Reproductive biology of five native plant species from the Monte Desert of Argentina

Research into plant breeding systems enables the evaluation of whether seed production depends on pollination agents and gene flow mechanisms within and among populations. This aids, in turn, the estimation of the appropriate population sizes needed to maintain both genetic and species' diversity. Little is known about plant reproductive biology in the Monte Desert (Patagonia, Argentina), a habitat threatened by desertification as a result of human impact. The mating systems, flowering phenologies and pollinator networks were studied in five representative plant species of the Monte Desert. The mating systems studied ranged from anemophilous pollen dispersion in the dioecious Atriplex lampa, to a gradient of dependence on pollinators, from the less dependent (facultative self‐compatible) Gutierrezia solbrigii and two Larrea spp. (L. divaricata and L. cuneifolia) to the most dependent Grindelia chiloensis (self‐incompatible). Flowering phenology was restricted to spring and coincided with pollinator abundance. Solitary bees were the main pollinator group, but beetles, flies and butterflies were also important. The four insect‐pollinated species were moderately generalist, but they maintained their own pollinator assemblage. Coleopterans depended more on Grindelia chiloensis and dipterans on Gutierrezia solbrigii. Lepidopterans frequently visited Gutierrezia solbrigii and Larrea divaricata, whereas hymenopterans visited both Larrea spp. more frequently. The studied plant species are ecologically important, not only as resources for a wide range of pollinator species but also for other insects. The Monte Desert is a very disturbance‐sensitive environment and, as these plant species hardly show vegetative regeneration, sexual reproduction is essential for their survival. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161 , 190–201.     

Palynotaxonomy of Brazilian species of Polygala subgenus Hebeclada

This study used pollen morphology to address taxonomic controversies related to several species belonging to subgenus Hebeclada of the genus Polygala (Polygalaceae). According to the last traditionally accepted revision of this subgenus, it comprises 40 species. Nevertheless, a recent taxonomic treatment applying more comprehensive criteria reduced this number to only nine species. Our work focused on 15 traditionally accepted species that occur in Brazil, fourteen of which have been considered as only six species in this recent taxonomic study. Pollen grains from floral buds at pre‐anthesis were collected from herbarium specimens and analysed using both visible light and scanning electron microscopy. Most of the traditionally accepted species were distinguished by different combinations of several pollen‐related features, in particular colpi number (13 or 15), pollen size and shape, and endoaperture type (endocingulate or not) and arrangement (parallel or sinuous). The species accepted in the recent taxonomic treatment could not be discriminated by pollen characters. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 609–619.     

POTENCY OF SWEETNESS OF ASPARTAME, D-TRYPTOPHAN AND THAUMATIN EVALUATED BY SINGLE VALUE AND TIME-INTENSITY MEASUREMENTS

Perceived sweetness of sucrose, aspartame, D-tryptophan and thaumatin in a sour, citric acid background was analyzed in terms of the potency of these compounds relative to sucrose-water combinations. Potencies of the sweeteners were determined from (1) maximum intensity using single value and time-intensity (T-I) measurements and (2) average intensity calculated as the ratio of area under the T-I curve and total perceived time. Stevens' law was applied to sweet responses, either in static or dynamic conditions. It was found that the exponent of the concentration-response function reflected the relative capacity of a compound to sweeten a given food and stressed differences of potency among sweeteners. Aspartame, D-tryptophan and thaumatin exhibited a decrease in sweetness potency relative to sucrose as sweetness increased from 10 to 100% of the full scale of response. Across the entire sweetness range, thaumatin showed the greatest potency but its long persistence time led to differentiate this intense sweetener from the other sweeteners evaluated.     

Phylogenetic relationships within Diplotaxini Kirby (Coleoptera: Melolonthidae: Melolonthinae) with emphasis on Liogenys Guérin‐Méneville

Diplotaxini Kirby is one of the 29 tribes of Melolonthinae with Nearctic, Neotropical, Paleartic, Afrotropical and Oriental distribution. According to the current classification, Diplotaxini is composed of 706 species described in 21 genera. Neotropical Diplotaxini comprise 94 species, of which 78 are members of Liogenys Guérin Méneville, the largest Neotropical genus. Until now, no phylogenetic studies on Diplotaxini have tested whether the tribe is natural or artificial. This study tested the relationships among Diplotaxini genera, created hypotheses for better defining them, and assessed the monophyly of Liogenys. Cladistic analyses using 167 adult morphological characters were performed. The 83 included taxa represent three subfamilies of Melolonthidae, four tribes of Melolonthinae, and most genera of Diplotaxini, with emphasis on Liogenys. The data were analysed using parsimony under equal and implied weights. In both analyses, the traditional concept of Diplotaxini is shown to be a polyphyletic assemblage. Empecta Erichson and Clypeasta Fairmaire are closely related to Melolontha melolontha (Linnaeus) and Pseudoliogenys Moser close to Myloxenoides Martínez (Tanyproctini). Pachrodema Blanchard is identified as the sister group of Liogenys. The monophyly of both Pacuvia Curtis and Homalochilus Blanchard is confirmed and the paraphyly of Diplotaxis Kirby is suggested. The analyses strongly supported the polyphyly of Liogenys. To render this genus monophyletic, we transferred L. ferrugata Mannerheim (related to M. melolontha) to Phyllophaga Harris, and L. micropyga Burmeister to Diplotaxis, forming Diplotaxis micropyga (Burmeister, 1855) comb.n. ; and included Homoliogenys tarsalis (Moser) and Hilarianus anguliceps Blanchard in Liogenys. As H. anguliceps is syn. junior of Liogenys punctaticollis, Hilarianus is synonymized with Liogenys. Hilarianus ovalis and Hilarianus rufinus are here assigned to Manonychus, and Hilarianus uniformis and Hilarianus suboblongus to Blepharotoma, forming: Blepharotoma uniformis comb.n. , Blepharotoma suboblongus comb.n. , Manonychus ovalis comb.n. and Manonychus rufinus comb.n.     

Amphotericin B-Induced Carbohydrate Changes on the Trypanosoma cruzi Surface Membrane

ABSTRACT Changes in the cell surface carbohydrates of Trypanosoma cruzi epimastigotes induced by Amphotericin B (AmB) were assessed by chemical methods and by agglutination assay employing a panel of highly purified lectins of various sugar specificities, Escherichia coli K12 with mannose-sensitive fimbriae was also used as an agglutination probe. Amphotericin B caused a decrease in the total carbohydrate content of all glycoconjugate fractions isolated. Exposure to AmB strongly affected the mannose/galactose ratio (1:5) in the CHCI3/methanol/H2O soluble fraction. These sugars in 1.4:1 ratio were the major hexose components of control cells. The decrease in the mannose content (48 to 15%) after AmB treatment agrees with the marked decrease in the T. cruzi cell surface receptors for fimbriated E. coli K12. Also, an increase in the galactose content (74%) as compared with control cells (34%) is in agreement with the peanut agglutinin and Euonymus europaeus lectins agglutination results. Differences in the cell surface carbohydrates induced by AmB could be associated with alterations in the membrane structure and organization.     

Traditional and New Cable Restraint Systems to Capture Fox in Central Spain

ABSTRACT Capturing animals is an essential tool of wildlife management, but the use of capture devices is being affected by public pressures on an international scale. In Europe, and particularly Spain, foxes (Vulpes vulpes) are often captured using traditional methods such as nonlocking Spanish Snares (SS) set in an ad hoc fence line known as an alar, but these traditional European methods are rarely compared to modernly described restraints such as the Wisconsin Cable Restraint (WR). We evaluated rates of efficiency, selectivity, injury, and impacts to foxes and nontarget species when using SS (as traditionally set in an alar) or WR within alars or on trails in Castilla-La Mancha, Spain. During 40,372 trap-nights from summer to winter of 2007, we captured 64 foxes, and 8 of 23 potential nontarget species. Our results indicated that WR set in trails were more efficient (0.28 capture rate) for capturing red foxes than SS set in an alar (0.11 capture rate). Relative to injury, foxes captured with the WR in the alar (95.4%), and WR in trails (90.5%), and the SS (90.9%) showed no indicators of poor welfare, and injury score analysis indicated that injuries were of similar magnitude for all capture devices. Overall, the WR set in trails may have performed the best, but all 3 methods are likely sufficient for capturing foxes with minimal injury, acceptable efficiency, and acceptable impact to foxes and sympatric nontarget species. Thus, wildlife managers in Spain and elsewhere can apply our findings to optimize capture and management of foxes.