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1.
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
2.
Edison José de Paula Cintia Erbert Ricardo Toledo Lima Pereira 《Phycological Research》2001,49(3):155-161
Unialgal cultures were established trom a 2.5 g branch ot a brown variant ot Kappaphycus alvarezii (Doty) Doty ex P. Silva, with the main objective to produce branches for monthly outplanting in the sea. Ditterent conditions were tested to optimize production ot branches in the laboratory. The best growth was obtained under culture conditions of 25 ± 2°C, 170–210 μmol photons m2 s?1, 14:10 LD photoperiod and salinity 32–35‰. Three culture media (Provasoli,‘F/2’and von Stosch) were tested. Deleterious ettects were observed in branches incubated continuously in full‐ or halt‐strength Provasoli's enriched seawater medium (PES). Exponential growth rates ot about 3% day?1 were obtained using PES, pulse‐fed 24 h per week, or other diluted media used continuously (one‐quarter strength ‘F/2’and half‐strength von Stosch). Laboratory‐grown branches with mean weights from 2.97 to 4.25 g were successfully introduced into the sea at Ubatuba, SP, Brazil (23°26.9′S, 45°0.3′W) an area with mean monthly seawater temperature from 20.3 to 28.5°C (extremes: 17.0–31.0°C). Transplantation of branches produced in unialgal culture, as done in the present study, avoids the risk of introduction of unwanted species into new areas. 相似文献
3.
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
4.
Juan E. Macchiavello A. Cristian R. Bulboa C. Mario Edding V. 《Phycological Research》2003,51(1):45-50
In the present study we compared vegetative and spore‐based propagation for Chondracanthus chamissoi (C. Agardh) Kützing. Monthly field observations were made over a 1‐year period at Puerto Aldea, Tongoy Bay, Chile. Data were collected both outside and within a bed of C. chamissoi. Vegetative propagation was assessed via attachment of drifting fronds to shell‐encrusted concrete blocks at both sites. Germination of spores was recorded on the same shell substrates. Substrate re‐adhesion varied seasonally between sectors. Highest averages occurred within the algal bed between January 1997 and March 1997. The number of sporelings showed two peaks of maximal recruitment in spring and summer months (January‐March 1997 and September 1997‐January 1998). Spore‐based propagation is an important mechanism of seasonal regeneration of biomass in the C. chamissoi bed; however, re‐attachment of fronds may have been important in maintaining production of the bed during the period of maximum biomass accumulation. 相似文献
5.
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
6.
Héctor Romo Marcela Avila Mario Núñez Rodrigo Pérez A. Candia Gesica Aroca 《Journal of applied phycology》2006,18(3-5):307-314
In the last 10 years studies on the management and exploitation of Chilean carrageenophytes have proliferated in response to the increasing development of the local processing industry. One of the most important sources of raw material for Chilean carrageenan, Gigartina skottsbergii Setchell et Gardner, was the subject of an intensive study to design a commercial cultivation technique which could be an alternative to wild harvest. In this context this pilot study reports the first successful attempt to culture G. skottsbergii from spores to harvestable plants. A three-step farming approach was developed: (i) seeding of spores onto scallop shells followed by a two-month nursery period in a greenhouse (until the development of initial upright thalli from the discoid crust occurred), (ii) outplanting juvenile plants on shells in the sea on a long-line system (until thalli attained 3–4 cm diameter) and (iii) detachment of fronds from the shells, fixing of individuals to vertical ropes and growth until commercial size was reached. Additional experiments to compare bottom and suspended growth, cultivation by fragmentation and whole fronds and meristematic activity of different zones of the fronds were performed. This study shows the technical feasibility of culturing G. skottsbergii from spores, complemented with growth of vegetative fragments, in order to optimize the management of the culture. In the future, therefore, it may be possible to replace the heavy exploitation of wild beds in southern Chile with farming activities. 相似文献
7.
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
8.
9.
The nuclear genes encoding small-subunit ribosomal RNAs (ssu-rDNAs) of the carrageenophytes Eucheuma denticulatum, E. isiforme and Kappaphycus alvarezii were amplified by the polymerase chain reaction, cloned and sequenced. The sequences range from 1767 (K. alvarezii) to 1781 (E. isiforme) nucleotides in length, and have guanine+cytosine contents between 51.2% (E. isiforme) and 51.5% (E. denticulatum). Pairwise sequence identities among these sequences ranged from 97.6% to 98.5%, levels comparable to some intergeneric identities
within Gracilariales. In phylogenetic analyses, the two Eucheuma ssu-rDNAs group stably together vis-a-vis the ssu-rDNA of K. alvarezii, and these three ssu-rDNAs form a monophyletic group within a larger grouping of other carrageenophytes. The results demonstrate
quantitatively that analysis of nuclear-encoded ssu-rDNA sequences is likely to be useful in resolving taxonomic, phylogenetic
and biogeographic questions among tribe Eucheumatoideae Doty. 相似文献
10.
Abiotic and biotic factors affecting seasonal variations in the biomass andreproductive condition of Chondracanthus chamissoi were evaluatedin a population at La Herradura Bay, northern Chile. During spring,increase in temperature, light, and photoperiod favored the reproductiveactivity of C. chamissoi, contributing to its growth and production ofreproductive biomass. During summer, extremes of temperature and lightavailability were accompanied by bleaching of the thalli, followed bydecomposition and biomass loss, significantly lowering production.Epiphytism and herbivory showed were then at their maximum. Analysis offertility showed that C. chamissoi was in reproductive conditionthroughout the year, with maximum for cystocarpic and tetrasporic plantsduring spring, significantly correlated with total biomass production.Production and liberation of spores and other values for reproductivecapacity showed the highest values in spring. The results of the study,coupled with information from the literature, recommend two commercialharvests during spring, at a time when standing crops are the highest, andvalues for reproductive condition predict adequate expression of the sexualphase. The time of the year suggested as adequate for commercial harvestof this alga probably coincides with the highest quality of its carrageenans,and would precede the phase of local growth cycle, where its biomassbegins to deteriorate due to bleaching, epiphytism and herbivory. 相似文献
11.
Hypnea musciformis is the only species so far exploited in Brazil as raw material for the production of k-carrageenan. Due to the erratic production in space and time, increasing harvest and transportation costs, experiments have been performed in order to assess the viability of H. musciformis mariculture.In nature the species occurs as an epiphyte, and so mariculture using artificial substrates that simulated the natural host of the species was tried. These substrates were attached, at regular intervals, to linear ropes. In the sea, these ropes were stretched between cement blocks.Seeding occurs naturally, by means of spores, or detached pieces of H. musciformis scattered in the water column that get entangled on the ropes. The best yields (0.54 wet kg m–1 month–1) were obtained with unthreaded rope substrates maintained in a vertical position by small rafts. Production is highest in the first 18 m off the rocky shore (0–2.1 m deep), at the highest substrate density utilized (10 m–1), 2–3 months after installing the ropes in seawater. The main factor controlling seasonal production is water movement. 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.
A. Q. Hurtado-Ponce 《Journal of applied phycology》1992,4(4):311-313
Kappaphycus alvarezii var.tambalang was cultured in a 3 × 3 m bamboo raft installed inside a 4 × 4 m floating net cage ofLates calcarifer (sea bass) broodstock at SEAFDEC Sub-station Igang, Guimaras, Philippines, from December 1989 to May 1990. Growth and production ofK. alvarezii var.tambalang was influenced by the culture months. The highest growth rate and production were recorded in January and May, respectively, while the lowest growth rate and production were observed in March. Average growth rate (wet weight) ranged from 3.72 to 7.17% day-1, while production ranged from 575.5 to 2377 g m-1 line-1. A total production of approximately 123 t (fresh) or 37 t (dried) ha-1 in the 5-month harvest season was produced from this culture system. Cultivation ofK. alvarezii var.tambalang in cages is possible, which indicates that seaweeds can be grown with carnivorous finfish, a practice which is still untapped. 相似文献
14.
Every year, several hundred tonnes of dry Gymnogongrus furcellatus are exported from Chile for carrageenan production. The present study provides ecological information for rational harvesting
practices, including an understanding of the effects of environmental factors on growth. Field results indicate that the species
is abundant in areas where disturbing factors do not destroy the crustose base of the plants, which can survive sand burial,
but is grazing sensitive. In central Chile the erect axes have a clear seasonal pattern of growth which, as extrapolated from
laboratory experiments, is most affected by seasonal changes in quantum dosage and photoperiod. Laboratory experiments show
that vitamins and CO2 additions also influence growth rates significantly. Field data indicate that harvesting in central Chile should be done
bi-monthly, within the six most productive months of the year and be stopped before March, when the female gametophytes become
fertile. Hand picking is the least destructive harvesting method. Even though the daily growth rate of the species could be
raised to 7% in laboratory experiments, tank cultivation appears uneconomical. The cost of some of the factors required for
the growth of this species, such as daily vitamin additions, aeration and CO2 supplements, are unlikely to be recovered by the 25% average carrageenan content of this species. In addition, the high light
requirements of the species would restrict culture to only 6 months a year at these latitudes. Therefore adequate management
of the beds is required for sustained production. 相似文献
15.
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
16.
Gigartina skottsbergii is a commercially important carrageenan producer that has been suffering severe extraction pressure in Chile’s Magellan Region
and Cape Horn Archipelago since 1998. In order to create baseline information for its cultivation and repopulation, we studied
the effects of agricultural fertilizers on growth of G. skottsbergii early developmental stages. The culture media utilized were: a) seawater + Bayfoland, b) seawater + Superphosphate, c) seawater
+ Urea, d) seawater + Provasoli and e) seawater as a control. The culture conditions were: a) 12L:12D photoperiod; b) temperature
8 ± 1°C and c) irradiance at 45 μmol photons m−2 s−1. After 60 days, higher relative growth rates between treatments were observed; the treatments that included Bayfoland and
Provasoli showed greater growth (382 ± 55 and 378 ± 50 μm, respectively,) compared to Superphosphate (88 ± 16 μm), control
(78 ± 10 μm) and Urea (70 ± 11 μm) treatments, after 81 days. The Urea treatment and the control had inhibitory effects on
G. skottsbergii germlings growth and survival, as evidenced by progressive loss of pigmentation and death after 60 days. These results showed
that Bayfoland was an excellent alternative to develop cultures. 相似文献
17.
Photoautotrophs can cope with an increase in ultraviolet (UV) irradiance in the aquatic environment, through protection and acclimation mechanisms (i.e. synthesis of UV-absorbing compounds). This capacity has been proven to vary according to the organism's sensitivity. To quantify variations of this capacity between the different parts of macroalgae, an in vitro study was performed with the tips, cystocarps and thalli segments of Gracilaria chilensis. Whole algae incubated during 3 days at high and low PAR, supplying UV B (4.6 µW cm–2) during 2 hours showed, as predicted, an increase in absorption (OD) at 320 nm of the different parts, after the first day of exposure to UV B. The tips presented the highest increase in the standardized OD at 320 nm relative to cystocarps and thalli segments; their mean percentage of increase was 38% and 29% at low and high PAR, respectively. The lowest sensitivity was consistently found in the thalli segments, while the highest was in the tips. The tips are important for growth and therefore they play a major role in the maintenance of the Gracilaria populations. Acclimation mechanisms that occurred in a short time scale, and mainly in the tips, may allow Gracilaria to have an almost immediate protection to increases in UV B fluxes. 相似文献
18.
Cystocarpic branches of a species of Gracilaria from Coquimbo, Chile, were cultured in vitro. A Polysiphonia-like life history was completed in about 6 months, but some abnormalities were observed: i. carpospores gave rise to plants producing either tetrasporangia and spermatangia, or tetrasporangia only; ii. tetraspores cultured without aeration developed into plants bearing spermatangia only; tetraspores cultured with aeration developed into 1:1 female and male gametophytes; iii. plant originated from tetraspore produced spermatangia and tetrasporangia; one of these tetraspores developed into a male gametophyte; iv. some tetraspores gave rise to spherical bodies instead of the ordinary cylindrical branches; one of them bore spermatangia after three months. The results show that environmental factors seem to be interfering with the mechanism of sex determination and induce the development of spermatangia on putative female gametophytes, or on putative tetrasporophytes.
Noted added in proof: The Gracilaria sp. studied here was recently described as a new species, G. chilensis by Bird C. J., McLachlan, J & Oliveira, E. C. de, 1986. Can. J. Bot. 64: 2928–2934.
Noted added in proof: The Gracilaria sp. studied here was recently described as a new species, G. chilensis by Bird C. J., McLachlan, J & Oliveira, E. C. de, 1986. Can. J. Bot. 64: 2928–2934. 相似文献
19.
We examined whether auxins and cytokinins, either singly or in combination, stimulate cell division in tissue cultures of a red seaweed. Our experimental model consisted of filamentous and callus-like growths that developed from cross-sectional discs cut from young branches of Agardhiella subulata. Plant growth regulators were added to the medium to give combinations of an auxin with a cytokinin over a range of concentrations (1 µg L–1 –10 mg L–1). Several mixtures of auxins and cytokinins, as well as some single auxins, cytokinins and phenolics, stimulated cell division and growth in the tissue cultures beyond that of controls. The treatments that were effective included: phenylacetic acid/zeatin; phenylacetic acid/6-benzylaminopurine; -naphthaleneacetic acid/zeatin; 2,4,5-trichlorophenoxyacetic acid/6-benzylaminopurine; and indoleacetic acid/kinetin. High concentrations of cytokinins (i.e. 10 mg L–1) inhibited the regeneration of plants in some of the cell cultures. These results provide further evidence that growth regulators can be used for the tissue culture of seaweeds and for the study of developmental phenomena in these plants. 相似文献
20.
Kazuo Kasahara 《Journal of plant research》1980,93(2):117-123
Turnerella (Gigartinales) withT. mertensiana known from northern Japan was studied to determine its life history. Carpospores cultured from foliose female plants gave
rise on germination to crustose plants containing tetrasporangia, as noted previously inT. pennyi from the Atlantic. The crusts were slow to develop and required 3–5 years to achieve reproductive maturity.
Tetraspores liberated in culturedT. mertensiana gave rise on germination eventually to thalli similar to gametophyticT. mertensiana. Thus this species may be said to adhere to the pattern of life history in which a large, foliose gametophyte alternates
with a small crustose tetrasporophyte. The erect filaments of the small sporophytes branch laterally and tetrasporangial mother
cells are found there, exemplifying an unusual method for crustose species to produce tetrasporangia. 相似文献