Phylogenetics of Asphodelaceae (Asparagales): An Analysis of Plastid rbcL and trnL-F DNA Sequences

Phylogenetic relationships of Asphodelaceae were investigatedby parsimony analysis of 57 monocotrbcL nucleotide sequences,including 17 genera that have at some time been assigned tothe family. All genera of Asphodelaceae except for three (Hemiphylacus,Paradisea and Simethis) form a strongly supported monophyleticgroup with Hemerocallidaceae and Xanthorrhoeaceae as their immediatesister taxa. In a second analysis, we added 34 plastid trnL-Fsequences (an intron and a spacer between two transfer RNA genes)for the Asphodelaceae clade and nearest outgroup families (Doryanthaceae,Hemerocallidaceae, Iridaceae, Ixioliriaceae, Tecophilaeaceaeand Xanthorrhoeaceae) in an attempt to improve resolution andlevels of internal support. The results from the separate analysesproduced highly similar although not identical results. No stronglysupported incongruent groups occurred, and we combined bothsequence regions in one analysis, which demonstrated improvedresults. Strong support exists for a monophyletic subfamilyAlooideae, but this leaves a paraphyletic subfamily Asphodeloideaebecause Bulbine/Jodrellia alone are strongly supported as thesister group of Alooideae. Characters that have been used toseparate Alooideae as a distinct group (either as here a subfamilyor as a separate family by other authors), such as secondarygrowth and bimodal karyotypes, are found in at least some membersof Asphodeloideae, particularly in Bulbine and Jodrellia forthe karyotypes, making Alooideae less easily recognized. Copyright2000 Annals of Botany Company Alooideae, Asphodeloideae, Asphodelaceae, Asparagales, phylogenetic analysis, rbcL, trnL-F, molecular systematics     

Isolation of a Tobacco cDNA Encoding Sar1 GTPase and Analysis of Its Dominant Mutations in Vesicular Traffic Using a Yeast Complementation System

The cDNA clone of NtSARl, a gene encoding the small GTPase Sar1pwhich is essential for vesicle formation from the endoplasmicreticulum (ER) membrane in yeast, has been isolated from Nicotianatabacum BY-2 cells. NtSAR1 as well as AtSAR1 cDNA isolated fromArabidopsis thaliana [d'Enfert et al. (1992) EMBO J. 11: 4205]could complement the lethality of the disruption of SARI inyeast cells in a temperature-sensitive fashion. They also suppressedyeast sec12 and sec16 temperature-sensitive mutations as yeastSARI does. Using this complementation system, we analyzed thephenotypes of several mutations in plant SAR1 cDNAs in yeastcells. The expression of NtSAR1 H74L and AtSAR1 N129I showeddominant negative effect in growth over the wild-type SARI,which was accompanied by the arrest of ER-to-Golgi transport.Such dominant mutations will be useful to analyze the role ofmembrane trafficking in plant cells, if their expression canbe regulated conditionally. (Received October 29, 1997; Accepted March 17, 1998)     

Biomechanical Attributes of the Leaves of Pine Species

The flexural stiffness EI, elastic modulus E, second momentof area I, length L, and weight Wt of foliage leaves from 26species of pine were measured to determine the manner in whichEI is scaled to leaf size (L or Wt, or both) and to determineif the biomechanical attributes of foliage leaves could be juxtaposedwith the systematic affiliations of species within Pinus Biomechamcaland morphometric data were explored based on a model from engineeringtheory that predicts the relationships among EI, Wt and L providedthat the maximum tip-deflection _max of an untapered cantileveredbeam sustaining its own weight is maintained as the beam eitherincreases in length or weight, or both, I e _max = Wt L²/8EIThe data show that EI disproportionately increased as eitherWt or L, or both increased The allometry of leaves did not conformto that predicted by the model Rather, EI was proportional tothe product of Wt and L raised to an exponent slightly greaterthan one Thus, Omax was predicted not to be maintained as eitherWt or L, or both, increased, as verified by observations Therelationship between El and Wt(L) differed for species typicallyproducing two leaves per fascicle and those bearing more thantwo leaves per fascicle Also, El is geometrically constrainedby the number of leaves produced per fascicle, principally interms of the effects of the number of leaves per fascicle onI Pinus, pine, leaves, biomechanics, Young's modulus     

The Identification of the Seeds and Achenes of the British Plantaginaceae

The morphology of seeds and achenes of the British members ofthe Plantaginaceae has been examined. Keys to the identificationof seeds in the genera Plantago and Littorella are presented.Quantitative data on size and weight, as well as informationabout shape, colour and surface features of the seeds are givenfor: Plantago major L., P. media L., P. lanceolata L., P. martimaL., P. coronopus L., P. indica L., P. sempervirens Crantz, andLittorella uniflora (L.) Aschers. A representative sample ofeach seed is illustrated.     

Nucleotide Sequence and Features of the Bacillus licheniformis gnt Operon

Bacillus licheniformis was able to utilize gluconate as thesole carbon source as efficiently as Bacillus subtilis did.Southern analysis indicated that B. licheniformis likely possessesonly one gnt determinant. The nucleotide sequence (6278 bp)of the B. licheniformis DNA containing the gnt operon was determined,revealing the five complete open reading frames (ORF; genes).The putative product of the first gene, oug, did not show anysignificant homology to known proteins, but those of the secondto fifth genes exhibited striking homology to the gntRKPZ genesof B. subtilis, respectively, indicating that they are the correspondinggnt genes of B. licheniformis. Not only is the organizationof the gnt genes of these two Bacilli highly conserved, butso are the cis regulatory elements of their gnt operon. Sequenceanalysis of the upstream regions of these two gnt operons impliedthat a chromosome rearrangement in B. subtilis might have occurredimmediately upstream of the gnt operon during evolution, causingit to diverge from a common ancestor into B. licheniformis andB. subtilis.     

The Identification of the Seeds of the British Papaveraceae

The morphology of seeds of British wild, introduced, and commonlycultivated members of the Papaveraceae has been examined, anda key to the identification of the seeds is presented. Quantitative data on size and weight as well as informationabout shape, colour and surface features of the seeds are givenfor Papaver rhoeas L., P. dubium L., P. lecoqii lamotte, P.hybridum L., P. argemone L., P. somniferum L., P. lateritiumC. Koch, P. atlanticum (Ball) Coss., P. orientale L., P. nudicauleL., Meconopsis cambrica (L.) Vig., M. betonicifolia French,Roemeria hybrida (L.) DC., Glaucium flavum Crantz., G. corniculatum(L.) Rudolph, Chelidonium majus L., Eschscholzia californicaCham., E. erecta cv. compacta and E. erecta cv. miniature. Arepresentative sample of each seed is illustrated.     

Effects of Olisthodiscus luteus on the feeding and reproduction of the marine rotifer Synchaeta cecilia

The chrysophyte Olisthodiscus luteus is not ingested by Synchaetacecilia. It inhibits the feeding on other, acceptable food atO. luteus densities as low as 50 cells ml^–1 and reducessurvival and reproduction at O. luteus densities > 10³ cellsml^–1. The possible mechanisms and implications of thisphenomenon for the distribution and abundance of S. ceciliaare discussed.     

Structural analysis of winter phytoplankton in the Gulf of Naples

Quantitative and qualitative distribution of surface phytoplankton,as related to hydrographic conditions, was studied in the Gulfof Naples in February 1979. Previous work has shown that the Gulf of Naples is a diversifiedecosystem, due to geographic and hydrographic features as wellas man made eutrophication, that can be subdivided into twomajor parts: a coastal subsystem and an open water one. Hydrographic analysis of the winter situation at the surfacefully confirms this picture, as it identifies two distinct watermasses corresponding respectively to surfaced Tyrrhenian IntermediateWater and to Coastal Surface Water. The structural analysisof phytoplankton reveals three assemblages of species characterizingdifferent water types: 1 - the Ischia and Procida channels affectedby the advection of Volturno river and Cuma outfall plumes;2 - the coastal area of the Gulf proper, namely the bays ofPozzuoli, Naples and Castellammare; 3 - the open waterhemislocated beyond the 100 m isobath. The channel area assemblage is dominated by diatoms, particularlyby fast growing species, such as Asterionella japonica, severalspecies of Chaetoceros and Rhizosolenia hebetata f. semispina.The coastal assemblage is identified, among others, by the diatomsCerataulina bergonii, Hemiaulus sinensis; the dinoflagellatesGlenodinium lenticula, Exuviaella compressa and Porella perforata.The open water assemblage is characterized by the diatoms Coscinodiscuscurvatulus and Hemidiscus cuneiformis, the dinoflagellate Amphidiniumacutissimum and the coccolithophore Coccolithus haeckelii.     

Differences in Graft Transmission of the Floral Stimulus in Two Species of Kleinia

Graft transmission of the floral stimulus was studied in homograftsof Kleinia articulata (SDP) and heterografts between K. articulataand K. repens (LSDP). While receptor shoots of K. repens graftedonto induced donor plants of K. articulata flowered readilyin LD (16 h) as well as SD (8 h), graft-induced flowering failedto take place in LD receptors of K. articulata. Neither theinduced shoots and detached leaves from induced plants of K.articulata nor the induced shoots of K. repens could evoke theflowering response in the K. articulata receptors. Increasingthe donor pool of induced leaves even up to ten per receptoralso had no effect. It is known that the very young leaf primordiaof K. articulata are photoperiodically sensitive, and it seemsthat they may prevent the stimulus from reaching the apex. Key words: Kleinia, Flowering stimulus, Graft transmission     

No evidence of Wolbachia among Great Lakes area populations of Daphnia pulex (Crustacea: Cladocera)

Wolbachia endobacteria are commonly associated with a varietyof arthropod species as hosts and induce known changes in theirhosts’ life-history traits. Despite exhibiting severalWolbachia-like life-history traits, and despite being a commonmodel organism, the zooplankton Daphnia pulex has not been formallytested for infection with Wolbachia. Among 203 isolates exhibitinga range of life-history phenotypes, we found no evidence ofWolbachia. This leaves the genes of D. pulex as the most likelycause of its own life-history traits.     

Physical Characterization of the Chromosomal DNA of the Yeast Saccharomyces exiguus

The number of chromosomes in the yeast Saccharomyces exiguuswas determined to be thirteen by two-dimensional pulsed-fieldgel electrophoresis. The thirteen chromosomes ranged in DNAsize from 520 to 2,600 kbp, with a total length of approximately14 Mbp. Numbers I to XIII were assigned to the chromosomes indecreasing order of DNA length. Southern hybridization analysisusing total DNAs from S. exiguus and S. cerevisiae as probesshowed that there was no significant homology between the chromosomalDNAs of the two species, except in the case of the chromosomalDNA that included rDNA. When rDNA and genes LEU2, TRP1, URA3and HO of S. cerevisiae were used as hybridization probes, itwas apparent that S. exiguus had DNA sequences homologous tothe rDNA and to the LEU2 and HO genes. In S. exiguus, rDNA-likeand LEU2-like DNAs were located on chromosomes I and IX, respectively,and HO-like DNA was located on chromosome VI or VII. (Received May 17, 1993; Accepted July 15, 1993)     

Enzymatic Conversion of Pheophorbide a to the Precursor of Pyropheophorbide a in Leaves of Chenopodium album

Soluble proteins extracted from leaves of Chenopodium albumcatalyzed the conversion of pheophorbide a to a precursor ofpyropheophorbide a, putatively identified as C-13²-carboxyl-pyropheophorbidea. The precursor was then decarboxylated non-enzymatically toyield pyropheophorbide a. Soluble proteins and pheophorbidea, as the substrate, were required for the formation of theprecursor, and boiled proteins were enzymatically inactive.The maximum rate of conversion of pheophorbide a to the precursoroccurred at pH 7.5. The K_m for pheophorbide a was 12.5 µMat pH 7.0. Both pheophorbide b and bacteriopheophorbide a couldserve as substrates, but protopheophorbide a could not. Formationof methanol was detected during the enzymatic reaction, an indicationthat the enzyme is an esterase. Among seven alcohol analogstested, only methanol inhibited the enzymatic activity uncompetitively,with a K₁ of 71.6 mM. Mass-spectrometric (MS) analysis of theprecursor yield a peak at m/z 579 that indicated the releaseof a methyl group from pheophorbide a. It appears thereforethat the enzyme catalyzes the demethylation of the carbomethoxygroup at C-13² of pheophorbide a by hydrolysis to yield methanoland the precursor, C-13²-carboxyl-pyropheophorbide a, whichis converted to pyropheophorbide a by spontaneous decarboxylation.We have tentatively designated the enzyme "pheophorbidase".The presence of the enzyme was dependent on plant species andit was expressed constitutively. ¹Present address: Faculty of Science, Shizuoka University, Ohya,Shizuoka, 422 Japan     

Effects of rotifers and ciliates on the growth and survival of Daphnia

Daphnia can suppress ciliates and rotifers through predationand interference competition, but it is not known whether thisproduces any direct benefit to Daphnia. We conducted survivorshipand cohort lifetable experiments to determine whether Daphniacan utilize ciliates and rotifers as food. Three species ofoligotrich ciliates (Halteria grandinella, Strobilidium gyransand Strobilidiumvelox) and one rotifer (Keratella cochlearis)were used. Lifetable experiments were conducted with a basallevel of algae (Cryptomonas sp.), plus either ciliates or rotifers,while survivorship experiments had only the rotifers or ciliates.Densities of 30 H.grandinella ml^–1, 50 S.gyrans ml^–1and 15 S.velox ml^–1 enhanced Daphnia pulex's populationgrowth rate 35–50% over controls with only algae. TenS.gyrans ml^–1 did not produce a significant change inDaphnia's growth rate. Densities of 100 and 300 K.cochlearis^–1 increased Daphnia population growth rates by II and10%, respectively. Both 10 and 50 S.gyrans ml^–1 enhancedDaphnia's survivorship compared to starved controls, but neither100 nor 300 K.cochlearis l^–1 enhanced its survivorship.The amount of enhancement of Daphnia growth rates by rotifersand ciliates is roughly proportional to the death rates imposedby Daphnia. The death rate imposed by Daphnia on rotifers isa function of both algal density and Daphnia size. Per unitbiomass, neither ciliates nor Keratella appear to be as nutritiousfor Daphnia as is Cryptomonas.     

Distribution of the cyanobacterium Richelia intracellularis as an epiphyte of the diatom Chaetoceros compressus in the western Pacific Ocean

The few available records on the association of the diazotrophheterocystous cyanobacterium Richelia intracellularis epiphyticallywith Chaetoceros compressus are restricted to the Indian andwestern Pacific Oceans, whereas the association of R. intracellularisas an endosymbiont in other diatoms is ubiquitous in warm oceans.From ten cruises in the western Pacific Ocean, the Richelia-Chaetocerosconsortia were exclusively observed in the periphery of thegeographic proliferations of C. compressus, coinciding withthe overlapping area of the populations of asymbiotic C. compressusand R. intracellularis as an endosymbiont in Rhizosolenia clevei.     

Macrozooplankton studies in Kuwait Bay (Arabian Gulf). II. Distribution and composition of planktonic penaeidea

Six penaeideans were identified during a 12-month investigationof macrozooplankton in Kuwait Bay. The numerically dominantspecies included two sergestids, Lucifer hanseni and Acetesjaponicus. Of the two, L.hanseni appears to spawn in the bayduring summer months while, A.japonicus may concentrate itsspawning in coastal waters during late spring through fall.The most abundant penaeids were Parapenaeopsis stylifera andMetapenaeus spp., although Kuwait Bay may not be a major spawningarea for these species. However, the Khor al Sabiya, a river-likechannel northeast of Kuwait Bay, may serve as a nursery forat least two of the penaeids (Metapenaeus spp. and Penaeus semisulcatus)as well as for A.japonicus. Both P.stylifera and Metapenaeusspp. larvae were most abundant during late spring. Penaeus semisulcatuslarvae exhibited fall and spring-summer maxima but were neverlocally abundant.     

Interrelationship between Meristematic Regions of Developing Inflorescences of Four Cereal Species

A cultivar from each of four cereal species (Avena sativa L.,cv. Swan, Hordeum vulgare, L., cv. Clipper, Triticum aestivumL., cv. Gabo, and Secale cereale L., cv. South Australian Rye)was grown in controlled environment chambers in a 10-h photoperiod(short days) or 10-h photoperiod supplemented with a 6-h extensionby incandescent light. The developmental morphology of the inflorescenceswas followed to ascertain whether there were any common developmentalinterrelationships between the species. Inflorescence internodeelongation was initiated when the floret initial first appeared,irrespective of whether it occurred on the most advanced lateralspikelet or on the terminal spikelet of the rachis. The glumes(infertile bracts) of the terminal spikelet of the rachis wereinitiated when the first second-order inflorescence branch appeared,irrespective of whether the second-order inflorescence branchwas a floret initial or a lateral spikelet, as in Triticum sp.,or an inflorescence (panicle) branch, as in Avena sp. Cessationof the activity of the apical meristem, as measured by primordiumformation, was not correlated with any particular stage of floraldevelopment but appeared to be due to a lack of nutrients causedby an increasing competitiveness for the available nutrientsfrom the developing spikelets which are situated closer to thevascular system than the apical meristem.     

Effects of environmental factors on ichthyoplankton communities in the Miramichi estuary, Gulf of St Lawrence

Ichthyoplankton in 20 taxa (17 identified to species, threeto genus) representing 14 families were collected in 10 surveysof the Miramichi estuary between May and September 1992. Thetaxonomic composition was typical of other estuaries in theGulf of St Lawrence and Gulf of Maine. Larvae of three anadromousspecies [rainbow smelt (Osmerus mordax), alewife (Alosa pseudoharengus)and blueback herring (Alosa aestivalis)] were several ordersof magnitude more abundant than any other taxon. The upper estuary(Miramichi River and its tributaries) probably serves as a nurseryground for larvae of these species and others such as Atlantictomcod (Microgadus tomcod). The species composition of the lowerestuary (Miramichi Bay) was dominated by typically marine formsand probably serves as a nursery ground for winter flounder(Pleuronectes americanus), smooth flounder (Pleuronectes putnami).sculpin (Myoxocephalus sp ) and sand lance (Ammodytes sp) Ofthe environmental factors investigated, salinity was the mostuseful predictor of larval distribution in the estuary.