scholarly journals Freezing Tolerance of 27 Saltgrass Ecotypes from Three Cold Hardiness Zones

HortScience ◽  
2007 ◽  
Vol 42 (1) ◽  
pp. 157-160 ◽  
Author(s):  
Hrvoje Rukavina ◽  
Harrison G. Hughes ◽  
Yaling Qian
Keyword(s):  
Abiotic Stress ◽  
Freezing Tolerance ◽  
Cold Hardiness ◽  
Warm Season ◽  
Lethal Temperature ◽  
Northern Areas ◽  
Fort Collins ◽  
Freezing Test ◽  
Cold Hardy ◽  
Collection Sites

Freezing is the major abiotic stress that limits geographic distribution of warm season turfgrasses. Prior studies have indicated variation in freezing tolerance in saltgrass clones. Therefore, this study examined freezing tolerance of 27 saltgrass clones as related to collection sites in three zones of cold hardiness. Furthermore, these clones were evaluated for time of leaf browning in the fall with the intent to determine if there was a correlation between this trait and freezing tolerance. Rhizomes were sampled during 2004 and 2005 midwinters from clones established in Fort Collins, Colo., and then subjected to a freezing test in a programmable freezer. Saltgrass freezing tolerance was highly influenced by the climatic zone of clone origin in both years of the experiment. Clones with greater freezing tolerance turned brown earlier in fall in both seasons. Ranking of zones for the average LT50 (lethal temperature at which 50% of rhizomes died) was: zone 4, most northern (−17.2 °C) < zone 5 (−14.4 °C), < zone 6, most southern (−11.1 °C) in 2004, and zone 4 (−18.3 °C), < zone 5 (−15.7 °C) < zone 6 (−13.1 °C) in 2005. Clones from northern areas tolerated lower freezing temperatures overall. This likely indicates that freezing tolerance is inherited. Large intraspecific variation in freezing tolerance may be effectively used in developing cold hardy cultivars.

scholarly journals (53) Freezing Tolerance of Twenty-Seven Saltgrass Ecotypes Was Similar in 2004 and 2005

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1038A-1038
Author(s):  
Hrvoje Rukavina ◽  
Harrison Hughes ◽  
Yaling Qian
Keyword(s):  
Abiotic Stress ◽  
Geographical Distribution ◽  
Freezing Tolerance ◽  
Cold Hardiness ◽  
Warm Season ◽  
Northern Areas ◽  
Fort Collins ◽  
Freezing Test ◽  
Cold Hardy ◽  
Collection Sites

Freezing is the major abiotic stress that limits geographical distribution of warm-season turfgrasses. Prior studies have indicated variation in freezing tolerance in saltgrass clones. Therefore, this 2-year study examined the freezing tolerance of 27 saltgrass clones as related to collection sites in three zones of cold hardiness. Furthermore, these clones were evaluated for time of leaf browning in the fall with the intent to determine if there was a correlation between this trait and freezing tolerance. Rhizomes were sampled during 2004 and 2005 midwinters from clones established in Fort Collins, Colo., and then subjected to a freezing test. Saltgrass freezing tolerance was highly influenced by the climatic zone of clone origin in both years of the experiment. Clones with greater freezing tolerance turned brown earlier in fall in both seasons. Ranking of zones for the average LT50 was: zone 4 (–17.2 °C) < zone 5 (–14.4 °C) < zone 6 (–11.1 °C) in 2004 and zone 4 (–18.3 °C) < zone 5 (–15.7 °C) < zone 6 (–13.1 °C) in 2005. Clones from northern areas tolerated lower freezing temperatures better overall. This confirmed that freezing tolerance is inherited. Large intraspecific variation in freezing tolerance may be effectively used in developing cold-hardy cultivars.

scholarly journals Freezing Tolerance of Saltgrass (Distichlis spicata) Ecotypes

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1106D-1106
Author(s):  
Hrvoje Rukavina ◽  
Harrison Hughes ◽  
Yaling Qian
Keyword(s):  
Freezing Tolerance ◽  
Cold Hardiness ◽  
Selection Criterion ◽  
Least Square ◽  
State University ◽  
Colorado State University ◽  
Color Retention ◽  
Fort Collins ◽  
Freezing Test ◽  
Cold Hardy

Efforts are ongoing at Colorado State University to develop turf-type saltgrass cultivars. Prior freezing studies have indicated variation in freezing tolerance in saltgrass lines. Therefore, this study was made to examine relative freezing tolerance of 27 saltgrass clones as related to collection sites in three zones of cold hardiness. Furthermore, these lines were evaluated for fall color retention with the intent to determine if there is a correlation with fall color and freezing tolerance. Saltgrass rhizomes were sampled in mid-winter 2004 from lines established in Fort Collins, Colo., and then subjected to a laboratory-freezing test. Saltgrass freezing tolerance was highly influenced by climate zones of clones' origin (P < 0.01) and genotypes within zones (P < 0.01). There was a high negative correlation between color retention in the fall and freezing tolerance (P < 0.01). Average freezing tolerance of saltgrass clones within zones of origin significantly differed among zones. Ranking of zones for least square mean LT50 (OC) was: zone 4 (–17.2) < zone 5 (-14.4) < zone 6 (–11.1). LT50 values in zone 4 ranged from –17.8 (accession 72) to –17.0 (accession 87). Clones in zone 5 showed LT50 values from –17.8 (accession A29) to –11.9 (accession A137). Zone 6 clones had LT50 values that ranged from –9.5 (accession C92) to –12.6 (accession C12). Large intraspecific variation in freezing tolerance may be effectively used in new cold hardy cultivar development. Environmental adaptation inherited by origin of clone is useful in defining clones' adaptation range and may along with fall color retention serve as a selection criterion in saltgrass cold hardiness improvement.

scholarly journals A Rapid Method for Detection of Cold Hardiness in Roses

HortScience ◽  
1991 ◽  
Vol 26 (1) ◽  
pp. 59-60 ◽  
Author(s):  
Fadi H. Karam ◽  
J. Alan Sullivan
Keyword(s):  
Rapid Method ◽  
Freezing Tolerance ◽  
Cold Hardiness ◽  
Laboratory Conditions ◽  
Rose Breeding ◽  
Cold Hardy

Distinct differences in freezing tolerance among a cold-hardy wild rose species Rosa fedtschenkoana Regel., a garden rose, `Jack Frost', and their hybrid could be detected under laboratory conditions using 2-cm-long shoot segments with buds. The garden rose did not survive - SC, but the cold-hardy species survived freezing to -10C and the hybrid to –5C. One week of acclimation at 4C was adequate for R. fedtschenkoana; longer periods did not improve the rate of survival. Immersing tissue in 5%, 10%, or 20% sucrose during acclimation improved the rate of survival of R. fedtschenkoana but not of `Jack Frost'. Applications to rose breeding are discussed.

Switch in the overwintering strategy of two insect species and latitudinal differences in cold hardiness

1989 ◽  
Vol 67 (4) ◽  
pp. 825-827 ◽  
Author(s):  
Olga Kukal ◽  
John G. Duman
Keyword(s):  
Freezing Tolerance ◽  
Temperature Regime ◽  
Low Temperatures ◽  
Cold Hardiness ◽  
Geographical Location ◽  
Dendroides Canadensis ◽  
Latitude Range ◽  
Low Latitudes ◽  
Different Populations ◽  
Cold Hardy

A switch from freezing tolerance to freezing intolerance (avoidance) occurred between winter 1980 and winter 1981 in Dendroides canadensis and between 1979 and 1983 in Cucujus clavipes at the same geographical location in northern Indiana (41°30′N). This change in overwintering strategy was not related to latitudinal interpopulation differences, because different populations (latitude range 35°30′N–45°20′N) subsequently sampled were all intolerant of freezing. A 1-week midwinter thaw had no effect on the overwintering mode or cold hardiness of the midlatitude population of D. canadensis. However, high-latitude populations of D. canadensis were more cold hardy (survived 24-h freezing at temperatures above −25 °C) than populations from low latitudes (survived freezing at temperatures above −15 °C). All individuals of the northernmost populations survived low temperatures (−15 °C for 2 weeks) whereas only 14% of the southern-ranging individuals survived that temperature regime.

DEVELOPMENT OF A TEST FOR FREEZING TOLERANCE IN YOUNG ALFALFA SEEDLINGS

1990 ◽  
Vol 70 (1) ◽  
pp. 307-310 ◽  
Author(s):  
Y. CLOUTIER ◽  
L. PELLETIER ◽  
R. MICHAUD
Keyword(s):  
Medicago Sativa ◽  
Freezing Tolerance ◽  
Frost Resistance ◽  
Cold Hardiness ◽  
Cold Hardening ◽  
Reliable Test ◽  
Seedling Age ◽  
Additional Information ◽  
Medicago Sativa L ◽  
Freezing Test

An experiment was conducted to study the effects of seedling age on their ability to harden, and to determine whether cultivar × seedling age interaction could be identified for frost resistance. In the present study, 6- to 24-d-old alfalfa (Medicago sativa L.) seedlings were significantly more freezing-tolerant after cold-hardening than unhardened controls. Cold-hardened seedlings of age varying from 8 to 24 d were hardier than 6-d-old seedlings. No cultivar × seedling age interaction was found. The best separation of the cultivars occurred between 18 and 24 d. These findings provide additional information towards the development of a rapid and reliable test for estimating freezing tolerance in alfalfa.Key words: Freezing test, alfalfa, cold hardiness, seedlings

scholarly journals (438) Searching for Cold Hardy Lace-bark Elm (Ulmus parvifolia Jacq.) for Northern Latitudes

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1077C-1077
Author(s):  
A.M. Shirazi ◽  
G.H. Ware
Keyword(s):  
Seed Germination ◽  
Cold Hardiness ◽  
The United States ◽  
Dutch Elm Disease ◽  
Great Promise ◽  
Urban Landscapes ◽  
Ulmus Parvifolia ◽  
Northern Latitudes ◽  
Freezing Test ◽  
Cold Hardy

The genus Ulmus contains numerous stress-tolerant species, especially those from areas of China with climates similar to various regions of the United States. Lace-bark elm, Ulmus parvifolia, the true Chinese elm, has an extensive temperature distribution range in China and offers great promise as a street tree. The high resistance of this elm to Dutch elm disease and other elm problems makes it an excellent tree for urban landscapes. Two new U. parvifolia cultivars, Athena® and Allee®, are not cold hardy for northern climates and there is a need for new cold hardy lace-bark elms. Screening thousands of seedlings for cold hardiness, upright form, beautiful bark characteristics, and larger leaves will bring the most desirable U. parvifolia cultivars into the green industry. We determined that seed dormancy and the percentage of seed germination of four selected lacebark elms after 2 and 4 weeks were >30% and >50%, respectively. There were significant differences in stem cold hardiness among new lace-bark elms from China (about –32 to –40 °C). Laboratory determination of cold hardiness can provide great advantages over years of field testing. Response to the outdoor temperature in December, January, and February on a seed cold hardiness freezing test showed significant reduction in seed germination, especially at –30 °C. Freezing test of seeds to –40 °C, resulted in lt50 of –3 to –5 °C in December, so, it is less likely that these U. parvifoilia will become invasive in northern latitudes. Invasiveness of these U. parvifolia for higher zones, e.g., 6–8 could be greater and selection of these elms is suitable for zones 5 and lower. Planting these elms in zones 4, 3, and 2 will give us useful information regarding their winter performance.

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.

COLD HARDENING AND DEHARDENING RESPONSES IN WINTER WHEAT AND WINTER BARLEY

1975 ◽  
Vol 55 (2) ◽  
pp. 529-535 ◽  
Author(s):  
M. K. POMEROY ◽  
C. J. ANDREWS ◽  
G. FEDAK
Keyword(s):  
Winter Wheat ◽  
Cold Hardiness ◽  
Maximum Level ◽  
Freezing Temperature ◽  
Triticum Aestivum L ◽  
Winter Barley ◽  
Lethal Temperature ◽  
Hordeum Vulgare L ◽  
Wheat Seedlings ◽  
Time Required

Increasing the duration of freezing of Kharkov winter wheat (Triticum aestivum L.) demonstrated that severe injury does not occur to plants at a freezing temperature (−6 C) well above the lethal temperature for at least 5 days, but progressively more damage occurs as the temperature approaches the killing point (−20 C). High levels of cold hardiness can be induced rapidly in Kharkov winter wheat if seedlings are grown for 4–6 days at 15 C day/10 C night, prior to being exposed to hardening conditions including diurnal freezing to −2 C. The cold hardiness of Kharkov and Rideau winter wheat seedlings grown from 1-yr-old seed was greater than that from 5-yr-old seed. Cold-acclimated Kharkov winter wheat and Dover winter barley (Hordeum vulgare L.) demonstrated the capacity to reharden after varying periods under dehardening conditions. The time required to reharden and the maximum level of hardiness attained by the plants was dependent on the amount of dehardening. Considerable rehardening was observed even when both dehardening and rehardening were carried out in the dark.

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.

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

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