scholarly journals Tomato Seedling Growth, Earliness, Yield, and Quality following Pretransplant Nutritional Conditioning and Low Temperatures

1991 ◽  
Vol 116 (3) ◽  
pp. 421-425 ◽  
Author(s):  
Regina R. Melton ◽  
Robert J. Dufault
Keyword(s):  
Low Temperature ◽  
Seedling Growth ◽  
Low Temperatures ◽  
Temperature Treatment ◽  
Tomato Seedling ◽  
Tomato Seedlings ◽  
Low Temperature Treatment ◽  
Yield And Quality ◽  
Temperature Exposure ◽  
Low Temperature Exposure

`Sunny' tomato (Lycopersicon esculentum Mill.) seedlings were pretransplant nutritionally conditioned (PNC) in 1988 and 1989 with factorial combinations of N from 100 to 300 mg·liter-1 and P from 10 to 70 mg·liter-1. In 1988, all conditioned seedlings were exposed to 12 hours of 2C for eight consecutive nights before transplanting. In 1989, half of the conditioned plants were exposed to a low-temperature treatment of 8 days with 12-hour nights at 2C and 12-hour days in a warm greenhouse (19C/26C, night/day). In both years, as N PNC increased to 200 mg·liter-1, seedling growth increased. Increasing P PNC from 10 to 40 mg·liter-1 increased seedling growth, but only in 1988. In both years, P PNC did not affect yields. Low-temperature exposure in 1989 decreased seedling growth in comparison to those held in a warm greenhouse (19C/26C, day/night). In 1988, first harvest yields were not affected by N PNC; however, in 1989, as N increased to 200 mg·liter-1, early yields increased. In 1988, total yields increased wit h N PNC from 100 to 200 mg·liter-1 and in 1989 with N at 50 to 100 mg·liter-1 with no further increases from 100 to 200 mg·liter-1. Low-temperature exposure had no effect on earliness, yield, or quality. A PNC regime combining at least 200 mg N/liter and up to 10 mg P/liter should be used to nutritionally condition `Sunny' tomato seedlings to enhance yield.

Effects of cyst components and low temperature exposure of Heterodera glycines eggs on juvenile hatching in vitro

Nematology ◽  
2011 ◽  
Vol 13 (7) ◽  
pp. 837-844 ◽  
Author(s):  
Edward P. Masler ◽  
Stephen T. Rogers
Keyword(s):  
Low Temperature ◽  
Heterodera Glycines ◽  
Temperature Treatment ◽  
Early Embryo ◽  
Residual Effects ◽  
Low Temperature Treatment ◽  
Affected Relative ◽  
Temperature Exposure ◽  
Low Temperature Exposure

AbstractThe effects of low temperature treatment of Heterodera glycines eggs and the interaction of this treatment with egg condition and cyst influences were examined in vitro. Exposure of eggs to 5°C for 1 week followed by a return to normal culture temperature resulted in a 25-33% reduction in hatch after 2 weeks at 28°C but there was no effect on the timing of hatch. Hatch from encysted eggs was 40% lower than from free eggs at 2 weeks, and hatch from low temperature-encysted eggs was more than 60% lower during the same period. Encystment also altered the timing of hatch relative to free eggs from the same cohort. Hatch from free eggs in the presence of cyst contents was accelerated relative to free eggs without cyst contents, but the total cumulative percent hatch was not increased. Reduction in hatch as a result of low temperature treatment was significant only if the treatment was applied prior to the first juvenile stage (J1). J1 were not affected relative to the hatch of second-stage juveniles (J2). However, the effect of low temperature on earlier stages was not detected until development ceased at early J1 and later J1. Also, low temperature treatment affected the apparent locomotion of some newly hatched J2; 16-fold more J2 from treated eggs were retained on 30 μm pore sieves than those from control eggs. The depression of hatch by low temperature egg treatment was apparently the result of the residual effects on early embryo stages, leading to arrest of development prior to J2.

scholarly journals Chilling Affects Flowering of Fall-bearing Red Raspberries

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 800A-800
Author(s):  
F. Takeda
Keyword(s):  
Low Temperature ◽  
Temperature Treatment ◽  
Flower Bud ◽  
Low Temperature Treatment ◽  
Temperature Exposure ◽  
Low Temperature Exposure ◽  
Chilling Hours ◽  
Bud Initiation ◽  
Shoot Emergence ◽  
Flower Bud Development

Tissue-cultured raspberry plants are not exposed to low temperatures during the propagation phase, yet the primocane that grows from the crown will flower terminally after developing 20 to 25 nodes. We studied the effect of duration of chilling (hours) (CH) on days to flower (DTF) in primocanes arising from root suckers of previously cropped fall-bearing `Heritage' and `'Summit' raspberries. Growth of `Heritage' plants with 0 or low CH was either short with rosetted leaves or indeterminate. Plants with 0 CH remained vegetative for >240 days, while plants with >750 CH flowered in <4 months when the primocane had 25 to 30 nodes. These results suggested that low-temperature exposure prior to shoot emergence was necessary for flower bud initiation in `Heritage' red raspberry. In contrast, all `Summit' flowered; DTF ranged from 120 days for 0 CH plants to <70 days for plants with 1000 CH. Low-temperature treatment affected flower bud development. Plants with 0 CH developed 15 flowering laterals, while plants with >750 CH had 25 flowering laterals. Although `Summit' needs no CH to flower, low temperature treatments definitely accelerated DTF and increased the number of fruiting laterals.

scholarly journals Is cold the new hot in sudden unexpected death in epilepsy? Effect of low temperature on heart rate of rats with epilepsy

2008 ◽  
Vol 66 (4) ◽  
pp. 848-852 ◽  
Author(s):  
Eliza Y.F. Sonoda ◽  
Diego B. Colugnati ◽  
Carla A. Scorza ◽  
Ricardo M. Arida ◽  
Aline P. Pansani ◽  
...  
Keyword(s):  
Risk Factors ◽  
Heart Rate ◽  
Low Temperature ◽  
Low Temperatures ◽  
Refractory Epilepsy ◽  
Sudden Unexpected Death ◽  
Unexpected Death ◽  
Temperature Exposure ◽  
Low Temperature Exposure ◽  
Related Mortality

Sudden unexpected death in epilepsy (SUDEP) is the commonest cause of seizure-related mortality in people with refractory epilepsy. Several risk factors for SUDEP are described; however, the importance of including low temperatures as risk factor for SUDEP was never explored. Based on this, the aim of this study was to evaluate the heart rate of rats with epilepsy during low temperature exposure. Our results showed that low temperature clearly increased the heart rate of rats with epilepsy. Taken together, we concluded that exposure to low temperatures could be considered important risk factors from cardiovascular abnormalities and hence sudden cardiac death in epilepsy.

INTERACTION OF RED AND FAR-RED RADIATIONS WITH THE VERNALIZATION PROCESS IN WINTER RYE

1965 ◽  
Vol 43 (1) ◽  
pp. 161-170 ◽  
Author(s):  
D. J. C. Friend
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
Temperature Treatment ◽  
Leaf Number ◽  
Winter Rye ◽  
Promoting Effect ◽  
Low Temperature Treatment ◽  
Phytochrome System ◽  
Red Radiation

Flowering of winter rye was advanced and the final leaf number reduced by red radiation (ca. 660 mμ) given to grain germinated at low temperatures for 4, 6, 8, or 9 weeks, and by far-red radiation (ca. 740 mμ) given during 3 weeks' low temperature treatment. Radiation was without effect on flowering when given during low temperature treatment continued until the grain was fully vernalized, when given during low temperature treatment of grain of spring rye, when given to grain of spring or winter rye maintained at 15 °C, and when given during thermal de-vernalization of winter rye.It is concluded that the phytochrome system is not involved in the flower-promoting effect of low temperature (vernalization) but that radiation given during low temperature treatment of germinating grain may enhance the stabilization of the vernalized condition.

An Analysis of Cell Freezing and Dehydration

1970 ◽  
Vol 92 (3) ◽  
pp. 393-398 ◽  
Author(s):  
G. R. Ling ◽  
C. L. Tien
Keyword(s):  
Differential Equation ◽  
Low Temperature ◽  
Cooling Rate ◽  
Low Temperatures ◽  
Living Cells ◽  
Cell Parameters ◽  
Theoretical Predictions ◽  
Cell Dehydration ◽  
Temperature Exposure ◽  
Low Temperature Exposure

A quantitative picture of the effect of low-temperature exposure on the survival of living cells is presented through discussion of solutions to a differential equation relating the volume of intracellular water to the temperature, the cooling rate, and various cell parameters. It is found that for a given cell, a single parameter which depends on the cooling rate governs the behavior of the cell when it is exposed to low temperatures. The analysis develops relationships between solutions to the differential equation and the phenomena affecting cell survival, namely, intracellular freezing and cell dehydration. Theoretical predictions are found to agree well with existing experimental observations.

scholarly journals Differences in lipid homeostasis and membrane lipid unsaturation confer differential tolerance to low temperatures in two Cycas species

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yanling Zheng ◽  
Yongqiong Yang ◽  
Meng Wang ◽  
Shijun Hu ◽  
Jianrong Wu ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Lipid Metabolism ◽  
Low Temperature ◽  
Low Temperatures ◽  
Photosynthetic Activity ◽  
Membrane Lipids ◽  
Chlorophyll Fluorescence Parameters ◽  
Fluorescence Parameters ◽  
Temperature Exposure ◽  
Low Temperature Exposure

Abstract Background C. panzhihuaensis is more tolerant to freezing than C. bifida but the mechanisms underlying the different freezing tolerance are unclear. Photosynthesis is one of the most temperature-sensitive processes. Lipids play important roles in membrane structure, signal transduction and energy storage, which are closely related to the stress responses of plants. In this study, the chlorophyll fluorescence parameters and lipid profiles of the two species were characterized to explore the changes in photosynthetic activity and lipid metabolism following low-temperature exposure and subsequent recovery. Results Photosynthetic activity significantly decreased in C. bifida with the decrease of temperatures and reached zero after recovery. Photosynthetic activity, however, was little affected in C. panzhihuaensis. The lipid composition of C. bifida was more affected by cold and freezing treatments than C. panzhihuaensis. Compared with the control, the proportions of all the lipid categories recovered to the original level in C. panzhihuaensis, but the proportions of most lipid categories changed significantly in C. bifida after 3 d of recovery. In particular, the glycerophospholipids and prenol lipids degraded severely during the recovery period of C. bifida. Changes in acyl chain length and double bond index (DBI) occurred in more lipid classes immediately after low-temperature exposure in C. panzhihuaensis compare with those in C. bifida. DBI of the total main membrane lipids of C. panzhihuaensis was significantly higher than that of C. bifida following all temperature treatments. Conclusions The results of chlorophyll fluorescence parameters confirmed that the freezing tolerance of C. panzhihuaensis was greater than that of C. bifida. The lipid metabolism of the two species had differential responses to low temperatures. The homeostasis and plastic adjustment of lipid metabolism and the higher level of DBI of the main membrane lipids may contribute to the greater tolerance of C. panzhihuaensis to low temperatures.

Induced bolting and anthesis in sugar beet and the effect of selection of physiological types

1946 ◽  
Vol 36 (3) ◽  
pp. 167-183 ◽  
Author(s):  
G. D. H. Bell
Keyword(s):  
Low Temperature ◽  
Sugar Beet ◽  
Low Temperatures ◽  
Continuous Light ◽  
Light Treatment ◽  
Seedling Stage ◽  
Temperature Exposure ◽  
Different Strains ◽  
Low Temperature Exposure ◽  
Selection Of

1. The effect of low-temperature and continuous-light treatment of seedlings of certain sugar beet strains in the isolation of distinct physiological types is described. The progenies of individual plants and bulk samples of different anthesis dates show some difference in the proportions of early and late plants, when these progenies are similarly exposed to low temperatures and continuous light in the seedling.2. Different treatments of progenies in relation to light treatment in the seedling stage result in distinct behaviour with regard to anthesis date and the number of plants reaching the stage of anthesis.3. The comparative resistance to bolting from a field sowing of seed obtained from plants which ripened seed after continuous light treatment of the seedlings is noted. This was so in spite of the fact that only 66% of the plants had reached anthesis as a result of the treatment, and the seed was obtained from the most rapidly bolting plants.4. Light and low temperature exposure of seedlings is effective in two different strains for isolating bolting-resistant types as measured directly from the seed of these bolting-resistant plants and selected progenies from these plants. Differences in the field germination and establishment from very early sowings were discernible in the progenies.

scholarly journals Duration of Low Temperature Exposure Affects Egg Hatching of the Colorado Potato Beetle and Emergence of Overwintering Adults

Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 609
Author(s):  
Jianghua Liao ◽  
Juan Liu ◽  
Zhijian Guan ◽  
Chao Li
Keyword(s):  
Low Temperature ◽  
Colorado Potato Beetle ◽  
Treatment Time ◽  
Early Summer ◽  
Short Term ◽  
Egg Survival ◽  
Egg Hatching ◽  
Potato Beetle ◽  
Temperature Exposure ◽  
Low Temperature Exposure

The Colorado potato beetle is a serious pest of Solanaceae in China. In early summer, cold spells in later spring may occur for brief periods in the field environmental conditions, and temperatures often deviate far below the normal temperature for short periods, such as sudden short-term low temperature, may affect the development of Colorado potato beetle eggs. This paper studies the effects of low temperature stress at 8 °C for 0 d, 1 d, 3 d, 5 d, 7 d, and 10 d on the development of Colorado potato beetle eggs. Our results show that egg survival is significantly affected by short-term low temperature exposure. The percentage of eggs hatched is significantly affected by different treatment times (p = 0.000)—the percentage of eggs hatched decreases with increased treatment time, and Colorado potato beetles will extend the wintering time of their soil to resist the effects of lower temperatures. Thus, exposure of Colorado potato beetles to a short-term low temperature affects their emergence and population growth; this study could provide information for the occurrence, monitoring, and early warning of Colorado potato beetle during short-term temperature.

Sign in / Sign up

Export Citation Format

Share Document