A revised classification of subtribe Helianthinae (Asteraceae: Heliantheae). I. Basal lineages

Results for nuclear ITS sequences were combined with previously obtained data from cpDNA restriction site studies to provide a comprehensive molecular phylogeny for subtribe Helianthinae. Results from the two molecular data sets were mostly congruent for basally diverging branches of the subtribe. Based on the results, combined with morphological observations, the basally diverging branches are placed in six genera, including one newly described. Bahiopsis is resurrected to accommodate species previously placed in Viguiera subgenus Bahiopsis . Calanticaria is newly proposed for the five species of Viguiera ser. Brevifolieae . Heliomeris is retained for the group sometimes included within Viguiera as sect. Heliomeris . Hymenostephium is revived and enlarged to include a number of species of similar habit and involucre, including members of Viguiera sect. Diplostichis , Haploca-lymma and Garcilassa . Although cpDNA results place the morphologically distinctive Sclerocarpus within the clade including species of Hymenostephium , the ITS data were consistent with morphology in suggesting it to be a distinctive lineage.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 140 , 65–76.     

Physical mapping of rDNA genes establishes the karyotype of almond

The localisation of ribosomal RNA genes on chromosomes of almond (Prunus amygdalus, 2n = 16) was studied by fluorescence in situ hybridisation. Simultaneous double-colour hybridisation with both 18S–5.8S–25S and 5S rDNA probes demonstrated that all chromosomes can be identified. In spite of the small size, differences in length between chromosomes that hybridised with the same rDNA probe as well as between chromosomes without hybridisation signal are apparent. Chromosomes were ordered in the karyotype according to their length. The 18S-5.8S-25S rDNA genes were detected in subdistal positions of chromosomes 2, 3, and 8. Sites located on chromosomes 2 and 3 carry a higher number of repeats than the site of chromosome 8. The 5S rDNA genes were found proximally located on chromosomes 5 and 7, the signal on chromosome 5 showing higher intensity than the signal on chromosome 7. Chromosomes 1, 4, and 6 show no hybridisation signal.     

Carbon Dioxide and Ammonia Exchange in the Trachypogon Savannas of the Orinoco Llanos

Atmospheric carbon dioxide (CO₂) and ammonia (NH₂) exchangeswere determined in the Trachypogon savannas of the Orinoco Llanosusing the energy balance approach. Total dry mass and separatedry mass values of plant parts were used for a growth analysisof the community and for measurements of nitrogen content. Duringthe growth period, the net assimilation (P₄₀) ranged from 0.102to 0.127 MJ m^–2 d^–1 (6.6–7.9 g dry mass m^–2d^–1). These figures were similar to mean crop growth ratemeasured using the mass balance approach (2.8–6.9 g drymass m^–2 d^–1). Analysis of the daily trend of theCO₂ assimilated by the community showed a low total energy conversionof net photosynthesis (_x = 0.7) compared with the values reportedfor tropical grasses. During the dry season, the community conserved71% of the maximum N accumulated during the previous wet season.Sixty-eight per cent of the community nitrogen content was lostas volatile NH₃ from the community during the reproductive period.Results suggested that the predominant net NH₃ efflux from thevegetation was determined by the low concentration of NH₃ inthe atmosphere ( 1.8 µg m^–2) and the compensationconcentration point. However, N losses were balanced by annualnitrogen input to the community from precipitation and biologicalfixation. Thus, a redistribution rather than a loss of nitrogenseems to be occurring in the ecosystem. Carbon dioxide fluxes, ammonia fluxes, Trachypogon savannas, energy balance, growth analysis     

Morphology and Morphogenesis of Two Species of the Genus Lembadion (Ciliophora, Oligohymenophora): Lembadion lucens and Lembadion bullinum

ABSTRACT. The morphology and morphogenesis of two species of the genus Lembadion, L. lucens and L. bullinum , are described. In both species, left and right ventral kineties converge behind the mouth forming a postoral suture. Buccal infraciliature is formed by one polykinety and two very close paroral kineties (inner and outer). During stomatogenesis, the new oral structures originate from the paroral kineties. The inner paroral kinety forms the new adoral polykinety and regenerates the outer paroral kinety of the proter, while the paroral kineties of the opisthe originate from the outer paroral kinety of the parental cell. Somatic proliferation starts before the stomatogenesis at the equatorial level of the cell, and extends towards the poles forming an equatorial band. Two large invariant zones, anterior and posterior, remain in the dividing cell. Moreover, the kinetodesmal fibers disappear in the proliferation band during the bipartition (fission) process.     

Density-dependent effects on productivity in the Griffon Vulture Gyps fulvus: the role of interference and habitat heterogeneity

Griffon Vultures Gyps fulvus in northern Spain were studied between 1969 and 1994. The number of breeding pairs increased from 221 in 1969–1975 to 1395 in 1994. The annual population growth rate decreased in the last 5 years, and this may reflect population regulation through density-dependent phenomena. Breeding success was monitored in 1994 and examined in relation to colony size, density of breeding pairs within a radius of 25 km (regional density), climate, human disturbance and food availability. We also recorded whether the year of first occupation of each nest site was before 1989 or after 1989 and whether or not the nest had a rocky shelter. The probability of successfully raising young declined as the regional density increased, which suggests that resource limitation would take place at foraging sites because the Griffon Vulture scavenges socially and no permanent feeding hierarchies are established. The other significant variable was the year of occupation of the nest; nests occupied after 1989 had a lower probability of raising a chick. The increase in the regional density of Griffon Vultures produced a decrease in the productivity at both optimal and suboptimal nest sites. This suggests that density-dependent regulation of breeding success operates through interference and that all the individuals in a colony are similarly affected. In birds of prey, prevalence of interference or habitat heterogeneity may be dependent on the social strategy of each species in space exploitation.     

Multiple Forms of the Constitutive Wheat Cinnamyl Alcohol Dehydrogenase

Three cinnamyl alcohol dehydrogenase (CAD) isoenzymes were separatedfrom etiolated wheat seedlings (Triticum aestivum L.) and examinedby native gel electrophoresis. Two of these enzymes (CAD-1 andCAD-2) were purified to apparent homogeneity. They exhibiteda marked difference in substrate affinity. On sodium dodecylsulphate-acrylamide gel the isolated isoenzymes showed onlyone protein band each with an M_r 45000 and 40000 daltons, respectively,whereas on native gel two bands were identified for each protein.Isoenzymes from a variety of diploid, tetraploid, and hexaploidwheats were compared. The results indicated that the CAD polymorphismcould be genetically determined. Key words: Cinnamyl alcohol dehydrogenase, lignin, Triticum aestivum L     

CONTRIBUTIONS TO THE KNOWLEDGE OF THE GENUS AEGIRES LOVEN, 1844 (OPISTHOBRANCHIA: DORIDOIDEA: AEGIRETIDAE) IN THE NORTH ATLANTIC, WITH DESCRIPTIONS OF TWO NEW SPECIES

New information on Aegires ortizi Templado, Luque & Ortea,1987 is given, and two new species of the genus Aegires aredescribed, one from the Caribbean and one from the MediterraneanSea. A key to the North Atlantic species of Aegires is given. (Received 10 February 1989; accepted 11 July 1989)     

Antigenic Makeup of Subcellular Fractions of Trypanosoma cruzi

Trypanosoma cruzi epimastigotes from cultures were separated into nuclear, mitochondrial, lysosomal, microsomal, and cell-sap fractions. Enzymic and ultrastructutal controls served to determine the cleanness of separation. The bulk of the DNA was in the nuclear (78%) and mitochondrial (12%) fractions. RNA was found in microsomal (74%) and cell-sap (14%) fractions. Marker enzyme distribution (succinic dehydrogenase, acid phosphatase, and glucose-6-phosphatase) was compared with their distribution in mammalian tissues. Subcellular localization of antigens by Ouchterlony tests revealed 2 specific precipitin lines in cell sap and 1 in the microsomal fraction. These antigens may prove diagnostically and immunoprotectively valuable.     

Primary Structure of Human Myoglobin

THE amino-acid sequence of myoglobin has been fully established in sperm whale¹, porpoise², harbour seal², horse³ and kangaroo⁴. It is known partially for the myoglobin of dolphin⁵, Macacus rhesus⁶, humpback whale⁷, Aplysia⁸ and man⁹.     

Enhancement of Intact Bean Leaf Senescence by NaCl Salinity

Red kidney bean (Phaseolus vulgaris L.) plants were grown in nutrient solution and in nutrient solution plus four bars of added NaCl. Chlorophyll and protein decay occurred much more rapidly in intact leaves from plants subjected to four bars of added NaCl in the growth medium than in intact leaves from plants without added NaCl. Ribonucleic acid (RNA) content in intact leaves of salt treated plants was higher than in intact leaves from plants grown in nutrient solution alone. However, the tendency for RNA content variation in leaves during the experimental period was the same for both control and salt treated plants. The results support the idea that salinity enhances senescence and suggests that hormone imbalance plays an important role in this process.