The effect of temperature on cold hardening of Loliutn perenne seedlings

1980 ◽  
Vol 95 (1) ◽  
pp. 77-81 ◽  
Author(s):  
M. P. Fuller ◽  
C. F. Eagles
Keyword(s):  
Lolium Perenne ◽  
Low Temperatures ◽  
Cold Hardiness ◽  
Leaf Growth ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Screening Techniques ◽  
Temperature Regimes ◽  
Different Temperatures ◽  
Cool Night

SummaryThe variation in hardening responses under different temperature regimes for three cultivars of Lolium perenne L. is described. The relative cold hardiness of the cultivars was modified by different temperatures during hardening. A threshold temperature existed above which hardening did not occur, but this temperature varied between cultivars.Although continuous low temperatures (2 °C) favoured hardening, hardening also occurred under warm day and cool night conditions (15:2 °C) where cultivars showed contrasting hardiness responses in daylengths of 16, 12 and 8 h. Under some of these conditions both leaf growth and hardiness were possible.The significance of these results is discussed in terms of the development of screening techniques and breeding objectives.

The effect of temperature on the consumption of fat during pupal development inGlossina.

1960 ◽  
Vol 51 (3) ◽  
pp. 583-598 ◽  
Author(s):  
E. Bursell
Keyword(s):  
Low Temperatures ◽  
Fat Content ◽  
Effect Of Temperature ◽  
Tsetse Flies ◽  
Optimum Temperature ◽  
Glossina Morsitans ◽  
Pupal Development ◽  
Pupal Period ◽  
Fat Consumption ◽  
Different Temperatures

The size-specific fat content of tsetse flies recently emerged from their puparia was determined and by comparison with the size-specific fat content of newly deposited larvae an estimate was obtained of the consumption of fat during pupal development. Experiments withGlossina morsitansWestw. were carried out at a number of different temperatures and it was found that the amount of fat consumed was least at temperatures between 22 and 24°C.Knowing the duration of the pupal period at different temperatures, the rate of fat consumption could be calculated and the logarithm of this rate was found to be linearly related to temperature. The occurrence of an optimum temperature in respect of fat consumption thus reflects the fact that at high temperatures the rate of fat consumption is greatly increased without a corresponding reduction in the duration of the pupal period, whereas at low temperatures the pupal period is very greatly lengthened without a corresponding decrease in the rate of fat consumption.

The effect of temperature on the oxygen consumption of isolated human umbilical arteries

1970 ◽  
Vol 48 (6) ◽  
pp. 377-381 ◽  
Author(s):  
Carol Colthart ◽  
Margot R. Roach
Keyword(s):  
Oxygen Consumption ◽  
Low Temperatures ◽  
Arrhenius Plot ◽  
Post Partum ◽  
Effect Of Temperature ◽  
Metabolic Processes ◽  
Different Temperatures ◽  
High And Low Temperatures ◽  
Umbilical Arteries

The oxygen consumption [Formula: see text] of isolated segments of 40 human umbilical arteries was measured at different temperatures from 5 °C to 37 °C with a modified Fenn microrespirometer. The values varied from 8 μl/g per h at 8 °C to 70 μl/g per h at 37 °C. The Arrhenius plot was nonlinear, and the Q10 varied from 0.11 (30–40 °C) to 1.8 (20–30 °C) and 7.1 (10–20 °C). This suggests that the metabolic processes may be different at high and low temperatures. The results were consistent for at least 5 h post partum, and did not seem to vary from one segment of the cord to another.

Effect of Temperature and Safeners on Glutathione Levels and Glutathione S-Transferase Activity in Maize

1991 ◽  
Vol 46 (9-10) ◽  
pp. 856-860 ◽  
Author(s):  
Daniel L. Kunkel ◽  
John C. Steffens ◽  
Robin R. Bellinder
Keyword(s):  
Low Temperatures ◽  
Herbicide Tolerance ◽  
Effect Of Temperature ◽  
Transferase Activity ◽  
Glutathione S Transferase ◽  
Different Temperatures ◽  
Maize Plants ◽  
Incubation Temperatures ◽  
Gst Activity

Abstract Studies were conducted to determine the biochemical aspects of chloroacetamide injury to maize and the mechanism by which safeners maintain herbicide tolerance, even at reduced temperatures. The objectives of these studies were threefold: one, determine whether gluta­thione (GSH) content varies in maize plants grown at three different temperatures in safener-treated and non-treated plants; two, determine whether glutathione S-transferase (GST) activ­ity varies in plants grown at different temperatures; and three, determine if GSH activity is sensitive to low temperatures in vitro. The herbicide safeners CGA -154281 [4-(dichloroacetyl)-3,4-dihydro-3-methyl-2 H-1 ,4-benzoxazine] and dichlormid [2,2-dichloro-N,N-di-2-propenylacetamide] were used with metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-n-(2-methoxy-1-methyl)acetamide] or acetochlor [2-chloro-N-(ethoxymethyl)-N-2-ethyl-6-methylphenyl)-acetamide], respectively, to determine the mechanisms of maize tolerance. CGA -154281 signifi­cantly increased GSH levels in maize seedlings grown at 27 °C compared to non-safened seed­lings, however significant differences were not seen at 17 or 37 °C. Dichlormid increased GSH levels by 1.6-fold at all growth temperatures. Both CGA -154281 and dichlormid increased GST activity significantly at all growth temperatures. The safener-induced GST activity was main­tained at in vitro incubation temperatures of 5 and 15 °C for acetochlor and metolachlor, re­spectively. In contrast, GST activity from non-safened tissue was essentially absent at these temperatures. Therefore, greater GST activity following safener treatment may result in higher levels of herbicide metabolism, even at low temperatures.

scholarly journals The effect of temperature on the development and reproduction of Busseola fusca (Lepidoptera: Noctuidae)

2016 ◽  
Vol 107 (1) ◽  
pp. 39-48 ◽  
Author(s):  
J. Glatz ◽  
H. du Plessis ◽  
J. Van den Berg
Keyword(s):  
Larval Development ◽  
Busseola Fusca ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Single Male ◽  
Temperature Regimes ◽  
Threshold Temperatures ◽  
Thermal Constants ◽  
Lower Temperature ◽  
The Impact

AbstractThe effect of temperature on the reproduction and development of Busseola fusca was studied under laboratory conditions. Single male–female pairs were confined to oviposition chambers kept at 15, 20, 26 and 30 ± 1°C and a 14L:10D photoperiod. Data on reproduction parameters were captured daily. Oviposition occurred at all the mentioned temperatures but no fertility was recorded at 30°C. The total number of eggs laid per female moth was between 300 and 400 and the optimum temperature for oviposition and fertility was between 20 and 26°C. Larval development was studied at five different temperature regimes, i.e. 15, 18, 20, 26 and 30 ± 1°C and a 14L:10D photoperiod. The most favourable temperature as well as the upper threshold temperature for larval development was between 26 and 30°C. Total development period was 152.6–52.6 days, respectively, at 15°C, and 26–30°C. The thermal constants for B. fusca was 99.50, 536.48, 246.25 and 893.66°D and lower temperature thresholds were 10.36, 8.14, 8.99 and 8.84°C, for completion of the egg, larval, pupal and egg-to-adult stages, respectively. Results on the thermal constants and lower and upper threshold temperatures of B. fusca can be used to predict the impact of climate change on the distribution and population growth of this pest.

Effect of temperature on the growth of wheat. II. "Grass-clump" dwarfs and dwarf varieties

1969 ◽  
Vol 47 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Yun-te Yao ◽  
David T. Canvin
Keyword(s):  
Continuous Light ◽  
Normal Growth ◽  
Temperature Treatment ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Essentially Normal ◽  
Normal Varieties ◽  
Temperature Regimes ◽  
Temperature Requirements ◽  
Seed Yields

Six F1 "grass-clump" hybrids, two "grass-clump" selections, three normal varieties (Timstein, Redman, and Federation), and three dwarf varieties (Sonora 64, CB 151, and Norin 10) were grown in growth cabinets under 1200 ft-c of continuous light at various temperatures. The normal and dwarf varieties grew tallest at 16 °C and produced maximum shoot and seed yields at 16–19 °C.The Marquillo × Timstein "grass-clump" dwarf selection (F6) tillered extensively in temperature regimes that included 16 h of 16 °C in 24 h or 16 h of 21 °C and 8 h of 16 °C. Fertile tillers were produced in all temperature regimes except 16 °C. Growth at temperatures above 21 °C was essentially normal. The Redman × Federation "grass-clump" dwarf selection (F6) produced many tillers, but no fertile tillers when grown in a temperature regime that included 16 h of 16 °C. Fertile tillers were produced in all other temperature regimes, but extensive tillering was observed if the temperature treatment included 8 h of 16 °C. Completely normal growth was observed at temperatures above 26 °C.The six F1 "grass-clump" hybrids elongated and produced seed when grown at 30 °C.All "grass-clump" dwarf hybrids and dwarf selections investigated to date differ from normal varieties of wheat in that they are sterile dwarfs when grown at low temperature but grow essentially "normal" above a threshold temperature. Depending on the particular hybrid or selection the required temperature may be 21, 26, or 30 °C. In general, if the precise temperature requirements are not known, it appears probable that elongation and seed production by "grass-clump" dwarf can be induced by growing them under continuous light at 26 to 30 °C.

Stand establishment in processing carrots – Effects of various temperature regimes on germination and the role of salicylates in promoting germination at low temperatures

2002 ◽  
Vol 82 (2) ◽  
pp. 443-450 ◽  
Author(s):  
Lada R. Rajasekaran ◽  
Azure Stiles, Claude ◽  
D. Caldwell
Keyword(s):  
Low Temperature ◽  
Acetylsalicylic Acid ◽  
Low Temperatures ◽  
Seed Treatment ◽  
Germination Percentage ◽  
Threshold Temperature ◽  
Critical Threshold ◽  
Temperature Regimes ◽  
Carrot Seed

The effects of various temperature regimes on carrot seed germination and the possibility of hastening germination at a low temperature using salicylates were studied. Seeds were incubated at various temperatures viz., 25, 20, 15, 10, 5 and 2°C. Salicylates such as, 2,6-dihydoxybenzoic acid (DHBA), acetylsalicylic acid (ASA), salicylic acid (SA) were supplied at 0, 1, 10, 100 and 1000 mg L-1 continually to the seeds incubated at 25 and 5°C until germination. Data on germination percentage were collected, and vigor value was calculated. Incubating seeds at various low temperature regimes significantly and proportionately reduced germination percentage and vigor value. The highest cumulative germination and vigor value was observed at 25°C. Critical threshold temperature for germination (GT50) was 5°C. Seed treatment using salicylates hastened germination at 5°C. 2,6-dihydoxybenzoic acid 1, ASA 100 and SA 1 mg L-1 all were effective in hastening germination at 5°C. Among all the salicylates, ASA 100 mg L-1 was the most effective in advancing germination at 5°C. Salicylates at the highest concentration of 1000 mg L-1 inhibited germination significantly both at 25 and 5°C. Key words: Acetylsalicylic acid, carrot, 2,6-dihydoxybenzoic acid, germination percentage, rate of germination, salicylates, SA, temperature, thermogenesis, vigor value

scholarly journals Kinetics of winter deacclimation in response to temperature determines dormancy status and explains budbreak in differentVitisspecies

2018 ◽  
Author(s):  
Alisson P. Kovaleski ◽  
Bruce I. Reisch ◽  
Jason P. Londo
Keyword(s):  
Cold Hardiness ◽  
Effect Of Temperature ◽  
Good Prediction ◽  
Chilling Requirement ◽  
Perennial Plant ◽  
Different Temperatures ◽  
Winter Cold ◽  
Response To Temperature ◽  
The Relationship ◽  
Kinetics Of

2.AbstractBud dormancy and cold hardiness are critical adaptations for surviving winter cold stress for temperate perennial plant species, with shifting temperature-based responses during the winter. The objective of this study was to uncover the relationship between dormancy transition (chilling requirement) and temperature on the loss of cold hardiness and budbreak. Dormant cuttings ofVitis vinifera,V. aestivalis,V. amurensis, andV. ripariawere examined to determine the relationship between chilling requirement and temperature on rate of deacclimation (kdeacc). Differential thermal analysis was used to determinekdeaccusing mean low temperature exotherms. Effect of chill was evaluated as the deacclimation potential (ψdeacc), which was the change inkdeaccdue to chill accumulation. Budbreak was also evaluated in fully chilled buds at different temperatures. Results indicate that ψdeaccvaries dependent on dormancy state, following a logarithmic response to chill accumulation. The effect of temperature onkdeaccwas exponential at low and logarithmic at high temperatures. The combination of ψdeaccandkdeaccresulted in good prediction of deacclimation. Budbreak phenology was also explained by differences inkdeacc. Deacclimation rates can be used as a quantitative determinant of dormancy transition and budbreak, and to refine models predicting effects of climate change.

Effect of temperature on pupa development and sexual maturity of laboratory Anastrepha obliqua adults

2011 ◽  
Vol 101 (5) ◽  
pp. 565-571 ◽  
Author(s):  
R. Telles-Romero ◽  
J. Toledo ◽  
E. Hernández ◽  
J.L. Quintero-Fong ◽  
L. Cruz-López
Keyword(s):  
Low Temperatures ◽  
Sexual Maturity ◽  
Pupal Stage ◽  
Lower Proportion ◽  
Effect Of Temperature ◽  
Gas Chromatography Mass Spectrometry ◽  
Unknown Compound ◽  
Anastrepha Obliqua ◽  
Different Temperatures ◽  
Male Volatiles

AbstractThe effect of four temperatures (18, 20, 25 and 30°C) on pupa development and sexual maturity of Anastrepha obliqua adults was investigated under laboratory conditions. The results showed that the duration of the pupal stage decreased with an increase in temperature (29, 25, 13 and 12 days, respectively), and maintaining the pupae at 18°C and 20°C results in a low percentage of pupation, pupa weight loss and lesser flying ability. However, it significantly favored sexual behavior, a higher proportion of sexual calls and matings. While enhanced pupa development was observed at a temperature of 30°C, adults had low sexual efficiency, as well as a lower proportion of calls and matings. Gas chromatography-mass spectrometry (GC-MS) analysis of male volatiles showed that the amount of (Z,E)-α-farnesene did not vary among males from pupae reared at different temperatures; however, less (E,E)-α-farnesene was emitted by males obtain from pupa reared at 30°C. Male flies kept at 30°C during their larval stage had more (Z)-3-nonenol and, also, an unknown compound was detected. The fecundity of the females was higher at low temperatures. Regarding fertility, no significant differences were found between temperatures. The optimal temperature on pupa development was 25°C when males displayed ideal attributes for rearing purposes.

If you work with phenology, you work with bud cold hardiness dynamics

2021 ◽  
Author(s):  
Al Kovaleski ◽  
Jason Londo
Keyword(s):  
Low Temperatures ◽  
Cold Hardiness ◽  
Temperature Response ◽  
Initiation Point ◽  
The Past ◽  
Heritable Trait ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Impacts Of Climate Change ◽  
Phenological Phases

<p>Budbreak is one of the most observed and studied phenological phases in perennial plants. Historically, two effects of temperature are used to model budbreak: the accumulation of heat units (forcing); and the accumulation of time spent at low temperatures (chilling). These two effects have a well-established negative correlation: the more chilling, the less forcing is required to reach budbreak. However, prediction of budbreak remains a challenge, as even artificial warming experiments do not match changes in observed budbreak timing during the past few decades of climate warming. The cold hardiness of buds is, however, largely ignored in estimations of timing to budbreak. Cold hardiness level fluctuates throughout the winter as temperatures change, constantly altering the initiation point of deacclimation. During budbreak assays, cold hardiness loss is extremely slow (low deacclimation rate) at low chill accumulation, and increases to a maximum at high chill accumulation. By standardizing deacclimation rates for each species based on the maximum observed, a deacclimation potential describes dormancy fulfillment. Our studies show that deacclimation rates vary at different temperatures demonstrating the effect of forcing is non-linear. We show that the concept of variable chilling requirements for satisfying dormancy (high chill vs. low chill) is largely erroneous and instead these phenotypes reflect previously unmeasured differences between species or genotypes regarding the interaction between cold hardiness state and deacclimation potential. Our studies show that forcing responses (maximum rates of deacclimation) are normally distributed within a species, and are a heritable trait. Three effects of temperature are thus necessary to describe contemporary phenology patterns as well as predict future impacts of climate change: the accumulation of chill, the forcing temperature response, and the cold hardiness of buds.</p>

Effect of temperature on cold dehardening of Lolium perenne L. seedlings

1981 ◽  
Vol 96 (1) ◽  
pp. 55-59 ◽  
Author(s):  
M. P. Fuller ◽  
C. F. Eagles
Keyword(s):  
Lolium Perenne ◽  
Effect Of Temperature ◽  
Lolium Perenne L ◽  
Temperature Regimes ◽  
Threshold Temperatures ◽  
Alternating Temperature ◽  
Daily Period

SUMMARYCold dehardening responses of seedlings of three cultivars of Lolium perenne L. (Premo, S.23 and Grasslands Ruanui) were studied in different temperature regimes following hardening at 2 °C. Seedlings of the three cultivars dehardened rapidly at 15 °C after partial hardening for 4 days, whereas there was a lag before dehardening occurred in seedlings of Premo and S.23 which were hardened for 28 days. At 10 °C dehardening did not occur in Premo and S.23 and occurred only slowly in Grasslands Ruanui. Alternating temperature regimes of 15 °C(day): 2 °C (night) gave increased levels of hardiness when the daily period of exposure to 15 °C was 8 h but only maintained the level of hardiness when it was extended to 16 h.A tentative scheme of threshold temperatures for hardening and dehardening is proposed.

Sign in / Sign up

Export Citation Format

Share Document