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1.
The life history of the red alga Ahnfeltiopsis paradoxa (Suringar) Masuda (Phyllophoraceae, Gigartinales) from Japan was completed in laboratory culture. Carpospores isolated from field-collected plants germinated to form circular crusts that were composed of a monostromatic hypothallium consisting of radiating filaments, a polystromatic perithallium consisting of tightly coalescent erect filaments, and hypobasal tissue derived from the hypothallium. The crusts were induced to sporulate by transferring them from short-day to long-day regimes at 15° and 2°C. Each crust produced several nemathecia along 1-4 concentric rings. Intercalary, cruciately or decussately divided tetrasporangia were formed in 4-6 (1-2 at the margin of the nemathecium) successive cells of a single filament of the nemathecia. Tetraspore germlings gave rise to basal discs from which upright axes developed. The upright axes first grew without branches or were sparsely branched and later bore many marginal reproductive proliferations. Procarps and spermatangia were formed in the proliferations on different individuals. Carposporophytes developed on female plants that were co-cultured with male plants. Gonimoblast filaments were formed from an auxiliary cell that fused with a carpogonium. Carposporangia developed from gonimoblast filaments and medullary cells contacted by the gonimoblast filaments. Carpospores were discharged through carpostomes formed in the thickened cortex. Tetraspores were cultured from field-collected crusts of a morphology similar to that of cultured tetrasporophytes. They gave rise to upright gametophytic axes similar in morphology to this species as seen in the field. 相似文献
2.
3.
Cultivated Chondrus crispus was used in N-NH4 uptake experiments in the laboratory. An elevation of temperature increased the apparent rate of uptake, especially up to 11 °C. Uptake in the dark was found to be 83 % of that in the light. The apparent uptake decreased with increasing internal N pool; rates were 26.5, 22.2 and 20.2 µg N g dry wt–1 min–1 for internal N pools of 2.7, 3.5 and 4.6%, respectively. Apparent uptake increased with the substrate N concentration. The resulting curve has two components: an active uptake and a diffusion component at high (> 5000 µg N L–1) external N levels. Ks and V
max were calculated by deducting the diffusion component from the uptake curve: these were of 497 µg N L –1 and 14.4 µg N g dry wt–1 min–1. respectively, and reflect a low substrate affinity. This could be the result of 10 years of continuous culture of C. crispus. Uptake was similarly followed in the culture tanks and showed comparable results; nighttime would be the most appropriate time to supply nutrients. 相似文献
4.
Apical callus formation in Solieria filiformis (Gigartinales,Rhodophyta) cultured in tanks 总被引:1,自引:1,他引:0
Loose-lying wild plants of the carragenophyte Solieria filiformis (Kützing) Gabrielson were cultivated under greenhouse conditions in 600 l tanks in stationary and turbulent cultures, produced either by air bubbling or water jets at the bottom of the tanks. One week after inoculation 90.3% of the apices of the plants grown in air turbulent cultures initiated the formation of callus. The apices were not broken and apparently non-wounded. No callus formation were observed from a few accidentaly broken apices in any culture. Only 4% of the apices in water turbulent cultures induced callus. Reorganization of branches from the calli took place after three weeks. Organogenetic calli detached from the mother plant after four weeks and formed spherical masses of 3 cm in diameter growing as unattached balls. Cellular disorganization (i.e. callus formation) in S. filiformis seems to be a consequence of intermittent abrasion or contact stimuli against tank walls produced by turbulence. 相似文献
5.
Ricardo Scrosati 《Journal of applied phycology》2004,16(1):69-72
Mathematical modelling is useful in population ecology and resource management. Logistic models have traditionally been applied
to unitary organisms, but it is unclear whether they could be used at the frond (ramet) level for clonal seaweeds. This study
shows that frond dynamics for the clonal seaweed Mazzaella parksii (=M. cornucopiae) can be described by a discrete-time logistic model. The model is realistic in that it includes density-dependence, which
was previously demonstrated experimentally for this species, and only necessitates data on frond density measured at discrete
time intervals. This may constitute a useful tool for the management of clonal seaweeds of economic importance that occur
in dense stands.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
6.
Systematic studies of the antarctic species of the phyllophoraceae (Gigartinales,Rhodophyta) based on rbcL sequence analysis 总被引:1,自引:0,他引:1
The taxonomic placement of four antarctic species of the marine red algal family Phyllophoraceae (Gigartinales) is assessed within a preliminary molecular phylogeny of the family based on direct sequence analysis of the chloroplast gene rbcL. Parsimony analysis of rbcL sequences indicates that Gymnogongrus antarcticus and Gymnogongrus turquetii cluster in a clade consisting predominantly of southern hemisphere species currently placed in Gymnogongrus and Ahnfeltiopsis, whereas Phyllophora ahnfeltioides and Phyllophora antarctica cluster in a separate clade that is widely divergent from the northern hemisphere Phyllophora clade. Results from molecular and morphological data challenge the current taxonomic concept that type of life history is a phylogenetically valid criterion for recognition of genera in the Phyllophoraceae. 相似文献
7.
Ricardo D. Otaíza Sebastián R. Abades Antonio J. Brante 《Journal of applied phycology》2001,13(2):161-171
The population dynamics of the carrageenophyte Sarcothalia crispatais described from subtidal beds at two localities in south-central Chile. Seasonal fluctuations in total density and biomass were not evident. Frondswere identified to phase by the presence of reproductive structures and theresorcinol reaction. The monthly changes in abundance of each kind offrond were determined. Permanent gametophytic or sporophyticdominance was not evident: the more exposed site showed a seasonal shiftfrom sporophytic dominance in summer to gametophytic dominance inwinter, whereas the more protected site showed an interannual shift fromgametophytic to sporophytic dominance. The differences between localitiesand years suggest a very local population dynamics with large contributionof self-seeding to the maintenance of the S. crispata beds. 相似文献
8.
The appearance of cavities and holes in fronds of commercially cultivated Chondrus crispus is described. These ultimately arise from the ravages of a green spot or green rot disease system in which several biotic agents can participate. Nematodes capable of bacterial grazing were recovered from necrotic lesions and we suggest that the nematodes can facilitate wound healing in diseased tissues. Bacteria isolated from disease lesions and from the surfaces of healthy fronds were screened for pathogenic strains. A particularly virulent one, the DOR isolate, was purified from small dark orange colored colonies grown on dilution plates. It was present in necrotic tissue and also recovered from surface scrapings of old healthy fronds, but not from their apical regions. Growth of the DOR isolate appeared to be inhibited by other bacteria colonizing the algal surface. It was shown to be a facultative pathogen, the virulence of which depended on the availability of ammonium or constituents easily metabolized to ammonium. It induced green rot disease in healthy C. crispus and was recoverable in pathogenic form from experimentally infected frond apices. A wound, disease and recovery cycle is discussed to illustrate potential interrelationships involving animal grazers, algal endophytes, Petersenia pollagaster, bacteria and nematodes. 相似文献
9.
Juan Luis Gómez Pinchetti Mats Björk Marianne Pedersén Guillermo García Reina 《Plant cell reports》1993,12(10):541-545
Summary The effect of age, pH of the culture medium, pre-treatment of tissues, enzymes sources and enzymatic adaptability of phycophages fed with a monospecific diet were analyzed on the protoplast yields of the red seaweed Solieria filiformis (Kützing) Gabrielson. New apices from fast growing plants showed the highest protoplast yields. The protoplast yield decreased when the pH of the culture medium increased from 6.0 to 9.0. Crude extracts from the abalone Haliotis coccinea canariensis Nordsieck, fed with Solieria filiformis thalli for three months in combination with cellulysin, released the highest number of viable cells and protoplasts. Yields ranged from 1.0 to 8.5 x 106 protoplasts per gram of fresh weight.Abbreviations AAP
abalone acetone powder
- Bis-Tris
Bis(2hydroxyethyl)imino-tris(hydroxymethyl)methane
- CMC
carboxymethyl cellulose
- EDTA
ethylenediaminetetraacetic acid
- EGTA
ethylene glycol-bis(ß-aminoethyl ether) NNNN-tetraacetic acid
- FDA
fluorescein diacetate
- FW
fresh weight
- Hepes
N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid
- Tris
Tris(hydroxymethyl)aminomethane 相似文献
10.
Observations on JapaneseSyringoderma from Rishiri Island, which had been previously identified asS. australe, were made based on newly collected fertile material. These results and comparisons with the type specimen ofSyringoderma abyssicola (=Chlanidophora abyssicola) revealed that the Rishiri Island plants should be identified asSyringoderma abyssicola. Syringoderma abyssicola from Rishiri Island formed unilocular sporangia among the paraphyses on the fan-shaped blades in winter. The first products
(uni-spores) in the unilocular sporangia form flagella, and soon after form cell walls before release. Then these reduced
gametophytes divide into tetrads and form swarmers, each of which contains a chloroplast with a stigma. These swarmers germinate
into branched filaments, from which thicker erect filaments of apical growth tissue. At 5–10 C these erect filaments formed
fan-shaped blades under long-day conditions, and unilocular sporangia under short-day conditions corresponding respectively
to spring and winter at Rishiri Island. Accordingly, the seasonal growth pattern of the species is considered to be controlled
by responses to photoregime and temperature.
Dedicated to the memory of the late Professor Muneao Kurogi. 相似文献
11.
Field observations in sublittoral Prince Edward Island, Canada, indicated that on a friable sandstone substratum Chondrus crispus was more commonly associated with Phymatolithon sp. than with bare rock. Thus, a substantial proportion of the population of Irish moss along the coast of Prince Edward Island occurs on this encrusting coralline. These observation may be explained on the basis of the relative stability of the substratum in contrast to other studies in which sloughing of epithallial cells by species of both Phymatolithon and Lithothamnium has been reported to limit epiphytism by fleshy macrophytes.Issued as NRCC 31426. 相似文献
12.
Vegetative reproduction of Chondracanthus chamissoi by means of fragmentation and re-attachment of thalli is considered an effective strategy for maintaining natural populations
of this species. Here, we evaluate the effects of (1) time of drifting thallus, (2) type of substratum, and (3) photon flux
density, on the re-attachment capacity of thallus fragments of C. chamissoi. The results show that re-attachment decreases with the time after detachment, and was higher at the lower photon flux densities
tested (10 and 40 μmol photons m−2s−1), and on calcareous substratum. Secondary attachment discs are formed along the entire surface of the fragment. 相似文献
13.
S. Afaq-Husain Mustafa Shameel K. Usmanghani Mansoor Ahmad Shaista Perveen Viqar Uddi Ahmad 《Journal of applied phycology》1991,3(2):111-113
A chloroform extract of freeze-dried Hypnea pannosa J. Ag., collected from the intertidal region near Karachi, Pakistan, furnished three bromine-containing secondary metabolites.
These were characterised, using spectroscopic techniques, as 10-bromo-7, 12-dihydroxy-Δ3, 4-laurene, filiformin and filiforminol. This is the first report of halogenated terpenoids from the genus Hypnea.
author for correspondence 相似文献
14.
The phycocolloids of female gametophytes ofGigartina teedii (Roth) Lamouroux harvested in Roscoff (Brittany, France) are a hybrid carrageenan resulting from juxtaposition of fragments of kappa-, iota-and nu-carrageenan. They represent 70% of the dry matter of the alga in summer. After alkaline transformation the proportion of iota-carrageenan increased to 76%, demonstrating the presence of nu-carrageenan. Absence of mu-carrageenan, the precursor of kappa-carrageenan, suggests that iota-carrageenan is desulfated enzymically to kappa-carrageenan. 相似文献
15.
Hommersand Max H. Guiry Michael D. Fredericq Suzanne Leister Geoffrey L. 《Hydrobiologia》1993,260(1):105-120
16.
The effects of environmental factors on substratum coverage, thallus length, production of iota carrageenan and gelling behavior were investigated in field populations of the red algaGymnogongrus griffithsiae (Turner) Martius. Irradiance and water temperature affected thallus substratum coverage and water gel strength of the carrageenan. The significant monthly differences in thallus length, carrageenan content and carrageenan gelling properties were not attributable to seasonal variations in irradiance and water temperature. The effect of temperature and N loading on biomass productivity, carrageenan yield and gelling characteristics were also investigated using cultures. N-enriched cultures showed decreased gel yields, higher viscosities and higher water gel strengths in the carrageenans extracted from these cultures. Milk reactivity tests were correlated with thallus nitrogen and water dessert gel strength, but neither culture temperature nor N loading showed a significant effect. The field and culture studies indicate how temperature, irradiance and N availability affect growth and hydrocolloid production.Author for correspondence 相似文献
17.
Viable protoplasts were isolated from apices of the agarophyte Gelidium robustum (Gardn.) Hollenb. & Abb. using a combination of commercial cell-wall degrading enzymes and extracellular wall-degrading enzymes isolated from a marine bacterium. The protoplasts were approximately 8–15 µm in diameter, liberated mainly from the surface cell layers and from cells at the distal ends of medullary filaments. The bacterial enzyme alone was not sufficient to liberate significant numbers of protoplasts. Maximum yield was 9 × 105 protoplasts/g tissue (wet wt.). Optimum osmolality occurred between 1750–1950 mOs kg–1; yield and viability were severely diminished at osmolalities less than 1350 mOs kg–1. Viability, as determined by flurorescein diacetate staining and Evans Blue exclusion 1 hr after removal from the enzyme solution, was approximately 80–95%. Roughly 80% of the cells did not show Calcofluor fluorescence, while 40% stained positively for the presence of sulfated polysaccharides. Cell wall regeneration was observed with inconsistent reproducibility, and no cell division was observed when the protoplasts were placed in culture medium.Dedicated to the memory of Professor Michael Neushul. 相似文献
18.
N. Bourgougnon M. Lahaye B. Quemener M. Cormaci G. Furnari J-M. Kornprobst 《Journal of applied phycology》1996,8(2):147-153
Chemical and spectroscopic methods showed that the water-soluble polysaccharide extracted fromSchizymenia dubyi from Sicily was composed of 1/0.75/1.3 galactose, glucuronic acids and sulfate groups; 45% of total galactose was present as the L-form and no 3,6-anhydrogalactose was detected. The structural characteristics of this galactan of molecular weight 290 000 were close to sulfated polysaccharide with 1,3-, 1,4- and terminal-linked galactose units and secondary ramifications in 1,3,6; 1,4,6; 1,3,4 and 1,6. Permethylation analysis suggested the presence of sulfate groups on positions O-2 and/or O-3 of 1,4-linked galactose and on O-2 and/or O-4 of 1,3-linked residues.Author for correspondence 相似文献
19.
The basic life history of the red alga Gracilaria is of the three-phase Polysiphonia type but a number of species show deviations. Plants can bear both gametangia and tetrasporangia, either on separate parts
of the thallus or on the same. Explanations include the in situ germination of tetraspores (allowing gametophytic thalli to be epiphytic on tetrasporophytes), the coalescence of spores
or developing discs (resulting in chimaeras), mitotic recombination during cell division in the mature diploid thallus (resulting
in patches of diploid male and female cells on the tetrasporophyte), a mutation eliminating the repression of female expression
allowing haploid male plants to be bisexual and initial failure of cell walls to form during the development of tetraspores.
Polyploids can be produced from plants with diploid gametangia. The sexes and phases are usually morphologically identical
but gametophytes or their parts may be smaller. The growth rates of the sexes may differ and diploid juveniles may survive
better than haploid. Neither polyploidy nor hybridization results in superior growth. The sex ratio is probably 1:1 but females
may appear to be more abundant. Diploid and haploid phases are usually either about equal or diploids predominate, often depending
on the type of substratum. At high latitudes reproduction peaks in late summer whereas in the tropics it may be high all year.
In temperate regions growth rate is fastest and biomass highest in late summer; in the tropics peak biomass is mainly in the
winter. Spermatia are effective for only a few h. Spores vary in size around 25 \m, diploid ones usually being larger. Cystocarps
or tetrasporangia in the field may not currently be releasing spores. In the laboratory spore release shows a diurnal rhythm,
peaking during the night or day according to the species. All the above attributes are potentially important in planning and
executing Gracilaria cultivation. 相似文献
20.
Charles S. Vairappan 《Journal of applied phycology》2006,18(3-5):611-617
Common problems faced in farming of the red algal genus Kappaphycus/Eucheuma are “ice-ice disease” and the occurrence of epiphytes. Considerable work has been documented on “ice-ice disease” and it's mode of infection but limited information is available on the emergence of epiphytes. The present study addresses the phenomenon of epiphyte infection, its prevalence in commercially cultivated red alga, Kappaphycus alvarezii, and their variability associated with seasonality. Cultured seaweed became susceptible to epiphytes in the dry seasons (1) between March – June and (2) September – November. Findings revealed Neosiphonia savatieri (Hariot) M. S. Kim et I. K. Lee, as the dominant infecting epiphyte, representing up to 80–85% of the epiphyte present during peak seasons. Besides N. savatieri, Neosiphonia apiculata, Ceramium sp., Acanthophora sp. and Centroceras sp. were observed in smaller quantities. SEM (Scanning Electron Microscope) micrographs revealed the epiphyte's attachment to the host. Further histological study showed the extent of penetration of epiphytes into the host's cortex tissues and condition of its surrounding tissues. The outbreak of epiphytic filamentous red algae also correlated with drastic changes in seawater temperature and salinity during March– June and September – November. 相似文献