scholarly journals Supercooling and Cold-hardiness of Acclimated and Deacclimated Buds and Stems of Persian Walnut Cultivars and Selections

HortScience ◽  
2010 ◽  
Vol 45 (11) ◽  
pp. 1662-1667 ◽  
Author(s):  
Asadolah Aslani Aslamarz ◽  
Kourosh Vahdati ◽  
Majid Rahemi ◽  
Darab Hassani ◽  
Charles Leslie
Keyword(s):  
Thermal Analysis ◽  
Cold Hardiness ◽  
Tissue Injury ◽  
Field Observations ◽  
Persian Walnut ◽  
Severity Of Injury ◽  
Commercial Cultivars ◽  
Controlled Freezing ◽  
Tissue Browning ◽  
Stem Segments

To study the cold-hardiness of Persian walnut cultivars and selections, three methods were compared: 1) thermal analysis; 2) evaluation of tissue health after controlled freezing; and 3) field observations after a severe midwinter freeze. Stem segments and buds were collected from eight Persian walnut genotypes (four commercial cultivars and four promising Iranian selections). Thermal analysis was conducted using thermoelectric modules (TEM) to measure the high (HTE) and low (LTE) temperature exotherms produced when water and tissues freeze. TEM signals were recorded as the temperature of the samples was decreased at a rate of 2 °C/h. Tissue injury under controlled temperatures was evaluated using pre-chilled stem segments cooled at 2 °C/h to set temperatures ranging from –5 to –30 °C and then held at these temperatures for 16 h. Frozen samples were thawed and visually evaluated for severity of injury. Cold damage under field conditions was evaluated after an unusually severe winter freeze. Twigs from affected trees were removed in mid-February and in April and visually rated for extent of injury and ability to recover. The occurrence of LTEs was correlated with death of the tissues as assessed by tissue browning. Both the capacity to supercool and the cold-hardiness of cultivars and selections tested increased with accumulated seasonal chilling and decreased as they approached spring budbreak. Thermal analysis showed a tendency for buds and stems to exhibit multiple LTEs at peak dormancy. The cultivars and selections were classified into three groups based on their cold-hardiness: sensitive (‘Z30’ and ‘Serr’), semihardy (‘Z53’ and ‘Z67’), and hardy (‘Lara’, ‘Hartley’, ‘Z63’, and ‘Pedro’).

scholarly journals COLD HARDINESS OF RABBITEYE BLUEBERRY

HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 436e-436
Author(s):  
Frank B. Matta ◽  
Gena R. Silva ◽  
James M. Spiers
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Cold Acclimation ◽  
Electrolyte Leakage ◽  
Cold Hardiness ◽  
Tissue Injury ◽  
Test Results ◽  
Tissue Browning

Cold acclimation of `Tifblue' rabbiteye blueberry was determined using differential thermal analysis (DTA). Electrolyte leakage and tissue browning test results were correlated with DTA. DTA showed that three exotherms occurred: exotherm 1 (ET) associated with extracellular freezing, exotherm 2 (CT) associated with tissue injury, and exotherm 3 (LTE) not associated with tissue injury. Maximum hardiness (–20C) occurred in January. The LT50 measured by electrolyte leakage and tissue browning was about –17C and –15C, respectively. Acclimation began in November and deacclimation in mid-Feb. 1994.

scholarly journals 329 DIFFERENTIAL THERMAL ANALYSIS OF RABBITEYE BLUEBERRIES

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 477f-477
Author(s):  
Gena R. Hughes ◽  
Frank B. Matta
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Low Temperature ◽  
Cold Hardiness ◽  
Vaccinium Ashei ◽  
Tissue Browning

Acclimation and cold hardiness of blueberry buds (Vaccinium ashei cv. Tifblue) were evaluated using differential thermal analysis (DTA) and tissue browning. Buds exhibited a single exotherm at -7C October through December and at -11C January through April. LOW temperature exotherms (LTE) were not detected. Tissue browning test ratings indicated that ovary death occurred at -21C.

COLD-HARDINESS EVALUATION OF PERSIAN WALNUT BY THERMAL ANALYSIS AND FREEZING TECHNIQUE

2010 ◽  
pp. 269-272 ◽  
Author(s):  
A.A. Aslamarz ◽  
K. Vahdati ◽  
M. Rahemi ◽  
D. Hassani
Keyword(s):  
Thermal Analysis ◽  
Cold Hardiness ◽  
Persian Walnut

scholarly journals Cold Hardiness of Floral Buds in Three Southern Highbush Blueberry (Vaccinium coymbosum × V. Darrowi) Cultivars

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 898E-898
Author(s):  
Gena R. Silva ◽  
Frank B. Matta ◽  
James M. Spiers
Keyword(s):  
United States ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Cold Hardiness ◽  
Southeastern United States ◽  
Highbush Blueberry ◽  
Flower Buds ◽  
Southern Highbush ◽  
Spring Frosts ◽  
Tissue Browning

Late spring frosts are a major concern to blueberry growers in the southeastern United States. Cold hardiness of flower buds (stages 4 to 6) was evaluated in three southern highbush blueberry cultivars (`Cooper', `O'Neal', and `Gulfcoast'). Differential thermal analysis (DTA) and tissue browning tests revealed that the critical temperature and ovary damage occurred at –11C in `Cooper', –12C in `O'Neal', and –13C in `Gulfcoast'.

scholarly journals Pecan Cold Hardiness Determined by Differential Thermal Analysis

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 851E-851
Author(s):  
Frank B. Matta ◽  
Amin Kawatin
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Electrolyte Leakage ◽  
Cold Hardiness ◽  
Tissue Injury ◽  
Critical Temperatures ◽  
The Relationship ◽  
Tetrazolium Test

Our objectives were to 1) Determine acclimation and deacclimation patterns of buds and stems of four pecan cultivars in Mississippi and 2) to determine the relationship between cold hardiness, based on DTA, and tissue injury, based or viability tests. Stem critical temperatures for September showed that `Hughes' was slower in acclimating than `Jackson'. Maximum hardiness for all cultivars occurred in January, except for `Desirable', which reached maximum hardiness in December but started deacclimating in January. Deacclimation for the remaining cultivars started in February. Bud critical temperatures for September and October also show that `Hughes' was slower in acclimating compared to the remaining cultivars. Maximum bud hardiness for `Desirable' occurred in December, with the remaining cultivars reaching maximum hardiness in January. Bud deacclimation for all cultivars occurred in March. The LD50 for the tetrazolium and electrolyte leakage tests occurred at about –32 and –30C, respectively. In buds, LT50 for the tetrazolium test was –18C. The LT50 electrolyte leakage and browning test was –20C.

scholarly journals Effect of Primocane Suppression Date on `Marion' Trailing Blackberry. II. Cold Hardiness

1995 ◽  
Vol 120 (1) ◽  
pp. 25-27 ◽  
Author(s):  
Neil C. Bell ◽  
Bernadine C. Strik ◽  
Lloyd W. Martin
Keyword(s):  
Cold Hardiness ◽  
Room Temperature ◽  
Ground Level ◽  
Soluble Carbohydrates ◽  
Controlled Freezing ◽  
Tissue Browning

Primocanes of `Marion' trailing blackberry plants were suppressed by cutting them off at ground level in either late April, May, June, or July 1991 and 1992. An unsuppressed control was included in which primocanes were not cut. A single cane was removed from each replication of the five primocane suppression dates at monthly intervals from mid-November to mid-February 1991-92, and from mid-November to mid-January 1992-93. One-node samples were exposed to controlled freezing at temperatures of 4, -6, -9, -12, -15, and -18C in November through February. In December and January, the-6 temperature was replaced with-21C. After 5 days at room temperature following freezing, growing point, budbase, vascular, and pith tissues were evaluated for tissue browning on a 1 to 5 scale. The LT50 developed for each suppression date was compared to the control. July-suppressed plants were generally hardiest for all tissues. June-suppressed plants were somewhat less hardy than July-suppressed plants, while April-, May- and unsuppressed plants were comparable and least hardy. Cane tissues of July-suppressed and unsuppressed plants had a higher level of soluble carbohydrates than other suppression dates.

scholarly journals PECAN COLD HARDINESS DETERMINED BY DIFFERENTIAL THERMAL ANALYSIS

HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 437e-437
Author(s):  
Frank B. Matta ◽  
Amin Kawatin
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Electrolyte Leakage ◽  
Cold Hardiness ◽  
The Other ◽  
Critical Temperatures ◽  
Leakage Test ◽  
Tetrazolium Test ◽  
Tissue Browning

Stem critical temperatures for September showed that `Hughes' was later in acclimating than `Jackson'. Maximum hardiness for all cultivars occurred in January and deacclimation in February. Bud critical temperatures for September and October also showed that `Hughes' acclimated later than the other cultivars. Maximum hardiness for buds occurred in January and deacclimation in March. In December, the LT50 for the tetrazolium test, the electrolyte leakage test, and the tissue browning test were –18, –20, and –20C, respectively, as shown by differential thermal analysis of `Desirable'.

scholarly journals Primary Bud Hardiness of Four Genotypes of Grapes in Arkansas

1991 ◽  
Vol 116 (5) ◽  
pp. 835-837 ◽  
Author(s):  
Timothy F. Bourne ◽  
J.N. Moore ◽  
Milon F. George
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Cold Hardiness ◽  
Training System ◽  
The Other ◽  
Training Systems ◽  
Freeze Damage ◽  
Vitis Spp

Four interspecific grape hybrids (Vitis spp.) developed in Arkansas were evaluated for primary bud hardiness by differential thermal analysis. Buds from two locations were analyzed over 2 years for acclimation, midwinter hardiness, and deacclimation. In addition, effects of two training systems on cold hardiness of buds were evaluated in one location. The buds of the two genotypes with the greatest component of V. vinifera in their ancestry acclimated more slowly than did the other genotypes. Ultimate midwinter bud hardiness was greater in the genotypes possessing less V. vinifera than other parentage. No effect on cold hardiness due to training system was noted. No natural winter freeze damage was observed on any of the genotypes in the period of observation.

scholarly journals Freezing stress survival mechanisms in Vaccinium macrocarpon Ait. terminal buds

2020 ◽  
Vol 40 (7) ◽  
pp. 841-855
Author(s):  
Camilo Villouta ◽  
Beth Ann Workmaster ◽  
Jenny Bolivar-Medina ◽  
Smith Sinclair ◽  
Amaya Atucha
Keyword(s):  
Cold Hardiness ◽  
Liquid Water Content ◽  
Vaccinium Macrocarpon ◽  
Freezing Stress ◽  
Cold Temperatures ◽  
Woody Perennial ◽  
Stress Survival ◽  
Mri Scans ◽  
Terminal Buds ◽  
Controlled Freezing

Abstract Plants’ mechanisms for surviving freezing stresses are essential adaptations that allow their existence in environments with extreme winter temperatures. Although it is known that Vaccinium macrocarpon Ait. buds can acclimate in fall and survive very cold temperatures during the winter, the mechanism for survival of these buds is not known. The main objective of this study was to determine which of the two major mechanisms of freezing stress survival, namely, deep supercooling or freeze-induced dehydration, are employed by V. macrocarpon terminal buds. In the present study, no low-temperature exotherms (LTEs) were detected by differential thermal analysis. Furthermore, a gradual reduction of relative liquid water content in the inner portions of buds during magnetic resonance imaging (MRI) scans performed between 0 and −20 °C (where no damage was detected in controlled freezing tests (CFT)) indicates these buds may not deep supercool. The higher ice nucleation activity of outer bud scales and the appearance of large voids in this structure in early winter, in conjunction with the MRI observations, are evidence supportive of a freeze-induced dehydration process. In addition, the presence of tissue browning in acclimated buds as a result of freezing stress was only observed in CFT at temperatures below −20 °C, and this damage gradually increased as test temperatures decreased and at different rates depending on the bud structure. Ours is the first study to collect multiple lines of evidence to suggest that V. macrocarpon terminal buds survive long periods of freezing stress by freeze-induced dehydration. Our results provide a framework for future studies of cold hardiness dynamics for V. macrocarpon and other woody perennial species and for the screening of breeding populations for freezing stress tolerance traits.

scholarly journals F.01 Prognostic factors in adults with spinal cord injury without radiological abnormalities (SCIWORA): MRI study

2016 ◽  
Vol 43 (S2) ◽  
pp. S18-S19
Author(s):  
R Martinez-Perez ◽  
I Paredes ◽  
J Cotrina ◽  
S Pandey ◽  
A Lagares
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Prognostic Factors ◽  
Injury Severity ◽  
Tissue Injury ◽  
Soft Tissue Injury ◽  
Lesion Length ◽  
Initial Examination ◽  
Severity Of Injury ◽  
Cord Injury

Background: Spinal Cord Injury Without Radiological Abnormality (SCIWORA) is underreported and poorly recognized in adults. This entity is an important subtype of spinal cord injury (SCI) with relatively good outcomes. Despite this, few studies have been performed to determine specific imaging-related prognostic factors. Methods: A retrospective review of adult patients with cervical SCI admitted to two University hospitals from January 2000 to December 2010 was performed. Only patients with an MRI performed within 72 hours after trauma were included. All patients with bony injury or traumatic malalignment were excluded. Data gathered on the remaining patients included demographics, mechanism of injury, severity of SCI, long-term patient outcome, improvement in neurological condition and MRI results. Results: 49 patients selected. Patients with extramedullary hemorrhage showed worse neurological status at initial examination. Disruption of either the anterior longitudinal ligament or ligamentum flavum was associated with worse outcomes at initial examination and at 1-year follow up. Lesion length was also significantly associated with outcomes at 1 year evaluation and initial evaluation. Conclusions: Early MRI has an important prognostic value in patients suffering SCIWORA. Lesion length is a powerful predictor of outcome. Soft tissue injury and spinal cord changes play a role in the severity of injury as well as the ability to recover.

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