Occurrence of Myrica-nodulating Frankia in Hawaiian volcanic soils

The ability of Hawaiian volcanic soils to nodulate actinorhizal Myrica cerifera, Casuarina equisetifolia, and Alnus glutinosa was determined using a host-plant bioassay. Myrica-nodulating Frankia occurred in five volcanic deposits with depositional ages ranging from 20 to 162 years before present. The oldest deposit had a mean estimated nodulation capacity from 450 to 1200 times greater than those of the younger deposits. Only the oldest deposit had high moisture content, high organic matter content, and increased vegetative cover, including an abundance of actinorhizal M. faya. Casuarina- and Alnus-nodulating Frankia were not detected in any of these volcanic deposits.     

Pollarding and a possible explanation of the neolithic elmfall

Sections of two pollarded parkelms (Ulmus glabra) from Damsgaard, Bergen, west Norway have been studied. Changes in annual ring-width are attributed partly to management, namely pollarding, and partly to pathogenic attacks, probably by Ceratocystis ulmi. The oldest attack on the trees dates back to 1826: so far the oldest known record of Dutch elm disease in Norway. Pollarding may be an important factor in attacks by the pathogen within parkelms. A possible relationship between pollarding, the pathogen and the Neolithic elmfall is suggested.     

Social and ecological contexts of trophallaxis in facultatively social sweat bees, Megalopta genalis and M. ecuadoria (Hymenoptera, Halictidae)

Exchange of liquid food among adults (trophallaxis) is documented for the first time in New World sweat bees (Halictinae). Megalopta genalis and M. ecuadoria are facultatively social, and in social groups foragers regularly give food to the oldest resident female bee, which dominates social interactions. In turn, the oldest resident sometimes re-distributes this food, and shares it with younger foragers. Food is sometimes offered freely, but often the dominant bee exhibits escalating aggressive behavior until she is fed, whereupon she immediately ceases to be aggressive. The occurrence of trophallaxis in a species with mass-provisioned larvae provides an opportunity to examine the ritualization of social behavior. Trophallaxis also increases survivorship of males and females by almost 50% under experimental conditions, suggesting the behavior is also important in ecological contexts. Received 25 July 2005; revised 22 November 2005; accepted 23 December 2005.     

Geographical distribution of Polycelis (Seidlia) auriculata in Japan

Polycelis (Seidlia) auriculata is endemic to mountain districts of Japan, from the central part of Honshû to the area of the Daisetsu Mts of Hokkaidô. In northern Japan, it sometimes occurs in cold-water biotopes of lowland areas. The progenitor of P. auriculata appears to have been the oldest immigrant into northern Japan among the Japanese Polycelis species, entering through a northern route as a preglacial faunal element. P. auriculata now shows a discontinious distribution in northern Japan. By virtue of its geographical and vertical distribution, ecological niche, variation in anatomy of the copulatory apparatus, and cytodemes, this species appears to be in the process of transformation.     

Systematics and phylogeny of theCompositae (Asteraceae)

Compositae (Asteraceae) are remarkably homogenous in basic type of inflorescence, flower and fruit. TheCichorioideae are more closely related to the other groups than usually realized. The classical concept of theAsteroideae tribes has been confirmed in general, but recent investigations (using palynology, carpology, phytochemistry etc.) suggest numerous corrections, and some genera (e.g.Liabum, Echinops, Tarchonanthus, Arnica) do not fit into the scheme. The tribes ofAsteroideae may be divided into two groups characterized by several common characters and common tendencies. The oldest reliable fossils are known from the borderline Oligocene/Miocene. Looking for the nearest relatives,Campanulales (incl.Calyceraceae) and—because of interesting phytochemical agreements—Araliales have to be discussed.This paper was read at the XIIth International Botanical Congress, Leningrad, July 1975.     

Taxonomic status of the hominine cranium KNM-ER 1813 (primates: Homininae) from the Plio/Pleistocene of Koobi Fora

The hominine cranium KNM-ER 1813, from the late Plio/Pleistocene of Koobi Fora, has been regarded recently by some authors as a female ofHomo habilis Leakey, Tobias, andNapier, 1964 and by others as an enigma. Reassessment of its cranial morphology, dental metrics, proportions, and a new detailed determination of its sex indicates that it does not conform with the diagnosis forH. habilis, and is probably a male. It is sympatric withH. habilis yet shows more primitive features and rather a closer affinity to the smaller, more primitive chronospeciesH. antiquus Ferguson, 1984, and is thus the first, nearly complete skull of our oldest known human ancestor.     

Magnesium deficiency in sugar beets alters sugar partitioning and phloem loading in young mature leaves

Magnesium deficiency has been reported to affect plant growth and biomass partitioning between root and shoot. The present work aims to identify how Mg deficiency alters carbon partitioning in sugar beet (Beta vulgaris L.) plants. Fresh biomass, Mg and sugar contents were followed in diverse organs over 20 days under Mg-sufficient and Mg-deficient conditions. At the end of the treatment, the aerial biomass, but not the root biomass, of Mg-deficient plants was lower compared to control plants. A clear inverse relationship between Mg and sugar contents in leaves was found. Mg deficiency promoted a marked increase in sucrose and starch accumulation in the uppermost expanded leaves, which also had the lowest content of Mg among all the leaves of the rosette. The oldest leaves maintained a higher Mg content. [¹⁴C]Sucrose labelling showed that sucrose export from the uppermost expanded leaves was inhibited. In contrast, sucrose export from the oldest leaves, which are close to, and export mainly to, the roots, was not restricted. In response to Mg deficiency, the BvSUT1 gene encoding a companion cell sucrose/H⁺ symporter was induced in the uppermost expanded leaves, but without further enhancement of sucrose loading into the phloem. The observed increase in BvSUT1 gene expression supports the idea that sucrose loading into the phloem is defective, resulting in its accumulation in the leaf.     

Size-selective predation by fourhorn sculpin,Myoxocephalus quadricornis (L.) (Pisces) on Mesidotea entomon (L.) (Crustacea,Isopoda)

During three different seasons Mesidotea entomon specimens from fourhorn sculpin stomachs were analyzed, and compared with the M. entomon population in the field. The field samplings were carried out in the northern Bothnian Sea. Feeding experiments revealed fourhorn sculpins to be highly selective when feeding on M. entomon.The fourhorn sculpin most preferably selected large M. entomon in the field as well as in the laboratory experiments. The preference for large M. entomon remained after correction for availability of differently sized M. entomon. In summer the actual sizes of M. entomon eaten by fourhorn sculpin were smaller than in autumn and winter. During all three seasons the oldest M. entomon were the ones most preferred. Ultimate effects of predation by fourhorn sculpin on the life-history of M. entomon are discussed.     

Anatomical changes and evolutionary trends in the foliar epidermis of extant and fossil Euro-Mediterranean oaks (Fagaceae)

The differentiation of foliar epidermis structures, cuticles, stomata, and indumentum of most of the extant Euro-Mediterranean taxa ofQuercus have been studied by light and scanning electron microscopy, and compared with other genera and fossil material. Results allow the recognition of the subgg.Sclerophyllodrys, Cerris andQuercus, and of various sections and even individual species. The cyclocytic stomata type, regarded as plesiomorphic, is found in the geologically oldest representatives of the familiy (Dryophyllum, resp.Eotrigonobalanus) and in the relatively old, evergreen to semi-evergreen species ofQuercus subgg.Sclerophyllodrys andCerris. These taxa also have relatively thick and smooth cuticles. Anomocytic stomata, thinner cuticles and the presence of crystalline wax flakes are regarded as apomorphic features and characterize the deciduous taxa of subg.Quercus. These changes are interpreted as ecological adaptations to the changing climates from the Tertiary to the present. An analysis of the various character combinations found in macrofossils and the often poor species separation inQuercus suggest that hybridization has played a major role in the evolution of the Euro-Mediterranean oaks.     

Transposon display supports transpositional activity of <Emphasis Type="Italic">P</Emphasis> elements in species of the <Emphasis Type="Italic">saltans</Emphasis> group of <Emphasis Type="Italic">Drosophila</Emphasis>

Mobilization of two P element subfamilies (canonical and O-type) from Drosophila sturtevanti and D. saltans was evaluated for copy number and transposition activity using the transposon display (TD) technique. Pairwise distances between strains regarding the insertion polymorphism profile were estimated. Amplification of the P element based on copy number estimates was highly variable among the strains (D. sturtevanti, canonical 20.11, O-type 9.00; D. saltans, canonical 16.4, O-type 12.60 insertions, on average). The larger values obtained by TD compared to our previous data by Southern blotting support the higher sensitivity of TD over Southern analysis for estimating transposable element copy numbers. The higher numbers of the canonical P element and the greater divergence in its distribution within the genome of D. sturtevanti (24.8%) compared to the O-type (16.7%), as well as the greater divergence in the distribution of the canonical P element, between the D. sturtevanti (24.8%) and the D. saltans (18.3%) strains, suggest that the canonical element occupies more sites within the D. sturtevanti genome, most probably due to recent transposition activity. These data corroborate the hypothesis that the O-type is the oldest subfamily of P elements in the saltans group and suggest that the canonical P element is or has been transpositionally active until more recently in D. sturtevanti.     

Species-specific albumin in fossil bones from Orce, Granada, Spain

A skull fragment (VM-0) from Orce, Granada, Spain, dated palaeomagnetically at about 1.6 Myr, is thought by some palaeontologist to be hominid, while others maintain it is equid. If hominid, it would be by far the oldest evidence ofHomo in Europe. Immunological studies on residual albumin in this fossil were carried out independently, and with different immunological methods, at the University of California, San Francisco (radioimmunoassay), and at the University of Granada, Spain (enzyme immunoassay). Other fossils attributed to hominids also studied wereVM1960 from Venta Micena, andCV-1 from Cueva Victoria, Murcia, Spain. Undisputed equid and bovid fossils from the same deposits and dated to a similar period as the Orce skull were also analyzed. Our results showed that species-specific albumin can be detected in 1.6 Myr-old hominid, equid and bovid fossils. The albumin from the Orce skull fragment and fromVM-1960 was immunologically closer to human albumin. These findings support the contention that theVM-0 andVM-1960 are hominid and that members of the genusHomo occupied southern Spain 1.6 Myr ago.     

Zebra mussels (Dreissena polymorpha): a new perspective for water quality management

In the evaluation of the role of lake restoration programmesin situ measurements of the filtration rate of the freshwater musselDreissena polymorpha have been performed in Lake Wolderwijd, The Netherlands. The filtration rate mainly depends on the suspended matter content of the water, and shows an inverse exponential relationship with this factor. The filtration activity is temperature indifferent between approx. 5 and 20 °C. At low temperatures the filtration rate drops abruptly, at high temperatures gradual inhibition occurs. The filtration rate shows a sigmoidal relation with the length of the mussel. The largestD. polymorpha have a diminished filtration rate compared to animals of smaller size. This might be a degenerative feature of the oldest mussels. In Lake Wolderwijd a population density of 675 per m² is required to compensate phytoplankton growth by grazing. Manipulation of the size of the population can be executed by adding suitable substrates for the mussel.     

Molecular cloning, characterization and expression of atpA and atpB genes from Ginkgo biloba

The chloroplast ATP synthase (ATPase) utilizes the energy of a transmembrane electrochemical proton gradient to drive the synthesis of ATP from ADP and phosphate. The chloroplast ATPase α and β subunits are the essential components of multisubunit protein complex. In this paper, the full-length cDNA and genomic DNA of ATPase α (designated as GbatpA) and β (designated as GbatpB) subunit genes were isolated from Ginkgo biloba. The GbatpA and GbatpB genes were both intronless. The coding regions of GbatpA and GbatpB were 1530 bp and 1497 bp long, respectively, and their deduced amino acid sequences showed high degrees of identity to those of other plant ATPase α and β proteins, respectively. The expression analysis by RT-PCR revealed that GbatpA and GbatpB both expressed in tissue-specific manners in G. biloba and might involve in leaf development. The recombinant GbATPB protein was successfully expressed in E. coli strain using pET28a vector with ATPase activity as three times high as the control, and the results showed that the molecular weight of the recombinant protein was about 54 kDa, a size that was in agreement with that predicted by bioinformatics analysis. This study provides useful information for further studying on overall structure, function and regulation of the chloroplast ATPase in G. biloba, the so-called “living fossil” plant as one of the oldest gymnosperm species. These authors contributed equally to this work     

Trachypithecus auratus sangiranensis,A New Fossil Monkey from Sangiran,Central Java,Indonesia

We describe a new extinct subspecies of the Javan lutung—Trachypithecus auratus sangiranensis—based on an isolated, tooth-bearing upper jaw. The specimen was in volcanic breccia situated between the Lower Pucangan and the Upper Kalibeng Formations 500 m south of the village of Sangiran, near Surakarta, central Java, Indonesia. The new fossil monkey bears morphological similarities to the two living species of leaf monkey from Java, Presbytis comata comata and Trachypithecus auratus auratus, and to the Middle Pleistocene form, Trachypithecus cristatus [=auratus] robustus, from Tegoean, central Java. It is significantly larger than any of these forms, and differs from them in details of dental anatomy. Because the greatest number of similarities are between the new fossil and Trachypithecus auratus subspecies, we designated the specimen as T. a. sangiranensis. The geochronological age of the breccia from which the fossil came, is 1.9± 0.05 Ma (million years), making T. a. sangiranensis one of the oldest fossil monkeys from eastern Asia.     

Structure and dynamics of an ancient montane forest in coastal British Columbia

Old-growth forests are common in the snowy, montane environments of coastal western North America. To examine dynamics of a stand containing four canopy tree species (Abies amabilis, Chamaecyparis nootkatensis, Tsuga mertensiana and T. heterophylla), we used four stem-mapped, 50 m ×50 m plots. From measurements of annual rings, we obtained ages from basal discs of 1,336 live trees, developed master chronologies for each species, reconstructed early growth rates, and delineated periods of release. The stand was ancient; individuals of all four species exceeded 900 years in age, and the oldest tree exceeded 1,400 years. The four plots differed in the timing of events, and we found no evidence of major, stand-level disturbance. Instead the stand was structured by small-scale patch dynamics, resulting from events that affected one to several trees and initiated episodes of release and relatively rapid early growth. The species differed in age structure and dynamics. A. amabilis and T. heterophylla had a classical reverse-J age structure indicative of stable populations, whereas C. nootkatensis and T. mertensiana appeared to rely on local episodes of increased recruitment, which were often separated by centuries, and were probably related to multiple-tree gaps that occurred infrequently. However, such gaps could be considered normal in the long-term history of the stand, and thus these species with their long life spans can persist. Most individuals of all four species grew extremely slowly, with trees typically spending centuries in the understory before reaching the canopy, where they were able to persist for additional centuries. Thus, the key features of this forest are the very slow dynamics dominated by small-scale events, and the slow growth of stress-tolerant trees.     

Determinants for the conservation of a vulnerable fire-dependent species at its marginal range

We investigated the role of fire and other potential biotic and abiotic determinants for the occurrence of an obligate seeder and active pyrophyte, Cistus salviifolius, a vulnerable species in the Swiss Red List. Populations of this species are threatened by the change of fire regime that has occurred during the last ten years. Fires and burnt areas are today less frequent and it is not clear whether other factors can compensate for such fire-free periods should this trend continue. We used a stratified random design to collect data on the cover of three growth stages, i.e., juvenile, chamaephytic and nanophanerophytic (oldest), of C. salviifolius, on plant communities, and on environmental factors. A tree-based discriminant analysis showed that the time elapsed since last fire was the best predictor of Cistus occurrence, but plants could survive on rocky and sunny sites if no fire had occurred for more than 32 years. Contrary to our expectations, the number of fires and time elapsed since the last event was correlated with the oldest stages only, and not with that of seedlings or juveniles. Rank correlations showed that bare soil was a good predictor of young stages, whereas rocky outcrops and shallow soils were important for the chamaephytic stage. Our results confirm the role of disturbances and competition-free habitats as determinants of the survival of this vulnerable pyrophyte during long periods without fires and the existence of ontogenetic niche segregation of this species. In order to maintain viable C. salviifolius populations in the Alps, managers should undertake conservation actions according to the requirements of the different growth stages of this species.     

Changes in Activities of Antioxidant Enzymes in Sunflower Leaves of Different Ages

Role of superoxide dismutase isozymes and other antioxidant enzymes was studied in relation to leaf age in sunflower (Helianthus annuus L. cv. ACC 1508) at pre-flowering and grain filling stages. Relative water content (RWC) did not change much in leaves of different age and at the two stages. Protein content declined continuously from the youngest to the oldest leaf, while chlorophyll (Chl) and carotenoids (Car) contents increased down to 7^th/9^th leaf and declined in subsequent older leaves. Protein, Chl and Car contents were higher at pre-flowering than at seed filling stage. Superoxide dismutase (SOD), its isozymes, and ascorbate peroxidase (APO) and catalase (CAT) activities were highest in the 9^th leaf and declined in subsequent older leaves. SOD and APO activities were higher at seed filling, except in oldest senescent (13^th, 15^th) leaves. Among SOD isozymes, Cu/Zn-SOD and Mn-SOD activities accounted for most of the total SOD, and only marginal activity was observed for Fe-SOD. Peroxidase activity increased from youngest to the oldest leaf at pre-flowering stage and down to 13^th leaf at seed filling stage. This revised version was published online in July 2006 with corrections to the Cover Date.     

Successful amplification of rice chloroplast microsatellites from century-old grass samples from the park grass experiment

We report the successful amplification of microsatellite markers for the chloroplast genome from century-old samples of 2 grasses growing in the Park Grass Experiment (PGE):Anthoxanthum ordoratum andFestuca rubra. This opens the possibility of establishing a long-term genetic time series for the PGE, which began in 1856 and is believed to be the oldest ecological experiment in existence. Although the plant samples used were not originally prepared or stored with molecular analysis in mind, the hexadecyltrimethylammonium bromide (CTAB) method of DNA extraction was successfully used. Obtained DNA was degraded but could be amplified by means of PCR. It produced bands around the expected size for chloroplast microsatellite primers derived from rice. When sequenced, bands showed good homology with sequences from rice chloroplast genomes listed in GenBank (accession No X15901).     

The ultrastructure and calcification of the scales of Tilapia mossambica (Peters)

Summary The scales of Tilapia are surrounded by an envelope of scleroblasts responsible for the production of layers of collagen that constitute the bulk of the scale. The scleroblasts adjoining the lateral face of the oldest scale region gradually atrophy. New collagen layers are deposited against the inner face of the scale, the adjoining scleroblasts showing evidence of high metabolic activity. Calcification occurs by inotropic deposition of crystals alongside the fibres. There is no sharp demarcation between calcified and non-calcified scale regions, a calcification front gradually moving towards newly formed collagen layers. It is felt that fish scales should be considered as calcified derivatives of dermal collagen layers.     

Paleobotanical studies inFagaceae of the European Tertiary

A systematic reassessment of megafossil records ofFagaceae in Central Europe has been undertaken on the basis of leaf cuticular characters. The oldest representatives date back to the Eocene:Quercus subhercynica spec. nova,Dryophyllum furcinerve (Rossm.)Schmalh.,Trigonobalanopsis rhamnoides (Rossm.) gen. & comb. nov. In the Oligocene other members of extant genera appear:Quercus rhenana (Weyl. & Kilpp.)Knobloch & Kvaek,Fagus attenuata Goepp.,Lithocarpus saxonicus spec. nova. In the Neogene these ancient taxa (except inFagus lineage), are gradually replaced by deciduous species ofQuercus andCastanea. Trigonobalanus andCastanopsis are recorded by fruits (or wood) only.