Seed morphology of Erica L. sect. Loxomeria Salisb. ex Benth., sect. Eremocallis Salisb. ex Benth. and sect. Brachycallis I. Hansen,and its systematic implications

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.     

Helix-coiled transition in heteropolymers. I. Ground-state energy

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, U_k; 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/U_k). 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 f ≈ E is estimated and the correctional term of order T/V is determined.     

Opalinidae in African Anura. II. Genera Protozelleriella n. g. and Zelleriella

During 1988 and 1989, 409 specimens of southern African Anura, comprising 50 species in 9 families, were checked for opalinids in the cloaca. Protozelleriella devilliersi n. g., n. sp. was found in three of four Capensibufo rosei (Bufonidae); Zelleriella africana Sandon, 1938 in two of three Bufo angusticeps and one of 20 B. garmani (Bufonidae) plus three of 12 Phrynobatrachus natalensis, 12 of 19 Tomopterna cryptotis, seven of 14 T. delalandii, three of seven T. krugerensis and one of six T. natalensis (all Ranidae); Z. gambieri n. sp. in one of six T. natalensis; Z. garlandi n. sp. in two of six Kassina maculata (Hyperoliidae); Z. sandoni n. sp. in two of 20 B. garmani, two of six K. maculata, one of seven K. senegalensis and one of four Leptopelis mossambicus (Hyperoliidae) plus one of five Phrynomerus bifasciatus (Microhylidae) and two of 19 T. cryptotis. It is suggested that the Ranidae (in particular the genus Tomopterna) and the Hyperoliidae are among the major carriers of Zelleriella in the Afrotropical Region.     

Haplodontium zangii X.R.Wang & J.C.Zhao,sp. nov. (Bryaceae,Bryopsida) from Xizang,China

Haplodontium zangii X.R.Wang &; J.C.Zhao, a new moss species from Xizang, China, is described and illustrated. Previously, specimens of H. zangii have been identified as Mielichhoferia himalayana Mitt. However, H. zangii is distinctly different from M. himalayana in having excurrent costae with short awns (vs long denticulate awns), short-pyriform capsules, 0.8–1?mm (vs long-pyriform capsules, 2.5–3?mm), and densely papillose exostome teeth (vs smooth or vertically striped exostome teeth). Haplodontium zangii is similar to H. macrocarpum (Hook.) J.R.Spence, which was traditionally placed in Mielichhoferia Nees &; Hornsch. as M. macrocarpa (Hook.) Bruch &; Schimp. The main differences between H. zangii and H. macrocarpum are in the morphology of the leaves, capsules, guide cells, and stomata. Mielichhoferia himalayana and another Chinese species of Mielichhoferia, M. sinensis Dix., are also transferred to Haplodontium Hampe, a new genus in the bryoflora of China, as H. himalayanum (Mitt.) X.R.Wang &; J.C.Zhao and H. sinensis (Dix.) X.R.Wang &; J.C.Zhao. A morphological comparison and a key to the three species of Haplodontium in China as well as to H. macrocarpum, a species that is likely to be found in China, are provided.     

CHROMOSOME NUMBERS IN COMPOSITAE. VI. SENECIONEAE. II

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.     

Plagiochila atlantica F. Rose,sp. nov.—P. amhagiosa auct.

Abstract

The Irish plant which, following Mitten, has commonly been referred to as Plagiochila ambagiosa Mitt. is specifically different from the type of P. ambagiosa, and is therefore described as Plagiochila atlantica F. Rose, sp. nov. It is now known from very restricted areas in Western Ireland, Western Scotland and North-western France.     

Recombinant plasmids capable to replication in B. subtilis and E. coli.

Summary The plasmid pBC16 (4.25 kbases), originally isolated from Bacillus cereus, determines tetracycline resistance and can be transformed into competent cells of B. subtilis. A miniplasmid of pBC16 (pBC16-1), 2,7 kb) which has lost an EcoRI fragment of pBC16 retains the replication functions and the tetracycline resistance. This plasmid which carries only one EcoRI site has been joined in vitro to pBS1, a cryptic plasmid previously isolated from B. subtilis and shown to carry also a single EcoRI site (Bernhard et al., 1978). The recombinant plasmid is unstable and dissociates into the plasmid pBS161 (8.2 kb) and the smaller plasmid pBS162 (2.1 kb). Plasmid pBS161 retains the tetracycline resistance. It possesses a single EcoRI site and 6 HindIII sites. The largest HindIII fragment of pBS161 carries the tetracycline resistance gene and the replication function. After circularization in vitro of this fragment a new plasmid, pBS161-1 is generated, which can be used as a HindIII and EcoRI cloning vector in Bacillus subtilis.Hybrid plasmids consisting of the E. coli plasmids pBR322, pWL7 or pAC184 and different HindIII fragments of pBS161 were constructed in vitro. Hybrids containing together with the E. coli plasmid the largest HindIII fragment of pBS161 can replicate in E. coli and B. subtilis. In E. coli only the replicon of the E. coli plasmid part is functioning whereas in B. subtilis replication of the hybrid plasmid is under the control of the Bacillus replicon. The tetracycline resistance of the B. subtilis plasmid is expressed in E. coli, but several antibiotic resistances of the E. coli plasmids (ampicillin, kanamycin and chloramphenicol) are not expressed in B. subtilis. The hybrid plasmids seem to be more unstable in B. subtilis than in E. coli.     

Multiphase catalysis. II. Hollow fiber catalysts

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, K_m′, is a measure of the amount of diffusion control within the catalysts. When K_m′ is equal to K_m, the true Michaelis constant, there is no diffusion control. In all other cases K_m′ is greater than K_m. Hollow fibers are attractive alternatives to spherical microcapsules for the encapsulation of enzymes.     

Revision of Corallinaceae (Corallinales,Rhodophyta): recognizing Dawsoniolithon gen. nov., Parvicellularium gen. nov. and Chamberlainoideae subfam. nov. containing Chamberlainium gen. nov. and Pneophyllum

A multi‐gene (SSU, LSU, psbA, and COI) molecular phylogeny of the family Corallinaceae (excluding the subfamilies Lithophylloideae and Corallinoideae) showed a paraphyletic grouping of six monophyletic clades. Pneophyllum and Spongites were reassessed and recircumscribed using DNA sequence data integrated with morpho‐anatomical comparisons of type material and recently collected specimens. We propose Chamberlainoideae subfam. nov., including the type genus Chamberlainium gen. nov., with C. tumidum comb. nov. as the generitype, and Pneophyllum. Chamberlainium is established to include several taxa previously ascribed to Spongites, the generitype of which currently resides in Neogoniolithoideae. Additionally we propose two new genera, Dawsoniolithon gen. nov. (Metagoniolithoideae), with D. conicum comb. nov. as the generitype and Parvicellularium gen. nov. (subfamily incertae sedis), with P. leonardi sp. nov. as the generitype. Chamberlainoideae has no diagnostic morpho‐anatomical features that enable one to assign specimens to it without DNA sequence data, and it is the first subfamily to possess both Type 1 (Chamberlainium) and Type 2 (Pneophyllum) tetra/bisporangial conceptacle roof development. Two characters distinguish Chamberlainium from Spongites: tetra/biasporangial conceptacle chamber diameter (<300 μm in Chamberlainium vs. >300 μm in Spongites) and tetra/bisporangial conceptacle roof thickness (<8 cells in Chamberlainium vs. >8 cells in Spongites). Two characters also distinguish Pneophyllum from Dawsoniolithon: tetra/bisporangial conceptacle roof thickness (<8 cells in Pneophyllum vs. >8 cells in Dawsoniolithon) and thallus construction (dimerous in Pneophyllum vs. monomerous in Dawsoniolithon).     

Zur Cytotaxonomie vonArabis hirsuta agg. (Cruciferae). IV. Chromosomenzahlen vonA. sagittata (Bertol.) DC. undA. hirsuta (L.)Scop. s. str. aus Europa

Zusammenfassung A. sagittata (Bertol.) DC. von zehn Herkünften aus Europa ist mit 2 n=16 diploid.A. hirsuta (L.)Scop. s. str. einschließlich der sicherlich hierhergehörigen var.glaberrima Wahlenb. von 30 europäischen Herkünften ist mit 2 n=32 tetraploid; diploide Pflanzen konnten beiA. hirsuta s. str. nicht gefunden werden.

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Summary A. sagittata (Bertol.) DC. from 10 different places in Europe has 2 n=16 chromosomes and is diploid.A. hirsuta (L.)Scop. s. str., its var.glaberrima Wahlenb. being included, has been investigated from 30 provenances in Europe, it has the tetraploid chromosome number 2 n=32, diploid plants could not be found in this species.A. hirsuta var.glaberrima (2 n=32) is surely belonging toA. hirsuta s. str. and not toA. allionii (2 n=16).

     

Electrostatic effects on polynucleotide transitions. II. Behavior of titrated systems

The theory developed in the previous paper to discuss changes in electrostatic free energies in polynucleotide order–disorder transitions is extended to cases where one or more of the participating species is titrated to some degree α. It is shown that, for any class of transition, the melting temperature T_m at constant pH is a linear function of the logarithm of the monovalent counterion concentration M, that at high salt the logarithm of the depression of the melting temperature by pH titration is proportional to the pH change, and that the stability of the ordered form as measured by its melting temperature at neutral pH, is a monotonic function of the quantity pH_m – pK, where pH_m and pK are the pH of melting and the monomer base pK, both measured under similar conditions of temperature and ionic strength. For the transition from double helix to coil, the dependences of T_m and dT_m/d log M on pH are determined experimentally and compared with the qualitative predictions of the theory. It is found that dT_m/dlog M, a measure of – ΔF?^el (the negative of the electrostatic free energy change in the transition), decreases with increasing pH. In acid solution, where the coil is more extensively prolonated than the helix, the change in electrostatic free energy in the transition is larger than at neutral pH. Conversely, in alkali the electrostatic five energy change is smaller than at neutral pH. Hence (dT_m/d log M)_acid > (dT_m/d log M _neutral) > (dT_m/d log M)_alkali. At Suffeciently high pH, dT_m/d log M is observed to become negative, indicating that the electrostatic free energy change is positive in the transition of this region. Date from the literature on the ionic strength dependence of the melting temperature for the acid helices of poly rA, poly rC, and poly dC are also considered from the standpoint of the theory.     

CHROMOSOME NUMBERS IN COMPOSITAE. IV. AMBROSIEAE

New chromosome observations are reported for 30 species and varieties from 4 genera of Ambrosieae: Ambrosia (including Franseria), Diceria, Hymenoclea and Iva. Neither polyploidy nor aneuploidy is known in the genera Dicorea, Hymenoclea or Xanthium. Aneuplcid reduction appears to have played a role in the genome evolution of several species of Iva and Ambrosia. Polyploid species occur in both Iva and Ambrosia and polyploid series exist for at least 5 species or species aggregates of the latter. All available evidence indicates that the primitive chromosome number for the tribe is x = 18, differentiation and speciation having occurred at this level, which is here termed diploid. The group, however, must ultimately have been of polyploid origin from forms with x = 9.     

Studies in Heterobasidiomycetes,Part 38*)Sphacelotheca polygoni-persicariae G. Demi & Oberw. spec. nov.

A new species, Sphacelotheca polygoni-persicariae, parasitizing the ovaries of Polygonum persicaria L. is described. This smut, collected several times in Madeira, Portugal, differs from other species of that genus, by its host plant and the reticulated teliospore ornamentation. On the basis of the morphological and ultrastructural characters of S. polygoni-persicariae, in connection with some recently published data on siderophore formation and 5S ribosomal RNA sequences it can be assumed that 1) members of the genus Sphacelotheca are separated from typical Ustilago species of Poaceae, 2) Sphacelotheca is restricted to species parasitizing Polygonaceae, and 3) species of Sphacelotheca and Microhotryum as well as those Ustilago species which parasitize in the flowers of Polygonaceae are closely related.     

The erection of Pelecanema n. g. (Nematoda: Spirurida: Acuariidae), with redescriptions of P. sirry (Khalil, 1931) n. comb. and P. pelecani (Johnston & Mawson, 1942) n. comb.

Pelecanema n. g. is erected for P. sirry (Khalil, 1931) n. comb., syn. Synhimantus sirry Khalil, 1931 (type-species) and P. pelecani (Johnston & Mawson, 1942) n. comb., syn. Dispharynx pelecani Johnston & Mawson, 1942. In the structure of its cordons, consisting of two rows of delicate cuticular plates, the new genus is similar to Synhimantus Railliet, Henry & Sisoff, 1912, Dispharynx Railliet, Henry & Sisoff, 1912, Chordatortilis Machado de Mendon?a & Olivera de Rodrigues, 1965 and Parachordatortilis Mutafchiev, Santoro & Georgiev, 2010. Pelecanema sirry, a parasite of Pelecanus onocrotalus L. and P. crispus Bruch (Pelecaniformes, Pelecanidae) in Africa (Egypt and Senegal) and Europe (Ukraine and Bulgaria), is redescribed using light and scanning electron microscopy on the basis of specimens from P. crispus from Bulgaria. Pelecanema pelecani, a parasite of Pelecanus conspicillatus Temminck in Australia, is also redescribed using light microscopy on the basis of specimens from its type-host and type-locality. In contrast to a previous opinion recognising Pelecanema sirry and P. pelecani as synonyms, the two species are considered distinct and P. pelecani is validated.     

PHYCOLOGICAL NOTES. H. EUGLENA MYXOCYLINDRACEA SP. NOV.12

A previously undescribed species of Euglena, E. myxocylindracea, sp. nov., is described from soil in a garden and in a while pine woods in Pike County, Pa. In addition to the, type, an organism (No. 457) in the Culture Collection of Algae. Indiana University, hitherto designated E. viridis var. terricola. is transferred to E. myxocylindracea as var. terricola. Differences such as the usual absence of an emergent flagellum, or the presence of an extremely short one (ca. 3.5–4 μ), and the dominance of a palmelloid state in a variety of liquid and solid culture media in which the cells secrete dichotomously branching slimy cylinders distinguish the new species from E. viridis.     

On the identity of Pohlia flexuosa Harv. with P. muyldermansii Wilcz. & Dem.

Abstract

The identity of Pohlia flexuosa Harv. with P. muyldermansii Wilcz. & Dem. is established. Recent gatherings from several Asiatic countries demonstrate that material of P. flexuosa occurs with propagula identical with those of P. muyldermansii var. muyldermansii, of var. pseudomuyldermansii Arts, Nordhorn-Richter and Smith and with a mixture of both and intermediate types of propagulum; var. pseudomuyldermansii cannot therefore be upheld as distinct. It is postulated that P. flexuosa has been introduced into Europe in two distinctive clones.     

Isothecium myosuroides var. brachythecioides (Dixon) Braithw. reinstated as a species,I. interludens Stirt.

The taxon currently known as Isothecium myosuroides var. brachythecioides (Dixon) Braithw. is reinstated as a species, I. interludens Stirt., the name originally assigned by Stirton when it was first described. The morphological characters separating I. myosuroides s.s. and I. interludens are summarised. The sporophytes of I. interludens, described here for the first time, differ in shape, and pattern of exothecial cells from those of I. myosuroides. A molecular analysis based on variation of the ITS region shows that I. holtii Kindb. and I. alopecuroides (Lam. ex Dubois) Isov. are not monophyletic, calling for a re-assessment of these species, whereas the monophyly of the other species, including I. interludens, cannot be rejected. The analysis failed, however, to yield molecular synapomorphies for I. interludens and other species within I. myosuroides s.l., which we interpret as the incomplete sorting of alleles among recently evolved species. Isothecium interludens is a European endemic with a hyperoceanic temperate distribution. Its nested position within a clade including the two Macaronesian endemics I. prolixum (Mitt.) M.Stech and I. montanum Draper, Hedenäs, M.Stech, T.Lopes & Sim-Sim is suggestive of a Macaronesian origin, in line with the idea that the European Atlantic fringe flora assembled during the course of the last interglacial from Macaronesian ancestors. Isothecium therefore offers a model of prime importance for the study of ongoing speciation in mosses.     

Contributions to the Flora of Spitsbergen,especially of Red bay,from the Collections of W. S. Bruce,F.R.S.G.S., Naturalist to the Prince of Monaco's Expeditions of 1898 and 1899

Background: Prescribed burning in peatlands is controversial due to concerns over damage to their ecological functioning, particularly regarding their key genus Sphagnum. However, empirical evidence is scarce.

Aims: The aim of the article is to quantify Sphagnum recovery following prescribed burns.

Methods: We completed nine fires at a raised bog in Scotland, achieving a range of fire severities by simulating drought in some plots. We measured Sphagnum cover and chlorophyll fluorescence F_v/F_m ratio (an estimate of photosynthetic capacity) up to 36 months post-fire.

Results: Cover of dominant Sphagnum capillifolium was similar in unburnt and burnt plots, likely due to its high moisture content which prevented combustion. Burning decreased S. capillifolium F_v/F_m 5 months after fire from 0.67 in unburnt plots to 0.44 in low fire severity plots and 0.24 in higher fire severity (drought) plots. After 22 months, F_v/F_m in burnt plots showed a healthy photosynthetic capacity of 0.76 and no differences between severity treatments. Other Sphagnum species showed similar post-fire recovery though their low overall abundance precluded formal statistical analysis.

Conclusions: S. capillifolium is resilient to low–moderate fire severities and the same may be true for a number of other species. This suggests that carefully applied managed burning can be compatible with the conservation of peatland ecosystem function.     

Nervostroma, gen. nov. in the Sclerotiniaceae, the teleomorph of Cristulariella, and Hinomyces anam. gen. nov. to accommodate the anamorph of Grovesinia: reassessment of the genus Cristulariella

Taxonomy of the genus Cristulariella is revised, retaining Cristulariella (Crist.) depraedans as the type. Two new species, Crist. cercidiphylli and Crist. corni, are additionally described under the genus. The new anamorphic genus Hinomyces is erected to accommodate Botrytis (Cristulariella) moricola and Cristulariella pruni. A new genus and species, Nervostroma depraedans, is erected in the Sclerotiniaceae to accommodate the teleomorph of Crist. depraedans, with an additional species, Nervostroma cercidiphylli.