bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial Autocorrelation of Allozyme Variants among Korean Populations of Calystegia soldanella and C. japonica (Convolvulaceae)
Authors: CHUNG MYONG GI , KANG SOON SUK
Published: February 2005

Abstract We investigated the spatial distribution of genotypes among Korean populations of Calystegia soldanella and C, japonica. Calystegia soldanella grows only on sand and beach dunes in East Asia and reproduces both sexually and asexually, whereas C. japonica inhabits fields and roadsides in this region, and the species reproduces exclusively by underground rhizomes. Spatial autocorrelation analysis was used to investigate the spatial distribution of genotypes of 15 and 12 alleles among 13 and eight Korean populations of C. soldanella and C. japonica, respectively. For C. soldanella, within a distance of 0–123 km, all eight significant Moran's I values were positive, indicating genetic similarity among populations within the circumference. On the other hand, in C. japonica, three significant negative autocorrelation coefficients within a 0–121 km distance were detected. The observed patterns of spatial genetic structure in both species may result from differences between them in life history and ecological traits.
Reproductive Biology of Oxalis corniculata (Oxalidaceae): Style Length Polymorphisms and Breeding Systems of Japanese Populations
Authors: SHIBAIKE HIROYUKI , ISHIGURI YOSHIO , KAWANO SHOICHI
Published: February 2005

Abstract Style length polymorphisms and breeding systems of Oxalis corniculata populations in Japan were investigated. In Japan this species is composed of two floral morphs, a homostyled morph in which the level of the stigma and the anther of longer stamens are more or less the same, and a long‐styled morph in which the stigmas conspicuously protrude from the level of anthers of the longer stamens. Homostyled plants are common in artificially disturbed urban and ruderal habitats, whereas long‐styled plants occur mainly in less disturbed habitats of maritime Pinus thunbergii forests. Each of five populations examined in this study was exclusively composed of one or the other of the two floral morphs, with no mixed populations observed. Measurements of floral traits and reproductive parameters indicated that plants of homostyled populations exhibited characteristics of a typical autogamous breeding system, whereas those of long‐styled populations exhibited characteristics of predominant outcrossing. Crossing experiments revealed that the length of the stigmas and anthers of longer stamens, which characterizes the two floral morphs, is quantitatively inherited. The results obtained suggest that disassortative pollination among different floral morphs, which is commonly observed in some other heterostylous species, does not occur in O. corniculata populations in Japan. The origin of homostyled and long‐styled morphs in O. corniculata is also discussed.
Growth Responses of the Cuttings of Two Willow Species to Elevated CO2 and Temperature1)
Authors: KOIKE TAKAYOSHI , KOHDA HIDEHO , MORI SHIGETA , TAKAHASHI KUNIHIDE , INOUE MARIO T. , LEI THOMAS T.
Published: February 2005

Abstract Growth of the cuttings of two willows (Salix sachalinensis Fr. Schmidt and S. miyabeana Seeman) was examined at CO2 levels of 36 Pa and 70 Pa and at two temperature regimes to assess possible changes in the competitive abilities between the two species under elevated CO2 and temperature. Both willows are typical light demanding species. At 70 Pa CO2, the formation of sylleptic shoots of was accelerated to a greater extent in S. sachalinensis than in S. miyabeana. In both species, leaf area, specific leaf area, and chlorophyll and nitrogen concentrations decreased under elevated CO2. A positive correlation between foliar nitrogen concentration and net photosynthetic rate measured at growth CO2 level was observed. In all treatments, nitrogen use efficiency for the photosynthetic capacity was higher in S. sachalinensis than in S. miyabeana. After 78 days of cultivation, dry mass of the whole plant was 1.5 times greater for S. miyabeana than for S. sachalinensis. Under fertile conditions, S. miyabeana may be more competitive than S. sachalinensis in an early stage of regeneration as a result of its rapid height growth.
Seed Ecology of Lobelia boninensis Koidz. (Campanulaceae), an Endemic Species in the Bonin Islands (Japan)
Authors: MARIKOCO SHIGERU , KACHI NAOKI
Published: February 2005

Abstract We examined seed germination of Lobelia boninensis Koidz. (Campanulaceae) in incubators and its seed production in a greenhouse. This monocarpic perennial is an endemic and endangered species in the Miscanthus boninensis vegetation on coastal cliffs in the Bonin Islands. Seeds germinated over a range of from 10° to 30°C; at these temperatures germination began only after eight days of incubation. A cool, moist stratification treatment did not promote germination. Based on these temperature responses, it is expected that in their native habitat Lobelia seeds germinate between October and November, when precipitation is frequent. Lobelia which remain capable of germinating for a few years after storage in the lab, are positively photoblastic, and this may allow the seeds to detect gaps or safe sites in vegetation. These results suggest that Lobelia seeds may form a seed bank beneath a closed canopy, due to enforced dormancy. Lobelia seeds germinated under saline conditions up to 300 mM NaCI. In the greenhouse, some individuals began to reproduce 2.5 years after germination. Plants are self‐compatible, and they produced an average of >4.5 × 105 small seeds (ca. 0.12 mg). Lobelia has a strategy of seed germination suited to colonize the M. boninensis vegetation, where the maritime impact is reduced. This endangered species can easily be propagated ex situ.
Relationship between Flower Number and Reproductive Success of a Spring Ephemeral Herb, Anemone flaccida (Ranunculaceae)
Authors: NISHIKAWA YOKO , KUDO GAKU
Published: February 2005

Abstract Flowering phenology and reproductive traits of Anemone flaccida were compared between ramets having one, two, and three flowers. We evaluated the flowering pattern and the reproductive function of each flower within a ramet and discussed the ecological significance of flower number. Early‐blooming flowers had larger numbers of pistils and stamens, higher seed‐set, and heavier seeds than the later‐blooming flowers within a ramet under natural conditions. These differences remained after flowers were hand‐pollinated. When one flower was removed from a ramet with two flowers, seed‐set and seed weight of the remaining flower did not increase. Because flowering occurs sequentially within a ramet, anthesis per ramet was extended with flower number. Production of the second and the third flowers was considered for plants to reduce entire failure in setting seeds under the condition of unpredictable pollinator activity. However, it was thought that having more than three flowers makes it hard to complete the life‐cycle during the growing season (mid‐April to early June).
Optimal Resource Allocation to Seeds and Vegetative Propagules in the Understory Herb Syneilesis palmata (Compositae)
Authors: NISHITANI SATOMI , TAKADA TAKENORI , KACHI NAOKI
Published: February 2005

Abstract The aim of the present study was to evaluate the fitness consequences of resource allocation balance between seeds and vegetative propagules in an understory herb, Syneilesis palmata. Based on field censuses, transition matrices were constructed to compare the fitness of hypothetical S. palmata populations with different allocation balances (from seeds alone to vegetative propagules alone). We obtained the dominant eigenvalue (λ) of each matrix, which gives the finite rate of population increase, i.e. a fitness measure for a population with overlapping generations. The value of λ was highest when the relative allocation to seeds (P) was zero and decreased as P increased, indicating that the optimal strategy was to reproduce only vegetatively. Seed reproduction was favored only under quite unrealistic situations such as production of 500–1000 times more seeds per unit investment than those observed in the real plants, or seedling growth under full sun light. The majority of fertile plants, however, produced seeds in addition to vegetative propagules in the natural habitats. The results of our simulations provide quantitative, though indirect, evidence for important roles of seeds in dispersal and/or sexual reproduction.
Pollination Ecology ofPedicularis parryissp.purpurea(Parry) Carr (Scrophulariaceae)
Authors: MACIOR LAZARUS WALTER
Published: February 2005

AbstractThe pollination ecology ofPedicularis parryi purpureagrowing in a drier, upland, sagebrush meadow was studied in association withP. bracteosa paysonianaimmediately adjacent in a rich, moist willow thicket in the Teton Mountain Region of Wyoming. By insect exclosure,P. parryi purpureawas found to beBombuspollinator‐dependent. While both plants bloomed synchronously, had nectariferous corollas with similar nectars analyzed by refractometry and thin‐layer chromatography, and shared the same eightBombuspollinator species,P. parryi purpureawas pollinated primarily by short‐tongued, sternotribic pollen‐foragers andP. bracteosaby long‐tongued, nototribic, nectar gatherers. Microscopic examination of 276 corbicular pollen loads fromPedicularispollinators to determine pollen‐foraging constancy yielded 49% queens and 82% workers constant onP. parryi purpurea, 83% queens and 78% workers onP. bracteosa paysoniana.No putative hybrids between these species were identified; hybridization inPedicularisis considered rare or absent.
Evolutionary Biology of Trillium and Related Genera (Trilliaceae) II. Cladistic Analyses on Gross Morphological Characters, and Phylogeny and Evolution of the Genus Trillium
Authors: KAWANO SHOICHI , KATO HIDETOSHI
Published: February 2005

Abstract Cladistic analyses were conducted based upon 22 gross morphological and one floral odor characters for 42 Trillium species, one Kinugasa, one Daiswa, and two Paris species of the Trilliaceae, using Daiswa and Paris as outgroups. The cladistics provided an informative result with regard to the affinity and phylogeny of the taxa referred to the genus Trillium and related genera in the Trilliaceae, suggesting that Trillium is composed of four major infrageneric groups: (1) the pedicellate‐flowered group represented by the Erectum group including 13 species, (2) the Undulatum group, a loosely clustered paraphyletic group including five species, (3) the Govanianum group consisting of only two species, and (4) the Sessile group including 22 species. The monophyly of the Sessile group is very evident. The results are concordant with the earlier results of the RFLP analysis of cpDNA conducted by us. It is noteworthy, however, that the pedicellate‐flowered group of Trillium is not simply monophyletic, as was assumed previously, but instead consists of at least three to four distinct groups as noted above. The implications and limitations of using distantly related genera, such as Daiswa or Paris as outgroups, in the cladistic analysis were also argued.
Evolution in the Genus Zea: Lessons from Studies of Nucleotide Polymorphism
Authors: GAUT BRANDON S.
Published: February 2005

Abstract The genus Zea consists of the cultivar maize and six wild taxa. All taxa in the genus hybridize with one another, and the genus appears to be of relatively recent origin. The genus Zea has long been of interest to evolutionary and molecular geneticists, and a plethora of studies have established that maize and the teosintes are genetically diverse. This high diversity, coupled with relatively recent divergence among taxa, makes Zea an excellent model system for studying the distribution of nucleotide diversity both among recently diverged taxa and among a crop and its wild relatives. Nucleotide diversity has been studied in a number of maize loci. These studies have documented tremendous nucleotide variation in maize, and they suggest that allelic lineages in the maize gene pool can be quite long‐lived. For example, it has been estimated that allelic lineages have existed for several million years at both the Adh 1 and the Adh2 locus, suggesting that the common ancestor to Zea taxa was highly polymorphic. These studies have also found ample evidence of recombination in maize loci, suggesting that recombination plays an important role in generating haplotype diversity. A recent study of the regulatory locus c1, a regulatory gene in the anthocyanin biosynthesis pathway, belies this general picture. Alleles from the c1 locus have been sampled from maize and teosintes. The sampled alleles fall into two discrete groups, corresponding to two distinct functional classes. Both classes are found in teosinte, but only one of these classes is found in maize. The c1 locus is less diverse than any other maize locus yet examined. It is hypothesized that low nucleotide diversity at the c1 locus is a consequence of selection, probably artificial by the early domesticators of maize.
Characterizing Molecular Quantitative Variability for Inbreeding Depression
Authors: RITLAND KERMIT , FU YONG‐BI , LIN JING‐ZHONG
Published: February 2005

Abstract Molecular quantitative genetics seeks to map and characterize the effects of individual genes underlying traits (quantitative trait loci, or QTLs). Classically, it uses genetic differences between distinct strains or taxa and saturated marker maps to infer the location and effects of specific genes. Little attention has been devoted to characterizing QTL variability within populations, as higher heterozygosity and smaller allele effects require much larger experimental effort to detect specific QTLs. An alternative approach for within‐population studies is to utilize multiple crosses, each assayed for relatively few genetic markers. The genome regions surveyed for QTLs are regarded as random samples, with the objective of characterizing variability of QTLs. This approach is particularly appropriate for genetically heterogeneous traits such as inbreeding depression and life history (e.g., fitness) traits. In this paper, we explore this approach for QTLs affecting inbreeding depression, based upon a method using selfed progeny arrays, and illustrated with an experiment involving the common monkeyflower, Mimulus guttatus.
Molecular Variation in Isolated Plant Populations
Authors: SCHAAL BARBARA A. , LEVERICH WESLEY J.
Published: February 2005

Abstract Isolated plant populations face a series of demographic and genetic challenges. They potentially may suffer from a loss of allelic and genotypic diversity or from inbreeding depression. The demographic stability associated with migration between components of a metapopulation is lost as fragmentation increasingly isolates populations. Such isolated populations are then increasingly subject to demographic stocasticity and to more frequent population bottlenecks. Some plant species clearly endure this challenge better than others. In studies of native plant species whose populations have long endured isolation, population numbers very often appear stable and populations often contain ample genetic variation. Of course, such observations are biased, since those species which did not accommodate isolation are presumed extinct and thus not studied.

When one considers species which have recently undergone habitat fragmentation and population isolation, the ability to accommodate such change is clearly not present in many species. Such populations often show a dramatic decline in numbers as well as erosion of genetic variability. In these populations the role of somatic processes in the generation of genetic variation may assume an increased importance. Since only a few isolated studies have documented such somatic genomic changes in plants, the importance of such changes is subject to speculation.
The Amount of Genetic Variation at the DNA Level Maintained in a Finite Population
Authors: TAJIMA FUMIO
Published: February 2005

Abstract The amount of DNA polymorphism can be estimated either from the average number of pairwise nucleotide differences per site (π) or from the proportion of segregating (polymorphic) site (s) among a sample of DNA sequences. Under a number of assumptions, including panmictic population and neutrality, it is known that the expectations of π and s are given by E(π) =θ and E(s) = a1(n)θ, where θ= 4Nv, a1(n) = 1 + 1/2 +…+ 1/(n‐1), N is the effective population size, v is the mutation rate per site per generation, and n is the sample size. Therefore, θ can be estimated by π or s/a1(n). These assumptions, however, are not always correct. In this paper, using a simple non‐random sampling model, I have examined the effect of non‐random sampling on the estimates of the amount of DNA polymorphism. The results indicate that the effect of non‐random sampling on the proportion of segregating site is substantially large whereas the effect of non‐random sampling on the average number of nucleotide differences per site is negligibly small unless non‐randomness is extremely large. Using a finite site model with and without rate variation, I have also examined the effect of rate variation among sites on the estimates of the amount of DNA polymorphism. The results indicate that if the neutral mutation rate varies among sites substantially, the estimates of θ based on the infinite site model are substantially underestimated. New methods for estimating θ are also presented.
Developmental Reaction Norms: the Interactions among Allometry, Ontogeny and Plasticity
Authors: PIGLIUCCI MASSOMO , SCHLICHTING CARL D. , JONES CYNTHIA S. , SCHWENK KURT
Published: February 2005

Abstract How micro‐ and macroevolutionary evolutionary processes produce phenotypic change is without question one of the most intriguing and perplexing issues facing evolutionary biologists. We believe that roadblocks to progress lie A) in the underestimation of the role of the environment, and in particular, that of the interaction of genotypes with environmental factors, and B) in the continuing lack of incorporation of development into the evolutionary synthesis. We propose the integration of genetic, environmental and developmental perspectives on the evolution of the phenotype in the form of the concept of the developmental reaction norm (DRN) The DRN represents the set of multivariate ontogenies that can be produced by a single genotype when it is exposed to environmental variation. It encompasses: 1) the processes that alter the phenotype throughout the ontogenetic trajectory, 2) the recognition that different aspects of the phenotype are (and must be) correlated and 3) the ability of a genotype to produce phenotypes in different environments. This perspective necessitates the explicit study of character expression during development, the evaluation of associations between pairs or groups of characters (e.g., multivariate allometries), and the exploration of reaction norms and phenotypic plasticity. We explicitly extend the concept of the DRN to encompass adjustments made in response to changes in the internal environment as well. Thus, ‘typical’ developmental sequences (e.g., cell fate determination) and plastic responses are simply manifestations of different scales of ‘environmental’ effects along a continuum. We present: (1) a brief conceptual review of three fundamental aspects of the generation and evolution of phenotypes: the changes in the trajectories describing growth and differentiation (ontogeny), the multivariate relationships among characters (allometry), and the effect of the environment (plasticity); (2) a discussion of how these components are merged in the concept of the developmental reaction norm; and (3) a reaction norm perspective of major determinants of phenotypes: epigenesis, selection and constraint.
A Case Study in Experimental Evolution: Reproductive Effort and Induced Responses in Drosophila melanogaster
Authors: STEARNS STEPHEN C. , KAISER MARCEL , BLARER ALBERT
Published: February 2005

Abstract To understand the causes of tradeoffs, particularly those involved in ageing, to test the reproductive effort model of life history evolution, and to measure the rate of evolution of induced life history responses, we have been performing an artificial selection experiment on Drosophila melanogaster since November 1993. It consists of four treatments, each with three replicates.

The first treatment consists of constant high adult mortality; the second treatment of constant low adult mortality. In all four treatments, propyl acetate is present in the medium for 4 weeks, then absent for 4 weeks. In the third treatment, propyl acetate in the larval medium is associated with high adult mortality. In the fourth treatment, propyl acetate is associated with low adult mortality. To ensure that the effects of treatments are due to differences in mortality and not in density, adult and larval density are kept the same in all treatments.

In the first two treatments, the evolution of reproductive effort and age and size at maturity has been rapid and has confirmed the predictions of the reproductive effort model. The relationships between age and size at eclosion and between size at eclosion and fecundity have also evolved. Because the only difference between the first two treatments was the level of adult mortality, this establishes differences in mortality rates as a sufficient cause for the evolution of age and size at eclosion and for the age‐distribution of fecundity rates.

In the second two treatments, the evolution of induced responses has been slow, and responses are not yet consistent. The reasons for the slower evolution of induced responses suggest two new theoretical questions.
Allometric Limits to the Induced Accumulation of Nicotine in Native Tobacco
Authors: BALDWIN IAN T.
Published: February 2005

Abstract The induced defenses of plants are, by definition, examples of adaptive phenotypic plasticity; however, they have rarely been considered as such due largely to the difficulty of defining the character states of these dynamic chemical responses. Nicotine functions as an inducible defense in Nicotiana sylvestris and is one of the few induced defenses which is understood on a whole‐plant basis. Nicotine biosynthesis is restricted to the roots and increases after wounding or herbivore attack to the shoot. Newly synthesized nicotine is transported throughout the plant; induced plants are better protected from subsequent herbivore attack in laboratory trials. Root nicotine production is activated by an endogenously‐produced signal, jasmonic acid (JA), which is synthesized in response to leaf damage and either directly through transport or indirectly via another, as yet unknown signal, increases JA pools and nicotine biosynthesis in the roots. The addition of JA or its methyl ester (MJ) to plants stimulates nicotine production in the same way that leaf damage does. In this study I use MJ to elicit the induced defense without wounding and describe a new character state for this induced defense: the allometrically determined setpoint. Plants were induced with 45 μg of MJ, once or in different combinations of 2 or 3 times during a 21‐day period of vegetative growth, allowed 7 days between elicitations for the response to relax, and harvested during one of 4 harvests in order to quantify biomass and whole‐plant nicotine pools. For plants induced only once, the largest induced change in whole‐plant nicotine pools occurred during the second induction period, when elicitation increased nicotine pools by 5.99 mg, approximately 87% more than either the first or third induction periods. However, plants induced once had the same whole‐plant nicotine pools at the end of the experiment regardless of whether they were induced during the highly responsive second period or during the less responsive first and second induction periods. Sequential elicitations consistently increased nicotine pools, but after 3 inductions, the nicotine pools were not significantly higher than those in plants which had been induced twice; plants can only increase their nicotine pools in response to 2 inductions when grown under these conditions. These results suggest that this plant has allometrically‐determined setpoints for this induced defense which are determined by the number of times a plant's wound‐signal cascade is stimulated, rather than by the quantity of nicotine synthesized during an induction episode.
Retention Time of Seeds in Bird Guts: Costs and Benefits for Fruiting Plants and Frugivorous Birds
Authors: FUKUI AKIKO
Published: February 2005

Abstract Fruiting plants and frugivorous birds are known to interact. In endozoochory, frugivorous birds consume fruits and subsequently disperse seeds. It follows that fruit characteristics would have evolved to allow birds to consume fruits easily. However, one's benefit does not always mean the other's. There are several conflicts between fruiting plants and frugivorous birds in terms of nutrient content, retention time and number of seeds in a fecal pellet. Retention time of seeds in guts is particularly interesting. Longer retention time benefits plants directly by increasing seed dispersal distance but may involve indirect costs through birds' preference by reducing their consumption. To understand the exact role of seed dispersers in the reproductive success of fruiting plants, we should pay more attention to the possible conflicts between fruiting plants and frugivorous birds.
What Can We Learn about Seed Dispersal from Seed Trap Experiments at Fruiting Trees? Efficiency of Dispersal Traits
Authors: OKAMOTO MOTOHARU
Published: February 2005

Abstract A new index that measures efficiency of dispersal traits is proposed to replace the “removal rate.” Escape from the mother plant is essential for survival of seeds. The percentage of escaped seed is therefore a good indicator of the efficiency of dispersal. However, seed trap experiments measure only an apparent rate of escaped seed (AES), because of contamination by seeds from other conspecific trees. If we assume that as many seeds of the experimental tree are carried to conspecific trees as travel in the reverse direction, AES is a good estimate of seeds escaped from both the mother and conspecific fruiting trees. This may be called the rate of effective escaped seeds (EES), because the seeds carried to conspecific trees have no more meaning for survival than those defecated beneath the mother tree. As an example, two fruiting traits, synchronous ripening and extended ripening, were compared for their efficiencies in terms of AES(? EES) at an urban botanical garden for two seasons. In the extended ripening species, about 80 percent of seeds were successfully dispersed away from the parent plant or conspecific plants for both seasons, but the percentages fluctuated, between 60 and 86, in the synchronous one.
Microgeographic Allozyme Variation in Yushan Cane (Yushania niitakayamensis; Poaceae)
Authors: HSIAO JU‐YING , WANG BING‐SHIN , RIESEBERG LOREN H.
Published: February 2005

Abstract Allozyme variation was analyzed in 180 individuals of Yushan cane from adjacent sun and shade microhabitats from three localities on Mt. Hohuan in Taiwan. Significant genetic differentiation according to microhabitat was found for both single and multi‐locus comparisons. Moreover, sun sub‐populations from different localities clustered together in a neighbor‐joining tree based on isozyme genetic distances, as did shade sub‐populations. These data not only imply significant local adaptation for different habitats in phenotypically plastic Yushan cane, but also suggest that diversifying selection is acting on allozyme loci or closely linked traits.
Plastic Responses to Nutrient and Light Intensity Gradients in Populations of Oxalis corniculata L. (Oxalidaceae)
Authors: SHIBAIKE HIROYUKI , ISHIGURI YOSHIO , KAWANO SHOICHI
Published: February 2005

Abstract Plastic responses of 12 morphological and life history traits to different nutrient and light intensity gradients were studied in five populations of Oxalis corniculata, a clonal perennial with creeping horizontal runners. This species comprises two floral morphs, homostyled and long‐styled, with different breeding systems. In controlled nutrient and light intensity experiments, 98 of 120 traits exhibited significant plastic responses in one‐way ANOVA; significant population × treatment interaction terms in two‐way ANOVA were found for 16 of 24 traits. Marked growth responses were noted in the plants grown along different environmental gradients. Reduced light availability decreased reproductive allocation and enhanced vertical and horizontal stems. To investigate the plastic responses of homostyled and long‐styled populations in further detail, patterns and amounts of plastic responses across 12 traits were also quantified. Significantly different overall amounts of plastic responses among the populations were found along the nutrient gradient. In addition, we also evaluated the foraging ability of these populations in terms of spacer length and branching intensity. There were three different types of foraging behaviors along the light intensity gradient. Homostyled populations generally showed small amounts of plastic response and foraging ability; in contrast, long‐styled populations tended to exhibit larger amounts of plastic response and greater foraging ability.
A Preliminary Study of the Pollination Ecology ofPedicularisin the Chinese Himalaya
Authors: MACIOR LAZARUS WALTER , YA TANG
Published: February 2005

AbstractThe pollination ecology of fourteen species ofPedicularis(Scrophulariaceae) was studied in the subalpinealpine zone of the Sichuan Himalaya. Bumblebees (BombusLatr.) sternotribically pollinated rostrate, nectarless species with very long corolla tubes by scraping pollen. Pollinators on short‐tubed, nectarless, rostrate species scraped or vibrated pollen, and nectariferous species were pollinated nototribically by nectar foragers or sternotribically by pollen foragers. Stigmas contacted residual pollen in the midline of the insect body. No evidence of lepidopteran pollination was found in anyPedicularisspecies.Pedicularisfloral structure and function are considered to have coevolved with foraging selection by bumblebees, but pollination syndromes are not specific for a single bumblebee species nor areBombusforagers restricted to a single plant species. Analysis of corbicular pollen loads of foragers onPedicularisrevealed a moderate degree of flower constancy, especially among foragers on nectarless flowers, probably contributing to speciation in the genus. Up to ninePedicularisspecies flowered sympatrically and synchronously, and some species exhibited microhabitat selection. No putative hybrids were identified. Concepts of floral evoution inPedicularisare in need of revision in light of new evidence presented here.
Natural Variation in Flowering Time among Populations of the Annual Crucifer Arabidopsis thaliana
Authors: HAMMAD IBTISAM , VAN TIENDEREN PETER H.
Published: February 2005

Abstract Genetic variation in flowering time was studied in four natural populations of Arabidopsis thaliana, using greenhouse experiments. Two populations from ruderal sites flowered early, two others from river dykes late. However, the late flowering plants flowered almost as early as the others after cold treatment of the seeds. The observed differences in flowering time have consequences for the potential life cycles of plants in the field. Plants from ruderal sites can be summer or winter annual, perhaps even have two generations per year. The strong response to cold treatment of plants from the dyke vegetations makes their life cycle strictly annual. Segregation analyses of the F2‐s from crosses between early and late plants suggests that this variation in flowering time was genetic, with a dominant major gene for late flowering. Lateness in combination with vernalization responsiveness appears to be mostly due to a single gene in A. thaliana. It is hypothesized that early flowering ecotypes have evolved from late flowering ecotypes in different habitats by a loss mutation in the inhibitory mechanisms that delays flowering until after a period of low temperatures.
Genetic Variation and Relationships of Japanese Populations of Oxalis corniculata L. (Oxalidaceae) Detected by Random Amplified Polymorphic DNA (RAPD)
Authors: SHIBAIKE HIROYUKI , ISHIGURI YOSHIO , KAWANO SHOICHI
Published: February 2005

Abstract RAPD analysis was applied to estimate the genetic variability in Japanese populations of Oxalis corniculata. This species comprises two floral morphs, homostyled and long‐styled, with different breeding systems (i.e., autogamy in the homostyled populations and mixed mating in the long‐styled populations). The number of RAPD phenotypes tended to be larger in homostyled populations than in long‐styled ones, and genetic diversity expressed by Simpson's indices of diversity was also generally larger in the former than in the latter.

To examine the effects of breeding system on the levels of genetic differentiation among populations, two‐ and one‐level hierarchical variance partitionings were performed by the analysis of molecular variance (AMOVA). In two‐level AMOVA, significant variance component between the floral morphs was observed. In one‐level AMOVA, the proportions of variance partitioned among populations within each floral morph and among individuals within populations were similar in the homostyled and long‐styled populations, despite the difference in breeding system.

To obtain insight into the relationships among individuals and/or populations, principal co‐ordinate analysis using 184 individuals (PCOA), and clustering analysis of 12 populations (UPGMA) were performed. PCOA indicated that the range of variation for homostyled individuals was more inclusive than that for long‐styled ones. A UPGMA dendrogram that consisted of two clusters showed that the long‐styled populations were nested in the homostyled ones.
Crown Architecture of Two Understory Palm Species of the Genus Licuala in a Tropical Rain Forest
Authors: TAKAHASHI KOICHI , KOHYAMA TAKASHI
Published: February 2005

Abstract The crown architecture of two understory palms, Licuala arbuscula and L. bintulensis, was studied in a tropical lowland rain forest in West Kalimantan, Indonesia. The two species had only stagnant stems and developed a hemispherical crown formed with long petioles and fan‐shaped leaf blades. Petioles at leaf emergence stood vertically, while petioles of older leaves were bent downward. Leaves were concentrated on the top of the crown. The leaf blade deflected ca. 40° from the horizon to the inside of crown when the petiole stood vertically. Because the divergence angle between the leaf blade and its petiole did not change, the zenith angle of the leaf blade changed with that of the petiole. This divergence angle between leaf blade and petiole allowed the formation of a compact foliage clump with less overlap at the top of the crown, and the horizontal expansion of leaves at the middle of the crown. The size and number of leaves within the crown increased with crown development, and the ratio of the petiole to the leaf blade length increased. This enabled the two palms to extend their assimilative area over the non‐photosyn‐thetic supportive part as petioles in the small size stage and to avoid the overcrowding of leaves within a crown with crown development. These results suggest that the two understory palms develop crowns as to avoid self‐shading through adjusting the divergence angle between leaf blade and petiole and through the allometry between them.
Aerial Seed Bank and Intra‐population Variability in Germinative Strategies of Verbascum phlomoides L.
Authors: PUECH SUZETTE , RIBANNIER CORINNE , MARTIN ARNAUD
Published: February 2005

Abstract Study of germination using fresh seeds and seeds from an aerial seed bank of a young Verbascum phlomoides population revealed the existence of primary dormancy that blocks immediate germination and of substantial variations in the subsequent germination capability. The heterogeneity of desynchronized individual responses in a species with a high germination capacity would make it possible for the descendants of one or more individuals to occupy a disturbed site. Exposure to cold followed by a return to the light accelerating germinative response would appear to enhance late spring germination.
Chemical Divergence in Floral Scents of Magnolia and Allied Genera (Magnoliaceae)
Authors: AZUMA HIROSHI , TOYOTA MASAO , ASAKAWA YOSHINORI , YAMAOKA RYOHEI , GARCIA‐FRANCO JOSE G. , DIERINGER GREGG , THIEN LEONARD B. , KAWANO SHOICHI
Published: February 2005

Abstract Floral scents emitted from Magnolia, Michelia and Liriodendron taxa native to or cultivated in North America, Mexico and Japan were collected by the headspace method and analyzed using gas chromatography – mass spectrometry (GC‐MS). Volatile compounds are widespread in the flowers of angiosperms and the chemical property of the scents can be distinguished in taxa. For example, the primary chemical in the scent of Magnolia virginiana growing in Louisiana (U.S.A.) is linalool, whereas in Maryland (U.S.A.) population flowers emit 2‐phenylethanol. The flowers of M. grandiflora and M. tamaulipana both emit a number of monoterpenes, mainly geraniol derivatives, but scents of M. pyramidata yield mainly fatty acid esters. Caryophyllene is exclusively emitted by M. sieboldii ssp. japonica, isobutyl acetate by Michelia figo, and 1,2‐dimethoxybenzene by M. salicifolia. The flowers of L. tulipifera and L. chinense emit mainly hydrocarbon‐terpenoids, the former dominated by limonene, the latter by afarnesene. In some closely related disjunct taxa distributed in North America and eastern Asia the floral scents closely resemble each other, e.g., Magnolia tripetala (North America) and M. hypoleuca (Japan) both strongly emit methyl benzoate. Another set of disjunct taxa, M. acuminata (North America) and M. heptapeta (China) both exclusively emit pentadecane, a hydrocarbon. In some species of Magnolia, volatile compounds present in floral scents are also emitted in damaged leaves. This suggests these chemicals play different roles in various plant organs (deter leaf herbivores, attract parasitoids, attract insects to flowers, etc.).
Marked Spatial Genetic Structure in Three Populations of a Weedy Fern, Pteris multifida Poir., and Reestimation of Its Selfing Rate
Authors: MURAKAMI NORIAKI , NISHIYAMA TOMOAKI , SATOH HISASHI , SUZUKI TAKESHI
Published: February 2005

Abstract Allozyme markers were used to characterize spatial genetic structure for the weedy fern Pteris multifida within three populations growing on the man made stone walls. Even visually distinct genetic substructures were observed in all the examined populations. Spatial autocorrelation analysis using Moran's /indicated that the patch size of P. multifida was as small as 4–9 m. Estimation of outcrossing rate is known to be severely biased downwards if the presence of spatial genetic structure is ignored. Mating system of this fern species was reported as mixed (mean selfing rate: 0.435). However, fixation indexes calculated in small patches less than 3–10 m wide were not significantly different from Hardy‐Weinberg equilibrium and thus P. multifida's mating system was considered to be outcrossing.
Demographic Genetics of the Japanese Beech, Fagus crenata, at Ogawa Forest Preserve, Ibaraki, Central Honshu, Japan. I. Spatial Genetic Substructuring in Local Populations
Authors: KITAMURA KEIKO , SHIMADA KENICHI , NAKASHIMA KIYOSHI , KAWANO SHOICHI
Published: February 2005

Abstract The demographic genetic substructuring of local Fagus crenata populations at Ogawa Forest Preserve, Ibaraki Prefecture, central Honshu, Japan, was analyzed by means of demographic parameters and genetic markers using protein polymorphisms (allozymes). All individuals, including seedlings, various sizes of juveniles, and adult trees within two transects were mapped; size‐class structures were analyzed based on DBH and DGH measurements, and their genotypes determined for 11 different allozyme loci (a total of 46 alleles), i.e., Aap1(3 alleles), Adh (3), Amy2 (6), Dia (4), Fum (3), Got1 (5), Got2 (3), Lap (6), Pgi (4), Pgm1 (4), and Pgm2 (5).

Critical analyses were conducted to test whether genetic substructuring patterns in these two transects are correlated with the underlying environmental regimes of the habitats. Measurements of relative light intensity, soil moisture, pH, and C‐N content were made for each block in the two transects. Principal component analyses (PCA) of the environmental variables revealed that two components (Z1 and Z2) were closely related to variations in light intensity and soil moisture. The projection diagrams obtained by the environmental variables were then overlaid with the spatially localized patterns of size‐classes and genotype distributions of 11 allozyme loci examined.

The results revealed that genetic variations are pooled in the juvenile trees of certain size‐classes, consisting of overlapping generations which occur in the particular sites characterized by environmental regimes. Throughout the regeneration processes, new genetic diversities are introduced through seedlings with new genotypes into the population.
Markoff chain modelling of NDI techniques
Authors: ROCHA M. M. , SCHUËLLER G. I.
Published: February 2005

A procedure for non‐destructive inspection by taking into account the effects of stochastic fatigue crack growth is presented. For this purpose a Markoff chain model is used to update the crack statistics, allowing an efficient computational implementation and a clear account of the involved concepts. In this context, perfect and imperfect removal of cracks, respectively, are considered, which represent idealizations defining bounds for actual situations.
Finite‐element analysis of fatigue crack closure under plane strain conditions: stabilization behaviour and mesh size effect
Authors: LEE H.‐J. , SONG J.‐H.
Published: February 2005

An elastic–plastic finite‐element analysis of fatigue crack closure is performed for plane strain conditions. The stabilization behaviour of crack opening level and the effect of mesh size on the crack opening stress are investigated. It has been well reported that the crack opening level under plane stress conditions becomes stable after the crack advances beyond the initial monotonic plastic zone. In order to obtain a stabilized crack opening level for plane strain conditions, the crack must be advanced through approximately four times the initial monotonic plastic zone. The crack opening load tends to increase with the decrease of mesh size. The mesh size nearly equal to the theoretical plane strain cyclic plastic zone size may provide reasonable numerical results comparable with experimental crack opening data. The crack opening behaviour is influenced by the crack growth increment and discontinuous opening behaviour is observed.
Strong Tests of Developmental Ordering Hypotheses: Integrating Evidence From the Second Moment
Authors: Dixon James A.
Published: February 2005

Developmental ordering is a fundamental prediction in developmental science. However, tests of ordering hypotheses are not generally available for continuously developing variables. One promising test of developmental ordering, the shape of the relationship between 2 variables, requires that changes in each underlying variable are captured equally well across the developmental span (measures are linearly related to the variables). If either measure is more sensitive to earlier or later developmental changes in the underlying variable, the shape of the relationship changes radically. The article demonstrates that the viable alternative hypotheses for an observed developmental relationship require specific types of nonlinearity in measurement and, therefore, have testable predictions for the residuals (the second moment). Ordering as evidence in developmental science is discussed.
Corporeal Ontology: Beyond Mind-Body Dualism?
Authors: Jenkins Laura
Published: February 2005

The definition and boundaries of the political have received considerable attention in recent times in political science, perhaps as a result of the wavering confidence in the scientific status of the knowledge that the discipline creates. However, a conspicuous absence continues to haunt mainstream political science, one that if rectified threatens, in some ways, to broaden both the nature of the political still further and to challenge the very division of knowledge into the social and natural sciences. This absence is the human body and this article seeks to ask after its exclusion and to suggest that its exclusion is both political and needs rectifying. I argue that the exclusion of the body in political science is a consequence of an inadequate ontological short cut, which is accepted (mostly) unquestioningly by political analysts and which has severe epistemological and methodological consequences. I suggest that a more reflective consideration of the body and its dynamic interplay with the mind could offer the discipline a greater understanding of the human subject, as well as alter power-knowledge relations.
Making Hay … or Clutching at Ontological Straws? Notes on Realism, ‘As-If-Realism’ and Actualism
Authors: Hay Colin
Published: February 2005

Stuart McAnulla provides an eloquent defence of a particular variant of critical realism, suggesting that it provides a more appropriate set of ontological foundations for the kind of critical political analysis I espouse than the ontological actualism he attributes to me. In this rejoinder, whilst welcoming McAnulla's important intervention in the debate, I defend myself against his charge of actualism (if the attribution of an ontology to an author can be regarded as a charge), whilst indicating how the ‘as-if-realism’ that perhaps better reflects my ontological assumptions is perfectly compatible with critical political analysis. In so doing I caution against ontological evangelism, the notion that only ‘real’ entities can be causal, and the appeal to structures (like patriarchy) as causes. I conclude by reflecting on the complex and seldom discussed relationship between experience and ontology.
British Higher Education and the Bologna Process: An Interim Assessment
Authors: Furlong Paul
Published: February 2005

The Bologna process has attracted considerable attention and some misunderstanding. This article describes the development of the reform process since 1998, considers how it has been agreed and implemented and seeks to explain Bologna in the context of wider European Union responses to global issues of competitiveness and free trade. The article argues that the significance of Bologna lies not only in the reforms agreed and implemented, but also in the justification it provides for varying national adaptations in major states. These adaptations are driving a broader process of change amongst a large number of signatories, whose capacity to affect the detail of the reform is limited. The article identifies and analyses UK policy, and draws some conclusions about the implications of the process for the teaching of politics in UK universities.
The UK and the Euro: Debating the British Decision
Authors: Mulhearn Chris , Vane Howard R.
Published: February 2005

This article seeks to inform and enliven the debate on whether or not Britain should join the euro. The central focus of the article involves interviews with two leading economists, Professor Willem Buiter (Chief Economist and Special Counsellor to the President, European Bank for Reconstruction and Development) who strongly supports the case for joining, and Professor Patrick Minford (Professor of Applied Economics, Cardiff Business School) who takes the opposite stance. The article begins with an introduction which places the interviews in context and concludes with a final section summarising the central points of commonality and departure arising in the interviews with Professors Buiter and Minford.