bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulatory Mechanisms of Reproductive Effort in Plants 1. Plasticity in Reproductive Energy Allocation and Propagule Output of Helianthus annuus L. (Compositae) Cultivated at Varying Densities and Nitrogen Levels
Authors: Kawano Shoichi , Nagai Yukio 
Published: February 2005

Abstract Plasticity in growth, reproductive energy allocation (RA), and reproductive output were investigated in Helianthus annuus L. cultivar. Russia (Compositae) grown under varying densities and soil nitrogen levels. The role and behaviour of pollinators in seed production was also examined.Exceedingly marked plastic responses were detected in individual biomass, the patterns of resource allocation to total reproductive structures (RA) and also to propagules, fecundity, reproductive outputs, and propagule size and weight under changing densities and soil nitrogen levels. Plants cultivated at higher densities exhibited proportionately lower individual biomass, lower RA, lower fecundity, lower seed output, and smaller seed size in response to increasing density and decreasing soil nitrogen levels. However, differences due to different N‐levels were not as great as those to changing density.One of the most significant findings was that seed production under limited resource availability, i.e., lack of ample solar radiation and soil nutrients, due to strong interference at higher density plots, is exceedingly costlty, This was most clearly demonstrated by a very sharp increase in relative energy partitioning to a single propagule in response to the increased density and decreasing nitrogen levels, the relative energy cost to a single achcne (RA) increasing from one to twenty‐fourfold. Reproduction was also affected by pollinator‐limitations, and seed size showed a marked position effect.
Dispersal and Settlement Properties of Kandelia candel (Rhizophoraceae) Propagules
Authors: Urasaki Masami , Nehira Kunito , Nakagoshi Nobukazu 
Published: February 2005

Abstract Three different types were found in the floating pattern of Kandelia candel (L.) Druce propagules: horizontal‐floating type, vertical‐floating type and sinking type. These correspond to the specific gravity, which increases with flooding in sea water and the repeated exposure to air. The floating types gradually change to the sinking type. In nature, such a condition is found only under the intertidal zone of shallow lagoons where floating propagules can increase their specific gravity, lie on the mud deposits and develop their roots in contact with the muddy soil. The J‐shaped seedlings frequently found in K. canel populations in mangrove swamps might be recognized as evidence of growing up in the intertidal zone.It is speculated that the horizontal‐floating propagule has a role as a drifter in the ocean and long‐distance disperser, the vertical‐floating one as a colonizer of nearby populations and the sinking one as a successor in the original habitat.
Life History Studies on the Genus Trillium (Liliaceae) I. Reproductive Biology of Four Japanese Species
Authors: Ohara Masashi , Kawano Shoichi 
Published: February 2005

Abstract Four Japanese Trillium (Liliaceae) species which are representative perennial herbs of the temperate deciduous forests—Trillium kamtschaticum (2x), T. apetalon (4x), T. tschonoskii (4x) and T. smallii (6x)—were studied for their reproductive characteristics, e.g., patterns of reproductive resource allocation and reproductive output.In spite of the differences in ploidy levels (from 2x to 6x), all four species showed very similar reproductive traits. It became evident that in response to the increase in reproductive allocation to total reproductive organs (RA), the number of seeds produced per plant (PN) clearly increased. This trend is well in accord with the relationship found in four North American species and also several temperate woodland perennial herbs which occur in closed, stable and predictable environments, and possess typical xenogamous breeding systems. Although there is no conspicuous trend between ploidy levels and PN, one of the significant differences noted in this study was in seed weight, which ranged from 2.93 mg in diploids, to 3.42–3.45 mg in tetraploids, and to 4.47 mg in hexaploids.
A Consideration of the Species Relationships in Subtribe Brassicinae (Cruciferae) in View of Cluster Analysis of Morphological Characters
Authors: Takahata Yoshihito , Hinata Kokichi 
Published: February 2005

Abstract The taxonomic relationships of 53 species (122 strains) in subtribe Brassicinae were studied by using Euclidian distances calculated from 53 metric characters. Through cluster analysis applied to the species and subspecies in the genus Brassica, six large clusters could be defined. By the same method, Diplotaxis was grouped into four clusters, Erucastrum into two, and Sinapis into two. These clusters coincided in general with the taxonomic sections of Schulz (1936), but some exceptions were noted. Most of the exceptional species were those placed in critical positions by cytogenetical observations. It was found that cluster grouping reflected the cytogenetical relations of species fairly well.Relationships among clusters and genera are represented by a Euclidian distance matrix, and the evolutionary trends of those taxa are discussed. Clusters B‐3 (in Brassica), D‐1 (in Diplotaxis) and E‐1 (in Erucastrum) are closely related to each other, forming a complex. This complex is closely related to Sinapidendron. It is postulated that this complex and Sinapidendron might have retained some characters in common with their putative ancestor. Species in the other clusters are considered to be derived from that hypothetical ancestor in the course of evolutionary divergence.
Clonal Variation in the Sprouting Pattern of the Tubers in Eleocharis kuroguwai, a Cyperaceous Weed, with Special Reference to its Perennation Strategy
Authors: Kobayashi Hisao , Tominaga Tohru , Ueki Kunikazu 
Published: February 2005

Abstract Clonal variation in the sprouting pattern of tubers in Eleocharis kuroguwai Ohwi was studied, using 39 clones collected within a longitudinally narrow belt from Wakasa Bay to the Kii Peninsula of Japan and one of “Ohkuroguwai”, a cultivated form.The sprouting pattern of tubers and the relationship between sprouting time and other tuber characteristics varied noticeably among clones. Based on the polygonal graphs of × (mean), x̄ (standard deviation), g1 (skewness) and á (kurtosis) of the sprouting time, the sprouting pattern of 40 clones could be divided into the following three groups. Group A: x̄ and α were small, but g1 and a' were generally great; almost all tubers sprouted early and simultaneously. Group B: x̄ and α were greater, but g1 and a' were smaller than Group A; the majority of tubers sprouted quickly, but the rest of the tubers sprouted gradually. Group C: x̄ and α were very large, g1 was small, but a' showed a comparatively large negative value; all tubers sprouted gradually over a long period.Groups A and B were represented by the irrigation pond group from the Banshu Plain and by the Ohshima Island group in the paddy fields of the southern extremity of the Kii Peninsula. Clones from the paddy field group and from the plain group, both referable to typical rstrategists, exhibited various sprouting patterns of tubers.
Life History Studies on the Genus Trillium (Liliaceae) III. Reproductive Biology of Six Sessile‐flowered Species Occurring in the Southeastern United States with Special Reference to Vegetative Reproduction
Authors: Ohara Masashi , Utech Frederick H. 
Published: February 2005

Abstract Life history characteristics, e.g., stage class structures of natural populations and associated reproductive characteristics, were studied for six sessile‐flowered, diploid Trillium (Liliaceae) species that are restricted to the Coastal Plain region of the southeastern United States.These sessile‐flowered species reproduce primarily by vegetative propagation. Leaf area measurements were used to categorize stage class distributions of natural populations. Populations propagating mainly by vegetative reproduction had non‐sigmoidal, convex‐shaped population structures with most plants being in the intermediate stage classes. Low numbers of individuals in smaller stage classes and an abundance of intermediate sized individuals are due to the fact that vegetative propagules are the primary method for maintenance of local populations.Characteristics associated with sexual reproduction were also examined. Seed output averaged about 20 seeds per plant, except for T. lancifolium which produced 9.7 seeds on the average. Seed setting rates varied between 15.61–44.15% and mean seed weight varied from 4.89 to 10.75 mg. The dominance of vegetative versus sexual reproduction may be due to the fact that all six species occur in ecologically unstable flood plain habitats.
Life History Studies on the Genus Trillium (Liliaceae) IV. Stage Class Structures and Spatial Distribution of Four Japanese Species
Authors: Ohara Masashi , Kawano Shoichi 
Published: February 2005

Abstract The population struaures, spatial and temporal distributions of individual plants, and survivorship were investigated in four Japanese Trillium species (Liliaceae), T. kamtschaticum, T. tschonoskii, T. apetaion and T. smallii.The stage class structures of these four species based on leaf area categories all showed similar depletion curves associated with an increase in stnge class. That is, there occurs a conspicuous decrease in early juvenile stages, subsequent leveling‐off in the intermediate stages and a slight decrease again in the larger stages. The high mortality in juvenile stages was also confirmed by continuous observations in the permanent plots established on the forest floor for T. kamtschaticum and T. apetalon. Furthermore, the analysis of spatial distribution patterns for T. kamtschaticum and T. apetalon revealed successive distributional changes from under‐dispersed (aggregated) to random or overdispersed with the progress of the growth stage.
Sex Change and Population Dynamics in Arisaema (Araceae) I. Arisaema serratum (Thunb.) Schott1)
Authors: Kinoshita Ehchiro 
Published: February 2005

Abstract A projection matrix model was adopted to describe the population dynamics of Arisaema serratum (Thunb.) Schott. This method is most appropriate for describing a complex life history, such as size‐specific determination of sex expression in Arisaema. Size classification was determined from both the life history stage and the pseudostem diameter at ground level, which was transformed into natural logarithms.The calculated population growth rate based on averaged data from 1981 to 1986 was very close to unity. The survival rate was lowest at the seedling stage and gradually increased for larger size classes. But the survival rate was almost the same for the male stage and female stage irrespective of size classes.Individuals in small size classes made greater contributions to the population growth rate (λ) if they were in the asexual stage than in male or female stages. Those individuals in intermediate size classes had greater effects on λ if they were in the male phase and those in large size classes had greater effects on λ if they were in the female stage.
Life History Studies on Arisaema (Araceae) I. Growth and Reproductive Biology of Arisaema urashima Hara1)
Authors: Takasu Hideki 
Published: February 2005

Abstract The growth, reproductive characteristics and energy allocation to reproductive activities were studied in a Japanese species of jack‐in‐the‐pulpit, Arisaema urashima Hara (Araceae). The stage class structures of this species were based on leaflet numbers and leaf area of individual plants in four different populations in Wakayama Prefecture, Honshu, Japan.Populations of A. urashima possess unique male‐biased population structures, with sex ratios (male/female) of 3.14 to 5.00. In this typical sequential hermaphrodite, functionally dioecious species, the switchover from sterile to the male stage or vice versa was found to occur usually in the 11–12 leaflet class, and from a male to female stage or vice versa in the 13–14 leaflet class. However, a large proportion of juvenile plants belonging to the 3–4 to 9–10 leaflet classes, which attained 92.3–98.9% in all four populations, may possibly be recruited by a most vigorous cormlet propagation which occurs every season. Seasonal changes in population structure were also examined for five years, from 1981 to 1985, but population structures remained more or less in the same state, although the sex ratios changed from 3.14 to 6.85.Reproductive allocation (RA) was examined at both the flowering and fruiting stages. The RA to total reproductive structures at the flowering stage showed very conspicuous negative correlations to total biomass for both male (r= ‐0.676, P<0.001) and female plants (r= ‐0.861, P<0.001), whereas the RA at the mature fruiting stage was almost independent of individual biomass. The number of propagules produced per plant (PN) was weakly correlated with the individual biomass (r=0.346, P<0.05). The PN per plant exhibited a conspicuously proportional increase in response to the increase in RA (r=0.860, P<0.001). Ovule number per plant, pollen‐ovule ratios, and fecundity were also examined. In spite of a very high number of ovules borne per plant, ranging from 683 to 1902, and sequential hermaphroditism, the maximum fecundity attained was ca. 60%, with production of 560 to 745 seeds per plant. Larger individuals produced larger and more numerous cormlets, attaining nine per plant.
Distribution of Sexual and Agamospermous Populations of Eupatorium (Compositae) in Asia
Authors: Kawahara Takayuki , Yahara Tetsukazu , Watanabe Kuniaki 
Published: February 2005

Abstract Examinations of chromosome number voucher specimens show that sexual diploid and agamospermous polyploid plants of Eupatorium in Asia can be distinguished by morphology, fertility, and stainability of pollen grains. Using these criteria, reproductive systems (sexual vs. agamospermous) were estimated for 558 herbarium specimens of Eupatorium in East Asia. Of 22 taxa examined, six included both sexual and agamospermous specimens; those of one taxon were all agamospermous; and those of 15 taxa were all sexual. This result shows that 21 taxa are not agamospermous microspecies but are differentiated at the diploid level. Sexual populations of most taxa had restricted geographical distributions. Eupatorium chinense var. chinense and var. oppositifolium consisted of both sexual and agamospermous populations. Sexual populations of these two varieties were allopatric and distinct in external morphology, suggesting differentiation at the species level. The specimens of E. heterophyllum s. str. were all agamospermous, while those of E. mairel, often treated as synonymous with E. heterophyllum, were sexual.In comparing East Asian and North American Eupatorium for the distributional patterns of sexual and agamospermous populations, three differences can be pointed out: (1) Agamospermous plants of autopolyploid origin have evolved in eight species and are widespread in North America; while most agamospermous plants in East Asia may be of allopolyploid origin, have relatively restricted ranges, and are less frequent than the diploid plants with the exception of in E. chinense var. oppositifolium, (2) The number of sexual species with wide range is greater in North America than in East Asia. (3) The number of sexual species with restricted ranges is greater in East Asia than in North America. The results obtained suggest that speciation among the plants of Eupatorium has occurred more recently in East Asia than in North America.
Regulatory Mechanisms of Reproductive Effort in Plants III. Plasticity in Reproductive Energy Allocation and Propagule Output of Two Grass Species, Oryza sativa cv. Akihikari and Coix ma‐yuen Cultivated at Varying Densities and Nitrogen Levels, and the Evolutionary‐Ecological Implications
Authors: Kawano Shoichi , Hayashi Seizo , Arai Hirohito , Yamamoto Masako , Takasu Hideki , Oritani Takashi 
Published: February 2005

Abstract Plasticity in growth, reproductive energy allocation (RA), reproductive output (PN), propagule weight (Pw), fecundity, and relative cost of producing single propagules (RA) and their interlinked properties were critically investigated in two grass species, Oryza sativa L. ev. Akihikari and Coix ma‐yuen Roman., grown under varying densities and soil nitrogen levels.In these two species, exceedingly marked plastic but parallel responses were detected in all significant yield and reproductive traits under changing growing conditions. The results obtained also corresponded very well with those for Coix ma‐yuen, Helianthus annuus and Glycine max reported in our previous works in this series (Kawano and Hayashi, 1977; Kawano and Nagai, 1986; Nagai and Kawano, 1986).In Oryza sativa, plants cultivated at higher densities exhibited proportionately lower individual biomasses, lower seed outputs, and smaller grain size in response to increasing density, although RA remained more or less constant throughout all five different densities, and fecundity showed an abrupt decrease in the overcrowded cohort beyond 400 plants/m2. In this experiment, Coix ma‐yuen was grown only under conditions of extraordinarily overcrowded density (over ca. 4,500 plants/m2) with extremely broad nitrogen fertilizer levels from 20 N (20 kg ammonium sulfate/10 ARE) to 100 N (100 kg/10 ARE). This species likewise demonstrated a remarkably sharp responsive plasticity in significant reproductive parameters with increasing N‐levels, just as was found with changing density (Kawano and Hayashi, 1977).One common significant conclusion obtained from the present series of studies was that sexual propagule production under limited resource availability—for example, a sharp decline in solar radiation and soil nutrients, due to strong interference in higher density plots—is exceedingly costly, implying that there occurs a significant change and variance in this important fitness component under changing environmental conditions. This was most conspicuously demonstrated by a very sharp increase in relative energy partitioning to a single propagule in response to increased density and decreasing nitrogen levels, the relative energy cost to a single seed (RA) increasing from 1.00 to 31.02, and from 1.00 to 10.31 in both paddy field and pot populations of Oryza sativa cv. Akihikari, respectively, and from 1.00 to 4.23 in field populations of Coix ma‐yuen. The adaptive significance of induced changes in several reproductive traits under changing environmental conditions was also discussed in the light of all the evidence available today.
Reproductive Biology of an Amphicarpic Annual, Polygonum thunbergii (Polygonaceae): Spatio‐temporal Changes in Growth, Structure and Reproductive Components of a Population over an Environmental Gradient
Authors: Kawano Shoichi , Hara Toshihiko , Hiratsuka Akira , Matsuo Kazuhito , Hirota Izumi 
Published: February 2005

Abstract The process and mechanisms of spatio‐temporal changes in growth, population structure, as well as various yield and reproductive components of a population of an amphicarpic annual, Polygonum thunbergii (Polygonaceae), with two reproductive systems (aerial chasmogamous flowers and subterranean cleistogamous flowers) along an environmental gradient (light, moisture and soil nitrogen levels) were investigated in the field.The results clearly demonstrate that growth and allocation patterns, population structure, and reproductive output of individuals changed sharply along the environmental gradient in response to seasonal and spatial changes in resource availability. Models predicted that light conditions bring about one‐sided competition, whereas nutrient conditions in the soil engender two‐sided competition. As expected, the degree of one‐sided competition was prominent in the case of a planophile, Polygonum thunbergii. Allocation patterns, seed outputs, individual seed size as well as relative energy costs of chasmogamous and cleistogamous seed as affected by light and nutrient levels were also critically analyzed. The most noteworthy finding was that the size of chasmogamous seeds sharply decreased in response to a decrease in the light regime, while cleistogamous seed size remained constant along the gradient. However, relative cost of both chasmogamous and cleistogamous seeds sharply increased with decrease in the light level, reflecting different degrees of environmental stress, biotic interference, or both.
Reproductive and Pollination Biology of Magnolia and its Allied Genera (Magnoliaceae). I. Floral Volatiles of Several Magnolia and Michelia Species and their Roles in Attracting Insects
Authors: YASUKAWA SHOKO , KATO HIDETOSHI , YAMAOKA RYOHEI , TANAKA HAJIME , ARAI HIROHITO , KAWANO SHOICHI 
Published: February 2005

Abstract Volatile substances emitted from the flowers of eight Magnolia taxa (M. sieboldii ssp. japonica, M. praecocissima var. praecocissima and var. borealis, M. tomentosa, M. salicifolia, M. obovata, M. denudata, and M. grandiflora) and one Michelia species (M. compressa) (Magnoliaceae) were examined and identified using GC‐MS. Volatile substances of these Magnolia and Michelia species consist primarily of monoterpenoids and sesquiterpenoids produced by the mevalonate pathway, acetogenins by the acetate‐malonate pathway, and phenyl‐propanoids by the shikimate pathway. These Magnolia and Michelia species all possessed various combinations of volatile monoterpenoids, acetogenins, and phenylpropanoids, except for Magnolia obovata, which emitted primarily sesquiterpenoids. Free amino acids in pollen of 12 Magnolia and one Liriodendron species were also analyzed, and their value as food sources for pollinators evaluated.Pollinators visiting the flowers of five Magnolia species were collected in their native sites and identified. Their behaviors and roles as pollinating agents were assessed.