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1.
Chromosome counts are reported for 76 taxa and 2 natural hybrids of tribe Senecioneae (Compositae). First counts are reported for several species of Senecioneae as well as for the genera Cadiscus and Whitneya. New chromosome numbers are added to those previously known in Arnica, Cacalia, and Senecio. Additional counts from Arnica support our previous suggestion that x = 19 for this genus. It is assumed that observed meiotic irregularities are associated with apomixis in this genus. Basic chromosome numbers for various New World sections of Senecio are proposed, and certain problems of sectional relationships in this genus are discussed. Chromosome numbers and plant morphology of Cadiscus, Hulsea, and Whitneya indicate that these genera should be removed from Helenieae to Senecioneae. The possible affinity of the anomalous genus Adenocaulon with Mutisieae is discussed. Data presented in the paper further support our earlier proposal that the basic chromosome number for Senecioneae is x = 10.  相似文献   

2.
A theory of diffusion control within hollow fiber catalysts is derived for three different types of coordinate geometries: Cartesian, cylindrical, and spherical. Effectiveness factors are calculated and formulas for reactant conversion in both a fixed-bed and a contimunuous-feed stirred-tank reactor are derived. The apparent Michaelis constant, Km′, is a measure of the amount of diffusion control within the catalysts. When Km′ is equal to Km, the true Michaelis constant, there is no diffusion control. In all other cases Km′ is greater than Km. Hollow fibers are attractive alternatives to spherical microcapsules for the encapsulation of enzymes.  相似文献   

3.
Abstract

Several quantitative and qualitative seed characters of the seven European species of Erica sect. Loxomeria, Eremocallis and Brachycallis were studied. Two main seed types are found based on size and shape: regular ellipsoid or oblong seeds of ca. 0.4 mm for E. ciliaris and the E. tetralix group, and curved to kidney‐shaped seeds of 0.6–0.9 mm for E. cinerea, E. maderensis and E. terminalis. The testa surface in E. ciliaris is reticulate, with indented outer periclinal walls. Erica cinerea has inflated outer anticlinal walls. This character is exclusive for this species within the European (and nearby areas) species of the genus. The seeds of E. maderensis are similar to those of E. terminalis. According to seed morphology, the classical infrageneric classification, by which E. terminalis would be grouped with the E. tetralix group in sect. Eremocallis and E. maderensis in sect. Brachycallis with E. cinerea, is artificial.  相似文献   

4.
5.
Immunoelectrophoretic studies of the seed proteins of material provisionally referred to B. secalinus var. or f. hirsutus have revealed that it is serologically distinct from B. secalinus. The plant has many of the characters of B. secalinus fitting that species to life as a contaminant of cereal fields, but the floret and seed sizes are much smaller, and the sheaths are normally hairy. In Britain the plant appears to contaminate small-seeded pasture grasses which are sown on roadsides. The chromosome number of this plant is 2n = 14, unlike typical B. secalinus which has 2n = 28. The plant seems to be introduced in Britain, but its native distribution is not known. In view of its distinctive morphology and its serological difference from B. secalinus and other bromes, it is proposed to name it as a new species: Bromus pseudosecalinus P. SMITH sp. nov.  相似文献   

6.
7.
ABSTRACT. Based on both morphological and molecular information, two new euplotid genera Apodiophrys n. g. and Heterodiophrys n. g. are described in the present paper. Apodiophrys n. g. is defined as sculptured Diophryinae with bipartite adoral zone; frontoventral cirri arranged in Diophrys‐pattern; marginal cirri located in two clearly separated groups. Heterodiophrys n. g. is recognizable by the combination of Diophrys‐like frontoventral cirri and the unique structure of several marginal cirri that are arranged in a long row. The type species for both new genera, Apodiophrys ovalis n. sp. and Heterodiophrys zhui n. sp., collected from southern China sea, are described. The small subunit rRNA (SSU rRNA) gene sequences for both new taxa are determined. Phylogenetic analyses based on these data indicate that Apodiophrys is most closely related to Paradiophrys, which then clusters with Uronychia species. Thus, Apodiophrys–Paradiophrys is separated from other typical Diophrys‐like genera in the SSU rRNA gene trees. The new genus Heterodiophrys is basal to the sister group of Diophrys–Diophryopsis, hence belongs to the “core”Diophrys‐complex.  相似文献   

8.
A. Vilenkin 《Biopolymers》1977,16(8):1657-1675
A new technique is presented for treating the ground state of an heteropolymer with a random sequence of components. An exact system of equations is found for determining the ground state energy E which is equal to the polymer free energy f in the lowest-order approximation in T/V (V/2 is the large “surface” energy arising at the boundaries between coiled and “helical” sections: V ? T, Uk; U1 and –U2 are the free energies of the components counted from the corresponding coiled state energies). These equations are essentially simplified at certain fixed values of the ratio U1/U2. For integer values of U2/U1 and U1/U2 a solution is obtained with an accuracy exp(–V/Uk). The ground-state energy as a function of U1 and U2 is shown to be highly irregular: its derivatives have jumps at an infinite number of points. These jumps provide a fine structure of the melting curves. A smoothed over the jumps function E′ is found by way of analytic continuation from the integer values of U1/U2 and U2/U1. The accuracy of the approximation fE is estimated and the correctional term of order T/V is determined.  相似文献   

9.
SYNOPSIS. Eimeria vermiformis sp. n. and E. papillata sp. n. are described from the mouse Mus musculus. The sporulated oocysts of E. vermiformis are 18–26 by 15–21 μ (mean 23.1 by 18.4 μ); its sporocysts are 11–14 by 6–10 μ (mean 12.8 by 7.9 p). The sporulated oocysts of E. papillata are 18–26 by 16–24 μ (mean 22.4 by 19.2 μ); its sporocysts are 10–13 by 6–9 μ (mean 11.2 by 8.0 μ). A substiedal body is present in E. papillata sporocysts. Patent infections were produced in white laboratory mice with both species. Fourteen species of Eimeria have now been described from the genus Mus.  相似文献   

10.
Two new methanogenic bacteria, Methanocorpusculum sinense spec. nov. strain DSM 4274 from a pilot plant for treatment of distillery wastewater in Chengdu (Province Sichuan, China), and Methanocorpusculum bavaricum spec. nov. strain DSM 4179, from a wastewater pond of the sugar factory in Regensburg (Bavaria, FRG) are described. Methanocorpusculum strains are weakly motile and form irregularly coccoid cells, about 1 μm in diameter. The cell envelope consists of a cytoplasmic membrane and a S-layer, composed of hexagonally arranged glycoprotein subunits with molecular weights of 90000 (Methanocorpusculum parvum), 92000 (M. sinense), and 94000 (M. bavaricum). The center-to-center spacings are 14.3 nm, 15.8 nm and 16.0 nm, respectively. Optimal growth of strains is obtained in the mesophilic temperature range and at a pH around 7. Methane is produced from H2/CO2, formate, 2-propanol/CO2 and 2-butanol/CO2 by M. parvum and M. bavaricum, whereas M. sinense can only utilize H2/CO2 and formate. Growth of M. sinense and M. bavaricum is dependent on the presence of clarified rumen fluid. The G+C content of the DNA of the three strains is ranging from 47.7–53.6 mol% as determined by different methods. A similar, but distinct polar lipid pattern indicates a close relationship between the three Methanocorpusculum species. The polyamine patterns of M. parvum, M. sinense and M. bavaricum are similar, but distinct from those of other methanogens and are characterized by a high concentration of the otherwise rare 1,3-diaminopropane. Quantitative comparison of the antigenic fingerprint of members of Methanocorpusculum revealed no antigenic relationship with any one of the reference methanogens tested. On the basis of the distant phylogenetic position of M. parvum and the data presented in this paper a new family, the Methanocorpusculaceae fam. nov., is defined.  相似文献   

11.
Cousinia kermanensis sp. nov. (sect. Congestae Bunge) and C. pulcherantha sp. nov. (sect. Leiocaules Bunge) are described from Kerman in southeastern Iran. These species are compared to their closest related species, C. decurrens Regel and C. oophora Rech. f., respectively. The habitat of C. kermanensis is lowland mountains or hills with poor soils inside the steppe of Artemisia sieberi Besser. Cousinia pulcherantha grows on highland slopes of mountains with deep soils inside the steppe of Artemisia aucheri Boiss. Illustrations of the new species are presented.  相似文献   

12.
《Journal of bryology》2013,35(4):363-373
Abstract

Three new species of Cololejeunea, C. dianae M. Wigginton, C. sanctae-helenae M. Wigginton and C. grossestyla M. Wigginton are described and illustrated from St Helena, South Atlantic Ocean. Details of their distributions are provided, and differences between the new taxa and other species of Cololejeunea are discussed. This is also the first report of the genus Cololejeunea from St Helena.  相似文献   

13.
The history, ecology, and distribution of Camassia leichtlinii are given and particularly the deep violet cultivar of subsp. suksdorfii‘Lady Eva Price’, which is illustrated. The position of Camassia within the Liliaceae sens. lat. is discussed in the light of recent DNA studies.  相似文献   

14.
《Journal of bryology》2013,35(4):635-647
Abstract

The results of a comparative study of Pohlia muyldermansii from Continental Europe and the British Isles are presented. Two varieties are recognized, var. muyldermansii from Belgium and the Netherlands and var. pseudomuyldermansii var. nov. from Great Britain, Ireland, Austria and Switzerland. P. camptotrachela is reported from Belgium and differences between this species and P. muyldermansii discussed.  相似文献   

15.
The geographic distribution of three closely related Hyalomma species, namely Hyalomma (Euhyalomma) truncatum Koch, 1844, Hyalomma (Euhyalomma) albiparmatum Schulze, 1919 and Hyalomma (Euhyalomma) nitidum Schulze, 1919 is confined to Africa. A detailed comparison of all stages of development of the three taxa reveals that they possess many more shared than distinguishing characters. In fact differentiation between these species is based on single or dual qualitative characters on their adults. These are a conspicuous, ivory-coloured parma on H. (E.) albiparmatum males, and the absence or reduction in clarity of ivory-coloured bands on the leg segments of H. (E.) nitidum adults, as well as the shape of the external cuticular preatrial fold of the genital operculum of females of the latter species. The adults of all three species and the larva of H. (E.) truncatum are redescribed. The nymph of H. truncatum and the larva and nymph of H. (E.) albiparmatum and H. (E.) nitidum are described for the first time. Data on their geographic distributions and hosts are provided.  相似文献   

16.
A new genus from a Middle Devonian locality near Cairo, N. Y., is described. Actinoxylon gen. nov. is based upon pyritic petrifactions. Three orders of branching are present: penultimate branch, ultimate branch, and leaf. The penultimate branch bears spirally arranged ultimate branches and leaves, the leaves apparently replacing the branches in the spiral. The ultimate branches bear opposite to subopposite and decussate leaves. The leaves are non-planated, unwebbed structures which show at least three dichotomies. Each segment of the leaf is terete as are all other axes. Internally the penultimate branch has a six-lobed actinostele with mesarch protoxylem areas, one or two per lobe. Secondary xylem is visible in the oldest parts of several specimens. The xylem has helical-reticulate, reticulate, scalariform and circular-pitted elements. The presumptive areas of phloem are occupied by cells with dark contents. The cortex is composed of a parenchymatous inner region and a sclerenchymatous outer region. The ultimate branch traces are at first three-lobed protosteles, later becoming four-lobed. Several ultimate branch traces also possess secondary xylem while within the cortex of the penultimate branch. The leaf traces are terete strands. Below each forking of a leaf segment there is a corresponding forking of the vascular strand. Actinoxylon is compared with the progymnosperms Actinopodium, Svalbardia, Archaeopteris, Siderella, and Tetraxylopteris. The anatomy of the penultimate branch of Actinoxylon is similar to that of Actinopodium, Archaeopteris macilenta, and Siderella. The ultimate branch traces of Archaeopteris and Actinoxylon are similar. The ultimate branch stele and pattern of trace formation in Actinoxylon is similar to the stelar configuration and trace formation in the r + 2 axes of Tetraxylopteris schmidtii. The unwebbed leaves are similar to those of Archaeopteris fissilis, Svalbardia, and the terminal units of the Aneurophytales.  相似文献   

17.
The organ bearing the sporangia of Biscalitheca kansana is a laminate rachis with subopposite fertile appendages, a structure previously unknown for Biscalitheca. The sporangia differ from those of the petrified Biscalitheca musata only by lacking nests of sclerotic cells. They contain spores which are called Convolutispora when found dispersed. Speculations are made that Monoscalitheca fasciculata will ultimately be regarded as a synonym of Biscalitheca musala and that some fossils called Aphlebia and Brittsia problematica may be the sterile foliage of zygopterids.  相似文献   

18.
The habitat and discovery of Salvia raymondii is described and the distinctions between the type subspecies and subsp. mairanae are discussed. Subsp. mairanae is illustrated and notes on its cultivation are provided.  相似文献   

19.
The genus Miliusa in Cambodia and Vietnam is reviewed. Cambodia and Vietnam each harbors six species of Miliusa, including three which are described as new to science: one from Cambodia (Miliusa cambodgensis sp. nov.), the other two from Vietnam (M. astiana and M. ninhbinhensis spp. nov.). In addition, a complete nomenclature and relevant information about the Miliusa species previously known from Cambodia and Vietnam are provided, including keys to the Cambodian and Vietnamese species, the designation of a lectotype for M. baillonii and the synonymization of M. balansae var. elongatoides, M. chunii and M. sinensis with M. balansae.  相似文献   

20.
Summary Two new nitrite oxidizing bacteria for which the names Nitrococcus mobilis and Nitrospina gracilis are proposed were isolated from the marine environment. Nitrococcus mobilis was cultured from South Pacific waters and it is a large motile coccus with unique tubular cytomembranes. Nitrospina gracilis was isolated from South Atlantic waters and it is a long slender rod which lacks an extensive cytomembrane system. Both are obligate marine organisms and both are obligate chemoautotrophs. The fine structure of these organisms is detailed.Contribution No. 2631 from the Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543.  相似文献   

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