bahiensis, from Bahia, Brazil, are described and illustrated. The species belong toAristolochia ser.Thyrsicae andA. ser.Hexandrae subser.Anthocaulicae, respectively. A key to the eight western Amazonian species of the seriesThyrsicae is presented.Aristolochia dalyi closely resemblesA. silvatica Barb. Rodr. from the Río Negro basin, andA. bahiensis—the first cauliflorous species ofAristolochia known from the Mata Atlantica—is similar toA. guentheri O. C. Schmidt andA. klugii O. C. Schmidt, from the Western Amazon basin. Characters based primarily on the perianth shape, along with some vegetative features, are used to distinguish the two newly described species from their close relatives.
Resumen   Aristolochia dalyi, del occidente de la amazonía peruana y brasilera, yA. bahiensis, del estado de Acre, en Brasil, son descritas e ilustradas. Las especies pertenecen aAristolochia ser.Thyrsicae yA. ser.Hexandrae subser.Anthocaulicae respectivamente.Aristolochia dalyi es incluída en una clave para diferenciarla de las especies de la serieThyrsicae presentes en la Amazonía occidental, y resulta ser similar aA. silvatica Barb. Rodr, propia de la cuenca del río Negro; por su parte,A. bahiensis, hasta ahora la única especie deAristolochia cauliflora hallada en la Mata Atlántica, es similar aA. guentheri O. C. Schmidt yA. klugii O. C. Schmidt, propias del occidente de la cuenca amazónica. Los caracteres diagnósticos de las nuevas especies se basan principlalmente en la forma del perianto, aunque algunas diferencias vegetativas son también reconocidas.
  相似文献   

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