FREEZING SURVIVAL AND SUPERCOOLING IN PRIMARY AND SECONDARY BUDS OF Rubus spp.

1990 ◽  
Vol 70 (3) ◽  
pp. 893-904 ◽  
Author(s):  
M. R. WARMUND ◽  
M. F. GEORGE
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Low Temperature ◽  
Cold Hardiness ◽  
Rubus Idaeus ◽  
Freezing Injury ◽  
Red Raspberry ◽  
Viability Testing ◽  
Floral Buds ◽  
Floral Primordia

Primary and secondary buds from 11 blackberry (Rubus subgen. Rubus) and 10 red raspberry (Rubus idaeus) cultivars were subjected to viability testing to determine their relative hardiness from November 1987 through March 1988. Of the blackberries tested, Darrow floral buds were found to be the most hardy throughout dormancy. Forty-five percent of primordia in Darrow primary buds survived −33 °C in January. Most blackberries had reproductive secondary buds that generally survived lower temperatures than the primary buds. Of the red raspberries tested, Canby and Chilliwack had good primary bud hardiness in January and March. Primary buds of red raspberries were usually injured at warmer temperatures than secondary buds. Differential thermal analysis experiments were conducted on primary and secondary buds of Dirksen and Shawnee blackberry and Nordic and Reveille red raspberry at each test date to determine their freezing characteristics. The low temperature exotherms detected in primary buds of each cultivar were correlated with freezing injury, but their number seldom corresponded to the number of differentiated floral primordia. Low temperature exotherms were also detected in some of secondary buds of Dirksen and Reveille which contained differentiated floral primordia.Key words: Blackberries, raspberries, cold hardiness, differential thermal

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.

scholarly journals 334 Seasonal Characterization of the Phenolic Layer Beneath Floral Buds of Rhododendron spp.

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 500E-500
Author(s):  
Michelle R. Salemi ◽  
James D. Scott ◽  
Linda Chalker-Scott
Keyword(s):  
Thermal Analysis ◽  
Low Temperature ◽  
Fluorescence Microscopy ◽  
Preliminary Analysis ◽  
Cold Hardiness ◽  
Floral Buds ◽  
Dormant Season ◽  
Cold Hardy ◽  
The Relationship

It has been previously shown that dormant, cold-hardy floral buds of Azalea possess layers of highly lignified and suberized cells below the bud axis and beneath each bud scale. Two species of deciduous Azalea were analyzed bi-weekly using differental thermal analysis (DTA) throughout their dormant season to determine the development of cold hardiness as denoted by low temperature exotherms (LTEs). Other buds collected at the same time were observed using fluorescence microscopy to document the relationship between the development of the barrier and the onset of cold hardiness. Preliminary analysis showed when buds were maximally cold hardy the barrier was most intact, and as buds began to lose hardiness, the layer started to degrade. These results suggest that in fact this layer of cells does act as the long-proposed bud barrier. In a comparison between the species, the hardier species (R. japonicum) was found to have a denser layer of phenolic-rich cells compared to buds of the less hardy species (R. occidentale). This finding further supports the relationship between the layer of cells and the existence of cold hardiness in bud tissues.

Seasonal and geographic origin effects on cold hardiness of white spruce buds, foliage, and stems

1994 ◽  
Vol 24 (5) ◽  
pp. 1066-1070 ◽  
Author(s):  
David G. Simpson
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Low Temperature ◽  
North American ◽  
Electrolyte Leakage ◽  
Cold Hardiness ◽  
Geographic Origin ◽  
White Spruce ◽  
Stem Tissue ◽  
Early Fall

Cold hardiness of dormant vegetative buds from white spruce (Piceaglauca (Moench) Voss) trees originating from throughout the species' North American range was measured by differential thermal analysis between August and April at Vernon, B.C. Buds were least hardy in early fall (low temperature exotherm −12 to −25 °C) and most hardy midwinter (low temperature exotherms −20 to −34 °C). Buds of northerly origin trees were more hardy in early fall (September–October) than buds of more southerly origin trees. Similar results were observed for foliage and stem tissue in early fall using electrolyte leakage measurements following −16 °C freezing.

scholarly journals CRYOPRESERVATION OF RUBUS FLORAL BUDS IN LIQUID NITROGEN

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1083c-1083
Author(s):  
Jianying Gu ◽  
Michele Warmund ◽  
Milon George
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Survival Rate ◽  
Cooling Rate ◽  
Liquid Nitrogen ◽  
Cold Storage ◽  
Red Raspberry ◽  
Floral Buds ◽  
Thawing Rate ◽  
Cryopreservation Method

Floral buds of `Royalty' purple raspberry and `Heritage' red raspberry were used to develop a cryopreservation method without loss of viability. The effects of prefreezing (PF), cooling rate, thawing rate, and cold storage at -7°C were tested. No survival was observed in samples immersed directly in LN2 whereas `Heritage' and `Royalty' had 90 and 97% survival after holding the samples at -22°C (`Heritage') or -18°C (`Royalty') for one week before immersion in LN2. In all cases, fast thawing resulted in a higher survival rate than slow thawing. Rapid cooling rate decreased the buds survival in LN2, however the effect was diminished when the samples were stored at the PF temperature for one week. The effect of both thawing and PF storage became less critical with bud dehydration. Differential thermal analysis (DTA) was conducted on buds without any PF treatment and buds that were subjected to PF and cold storage. DTA samples that did not receive PF exhibited LTEs, while LTEs were absent in samples subjected PF for one week. Thus, the slow removal of intracellular water to extracellular ice appears to be associated with subsequent survival of Rubus buds in LN2.

scholarly journals Differential Thermal Analysis of ‘Elberta’ and ‘Flavorich’ Peach Flower Buds to Predict Cold Hardiness in Georgia

HortScience ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 676-683 ◽  
Author(s):  
Jun Liu ◽  
Orville M. Lindstrom ◽  
Dario J. Chavez
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Cold Hardiness ◽  
Solid Phase ◽  
Accurate Method ◽  
Experimental Conditions ◽  
Floral Buds ◽  
Artificial Freezing ◽  
Freezing Test ◽  
Floral Bud

Differential thermal analysis (DTA) has great potential as a quick and convenient cold hardiness determination method in plants. It measures freezing events inside of plant samples by detecting exotherm(s) produced when water changes from liquid to solid phase. DTA is highly sensitive to the experimental conditions and it has been reported to be ineffective among different fruit crops after acclimation of floral buds has occurred. The objective of this project was to establish DTA as a rapid and accurate method to predict peach floral bud cold hardiness from acclimation to deacclimation as compared with the traditional standard artificial freezing test. Floral buds of ‘Elberta’ and ‘Flavorich’ peach cultivars were subjected to DTA and artificial freezing tests throughout the winters of 2015–16 and 2016–17. Before deacclimation, two distinct exotherms, low-temperature exotherms (LTE) and high-temperature exotherms (HTE), were normally detected from floral bud DTA analyses. After deacclimation, DTA tests yielded only a few LTEs. However, incubation of floral buds at −2 °C overnight before the cooling process of DTA tests yielded an increased number of LTEs for both seasons in comparison with samples directly run using DTA without incubation. Similarly, after deacclimation started, the temperature in which LTE occurred was correlated (r = 0.59–0.86) with LT50 (lethal temperature that damaged 50% of floral buds) when DTA samples were treated overnight at −2 °C. In our study, pretreatment of floral buds at −2 °C overcame the inability of DTA to detect LTEs after deacclimation, which improved the ability and reliability of DTA to detect LTEs for more than 50% of the buds used per date per cultivar. DTA is a promising method to predict cold hardiness of peach plants.

scholarly journals Supercooling and Extracellular Ice Formation in Differentiating -Buds of Eastern Thornless Blackberry

1992 ◽  
Vol 117 (6) ◽  
pp. 941-945 ◽  
Author(s):  
Michele R. Warmund ◽  
Fumiomi Takeda ◽  
Glen A. Davis
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Low Temperature ◽  
Floral Development ◽  
Early Spring ◽  
Ice Formation ◽  
Anatomical Studies ◽  
Terminal Flower ◽  
Floral Primordia ◽  
Thornless Blackberry

`Hull Thornless' and `Black Satin' blackberry (Rubus spp.) canes were collected from Sept. 1989 through Mar. 1990 to determine the hardiness and supercooling characteristics of buds at various stages of development. Anatomical studies were also conducted to examine the location of ice voids in buds frozen to -5 or -30C. Differentiation of the terminal flower occurred in `Black Satin' buds by 6 Nov., whereas `Hull Thornless' buds remained vegetative until early spring. As many as nine floral primordia were observed in both cultivars by 12 Mar. The hardiness of the two cultivars was similar until February. Thereafter, `Black Satin' buds were more susceptible to cold injury than those of `Hull Thornless'. Flora1 and undifferentiated buds of both cultivars exhibited one to four low temperature exotherms (LTEs) from 9 Oct. to 12 Mar. in differential thermal analysis (DTA) experiments. The stage of flora1 development did not influence the bud's capacity to supercool. The number of LTEs was not related to the stage of floral development or to the number of floral primordia. Extracellular voids resulting from ice formation in the bud axis and scales were observed in samples subjected to -5 or -30C.

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 Breaking Dormancy in Red Raspberry with Hot Water Treatment and its Effects on Cold Hardiness

2006 ◽  
Vol 131 (2) ◽  
pp. 209-213 ◽  
Author(s):  
Pauliina Palonen ◽  
Leena Lindén
Keyword(s):  
Water Treatment ◽  
Cold Hardiness ◽  
Treatment Temperature ◽  
Rubus Idaeus ◽  
Hot Water ◽  
Bud Dormancy ◽  
Hot Water Treatment ◽  
Red Raspberry ◽  
Breaking Dormancy ◽  
Water Treatments

`Maurin Makea', `Muskoka', ` Ottawa', and `Preussen' red raspberry (Rubus idaeus L.) canes were collected from the field and subjected to different hot water treatments (20, 35, 40, 45, and 50 °C) to determine if endodormancy could be removed by a near lethal stress. Estimation of days for 50% budbreak (DD50) was found useful for describing the state of bud dormancy in the samples. Bud dormancy was broken in `Ottawa' by immersing the canes in 45 °C water for 2 hours, in `Maurin Makea' by treating the canes in 40 °C water, and in `Preussen' by both 40 and 45 °C treatments. The influence of this treatment on dormancy and cold hardiness at different times of the winter was further examined using `Ottawa' raspberry. The treatment removed bud dormancy most effectively in October, when the samples were in deepest dormancy. A slight effect was observed in November, but no effect in January. During ecodormancy in February the treatment delayed budbreak. Hot water treatment reduced cold hardiness of `Ottawa' canes by 8 to 15 °C, and that of buds by 9 to 13 °C during both endo- and ecodormancy. Based on the capacity of buds and canes to reacclimate, recovery from the stress treatment was possible at temperatures ≥4 °C. Loss of cold hardiness was caused by high treatment temperature itself and was not related to breaking of dormancy in samples. This finding suggests that dormancy and cold hardiness are physiologically unconnected in raspberry.

Evaluation of low-temperature properties of gas oils via differential thermal analysis

1986 ◽  
Vol 31 (1) ◽  
pp. 21-31
Author(s):  
H. H. Abou El Naga ◽  
A. E. Salem ◽  
D. A. Abd El Ghaffar
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Low Temperature
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