bluuebunny/crossref_metadata_2025 huggingface dataset:
Reductions in abscisic acid are linked with viviparous reproduction in mangroves
Authors: Farnsworth Elizabeth J. , Farrant Jill M.
Published: April 2006

We investigate physiological mechanisms behind the convergent evolutionary loss of seed dormancy in plant lineages, focusing on mangroves as a model system. More than 60 angiosperm families, including several mangrove taxa, contain species with seeds that are intolerant of drying and do not undergo dormancy. These desiccation‐intolerant species occur with disproportionate frequency in wet or coastal tropical habitats. In plants, the hormone abscisic acid (ABA) coordinates both the development of desiccation tolerance during the onset of seed dormancy and whole‐organism responses to flooding. Thus, changes in ABA levels and/or modes of action in different plant compartments are implicated in the repeated evolutionary loss of seed dormancy among species of wet habitats. We compare ontogenetic dynamics of ABA levels in embryonic, maternal, and mature vegetative tissue of four phylogenetically independent pairs of related viviparous mangroves and nonviviparous nonmangroves. We demonstrate that ABA levels are consistently lower in embryos of viviparous mangrove taxa than embryos of nonmangrove, nonviviparous sister taxa. In contrast, elevated tissue concentrations of ABA characterize leaves of all mangrove species tested, while ABA levels in maternal tissues vary among mangrove species. These commonalities suggest a functionally important trade‐off between the maintenance of embryonic development and the adjustment of the parent tree to salinity stress. This study yields comparative data on seed physiology in naturally occurring desiccation‐intolerant species, for which these data are currently scarce, and demonstrates a potentially significant role of phytohormones in the evolution of plant life histories.
Life history of the long‐lived gynodioecious cushion plant Silene acaulis (Caryophyllaceae), inferred from size‐based population projection matrices
Authors: Morris William F. , Doak Daniel F.
Published: April 2006

Alpine plants often appear to have long life‐spans as an adaptation to harsh and unpredictable environmental conditions, yet many lack reliable indicators of age that would make it possible to determine their true longevity. Their extended life‐spans also pose problems for measuring lifetime reproductive success, a key component of breeding system evolution in species such as the gynodioecious cushion plant Silene acaulis. For a population of S. acaulis in south‐central Alaska, we applied a recently derived analytical approach using size‐based population projection matrices that allowed us to estimate: (1) the relationship between cushion diameter and age; and (2) lifetime reproductive success through seed production by females relative to hermaphrodites. Because of a combination of slow growth, frequent shrinkage, and extremely high adult survival, we estimate that the largest cushions in our study population exceed 300 yr in age, and some may live substantially longer, despite the seemingly inhospitable alpine environment they inhabit. Females are estimated to produce 4.4 times as many offspring via seed production over the course of their lives as do hermaphrodites, a difference that is more than sufficient to assure the persistence of females despite their inability to transmit genes through pollen. These results highlight the utility of size‐based projection matrices for studying the life histories of herbaceous perennials whose life‐span and lifetime reproductive success cannot be determined easily by any other means.
Lax Midrib1‐O, A systemic, heterochronic mutant of maize
Authors: Schichnes Denise E. , Freeling Michael
Published: April 2006

Lxm1‐O, a dominant EMS (ethyl methanesulfonate) induced mutation in maize (Zea mays, Poaceae), was originally reported to affect the blade/sheath boundary over the midrib region of the leaf. Here we present a more extensive analysis of the Lxm phenotype in nine different inbred lines. Lxm leaves are longer and narrower, and can initiate ectopic leaves. Additionally, Lxm1‐O affects all plant organs observed. Compared to wild‐type siblings, Lxm plants have fewer nodes, basal displacement of reproductive structures, and advance more quickly to the reproductive phase. We address questions as to whether Lxm1‐O abbreviates a specific developmental phase, using hair, wax, and ear node data. We found that each phase was affected, although to varying degrees, depending on the inbred line. We interpret Lxm1‐O to be a heterochronic mutation, causing the developmental acceleration of each phase of the shoot. Lxm1‐O is novel, since other systemic heterochronic maize mutants prolong the juvenile phase, thereby extending shoot development. We discuss the importance of heterochronic mutations in the context of morphological evolution.
Subandrodioecy and male fitness in Sagittaria lancifolia subsp. lancifolia (Alismataceae)
Authors: Muenchow Gayle E.
Published: April 2006

Sagittaria lancifolia subsp. lancifolia is described as cosexual (monoecious), but the study population consisted of 84% cosexuals that typically had 35% pistillate buds and 16% predominant males that typically had 0–2% pistillate buds. Hand‐pollinations showed that pistillate flowers required pollination to set seed, and pollen from both male and cosexual plants was potent. No gender switching was seen in the field or greenhouse. From 24 experimental crosses, 890 offspring were grown to maturity. Among these, all offspring of cosexual sires were cosexual, but approximately half the offspring of male sires were male, implying that maleness was inherited as a single, dominant allele. These results indicate that S. lancifolia is subandrodioecious, a very rare breeding system. It is rare, in part because its maintenance requires a large male‐fitness differential between male and cosexual plants. In the study population, this condition was met by the differential survival of staminate buds on male racemes. Larvae of the weevil Listronotus appendiculatus killed many staminate buds. They did so in a vertical gradient, with buds lower on racemes safer. Male plants have replaced pistillate with staminate buds at these safer positions and thereby enjoy disproportionally higher male fitness.
Sexual reproduction and clonal growth in Reinhardtia gracilis (Palmae), an understory tropical palm
Authors: Mendoza Ana , Franco Miguel
Published: April 2006

Patterns of sexual reproduction and clonal growth were investigated in the understory palm Reinhardtia gracilis var. gracilior over a 3‐yr period. R. gracilis is a very abundant clonal palm in the tropical rain forest of Los Tuxtlas, Veracruz, Mexico. Because ramets form clumps, genets are easily identified in the field. Genets were monitored in a 0.5‐ha area, and classified by size according to the number of ramets they possessed. In contrast to clonal growth, sexual reproduction was highly dependent on genet size. The probability of reproduction, the number of inflorescences, and the number of fruits produced were positively correlated with genet size. However, neither the probability of producing a ramet, nor the number of ramets produced per genet were correlated with genet size. Over the 3 yr of study, 55% of the genet population had at least one ramet with reproductive structures, while <1% (a single genet in one year) had six ramets with flowers. Thirty‐two percent of the mature genets reproduced during each of three consecutive years. In contrast, 58% of the genets produced no new ramets during these 3 yr. No evidence was found of a trade‐off between clonal growth and sexual reproduction. Ramet production increases genet size and this in turn increases genet reproductive performance. Clonal growth in this species may be viewed as a growth strategy that tends to maximize genet fitness.
Mating structure and inbreeding and outbreeding depression in the rare plant Gentianella germanica (Gentianaceae)
Authors: Fischer Markus , Matthies Diethart
Published: April 2006

Isolation and small size of populations as a result of habitat destruction and fragmentation may negatively affect plant fitness through pollinator limitation and increased levels of inbreeding. To increase genetic variation in small populations of rare plants artificial gene flow has been suggested as a management tool. We investigated whether pollinator limitation and inbreeding depression could reduce fitness in Gentianella germanica, an endangered biennial of increasingly fragmented calcareous grasslands in Central Europe. We experimentally excluded pollinators and generated progenies by hand‐pollinating flowers with pollen from different distances. G. germanica was highly selfing. Pollinator exclusion strongly reduced seed set, indicating that pollinator limitation could potentially reduce plant fitness. Germination rate as well as number of leaves and rosette size of progeny from 10‐m crosses was higher than that of progeny from open pollinations, self‐, 1‐m, and interpopulation crosses. After 6 mo of growth differences in the number of surviving plants persisted, whereas differences in plant size did not. The results suggest that inbreeding depression may reduce plant performance in G. germanica. Outbreeding depression in the performance of progeny from interpopulation crosses indicates that caution is necessary in using artificial interpopulation gene flow as a management tool.
Interactions between resources and abiotic conditions control plant performance on subarctic coastal dunes
Authors: Houle Gilles
Published: April 2006

Both abiotic conditions and resource levels affect the performance of plants on coastal dune systems. On the foredune, environmental factors are particularly limiting for plant growth and these vary along a short topographical gradient, from the foot to the ridge. On subarctic coastal dunes in northeastern Canada, this topographical gradient is paralleled by a plant sequence that typically involves Honckenya peploides, Elymus mollis, and Lathyrus japonicus. In this study, field nutrient additions were carried out to evaluate the importance of N and/or P limitation on foredune plant performance. Also, glasshouse experiments were done to determine the significance of interactions between substrate resources (i.e., nutrients and water), and between substrate resources (i.e., nutrients) and an abiotic condition (i.e., salt spray) on the growth of a dune species. Field nutrient additions did not result in any significant increase in plant biomass, although nutrients were accumulated in the rhizomes of all three species present on the foredune and in the aboveground tissues of Elymus. Glasshouse experiments on Elymus showed that nutrient addition could increase plant biomass. However, water availability and salt spray interfered with nutrient use by the plants. I suggest that such interactions between resources and abiotic conditions may significantly affect plant performance and plant sequence on the foredune of coastal dune systems.
Vallisneria americana (Hydrocharitaceae) as a biomonitor of aquatic ecosystems: comparison of cloned genotypes
Authors: Biernacki Maciej , Lovett‐Doust Jon
Published: April 2006

We assessed the effects of local environment on survival, growth, and development in six clones (genotypes) of Vallisneria americana grown at five sites in the Huron‐Erie Corridor. Detrimental effects of local environment on plant performance (rate of clonal growth, leaf and root production, surface area of leaves and roots, plant biomass, rate of flowering, and turion production) were correlated with sediment toxicity and levels of organic contamination determined in independent studies, and differed among plant genotypes. All surviving clones used in the study ranked environmental quality of the five sites in the same order. Two genotypes, which were tolerant of contaminants, survived the 2 yr of exposure at all sites, while other nontolerant clones died within the 1st yr of study, at the two most contaminated sites. The leaf‐to‐root surface area ratio was highly indicative of site quality, and was not affected either by year‐to‐year variation, or by differences between genotypes. The use of cloned plants in this biomonitoring study reduced variance, and increased precision and accuracy of site assessment compared to biomonitoring with genetically variable plants. Clones of V. americana tolerant of contaminants were particularly useful in assessing the most contaminated sites. An approach that uses an array of both tolerant and nontolerant clones is recommended.
Localization of the genes controlling B chromosome transmission rate in maize (Zea mays ssp. mays, Poaceae)
Authors: Chiavarino Amilcar M. , Rosato Marcela , Rosi Pablo , Poggio Lidia , Naranjo Carlos A.
Published: April 2006

In previous papers we found that the frequency of B chromosomes in native races of maize varies considerably in different populations. Moreover, we found genotypes that control high and low transmission rates (TR) of B chromosomes in the Pisingallo race. In the present work crosses were made to determine whether the genes controlling B‐TR are located on the normal chromosome set (As) or on the B chromosomes (Bs). We made female f.0B × male m.2B crosses between and within high (H) and low (L) B‐TR groups. The Bs were transmitted on the male side in all cases. The mean B‐TR from the progeny of f.0B (H) × m.2B (H) and f.0B (H) × m.2B (L) crosses was significantly higher than that from f.0B (L) × m.2B (L) and f.0B (L) × m.2B (H) crosses. The results show that the B‐TR of the crosses corresponds to the H or L B‐TR of the 0B female parents irrespective of the Bs of the male parent. This indicates that B‐TR is genetically controlled by the 0B female parent and that these genes are located on the A chromosomes.
Modeling the growth of individuals in plant populations: local density variation in a strand population of Xanthium strumarium (Asteraceae)
Authors: Weiner Jacob , Kinsman Sharon , Williams Sharon
Published: April 2006

We studied the growth of individual Xanthium strumarium plants growing at four naturally occurring local densities on a beach in Maine: (1) isolated plants, (2) pairs of plants ≤1 cm apart, (3) four plants within 4 cm of each other, and (4) discrete dense clumps of 10–39 plants. A combination of nondestructive measurements every 2 wk and parallel calibration harvests provided very good estimates of the growth in aboveground biomass of over 400 individual plants over 8 wk and afforded the opportunity to fit explicit growth models to 293 of them. There was large individual variation in growth and resultant size within the population and within all densities. Local crowding played a role in determining plant size within the population: there were significant differences in final size between all densities except pairs and quadruples, which were almost identical. Overall, plants growing at higher densities were more variable in growth and final size than plants growing at lower densities, but this was due to increased variation among groups (greater variation in local density and/or greater environmental heterogeneity), not to increased variation within groups. Thus, there was no evidence of size asymmetric competition in this population. The growth of most plants was close to exponential over the study period, but half the plants were slightly better fit by a sigmoidal (logistic) model. The proportion of plants better fit by the logistic model increased with density and with initial plant size. The use of explicit growth models over several growth intervals to describe stand development can provide more biological content and more statistical power than “growth‐size” methods that analyze growth intervals separately.
Cytotype distribution at a diploid–tetraploid contact zone inChamerion(Epilobium)angustifolium(Onagraceae)
Authors: Husband Brian C. , Schemske Douglas W.
Published: April 2006

In North America, the geographic distributions of diploid and tetraploidChamerion(formerlyEpilobium)angustifoliumoverlap in a narrow zone along the southern border of the boreal forest and along the Rocky Mountains. We examined the frequency and distribution of diploid and tetraploid cytotypes in a narrow (5 km) zone of sympatry across an elevational gradient and in putatively uniform diploid and tetraploid reference populations on the Beartooth Pass, in the Rocky Mountains of southern Montana‐northern Wyoming. All five reference populations sampled were dominated by a single cytotype, but only one was completely uniform. In the zone of sympatry, 27 transects were sampled every 2 m for a total of 238 plants. Reproductive status (vegetative, flower buds, open flowers) was recorded, and the ploidy of each plant was determined by flow cytometry. Diploid and tetraploid plants predominated (36 and 55%, respectively) but were heterogeneously distributed among the transects. Six of the 27 transects were fixed for a single cytotype (four transects, diploid; two transects, tetraploid), and in seven others either diploids or tetraploids predominated (frequency >75%). Triploids represented 9% of the total sample and occurred most frequently in transects containing both diploids and tetraploids (G= 3.4, df = 2,P= 0.07). Diploids were more often reproductive (in bud, flower, or fruit) than either triploids or tetraploids (G= 12.0, df = 2,P< 0.001) and were the only cytotype to have produced open flowers. These results suggest that the zone of sympatry is best characterized as a mosaic rather than a cline, with diploid and tetraploids in close proximity and that the distribution of polyploidy is regulated by ecological sorting in a heterogeneous physical environment.
Organellar genetic diversity inPenstemon haydenii(Scrophulariaceae): an endangered plant species
Authors: Caha Carol A. , Lee Donald J. , Stubbendieck James
Published: April 2006

Genetic variation was analyzed in the endangered prairie forbPenstemon haydenii.Individuals from nine populations were surveyed for chloroplast DNA (cpDNA) and mitochondrial DNA (mtDNA) variation. No cpDNA polymorphism was found. Analysis of mtDNA revealed variation within and among populations. A minimum of eight haplotypes were identified. The distribution of these genotypes suggests that there is some correlation between geographic and genetic distances, which reflects the minimal gene flow in this species.
Interspecific variation in plant responses to mycorrhizal colonization in tallgrass prairie
Authors: Wilson Gail W. T. , Hartnett David C.
Published: April 2006

Symbiotic associations between plants and arbuscular mycorrhizal fungi are ubiquitous and ecologically important in many grasslands. Differences in species responses to mycorrhizal colonization can have a significant influence on plant community structure. The growth responses of 36 species of warm‐ and cool‐season tallgrass prairie grasses and 59 tallgrass prairie forbs to arbuscular mycorrhizal (AM) fungal colonization were assessed in greenhouse studies to examine the extent of interspecific variation in host‐plant benefit from the symbiosis and patterns of mycorrhizal dependence among host plant life history (e.g., annual, perennial) and taxonomic (e.g., grass, forb, legume, nonlegume) groups and phenological guilds. There was a strong and significant relationship between phenology of prairie grasses and mycorrhizal responsiveness, however this relationship was less apparent in forbs. Perennial warm‐season C4 grasses and forbs generally benefited significantly from the mycorrhizal symbiosis, whereas biomass production of the cool‐season C3 grasses was not affected. The root systems of the cool‐season grasses were also less highly colonized by the AM fungi, as compared to the warm‐season grasses or forbs. Unlike the native perennials, annuals were generally not responsive to mycorrhizal colonization and were lower in percentage root colonization than the perennial species. Plant growth responsiveness and AM root colonization were positively correlated for the nonleguminous species, with this relationship being strongest for the cool‐season grasses. In contrast, root colonization of prairie legumes showed a significant, but negative, relationship to mycorrhizal growth responsiveness.
The roles of seedling salt tolerance and resprouting in forest zonation on thewest coast of Florida, USA
Authors: Williams Kimberlyn , Meads Michael V. , Sauerbrey Denise A.
Published: April 2006

To determine whether the zonation of seven coastal tree species in north Florida correlated with the relative abilities of their seedlings to tolerate soil salinity, we subjected seedlings of Sabal palmetto, Juniperus virginiana var. silicicola, Quercus virginiana, Celtis laevigata, Ulmus spp., Acer floridanum, and Liquidambar styraciflua to a range of salinities (∼0, 2, 4, 8, 15, and 22 g synthetic sea salt/L; up to 63% full strength seawater salinity) in a 6‐mo greenhouse experiment. Pots with shoot‐killed plants were flushed with freshwater for ≥5 wk to assess recovery. Salt tolerance was assessed as plant survival under saline conditions and as the ability to retain green leaf tissue under saline conditions. Using either criterion, the rank order of seedling salt tolerance correlated significantly (P ≤ 0.05) with that expected based on species zonation near the coast. Agreement was better, however, using retention of leaf tissue as an index of salt tolerance. Species from forest zones that were frequently exposed to tidal water retained green leaf tissue under saline conditions. Species from zones occasionally subjected to very high tides were shoot killed but resprouted following removal of salt from the root zone. Those restricted to zones exposed only to infrequent storm surges died at salinities ≥4 g/L. Thus, differential seedling salt tolerance was consistent with tree zonation and, although the ability of young seedlings to resprout following salt removal did not appear to allow tree establishment at the extreme seaward margin of the forest, it appeared important in intermediate zones.
Cladistic biogeography of Gleditsia (Leguminosae) based on ndhF and rpl16 chloroplast gene sequences
Authors: Schnabel Andrew , Wendel Jonathan F.
Published: April 2006

We used cladistic analysis of chloroplast gene sequences (ndhF and rpl16) to test biogeographic hypotheses in the woody genus Gleditsia. Previous morphological comparisons suggested the presence of two eastern Asian‐eastern North American species pairs among the 13 known species, as well as other intra‐ and inter‐continental disjunctions. Results from phylogenetic analyses, interpreted in light of the amount of sequence divergence observed, led to the following conclusions. First, there is a fundamental division of the genus into three clades, only one of which contains both Asian and North American species. Second, the widespread and polymorphic Asian species, G. japonica, is sister to the two North American species, G. triacanthos and G. aquatica, which themselves are closely related inter se, but are both polymorphic and paraphyletic. Third, the lone South American Gleditsia species, G. amorphoides, forms a clade with two eastern Asian species. Gleditsia thus appears to have only one Asian‐North American disjunction and no intercontinental species pairs. Low sequence divergence between G. amorphoides and its closest Asian relatives implicates long‐distance dispersal in the origin of this unusual disjunction. Sequence divergence between Asian and North American Gleditsia is much lower than between Asian and North American species of its closest relative, Gymnocladus. Estimates of Asian‐North American divergence times for Gymnocladus are in general accordance with fossil data, but estimates for Gleditsia suggest recent divergences that conflict with ages of known North American Gleditsia fossils.
Flower morphometry of Rhizophora mangle (Rhizophoraceae): geographical variation in Mexican populations
Authors: Domínguez César A. , Eguiarte Luis E. , Núñez‐Farfán Juan , Dirzo Rodolfo
Published: April 2006

We explored the patterns of intra‐ and interpopulation variation in flower morphology of the red mangrove, Rhizophora mangle. Twelve populations in Mexico were studied: five from the Gulf of Mexico and the Caribbean Sea, and seven from the Pacific Coast. Six metric floral attributes were measured from a sample of 1370 flowers. Significant differences among populations were found for all six attributes. Because floral attributes were all correlated, scores derived from principal factor analysis were used to describe the variation in flower morphology. Two factors explained essentially all of the variance in flower morphology. Corolla and calyx size had a strong effect on factor 1, while gynoecium size had the higher effect on factor 2. Nested analyses of variance on the scores from both factors revealed significant differences among coasts, among populations within coasts, and among plants within populations. Nonetheless, this variation cannot be explained as a result of clinal variation, as indicated by a series of regression analyses. Cluster analysis (UPGMA) showed that a population from the Pacific coast was clustered together with those of the Atlantic, and the arrangement of populations within each coast showed no evident geographical pattern. We propose that frequent events of extinction and recolonization by a few individuals, followed by selfing, may produce differentiation among populations of red mangrove.
Effect of cross proximity on progeny fitness in a rare and a common species of Eupatorium (Asteraceae)
Authors: Byers Diane L.
Published: April 2006

Offspring from matings between near neighbors may exhibit lower fitness relative to offspring from more distant matings due to spatial structuring of populations resulting from limited dispersal of pollen and seed. This response, which can be interpreted as inbreeding depression, is studied in the rare species, Eupatorium resinosum, and a closely related congener, E. perfoliatum, through the use of hand pollinations representing three distance classes (near‐within a population, far‐within a population, and between populations) and an assay of the offspring in an experimental plot. Early traits such as seed mass and first‐year stem length were not significantly affected by the cross type, although they were affected by maternal parentage. Size and reproduction in the second field season increased with increased pollen donor distance from the maternal plant. Cross type was significant for many traits in the second field season, indicating inbreeding depression in crosses of neighbors (for E. resinosum) and hybrid vigor between populations (both species). This suggests that the rare species, E. resinosum, had a more spatially structured population than E. perfoliatum. The implications of these results for conservation of rare species indicate that protection of habitats sufficient for large populations is necessary to maintain genetic diversity since each population likely consists of many smaller subpopulations.
The effects of seed size, cotyledon reserves, and herbivory on seedling survival and growth in Quercus rugosa and Q. laurina (Fagaceae)
Authors: Bonfil Consuelo
Published: April 2006

In a greenhouse experiment, seedling survival of two oak species (Quercus rugosa and Q. laurina) was greatly affected by the excision of cotyledons 1 mo after germination, with a greater impact on Q. laurina. The effect of seed size was also significant for both species, with a positive correlation between seed mass and survival and growth. The effect of cotyledon excision on seedling growth persisted throughout the first growing season in Q. rugosa and was not analyzed for Q. laurina due to the low number of seedlings that survived cotyledon excision. Seed size significantly affected seedling height, diameter, leaf area, and biomass at 6 mo. Seed size and cotyledon retention affected the ability of Q. rugosa to recover from herbivory, as both factors had a significant effect on relative growth rates after aerial biomass removal. The results show that seedlings originating from large seeds can better endure loss of cotyledons and aerial biomass and thus are better equipped to confront stress early in their lives.
Allopolyploid origin and population genetics of the rare orchid Spiranthes diluvialis
Authors: Arft Anna M. , Ranker Tom A.
Published: April 2006

The process of becoming and the attributes of being polyploid play a major role in the development and maintenance of genetic variation in allopolyploid species. A genetic survey employing protein electrophoresis on 12 populations of S. diluvialis, as well as on populations of eight congeneric species, was conducted to assess the putative allopolyploid origin of S. diluvialis and to determine the genetic variability within and among populations. Genetic identity values indicated S. diluvialis was more similar to S. magnicamporum (0.619) and S. romanzoffiana (0.727) than to any of the other congeneric species assayed. Similar to most allopolyploids, S. diluvialis showed high levels of fixed, or nearly fixed, heterozygosity and a high percentage of polymorphic loci (57.1–71.4%). The mean number of alleles per polymorphic locus in populations of S. diluvialis (2.6–3.3), however, was similar to mean values for both animal‐pollinated, outcrossing, diploid species, and geographically restricted, diploid species (2.6 and 2.5, respectively). Genetic divergence among populations (mean Fst = 0.083) was low, leading to relatively high estimates of interpopulational gene flow (mean Nm = 5.41). Thus, each population harbors most of the genetic variability found within the species. The genetic variation observed within S. diluvialis supports the occurrence of at least two separate hybridization events giving rise to S. diluvialis.
Impact of the flower smut Ustilago cynodontis (Ustilaginaceae) on the performance of the clonal grass Cynodon dactylon (Gramineae)
Authors: García‐Guzmán Graciela , Burdon Jeremy J.
Published: April 2006

Effects of the flower‐infecting smut fungus Ustilago cynodontis on the growth, survival, and competitiveness of the clonal rhizomatous perennial grass Cynodon dactylon were explored through a series of glasshouse experiments. Ustilago cynodontis sterilized C. dactylon by replacing floral structures with a teliospore‐producing fungal stroma. Infection caused a reduction in overall dry matter production and the growth rate of stolons, changed the allocation of resources between roots and shoots, and affected the survival of C. dactylon plants growing in pots under crowded conditions in a naturally lit glasshouse. In mixtures of healthy and infected plants, the growth of infected ones was disproportionally affected. Infection had no effect on the germination or emergence of seedlings. Transmission of the pathogen along stolons was incomplete, especially as the length of the stolon increased. The nutrient status of the soil had no significant effect on stolon growth. Results are discussed in terms of the differential effect of systemic floral smut diseases on tiller‐forming and clonal rhizomatous perennial grasses.
Consequences of incongruency in diurnally varying resources for seedlings of Rumex crispus (Polygonaceae)
Authors: Cavender‐Bares Jeannine M. , Voss Paul B. , Bazzaz Fakhri A.
Published: April 2006

The incongruency of diurnally varying resources essential to plants may detrimentally affect plants early in their development as indicated by reduced water use efficiency and carbon gain. Typical diurnal patterns of light and CO2 availability in a midsized temperate herbaceous or forest gap were simulated in specially designed growth chambers. A sinusoidally varying CO2 treatment (400 ppm minimum, 800 ppm maximum) approximated the diurnal cycle of CO2 at the soil surface, while a steady‐state CO2 treatment (600 ppm) with the same average CO2 concentration provided a control. Crossed with these two CO2 treatments were two light regimes, one with 3 h of high light (850 μmol·m−2·s−1) in the morning (west side of a gap), and the other with 3 h of high light in the afternoon (east side). All treatments received baseline low light (55 μmol·m−2·s−1) for 14 h during the day. Rumex crispus was selected as a model species because of its rosette leaves, which grow close to the ground where diurnal CO2 variation is greatest. The relative timing of diurnal variations in light and CO2 significantly affected seedling water use efficiency, carbon gain, and morphology. Total biomass, photosynthetic rates, daily integrated carbon, water use efficiency, and leaf area were enhanced by morning exposure to high light. Seedlings that were exposed to peak values of light and CO2 incongruently, i.e., those plants receiving intense afternoon light with diurnally varying CO2, were detrimentally affected relative to control plants receiving intense afternoon light with steady‐state CO2. The results of this experiment indicate that the incongruent availability of required resources—such as light and CO2—can detrimentally affect performance relative to when resources are congruent. These contrasting resource regimes can occur on the east and west side of gaps.
A chloroplast DNA phylogeny of lilacs (Syringa, Oleaceae): plastome groups show a strong correlation with crossing groups
Authors: Kim Ki‐Joong , Jansen Robert K.
Published: April 2006

Phylogenetic relationships and genomic compatibility were compared for 60 accessions ofSyringausing chloroplast DNA (cpDNA) and nuclear ribosomal DNA (rDNA) markers. A total of 669 cpDNA variants, 653 of which were potentially phylogenetically informative, was detected using 22 restriction enzymes. Phylogenetic analyses reveal four strongly supported plastome groups that correspond to four genetically incompatible crossing groups. Relationships of the four plastome groups (I(II(III,IV))) correlate well with the infrageneric classification except for ser.SyringaandPinnatifoliae. Group I, which includes subg.Ligustrina, forms a basal lineage withinSyringa. Group II includes ser.SyringaandPinnatifoliaeand the two series have high compatibility and low sequence divergence. Group III consists of three well‐defined species groups of ser.Pubescentes.Group IV comprises all members of ser.Villosaeand has the lowest interspecific cpDNA sequence divergences. Comparison of cpDNA sequence divergence with crossability data indicates that hybrids have not been successfully generated between species with divergence greater than 0.7%. Hybrid barriers are strong among the four major plastome groups, which have sequence divergence estimates ranging from 1.096 to 1.962%. In contrast, fully fertile hybrids occur between species pairs with sequence divergence below 0.4%. Three regions of the plastome have length variants of greater than 100 bp, and these indels identify 12 different plastome types that correlate with phylogenetic trees produced from cpDNA restriction site data. Biparentally inherited nuclear rDNA and maternally inherited cpDNA length variants enable the identification of the specific parentage of several lilac hybrids.
Cybernetics and Marxism-Leninism
Authors: Mikulak Maxim W.
Published: April 2006

In the course of the nineteenth century it became clear that the unfettered speculation obtaining in philosophy frequently could not be useful in science. However, in the Soviet Union it is asserted that natural science can draw its correct "theoretical conclusions" only by relying upon the philosophic and the methodological teachings of dialectical materialism. Certain Soviet Marxists have, on allegedly philosophic grounds, rejected Western genetics, the resonance theory of the chemical bond, the principle of uncertainty of quantum mechanics, relativist cosmology, the relativization of space, time, and matter, probability theory, and symbolic logic. The intriguing question then remains whether Soviet dialectical materialists determine the validity of scientific theories and accomplishments on the basis of a priori judgments derived from philosophic analysis or whether the Soviet attacks on Western scientific thought are, rather, political and ideological in nature.
Communist Rumania and Nonalignment (April 1964—March 1965)
Authors: Ionescu Ghiță
Published: April 2006

In June 1964, when Mr. Patrick Gordon Walker, at that time “shadow” minister on the opposition benches, returned to Britain from a short visit to Rumania, he denned the new policies of the Rumanian Workers Party as “national communism.” This definition is generally accepted. The term, coined some seventeen years ago on the occasion of Titoist Yugoslavia's defiance of Stalinist Russia and serving ever since to describe the policies of any small Communist power in quest of national independence, corresponds almost perfectly to the twin objectives of the Rumanian Workers Party's new policies. As far as “communism” is concerned, its conception is essentially the triple dogma of speedy industrialization, total collectivization, and the full maintenance of the state and the functions of the dictatorship of the proletariat under the monolithic guidance of the party. But as far as the “national” side of the term is concerned, this previously servile party has distinguished itself by the bold and steady way it has progressively affirmed the desire of the Rumanian People's Republic for independence from any individual state or group of powers.
Polish Colonial Ambitions in the Inter-War Period
Authors: Hunczak Taras
Published: April 2006

One of the most interesting political anachronisms of this century was the Polish demand for colonies. The movement developed rapidly in size and intensity in the early 1930s and reached its climax in 1938-39. Ironically, the Poles clamored for colonies at a time when plans were being prepared to turn Poland herself into one of the first colonies of the Third Reich. In pursuing this course of action the Poles fell victim to the spirit of voluntarism, confusing the will to power with the precondition for greatpower status.

The origin of the Polish colonial movement may be dated October 1, 1918, when an organization called Polska Bandera (Polish Flag) was founded by a group of twenty-five men for the purpose of popularizing the importance of the sea to Poland’s national interest and encouraging Polish youth to participate in inland and maritime navigation.
The Old Believers and the New Religion
Authors: Cherniavsky Michael
Published: April 2006

For nearly two hundred years the history of the Raskol, the Russian Church schism of the seventeenth century, was a secret one. To be sure, the Old Believers wrote, and in enormous quantities, but they wrote—by hand—secret manuscripts, copied secretly and circulated secretly. And, except for official condemnations of schismatic teachings and the publication of laws directed against the raskol'niki, more or less serious historical investigation started only in the last years of the reign of Emperor Nicholas I and was confined to printed but highly restricted memoranda passed around in the Ministry of Internal Affairs. Even the nature and the chronology of early Raskol historiography raise questions about the nature of the schism. Why was the history of the Raskol secret for such a long time? Why were the Old Believers persecuted by the government for so long? Was it all, as the government maintained, because they were ignorant, illiterate, superstitious, fanatical, and disobedient toward the Church?
Lenin on Disarmament
Authors: Clemens Walter C.
Published: April 2006

Charges from Peking that Moscow no longer follows the true Leninist position on disarmament are probably among the reasons why Moscow is now publishing new documentary and interpretive material concerning Lenin's views on disarmament and other issues of war and peace. The new materials, coupled with other documents long available, make this an opportune time to review the development of Lenin's views on disarmament and their effect on Soviet policy during his lifetime.
The New Soviet Two-Year Plan
Authors: Thornton Judith
Published: April 2006

For the second time in five years, the Russian planners have abandoned a national plan in mid-course in order to substitute a new program which reflects changed priorities and makes less rigorous demands on the country's economic resources. Although no one has announced the official demise of the Seven-Year Plan, it has been superseded, in fact, by the new Two-Year Plan for 1964-65.

Why has the regime found it necessary to draw up this interim plan to replace the last two years of the Seven-Year Plan? What changes does the new plan make in national economic goals? What are the prospects of the new Two-Year Plan, and what problems are likely to be encountered?
Freedom and Planning in Yugoslavia's Economic System
Authors: Friedmann Wolfgang
Published: April 2006

Following its political break with Stalin's Russia, Yugoslavia has, since the early 1950s, increasingly turned away from the centralized socialist planning that characterizes the Soviet economic system. The main impulse for the gradual elaboration of a distinctive national system came from two directions. First, the Yugoslav conception of federalism was based on the association of six regions (Serbia, Croatia, Slovenia, Bosnia and Hercegovina, Macedonia, Montenegro) with very distinct national, historical, and social traditions and in different stages of economic development. This meant balancing central economic direction with concern for regional needs and interests. Second, the break with Stalinist Russia in 1948 no doubt stimulated a desire to develop, together with political and ideological independence, a distinctive national economic philosophy of communism in contrast to the overcentralized planning bureaucracy of the Soviet Union.
The Making of a Bolshevik: Georgii Chicherin in England 1914–1918
Authors: Debo Richard K.
Published: April 2006

Georgii V. Chicherin's conversion from Menshevism to Bolshevism exemplifies the intense political and ideological stress placed on Russian Social Democrats by World War I. The war split all of Europe's socialist parties, but none so deeply as the already faction-ridden Russian Social Democratic Workers Party. Even after the initial shock had passed and most Russian Social Democrats found their way to one or another of the party's factions, not all members joined a recognizable group. For some the shock was too great, and much time and wandering were needed before they found their bearings. One of these wanderers was Lenin's future Foreign Commissar.
Two Adams and Eve in the Crystal Palace: Dostoevsky, The Bible, and We
Authors: Gregg Richard A.
Published: April 2006

“Prophetic” is a quality which few thoughtful readers would deny Zamiatin's We. For if its moral argument (the irreconcilability of “pure” communism and individual freedom) has, to a disturbing degree, been confirmed by the course of twentieth-century history, so have some of its boldest technological predictions (for example, stateenforced restrictions on human fertility, Communist-inaugurated space travel). Even its genre (an original blend of political satire and science fiction) has proven to be a prophecy of sorts, anticipating, as it does, the more celebrated satirical fantasies of Huxley and Orwell.
Smoler's Idea of Nationality
Authors: Brock Peter
Published: April 2006

“Many Germans make a mistake … in assuming that the idea of nationality is the same with the Slavs as with the Germans, and this false view is responsible for many disagreements, which are very much in the way of a genuine understanding between Germans and Slavs.”

“Our famous patriot and first leader of the new-born nation”—in these words an eminent Lusatian Serb scholar once described the awakener of his people, Jan Ernst (Arnost) Smoler (1816-84).
The Election of Archbishop Stablewski
Authors: Rosenthal Harry Kenneth
Published: April 2006

The selection of a successor to Archbishop Dinder of the Poseń-Gnesen (Poznań-Gniezno) archdiocese resulted in one of the more interesting episodes in German-Polish relations. Coming as it did, just after the fall of the Iron Chancellor, the process of selection revealed with the utmost clarity the perceptions and priorities of the participating Germans and Poles.

The history of the Posen-Gnesen archbishopric gave significance to the question, for in the German Empire, as both German and Pole knew, only the Posen-Gnesen archdiocese had customarily had a Polish archbishop. This churchman tended to be the Polish community's most prominent spokesman and its visible head. He symbolized a unique and worthy tradition. In his person, until 1886, Polonia lived. Then, in that year, the Vatican and Bismarck dealt a severe blow to the Polish community by agreeing on the German Dinder to succeed the Pole Ledóchowski who had been forced to surrender his position.
Das Kapital Comes to Russia
Authors: Resis Albert
Published: April 2006

Pro captu lectoris habent sua fata libelli.

TERENTIANUS MAURUS

The triumph of Marxism in backward Russia is commonly regarded as a historical anomaly. Yet, some forty-five years before the Bolshevik Revolution, Marx's Das Kapital in Russian translation had already won quick acclaim. Indeed, the book for a brief time enjoyed greater renown in Russia than in any other country, and it won a warm reception—for highly varied reasons— in many political quarters. Although valuable studies have been written on the first responses to Marxism in Russia, little note has been taken of the rapid and widespread success the book scored, and the reasons for this success have received even less attention. An exploration of these reasons will therefore cover a rarely traveled byway of Russian intellectual history.
Legislative Authority in the Soviet Political System
Authors: Richard Little D.
Published: April 2006

It is a settled principle of Soviet constitutional law that the USSR Supreme Soviet is the supreme representative organ, the supreme legislative body, and the supreme executor of the people's sovereignty. The 1936 Constitution subordinates all other organs of government to the Supreme Soviet, and it alone, on the national level, has the right to form governments, pass laws, and amend the Constitution. The Constitution also stipulates, however, that the Communist Party of the Soviet Union is “the vanguard of the workers in their struggle for the construction of a communist society and constitutes the guiding core of all workers’ organizations, public as well as governmental.”
Dobroliubov's Critique of Oblomov: Polemics and Psychology
Authors: Kuhn Alfred
Published: April 2006

N. A. Dobroliubov's critical essays on Goncharov, Turgenev, Ostrovsky, and Dostoevsky, written in the brief period of two years preceding his death in 1861, established a reputation and influence second only to Belinsky's in the history of Russian literary criticism. Of these essays “What Is Oblomovism?” holds particular interest. Published in the May 1859 issue of Nekrasov's Sovremennik (The Contemporary), it was Dobroliubov's first major review and possibly his best. It is a central document in the history of the conflict between the liberals of the 1840s and the radicals of the 1860s, or, in the phrasing of Turgenev's title, between “fathers and sons.”
Laying a Legend to Rest: The Poet Kapnist and Ukraino-German Intrigue
Authors: Edgerton William B.
Published: April 2006

For seventy-five years a furiously controversial legend has hung over the name and reputation of the eighteenth-century Russian poet Vasilii Vasilievich Kapnist. It began at a meeting of the Polish Historical Association on December 7, 1895, when Professor Bronislaw Dembiński, of the University of Lwów, read a report about his discovery of a document in the Preussisches Geheimes Staatsarchiv stating that a Ukrainian gentleman named Kapnist had secretly gone to Berlin in April 1791 and talked with the Prussian minister of state, Count Ewald-Friedrich Hertzberg, about the Ukrainians’ desire to get Prussian help in freeing themselves from Russia. Professor Dembinski's paper, published in 1896, was promptly brought to the attention of Ukrainian readers by the Ukrainian historian M. S. Hrushevsky, who expressed the opinion that the Kapnist who secretly visited Berlin was “undoubtedly none other than the well-known author of Chicanery [Kapnist's comedy Iabeda].“