scholarly journals Freezing Tolerance of Avocado Leaves

HortScience ◽  
1992 ◽  
Vol 27 (4) ◽  
pp. 341-343 ◽  
Author(s):  
M.A. McKellar ◽  
D.W. Buchanan ◽  
Dewayne L. Ingram ◽  
C.W. Campbell
Keyword(s):  
Freezing Tolerance ◽  
Leaf Tissue ◽  
Freezing Temperature ◽  
Temperature Limit ◽  
Persea Americana ◽  
Ice Formation ◽  
Visual Appearance ◽  
Detached Leaves ◽  
Time Of Year ◽  
Lower Temperature

Freezing tolerance and the lethal freezing temperature were determined for detached leaves of avocado (Persea americana Mill.) by either electrolyte leakage or visual appearance of browning. Leaves from field-grown trees of `Gainesville', `Booth8', and `Winter Mexican' in both Gainesville and Homestead, Fla., were evaluated. All cultivars in both locations survived ice formation in their tissue. Leaf tissue had a temperature limit (lethal freeze temperature) at and below which the tissue died. The lethal freezing temperature varied from -5.1 to -9.3C, depending on time of year and location. The lethal freeze temperature for a cultivar decreased over the fall and winter as temperatures decreased. Leaves of `Booth-8' and Winter Mexican' decreased 2.5 and 1.5C, respectively, in Homestead from 13 Nov. 1982 to 5 Feb. 1983. The plants growing at the lower temperature location (Gainesville) had lower lethal freeze temperatures. Leaves of `Gainesville' had a lethal freeze temperature of - 9.3C from trees at Gainesville and - 7.8C from trees at Homestead.

Saline Growth Conditions Favour Supercooling and Increase the Freezing Tolerance of Leaves of Barley and Wheat

1992 ◽  
Vol 47 (9-10) ◽  
pp. 695-700 ◽  
Author(s):  
Michael Bender ◽  
Ulrich Heber ◽  
Karl-Josef Dietz
Keyword(s):  
Salt Stress ◽  
Freezing Tolerance ◽  
Growth Conditions ◽  
Ice Nucleation ◽  
Ice Formation ◽  
Freezing And Thawing ◽  
Subzero Temperatures ◽  
Cellular Dehydration ◽  
Detached Leaves ◽  
Leaf Survival

When young plants of barley and wheat grown in hydroponic culture were subjected to salt stress, their freezing tolerance increased with increasing severity of salt stress. Detached leaves from salt-stressed plants also exhibited an increased ability to supercool. Avoidance of ice formation permitted leaf survival at subzero temperatures which were no longer tolerated when ice nucleation resulted in extracellular freezing. The increased freezing tolerance under salt stress is attributed to osmotic adjustment of the plants. Increased cellular solute concentrations decrease the extent of cellular dehydration at freezing temperatures, thereby decreasing mechanical and chemical stresses on biomembranes during freezing and thawing.

Effect of Irradiation of the Extraction Mixture with 30% TBP in ISOPAR-M on the Lower Temperature Limit of Flame Propagation

2020 ◽  
Vol 62 (6) ◽  
pp. 723-729
Author(s):  
A. V. Rodin ◽  
I. V. Skvortsov ◽  
E. V. Belova ◽  
K. N. Dvoeglazov ◽  
B. F. Myasoedov
Keyword(s):  
Flame Propagation ◽  
Temperature Limit ◽  
Lower Temperature Limit ◽  
Lower Temperature ◽  
Extraction Mixture

scholarly journals Researches on the mixture limits of animal fats with liquid hydrocarbons for combustion at industrial level

2019 ◽  
Vol 112 ◽  
pp. 02001
Author(s):  
Dana Andreya Bondrea ◽  
Lucian Mihaescu ◽  
Gheorghe Lazaroiu ◽  
Ionel Pisa ◽  
Gabriel Negreanu
Keyword(s):  
Temperature Limit ◽  
Electric Heater ◽  
Liquid Hydrocarbons ◽  
Animal Fats ◽  
Lower Temperature Limit ◽  
Perfect Mixing ◽  
Efficient Combustion ◽  
Lower Temperature ◽  
Industrial Level ◽  
Experimental Researches

The experimental research has highlighted the variety of possibilities of combustion of animal fat from bovine and swine mixed with liquid hydrocarbons. Previous research has established that the upper limit for an efficient combustion was 30 %. For a perfect mixing, the lower temperature limit was set to 40 °C. In the fuel laboratory, at the department TMETF was determined the viscosity of the mixtures for different proportions. The values obtained for various concentrations and preheating temperatures were close to the values for liquid hydrocarbons. The experimental researches have studied the combustion of the mixture using a mechanically spraying burner with constant pressure between 14 and 18 bar. The aspiration of the mixture is done from a specially designed tank; this tank is equipped with an electric heater, in order to maintain the mixture at a constant temperature between 40 °C to 50 °C. After that, the burner heats again the mixture with an integrated heating device up to 75 °C. The burner is also equipped with an air blower, pump and a calibrated nozzle. The combustion resulted from the experimental boiler with a power rated to 55 kW were monitored with a thermal vision camera and an exhaust gas analyser. This research has demonstrated the viability of using this type of mixtures in energetic burning equipment designed for liquid hydrocarbons.

A lower temperature limit for the RIED effect

1994 ◽  
Vol 212-215 ◽  
pp. 1119-1122 ◽  
Author(s):  
A. Moroño ◽  
E.R. Hodgson
Keyword(s):  
Temperature Limit ◽  
Lower Temperature Limit ◽  
Lower Temperature

Effects of temperature cycling on the phase transition of water in gas-saturated sediments

2003 ◽  
Vol 81 (1-2) ◽  
pp. 343-350 ◽  
Author(s):  
E M Chuvilin ◽  
T Ebinuma ◽  
Y Kamata ◽  
T Uchida ◽  
S Takeya ◽  
...  
Keyword(s):  
Pore Space ◽  
Freezing Temperature ◽  
Temperature Cycling ◽  
Ice Formation ◽  
Porous Space ◽  
Water Ice ◽  
Temperature Cycles ◽  
Formation Conditions ◽  
Effects Of Temperature ◽  
Sandy Sediments

Experimental results on hydrate- and ice-formation conditions in the pores of sandy sediments that have undergone temperature cycles are presented. Thermodynamic parameters of gas hydrate and ice formation in porous space were determined for CH4 and CO2 saturated sandy sediments. The experiments indicate that temperature and freezing cycles affect the thermodynamics of hydrate and water–ice in gas-saturated sediments. Temperature cycles increased the hydrate accumulation in the pore space of sediments and reduce the freezing temperature of the remaining pore water. PACS Nos.: 91.60Hg, 92.40Sn

scholarly journals In vitro assays of Phytophthora agathidicida on kauri leaves suggest variability in pathogen virulence and host response

2018 ◽  
Vol 71 ◽  
pp. 285-288 ◽  
Author(s):  
Echo M. Herewini ◽  
Peter M. Scott ◽  
Nari M. Williams ◽  
Rosie E. Bradshaw
Keyword(s):  
Leaf Tissue ◽  
Host Susceptibility ◽  
In Vitro Assays ◽  
Disease Symptoms ◽  
Pathogen Virulence ◽  
Non Invasive ◽  
Detached Leaves ◽  
Invasive Method ◽  
Oomycete Pathogen

Phytophthora agathidicida is an aggressive soil-borne oomycete pathogen that kills New Zealand kauri trees (Agathis australis). When artificially inoculated, P. agathidicida causes lesions on leaves as well as roots, providing a non-invasive method for virulence screening. However, little is known about the extents to which the pathogen varies in virulence and kauri trees vary in disease susceptibility. Three isolates of P. agathidicida grown in culture were inoculated onto detached leaves from six kauri trees. Visible disease lesions were measured and the extent of asymptomatic leaf colonisation determined by culturing. All six trees were susceptible to P. agathidicida, but one showed higher susceptibility than the others. The pathogen also showed variability in virulence among isolates. Asymptomatic colonisation of leaf tissue was also found, suggesting a latent or biotrophic phase for the pathogen. Although further work is needed, the variability of both pathogen virulence and host susceptibility have important implications for management of kauri dieback. Furthermore, asymptomatic colonisation of kauri tissues suggests that P. agathidicida could be present outside of regions with visible disease symptoms.

scholarly journals 004 Root Application of Potassium Silicate Reduce Feeding Damage to Sargent Crabapple Leaf Tissues by Adult Japanese Beetles

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 441C-441
Author(s):  
A.M. Shirazi ◽  
F.D. Miller
Keyword(s):  
Plant Disease Resistance ◽  
Leaf Tissue ◽  
Potassium Silicate ◽  
Ion Leakage ◽  
Japanese Beetle ◽  
Detached Leaves ◽  
Leaf Tissues ◽  
Fall Webworm ◽  
Silicon Nutrition

Research on silicon nutrition has shown an increase in plant disease resistance to powdery mildew and pythium in some species, such as roses and cucumbers. However, the role of silicon for protecting plants from other stresses e.g., heat, drought, insects, etc., are not known. Two-year-old Sargent Crabapple Malus sargentii seedlings were subjected to 4 continuous days of 100 ml root application of potassium silicate at the rate of 0, 100, 200, and 400 ppm in Aug. 1998. After 3 days post-treatment, three detached leaves were placed in each of three petri dishes along with one adult female Japanese beetle (n = 3/concentrations) for 7 days. Potassium silicate at 100 ppm concentration significantly reduced percent leaf tissue eaten by adult Japanese beetles. There was not any statistical difference between control, 200, and 400 ppm application. The ion leakage of stem tissues of 100 and 200 ppm-treated plants were significantly lower than the control and 400 ppm. These lower ion leakage effects were also observed with red-osier dogwood stem tissues at 100 ppm. In a companion study fall webworm larvae were also exposed to the same above concentrations and treatments. There was not a significant effect of potassium pilicate on percent leaf tissue eaten by fall webworm larvae, suggesting that there may be differences between major groups of leaf-feeding insects. Leaf and root tissue analysis for Ca, K, Mg, Na, and Si will be reported.

scholarly journals Thermodynamic Equivalent between Noninteracting Bose and Fermi Gas in Metallic Carbon Nanotubes

2014 ◽  
Vol 24 (3S2) ◽  
Author(s):  
Chu Thuy Anh ◽  
Pham Thi Kim Hang ◽  
Pham Van Dien ◽  
Tran Thi Thanh Van ◽  
Nguyen Tri Lan ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Fermi Gas ◽  
Temperature Limit ◽  
Dimensional System ◽  
Electron Hole ◽  
Linear Dispersion ◽  
One Dimensional ◽  
High Temperature Limit ◽  
Ideal Gases ◽  
Lower Temperature

The equivalent between Bose and Fermi ideal gases is usually taken in high temperature limit only. Recently, there has been considerable interest in surprising thermodynamic ``equivalences'' between certain ideal Bose and spineless Fermi gas systems in lower temperature. In this work, we follow that idea to investigate the quasi one-dimensional system of metallic carbon nanotubes. Due to the linear dispersion law, the non-interacting Bose and Fermi gases in metallic carbon nanotubes are equivalent. This equivalence could be applied to the gas systems of exciton photon (Bose particles) and electron hole (Fermi particles) in metallic carbon nanotubes.

scholarly journals Mapping freezing tolerance QTL in alfalfa: based on indoor phenotyping

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Laxman Adhikari ◽  
Shiva O. Makaju ◽  
Orville M. Lindstrom ◽  
Ali M. Missaoui
Keyword(s):  
Cold Tolerance ◽  
Freezing Tolerance ◽  
Screening Method ◽  
Freezing Temperature ◽  
Indirect Selection ◽  
Selection Method ◽  
Snp Markers ◽  
Winter Hardiness ◽  
Close Relative ◽  
Percentage Survival

Abstract Background Winter freezing temperature impacts alfalfa (Medicago sativa L.) persistence and seasonal yield and can lead to the death of the plant. Understanding the genetic mechanisms of alfalfa freezing tolerance (FT) using high-throughput phenotyping and genotyping is crucial to select suitable germplasm and develop winter-hardy cultivars. Several clones of an alfalfa F1 mapping population (3010 x CW 1010) were tested for FT using a cold chamber. The population was genotyped with SNP markers identified using genotyping-by-sequencing (GBS) and the quantitative trait loci (QTL) associated with FT were mapped on the parent-specific linkage maps. The ultimate goal is to develop non-dormant and winter-hardy alfalfa cultivars that can produce extended growth in the areas where winters are often mild. Results Alfalfa FT screening method optimized in this experiment comprises three major steps: clone preparation, acclimation, and freezing test. Twenty clones of each genotype were tested, where 10 samples were treated with freezing temperature, and 10 were used as controls. A moderate positive correlation (r ~ 0.36, P < 0.01) was observed between indoor FT and field-based winter hardiness (WH), suggesting that the indoor FT test is a useful indirect selection method for winter hardiness of alfalfa germplasm. We detected a total of 20 QTL associated with four traits; nine for visual rating-based FT, five for percentage survival (PS), four for treated to control regrowth ratio (RR), and two for treated to control biomass ratio (BR). Some QTL positions overlapped with WH QTL reported previously, suggesting a genetic relationship between FT and WH. Some favorable QTL from the winter-hardy parent (3010) were from the potential genic region for a cold tolerance gene CBF. The BLAST alignment of a CBF sequence of M. truncatula, a close relative of alfalfa, against the alfalfa reference showed that the gene’s ortholog resides around 75 Mb on chromosome 6. Conclusions The indoor freezing tolerance selection method reported is useful for alfalfa breeders to accelerate breeding cycles through indirect selection. The QTL and associated markers add to the genomic resources for the research community and can be used in marker-assisted selection (MAS) for alfalfa cold tolerance improvement.

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