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1.
Haploid sporophytes of Osmunda claytoniana (2n = x = 22) were apogamously produced from calli when cultivated on a hormone-free medium. Flow cytometric analysis showed that
ploidy chimeras were spontaneously produced in a haploid sporophyte of O. claytoniana and those of O. japonica that were obtained in the previous study. In the haploid sporophyte of O. claytoniana, a diploid pinnule and a partially diploid terminal segment were produced in a haploid pinna. In O. japonica, a haploid sporophyte yielded a diploid pinna in a haploid frond, and another haploid sporophyte yielded a diploid pinnule
in a haploid pinna. Diploid chimeras were large in size and could be readily distinguished from other haploid parts of the
fronds. It is likely that the chimeras were produced clonally from a single diploid cell that established chromosome doubling. 相似文献
2.
A. L. Allcock J. M. Strugnell P. Prodöhl U. Piatkowski M. Vecchione 《Polar Biology》2007,30(7):883-893
During recent cruises aboard RV Polarstern in the Antarctic Peninsula region, a new species of benthic octopodid was discovered whose generic affinities based on morphological
characteristics were uncertain. Molecular sequence analysis of six mitochondrial and nuclear genes allows this species to
be placed with confidence within the genus Pareledone. The species is described herein and morphological diagnostic characters are provided for its identification. 相似文献
3.
Based on 100 species representative of the four genera, we scored 290 herbarium specimens for a number of morphological characters. The data were subjected to canonical discriminant analysis using characters different from those in the identification key to these genera byBaum, Yen, andYang (1991). These characters collectively support the four groupsAgropyron, Kengyilia, Roegneria, andElymus as previously defined. The four groups are also supported by the linear discriminant function with an overall rate of 83% correct classification. Length of lemma awn was found to be an additional diagnostic character asAgropyron andKengyilia have lemma awns shorter than 5 mm, whereasRoegneria andElymus have longer lemma awns with very few exceptions. Length of glume awns is also a useful supplementary generic diagnostic.Agropyron andElymus have glume awns, whereas the majority of species ofKengyilia and more than half of the species ofRoegneria lack them. If a glume awn is present it is usually not longer than 1 mm. 相似文献
4.
We studied the short-term impact of sediment load on the photosynthetic performance of Saccharina latissima sporophytes exposed to ultraviolet radiation (UVR). The algae were collected from different sediment-influenced environments
in Svalbard in August 2007. Initial optimum quantum yield (F
v/F
m) of sediment-covered sporophytes was significantly higher compared to sediment-free sporophytes. Experimental sediment coating
on blade discs had a photoprotective function by screening out 92% of the weighted UV-B (UVery) treatment. No UVR-induced photoinhibition was observed in sediment-coated blade discs while sediment removal caused a reduction
in F
v/F
m not only after 12-h UVR exposure but also after 6-h recovery in low white light compared to the initial value. Thus, sediment
coating has a short-term functional significance in mitigating the negative effect of UVR on photosynthesis of an important
kelp species and set a baseline for further studies.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
5.
The purpose of this paper is to produce a classification of theHordeum murinum complex. Using an experimental design to account for the environmental component of the phenotypic variation, material from sources throughout the old-world range ofH. murinum was grown in a common environment. Eight morphological characters were measured on the resulting triplets (i.e., the central and lateral florets, glumes and rachis internode). Clustering, variance and discriminants analyses of these data suggest that there are three distinct groups. This classification is then examined for consistency with hypotheses obtained from the work of other researchers and discussed in light of the known biology of the plants. An identification key to members of the complex using the triplet characters is provided. 相似文献
6.
Developmental leaf architecture was quantitatively described in terms of measurements of various parameters on leaf blade
from different size of sporophytes inDryopteris monticola, D. tokyoensis and a putative hybrid,D. kominatoensis in the natural site of Hokkaido, to compare the ontogenetic differentiation in foliage structure among allied ferns. The
morphological stage of leaf and sporophyte was tentatively quantified by the number of midrib branches of the leaf (NV, number
of veins), which exhibited a significant correlation to the leaf-shape complexity from a circle (DI=marginal length/2×(3.14×square)1/2) of leaf blade.
D. kominatoensis showed intermediate values between others in following characters; DI increase, maximum NV (also blade length), maximum number
of costa branches of pinnae (NVMP), number of costa branches of the lowest pinna (NVLP), difference between NVMP and NVLP
(NVMP-NVLP), during heteroblastic leaf development. A larger number of leaves per sporophyte was found inD. kominatoensis than in others. The fertility rate (%) and initiation of fertility (IF) in the relative developmental stage (RDS) ofD. kominatoensis shifted to that ofD. tokyoensis, while the order of pinnae with NVMP shifted to that ofD. monticola. Even in the intermediate characters inD. kominatoensis, slight shifts in characters to those of putative parents were found during heteroblastic leaf development.
Contribution No. 3145 from the Institute of Low Temperature Science, Hokkaido University. 相似文献
7.
The internal transcribed spacer (ITS) region (ITS1, 5.8S rDNA, ITS2) represents the most widely applied nuclear marker in
eukaryotic phylogenetics. Although this region has been assumed to evolve in concert, the number of investigations revealing
high degrees of intra-individual polymorphism connected with the presence of pseudogenes has risen. The 5.8S rDNA is the most
important diagnostic marker for functionality of the ITS region. In Mammillaria, intra-individual 5.8S rDNA polymorphisms of up to 36% and up to nine different types have been found. Twenty-eight of 30
cloned genomic Mammillaria sequences were identified as putative pseudogenes. For the identification of pseudogenic ITS regions, in addition to formal
tests based on substitution rates, we attempted to focus on functional features of the 5.8S rDNA (5.8S motif, secondary structure).
The importance of functional data for the identification of pseudogenes is outlined and discussed. The identification of pseudogenes
is essential, because they may cause erroneous phylogenies and taxonomic problems.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
8.
紫距淫羊藿为根据少量栽培个体描述的中国特有种,狭域分布于湖南省天平山,自发表以来未见后续形态学研究。为了掌握紫距淫羊藿形态变异式样并为该物种及其近缘种的分类提供依据,该研究在模式产地湖南省桑植县天平山,于花果期开展野外居群的形态观测,对紫距淫羊藿主要性状进行变异分析以及形态描述的完善或修订,并提供了该物种的形态图片资料。结果表明:基于野外观测,紫距淫羊藿主要形态性状的变异范围均远超出物种发表原始文献的描述,如株高12.0~68.0 cm,大幅度高于原始描述的12cm;居群内结节状根茎和细长根茎并存,且两种类型的个体数量相当;其余性状,如叶长、叶宽、花序轴长、花色等都呈现丰富变异。此外,还补充描述了紫距淫羊藿的果实和种子的性状,蓇葖果长8~13 mm,内含种子2~11粒,种子具油质体。因此,分类学描述应重视野外观察,特别要注意个体间的变异并进行性状分析,这是分类研究的基础。 相似文献
9.
Many lineages of land plants (from lycopsids to angiosperms) have non-photosynthetic life cycle phases that involve obligate
mycoheterotrophic arbuscular mycorrhizal (AM) associations where the plant host gains organic carbon through glomalean symbionts.
Our goal was to isolate and phylogenetically identify the AM fungi associated with both the autotrophic and underground mycoheterotrophic
life cycle phases of Psilotum nudum. Phylogenetic analyses recovered 11 fungal phylotypes in four diverse clades of Glomus A that form AM associations with P. nudum mycoheterotrophic gametophytes and autotrophic sporophytes, and angiosperm roots found in the same greenhouse pots. The correspondence
of identities of AM symbionts in P. nudum sporophytes, gametophytes and neighboring angiosperms provides compelling evidence that photosynthetic heterospecific and
conspecific plants can serve as the ultimate sources of fixed carbon for mycoheterotrophic gametophytes of P. nudum, and that the transfer of carbon occurs via shared fungal networks. Moreover, broader phylogenetic analyses suggest greenhouse
Psilotum populations, like field-surveyed populations of mycoheterotrophic plants, form AM associations with restricted clades of
Glomus A. The phylogenetic affinities and distribution of Glomus A symbionts indicate that P. nudum greenhouse populations have the potential to be exploited as an experimental system to further study the physiology, ecology
and evolution of mycoheterotrophic AM associations.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
10.
11.
Toshiyuki Sato 《Journal of plant research》1986,99(4):361-377
An intra-species comparison of the life history of various populations ofPolystichum tripteron was undertaken in Hokkaido and Honshu in Japan with respect to some leaf-size characters and fertility during sporophyte
development. The developmental process of sporophytes was quantitatively estimated by counting the number of venation (NV:
number of midrib branches of the leaf). The mean NV of the fertile leaves decreased slightly with increasing altitude on Mt.
Teine near Sapporo and with increasing latitudes from Honshu to Hokkaido. The blade length was longer at any NV in Hokkaido
populations than in those of southern Honshu. Longer blade (BL) and pinna length (PL) and lesser number of pinnules of the
lowest pinna (NPLP) versus NV were observed in leaf populations from Hokkaido than in those from southern Honshu. The maximum
values of lowest pinna length (LPL), NV, number of costa branches (NVLP) and number of pinnule (NPLP) were larger in southern
Honshu than in Hokkaido. In the course of leaf-shape formation represented by the ratio of PL to BL versus NV, the Kyoto population
seemed to be more differentiated into long-lanceolate fronds than did the Hokkaido population. Initiation of fertility in
the sporophyte development and the maximum NV seemed to decrease with increasing altitudes and latitudes in Japan.
Contribution No. 2885 from the Institute of Low Temperature Science, Hokkaido University. 相似文献
12.
N. M. Solov'eva M. G. Pimenov M. G. Vasil'eva N. N. Žigareva V. D. Turkov 《Plant Systematics and Evolution》1985,151(1-2):89-101
A study of morphometric karyotype characters was carried out in 14 species ofPeucedanum s. lat. (Umbelliferae — Apioideae) and in one species of the related genusLomatium. The differences of the species in their karyotype characters are correlated only to a limited degree with their similarities
of dissimilarities in morphological (i. a. carpological) characters, and thus with their taxonomic position. The evolution
of these two sets of characters seems to have proceeded not synchronously or even in different directions in the group of
platycarpousUmbelliferae united in the genusPeucedanum. Therefore, it is unlikely that morphometric chromosome characters revealed by monochrome staining can be used appropriately
in the taxonomic revision of the polymorphous genusPeucedanum. 相似文献
13.
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
14.
Genetic diversity of rhizobia associated with <Emphasis Type="Italic">Vicia faba</Emphasis> in three ecological regions of China 总被引:1,自引:0,他引:1
Great genetic diversity was revealed among 75 rhizobal isolates associated with Vicia faba grown in Chinese fields with AFLP, ARDRA, 16S rDNA sequencing, DNA–DNA hybridization, BOX-PCR and RFLP of PCR-amplified nodD and nodC. Most of the isolates were Rhizobium leguminosarum, and six isolates belonged to an unnamed Rhizobium species. In the homogeneity analysis, the isolates were grouped into three clusters corresponding to (1) autumn sowing (subtropical)
region where the winter ecotype of V. faba was cultivated, (2) spring sowing (temperate) region where the spring ecotype was grown, and (3) Yunnan province where the
intermediate ecotype was sown either in spring or in autumn. Nonrandom associations were found among the nod genotypes, genomic types and ecological regions, indicating an epidemic symbiotic gene transfer pattern among different genomic
backgrounds within an ecological region and a relatively limited transfer pattern between different regions. Conclusively,
the present results suggested an endemic population structure of V. faba rhizobia in Chinese fields and demonstrated a novel rhizobium associated with faba bean.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
15.
Han Gil Choi Young Sik Kim Soon Jeong Lee Ki Wan Nam 《Journal of applied phycology》2007,19(2):131-138
Monthly growth and reproduction of Undaria pinnatifida sporophytes were examined over a period of 5 months in a cultivation farm in Korea. A total of 11 characters of Undaria were measured to determine a reliable morphological character representing its growth and reproduction. Plant weight of Undaria sporophytes increased steadily over the experimental period, but it increased in four different ways. Undaria pinnatifida increased body weight by growth in length and width (October–early December), and by growth in width with the thickening
of blade and stipe when sporophytes began to be fertile (December–January). In the middle of January, growth in length and
width had almost stopped with the maturation of Undaria sporophytes. Finally, the weight of Undaria increased again by growth in width at the end of February. Present results indicate that Undaria sporophytes increase body weight by growth in length and width at different times, and the relationship between reproduction
and vegetative growth is exclusive. Plant weight was positively correlated and fitted well with stipe width and blade width.
The blade of Undaria was very thin (ca. 254 μm) and breakable by wave action, but its stipe was strong and relatively thick (ca. 8.7 mm). Furthermore,
the fertility of U. pinnatifida was fitted better with stipe width than blade width. Thus, we suggest that the stipe width is the most feasible character
with which to estimate the growth and reproduction of U. pinnatifida sporophytes in the cultivation farm. 相似文献
16.
We tested whether maternal effects have led to the adaptive divergence of strains of the natural hybrid Potamogeton anguillanus, whose putative parents show contrastingly divergent ecologies. To examine the correlation between phenotypic characters
and maternal types, we conducted drought experiments and DNA typing using nuclear and chloroplast genes. In the field, we
investigated the distribution of the maternal type along the depth and the inshore-offshore gradient. Hybrids of P. malaianus mothers (M-hybrids) and those of P. perfoliatus mothers (P-hybrids) could not be distinguished morphologically under submerged conditions, but differed in drought tolerance.
M-hybrids and P. malaianus formed more terrestrial shoots and exhibited higher survival than P-hybrids and P. perfoliatus in drought experiments. The distribution survey clarified that M-hybrids were dominant in shallow and inshore areas, whereas
they were almost absent in deeper and offshore areas. These results indicate that the natural hybrid P. anguillanus differs in adaptive values depending on the maternal type. Bidirectional hybridization and heritable maternal effects may
have played important roles in its phenotypic adaptation to local environmental conditions.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
17.
Delimiting species boundaries within Dermanyssus Dugès, 1834 (Acari:Dermanyssidae) using a total evidence approach 总被引:1,自引:1,他引:0
L. Roy A.P.G. Dowling C.M. Chauve T. Buronfosse 《Molecular phylogenetics and evolution》2009,50(3):446-470
The genus Dermanyssus is currently composed of 24 hematophagous mite species and includes the Poultry Red Mite, Dermanyssus gallinae, a serious pest in poultry houses. Morphologically, Dermanyssus species fall into two groups corresponding to Moss’ gallinae-group and to hirsutus-group + Microdermanyssus. Species of the gallinae-group exhibit high levels of morphological variability, and are nearly impossible to distinguish. Species of the second group display consistent characters and host associations and are easily distinguishable. Species of the gallinae-group tend to be the major problems in poultry houses and it is unknown whether D. gallinae is the only pest, or if there are numerous cryptic species present in the system.Twenty species of Dermanyssus were tested phylogenetically based on 46 morphological characters. A subset of species, mainly of the gallinae-group, represented each by several populations, was sequenced for two mitochondrial and one nuclear gene regions. This allowed testing their specific status and their interrelationships based and on morphological and molecular characters. The molecular data was analysed separately and in combination with morphological characters. As expected, morphology did a poor job resolving relationships.Molecular data proved more informative. The resulting phylogenetic hypotheses brought some information about interrelationships among species of the gallinae-group showing a split into two main clades. The invasion of human managed environments seems to occur only in taxa within one of the two clades. The host spectrum seems to get enlarged in more derived taxa in the same clade. A delineation of six species within the gallinae-group is provided. Additionally, a key for morphological identification of these species is provided. D. gallinae appears to be the only pest in poultry houses, but is composed of several different and more or less strongly isolated lineages. A new species found from the black swift is described. 相似文献
18.
We compared the distributions of Alouatta palliata and A. pigra in southeastern Mexico and Central America with geographic and ecological features to infer current barriers and ecological
preferences. Distribution data were obtained from museum specimen localities, study sites, historic records and field surveys
and integrated into digital elevation and ecosystem maps using GIS. A. pigra evidently occurs at a number of sites above 2,000 m, where temperatures can even drop below zero on some days of the year,
thus indicating a broader ecological tolerance than previously reported. Both species occupy a number of vegetation types
and can be found in seasonal and nonseasonal forests. We identified the highland massif of northern Central America and its
associated coniferous and subalpine vegetation as a geographic barrier that separates the species. In the past, distribution
maps for these species have indicated adjacent contiguous ranges, but we propose that they are largely separated by these
mountains. There are two contact zones: a broad area of sympatry north of the highland massif in Mexico and a narrow zone
in eastern Guatemala where parapatry is maintained by a river barrier and where only A. pigra occurs in the high elevations and cooler habitats inland. We explore an alternative biogeographic scenario for the split
of the two species that accounts for the current distribution and differences in elevation and cold tolerances.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
19.
The classification methodology based on morphometric data and supervised artificial neural networks (ANN) was tested on five
fly species of the parasitoid genera Tachina and Ectophasia (Diptera, Tachinidae). Objects were initially photographed, then digitalized; consequently the picture was scaled and measured
by means of an image analyser. The 16 variables used for classification included length of different wing veins or their parts
and width of antennal segments. The sex was found to have some influence on the data and was included in the study as another
input variable. Better and reliable classification was obtained when data from both the right and left wings were entered,
the data from one wing were however found to be sufficient. The prediction success (correct identification of unknown test
samples) varied from 88 to 100% throughout the study depending especially on the number of specimens in the training set.
Classification of the studied Diptera species using ANN is possible assuming a sufficiently high number (tens) of specimens
of each species is available for the ANN training. The methodology proposed is quite general and can be applied for all biological
objects where it is possible to define adequate diagnostic characters and create the appropriate database. 相似文献
20.
The distribution of Daphniaspecies in tropical Africa is poorly known and understood. Daphniaare assumed rare in tropical regions, but systematic studies covering large areas are sparse. We sampled the active community
(live zooplankton) and/or the dormant community (diapausing egg banks in the sediment) of 41 standing water bodies in Kenya
in search for Daphnia.Overall the dormant communities yielded 11 species of Daphnia, a species richness more than twice the species richness found in the active communities. Dormant community species diversity
better reflects the spatial, and particularly the temporal (multi-annual) variation in environmental conditions available
to Daphniain these tropical standing waters. Hence, we suggest that the dormant community be taken into account when assessing local
zooplankton diversity, especially in fluctuating tropical lake ecosystems, where the presence of each local Daphniaspecies in the active community may be strongly seasonal or erratic. Geographic distribution data from this study are supplemented
with previous records of Daphniain East Africa to provide an overview of the known distribution of Daphniain Kenya and neighbouring countries. We also present a detailed key for morphological identification of the ephippia of the
11 Daphniaspecies encountered, complemented with photographs and drawings of diagnostic characters. 相似文献