bluuebunny/crossref_metadata_2025 huggingface dataset:
Patterns and determinants of potential carbon gain in the C3evergreenYucca glauca(Liliaceae) in a C4grassland
Authors: Maragni Laura A. , Knapp Alan K. , McAllister Christine A.
Published: April 2006

Yucca glaucais a C3evergreen rosette species locally common in the C4‐dominated grasslands of the central Great Plains. Most congeners ofY. glaucaare found in deserts, andY. glauca’smorphological similarities to desert species (steeply angled leaves, evergreen habit) may be critical to its success in grasslands. We hypothesized that the evergreen habit ofY. glauca,coupled with its ability to remain physiologically active at cool temperatures, would allow this species to gain a substantial portion of its annual carbon budget when the C4grasses are dormant. Leaf‐level gas exchange was measured over an 18‐mo period at Konza Prairie in northeast Kansas to assess the annual pattern of potential C gain. Two short‐term experiments also were conducted in which nighttime temperatures were manipulated to assess the cold tolerance of this species. The annual pattern of C gain inY. glaucawas bimodal, with a spring productive period (maximum monthly photosynthetic rate = 21.1 ± 1.97 μmol·m−2·s−1) in March through June, a period of midseason photosynthetic depression, and a fall productive period in October (15.6 ± 1.25 μmol·m−2·s−1). The steeply angled leaves resulted in interception of photon flux density at levels above photosynthetic saturation throughout the year. Reduced photosynthetic rates in the summer may have been caused by low soil moisture, but temperature was strongly related (r2= 0.37) to annual variations in photosynthesis, with nocturnal air temperatures below −5°C in the late fall and early spring, and high air temperatures (>32°C) in the summer, limiting gas exchange. Overall, 31% of the potential annual carbon gain inY. glaucaoccurred outside the “frost‐free” period (April–October) at Konza Prairie and 43% occurred when the dominant C4grasses were dormant. Future climates that include warmer minimum temperatures in the spring and fall may enhance the success ofY. glaucarelative to the C4dominants in these grasslands.
Genetic variation in chloroplast and nuclear ribosomal DNA in Utah juniper (Juniperus osteosperma, Cupressaceae): evidence for interspecific gene flow
Authors: Terry Randall G. , Nowak Robert S. , Tausch Robin J.
Published: April 2006

Geographic patterns of genetic variation in chlorolast (cpDNA) and nuclear ribosomal (nrDNA) DNA were examined to test the hypothesis of hybridization between Juniperus osteosperma and Juniperus occidentalis in the Great Basin of western Nevada. Noncoding DNA from the trnL‐trnF intergenic spacer and the trnL intron of the chloroplast genome was sequenced from seven populations of J. osteosperma and four populations of J. occidentalis sampled over a large proportion of their respective ranges. An adenine nucleotide at position 436 in the aligned sequence and within a Tru 9I restriction site was found to be present in individuals of J. osteosperma sampled from western Colorado and central Utah, but absent in sequences of J. osteosperma sampled from central and western Nevada and all sequences of J. occidentalis. Two hundred fourteen individuals from 34 populations of J. osteosperma and J. occidentalis were then screened for cpDNA haplotype by Tru 9I digestion of the trnL‐trnF polymerase chain reaction (PCR) product. Two cpDNA haplotypes were evident, each consisting of restriction fragment profiles that differed solely with respect to the presence or absence of the Tru 9I site encompassing the adenine nucleotide at position 436. One of these haplotypes was monomorphic in J. occidentalis and exhibited a decreasing frequency in J. osteosperma with increasing geographic distance from J. occidentalis in west‐central Nevada. Geographic patterns in nuclear ribosomal DNA (nrDNA) variation were examined by restriction fragment analysis and, although spatially more restricted, exhibited patterns of clinal variation similar to those observed in cpDNA haplotype. Genetic relationships based on DNA sequences and geographic patterns of genetic variation in chloroplast and nuclear ribosomal DNA are consistent with morphology in suggesting interspecific gene flow between J. occidentalis and J. osteosperma.
The influence of microgravity and spaceflight on columella cell ultrastructure in starch‐deficient mutants of Arabidopsis
Authors: Guisinger Mary M. , Kiss John Z.
Published: April 2006

The ultrastructure of root cap columella cells was studied by morphometric analysis in wild‐type, a reduced‐starch mutant, and a starchless mutant of Arabidopsis grown in microgravity (F‐μg) and compared to ground 1g (G‐1g) and flight 1g (F‐1g) controls. Seedlings of the wild‐type and reduced‐starch mutant that developed during an experiment on the Space Shuttle (both the F‐μg samples and the F‐1g control) exhibited a decreased starch content in comparison to the G‐1g control. These results suggest that some factor associated with spaceflight (and not microgravity per se) affects starch metabolism. Elevated levels of ethylene were found during the experiments on the Space Shuttle, and analysis of ground controls with added ethylene demonstrated that this gas was responsible for decreased starch levels in the columella cells. This is the first study to use an on‐board centrifuge as a control when quantifying starch in spaceflight‐grown plants. Furthermore, our results show that ethylene levels must be carefully considered and controlled when designing experiments with plants for the International Space Station.
Frequency of somaclonal variation in plants of black spruce (Picea mariana, Pinaceae) and white spruce (P. glauca, Pinaceae) derived from somatic embryogenesis and identification of some factors involved in genetic instability
Authors: Tremblay Laurence , Levasseur Caroline , Tremblay Francine M.
Published: April 2006

Plants of black spruce (Picea mariana, N = 7047 individuals) and white spruce (P. glauca, N = 3995 individuals) were regenerated from a total of 87 clones over a 5‐yr period by somatic embryogenesis to study factors that might be associated with the appearance of variant phenotypes. Morphological evaluation of the plants showed several types of variation. These variations were grouped into nine types: dwarfism (type A), reduced height with various form anomalies (types B, C, and D), needle fasciation (type E), abnormality in tree architecture (type F), variegata phenotype (type G), and plants with an overall regular morphology but smaller than normal plants (type H). Plagiotropic plants were also observed (type I). Each plant from types A to H (except type C where no plants survived more than 6 mo) had retained its phenotype over 4–5 yr of growth. Some of the variant types could be related to chromosomic instability: chromosome counts showed aneuploid cells for type‐A and type‐D plants. The type I (plagiotropism) was not related to genetic instability but rather to physiological disorders. In total, spruce variants of types A–H were obtained at relatively low frequencies, i.e., 1.0% (39/3995) for white spruce and 1.6% (110/7047) for black spruce. Statistical analyses, conducted with family, clone, and time in maintenance as variables, showed that clone was the most important source of genetic instability followed by time in maintenance.
The cytoplast concept in dividing plant cells: cytoplasmic domains and the evolution of spatially organized cell division
Authors: Pickett‐Heaps Jeremy D. , Gunning Brian E. S. , Brown Roy C. , Lemmon Betty E. , Cleary Ann L.
Published: April 2006

The unique cytokinetic apparatus of higher plant cells comprises two cytoskeletal systems: a predictive preprophase band of microtubules (MTs), which defines the future division site, and the phragmoplast, which mediates crosswall formation after mitosis. We review features of plant cell division in an evolutionary context and from the viewpoint that the cell is a domain of cytoplasm (cytoplast) organized around the nucleus by a cytoskeleton consisting of a single “tensegral” unit. The term “tensegrity” is a contraction of “tensional integrity” and the concept proposes that the whole cell is organized by an integrated cytoskeleton of tension elements (e.g., actin fibers) extended over compression‐resistant elements (e.g., MTs).

During cell division, a primary role of the spindle is seen as generating two cytoplasts from one with separation of chromosomes a later, derived function. The telophase spindle separates the newly forming cytoplasts and the overlap between half spindles (the shared edge of two new domains) dictates the position at which cytokinesis occurs. Wall MTs of higher plant cells, like the MT cytoskeleton in animal and protistan cells, spatially define the interphase cytoplast. Redeployment of actin and MTs into the preprophase band (PPB) is the overt signal that the boundary between two nascent cytoplasts has been delineated. The “actin‐depleted zone” that marks the site of the PPB throughout mitosis may be a more persistent manifestation of this delineation of two domains of cortical actin. The growth of the phragmoplast is controlled by these domains, not just by the spindle. These domains play a major role in controlling the path of phragmoplast expansion. Primitive land plants show different morphological changes that reveal that the plane of division, with or without the PPB, has been determined well in advance of mitosis.

The green alga Spirogyra suggests how the phragmoplast system might have evolved: cytokinesis starts with cleavage and then actin‐related determinants stimulate and positionally control cell‐plate formation in a phragmoplast arising from interzonal MTs from the spindle. Actin in the PPB of higher plants may be assembling into a potential furrow, imprinting a cleavage site whose persistent determinants (perhaps actin) align the outgrowing edge of the phragmoplast, as in Spirogyra. Cytochalasin spatially disrupts polarized mitosis and positioning of the phragmoplast. Thus, the tensegral interaction of actin with MTs (at the spindle pole and in the phragmoplast) is critical to morphogenesis, just as they seem to be during division of animal cells. In advanced green plants, intercalary expansion driven by turgor is controlled by MTs, which in conjunction with actin, may act as stress detectors, thereby affecting the plane of division (a response clearly evident after wounding of tissue). The PPB might be one manifestation of this strain detection apparatus.
Destruction of lichen chemical defenses by a fungal pathogen
Authors: Lawrey James D. , Torzilli Albert P. , Chandhoke Vikas
Published: April 2006

Lichen secondary metabolites are known to inhibit various animal consumers and pathogenic microorganisms. Nevertheless, many obligate fungal pathogens have evolved a tolerance to these inhibitory lichen compounds. We recently discovered a new lichen pathogen in the fungal genus Fusarium that is not only tolerant of lichen compounds but also able to degrade many of these compounds. This organism was discovered in field investigations of a different lichenicolous fungus, Marchandiomyces corallinus, which was found growing on lichens (Lasallia papulosa and L. pensylvanica) that normally inhibit its growth. Subsequent experiments established that M. corallinus is found on Lasallia species only when Fusarium is also present. We hypothesized that Fusarium altered the inhibitory chemistry of Lasallia spp. and permitted colonization by M. corallinus. A laboratory experiment to test this hypothesis demonstrated that sterilized tissues of Lasallia papulosa exposed to Fusarium for 30 d are readily degraded by M. corallinus; control tissues left in sterile water for 30 d continue to inhibit growth of M. corallinus. High performance liquid chromatography (HPLC) established that the lichen compound lecanoric acid, one of several lichen compounds that inhibit growth of M. corallinus, is degraded by extracellular enzymes produced by this newly discovered Fusarium. Taken together, our results demonstrate that enzymatic degradation of lichen compounds permits colonization of lichens by fungi that would otherwise be chemically excluded.
Pollen competition as a reproductive isolating mechanism between two sympatric Hibiscus species (Malvaceae)
Authors: Klips Robert A.
Published: April 2006

Differences in pollen tube growth rates (certation) between heterospecific (foreign) and conspecific pollen may strongly influence whether hybrid offspring are produced after mixed pollen loads are delivered to a stigma. For both members of a sympatric species pair, Hibiscus moscheutos and H. laevis, pollination by pure loads of foreign pollen resulted in fruit set that was not significantly different from conspecific pollination, indicating that pure loads of foreign pollen could readily result in hybrid offspring. However, the number of seeds per fruit from pure foreign pollinations was significantly less than that of pure conspecific pollination. Simultaneous mixed pollination resulted in a proportion of hybrid seeds (detected by an electrophoretic marker enzyme) that was significantly lower than expected based upon the capacity of foreign pollen to effect fertilization when applied in pure pollinations. After these 50/50% pollen mixtures were applied to stigmas, 8.0 and 7.4% hybrids were produced when H. moscheutos and H. laevis were the ovule parents, respectively. For these Hibiscus species, pollen competition appears to function as a barrier to hybridization that is of moderate intensity compared with similar barriers occurring between other recently studied sympatric species pairs.
Sex allocation and reproductive success in the andromonoecious perennial Solanum carolinense (Solanaceae). I. Female success
Authors: Elle Elizabeth
Published: April 2006

Relative allocation of resources to growth vs. reproduction has long been known to be an important determinant of reproductive success. The importance of variation in allocation to different structures within reproductive allocation is somewhat less clear. This study was designed to elucidate the importance of allocation to vegetative vs. reproductive functions, and allocation within reproductive functions (sex allocation), to realized female success in an andromonoecious plant, Solanum carolinense. Allocation measurements were taken on plants in experimental arrays exposed to natural pollination conditions. These measurements included total flower number, the proportion of flowers that were male, flower size, and vegetative size. Flower number explained the majority of the variation among individuals in their success—that is, there was strong selection for increased flower production. There was also selection to decrease the proportion of flowers that were male, but neither flower size nor vegetative size (a measure of overall resource availability) were direct determinants of female success. After Bonferroni corrections for multiple comparisons, most phenotypic correlations among the traits measured were nonsignificant. Thus, in this andromonoecious species there is not a strong relationship between resource availability (vegetative size) and female success, and female success is instead determined by the relative production of the two different flower types.
Three groups of species in Petunia sensu Jussieu (Solanaceae) inferred from the intact seed morphology
Authors: Watanabe Hitoshi , Ando Toshio , Nishino Eisho , Kokubun Hisashi , Tsukamoto Tatsuya , Hashimoto Goro , Marchesi Eduardo
Published: April 2006

The intact seed surface morphology in 45 taxa of Petunia sensu Jussieu native to South America (Petunia sensu Wijsman plus Calibrachoa) was compared under scanning electron microscopy. The existence of three groups of species, differentiated in terms of seed morphology, was revealed as follows: (1) all species of Petunia sensu Wijsman, having coarse wavy middle lamellae and anticlinal walls; (2) Calibrachoa parviflora and C. pygmaea, having fine wavy middle lamellae embedded in straight anticlinal walls; and (3) the other species of Calibrachoa, having straight middle lamellae and anticlinal walls. Close relationships between seed morphology and the other characteristics observable in the groups of species are discussed.
Phylogeny of Rubus (rosaceae) based on nuclear ribosomal DNA internal transcribed spacer region sequences
Authors: Alice Lawrence A. , Campbell Christopher S.
Published: April 2006

We used nuclear ribosomal DNA internal transcribed spacer region (ITS 1 − 5.8S − ITS 2; ITS) sequences to generate the first phylogeny of Rubus based on a large, molecular data set. We sampled 57 taxa including 20 species of subgenus Rubus (blackberries), one to seven species from each of the remaining 11 subgenera, and the monotypic and closely related Dalibarda. In Rubus, ITS sequences are most informative among subgenera, and variability is low between closely related species. Parsimony analysis indicates that Rubus plus Dalibarda form a strongly supported clade, and D. repens may nest within Rubus. Of the subgenera with more than one species sampled, only subgenus Orobatus appears monophyletic. Three large clades are strongly supported: one contains all sampled species of nine of the 12 subgenera; another includes extreme Southern Hemisphere species of subgenera Comaropsis, Dalibarda, and Lampobatus; and a third clade consists of subgenus Rubus plus R. alpinus of subgenus Lampobatus. Rubus ursinus appears to be a hybrid between a close relative of R. macraei (subgenus Idaeobatus, raspberries) and an unidentified subgenus Rubus species. ITS sequences are generally consistent with biogeography and ploidy, but traditionally important morphological characters, such as stem armature and leaf type, appear to have limited phylogenetic value in Rubus.
Molecular systematics of Clerodendrum (Lamiaceae): ITS sequences and total evidence
Authors: Steane Dorothy A. , Scotland Robert W. , Mabberley David J. , Olmstead R. G.
Published: April 2006

Thirty‐three species of Clerodendrum s.l. and five outgroup genera were included in a sequence analysis of internal transcribed spacers of the nuclear ribosomal DNA. The results of the cladistic analysis were compared to and combined with cpDNA restriction site data from a previous study. All molecular data identified four major clades within Clerodendrum s.l. and showed the genus to be polyphyletic. Clerodendrum s.s., minus Konocalyx and Cyclonema, is monophyletic and the genus should be restricted to this group. Cyclonema and Konocalyx form a clade distinct from Clerodendrum s.s., which has been recognized as Rotheca Raf.
Expression of pattern in plants: combining molecular and calculus‐based biophysical paradigms
Authors: Green Paul B
Published: April 2006

Pattern formation in plant meristems occurs across a broad scale. At the topographical level (large scale), tissue folding in the meristem is responsible for the initiation of new organs in specific phyllotactic patterns and also determines organ shape. At the cellular level (small scale), oriented cell division and microtubule‐based cellulose reinforcement control cell pattern and growth direction. I argue here that structural specification at each scale is highly efficient if the pertinent gene activity is manifested in two complementary biophysical categories. At large scale, one category is the tendency of the formative tissue to fold with a certain spatial periodicity determined by its material properties (e.g., bending stiffness from cellulose content). This latent tendency is formalized in a differential equation for physical buckling. The second category at this scale comprises boundary conditions that specify how the latent tendency is manifested as topography: whether tissue humps occur as whorls or Fibonacci spirals. This versatile combinatorial format accounts for the relative stability of alternative organ patterning as well as alternative organ shaping (e.g., stamens vs. carpels). It also accounts for the structural shifts seen in normal development and after mutation or chemical/physical intervention. At small scale, the latent differential activity is the tendency for groups of dividing cells to co‐align their cytoskeletons. The curvature of the surface opposes this tendency. The least curved part of a new primordium is its quasicylindrical midportion. There, by aligning microtubules and cellulose coherently around the organ, a new growth direction is set. Thus large‐scale buckling produces curvature variation, which, in turn, affects the localization and orientation of the cytoskeleton. This scheme for the coherent production of diverse geometrical features, involving calculus at two structural levels, is supported by complex organogenetic responses to simple physical intervention. Also, many morphological alternatives, wild type vs. mutant, reflect single changes in parameters in this differential‐integral format.
Canny's compensating pressure theory fails a test
Authors: Stiller Volker , Sperry John S
Published: April 2006

Canny's compensating pressure theory for water transport (American Journal of Botany 85: 897–909) has evolved from the premise that cavitation pressures are only a few tenths of a megapascal negative (approximately −0.3 MPa). In contradiction, “vulnerability curves” indicate that xylem pressures can drop below −3 MPa in some species without causing a loss of hydraulic conductivity. Canny claims these curves do not measure the limits to negative pressure by cavitation, but rather the limits to the compensating tissue pressure that otherwise quickly refills cavitated conduits. Compensating pressure is derived from the turgor pressure of the living cells in the tissue. To test this claim, we compared vulnerability curves of Betula nigra stems given three treatments: (1) living control, (2) killed in a microwave oven, and (3) perfused with a −1.5 MPa (10% w/w) mannitol solution. According to Canny's theory, the microwaved and mannitol curves should show cavitation and loss of conductance beginning at approximately −0.3 MPa because in both cases, the turgor pressure would be eliminated or substantially reduced compared to controls. We also tested the refilling capability of nonstressed stems where compensating pressure would be in full operation and compared this with dead stems with no compensating pressure. According to Canny's interpretation of vulnerability curves, the living stems should refill within 5 min. Results failed to support the compensating tissue theory because (a) all vulnerability curves were identical, reaching a −1.5 MPa threshold before substantial loss of conductance occurred, and (b) killed or living stems had equally slow refilling rates showing no significant increase in conductivity after 30 min. In consequence, the cohesion theory remains the most parsimonious explanation of xylem sap ascent in plants.
Genetic diversity of the endangered endemic Agave victoriae‐reginae (Agavaceae) in the Chihuahuan Desert
Authors: Marti´nez‐Palacios Alejandro , Eguiarte Luis E , Furnier Glenn R
Published: April 2006

Long‐lived perennials are a species‐rich, ecologically important component of the North American deserts, yet we know little about their genetic structure, information important for their conservation. Agave victoriae‐reginae is an endemic of the Chihuahuan Desert of northern Mexico that is endangered by collection for the ornamental trade. We examined levels and patterns of variation at ten polymorphic allozyme loci in ten populations representing the range of the species. Levels of genetic variation (mean He= 0.335) and differentiation (mean FST = 0.236) were high. Phenetic clustering suggested the existence of at least three distinct groups of populations. If this pattern of variation is representative of other long‐lived desert perennials, it may explain the species richness of this group and will pose a real challenge to gene conservation efforts.
Phylogeny and evolution of the Betulaceae as inferred from DNA sequences, morphology, and paleobotany
Authors: Chen Zhi‐Duan , Manchester Steven R , Sun Hai‐Ying
Published: April 2006

Phylogeny of the Betulaceae is assessed on the basis of rbcL, ITS, and morphological data. Based upon 26 rbcL sequences representing most “higher” hamamelid families, the Betulaceae are monophyletic, with Casuarinaceae as its sister group, regardless of whether the outgroup is Cunoniaceae, Cercidiphyllaceae, Hamamelidaceae, or Nothofagus. Within the Betulaceae, two sister clades are evident, corresponding to the subfamilies Betuloideae and Coryloideae. However, with only 13 phylogenetically informative sites, the rbcL sequences provide limited intra‐subfamilial resolution. Internal transcribed spacer (ITS) sequences provided 96 phylogenetically informative sites from 491 aligned sites resulting in a single most parsimonious tree of 374 steps (consistency index = 0.791) with two major lineages corresponding to the two traditional subfamilies: Betuloideae (Alnus, Betula) and Coryloideae (Corylus, Ostryopsis, Carpinus, Ostrya). This arrangement is mostly consistent with those from rbcL and morphology and is greatly reinforced by analyses with the three data sets combined. In the Coryloideae, the Ostryopsis–Carpinus–Ostrya clade is well supported, with Corylus as its sister group. The sister‐group relationship between Ostryopsis and the Carpinus–Ostrya clade is well supported by ITS, rbcL, and morphological data. Phylogenetic relationships among the extant genera deduced by these analyses are compatible with inferences from ecological evolution and the extensive fossil record.
Plant genetic diversity in the Canary Islands: a conservation perspective
Authors: Francisco‐Ortega Javier , Santos‐Guerra Arnoldo , Kim Seung‐Chul , Crawford Daniel J.
Published: April 2006

The Canary Islands are an Atlantic volcanic archipelago with a rich flora of ∼570 endemic species. The endemics represent ∼40% of the native flora of the islands, and ∼20% of the endemics are in the E (endangered) category of the International Union for Conservation of Nature. A review of allozyme variation in 69 endemic species belonging to 18 genera and eight families is presented. The average species‐level genetic diversity (HT) at allozyme loci is 0.186, which is twice as high as the mean reported for endemics of Pacific archipelagos. Possible factors contributing to this higher diversity are discussed, but the reasons remain obscure. An average of 28% of the allozyme diversity within species resides among populations, indicating a high level of interpopulational differentiation. Studies of reproductive biology indicate that many of the endemic species are outcrossers. The high total diversity within species, the relatively high differentiation among populations, and the outcrossing breeding systems have implications for species conservation. Decreased population sizes in outcrossing species would promote biparental inbreeding and increase inbreeding depression. The relatively high proportion of allozyme diversity among populations indicates that the most effective strategy for preserving genetic variation in species is to conserve as many populations as possible. The genetic diversity in many Canary Island endemics is endangered by: (1) overgrazing by introduced animals, such as barbary sheep, goats, mouflons, rabbits, and sheep; (2) interspecific hybridization following habitat disturbance or planting of endemics along roadsides or in public gardens; (3) competition with alien plant species; and (4) decline of population size because of urban development and farming.
Cleistogamous capitulum in Centaurea melitensis (Asteraceae): heterochronic origin
Authors: Porras Rafael , Muñoz Jesus M.
Published: April 2006

Cleistogamous capitula formed by Centaurea melitensis display a number of morphological and functional changes with respect to chasmogamous capitula that ensure self‐fertilization. Because no studies have hitherto addressed the evolution of cleistogamy in Asteraceae, it was considered useful to ascertain whether these changes are attributable to one or more of the heterochronic processes reported in the literature. Bivariate allometric analyses were performed, and changes were represented graphically using Gould's clock models for size, shape, and age of several capitulum and floret structures. Results suggest that the partially paedomorphic appearance of cleistogamous with respect to chasmogamous capitula is attributable to three processes: (1) early onset of floral development (predisplacement), (2) decreased growth rate of the whorls studied (except gynoecium width) and (3) early offset time (progenesis). The latter appears to play the most significant role in the origin of the cleistogamous capitulum.
Stamen development in the Ericaceae. I. Anther wall, microsporogenesis, inversion, and appendages
Authors: Hermann Paula M. , Palser Barbara F.
Published: April 2006

Development of the introrse, tetrasporangiate, and normally dorsifixed and poricidal stamens has been studied at the gross morphological and cellular level in ten species of Ericaceae. Microsporogenesis, followed in four species, is normal, with cytokinesis simultaneous, forming tetrahedral tetrads. The tricolp(or)ate pollen is shed as permanent tetrads with each segment two‐celled except in Enkianthus in which pollen grains are three‐celled monads. Anther‐wall development is similar in all four species initially, but no regular pattern of wall development could be recognized thereafter. The tapetum, of parietal origin, is binucleate, glandular, and mainly uniseriate. Viscin threads occur with the tetrads in the three rhododendroid species. A well‐developed endothecium appears only in Enkianthus.

Soon after stamen initiation, anthers of nine species invert at the eventual filament–anther junction to become introrse; in Enkianthus inversion occurs close to anthesis. Microsporogenesis starts during early inversion; greater cell elongation on the abaxial side of the young anther completes inversion by the late sporogenous‐tissue stage. In Erica and, to a lesser extent Calluna, inversion results from greater abaxial than adaxial increase in cell number and length just above the filament‐anther junction. The single vascular strand reflects the degree of inversion. Stamens of six species are appendaged; three have only awns, two only spurs, while one has both. Appendages arise from residual meristems after inversion is completed (or almost so) in all except Enkianthus. Awns develop at what will be the apex at maturity of each anther half. Their length and orientation vary among species. Only in Vaccinium do the awns become hollow (tubules). Spurs, varying in length, shape, and size, arise on the abaxial side from the filament, connective, or thecae.
Pollination ecology of Anthyllis vulneraria subsp. vulgaris (Fabaceae): nectar robbers as pollinators
Authors: Navarro Luis
Published: April 2006

This paper examines the hypothesis that nectar robbing can affect plant reproductive success either positively or negatively. To this end, I investigated various aspects of the pollination ecology of a population of the herb Anthyllis vulneraria subsp. vulgaris in northwest Spain over 5 yr. By observing floral visitors, I found that the most important pollinator species was the long‐tongued bee Anthophora acervorum, which accounted for ∼45% of recorded insect visits. However, just over 45% of visits were by the nectar‐robbing bumble bees Bombus terrestris and B. jonellus. Although the incidence of robbing differed considerably over 5 yr of study, the frequency in every season was very high (66.4–76.5% of robbing) except for 1997 (0% robbing). Despite this high frequency of robbing, robbed flowers had a higher probability of setting fruit than nonrobbed flowers in all years of the study (mean: 82.0 vs. 51.0%; excluding 1997). This increased fruit set in robbed flowers is directly related to bumble bee behavior because the robbers' bodies came into contact with both the anthers and stigmas while robbing. Thus, the robbers effect pollination. These results suggest that the effect of nectar robbers on plant reproductive success is dependent both on the robbers' behavior and on flower/inflorescence structure. The importance of nectar‐robbing bumble bees on the reproductive success of A. vulneraria and its yearly high frequency suggest that the relationship between robbers and this plant is part of a successful long‐term mutualism.
The Military Extraterritorial Jurisdiction Act of 2000: Closing the Gap
Authors: Yost Mark J. , Anderson Douglas S.
Published: April 2006

On November 22, 2000, President Clinton signed into law the Military Extraterritorial Jurisdiction Act of 2000, closing a jurisdictional gap that had concerned the military since the 1950s. The new law establishes federal jurisdiction for crimes committed by civilians who accompany military forces outside the United States, as well as crimes by former members of the military who leave active duty before being prosecuted by courts-martial. Jurisdiction to prosecute under the new statute, however, is granted only to U.S. Article III courts and not to courts-martial.
Rethinking WTO Trade Sanctions
Authors: Charnovitz Steve
Published: April 2006

The most salient feature of dispute settlement in the World Trade Organization (WTO) is the possibility of authorizing a trade sanction against a scofflaw member government. This feature, however, is a mixed blessing. On the one hand, it fortifies WTO rules and promotes respect for them. On the other hand, it drains away the benefits of free trade and provokes “sanction envy.” Undoubtedly, putting teeth in the WTO was one of the key achievements of the Uruguay Round ending in 1994, and a very significant step in the evolution of international economic law.1Yet after six years of experience, WTO observers are questioning whether the availability of trade enforcement is sensible.2This article undertakes an appraisal of trade sanctions as a WTO instrument, and concludes that this practice undermines the trading system. In view of this dysfunction, the article explores alternatives to trade enforcement and points to some softer measures that might have promise.
Memorandum to Congress on the ICC from Current and Past Presidents of the Asil
Authors: Rovine Arthur W.
Published: April 2006

Late last year, in a letter to Congressman Tom DeLay, majority whip of the House of Representatives, twelve former high government officials expressed their support for a bill introduced by Senator Jesse Helms in June 2000, entitled "American Servicemembers' Protection Act."1 The bill, if enacted, would prohibit any agency of the U.S. government from cooperating with the international criminal court (ICC), and proscribe U.S. military assistance to any nation that becomes a party to the treaty of Rome,2 with the exception of NATO members and certain other allied countries.
Afterword: The Question of Linkage
Authors: Bhagwati Jagdish
Published: April 2006

Commenting on the papers in this symposium is paradoxically a difficult task. The authors are remarkably distinguished and one can only learn from what they write. Indeed, I have learned much from them (especially from Dean David Leebron’s splendid clarification of several aspects of linkage, a paper that shows that he should have been an Oxford philosopher if only he had not been such a successful legal scholar). Yet it is easy for an invited commentator to be overwhelmed by despair because the authors write for the most part as if in a research vacuum. There is little attempt at relating what they write to the enormous literature on the problem of linkage.
Response to William G. Wagner's “Law and the State in Boris Mironov's Sotsial´naia istoriia Rossii”
Authors: Mironov Boris N.
Published: April 2006

A forum on Boris Mironov's Russian and English editions of The Social History of Imperial Russia, 1700-1917 (2000) offers the comments of four scholars on different aspects of Mironov's work. David L. Ransel introduces the forum with a consideration of whether Russian and western historical scholarship has been or should be converging, and he reviews the Russian-language response to Mironov's book. William G. Wagner discusses Mironov's key conclusions: that the imperial period was marked by the development of a more individualistic personality, the democratic nuclear family, civil society, and a state order based on the rule of law. He questions, however, the validity of the modernization paradigm as an adequate tool for analyzing these developments. Willard Sunderland comments on the use of the concept of empire in Mironov's book, calling attention to the assertion that imperial Russia was a “normal” European state and that it was not a “true colonial state.” The focus of the book, he argues, remains Russian society within the space of the empire, not the society of the empire as a whole. Steven L. Hoch considers Mironov's chapter on demographic processes, criticizing the use of demographic theory and its application to problems such as fertility and mortality. He also argues that Mironov accepts too uncritically the utility of the statistical data at hand. Boris Mironov responds to Wagnar, Sunderland, and Hoch in turn.
Response to Willard Sunderland's “Empire in Boris Mironov's Sotsial´naia istoriia Rossii”
Authors: Mironov Boris N.
Published: April 2006

A forum on Boris Mironov's Russian and English editions of The Social History of Imperial Russia, 1700-1917 (2000) offers the comments of four scholars on different aspects of Mironov's work. David L. Ransel introduces the forum with a consideration of whether Russian and western historical scholarship has been or should be converging, and he reviews the Russian-language response to Mironov's book. William G. Wagner discusses Mironov's key conclusions: that the imperial period was marked by the development of a more individualistic personality, the democratic nuclear family, civil society, and a state order based on the rule of law. He questions, however, the validity of the modernization paradigm as an adequate tool for analyzing these developments. Willard Sunderland comments on the use of the concept of empire in Mironov's book, calling attention to the assertion that imperial Russia was a “normal” European state and that it was not a “true colonial state.” The focus of the book, he argues, remains Russian society within the space of the empire, not the society of the empire as a whole. Steven L. Hoch considers Mironov's chapter on demographic processes, criticizing the use of demographic theory and its application to problems such as fertility and mortality. He also argues that Mironov accepts too uncritically the utility of the statistical data at hand. Boris Mironov responds to Wagnar, Sunderland, and Hoch in turn.
The Struggle for Proletarian Music: RAPM and the Cultural Revolution
Authors: Nelson Amy
Published: April 2006

Since the 1930s, the zealous, idealistic proponents of musical revolution in Soviet Russia, the Rossiiskaia assotsiatsiia proletarskikh muzykantov (Russian association of proletarian musicians, RAPM), have served primarily as an embarrassing footnote to the history of Soviet music and cultural politics. Scholarly opinion of RAPM is remarkably consistent in its condemnation, as Russian-Soviet scholars and westerners alike dismiss the organization for its "simplistic" (western) or "vulgar" (Soviet) ideology and aesthetics. This consensus suggests that RAPM deserves its place in the dustbin of history alongside the Rossiiskaia assotsiatsiia proletarskikh pisatelei (Russian association of proletarian writers, RAPP) and other militant advocates of cultural revolution. But the condescending (western) and embarrassed (Soviet) dismissal of RAPM is itself simplistic. Seeing members of RAPM as undertalented and unwitting tools of the regime's agenda, or misguided if well-intentioned deviationists, obscures the important role the proletarian musicians played in the evolution of Soviet musical culture and aesthetics.
Without a “Concept”? Race as Discursive Practice
Authors: Lemon Alaina
Published: April 2006

Eric D. Weitz argues that the Soviet Union promoted the development of national institutions and consciousness and explicidy rejected the ideology of race. Yet traces of racial politics crept into Soviet nationalities policies, especially between 1937 and 1953. In the Stalin period particular populations were endowed with immutable traits that every member of the group possessed and that were passed from one generation to the next. Recent scholarship, he suggests, has been resistant to drawing out the racial elements in the Stalinist purges of certain nationalities. Francine Hirsch challenges Weitz’s argument, arguing that the Soviet regime had a developed concept of “race,” but did not practice what contemporaries thought of as “racial politics.” Hirsch argues that while the Nazi regime attempted to enact social change by racial means, the Soviet regime aspired to build socialism dirough die manipulation of mass (national and class) consciousness. She contends that it is imperative to analyze the conceptual categories that both regimes used in order to undertake a true comparative analysis. Weiner proposes that Soviet population politics constandy fluctuated between sociological and biological categorization. Although the Soviets often came close to adapting bioracial principles and practices, at no point did they let human heredity become a defining feature of political schemes. Race in the Soviet world applied mainly to concerns for the health of population groups. Despite the capacity to conduct genocidal campaigns and operate death camps, the Soviets never sought the physical extermination of entire groups nor did they stop celebrating the multiethnicity of tiieir polity. The radicalization of state violence in the postwar era was triggered by die nature and role of the war in the Soviet world, the alleged conduct of those who failed to rise to the occasion, and the endemic unstable and unassimilated borderlands, and not by die genetic makeup of the internal enemies. Alaina Lemon’s contribution suggests that scholars seek racialized concepts by treating discourse as situated practice, rather than by separating discourse from practice. This allows consideration of the ways people use language not only to name categories but also to point to social relationships (such as “race”) with or without explicidy naming them as such. Doing so, however, is admittedly more difficult when die only available evidence of past discursive practices are printed texts or interviews. In conclusion, Weitz responds to these critics.
To Market! To Market! The Polish Peasantry in the Era of the Stolypin Reforms
Authors: Blobaum Robert E.
Published: April 2006

Of the many unexplored aspects of the history of Russian Poland on the eve of the Great War, the condition of peasant agriculture during this time of fundamental social and economic change is one of the more striking. While it has long been acknowledged that the years following the revolution of 1905 “brought excellent conditions for every producer,” that “the advances in agriculture in Congress Poland were considerable,” and that “this progress extended … to the peasants as well,” the role of the Russian state in the development of the Polish countryside, particularly during the period of agrarian reforms associated with P. A. Stolypin, has escaped the attention of historians.
Sexual Transcendence in Tsvetaeva's Poems to Pasternak
Authors: Dinega Alyssa W.
Published: April 2006

Mutuality, do not create impediments for the Castalian stream! Unity in distance: a more intense reality, lying beyond what the eye can see.

In both Marina Tsvetaeva's poetry and her life, sexuality plays an intensely ambiguous role; she vacillates between the belief that the body is merely a “wall” hiding the soul, and the contradictory belief that sexual intimacy is the necessary vehicle to spiritual transcendence. Tsvetaeva's personal sexual adventurousness is by now a well-known fact of her biography; yet this fact is not simply a result of the poet's rebellious nature but is, rather, evidence of a profound philosophical inquiry into the very nature of sex and sexuality that she sustained throughout the course of her life and her writing. Sex is the idiom in which she writes transcendence of her own limiting subjectivity, via an exit into the radical alterity represented by the figure of the beloved.
Dancing with Death and Salvaging Jewish Culture inAusteriaandThe Dybbuk
Authors: Safran Gabriella
Published: April 2006

Jerzy Kawalerowicz told reporters that he made his 1982 film,Austeria(The inn) to commemorate the Polish-Jewish people and culture destroyed in the Holocaust. This non-Jewish Polish director, known best in the west for hisMother Joanna of the Angels(a depiction of death and possession at a medieval French convent), grew up among Jews in the eastern part of Poland. He had been struck by the Polish-Jewish author Julian Stryjkowski's 1966 novella,Austeria,a haunting depiction of Jewish life in Galicia at the beginning of the twentieth century. Kawalerowicz—with Stryjkowski—immediately decided to turn the book into a movie. After the Six-Day War in 1967 sparked an “anti-Zionist campaign” in Poland, however, the Polish government found the Jewish topic of their screenplay “politically unacceptable.” In 1981, the film was granted permission and funding. It was completed in 1982, following the crackdown on Solidarity and the imposition of martial law. The authorities allowed its distribution, having determined that it displayed “humanitarian values” and that it did not represent a political threat. In the capacity of a quasiofficial expression of Polish regret at the passing of the Jews, and perhaps as a demonstration of liberalism aimed at the western critics of the new regime,Austeriawas widely promoted and exported to film festivals abroad.
“The Problem of Political and Social Stability in Urban Russia on the Eve of War and Revolution” Revisited
Authors: Haimson Leopold H.
Published: April 2006

The object of this article is to revisit the themes originally explored in this journal thirty-five years ago in a discussion somewhat misleadingly entitled, “The Problem of Social Stability in Urban Russia, 1905-1917.”’ As older readers of the Slavic Review may recall, this discussion set off heated debates centered on the theses presented in this article about the dual processes of polarization that I distinguished in the dynamics of the political and social crisis in urban Russia even before the outbreak of war: polarization between the industrial workers employed in Russia's urban centers and the well-to-do strata of urban “society,” including those of the professional intelligentsia; and polarization between both the upper and lower strata of Russia's urban centers and the bureaucratic circles that sought to represent the interests and will of the sovereign.
Aesticampianus' Commentary on the De Grammatica of Martianus Capella
Authors: Lutz Cora E.
Published: April 2006

George Saintsbury, on the occasion of the seventy-fifth birthday of the eminent scholar Dr. Frederick J. Furnivall, wrote a poem to pay tribute to his friend's achievements in philology. It begins:

Partes meae sunt quatuor—Dame Grammar saith, saith she,

In Martian of the Goatlings (full quaintly writeth he!)

Litterae, Litteratura, Litteratus, Litterate!
A Second Set of John White Drawings?
Authors: Stern Virginia F.
Published: April 2006

Scadbury Park in Chislehurst, Kent, is the site of the once glorious manor of the Walsingham family, a seat presided over from 1589 to 1630 by Thomas IV, favorite of Queen Elizabeth, cousin of Sir Francis Walsingham, and patron of poets Thomas Watson, Christopher Marlowe, and George Chapman. The original moated manor house is now in ruins, but there is extant among the family papers of Major John Marsham-Townshend, present owner of the Scadbury estate (and through the Betensons a collateral descendant of the Walsinghams), an informative document of 1727 entitled ‘An inventory of the household goods and furniture of the dwelling of the Hon Sr Ed Betenson at Scadbery in Kent, May 26th 1727.’ This manuscript excites speculative interest because of its listing of thirty Indian pictures.