The genusCandida berkhout

The authors attempted to classify a group of five strains excluded in typing of the speciesCandida albicans (Robin) Berkhout because they displayed a relationship toCandida tropicalis (Cast.) Berkhout. They were found to include transitional forms showing progressive development to a higher type. Strain 29-3-32 formed a lower stage of transition fromCandida albicans toCandida tropicalis and was more similar toCandida albicans. Strain 29-3-58 formed a higher transitional stage and was more similar toCandida tropicalis. Strain 29-3-5 was similar toCandida albicans and formed the transition from the latter to strain 29-3-100, which was closely related toCandida intermedia andCandida tropicalis. Strain 29-3-68 formed the transition fromCandida guilliermondii toCandida intermedia and was similar toCandida guilliermondii and the related speciesCandida melibiosi.     

NewLiparis species (Orchidaceae) from South Central and East Africa

Liparis molendinacea is related toL. deistelii and known so far only from the type locality in Kawambwa district in the Northern Province of Zambia.L. nyikana likewise is related toL. deistelii, it is distributed in E. and SW. Tanzania and in N. Malawi.L. chimanimaniensis is related toL. nervosa and known so far only from the Chimanimani Mountains in the Eastern Province of Zimbabwe.     

Systematic position of the genusCicer L. (Fabaceae) from data on DNA/DNA hybridization

This investigation was carried out in an attempt to determine the systematic position ofCicer via DNA/DNA hybridization. The data showed that members of the tribeVicieae were related toCicer than toTrifolium andOnonis. It is also showed thatPisum was the nearest species toCicer. Thus, the data presented in this work recommend the classification ofCicer underVicieae rather than a separate tribeCicerideae.     

Acht neue Arten der GattungDianthus (Caryophyllaceae) aus dem Gebiet der Flora Iranica

Dianthus nangarharicus sp. n. (sect.Leiopetali) from E. Afghanistan;D. harrissii sp. n. (sect.Dentati) from N. Pakistan to W. Tibet,D. hyrcanicus sp. n. (sect.Dentati) from N. Iran. Five further new species from Iran belong to sect.Fimbriati:D. binaludensis (close toD. paghmanicus),D. jacobsii (close toD. crinitus andD. orientalis),D. longivaginatus (similar toD. fragrans),D. mazanderanicus andD. agrostolepis (both close toD. orientalis subsp.Gorganicus).     

Parmelia pustulifera,a new lichen from southeastern United States

A new species inParmelia subgenusParmelia sect.Hypotrachyna,P. pustulifera, is described from southeastern United States. It is similar in chemistry and fine structure of the cortex toP. livida Taylor and in gross morphology toP. formosana Zahlbr.     

A new species and a new combination in western North American Silene (Caryophyllaceae)

Silene nachlingerae is described, illustrated, and compared toS. aperta. The similarly floweredS. invisa is considered to be closely related toS. bernardina, and especially to its var.rigidula (Robinson) Tiehm, comb nov.     

A MOLECULAR APPROACH TO THE CIRCUMSCRIPTION AND EVALUATION OF SOME GENERA SEGREGATED FROMPARMELIAS. LAT.

New sequences have been produced of the ITS rDNA region of twenty-nine species ofParmeliaceae, and analysed by neighbour-joining maximum likelihood distance analysis, and maximum parsimony analysis. Twelve monophyletic groups have been identified, most of which correspond to proposed generic segregated fromParmelias. lat.ParmeliaandParmelina,Melanelia, andPuncteliaappear as independent monophyletic groups; the type species of the two latter genera were, however, not included in the analysis. The parsimony analysis does not supportXanthoparmeliaas a monophyletic group separate fromNeofuscelia, andRimelia reticulatais nested withinParmotrema. Parmelinopsis horrescensis more closely related toHypotrachyna revolutathan toParmelina. Genetic distance values suggest thatFlavoparmelia caperatais closer toParmotremathan to other taxa included, and thatPlatismatia glaucaandHypogymnia tubulosaare closer toParmelias. lat. than to thePhysciaceae. However, there is no conclusive support for any of the latter groupings in the parsimony analysis. We conclude that the ITS region contains valuable information for studying generic delimitations within the familyParmeliaceae, but our study suggests that this region will not conclusively resolve within-family relationships in this group.     

A new species ofAphidius [Hymenoptera] attacking the pea aphid,Acyrthosiphon pisum

Aphidius staryi Chen & Luhman n. sp. is described. The species was collected and introduced into California from Israel and Turkey byD. González. The new species is morphologically most similar toAphidius smithi, and keys toEady's urticae group.     

A microbiological assay for sterigmatocystin,T-2 toxin and zearalenone

A survey was done to find microorganisms useful for assaying sterigmatocystin; T-2 toxin and zearalenone.Staphylococcus aureus was found to be sensitive to T-2 toxin and zearalenone;Bacillus cereus was found to be sensitive to T-2 toxin only; andEscherichia coli was sensitive to sterigmatocystin. The response of the organisms to sterigmatocystin; T-2 toxin and zearalenone was found to be linear between 4 and 100 μg with sterigmatocystin toE. coli; between 2 and 25 μg with T-2 toxin toStaph, aureus andB. cereus; and between 4 and 100 μg with zearalenone toStaph, aureus. The lower limits of sensitivity of the test were 2 μg T-2 toxin and zearalenone, and 4 μg sterigmatocystin. The assay is rapid (15–17 hrs); simple and inexpensive; and can be used to verify the toxicity of samples and to confirm thin layer chromatographic results.     

Host specificity of phytophagous organisms and the evolutionary centres of plant genera or sub-genera

Chondrilla juncea is an important weed in Australia. The morphology, ecology and chromosome number of species of the genusChondrilla indicate that the generic centre of evolution is in southern. Bussia and that dispersal has occurred westwards, as far as western Europe, with a reduction in the number ofChondrilla species. The number of organisms specific toChondrilla also increases as one approaches the generic centre of evolution. Therefore, to discover the greatest number of specific, biological control organisms for a weed, surveys should commence initially at its generic evolutionary centre. The application of this principle to genera of other important Australian weeds, namely toEchium which has two evolutionary centres and toHeliotropium which has a number of sub-generic evolutionary centres is discussed.     

Novelties in Chamaecrista section Absus (Caesalpiniaceae)

Described, figured and discussed are two new species ofChamaecrista sect.Absus from campo rupestre habitats in southeastern Brazil:Ch. axiliflora Irwin & Barneby, of seriesAdenophyllae, from central Bahia, related toCh. adenophylla (Taubert) Irwin & Barneby; andCh. gumminans Irwin & Barneby, of seriesGlutinosae, from central Minas Gerais, related toCh. stilifera Irwin & Barneby.     

Salenioid Echinoids from the Maastrichtian (Upper Cretaceous) of Belgium and The Netherlands

The Salenioid echinoids in the Royal Belgian Institute for Natural Sciences, from the Belgian and Dutch Maastrichtian (Upper Cretaceous) are systematically revised. Three species belonging toSalenidia, and three belonging toSalenia are redefined. One new species(Salenidia sanctipetri) is named and described.Salenidia maestrichtensis is represented by many specimens of all ages, allowing morphological variation, to be traced during growth.     

Comparison ofEnt-kaurene synthetase A and B activities in cell-free extracts from young tomato fruits of wild-type andgib-1, gib-2, andgib-3 tomato plants

The nonallelicgib-1 andgib-3 tomato (Lycopersion esculentum Mill.) mutants are gibberellin deficient and exhibit a dwarfed growth habit. Previous work has shown that this dwarfed growth pattern can be reversed by the application of a number of gibberellins and their precursors, includingent-kaurene (ent-kaur-16-ene). This indicates that they are blocked in gibberellin biosynthesis at a step prior toent-kaurene metabolism. The normal accumulation of carotenoids observed in these mutants suggests a functionally normal isoprenoid pathway.Ent-kaurene is synthesized from geranylgeranyl pyrophosphate in a two-step process with copalyl pyrophosphate as an intermediate.In vitro assays using young fruit extracts from wild-type andgib-2 plants resulted in the conversion of geranylgeranyl pyrophosphate to copalyl pyrophosphate, and the conversion of copalyl pyrophosphate toentkaurene. Similar assays usinggib-1 plants indicated a reduced ability for synthesis of copalyl pyrophosphate from geranylgeranyl pyrophosphate, and thus a reducedent-kaurene synthetase A activity. Furthermore,gib-3 extracts demonstrated a reduced ability to synthesizeent-kaurene from copalyl pyrophosphate, and thus a reducedent-kaurene synthetase B activity. These results establish the enzymatic conversion of geranylgeranyl pyrophosphate to copalyl pyrophosphate, and copalyl pyrophosphate toent-kaurene, as the sites of the mutations ingib-1 andgib-3 tomatoes, respectively. We also note that tomato fruit extracts contain components which are inhibitory toent-kaurene synthesis.     

The effects of neighbors on the growth and survival of shrub seedlings following fire

Where plant species vie for limited resources, disturbances might preclude competition by releasing a flush of nutrients, or by reducing biomass and thereby diminishing the consumption of resources. However, if new seedlings colonize in clumps, they may still deplete resources within the local aggregations, which may then reduce their growth and survivorship. We investigated competition among seedlings in a burned area by examining the relationship between the performance of newly established shrub seedlings of Ceanothus impressus and (1) the proximity and (2) the identity of their near neighbors. We also investigated the relationship between neighbor proximity and the availability of water. Both survivorship and growth of C. impressus were positively associated with increasing distance to near neighbors, in a manner consistent with resource competition. The availability of water (as determined by pre-dawn xylem pressure potentials) tended to be greater when neighbors were farther away, providing evidence that water was a resource for which plants were competing. This conclusion is reinforced by the finding that the effects of neighbors were stronger in drought years, suggesting that yearly variation in the availability of an important resource (water) can affect the strength of competitive interactions. This suggests that after disturbances, when some resources are apparently abundant on a large scale, competition may be important in determining the small scale patterns of seedling growth and survival.     

Myocardial KChIP2 Expression in Guinea Pig Resolves an Expanded Electrophysiologic Role

Cardiac ion channels and their respective accessory subunits are critical in maintaining proper electrical activity of the heart. Studies have indicated that the K⁺ channel interacting protein 2 (KChIP2), originally identified as an auxiliary subunit for the channel Kv4, a component of the transient outward K⁺ channel (I_to), is a Ca²⁺ binding protein whose regulatory function does not appear restricted to Kv4 modulation. Indeed, the guinea pig myocardium does not express Kv4, yet we show that it still maintains expression of KChIP2, suggesting roles for KChIP2 beyond this canonical auxiliary interaction with Kv4 to modulate I_to. In this study, we capitalize on the guinea pig as a system for investigating how KChIP2 influences the cardiac action potential, independent of effects otherwise attributed to I_to, given the endogenous absence of the current in this species. By performing whole cell patch clamp recordings on isolated adult guinea pig myocytes, we observe that knock down of KChIP2 significantly prolongs the cardiac action potential. This prolongation was not attributed to compromised repolarizing currents, as I_Kr and I_Ks were unchanged, but was the result of enhanced L-type Ca²⁺ current due to an increase in Cav1.2 protein. In addition, cells with reduced KChIP2 also displayed lowered I_Na from reduced Nav1.5 protein. Historically, rodent models have been used to investigate the role of KChIP2, where dramatic changes to the primary repolarizing current I_to may mask more subtle effects of KChIP2. Evaluation in the guinea pig where I_to is absent, has unveiled additional functions for KChIP2 beyond its canonical regulation of I_to, which defines KChIP2 as a master regulator of cardiac repolarization and depolarization.     

Zoophthora phytonomi andConidiobolus osmodes [Zygomycetes:Entomophthoraceae], two pathogens ofHypera species [Col.: Curculionidae] coincidental in time and place

Two entomophthoraceous species, found at different localities in Israel, caused epizootics onHypera variabilis Herbst. larvae during spring of 1976 and 1977.Zoophthora phytonomi (Arthur) Batko, emend.Ben-Ze’ev & Kenneth (syn.Entomophthora phytonomi Arthur) produced in the field only conidia, whereasConidiobolus osmodes Drechsler formed only dark, rough-walled resting spores that had been erroneously thought in the past to belong toZ. phytonomi. In culture,Z. phytonomi, isolated from conidia, produced subhyaline, smooth resting spores, whereasC. osmodes from resting spores produced rotund conidia, which proved pathogenic toH. variabilis larvae and adult houseflies. All species connected by different authors withZ. phytonomi are discussed, includingE. elateridiphaga, transferred here toZoophthora.     

A numerical study of the common narrow-leaved taxa of chenopodium occurring in the Western United States

A numerical taxonomic study was conducted on the common narrow-leaved members of the genusChenopodium that occur in the western United States. As many as six and as few as two species have been recognized. Thirty-five individual popu lations were used as OTU’s, and 35 characters were considered. The data were subjected to cluster (both the weighted-pair group method and the within-group dispersion method) and principal component analysis. The results of both analyses are in general agreement and suggest phenetic relationships that differ from current interpretations in the literature. It is concluded thatC. desiccatum var.leptophylloides is much more closely related phenetically toC. atrovirens (and may not be distinct from it) than it is toC. desiccatum var.desiccatum. Chenopodium hians andC. leptophyllum appear to be phenetically distinct despite the fact that they have sometimes been viewed as conspecific.Cheno podium subglabrum is not very similar toC. leptophyllum, and should probably be treated as a separate species rather than as a variety of the latter. Popu lations referable toC. incognitum form a rather loose cluster that appears some what intermediate between populations ofC. desiccatum var.leptophylloides,C. atrovirens, C. hians, andC. leptophyllum.     

Three new species of Phacelia (Hydrophyllaceae) from Nuevo León,Mexico

Three new species ofPhacelia from Nuevo León, Mexico are described and illustrated. Two of these,P. hintoniorum andP. potosina, belong to theCrenulata group; the former, with included anthers, relates toP. coerulea; the latter, with exserted anthers, relates toP. alba orP. coulteri. The remaining novelty,P. zaragozana, belongs to the subgenusCosmanthus where its closest relationship is withP. laxa.