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

THE IMPORTANCE OF LEAF FROST RESISTANCE TO THE WINTER SURVIVAL OF SEEDLING STANDS OF ALFALFA

1982 ◽  
Vol 62 (2) ◽  
pp. 399-405 ◽  
Author(s):  
J. S. McKENZIE ◽  
G. E. McLEAN
Keyword(s):  
Medicago Sativa ◽  
Frost Resistance ◽  
Frost Damage ◽  
Winter Survival ◽  
Single Plant ◽  
Leaf Injury ◽  
Medicago Sativa L ◽  
Freezing Temperatures ◽  
Freezing Chamber

Plants propagated from single plant selections of the alfalfa cultivars Saranac and Luna (Medicago sativa L.), Beaver (M. media Pers.) and Anik (M. falcata L.) were transplanted into the field in May and subjected to a range of freezing temperatures at 3-wk intervals during August and September. A portable field freezing chamber was used to study the influence of frost on leaf injury in the fall and winterkill following the severe 1977–1978 winter. Leaves of all plants had the capacity to harden during the fall, but the selection from Anik was consistently the most frost hardy. Temperatures ranging from −4 to −5 °C in mid-August caused 50% leaf injury to the selections of Beaver, Saranac and Luna, while in late September, temperatures ranging from −9.5 to −10.5 °C were required to produce similar amounts of injury. In the Anik selection, −6 °C in mid-August caused 50% leaf injury, but in late September −12.5 °C caused less than 35% injury. Thus, the Anik selection appeared to start hardening about 3 wk earlier than all other selections. In all plants, the potential for winter injury during the 1977–1978 winter increased as a result of leaf frost damage during mid-August and early September in 1977. The application of these results to the winter survival of seedling stands of alfalfa is discussed.

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 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.

Further studies on the determination of cold hardiness in Trifolium repens L. and Medicago sativa L.

1960 ◽  
Vol 11 (1) ◽  
pp. 1 ◽  
Author(s):  
CG Greenham ◽  
H Daday
Keyword(s):  
Medicago Sativa ◽  
Trifolium Repens ◽  
Cold Hardiness ◽  
Cold Treatment ◽  
Low Frequency ◽  
Resistance Index ◽  
Medicago Sativa L ◽  
Trifolium Repens L ◽  
Probe Measurements

This paper deals with probe measurements of low frequency resistance (RLF), high frequency resistance (RHF), and resistance index (= 100 x RLF/RHF), for the determination of cold hardiness or the injury caused by cold treatments. Populations of white clover (Trifolium repens L.) were subjected to different periods of freezing. Discrimination between treatments could be made in terms of RLF, RHF, and resistance index, though discrimination in terms of RHF is poor. The rest of the paper deals with lucerne (Medicago sativa L.). Measurements were made after a cold treatment on field plants consisting of four commercial strains and their F1 crosses, and also on F2 seedlings. RLF and the resistance index appear to be equally good predictors for the recovery of strains or of individual plants from such populations. The Appendix deals with measurements on commercial (tetraploid) plants, diploids, and colchicine-produced tetraploids.

Dehydrin variants associated with superior freezing tolerance in alfalfa (Medicago sativa L.)

2009 ◽  
Vol 120 (6) ◽  
pp. 1163-1174 ◽  
Author(s):  
Wilfried Rémus-Borel ◽  
Yves Castonguay ◽  
Jean Cloutier ◽  
Réal Michaud ◽  
Annick Bertrand ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Freezing Tolerance ◽  
Medicago Sativa L

Effects of stand age on agronomic, morphological and chemical characteristics of alfalfa

1991 ◽  
Vol 71 (2) ◽  
pp. 445-452 ◽  
Author(s):  
Michio Suzuki
Keyword(s):  
Medicago Sativa ◽  
Cold Hardiness ◽  
Plant Density ◽  
Age Groups ◽  
Stand Age ◽  
Chemical Characteristics ◽  
Total Nonstructural Carbohydrates ◽  
Vertical Extension ◽  
Shoot Number ◽  
Medicago Sativa L

Iroquois alfalfa (Medicago sativa L.) was seeded every spring from 1978 to 1988, and the established stands were maintained until the fall of 1988. Agronomic, morphological and chemical characteristics of the stands were compared among different age groups. A drastic reduction of alfalfa population occurred in the seeding year and during the first winter. There were about 40 plants m−2 in the 2nd yr which gradually decreased to 25 plants m−2 in the 8th yr, and between 12 and 24 plants m−2 in the 10th yr. There were more grass weeds in older stands. Total dry matter yield of forage, including weeds, did not decrease significantly with age of alfalfa stand Alfalfa yield, however, decreased with age, and the reduction in older stands was more evident in cut 1 than cut 2. There was little or no difference in cold hardiness among different stand ages in postseeding years. Root development pattern changed from vertical extension in the seeding year to lateral development of branched roots in postseeding years. Shoot number, crown diameter, crown decay taproot diameter, root depth, and number and spread of branched roots were associated with aging. Concentrations of total nonstructural carbohydrates (TNC) in the crown and roots decreased slightly with age. In the root, concentrations of K, Ca, B, and Fe increased, and Ca was most closely associated with age. No significant association of P, Mg, S, Mn, Cu, or Zn with age was found. Concentrations of minerals in the crown did not change with age, except B which increased slightly. Key words: Medicago sativa L., persistence, longevity, plant density, yield, minerals

FALL GROWTH AND WINTER SURVIVAL OF ALFALFA IN INTERIOR BRITISH COLUMBIA

1989 ◽  
Vol 69 (2) ◽  
pp. 491-499 ◽  
Author(s):  
DARRYL G. STOUT ◽  
JOHN W. HALL
Keyword(s):  
British Columbia ◽  
Low Temperature ◽  
Medicago Sativa ◽  
Cold Hardiness ◽  
Winter Survival ◽  
Temperature Growth ◽  
Usual Procedure ◽  
Medicago Sativa L ◽  
Selection Of ◽  
Fall Growth

Extensive winter injury, likely caused by cold damage, occurred in alfalfa (Medicago sativa L.) cultivar yield tests underway at Kamloops, British Columbia during the 1985–1986 winter. Fall yield of cultivars during the year of seeding was negatively correlated with their winter survival (r = − 0.92 in one trial with 20 cultivars or strains, and r = − 0.74 in a second study with 34 cultivars or strains). Use of fall yield to predict winter survival has the advantage over the usual procedure of measuring plant height in space-planted plots, in that both total annual yield and fall growth can be evaluated in a single study. This results in a major saving of costs. Six cultivar studies all revealed that in the interior of British Columbia spring-summer yield is positively correlated to fall yield (r = 0.24 to 0.72). For this reason, selection of a cultivar with low fall growth to obtain high winter survival is likely to result in selection of a cultivar with reduced spring-summer yield.Key words: Medicago sativa, alfalfa, low temperature growth, winter injury, cold hardiness

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