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1.
Cryopreservation of shoot-tips by droplet vitrification applicable to all taro (Colocasia esculenta var. esculenta) accessions 总被引:1,自引:0,他引:1
Rajnesh Sant Bart Panis Mary Taylor Anand Tyagi 《Plant Cell, Tissue and Organ Culture》2008,92(1):107-111
The application of the droplet vitrification cryopreservation technique to taro accessions from a range of Asia Pacific countries
is presented. The optimum protocol involves excision of about 0.8 mm shoot-tips from in vitro plants, 20–40 min PVS2 exposure
at 0°C followed by rapid plunge into liquid nitrogen. Thawing was done at room temperature (25°C) and shoot-tips inoculated
on MS medium with 0.1 M sucrose regenerated into plantlets 4–6 weeks later. This new droplet vitrification protocol improved
the mean post-thaw regeneration rates to 73–100% from 21–30% obtained with the previous cryo-vial vitrification protocol. 相似文献
2.
Factors affecting microspore embryogenesis of cow cockle (Saponaria vaccaria) were evaluated including donor plant growing conditions, genotype, bud size, density, medium composition, and culture conditions.
Of the two donor plant (day/night) temperature regimes evaluated (10/5°C and 20/15°C), plants grown at 20/15°C were the most
embryogenic. An embryogenic frequency of greater than 350 embryos/100 buds was observed in the most embryogenic genotype,
cv. ‘White Beauty’. Buds from 3–9 mm in length were evaluated for their embryogenic potential; buds that were 4–7.9 mm produced
the most embryos/100 buds. Of all the media compositions evaluated, NLN medium with 15% sucrose resulted in the most embryos.
Cow cockle microspores required an initial period of 32°C for 3 days for production of microspore-derived embryos (MDEs). 相似文献
3.
Summary Effects of root temperature on the growth and morphology of roots were measured in oilseed rape (Brassica napus L.) and barley (Hordeum vulgare L.). Plants were grown in flowing solution culture and acclimatized over several weeks to a root temperature of 5°C prior
to treatment at a range of root temperatures between 3 and 25°C, with common shoot temperature. Root temperature affected
root extension, mean radius, root surface area, numbers and lengths of root hairs. Total root length of rape plants increased
with temperature over the range 3–9°C, but was constant at higher temperatures. Root length of barley increased with temperature
in the range 3–25°C, by a factor of 27 after 20 days. Root radii had a lognormal distribution and their means decreased with
increasing temperature from 0.14 mm at 3°C to 0.08 mm at 25°C. The density of root hairs on the root surface increased by
a factor of 4 in rape between 3 and 25°C, but in barley the highest density was at 9°C. The contribution of root hairs to
total root surface area was relatively greater in rape than in barley. The changes in root system morphology may be interpreted
as adaptive responses to temperature stress on nutrient uptake, providing greater surface area for absorption per unit root
weight or length. 相似文献
4.
Seedlings of Arabidopsis thaliana grown at 25°C responded to a change in growth temperature by changing their elongation rate within the next 150 min. Regardless
of whether the new temperature was higher or lower than 25°C, the seedlings grew slower after the transfer at all tested temperatures.
When the seedlings were grown for 2 days at 11.5°C, 17.9°C, and 23.5°C and then transferred to the range of temperatures between
4°C and 38°C they exhibited maximum elongation in the temperature range between 18°C and 23°C. The kinetics of first positive
phototropism in seedlings transferred from 25°C to 15°C differed from the kinetics exhibited by seedlings transferred from
25°C to 28°C. At 15°C, measurable curvature began 40–50 min after the blue light (BL) pulse and no straightening was evident
within 150 min after the BL pulse. Seedlings transferred to 28°C exhibited kinetics of phototropism similar to the phototropic
response of plants maintained at 25°C except that straightening began slightly faster in the seedlings at 28°C. Based on these
results, it is concluded that changes in temperature conditions affect both the elongation rate of seedlings and a first positive
phototropism and that phototropic curvature and subsequent straightening are independently controlled.
In memory of Radomir Konjević (1 August 1946–22 July 2006), plant physiologist, teacher, mentor, and friend. 相似文献
5.
Acclimation of chlorophyll biosynthetic reactions to temperature stress in cucumber (Cucumis sativus L.) 总被引:1,自引:0,他引:1
The adaptive responses of the greening process of plants to temperature stress were studied in cucumber (Cucumis sativus L. cv. Poinsette) seedlings grown at ambient (25 °C), low (7 °C) and high (42 °C) temperatures. Plastids isolated from these
seedlings were incubated at different temperatures and the net syntheses of various tetrapyrroles were monitored. In plastids
isolated from control seedlings grown at 25 °C, the optimum temperature for synthesis of Mg-protoporphyrin IX monoester or
protochlorophyllide was 35 °C. Temperature maxima for Mg-protoporphyrin IX monoester and protochlorophyllide syntheses were
shifted to 30 °C in chill-stressed seedlings. The net synthesis of total tetrapyrroles was severely reduced in heat-stressed
seedlings and the optimum temperature for Mg-protoporphyrin IX monoester or protochlorophyllide synthesis shifted slightly
towards higher temperatures, i.e. a broader peak was observed. To further study the temperature acclimation of seedlings with
respect to the greening process, tetrapyrrole biosynthesis was monitored at 25 °C after pre-heating the plastids (28–70 °C)
isolated from control, chill- and heat-stressed seedlings. In comparison to 28 °C-pre-heated plastids the percent inhibition
of protochlorophyllide synthesis in 40 °C-pre-heated plastids was higher than for the control (25 °C-grown) in chill-stressed
seedlings and lower than for the control in heat-stressed seedlings. Maximum synthesis of total tetrapyrroles and protoporphyrin
IX was observed when chloroplasts were heated at 50 °C, which was probably due to heat-induced activation of the enzymes involved
in protoporphyrin IX synthesis. Prominent shoulders towards lower or higher temperatures were seen in chill-stressed or heat-stressed
seedlings, respectively. The shift in optimum temperature for tetrapyrrole biosynthesis in chill- and heat-stressed seedlings
was probably due to acclimation of membranes possibly undergoing desaturation or saturation of membrane lipids. Proteins synthesized
in response to temperature-stress may also play an important role in conferring stress-tolerance in plants.
Received: 8 October 1998 / Accepted: 19 November 1998 相似文献
6.
The objectives were to determine the influence of water activity (aw, 0.997–0.92) and temperature (10–37°C) and their interactions on conidial germination, mycelial growth and sporulation of
two strains of Stachybotrys chartarum in vitro on a potato dextrose medium. Studies were carried out by modifying the medium with glycerol and either spread plating
with conidia to evaluate germination and germ tube extension or centrally inoculating treatment media for measuring mycelial
growth rates and harvesting whole colonies for determining sporulation. Overall, germination of conidia was significantly
influenced by aw and temperature and was fastest at 0.997–0.98 aw between 15 and 30°C with complete germination within 24 h. Germ tube extension was found to be most rapid at similar aw levels and 25–30°C. Mycelial growth rates of both strains were optimal at 0.997 aw between 25 and 30°C, with very little growth at 37°C. Sporulation was optimum at 30°C at 0.997 aw. However, under drier conditions, this was optimum at 25°C. This shows that there are differences in the ranges of aw x temperature for germination and growth and for sporulation. This may help in understanding the role of this fungal species
in damp buildings and conditions under which immune-compromised patients may be at risk when exposed to such contaminants
in the indoor air environment. 相似文献
7.
Based on the meteorological data over a period of 4 years (1980–3), the macro-environment of BenCat Farm situated in the southern
part of Vietnam (27 m above mean sea-level, 11° N and 106° E) was categorized as a “monsoon tropical climate”, due to heavy
rainfall (annual mean 2028.96 mm) and about 32% wet days (annual mean 116.52 days) together with high air temperature (annual
mean daily temperature 28.58, max. 32.33 and min 24.85° C). April was the hottest (monthly mean >35°C) and January the coldest
month (monthly mean <22° C) of the year. The maximum number of wet days were during September and October (mean 18 days.month),
whereas the minimum number of wet days were during January and February (mean <1 day/month). The months of December and January
at Ben-Cat buffalo farm were categorized as the “comfortable (moderate-Dry) period” as the mean daily temperature was <27°
C, while the remaining 10 months of the Calender year (February–November) were categorized as the “hot period” (mean daily
temperature >27° C). On the basis of rainfall and the number of wet days, the hot period was further subdivided into a “hot-dry
period” (February–April, mean of 1.67 wet days/month and mean rainfall 19.43 mm/month) and a “hot-humid period” (May–November,
mean of 15.57 wet days/month and mean rainfall 276.28 mm/month). 相似文献
8.
Summary Wheat (Triticum aestivum L.) haploids and doubled haploids have been used in breeding programs and genetic studies. Wheat haploids and doubled haploids
via anther culture are usually produced by a multiple step culture procedure. We improved a wheat haploid and doubled haploid
production system via anther culture in which plants are produced from microspore-derived embryos using one medium and one
culture environment. In the improved protocol, tillers of donor plants were pretreated at 4°C for 1–2 wk before anthers were
plated on a modified 85D12 basal medium with phenylacetic acid (PAA) and zeatin and cultured at 30°C with a 12-h daylength
(43 μEs−1m−2) in an incubator. Microspore-derived embryos developed in 2–3 wk and the plants were produced 3–4 wk after anther plating.
In the improved system, as much as 53% of the anthers of Pavon 76 were responsive with multiple embryos. For plant regeneration,
as many as 22 green and 25 albino plants were produced from 100 anthers. Sixty-five green plants were grown to maturity and
32 (49%) plants were fertile and produced seeds (indicating spontaneous chromosome doubling) while 33 plants did not produce
seed. Of five Nebraska breeding lines tested using the protocol, NE96675 was very responsive and the other lines less so,
indicating that the protocol is genotype-dependent. 相似文献
9.
Hydromedion sparsutum is a locally abundant herbivorous beetle on the sub-Antarctic island of South Georgia, often living in close association
with the tussock grass Parodiochloa flabellata. Over a 4-day period in mid-summer when the air temperature varied from 0 to 20°C, the temperature in the leaf litter 5–10 cm
deep at the base of tussock plants (the microhabitat of H. sparsutum) was consistently within the range of 5–7.5°C. Experiments were carried out to assess the ability of H. sparsutum larvae collected from this thermally stable environment to acclimate when maintained at lower (0°C) and higher (15°C) temperatures.
The mean supercooling points (freezing temperature) of larvae collected in January and acclimated at 0°C for 3 and 6 weeks
and 15°C for 3 weeks were all within the range of −2.6 to −4.6°C. Larvae in all treatment groups were freeze tolerant. Acclimation
at 0°C significantly increased survival in a 15-min exposure at −8°C (from 27 to 96%) and −10°C (from 0 to 63%) compared with
the field-fresh and 15°C-treated larvae. Similarly, survival of 0°C-acclimated larvae in a 72-h exposure at −6°C increased
from 20 to 83%. Extending the acclimation period at 0°C to 6 weeks did not produce any further increase in cold tolerance.
The concentrations of glucose and trehalose in larval body fluids increased significantly with low temperature acclimation.
Larvae maintained at 15°C for 3 weeks (none survived for 6 weeks) were less able to survive 1-h exposures between 30 and 35°C
than the 0°C-treated samples. Whilst vegetation and snow cover are an effective buffer against low winter temperatures in
many polar insects, the inability of H. sparsutum larvae to acclimate or survive at 15°C suggests that protection against high summer temperatures is equally important for
this species.
Accepted: 2 August 1999 相似文献
10.
People adapt to thermal environments, such as the changing seasons, predominantly by controlling the amount of clothing insulation, usually in the form of the clothing that they wear. The aim of this study was to determine the actual daily clothing insulation on sedentary human subjects across the seasons. Thirteen females and seven males participated in experiments from January to December in a thermal chamber. Adjacent months were grouped in pairs to give six environmental conditions: (1) January/February = 5°C; (2) March/April = 14°C; (3) May/June = 25°C; (4) July/August = 29°C; (5) September/October = 23°C; (6) November/December = 8°C. Humidity(45 ± 5%) and air velocity(0.14 ± 0.01 m/s) were constant across all six experimental conditions. Participants put on their own clothing that allowed them to achieve thermal comfort for each air temperature, and sat for 60 min (1Met). The clothing insulation (clo) required by these participants had a significant relationship with air temperature: insulation was reduced as air temperature increased. The range of clothing insulation for each condition was 1.87–3.14 clo at 5°C(Jan/Feb), 1.62–2.63 clo at 14°C(Mar/Apr), 0.87–1.59 clo at 25°C(May/Jun), 0.4–1.01 clo at 29°C(Jul/Aug), 0.92–1.81 clo at 23°C (Sept/Oct), and 2.12–3.09 clo at 8°C(Nov/Dec) for females, and 1.84–2.90 clo at 5°C, 1.52–1.98 clo at 14°C, 1.04–1.23 clo at 25°C, 0.51–1.30 clo at 29°C, 0.82–1.45 clo at 23°C and 1.96–3.53 clo at 8°C for males. The hypothesis was that thermal insulation of free living clothing worn by sedentary Korean people would vary across seasons. For Korean people, a comfortable air temperature with clothing insulation of 1 clo was approximately 27°C. This is greater than the typical comfort temperature for 1 clo. It was also found that women clearly increased their clothing insulation level of their clothing as winter approached but did not decrease it by the same amount when spring came. 相似文献
11.
A phosphate solubilizing and antagonistic bacterial strain, isolated from a Western Ghat forest soil in Kerala province, India
(designated as NII-0906), showed cold tolerance and grew from 10 to 37°C (optimum temperature 30°C). It was a Gram-positive,
rod shaped, 0.8–1.6 μm in size, and exhibited tolerance to a wide pH range (5–12; optimum 7.0) and salt concentration up to
7% (w/v). The isolate showed maximum similarity with Exiguobacterium marinum TF-80T based on 16S rRNA analysis. It solubilized tricalcium phosphate under in vitro conditions. The phosphate solubilization was
estimated along a temperature range (5–40°C), and maximum activity (84.7 μg mL−1 day−1) was recorded at 30°C after 10 days of incubation. The phosphate solubilizing activity coincided with a concomitant decrease
in pH of the medium. The isolate also exhibited antifungal activity against phytopathogenic fungi in Petri dish assays and
produced siderophore and hydrogen cyanide. The strain’s plant growth promotion properties were demonstrated through a cowpea-based
bioassay under greenhouse conditions. The bacterial inoculation resulted in significant increment in plant root, stem and
as well as in plant biomass. Further, scanning electron microscopic study revealed the root colonization in cowpea. These
results could offer potential perspective for the strain to be used as plant growth-promoting rhizobacteria, which could be
used as an inoculant for regional crops. 相似文献
12.
D. Ste¸piński 《Biologia Plantarum》2003,47(3):333-339
Relative nuclear DNA contents in cortex parenchyma cells in root segments of 3- and 7-d-old soybean seedlings grown at 25
°C and in plants grown for 3 d at 25 °C, and then for 4 d at 10 °C, were determined with cytophotometry. Measurements revealed
that in each variant the cortex cell nuclei with DNA content between 2C and 8C were in all the examined segments and nuclei
with 8C – 16C DNA appeared in higher parts of roots. However, in chilled plant cells the number of 8C – 16C DNA nuclei was
very low. Therefore, chilling inhibited endoreplication in comparison with plants grown at 25 °C for 7 d, and even reduced
endopolyploidy level as compared to the initial seedlings, i.e. 3-d-old plants. DNA contents in root hairs grown at 25 °C (control) and in root hairs emerged at 10 °C were also determined.
In controls 4C – 8C DNA nuclei predominated while in chilled plants an additional population of 2C – 4C DNA appeared. Thus
a reduction of DNA synthesis was brought about by low temperature. The occurrence of an intermediate DNA contents besides
those with full endoreplication cycles suggests the possibility of differential DNA replication. This suggestion seems to
be supported by the lack of 3H-thymidine incorporation into root hair nuclei at the examined developmental stage both in control and chilled root hairs.
The same number, but larger, chromocentric lumps in polyploid cortex cell nuclei of higher root zones, in comparison to meristematic
nuclei, suggests that endoreduplication process occurred.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
13.
Erica andevalensis Cabezudo & Rivera is a threatened edaphic endemic species of Andalusia (SW Spain). Under natural conditions, the plants produce
a very large number of small seeds (0.3–0.4 mm) but very few seedlings survive. Different treatments (high temperature, cold
pre-treatment, nitrogen salts, and gibberellic acid applications) were tested to assess germination patterns in different
populations and to determinate the most favorable conditions for germination. Gibberellic acid was provided in five different
concentrations from 0 to 400 ppm GA3, while nitrogen was applied as 10 mM of either KNO3 or NH4NO3. The effect of pH on germination was also tested. The species always showed a low germination rate (6.50–22%) that was not
stimulated either by 1 or 4 months in dry cold pre-treatment, nitrogen application, acid pH medium, or by high temperature
(80°C for 10 min); although gibberellic acid application (100–400 ppm) significantly enhanced germination. The highest percentage
of germination (41.6%) was achieved with a mean germination time to start germination (t
0) of 7.6 ± 0.54 days when the seeds were subjected to 400 ppm gibberellic acid treatment. The population origin did not have
a significant effect on germination percentage. 相似文献
14.
The effect of temperature on the development of immature stages of the predator Cheyletus malaccensis Oudemans, produced by either fertilized or virgin females, was studied at 17.5, 20, 25, 30, 32.5, and 35°C, 80 ± 5% relative
humidity, in complete darkness, and fed Tyrophagus putrescentiae (Schrank). The population maintained at 15°C failed to reproduce. The thermal data obtained were used for the estimation
of the thermal requirements (developmental thresholds, thermal constant, optimum temperature) of this predator by a linear
and nonlinear model (Logan type I model). Upper and lower developmental thresholds ranged between 37.4–37.8 and 11.6–12.0°C,
respectively. Optimum temperature for development was estimated at between 33.1 and 33.5°C. The thermal constant ranged between
238.1 and 312.5 degree-days. Based on the data of the total pre-imaginal period, immatures’ survival peaked at 25°C. Arrhenotokous
parthenogenesis (haplodiploidy) is confirmed in the species: virgin females always produce males, whereas fertilized females
give rise to offspring of both sexes. Survival of the immature stages and offspring sex ratio were not significantly influenced
by temperature. 相似文献
15.
Jing Wang Wei-wei Zhang Jin-ni Liu Yao-ling Cao Xiao-ting Bai Yue-sheng Gong Pei-lin Cen Ming-ming Yang 《Molecular biology reports》2010,37(7):3297-3302
An alkaline active xylanase, XynBYG, was purified from an alkaliphilic Bacillus pumilus BYG, which was newly isolated from paper mill effluent. It had an optimum pH of 8.0–9.0, and showed good stability after
incubated at pH 9.0 for 120 min. The optimum temperature for the activity was 50°C, and the enzyme retained below 55% of its
original activity for 30 min at 55°C. The gene coding for XynBYG consists of 687 bp and encodes 229 amino acids. Similarity
analysis indicated that XynBYG belong to family 11 glycosyl hydrolases. Site-directed mutagenesis was performed to replace
five sites (Tyr/Ser) to Arg/Glu and the results demonstrated that the optimum temperature of the mutant Y7 (S39R-T146E) increased
5°C and the half-life of inactivation (T1/2) at 60 and 65°C was 1 h and 25 min, respectively. Thus, it provides a potential
xylanase that can meet the harsh conditions in the industrial applications. 相似文献
16.
Taoka Y Nagano N Okita Y Izumida H Sugimoto S Hayashi M 《Marine biotechnology (New York, N.Y.)》2009,11(3):368-374
The growth, lipid content, and fatty acid composition of Aurantiochytrium sp. strain mh0186 at different temperatures were investigated. Strain mh0186 grew well at 15–30°C, but weakly at 10°C. The
biomass at 15–30°C was significantly higher than at 10 and 35°C, and the total lipid at 15–35°C was significantly higher than
that at 10°C. The amount of DHA in the total fatty acid was highest at 10°C and decreased in response to temperature increase.
The content of DHA (mg/g-dry cell weight) at 15–30°C were significantly higher than those at 35°C and those at 15–25°C were
significantly higher than those at 10 and 35°C. The DHA yield at 15–35°C was significantly higher than those at 10 and 35°C.
Unsaturation of fatty acid was regulated by temperature and was enhanced in response to temperature decrease. The ratio of
DHA to DPA varied at different temperatures. 相似文献
17.
C. J. Baxter N. Magan B. Lane H. G. Wildman 《Applied microbiology and biotechnology》1998,49(3):328-332
A Phoma sp., known to produce the pharmaceutically active metabolites squalestatin 1 (S1) and squalestatin 2 (S2), was cultured on
malt-extract/agar (MEA) over a range of water activities (a
w, 0.995–0.90) and temperatures (10–35 °C) to investigate the influence on growth and metabolite production. Use of the ionic
solute NaCl to adjust a
w resulted in significantly lower (P < 0.01) squalestatin yields than when the Phoma sp. was grown on MEA amended with the non-ionic solute glycerol. Water activity and temperature and their interactions were
highly significant factors (P < 0.001) affecting growth of the Phoma sp., with optimum conditions of 0.998–0.980 a
w and 25 °C. Squalestatin production was similarly influenced by a
w, temperature, time and their interactions (P < 0.001). S1 and S2 production occurred over a narrower a
w and temperature range than growth, with a slightly lower optimum a
w range of 0.995–0.980 a
w. The optimum temperature for squalestatin production varied from 20 °C (S1) to 25 °C (S2) and yields of S2 were up to 1000
times lower than those of S1. The ratio of S1 and S2 produced by the Phoma sp. was influenced by a
w and temperature, with highest values at 0.99–0.98 a
w, and at 15 °C. Incubation times of 28 days gave highest yields of both S1 and S2. Up to 2000-fold increases in squalestatin
yields were measured at optimum environmental conditions, compared to the unmodified MEA. This indicates the need to consider
such factors in screening systems used to detect biologically active lead compounds produced by fungi.
Received: 2 June 1997 / Received last revision: 6 November 1997 / Accepted: 7 November 1997 相似文献
18.
Isolates ofStypocaulon scoparium Kütz. were collected from the Gulf of St. Lawrence, Canada and compared in culture to isolates collected from the Atlantic
and Mediterranean coasts of Europe. The Canadian isolates grew at temperatures ranging from −2° C up to 22° C, with maximum
rates of growth at 10–15° C; in trials lasting 3 months they survived the lowest temperatures but died at 22 or 25° C. In
contrast, for the European isolates, maximum growth occurred between 10 and 27° C, and they died only after several months
at 30 or 33° C. At the low end of the temperature range, European plants suffered damage or died at 5° C. Only the northernmost
isolate, from Brittany, could both survive at 0° C and remain undamaged at 5° C in short days. All European isolates died
at −2° C. Geographic distributions and the different thermal responses suggest that the eastern and western Atlantic populations
are two different entities, the European plants being possibly of Tethyan origin, and the Canadian plants being possibly of
north Pacific origin. The former would then have occupied the north Atlantic for thelongest time, which may partly explain
the occurrence of ecotypic variation among these isolates. 相似文献
19.
Bruce Vondracek Wayne A. Wurtsbaugh Joseph J. Cech 《Environmental Biology of Fishes》1988,21(1):45-57
The allocation of energy to growth and reproduction, in relation to temperature and food availability, was investigated in
laboratory experiments with the mosquitofish,Gambusia affinis. At constant temperature of 20, 25 and 30°C and ad libitum feeding, specific growth rates increased with increasing temperature
at 1.7, 3.1 and 3.4% dry mass day−1, respectively. Growth rates in a cycling temperature regime (20–30°C,
) were faster than in a 25°C constant temperature. As temperature increased from 20 to 30°C, mean age at first reproduction
decreased from 191 to 56 days and brood size and mass of offspring increased significantly. Interbrood interval was also temperature
dependent; estimates at 25 and 30°C for females >1000 mg were 22.6 and 18.6 days, respectively. Interbrood interval could
not be calculated at 20°C. Although fitness was highest at 30°C, females at 25°C invested a greater proportion of surplus
energy (growth and reproduction) to reproduction (38%) than at 20 (17%) or 30°C (36%) during the 32-week study. Fish at cooler
temperatures began reproduction at a smaller size.
Where rations were controlled at low, medium, and ad libitum levels, somatic and gonadal growth increased with increasing
temperatures and food availability. The proportion of energy invested in reproduction was highest at 25°C for each comparable
ration level. Calculated energy budgets indicated that over the 10-week study, 17–22% of the food energy was invested in growth,
0–7% in reproduction, and 75–83% in respiration and excretory losses, depending on feeding and temperature conditions. 相似文献
20.
Decline in skeletal growth of the coral Porites?lutea from the Andaman Sea, South Thailand between 1984 and 2005 总被引:1,自引:1,他引:0
Of the few studies that have examined in situ coral growth responses to recent climate change, none have done so in equatorial
waters subject to relatively high sea temperatures (annual mean >27°C). This study compared the growth rate of Porites lutea from eight sites at Phuket, South Thailand between two time periods (December 1984–November 1986 and December 2003–November
2005). There was a significant decrease in coral calcification (23.5%) and linear extension rates (19.4–23.4%) between the
two sampling periods at a number of sites, while skeletal bulk density remained unchanged. Over the last 46 years, sea temperatures
(SST) in the area have risen at a rate of 0.161°C per decade (current seasonal temperature range 28–30°C) and regression analysis
of coral growth data is consistent with a link between rising temperature and reduced linear extension in the order of 46–56%
for every 1°C rise in SST. The apparent sensitivity of linear extension in P. lutea to increased SST suggests that corals in this part of the Andaman Sea may already be subjected to temperatures beyond their
thermal optimum for skeletal growth.
Communicated by Environment Editor Prof. Rob van Woesik 相似文献