共查询到20条相似文献,搜索用时 31 毫秒
1.
Summary The infection of root hairs and nodulation ofT. subterraneum L. cv. Cranmore byRhizobium trifolii strain TA1 was extremely sensitive to root temperature. Within the range 11°–19°C infection was progressively delayed as
root temperature decreased but at 7°C no root hairs were infected by 40 days. At 7°C lateral root formation was stimulated
in the root zone where nodules formed at 19°C. 相似文献
2.
Merja Suutari 《Archives of microbiology》1995,164(3):212-216
The effect of growth temperature on the lipid fatty acid composition was studied over a temperature range from 35 to 10°
C with 5° C intervals in four exponentially growing fungi: Aspergillus niger, Neurospora crassa, Penicillium chrysogenum, and Trichoderma reesei. Fatty acid unsaturation increased in A. niger, P. chrysogenum, and T. reesei when the temperature was lowered to 20–15, 20, and 26–20° C, respectively. In A. niger and T. reesei, this was due to the increase in linolenic acid content. In P. chrysogenum, the linolenic acid content increased concomitantly with a more pronounced decrease in the less-unsaturated fatty acid, oleic
acid, and in palmitic and linoleic acids; consequently, the fatty acid content decreased as the temperature was lowered to
20° C. In T. reesei, when the growth temperature was reduced below 26–20° C, fatty acid unsaturation decreased since the mycelial linolenic acid
content decreased. In A. niger and P. chrysogenum, the mycelial fatty acid content increased greatly at temperatures below 20–15° C. In contrast, in N. crassa, fatty acid unsaturation was nearly temperature-independent, although palmitic and linoleic acid contents clearly decreased
when the temperature was lowered between 26 and 20° C; concomitantly, the growth rate decreased. Therefore, large differences
in the effects of growth temperature on mycelial fatty acids were observed among various fungal species. However, the similarities
found may indicate common regulatory mechanisms causing the responses.
Received: 1 March 1995 / Accepted: 8 May 1995 相似文献
3.
S. D. Kashenko 《Russian Journal of Marine Biology》2009,35(5):422-430
The combined effects of temperatures of 14, 17, 20, 22, and 25°C and salinities of 36–12‰ on embryos and larvae of the sand
dollar Scaphechinus mirabilis was studied. Embryonic development is the most sensitive stage in the early ontogenesis of S. mirabilis. It is completed at a temperature of 14–20°C in a salinity range of 36–24‰ and at temperature of 22°C to 26‰. The fertilization
proceeds in wider ranges of temperature and salinity. Among the swimming larvae, blastulae showed the greatest resistance
to variations of these environmental factors. All the larvae survived at a temperature of 14–22°C and a salinity of 36–20‰,
and more than 70% of them at 18‰. The pluteus I is the most vulnerable stage; probably this is related to the formation of
the larval skeleton and transition to phytoplankton feeding. The survival of larvae at the age of 20 days was 100% at 14–22°
C and a salinity of 36–24‰, most of them survived at 14–20°C and a salinity 18‰. The temperature 25 ° C is the most damaging
for early development of S. mirabilis. The duration of development of that species lasts 28.5–29 days at 20°C and a salinity of 32.2–32.6‰. At 20 and 22°C, the
larvae settled and completed metamorphosis more quickly if sand from the parental habitat was present. The larvae did not
settle during the experiment (14 days) at 14 ° C and in the absence of sand. 相似文献
4.
Studies were carried out under controlled laboratory conditions to evaluate the seedling growth capacities of chickpea (Cicer arietinum L.) varieties Pusa 209 and H208 at constant temperatures of 15, 20, 25 and 28°C (±0.5°C) and of pigeonpea (Cajanus cajan L.) variety Prabhat at 20 and 28°C (±0.5°C). Seedling growth at any given time was found to depend on ‘a’, the growth at
no impedance, and ‘b’, the impedance growth factori.e., decrease in growth with increase in impedance, and on temperature. The optimum temperature for chickpea was found to be
in the range of 20 to 24°C for better seedling growth characteristics, whereas for pigeonpea, 28°C was found to be more congenial
than 20°C. Chickpea varieties differed in their response to temperature.
Part of the M. Sc. thesis of first author submitted to the Indian Agricultural Research Institute, New Delhi-110012, India. 相似文献
5.
D. T. Booth 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1998,168(5):399-404
Incubation temperature and the amount of water taken up by eggs from the substrate during incubation affects hatchling size
and morphology in many oviparous reptiles. The Brisbane river turtle Emydura signata lays hard-shelled eggs and hatchling mass was unaffected by the amount of water gained or lost during incubation. Constant
temperature incubation of eggs at 24 °C, 26 °C, 28 °C and 31 °C had no effect on hatchling mass, yolk-free hatchling mass,
residual yolk mass, carapace length, carapace width, plastron length or plastron width. However, hatchlings incubated at 26 °C
and 28 °C had wider heads than hatchlings incubated at 24 °C and 31 °C. Incubation period varied inversely with incubation
temperature, while the rate of increase in oxygen consumption during the first part of incubation and the peak rate of oxygen
consumption varied directly with incubation temperature. The total amount of oxygen consumed during development and hatchling
production cost was significantly greater at 24 °C than at 26 °C, 28 °C and 31 °C. Hatchling mass and dimensions and total
embryonic energy expenditure was directly proportional to initial egg mass.
Accepted: 18 March 1998 相似文献
6.
Shamseldin A 《Biotechnology letters》2007,29(1):37-44
Soil acidity and high temperature contribute to the failure of nodulation in the common bean. It is therefore urgent to select
strains with a high competitive ability under these stress conditions. Two Egyptian Rhizobium etli strains, EBRI 2 and EBRI 26, were examined against Rhizobium tropici CIAT 899G labeled with the gus (β-glucuronidase) reporter gene. EBRI 2 and EBRI 26 were less competitive than CIAT 899G under acid conditions with both
the Egyptian cultivar Giza 3 and the Colombian cultivar Rab 39. However, EBRI 2 and EBRI 26 gave higher nodule occupancy (78%
and 62.5, respectively) than the nodule occupancy (18.5% and 35%) obtained by CIAT 899G at 35°C with cultivar Giza 3. Soil
acidity (pH 5.8) was less detrimental to the nodule occupancy of EBRI 2 than EBRI 26 when they tested in competition with
CIAT 899G. 相似文献
7.
T. A. Lie 《Plant and Soil》1971,35(1):117-127
Summary An outline is given of the possibility selecting Rhizobium strains capable of performing a relatively good symbiosis with
leguminous plants, growing under stress conditions. A Rhizobium strain capable of nodulating pea plants in acid soils is described.
A pea cultivar, resistant to the majority of Rhizobium strains when growing at 20°C, is found to require a short period of
a higher temperature for successful nodulation. The effect of non-photosynthetic light and its possible significance under
natural conditions is discussed. 相似文献
8.
Summary An experiment was conducted in controlled temperature water baths to compare the response of rice plant of variety Taichung
(Native) 1 to cyclic soil temperature regime of 32°C/20°C and constant soil temperature regime of 26°C. These temperature
regimes are reported to be highly favourable for rice growth and therefore selected for comparison.
The plants growing at 32°C/20°C showed some superiority over those growing at 26°C in respect of root growth and tiller development.
The grain yield at 32°C/20°C was higher which resulted from larger number of tillers and panicles than at 26°C, although the
difference in other yield characteristics was not appreciable. NPK content of grains, straw and roots did not vary appreciably
between 32°C/20°C and 26°C but the total uptake of these nutrients varied because of the difference in total dry matter production.
The results suggest that the development of rice plants, particularly in reproductive phase, is practically as good at 26°C
as at 32°C/20°C and there seems to be no sufficient ground for generalising the phenomenon of diurnal thermoperiodicity for
rice plants. 相似文献
9.
Josef Elster Peter Degma Ľubomír Kováčik Lucia Valentová Katarína Šramková Antonio Batista Pereira 《Biologia》2008,63(6):843-851
The freezing and desiccation tolerance of 12 Klebsormidium strains, isolated from various habitats (aeroterrestrial, terrestrial, and hydro-terrestrial) from distinct geographical
regions (Antarctic — South Shetlands, King George Island, Arctic — Ellesmere Island, Svalbard, Central Europe — Slovakia)
were studied. Each strain was exposed to several freezing (−4°C, −40°C, −196°C) and desiccation (+4°C and + 20°C) regimes,
simulating both natural and semi-natural freeze-thaw and desiccation cycles. The level of resistance (or the survival capacity)
was evaluated by chlorophyll a content, viability, and chlorophyll fluorescence evaluations. No statistical differences (Kruskal-Wallis tests) between strains
originating from different regions were observed. All strains tested were highly resistant to both freezing and desiccation
injuries. Freezing down to −196°C was the most harmful regime for all studied strains. Freezing at −4°C did not influence
the survival of studied strains. Further, freezing down to −40°C (at a speed of 4°C/min) was not fatal for most of the strains.
RDA analysis showed that certain Antarctic and Arctic strains did not survive desiccation at +4°C; however, freezing at −40°C,
as well as desiccation at +20°C was not fatal to them. On the other hand, other strains from the Antarctic, the Arctic, and
Central Europe (Slovakia) survived desiccation at temperatures of +4°C, and freezing down to −40°C. It appears that species
of Klebsormidium which occupy an environment where both seasonal and diurnal variations of water availability prevail, are well adapted to
freezing and desiccation injuries. Freezing and desiccation tolerance is not species-specific nor is the resilience only found
in polar strains as it is also a feature of temperate strains.
Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia.
This paper is dedicated to the memory of the late Dr. Bohuslav Fott (1908–1976), Professor of Botany at the Charles University
in Prague, to mark the centenary of his birth. 相似文献
10.
Lower induction temperature and polyoxyethylene sorbitan monolaurate (Tween-20) were successfully used to inhibit the aggregation
of recombinant human consensus interferon-α mutant (cIFN) during Pichia pastoris fermentation. When the induction temperature was decreased from 30 to 20°C, the cIFN secreted into the medium was in the form
of monomers instead of aggregates. The maximum specific activity at 20°C was 4.04 times as high as that at 30°C. There was
no obvious effect on the cell growth at 20°C, but the total protein level was decreased. Similar inhibition effect on cIFN
aggregation was observed when 0.2 g l−1 Tween-20 was added during induction. Furthermore, there was a synergistic effect found between induction temperature and
Tween-20 on the inhibition of cIFN aggregation. The maximum specific activity with Tween-20 at 20°C was 19.9-fold higher than
that without Tween-20 at 30°C. 相似文献
11.
《Plant and Soil》1971,35(1):129-137
Summary Strains of clover rhizobia were isolated from northern Scandinavia (68–70° N.lat.) and, for comparison, also from some places
in southern Scandinavia (S. of 63° N.lat.). Pure cultures were used for studies of 1) bacterial growth in liquid culture,
2) nodulation of host plants, and 3) nitrogenase activity, as measured by the acetylene reduction technique, of the host-bacterium
association. The tests were performed both at 10°C and 20°C.
In all these respects, the isolates from the subarctic region showed on an average better adaptation to low temperature than
the isolates from more southern areas. At 10°C, the former grew faster, nodulated their host plants somewhat earlier and showed
a more vigorous acetylene reduction than the latter. At 20°C no significant differences were observed between isolates of
different geographical origin.
An adaptation of Rhizobium to a cold climate and a short growing season might be useful for practical purposes, because soil
temperatures are usually low at sowing-time in large areas of the temperate zones. 相似文献
12.
M. Eriksson G. Dalhammar A.-K. Borg-Karlson 《Applied microbiology and biotechnology》1999,51(4):532-535
A hydrocarbon mixture containing p-xylene, naphthalene, Br-naphthalene and straight aliphatic hydrocarbons (C14 to C17) was aerobically degraded without lag phase by a natural uncontaminated potting soil at 20 °C and 6 °C. Starting concentrations
were approximately 46 ppm for the aromatic and 13 ppm for the aliphatic compounds. All aliphatic hydrocarbons were degraded
within 5 days at 20 °C, to levels below detection (ppb levels) but only down to 10% of initial concentration at 6 °C. Naphthalene
was degraded within 12 days at 20 °C and unaffected at 6 °C. At 20 °C p-xylene was degraded within 20 days, but no degradation occurred at 6 °C. Br-naphthalene was only removed down to 30% of initial
concentration at 20 °C, with no significant effect at 6 °C. The biodegradation was monitored with head space solid-phase microextraction
and gas chromatography–mass spectrometry.
Received: 5 October 1998 / Received revision: 4 December 1998 / Accepted: 5 December 1998 相似文献
13.
Dimorphic seeds of Atriplex prostrata were removed from cold dry storage monthly over a one year period to test for fluctuations in seed dormancy and germination
rate. For each seed type, four replicates of 25 seeds were exposed to four alternating night/day temperature regimes mimicking
seasonal fluctuations in Ohio: 5/15 °C; 5/25 °C; 15/25 °C and 20/35 °C with a corresponding 12-h photoperiod (20 μmol m−2 s−1; 400 – 700 nm). We found a significant three-way interaction of seed size, temperature and month for both percent germination
and the rate of germination. Large seeds showed the greatest germination at the 20/35 °C and 5/25 °C temperature regimes and
small seeds at the 5/25 °C regime. Large seeds had greater germination at all temperatures as compared to small seeds. Large
seeds had the fastest germination rates at 20/35 °C followed by 5/25 °C whereas small seeds had the fastest rates at 5/25
°C followed by 20/35 °C.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
The marcoalga Ulva pertusa was cultured under (20 ± 2)°C, (20 ± 4)°C, (20 ± 6)°C, (20 ± 8)°C and (20 ± 10)°C circadian rhythms of fluctuating temperature
conditions, and constant temperature of 20°C was used as the control. The growth rate of macroalga at (20 ± 2)°C, (20 ± 4)°C
and (20 ± 6)°C were significantly higher than that at constant temperature of 20°C, while growth rate at (20 ± 8)°C and (20
± 10)°C were significantly lower than that at constant temperature of 20°C. The growth rate of macroalga was a quadratic function
of the thermal amplitude. Such a growth model can be described by G = β
0 + β
1(TA) + β
2(TA)2, where G represents the relative growth rate, TA is thermal amplitude in degree Celsius, β
0 is the intercept on the G axis, and β
1 and β
2 are the regression coefficients. The optimal thermal amplitude for the growth of thallus at mean temperature of 20°C was
estimated to be ± 3.69°C. Analysis of biochemical composition at the final stages of thaulls growth revealed that diel fluctuating
temperature caused various influences (P < 0.05). The content of chlorophyll, protein and total solute carbohydrate at (20 ± 2)°C and (20 ± 4)°C were slightly higher
than those at constant temperature of 20°C, however no statistically significant differences were found among them (P > 0.05). While osmolytes (total solute carbohydrate and free proline) at (20 ± 10)°C were significantly higher than that at
20°C (P < 0.05). Therefore, more chlorophyll and carbohydrate production might account for the enhancement in the growth of macroalga
at the diel fluctuating temperatures in the present study.
Handling editor: S. M. Thomaz 相似文献
15.
Summary Red clover Rhizobium strains, isolated from different locations between latitudes 60° and 63°30′ N in Finland, were tested
for their adaptation to low temperatures. 31 strains were tested for growth at 5°C, 10°C, 15°C and 18°C in pure culture. No
strain grew at 5°C. At the other temperatures there were differences between the strains, but the same strains grew fast at
all temperatures. Ten strains were investigated for nodulation and acetylene reduction in phytotrons in two different climates,
one simulating the growing season in southern and the other in northern Finland. There were differences between the strains
in their ability to nodulate their host plant, and northern strains showed higher nitrogenase activity than southern strains
in the cold climate. 相似文献
16.
Yuan L. Wang Frederick P. Binkowski Sergei I. Doroshov 《Environmental Biology of Fishes》1985,14(1):43-50
Synopsis The effect of constant incubation temperatures (between 10°C and 26°C) on the developmental rates was found to fit a similar
exponential relationship in both the lake and white sturgeon embryos and larvae. Although the lake sturgeon had an overall
slower rate of development than the white sturgeon, no statistically significant difference was detected in the slopes of
the exponential equations describing the effect of temperature on developmental rate. The effect of these incubation temperatures
on embryonic survival also did not differ between these two species. Both species exhibited optimal survival between 14–17°
C and incipient mortalities occurred at 20°C. Temperatures above 20°C were lethal for white sturgeon embryos. No effect of
low incubation temperature on survival was evident from this study. A comparison of these North American species with Eurasian
acipenserids suggests that all the sturgeon that have been examined exhibit a similar influence of incubation temperature
on developmental rate. 相似文献
17.
C. L. Yntema 《Journal of morphology》1981,167(3):297-304
Eggs of Chelydra serpentina were incubated at 30°C and 26°C. In addition, incubation was done at 20°C during the temperature-sensitive period for sex determination. Incubation at 20°C and 30°C resulted in females; incubation at 26°C resulted in males in 99% of the cases. The average gonadal length was less in the males. The average length of the 20°C ovaries did not vary significantly from that of the 30°C ovaries. The condition of the oviducts was correlated with histology of the gonads in hatchlings and in 3-month-old animals. When at least one of the oviducts was obvious and intact, ovaries were present. If the oviducts were absent or interrupted, testes were present. Histological characteristics of the gonads resulting from the three incubation temperatures are described. In the 26°C testes, cellular infiltrations occurred frequently. The ovaries of 20°C hatchlings tended to have a less developed germinal epithelium than that of the 30°C animals. Also, epithelial cysts occurred frequently in the 20°C ovaries. The incidence of follicles at 3 months was not differential. 相似文献
18.
J. R. DUNLAP 《The Annals of applied biology》1988,112(1):187-194
The rate and final germination of four muskmelon cultivars (Cucumis melo) were examined in response to incubation temperatures of 20, 26 and 32°C. Germination was also characterised at 26°C pr 32°C over a range of water potentials from 0 to - 1000 kPa achieved with solutions of polyethylene glycol. The germination of one cultivar, TAM-Uvalde, was consistently slower at 20°C than at 26°C or 32°C. The other three cultivars, Perlita, TAM-Dew and Greenflesh, were inhibited by incubation at 32°C. However, the germination responses of cvs Perlita, TAM-Dew and Greenflesh at 26°C or 32°C improved as water potentials were reduced from 0 to – 200 or – 400 kPa. Cv. TAM-Uvalde was extremely sensitive to water stress and failed to germinate at water potentials below – 600 kPa when incubated at 26°C. The inhibition of germination at low water potentials was partially reversed in all cultivars by increasing the incubation temperature from 26°C to 32°C. It is suggested that the inhibition of germination at 0 kPa (distilled water) was due to a seed coat-mediated barrier to oxygen that could be reversed by removal of the seed coat or exposure to an oxygen-enriched atmosphere. 相似文献
19.
Exposure to 1,500 μg/ml of hydrogen peroxide (H2O2) for 60 min at 13°C was found to be injurious to rainbow trout eggs. On the other hand, the concentration which effectively
inhibited pathogenic fungi in vitro was substantially less than this toxic dosage; specifically, 500 μg/ml for 60 min at 20°C
to inhibit the zoosporic stage and 1,000 μg/ml for 60 min at 20°C to inhibit the vegetative stage. From in vivo tests, treatment
with 1,000 μg/ml of H2O2 for 60 min at 13°C was found to be the most effective procedure to control fungal infection and increase the hatching rate
of rainbow trout eggs. 相似文献
20.
Melzner F Bock C Pörtner HO 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2006,176(7):607-621
Earlier work found cuttlefish (Sepia officinalis) ventilatory muscle tissue to progressively switch to an anaerobic mode of energy production at critical temperatures (T
c) of 7.0 and 26.8°C. These findings suggested that oxygen availability limits thermal tolerance. The present study was designed to elucidate whether it is the ventilatory apparatus that sets critical temperature thresholds during acute thermal stress. Routine metabolic rate (rmr) rose exponentially between 11 and 23°C, while below (8°C) and above (26°C) this temperature range, rmr was significantly depressed. Ventilation frequency (f
V) and mean mantle cavity pressure (MMP) followed an exponential relationship within the entire investigated temperature range (8–26°C). Oxygen extraction from the ventilatory current (EO2) decreased in a sigmoidal fashion with temperature, falling from > 90% at 8°C to 32% at 26°C. Consequently, ventilatory minute volume (MVV) increased by a factor of 20 from 7 to 150% body weight min−1 in the same temperature interval. Increases in MMP and MVV resulted in ventilatory muscle power output (P
out) increasing by a factor of > 80 from 0.03 to 2.4 mW kg−1 animal. Nonetheless, costs for ventilatory mechanics remain below 1.5% rmr in the natural thermal window of the population (English Channel, 9–17°C), owing to very low MMPs of < 0.05 kPa driving the ventilatory stream, and may maximally rise to 8.6% rmr at 26°C. Model calculations suggest that the ventilatory system can maintain high arterial PO2 values of > 14 kPa over the entire temperature interval. We therefore conclude that the cuttlefish ventilation system is probably not limiting oxygen transfer during acute thermal stress. Depression of rmr, well before critical temperatures are being reached, is likely caused by circulatory capacity limitations and not by fatigue of ventilatory muscle fibres. 相似文献