Hybridization between Arctostaphylos viscida and A. canescens in Oregon

Evidence of natural hybridization betweenArctostaphylos viscida andA. canescens in southwestern Oregon was obtained from morphological studies of field populations. Hybridization occurs where populations ofA. viscida andA. canescens meet in areas where serpentine and nonserpentine soils abut. At these contacts,A. viscida forms large populations only on serpentine andA. canescens only on nonserpentine. Most of the indentifiable hybrids survive on either transitional or nonserpentine soils. The small proportion that are found on serpentine are considered to be backcrosses toA. viscida. The hybrid plants are similar to several putative species maintained in the standard floras, and it is suggested that these no longer be given taxonomic recognition.     

Correlations between the ages of<Emphasis Type="Italic">Alnus</Emphasis> host species and the genetic diversity of associated endosymbiotic<Emphasis Type="Italic">Frankia</Emphasis> strains from nodules

Nodule samples were collected from four alder species:Alnus nepalensis, A. sibirica, A. tinctoria andA. mandshurica growing in different environments on Gaoligong Mountains, Yunnan Province of Southwest China and on Changbai Mountains, Jilin Province of Northeast China. PCR-RFLP analysis of the IGS betweennifD andnifK genes was directly applied to unculturedFrankia strains in the nodules. A total of 21 restriction patterns were obtained. TheFrankia population in the nodules ofA. nepalensis had the highest genetic diversity among all fourFrankia populations; by contrast, the population in the nodules ofA. mandshurica had the lowest degree of divergence; the ones in the nodules ofA. sibirica andA. tinctoria were intermediate. A dendrogram, which was constructed based on the genetic distance between the restriction patterns, indicated thatFrankia strains fromA. sibirica andA. tinctoria had a close genetic relationship.Frankia strains fromA. nepalensis might be the ancestor ofFrankia strains infecting otherAlnus species. From these results and the inference of the ages ofAlnus host species, it is deduced that there was a co-evolution betweenAlnus and its microsymbiontFrankia in China.     

Notes on Bletia (Orchidaceae)

New species ofBletia from Mexico are described and illustrated:B. concolor, B. similis, andB. urbana. The identity ofB. campanulata Llave & Lex. is discussed, andB. reflexa Lindl. is considered to be a distinct species. Several South American epithets are treated as synonyms ofB. campanulata. A key to the recognized species ofBletia is given.     

Evidence for the hybrid origin of Flaveria latifolia (Compositae)

Investigations of natural populations, cytological studies, and comparisons of herbarium specimens have been used to clarify the taxonomy of the Florida species ofFlaveria. These studies indicate thatF. latifolia is a hybrid betweenF. linearis andF. floridana. Apparently the “latifolia” plants represent stabilized populations that have become adapted to the fill material dredged from the ocean and used in road building and land development in southern Florida. The wide variation noted in populations ofF. linearis andF. floridana is attributed to introgression. The paper includes a taxonomic treatment of the six species which occur in Florida. AU taxa are diploid with 2n = 36.     

Molecular biological taxonomy of some free-living nitrogen-fixing bacteria

A novel approach to the taxonomy of several free-living nitrogen-fixing bacteria is proposed on the basis of two DNA parameters. 1) DNA base composition, expressed as average molar (guanine + cytosine) content, determined by thermal denaturation and 2) DNA homology, determined by DNA hybridization with bothPseudomonas fluorescens andPseudomonas putida. The following taxonomic conclusions emerged:

1. 1.
   The existence ofBeijerinckia andDerxia as individual genera seems justified.     
   
   

Chromosome number variability in central european members of the<Emphasis Type="Italic">Festuca ovina</Emphasis> and<Emphasis Type="Italic">F. pallens</Emphasis> groups (sect.<Emphasis Type="Italic">Festuca</Emphasis>)

Chromosome numbers for 98 plants ofF. pallens, 19 ofF. psammophila, F. belensis andF. vaginata, and 44 ofF. ovina (originating from Austria, the Czech Republic, Germany, Slovakia and Latvia) are given. In addition to theF. ovina andF. pallens groups, chromosome counts for the following taxa are also reported:F. alpestris (2n=14) reported for the first time in this work,F. amethystina subsp.amethystina (2n=28),F. brevipila (2n=42),F. cinerea (2n=28),F. rupicola subsp.rupicola (2n=42) andF. versicolor subsp.versicolor (2n=14).InF. pallens, two ploidy levels (2n=2x=14+0-1B, 2n=4x=28+0-1B) as well as two natural triploid plants (2n=21+0-1B), were found. In addition to the fourF. pallens types that have been distinguished in Austria, one new tetraploid type (F. pallens “scabrifolia”) from the Czech Republic and Germany is reported and its taxonomy is discussed. The distributions of the Oberösterreich-Niederösterreich and Pannonisches-HügellandF. pallens types outside of Austria are documented.Only the diploid chromosome number (2n=14) was found inF. psammophila andF. vaginata. Chromosome numbers forF. psammophila subsp.muellerstollii andF. belensis (both 2n=14) were determined here for the first time. Two ploidy levels, 2n=14+0-5B corresponding toF. ovina subsp.ovina and 2n=28 corresponding toF. ovina subsp.guestphalica andF. cf.duernsteinensis were confirmed inF. ovina. Differences in chromosome structure (simple and multiple secondary constrictions) betweenF. pallens as opposed toF. psammophila andF. vaginata are discussed. A complete survey of published chromosome counts for Central European species from theF. ovina andF. pallens groups is included.     

Karyo-taxonomic study of the genus<Emphasis Type="Italic">Pseudolysimachion</Emphasis> (<Emphasis Type="Italic">Scrophulariaceae</Emphasis>) in the Czech Republic and Slovakia

Flow cytometry was used to determine ploidy levels in the Czech and Slovak taxa of the genusPseudolysimachion (W.D.J. Koch)Opiz (=Veronica auct. p.p.,Scrophulariaceae). In total, 123 populations from the Czech Republic, Slovakia, Ukraine (one locality), Austria (one locality) and Hungary (one locality) were analyzed. InP. maritimum (L.)Á. Löve etD. Löve andP. spicatum (L.)Opiz, two cytotypes were found: diploid (2n=2x=34) and tetraploid (2n=4x=68). In both species the tetraploid cytotype predominated (P. maritimum: 41 tetraploid populations out of 45;P. spicatum: 57 tetraploid populations out of 58). The two cytotypes ofP. maritimum have no taxonomic significance because ploidy level is not obviously correlated with morphology, distribution pattern or ecology. Tetraploid populations ofP. spicatum belong to two morphologically different subspecies, subsp.spicatum and subsp.fischeri Trávní?ek. The diploid cytotype (one population only) should be provisionally classified as a third subspecies ofP. spicatum, which is morphologically similar to the Asian subsp.porphyrianum (Pavlov)Trávní?ek. Only diploid plants (2n=2x=34) ofP. orchideum (Crantz)Wraber were found; all 13 populations that were analyzed belong toP. orchideum s.str. One diploid population sample ofP. spurium subsp.foliosum (Waldst. etKit.)Holub (2n=2x=34) and one tetraploid sample ofP. incanum subsp.pallens (Host)Trávní?ek (2n=4x=68) were also analyzed. In addition, three tetraploid populations of hybrid origin were investigated:P. maritimum ×P. spicatum subsp.spicatum (one population) andP. maritimum ×P. spurium subsp.foliosum (two populations). While hybrid plants ofP. maritimum ×P. spicatum arose from tetraploid parental species, plants ofP. maritimum ×P. spurium probably resulted from a cross between tetraploidP. maritimum and diploidP. spurium. The putative origin and evolutionary importance of polyploids in thePseudolysimachion are discussed.     

Antibiotic activity of fungi isolated from soil samples from Indonesia

Two hundred and thirteen fungal cultures were recovered from 88 soil samples from different parts of Indonesia; 39.4% belonged to the genusPenicillium, 19.7% to the genusAspergillus, 9.9% to the genusFusarium and the rest to different systematic groups. One hundred and fifty two cultures were antibiotically active; 80% of these were antagonists ofBacillus subtilis, 55% ofEscherichia coli, 20% ofSaccharomyces cerevisiae and 37% ofCandida pseudotropicalis. In agreement with previous observations it was found that the activity spectrum of antagonists was related to the altitude above sea level at which they were found. As the altitude increased, the incidence of antagonists with both antibacterial and antifungal activity decreased, but the incidence of antagonists with only antibacterial or only antifungal activity increased. Fungi of the generaPenicillium andAspergillus were the most frequent antibiotic producers. The incidence of penicillin producers was much lower than in collections of fungi isolated in higher latitudes (China, Bulgaria, Slovakia).     

Distribution of <Emphasis Type="Italic">Divo</Emphasis> in <Emphasis Type="Italic">Coffea</Emphasis> genomes,a poorly described family of angiosperm LTR-Retrotransposons

Coffea arabica (the Arabica coffee) is an allotetraploid species originating from a recent hybridization between two diploid species: C. canephora and C. eugenioides. Transposable elements can drive structural and functional variation during the process of hybridization and allopolyploid formation in plants. To learn more about the evolution of the C. arabica genome, we characterized and studied a new Copia LTR-Retrotransposon (LTR-RT) family in diploid and allotetraploid Coffea genomes called Divo. It is a complete and relatively compact LTR-RT element (~5 kb), carrying typical Gag and Pol Copia type domains. Reverse Trancriptase (RT) domain-based phylogeny demonstrated that Divo is a new and well-supported family in the Bianca lineage, but strictly restricted to dicotyledonous species. In C. canephora, Divo is expressed and showed a genomic distribution along gene rich and gene poor regions. The copy number, the molecular estimation of insertion time and the analysis at orthologous locations of insertions in diploid and allotetraploid coffee genomes suggest that Divo underwent a different and recent transposition activity in C. arabica and C. canephora when compared to C. eugenioides. The analysis of this novel LTR-RT family represents an important step toward uncovering the genome structure and evolution of C. arabica allotetraploid genome.     

Vernonia georgiana—Species or hybrid?

Vernonia georgiana Bartlett was demonstrated to be of hybrid origin by means of hybridization experiments and comparisons of the artificial F₁ hybrids with herbarium specimens ofV. georgiana. The two parental species areV. angustifolia Michx. andV. acaulis (Walt.) Gleason.     

Isolation and characterization of arsenic resistant bacteria from tannery wastes and agricultural soils in Thailand

Highly arsenic resistant bacteria (27 isolates), which had a minimum inhibitory concentrations (MICs) for arsenite and arsenate of ? 40 mM and > 400 mM, respectively, were isolated from tannery wastes and agricultural soils collected in Central Thailand. On the basis of the morphological, cultural, physiological and biochemical characteristics, and on the principal ubiquinone component and 16S rRNA gene sequence analyses, they were identified as nine isolates each ofKlebsiella (Groups 1 and 8) andAcinetobacter (Groups 2, 3 and 7), four isolates each ofPseudomonas (Groups 4 and 6) andComamonas (Group 5), and one isolate ofEnterobacter (Group 9). From these 27 isolates, only one isolate, A3-3 from the genusComamonas, appeared potentially capable of oxidizing arsenite to arsenate, as determined by silver nitrate staining of arsenite agar plates after colony growth.     

Hybridization and regional variation in Pacific Northwestern Impatiens (Balsaminaceae)

Variation patterns ofImpatiens species in the Pacific Northwest are discussed. Much of the variability there is attributed to widespread interspecific hybridization. Taxonomy of the genus is briefly reviewed, and it is suggested that four species should be recognized for the region. An account of natural hybridization betweenI. capensis andI. ecalcarata is given in detail, and it is postulated that the effects of this hybridization may extend beyond the immediate area in which it is detectable on the basis of morphological patterns. It is suggested thatI. aurella may be of hybrid origin since it combines characters of two species in the Pacific Northwest. Although natural hybridization is occurring at the present time, geographical distribution of variant populations of the species suggests that extensive hybridization may have been initiated in late Pleistocene as a result of the ecological disturbances prevalent at that time.     

On the taxonomy ofPuccinia sieversiae Arth. and some remarks on the phylogeny of the rusts onGeeae

Puccinia tatrensis Urban onGeum reptans in Czechoslovakia is recognized as a subspecies ofPuccinia sieversiae Arth.Puccinia waldsteiniae, P. gei andP. gei-parviflori appear to be the most ancient rusts known on the tribeGeeae and it is assumed that their common ancestral form was already present in the Cretaceous period.Puccinia sieversiae is more advanced and has its centre of origin and spread in Central Asia. Phylogenetically most advanced and at the same time most differentiated from each other are species ofPhragmidium, i.e.P. circumvallatum andP. miyabeanum.     

Kearnemalvastrum,a new genus of Malvaceae

Reevaluation of the generic limits ofMalvastrum A. Gray requires the transfer of several species. Among these,M. lacteum (Ait.) Garcke andM. subtriflorum (Lag.) Hemsley of Central America and Colombia form a natural alliance differing fromMalvastrum in morphological, cytological, and ecological characteristics and are recognized as a new genus,Kearnemalvastrum. The affinities ofKearnemalvastrum within the tribe Malveae are uncertain. Despite the fact thatK. lacteum andK. subtriflorum occupy similar ecological situations, are fully interfertile, and apparently hybridize to some degree in nature, they do maintain their identity and, therefore, are recognized as species.     

Evidence from trichome morphology of interspecific hybridization in Vernoma: Compositae

Two types of foliar trichomes, both T-shaped with a uniseriate stalk and a single transverse cell, are used to document natural hybridization betweenVernonia lindheimeri Engelm. & Gray andV. interior Small in central Texas. The putative hybrid, known asV. guadalupensis Heller, has the same type of foliar trichomes but their stalks are neither as long as those ofV. interior nor as short as those ofV. lindheimeri. The transverse cells of the more conspicuous trichome type are also of intermediate size.     

Two new species of Alcantarea (Bromeliaceae,Tillandsioideae) from Brazil

Alcantarea turgida andA. tortuosa are described and illustrated as new species from southeastern Brazil. The relationships ofA. turgida withA. extensa and withA. vinicolor and ofA. tortuosa withA. farneyi and withA. benzingii are discussed.     

Differentiation of species in Gonioloboceras

The type specimen ofGonioloboceras goniolobum (Meek), rediscovered by Spath in the British Museum, is the foundation for a more accurate comparative study of this and other species ofGonioloboceras.Gonioloboceras described asG. goniolobum byElias in 1938 is differentiated asGonioloboceras schmidti, new species. Suture sets (new term) for several growth stages inG. goniolobum (Meek),G. welleriSmith,G. schmidtiElias, G.eliasiMiller &Owen, andG. asiaticumLibrovitch are assembled and used for differentiation of the species.The Kazakhstan goniatite faunule containingG. asiaticum is considered of very late Pennsylvanian age.     

An analysis of hybridization in Liatris

Liatris aspera andL. spicata are remotely related species, and rarely have an opportunity to hybridize because of different flowering periods and ecological tolerances. Seasonal and ecological barriers have been surmounted in a population in southern Cook County, Illinois, which has resulted in extensive hybridization. The population was characterized on the basis of morphological and chemical features, pollen fertility, and chromosome pairing relationships. Plants considered to be F₁ hybrids on the basis of morphology typically displayed the phenolic markers of both parental species, reduced fertility, and meiotic irregularities in the form of univalents and translocation figures. Plants judged to be backcrosses toL. aspera contained some of the phenolics ofL. spicata; however, backcrosses toL. spicata invariably lacked the phenolics ofL. aspera. The species-species phenolics ofL. aspera were inherited as a block, i.e., a hybrid had all or none of these compounds. The complex pattern of gene exchange within the population reflects the weakness of crossing and fertility barriers to hybridization.     

Supplementary notes on American Labiatae. X

Notes on the taxonomy and distribution of various species of Labiatae of Mexico, and Central and South America, are presented, as part of a continuing series of supplements to the authors’ earlier monographs. Eight new species are described in the generaHyptis, Salvia, Satureja, andScutellaria. Two new combinations are made, one each inHarlanlewisia andSatureja. A key and revision are given for the six species ofLepechinia sect.Parviflorae.