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1.
Shoichi Kawano 《Journal of plant research》1981,94(3):285-294
Several reproductive triats in plants were studied in more than 200 populations of 61 wild species from diverse ecological
conditions. As a result, it was found that there occur three distinct types of plants in the energy allocation patterns to
reproductive structures (RA) and the propagule output per plant (PN), i.e. (1) the number of propagules per plant increases in response to the increase in RA (Type I), (2) the number of propagules
decreases in response to the increase in RA (Type II), and (3) the RA remains constant despite the great differences in the
propagule number per plant. A conspicuous trade-off relationship was also discovered to occur between the RA to a single propagule
(RA) and the propagule output per plant (PN), such that log RA=logC−blot PN, or RA=C/PN
b
=CPN
−b
, where C is a constant. The three different ranges ofb-values were recognized, i.e.b<1.0,b>1.0, andb=1.0, which correspond to Type I, Type II, and Type III, respectively. Related problems to the concept ofr- andK-strategy are also discussed. 相似文献
2.
Toshiyuki Sato 《Journal of plant research》1984,97(1):1-12
To understand the life history characteristic for expanding the distributional area to colder climates, developmental age
structure of population ofCyrtomium falcatum was observed along southwestern coasts of Hokkaido at the natural northern boundary of its distribution, with reference to
the alternation of generations. The length and number of pinna of fertile leaves ofCyrtomium falcatum decrease towards the northern part of Japan. In southwestern Hokkaido, typically dwarf fertile leaves and gametophytes were
observed growing together on cliffs nearby the sea. To estimate the developmental ages of small and dwarf leaves, the number
of venation (NV: branching number of vein from midrib) of leaves was counted on each sporophyte. The sporophyte with leaves
at the simple pinna stage ranging from 0–25NV, is predominant in the population of southwestern coasts of Hokkaido. The fertility
of the sporophyte seems to be achieved more than five years after the germination. The gametophytes were also observed at
the location to be almost equal in number to sporophytes. The number of gametophytes and sporophytes decreases with advancement
of developmental stages. In the same location at Okushiri Isl. with slight gradiency of humidity, the gametophyte is predominant
on the drier cliff, while the sporophyte is predominant on the humid hole. The population ofCyrtomium falcatum at the natural northern boundary in Hokkaido, seems to have the life history characteristic with alternation of generations.
Contribution No. 2557 from the Inst. of Low Temp. Sci. 相似文献
3.
After the further studies on the open dichotomous leaf venation ofKingdonia andCircaeaster, we considered that the venation of these genera is incomparable to that of some gymnosperms such as Ginkgoaceae, and is
a degenerated characteristic in the morphological nature. We also considered that this characteristic is very important on
determining the systematic relationship between these genera and other members of Ranunculales (sensu Takhtajan 1980), but
its implication in the phylogeny of angiosperms was overemphasized.
The project was supported by The National Natural Science Foundation of China (No. 39630030) and The Laboratory of Systematic
& Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences. 相似文献
4.
Toshiyuki Sato 《Journal of plant research》1985,98(2):99-111
The temperate fernsPolystichum craspedosorum, P. retroso-paleaceum, P. tripteron, P. braunii andP. microchlamys are distributed widely in Hokkaido: on 13 Hokkaido mountains their average altitudinal distributions are 450, 479, 570, 689
and 964 m above sea level, respectively. The developmental stage of the sporophytic leaf is expressed by the “number of venation”
(NV, the number of veins branching from the midrib of the leaf), which, inPolystichum ferns, is itself a qualitative expression of the phase-change from sterile to fertile leaf production and is more discriminatory
than leaf area, length or dry weight. Usually, the developmental stage structure of the fertile leaf expressed by NV in the
fivePolystichum ferns showed a normal distribution. Among the fourPolystichum ferns that grow in the forest understory of Hokkaido's cool temperate regions, a good correlation was found between the mean
altitude of vertical distribution and the maximum NV of the leaf (r=−0.993) and the initiation of maturity in the relative
developmental stage (r=0.991) of the ferns.Polystichum craspedosorum found on cliffs, however, matures at much earlier stage and has the smallest maximum NV. In the developmental stage expressed
by the NV, the initiation of fertility and maximum NV seem to be correlated with altitudinal distribution and habitat in populations
ofPolystichum ferns in Hokkaido.
Contribution No. 2694 from the Inst. of Low Temp. Sci., Hokkaido University. 相似文献
5.
Summary Histochemical reactions indicating keratinization have previously been demonstrated in parts of the epidermis of Bagarius bagarius. Fluorescence histochemistry and electron microscopy have now confirmed these results. Elevated areas of the epidermis are capped by a layer of dead cells with altered contents. On the outer aspect of these cells a dense layer, 18 nm thick, beneath the plasma membrane corresponds to the resistant envelope found in keratinized cells in tetrapod vertebrates. In Bagarius this layer does not extend to all faces of the keratinized cells, but a similar envelope has been detected in two other sites of piscine keratinized epidermis investigated, namely in the breeding tubercles of Phoxinus phoxinus and in the teeth of Lampetra fluviatilis. In the elevated areas of Bagarius-epidermis, the epithelial cells undergo progressive changes in cytoplasmic organization as they become more superficial. The second tier from the surface is sealed by tight junctions and is separated from the overlying keratinized cells by a sub-corneal space resembling that found in keratinized amphibian epidermis. Histochemical evidence of a high lipid content in the outer layers of the epidermis correlates with the presence of lipid inclusions and lamellated membranous profiles in the material studied by electron microscopy. Histochemical results show that the fin skin of Blennius pholis is not keratinized, but secretes a cuticle, histochemically reactive for both proteins and glycoproteins. 相似文献
6.
All genera ofAnnonaceae endemic in Australia (Ancana, Fitzalania, Haplostichanthus) show almost exactly the same type of disulcate (disulculate) pollen with intact exine extending over the sulci. Tetrad stages inHaplostichanthus andAncana reveal a latudinal subequatiorial orientation of the two sulci at the proximal hemisphere. Sometimes they fuse into a ±zonosulcate aperture.Fissistigma pollen grains are ±globose and have a flattened pole with a central elevation and a concentric groove, covered by a somewhat reduced exine. This palynological characters give further support for separating the generaAncana andFissistigma. Germination was observed inHaplostichanthus where the pollen tube emerges at one of the two sulci and inFissistigma where the flattened part breaks up during germination. The aperture types described here are obviously transitional stages between aperturate and inaperturate pollen grains and are discussed in regard to pollen evolution. 相似文献
7.
Fungal associations of Danish Calluna vulgaris roots with special reference to ericoid mycorrhiza 总被引:1,自引:0,他引:1
Fungi were isolated from young, serial-washed roots of Calluna sampled from a Danish heathland, Hjelm Hede. Of the 626 isolates, those that were dark, sterile and septate were divided into 13 morphological groups based on their appearance in culture on malt agar. Mycorrhizal synthesis in vitro showed that several groups formed typical ericoid mycorrhiza with seedlings of Calluna; these ericoid mycorrhizal fungi were morphologically similar to Hymenoscyphus ericae. The identities of the other dark, septate fungi are uncertain. Oidiodendron spp. were isolated in a very low frequency; these fungi also formed typical ericoid mycorrhiza. The Calluna root system on Hjelm Hede demonstrated a high morphological diversity among the associated dark, septate fungi suggesting that more than one fungus could coexist in the same host root system. 相似文献
8.
Life histories of two populations of Tanymastix stagnalisfrom sites in central Italy, differing in climate and altitude above sea level, were compared to obtain information on the tolerance limits of this species.Temperature was the main factor affecting the biology of Tanymastix stagnalis. Significant differences in growth patterns occurred at different sites. A colder climate induced delayed hatching, slower differentiation and maturation, but a longer life span in the mountain population (Forca Canapine) than in the plain (Fosso dei Mergani).Both populations exhibited an initial fluctuating sex ratio, which later became female biased, a pattern which could be the consequence of adaptation to the unstable nature of the biotopes studied. 相似文献
9.
A flattened discoid flagellate collected from the Seto Inland Sea, Japan, has been examined by light and electron microscopy.
This alga agrees well withClisthodiscus luteus Carter. It has two heterodynamic flagella emerging from a furrow on the upward side of the cell that contains six to 13 yellow-green
parietal chloroplasts. It does not rotate but smoothly glide while swimming. The cell has a thin periplast lying between the
plasmalemma and chloroplasts. Neither lipid bodies nor mucocysts are seen in the periplast. The pyrenoid matrix being free
from thylakoids is penetrated by several cytoplasmic canals from various directions. There are no vesicles of periplastidal
network in the narrow space between chloroplast envelope and chloroplast ER.
The ultrastructural features ofO. luteus are unique, sharing certain characters with the raphidophycean algae but others withPseudopedinella pyriformis, a unique member of the Chrysophyceae. 相似文献
10.
Brown spot disease ofRheum officinale, a traditional medicinal plant in South East Asia, was newly recorded from the highland area of West Java Province. After
confirmation of its pathogenicity towardRheum officinale and comparison of its morphology with hitherto known species, the casual fungus was identified asAscochyta rhei. It produces widely varied conidia from unicellular and bacillar conidia (Phoma-type), 1-septate oblong conidia (Ascochyta-type) to 2–3-septate cylindric conidia. These conidia were sometimes formed within the same pycnidium. They could germinate
easily and produce the similar colonies to each other.
Supported by “Joint Study Project for Strengthening Research on Diseases of Industrial Crops in Indonesia, Japan International
Cooperation Agency (JICA)” in BALITTRO. 相似文献
11.
Tatjana V. Shulkina 《Plant Systematics and Evolution》1980,136(3-4):233-246
The biomorphological radiation of theCampanulaceae is outlined. Certain aspects of ontogeny and life-form are specific and constant for the tribes and genera of the family, and for the sections, subsections and series ofCampanula. Therefore, a certain correlation exists between the biomorphological characters and the reproductive structures underlying the taxonomic system. 相似文献
12.
Dr. M. C. Thorndyke 《Cell and tissue research》1977,184(4):539-550
Summary Transmission electron microscopy shows the gastric epithelium of Styela clava to comprise at least three distinct cell types. Ciliated mucous cells which form the crest of each stomach ridge produce mucus by an unexpected route. Vacuolated cells lining the ridge sides appear to be absorptive in function. Gastric enzymes are produced by typical protein secreting cells scattered amongst the vacuolated cells. Undifferentiated cells are found in the crypts between ridges. The structure and function of the gastric epithelium in Styela is discussed with special reference to the wider concepts of ascidian gut organization.The author is grateful to Mrs. L. Rolph for technical help with scanning electron microscopy and Mr. J. Calvert and Mr. R. Jones for assistance with the transmission electron microscopy. Animals were collected through the kind offices of Mr. J. Sturges and other staff of the Admiralty Marine Trials Station, Portsmouth. This research was carried out during the tenure of SRC grant No. B/RG 82919 -The localization of polypeptide hormones in the pharynx and gut of Protochordates 相似文献
13.
Summary One of the pupal cuticle protein (PCP) genes has been found within an intron of aDrosophila housekeeping gene (theGart locus) that encodes three enzymes involved in the purine pathway. This intronic gene has been described as a gene within
a gene, and the gene is now called a “nested” gene. Because the intronic PCP gene has sequence similarity with the larval
cuticle protein (LCP) gene, it may have been derived from one of the LCP genes or their ancestral gene. We have studied possible
phylogenetic relationships among these five genes by comparing nucleotide sequences of four LCP genes with that of the PCP
gene. The results obtained suggest that the PCP gene may have originated from an ancestral gene before duplication of the
LCP genes occurred. Using the number of synonymous (silent) substitutions, we then estimated the divergence time between the
PCP gene and the LCP genes to be about 70 million years (Myr). The divergence time estimated is much larger than that for
the sibling species ofD. melanogaster (about 2.5 Myr), indicating that the “nested” gene structure can be seen not only inDrosophila melanogaster, but also in other distantly relatedDrosophila species. 相似文献
14.
Urs Schmidt-Ott Klaus Sander Gerhard Martin Technau 《Development genes and evolution》1994,203(6):298-303
The engrailed expression in embryos of a beetle, four midges and a fly has been analysed with special reference to the terminal regions. In all six species the segmental expression pattern is very similar but variability occurs in the clypeolabrum, foregut and hindgut. In some cases, segmental engrailed expression seems to be extended into the hind- and/or foregut. The engrailed expression of these species is compared with published data from other insects.
Correspondence to: U. Schmidt-Ott 相似文献
15.
Recent literature on peatland restorationindicates as a general goal repairing orrebuilding ecosystems by restoringecosystem structure, trophic organization,biodiversity, and functions to thosecharacteristic of the type of peatland towhich the damaged ecosystem belonged, or atleast to an earlier successional stage.Attainment requires provision of anappropriate hydrological regime,manipulating surface topography, improvingmicroclimate, adding appropriate diaspores,manipulating base status where necessary,fertilizing in some cases, excludinginappropriate invaders, adaptively managingthrough at least one flood/drought cycle toensure sustainability, and monitoring on ascale of decades. Several matchingconditions favoring or opposing restorationare suggested.In the restoration of peatlands, successeshave generally been those of short-termrepair. Periods of restoration have beenmuch too short to ensure progression to, oreven well toward, a fully functionalpeatland reasonably compatible with thepristine state of similar peatlandselsewhere, although with altered surfacepatterns.Long-term monitoring ofpeatland-restoration projects is essentialfor a better understanding of how to carryout such restoration successfully.Paleoecology is suggested as anunderutilized tool in peatlandrestoration. 相似文献
16.
M. Oléo J. P. C. Van Geyt W. Lange Th. S. M. De Bock 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1986,73(2):261-266
Summary A tetraploid (2n=36) interspecific hybrid was obtained involving three species belonging to three different sections of Beta. The hybrid was highly sterile and did not show apomixis. At meiosis, up to nine bivalents were observed, most probably resulting from autosyndesis of the chromosomes of Beta lomatogona. For nine isozyme systems, individual enzyme expression was investigated in the parental species and in the hybrids. No silencing of genes or genomes was observed. In the case of some polymeric enzymes interspecific heteropolymers could be detected. 相似文献
17.
Tsukaya H Tsujino R Ikeuchi M Isshiki Y Kono M Takeuchi T Araki T 《Journal of plant research》2007,120(3):351-358
We analyzed leaf shape variations in Ainsliaea apiculata Sch. Bip. to evaluate the uniqueness of morphological characters in populations on Yakushima Island, Kagoshima Prefecture,
Japan. Leaf size and shape from populations on Yakushima Island (n = 300) were compared with those from populations in other areas of Japan (n = 300). A considerable amount of variation occurred in leaf size in A. apiculata populations both on Yakushima Island and elsewhere, but clear discontinuities in leaf size were not detected. Some variants
previously thought to be endemic to Yakushima Island, i.e., A. apiculata var. acerifolia and A. apiculata var. rotundifolia, were also found in other locations in Japan. Moreover, these leaf types were found to be continuous with the typical leaf
shape of A. apiculata var. apiculata via various intermediate types, suggesting the need for future revision of these taxa. Based on these results, we reevaluated
the uniqueness of the Yakushima populations of A. apiculata in terms of leaf variation. The uniqueness of the Yakushima populations was defined by a more diverse leaf shape than found
in populations from other areas. 相似文献
18.
Between 1998 and 2000 soil samples from 82fields in north, east, central and south westof Switzerland were analysed for presence ofinsect pathogenic soil fungi using a selectivemedium and the Galleria bait method. Thedetection rates with either method were verysimilar. 96% of the fields distributed overall examined regions contained Metarhiziumanisopliae. The presence of Beauveriabrongniartii was limited to sites colonised byits host, Melolontha melolontha. It wasalso present at a site where M.melolontha disappeared about 40 years ago. Onthe other hand, B. brongniartii was notfound in four fields containing M.melolontha populations. Beauveriabassiana, Paecilomyces fumosoroseus and Conidiobolus sp. were other entomopathogenicfungi isolated during this survey. Differencesin the presence of M. anisopliae betweenarable fields and adjacent meadows as well asbetween orchards and meadows are discussed. 相似文献
19.
Taxonomic treatment of the achlorophyllous monotropoid plant Monotropastrum humile is still unclear and confusing because of the lack of detailed morphological analyses and molecular phylogeny. In particular,
the taxonomic status of a glabrous variety, M. humile var. glaberrimum, is under debate. Our detailed examination of the morphological characteristics of living plants revealed that M. humile var. glaberrimum can be easily distinguished from the putative conspecific taxon M. humile var. humile by characteristics not previously recognized, namely the shape and color of the floral disc. Most morphological features
characterizing Cheilotheca were also found in M. humile var. glaberrimum. Moreover, there was considerable nucleotide differentiation in the internal transcribed spacer (ITS)2 sequences of M. humile var. humile and var. glaberrimum. Molecular analysis of the phylogenetic relationship of M. humile var. humile, var. glaberrimum, and other monotropoids using ITS2 sequences showed that two varieties of M. humile formed a monophyletic clade with a member of a different genus, Monotropa L., but obvious phylogenetic relationships among these three taxa were not obtained. Thus we conclude that Monotropastrum humile var. glaberrimum should be treated as a distinct species. However, the generic affiliation of M. humile var. glaberrimum could not be determined because of its intermediate character state combination and the insufficient characterization of
related species. We strongly suggest that Monotropastrum as a whole needs re-evaluation. 相似文献
20.
L. De Meester 《Hydrobiologia》1995,307(1-3):167-175
In an analysis of a life table experiment involving positively, intermediately and negatively phototactic Daphnia magna clones, life history traits such as the average duration of the adult instar, neonate and adult body size were found to be correlated with phototactic behaviour. The size of the eggs and neonates was positively correlated with adult body size, and with egg development time. Adult body size was positively correlated with the size of the second and subsequent clutches. I argue that the intrinsic positive correlation between offspring size and egg development time is a key factor structuring the differences in life history patterns observed between the positively and intermediately phototactic Daphnia genotypes, and that the two life history patterns are to be considered alternatives suited for different environmental conditions (e.g. habitats with and without strong predation pressure on adults). 相似文献