Frost Dehardening and Rehardening of Hydrangea macrophylla Stems and Buds

Hydrangea macrophylla is a popular and commercially important flowering shrub, but frost injury of buds and current-year shoots is a common problem in some of its cultivars. As a result of climate warming, temperate winters are becoming progressively milder, and temperature patterns are becoming increasingly irregular with an increased frequency of warm spells. Warm spells may induce premature dehardening, increasing the risk of subsequent freezing injuries. This study investigated cold-hardiness of stems and buds of Hydrangea macrophylla ssp. macrophylla (Thunb.) Ser. ‘Alma’ during dehardening in response to simulated warm spells and subsequent rehardening in January and early March. Plants were acclimated in the field and dehardened in the greenhouse at controlled warm temperatures for various durations. Dehardened plants were rehardened for up to 12 days in an unheated greenhouse (January) or in the field (March). Buds of H. macrophylla were slightly less cold-hardy than stems. In both stems and buds, the dehardening resistance and the rate of dehardening were influenced by temperature, but buds appeared to be less resistant to dehardening and dehardened faster than stems. In stems, dehardening proceeded faster in March than in January, and the capacity of the stems to reharden seemed reduced, indicating that both dehardening and rehardening were influenced by the progression of winter. Results of this study indicate that buds of H. macrophylla are more sensitive to frost injury than stems and the vulnerability of stems to frost injuries, caused by an unstable temperature regime, changes during the winter season.

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Dehydrins and Soluble Sugars Involved in Cold Acclimation of Rosa wichurana and Rose Cultivar ‘Yesterday’

Horticulturae ◽

10.3390/horticulturae7100379 ◽

2021 ◽

Vol 7 (10) ◽

pp. 379

Author(s):

Lin Ouyang ◽

Leen Leus ◽

Ellen De Keyser ◽

Marie-Christine Van Labeke

Keyword(s):

Cold Acclimation ◽

Cold Hardiness ◽

Prolonged Exposure ◽

Sugar Content ◽

Soluble Sugar ◽

Soluble Sugars ◽

Winter Season ◽

Sugar Metabolism ◽

Northern Regions ◽

Cold Hardy

Rose is the most economically important ornamental plant. However, cold stress seriously affects the survival and regrowth of garden roses in northern regions. Cold acclimation was studied using two genotypes (Rosa wichurana and R. hybrida ‘Yesterday’) selected from a rose breeding program. During the winter season (November to April), the cold hardiness of stems, soluble sugar content, and expression of dehydrins and the related key genes in the soluble sugar metabolism were analyzed. ‘Yesterday’ is more cold-hardy and acclimated faster, reaching its maximum cold hardiness in December. R. wichurana is relatively less cold-hardy, only reaching its maximum cold hardiness in January after prolonged exposure to freezing temperatures. Dehydrin transcripts accumulated significantly during November–January in both genotypes. Soluble sugars are highly involved in cold acclimation, with sucrose and oligosaccharides significantly correlated with cold hardiness. Sucrose occupied the highest proportion of total soluble sugars in both genotypes. During November–January, downregulation of RhSUS was found in both genotypes, while upregulation of RhSPS was observed in ‘Yesterday’ and upregulation of RhINV2 was found in R. wichurana. Oligosaccharides accumulated from November to February and decreased to a significantly low level in April. RhRS6 had a significant upregulation in December in R. wichurana. This study provides insight into the cold acclimation mechanism of roses by combining transcription patterns with metabolite quantification.

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Cold Hardiness Potential of Ten Hydrangea Taxa

Journal of Environmental Horticulture ◽

10.24266/0738-2898-20.3.171 ◽

2002 ◽

Vol 20 (3) ◽

pp. 171-174 ◽

Cited By ~ 1

Author(s):

Jeffrey A. Adkins ◽

Michael A. Dirr ◽

Orville M. Lindstrom

Keyword(s):

Cold Tolerance ◽

Cold Hardiness ◽

Hydrangea Macrophylla ◽

Cold Hardy ◽

Collection Date

Abstract Nine Hydrangea macrophylla (Thunb.) Ser. and one H. serrata (Thunb. ex J.A. Murr.) Ser. cultivars were evaluated for midwinter cold hardiness, acclimation, and deacclimation to identify cultivars with increased cold tolerance. Hydrangea macrophylla ‘Endless Summer’, ‘Mariesii Variegata’, and ‘Veitchii’ acclimated later than all other cultivars. ‘Générale Vicomtesse de Vibraye’ acclimated first, and was cold hardy to −6C (21F) by September 28, 2000. The greatest cold hardiness in all cultivars occurred on January 5, 2001. Maximum cold tolerance in all cultivars was within a 6C (11F) range with ‘Endless Summer’ being the least cold hardy [−18C (0F)], while ‘Dooley’, ‘Générale Vicomtesse de Vibraye’, ‘Mme. Emile Mouillère’, and H. serrata ‘Bluebird’ possessed the greatest cold hardiness [−24C (−11F)] on January 5. Deacclimation in all cultivars began after the January 5 collection date as indicated by the February 1, 2001, data. On March 1,2001, ‘Ayesha’ and ‘Mariesii Variegata’ survived only 4C (39F) while all other cultivars survived at least −6C (21F).

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Flower cold hardiness: a potential determinant of the flowering sequence exhibited by bog ericads

Canadian Journal of Botany ◽

10.1139/b79-123 ◽

1979 ◽

Vol 57 (9) ◽

pp. 997-999 ◽

Cited By ~ 5

Author(s):

R. J. Reader

Keyword(s):

Low Temperatures ◽

Cold Hardiness ◽

Vaccinium Macrocarpon ◽

Southern Ontario ◽

Air Temperatures ◽

Insect Pollinators ◽

Cold Hardy ◽

Vaccinium Myrtilloides ◽

Potential Determinant ◽

Ledum Groenlandicum

In laboratory freezing trials, cold hardiness of six types of bog ericad flowers differed significantly (i.e., Chamaedaphne calyculata > Andromeda glaucophylla > Kalmia polifolia > Vaccinium myrtilloides > Ledum groenlandicum > Vaccinium macrocarpon) at air temperatures between −4 and −10 °C but not at temperatures above −2 °C. At the Luther Marsh bog in southern Ontario, low temperatures (−3 to −7 °C) would select against May flowering by the least cold hardy ericads. Availability of pollinators, on the other hand, would encourage May flowering by the most cold hardy species. Presumably, competition for insect pollinators has promoted the diversification of bog ericad flowering peaks, while air temperature, in conjunction with flower cold hardiness, determined the order in which flowering peaks were reached.

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Super Cooling Point Phenotypes and Cold Resistance in Hyles euphorbiae Hawk Moths from Different Climate Zones

Diversity ◽

10.3390/d13050207 ◽

2021 ◽

Vol 13 (5) ◽

pp. 207

Author(s):

Hana Daneck ◽

Matthias Benjamin Barth ◽

Martin Geck ◽

Anna K. Hundsdoerfer

Keyword(s):

Environmental Conditions ◽

Cold Hardiness ◽

Cold Treatment ◽

Underlying Mechanism ◽

Frost Tolerance ◽

Cold Sensitivity ◽

Cold Hardy ◽

Hyles Euphorbiae

The spurge hawkmoth Hyles euphorbiae L. (Sphingidae) comprises a remarkable species complex with still not fully resolved taxonomy. Its extensive natural distribution range covers diverse climatic zones. This predestinates particular populations to cope with different local seasonally unfavorable environmental conditions. The ability of the pupae to overcome outer frosty conditions is well known. However, the differences between two main ecotypes (‘euphorbiae’ and ‘tithymali’) in terms of the inherent degree of frost tolerance, its corresponding survival strategy, and underlying mechanism have not been studied in detail so far. The main aim of our study was to test the phenotypic exhibition of pupae (as the relevant life cycle stadia to outlast unfavorable conditions) in response to combined effects of exogenous stimuli, such as daylight length and cooling regime. Namely, we tested the turnout of subitan (with fast development, unadapted to unfavorable conditions) or diapause (paused development, adapted to unfavorable external influences and increased resistance) pupae under different conditions, as well as their mortality, and we measured the super cooling point (SCP) of whole pupae (in vivo) and pupal hemolymph (in vitro) as phenotypic indicators of cold acclimation. Our results show higher cold sensitivity in ‘tithymali’ populations, exhibiting rather opportunistic and short-termed cold hardiness, while ‘euphorbiae’ produces a phenotype of seasonal cold-hardy diapause pupae under a combined effect of short daylight length and continuous cold treatment. Further differences include the variability in duration and mortality of diapause pupae. This suggests different pre-adaptations to seasonal environmental conditions in each ecotype and may indicate a state of incipient speciation within the H. euphorbiae complex.

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Analysis of climate of Rivnenskyi Nature Reserve from 2000 to 2015

Visnyk of the Lviv University. Series Geography ◽

10.30970/vgg.2018.52.10168 ◽

2018 ◽

pp. 53-60

Author(s):

Oleksandr Horbach

Keyword(s):

Nature Reserve ◽

Winter Season ◽

Summer Season ◽

Daily Temperature ◽

Winter Period ◽

Autumn Period ◽

Average Daily Temperature ◽

Spring Period ◽

Unstable Temperature

The analysis of monthly climatic terms of Rivnenskyi Nature Reserve was conducted. It is marked that weather terms have substantial differences due to an unstable temperature condition since creation of reserve. A spring period was the shortest in 2013 – 64 days and had the greatest average daily temperature 11.9 °С. Protracted a spring period was in 2002 – 123 days. The most of precipitations in a spring period was fixed in 2008 – 196.2 mm, and the least in 2011 – 42.1 mm. A summer period in 2015 became the most protracted – 131 day. Moreover, the least protracted summer was in 2006 – 90 days. The warmest summer season was in 2010 with an average daily temperature 19.8 °С. The most raining summer was in 2007 when a 471.3 mm of precipitations is fixed, and the least raining summer was in 2002 (144.6 mm of precipitations). The most protracted autumn period was in 2006 – 107 days and the shortest one was in 2001 – 57 days. The warmest autumn was in 2004 when an average daily temperature reached 9.2°С. The most of precipitations in the autumn period is fixed in 2009 – 178 mm, and the least in 2001 – 39 mm. The winter periods were protracted in 2004/05 and 2005/06. Their duration was 114 days. Winter period in 2009/10 with an average daily temperature -7.9°С was the coldest one. The most precipitations are fixed in winter 2005/06 – 208.4 mm, and the least in a winter period 2012/13 are a 52.2 mm. The most of precipitations for a year fell out 777.8 mm in 2012, and the least one in 2011 – 427 mm. The average long-term dates of the beginning of the year seasons are defined. The average long-term date of the beginning of the spring season is on February 27; the summer season is on May 26; the autumn season is on September 14; the winter season is on December 5. Key words: Rivnenskyi Nature Reserve, seasons of the year, precipitation, climatic terms, temperature, long-term date.

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Current state of cold hardiness research on fruit crops

Canadian Journal of Plant Science ◽

10.4141/p96-013 ◽

1997 ◽

Vol 77 (3) ◽

pp. 399-420 ◽

Cited By ~ 26

Author(s):

Pauliina Palonen ◽

Deborah Buszard

Keyword(s):

Cold Hardiness ◽

Cultural Practices ◽

Limiting Factor ◽

Screening Methods ◽

Fruit Crops ◽

Factors Affecting ◽

Fruit Species ◽

Current State ◽

Deep Supercooling ◽

Cold Hardy

This article gives an overview of the current state of cold hardiness research in fruit crops by reviewing the recently published studies on cold hardiness of both tree fruit and berry crops. Topics discussed include cold hardiness of fruit species, cultivars and different plant organs, biophysical and biochemical aspects of hardiness, evaluation of hardiness, as well as endogenous, cultural and environmental factors affecting cold hardiness in these species. Lack of cold hardiness is a major limiting factor for production of fruit crops in many regions of the world and improved cold hardiness one of the major objectives in numerous breeding programs and research projects. Screening cultivars or selections for cold hardiness is commonly done, and different methods applied to the evaluation of hardiness are discussed. The physical limit of deep supercooling may be a restricting factor for expanding the production of some fruit crops, such as Prunus species and pear. As for biochemical aspects, a relationship between carbohydrates and cold hardiness is most commonly found. Studies have also been made on different hardiness modifying cultural factors including rootstock, crop load, raised beds and application of growth regulators. The latter seems promising for some species. Cold hardiness is an extremely complex phenomenon and understanding different mechanisms involved is critical. Since hardiness is, however, primarily affected by genotype, developing cold-hardy fruit cultivars and effective screening methods for hardiness are essential. Finally, cultural practices may be improved to further enhance hardiness. Key words: Berries, cold hardiness, fruits, small fruits, stress, winter hardiness

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Cold-Hardiness, Habitat and Winter Survival of Some Orchard Arthropods in Nova Scotia

The Canadian Entomologist ◽

10.4039/ent96617-4 ◽

1964 ◽

Vol 96 (4) ◽

pp. 617-625 ◽

Cited By ~ 29

Author(s):

A. W. MacPhee

Keyword(s):

Nova Scotia ◽

Air Temperature ◽

Low Temperatures ◽

Cold Hardiness ◽

Winter Survival ◽

Kings County ◽

Winter Conditions ◽

Cold Hardy

AbstractIn Kings County, Nova Scotia, low temperatures in the coldest nights of winter can differ by as much as 10°F. from one area to another. This has an important bearing on winter survival of some arthropods. Overwintering sites of orchard arthropods range from exposed situations which remain at air temperature to well protected ones on the ground where temperatures rarely go below 20°F. The cold-hardiness of each of 24 species of arthropods was measured: seven were sufficiently cold-hardy to survive any winter conditions in Nova Scotia, five were less cold-hardy but overwinter in well protected sites and twelve had marginal cold-hardiness, their mortality varying with the winter and the locality.

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COLD HARDINESS IN HEXAPLOID TRITICALE

Canadian Journal of Plant Science ◽

10.4141/cjps85-070 ◽

1985 ◽

Vol 65 (3) ◽

pp. 487-490 ◽

Cited By ~ 12

Author(s):

A. E. LIMIN ◽

J. DVORAK ◽

D. B. FOWLER

Keyword(s):

Cold Hardiness ◽

Tetraploid Wheat ◽

Triticum Aestivum L ◽

Hexaploid Triticale ◽

D Genome ◽

Potential Source ◽

Secale Cereale L ◽

Cold Hardy ◽

Triticosecale Wittmack ◽

X Triticosecale Wittmack

The excellent cold hardiness of rye (Secale cereale L.) makes it a potential source of genetic variability for the improvement of this character in related species. However, when rye is combined with common wheat (Triticum aestivum L.) to produce octaploid triticale (X Triticosecale Wittmack, ABDR genomes), the superior rye cold hardiness is not expressed. To determine if the D genome of hexaploid wheat might be responsible for this lack of expression, hexaploid triticales (ABR genomes) were produced and evaluated for cold hardiness. All hexaploid triticales had cold hardiness levels similar to their tetraploid wheat parents. Small gains in cold hardiness of less than 2 °C were found when very non-hardy wheats were used as parents. This similarity in expression of cold hardiness in both octaploid and hexaploid triticales indicates that the D genome of wheat is not solely, if at all, responsible for the suppression of rye cold hardiness genes. There appears to be either a suppressor(s) of the rye cold hardiness genes on the AB genomes of wheat, or the expression of diploid rye genes is reduced to a uniform level by polyploidy in triticale. The suppression, or lack of expression, of rye cold hardiness genes in a wheat background make it imperative that cold-hardy wheats be selected as parents for the production of hardy triticales.Key words: Triticale, Secale, winter wheat, cold hardiness, gene expression

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Intensive short rotation forestry in boreal climates: present and future perspectives

Canadian Journal of Forest Research ◽

10.1139/x04-090 ◽

2004 ◽

Vol 34 (7) ◽

pp. 1369-1378 ◽

Cited By ~ 109

Author(s):

Martin Weih

Keyword(s):

Cold Hardiness ◽

Production Systems ◽

Rapid Development ◽

Winter Season ◽

Rotation Period ◽

Agricultural Landscapes ◽

Short Rotation ◽

Silvicultural Practice ◽

Biomass Yields ◽

Boreal Climate

Short rotation forestry (SRF) is regarded as a silvicultural practice employing high-density plantations of fast-growing tree species on fertile land with a rotation period of fewer than 1012 years. I address the challenges and possibilities of SRF applications under the circumstances of a boreal climate, today as well as after anticipated climate change. The implications of a pronounced winter season for the performance of biomass crops are discussed. Poplars, aspens, and willows are superior in boreal SRF because of their fast growth rate in combination with good cold hardiness. These trees can enrich the coniferous forests of boreal regions and increase biodiversity in open agricultural landscapes of the boreal zone. Further, SRF plantations can serve as tools for the amelioration of environmental problems at local (e.g., phytoremediation) and global (e.g., increased greenhouse effect) scales. The biomass yields achieved in boreal SRF and the appropriate production systems appear do not appear to be principally different from warmer regions, but there are some differences with respect to the importance of fertilization, appropriate spacing, and rotation length. The major barriers for a rapid development of SRF appear not to be climatic, technical, or environmental constraints in many boreal regions.

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