scholarly journals Cold-hardiness and Deacclimation of Styrax americanus from Three Provenances

HortScience ◽  
2010 ◽  
Vol 45 (12) ◽  
pp. 1819-1823 ◽  
Author(s):  
Olivia M. Lenahan ◽  
William R. Graves ◽  
Rajeev Arora
Keyword(s):  
Low Temperature ◽  
Cold Hardiness ◽  
Small Tree ◽  
Time Intervals ◽  
Southern Illinois ◽  
Disjunct Population ◽  
Patchy Populations ◽  
Cold Hardy ◽  
Deciduous Shrub ◽  
Stem Segments

Styrax americanus Lam. (American snowbell) is a deciduous shrub or small tree seldom produced in nurseries. This species is distributed in patchy populations found mainly from Florida to southern Illinois, although a small, disjunct population exists in northern Illinois. The winter-hardiness and loss of hardiness during a period of increased temperature (deacclimation) of plants from this disjunct population may differ from those of S. americanus elsewhere. We examined cold-hardiness and deacclimation of stems of plants from the disjunct population, from southern Illinois, and from Florida. Segments of stems removed from plants grown outdoors in Ames, IA, were exposed to low-temperature ramping, and the temperature at which stems showed 50% damage (LT50) was determined by using the tissue-discoloration method. To assess deacclimation, stem segments were collected from cold-acclimated plants during winter in a minimally heated greenhouse and exposed to controlled warm temperatures for various time intervals followed by low-temperature ramping. Plants from Illinois were ≈15 °C more cold-hardy than plants from Florida in Feb. 2008. Plants from the disjunct population in northern Illinois showed less stem tip injury than did plants from southern Illinois. Deacclimation patterns were similar between plants from both Illinois populations. Plants sampled in Apr. 2009 from Florida deacclimated more rapidly than corresponding samples from Illinois, and the chilling required to overcome endodormancy increased with increasing latitude of plant origin. This research suggests that germplasm from the Illinois populations should be used in regions where the poorer hardiness and deacclimation resistance of most S. americanus would not permit survival.

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.

A comparison of the cold hardiness of populations of Delia radicum (L.) (Diptera: Anthomyiidae) from southern England and the Canadian Prairies

1990 ◽  
Vol 68 (5) ◽  
pp. 830-835 ◽  
Author(s):  
W. J. Turnock ◽  
P. M. Reader ◽  
G. K. Bracken
Keyword(s):  
Low Temperature ◽  
Cold Hardiness ◽  
Cold Injury ◽  
Delia Radicum ◽  
Supercooling Point ◽  
Canadian Prairies ◽  
Canadian Population ◽  
English Population ◽  
Cold Hardy ◽  
The Relationship

The Canadian population of Delia radicum is more cold hardy than the English population in that the supercooling point is slightly lower and overwintering pupae are less sensitive to lower temperatures and longer exposure times. However, the Canadian population is slightly less cold hardy at higher temperatures within the cold injury zone. Female D. radicum were more susceptible to cold-induced mortality than males among the Canadian population, but this sex difference was not significant in the English population. The proportion of malformed adults and the rate of postdiapause development were not related to cold injury in either population. The bounds of the cold injury zone for species or populations of freezing susceptible, diapausing insects plus the sensitivity of the species to cold injury within this zone can provide an ecologically sound method of describing cold hardiness. Sensitivity, measured by the slope of a regression describing the relationship between survival and the duration of exposure at a low temperature, can also be used to calculate the rate at which cold injury occurs at any temperature within the cold injury zone. This slope may reflect the overwintering conditions of a species or population because Canadian populations of both D. radicum and Mamestra configurata (Noctuidae) have similar coefficients, but these are very different from the coefficient of the English population of D. radicum. The supercooling point did not provide a useful indication of the susceptibility of these cold-hardy diapausing insects to cold injury.

scholarly journals Cold Hardiness of Weigela Cultivars

1998 ◽  
Vol 16 (4) ◽  
pp. 238-242 ◽  
Author(s):  
Steve McNamara ◽  
Harold Pellett
Keyword(s):  
Low Temperature ◽  
Cold Hardiness ◽  
Temperature Tolerance ◽  
Cold Injury ◽  
Late Winter ◽  
Freeze Thaw ◽  
Lethal Temperatures ◽  
Low Temperature Tolerance ◽  
Temperature Controlled ◽  
Cold Hardy

Abstract Laboratory freezing tests of stem hardiness were conducted to develop cold hardiness profiles for 18 weigela (Weigela sp.) cultivars during the fall and winter of 1994–95. Tests were performed on containerized plants held in a temperature-controlled greenhouse to prevent exposure to potentially lethal temperatures. No cultivar survived below −6C (21F) in the October 3 test. Subsequent differences in rates of acclimation resulted in cultivars differing in hardiness by as much as 13C (23F) on November 14. Taxa also differed greatly in their maximum midwinter low temperature tolerance with ‘Centennial’ and ‘Eva Supreme’ hardy to −44C (−47F) and −28C (−18F) in mid-January, respectively. None of the cultivars deacclimated substantially in response to a week of artificially-imposed diurnal freeze/thaw cycles in early February. Taxa with the greatest midwinter hardiness also maintained the greatest hardiness in early March. Overall, ‘Centennial’, ‘Java Red’, and ‘Samba’ were the most cold hardy cultivars tested, while ‘Boskoop Glory’, ‘Bristol Snowflake’, and ‘Variegata’ were the least hardy. Cold injury of susceptible weigela cultivars appears to be a consequence of late hardening and/or insufficient midwinter hardiness rather than rapid deacclimation in response to periods of warm temperatures in mid-to late-winter.

scholarly journals Gene Expression Analysis a Cold Responsive Gene from Poncirus trifoliata during Acclimation and Deacclimation

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 862C-862
Author(s):  
Adriana Robbins ◽  
Ying Jia ◽  
Eliezer Louzada*
Keyword(s):  
Low Temperature ◽  
Expression Analysis ◽  
Low Temperatures ◽  
Cold Hardiness ◽  
Poncirus Trifoliata ◽  
Trifoliate Orange ◽  
Rt Pcr ◽  
Reading Frame ◽  
Transcript Stability ◽  
Cold Hardy

In Texas, the freezes of 1951 and 1962 together killed 125,000 acres of citrus trees and the freeze of 1983 killed 40,000 acres. The low temperature is one of the most important abiotic stresses to be understood and manipulated molecularly. Cold hardiness is found in the deciduous citrus relative, trifoliate orange, which can withstand temperatures as low as -26 °C when it is cold acclimated. Exposure of the cold hardy trifoliate orange plants to temperature from 28 °C to -5 °C enabled us to isolate and characterize one novel citrus low temperature gene (clt) with two transcripts, called clt-a and clt-b from leaves and twigs. Clt-a was produced when plants were subjected to low temperatures (starting at 10 °C), while cltb was constitutively expressed. Both clt-a and clt-b have the same open reading frame of 165 nucleotides and encodes a small protein of 54 amino acid. However, clt-a has an additional 98 bp nucleotides at the 3'-untranslated region (UTR), which is absent in clt-b. Expression analysis using relative quantitative RT-PCR demonstrated that clt-a is expressed exclusively at low temperatures, while clt-b is expressed constitutively (expression verified from 2 °C to -5 °C). In the process of deacclimation from -1 °C to 28 °C, the clt-a transcript degraded dramatically after 2 °C and was completely absent at 28 °C, while the clt-b transcript remain stable. When the acclimated plant was taken from -1 °C to room temperature, the clt-a gene degraded within 2 hours. Moreover, when acclimated plant was continuously exposed at -1 °C for 20 days, both transcripts clt-a and clt-b remained stable. Involvement of alternative splicing in transcript stability will be discussed.

scholarly journals Frugivory by Coyotes Decreases the Time to Germination and Increases the Growth of Netleaf Hackberry (Celtis reticulata) Seedlings

Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 727
Author(s):  
Michael T. Stevens ◽  
Sydney Houghton ◽  
Hannah A. Veltkamp
Keyword(s):  
Seedling Survival ◽  
Final Height ◽  
Germination Percentage ◽  
Small Tree ◽  
Additional Time ◽  
Wasatch Mountains ◽  
Animal Interaction ◽  
Semi Arid Region ◽  
Common Plant ◽  
Deciduous Shrub

Research Highlights: Frugivory by mammals is a common plant–animal interaction, but additional studies that examine the effects of frugivory on woody plants are needed. We show that ingestion of netleaf hackberry (Celtis reticulata Torr.) fruits by coyotes (Canis latrans Say) cuts the time to germination nearly in half and results in seedlings that are taller than the controls. Background and Objectives: Netleaf hackberry is a deciduous shrub to small tree that can be long-lived, but newly established stands are rare. The lack of juvenile hackberry in its native range of southwestern North America could be due to low percentages of germination and seedling survival. We hypothesized that passage through the digestive tract of a coyote would increase the germination and subsequent growth of netleaf hackberry. Materials and Methods: In the Wasatch Mountains of Utah, we collected coyote scats containing visible hackberry fruits and picked fresh fruits from nearby hackberry shrubs. All samples were cleaned and cold-stratified. We sowed 20 seeds from each of the 34 samples into containers in the greenhouse (a total of 680 seeds). We noted the date of emergence and final height of each seedling after 131 days. Results: The germination percentage of the coyote-treatment seeds did not differ from that of the controls. However, the coyote-ingested seeds took just over half as many days to germinate as did the undigested controls (35 days vs. 69 days, respectively; p < 0.001) and the resulting seedlings were 9.5% taller by the end of the growing season (6.4 vs. 5.8 cm, respectively; p < 0.001). Conclusions: Consumption by coyotes can benefit hackberries by enabling their seeds to germinate earlier in the year when conditions are wetter and cooler. The additional time for establishment and growth afforded by frugivory likely increases the fitness of netleaf hackberry seedlings that emerge into the unpredictable conditions of a semi-arid region.

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

1979 ◽  
Vol 57 (9) ◽  
pp. 997-999 ◽  
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.

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

Diversity ◽  
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.

scholarly journals Cold Hardiness and Vernal Budbreak of Rhamnus caroliniana and the Invasive Rhamnus cathartica

2006 ◽  
Vol 131 (3) ◽  
pp. 345-351 ◽  
Author(s):  
J. Ryan Stewart ◽  
William R. Graves ◽  
Reid D. Landes
Keyword(s):  
United States ◽  
Water Stress ◽  
Cold Hardiness ◽  
Southeastern United States ◽  
The United States ◽  
Rhamnus Cathartica ◽  
Small Tree ◽  
Natural Distribution ◽  
Ecological Problems ◽  
Managed Landscapes

Carolina buckthorn [Rhamnus caroliniana Walt. or Frangula caroliniana (Walt.) Gray] is an attractive and water-stress-resistant shrub or small tree distributed extensively in the southeastern United States that merits use in managed landscapes. Due to substantial climatic differences within its distribution (30-year normal midwinter minima range from 13 to -8 °C), selection among provenances based on differences in cold hardiness is warranted. Before selections are marketed, the potential of carolina buckthorn to be invasive also merits investigation. Ecological problems resulting from the introduction of Rhamnus L. species in the United States, most notably the dominance of R. cathartica L. (common buckthorn) over neighboring taxa, are due in part to early budbreak. Consequently, we investigated depth of cold hardiness and vernal budbreak of carolina buckthorn and common buckthorn. Stem samples of carolina buckthorn and common buckthorn collected in midwinter survived temperatures as low as -21 and -24 °C, respectively. Although the cold hardiness of carolina buckthorns from Missouri was greater than that of carolina buckthorns from Ohio and Texas on 2 Apr. 2003, there were no differences in cold hardiness of stems from Missouri and Texas on all three assessment dates in the second experiment. All plants survived at both field locations except for the carolina buckthorns from southern Texas planted in Iowa, which showed 0% and 17% survival in 2003 and 2004, respectively. Budbreak of both species with and without mulch in Ames, Iowa, was recorded from 9 Apr. to 10 May 2002. Mean budbreak of common buckthorn was 5.7 days earlier than budbreak of carolina buckthorn, and buds of mulched carolina buckthorns broke 4.2 days earlier than did buds of unmulched carolina buckthorns. We conclude that the cold hardiness of carolina buckthorn is sufficient to permit the species to be planted outside of its natural distribution. Populations of carolina buckthorn in Ohio and Missouri should be the focus of efforts to select genotypes for use in regions with harsh winters. Phenology of its budbreak suggests carolina buckthorn will not be as invasive as common buckthorn, but evaluation of additional determinants of invasiveness is warranted.

Current state of cold hardiness research on fruit crops

1997 ◽  
Vol 77 (3) ◽  
pp. 399-420 ◽  
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

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

1964 ◽  
Vol 96 (4) ◽  
pp. 617-625 ◽  
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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