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.

The influence of light and diurnal freezing temperature on the cold hardiness of winter wheat seedlings

1974 ◽  
Vol 52 (12) ◽  
pp. 2539-2546 ◽  
Author(s):  
C. J. Andrews ◽  
M. K. Pomeroy ◽  
I. A. de la Roche
Keyword(s):  
Low Temperature ◽  
Winter Wheat ◽  
Filter Paper ◽  
Cold Hardiness ◽  
Freezing Temperature ◽  
Wheat Seedlings ◽  
Temperature Growth ◽  
Low Temperature Growth

Seedlings of winter wheat (Triticum aestivwn cv. Rideau and Cappelle Desprez) grown on moist filter paper in petri plates in dark at low temperature increased in cold hardiness, as measured by changes in the LD50 temperatures. Rideau attained an LD50 temperature of −12 °C after 5 weeks, Cappelle Desprez, −6 °C. Exposure to light delayed the maximum hardiness by 2 weeks and increased it by 6 °C in both cultivars. Exposure to diurnal freezing temperature increased hardiness of both cultivars in the dark, and in light when excessive dehydration was prevented.Greater cold hardiness of plants of both cultivars was attained in soil in light at low temperature as compared with those in petri plates. Exposure of plants to diurnal freezing temperature maintained a higher level of hardiness after the maximum at 7 weeks than continuous low temperature without freezing. Diurnal freezing during active low temperature growth in petri plates or in soil increased hardiness of Rideau seedlings to an apparent maximum of −18 °C.

Development and molecular cytogenetic identification of new winter wheat – winter barley (‘Martonvásári 9 kr1’ – ‘Igri’) disomic addition lines

Genome ◽  
2007 ◽  
Vol 50 (1) ◽  
pp. 43-50 ◽  
Author(s):  
É. Szakács ◽  
M. Molnár-Láng
Keyword(s):  
In Situ Hybridization ◽  
Winter Wheat ◽  
Fluorescent In Situ Hybridization ◽  
Triticum Aestivum L ◽  
Winter Barley ◽  
Addition Lines ◽  
Hordeum Vulgare L ◽  
Disomic Addition Lines ◽  
Simple Sequence

This paper describes a series of winter wheat – winter barley disomic addition lines developed from hybrids between winter wheat line Triticum aestivum L. ‘Martonvásári 9 kr1’ and the German 2-rowed winter barley cultivar Hordeum vulgare L. ‘Igri’. The barley chromosomes in a wheat background were identified from the fluorescent in situ hybridization (FISH) patterns obtained with various combinations of repetitive DNA probes: GAA–HvT01 and pTa71–HvT01. The disomic addition lines 2H, 3H, and 4H and the 1HS isochromosome were identified on the basis of a 2-colour FISH with the DNA probe pairs GAA–pAs1, GAA–HvT01, and pTa71–HvT01. Genomic in situ hybridization was used to confirm the presence of the barley chromosomes in the wheat genome. The identification of the barley chromosomes in the addition lines was further confirmed with simple-sequence repeat markers. The addition lines were also characterized morphologically.

Fructan in winter wheat, triticale, and fall rye cultivars of varying cold hardiness

1988 ◽  
Vol 66 (9) ◽  
pp. 1723-1728 ◽  
Author(s):  
Michio Suzuki ◽  
H. G. Nass
Keyword(s):  
Winter Wheat ◽  
Cold Hardiness ◽  
Wheat Cultivar ◽  
Degree Of Polymerization ◽  
Lethal Temperature ◽  
Winter Wheat Cultivar ◽  
Freezing Resistance ◽  
Winter Cereals ◽  
Opposite Trend ◽  
High Concentrations

Eight winter wheat, one triticale, and three fall rye cultivars with mean lethal temperature (LT50) values from −5.5 to −20.0 °C were harvested in late November and analyzed for fructans. Fructose, sucrose, and oligofructans with a degree of polymerization (DP) of 6 or lower were found in all cultivars. The concentration of DP 4 fructan was higher than that of DP 5 in winter wheat and triticale, while the opposite trend was found in fall rye. Fructans with a DP of 7 or higher (high DP fructans) were found at high concentrations in hardy winter wheat and fall rye. The high DP fructan was very low or negligible in the least hardy winter wheat cultivar 'Super X'. Fructans in winter cereals consisted mainly of inulin type with a β-2-1 linkage. The activity of phlein sucrase, which catalyzes synthesis of phlein, was much lower in winter cereals compared with phlein-rich grasses. It was concluded that high DP fructans of inulin type in basal top tissues of winter cereals were more closely associated with freezing resistance than low DP fructans.

Injury within the crown of winter wheat seedlings after freezing and icing stress

1985 ◽  
Vol 63 (3) ◽  
pp. 432-436 ◽  
Author(s):  
Karen K. Tanino ◽  
Bryan D. McKersie
Keyword(s):  
Winter Wheat ◽  
Cold Hardiness ◽  
Apical Meristem ◽  
Basal Area ◽  
Differential Sensitivity ◽  
Freezing Stress ◽  
Basal Region ◽  
Wheat Seedlings ◽  
Pattern Of Injury ◽  
Tetrazolium Staining

The cells in the crown of winter wheat cv. Fredrick critical for the survival of freezing and icing stress were identified using tetrazolium staining as a viability test. In acclimated seedlings, a freezing stress which lowered regrowth (−12 °C) also lowered tetrazolium staining in the vascular transition zone in the basal portion of the crown but generally did not affect the staining of the apical meristem. The majority of cells in the crown, including the apical meristem, were able to reduce tetrazolium after a lethal freezing stress. Thus, survival was limited by the freezing tolerance of a relatively small number of cells in the basal region of the crown. These observations were confirmed using plasmolysis and mitotic figures as alternative indicies of viability. No significant variability was observed among winter wheat cultivars. However, in seedlings not acclimated to freezing stress, there was quite a different pattern of injury. In these seedlings, the sensitivity of the apical and basal regions to freezing was similar. Thus, these two regions appeared to differentially acclimate and the cells of the apical meristem developed greater cold hardiness than that of the basal area. After a lethal icing stress, all regions within the crown were able to reduce tetrazolium, but the crown was unable to regrow. The ability to reduce tetrazolium was gradually lost during the regrowth period. Unlike freezing stress, no differential sensitivity was observed within the crown, and there was no variability among the cultivars of winter wheat examined.

Duration of hardening and cold hardiness in winter wheat

1979 ◽  
Vol 57 (14) ◽  
pp. 1511-1517 ◽  
Author(s):  
D. W. A. Roberts
Keyword(s):  
Winter Wheat ◽  
Cold Hardiness ◽  
Cold Resistance ◽  
Maximum Level ◽  
Late Winter ◽  
Carbohydrate Reserves ◽  
Stage Of Development ◽  
Temperature Regimes ◽  
Number Of Leaves ◽  
Additional Reason

Experiments in which winter wheat plants were exposed to two different controlled hardening-temperature regimes (constant 3 °C, and 5.5 °C (day): 3.5 °C (night)) for long periods (up to 15 weeks) indicate that cold hardiness changes with time.The cold hardiness in plants grown from seed at 3 °C drops rapidly immediately after moistening and reaches a minimum 2–3 weeks later. Hardiness then begins to increase and reaches a maximum that lasts approximately from the 7th to the 11th week of growth after which it slowly declines.The patterns of change in cold hardiness during growth at 3 °C, and 5.5 °C:3.5 °C were almost synchronous if hardiness was plotted against duration of hardening, but were not synchronous if hardiness was plotted against stage of development as measured by the number of leaves produced. A somewhat similar result was obtained if plants grown for 3 weeks at 21 °C before hardening were compared with plants grown from dry seeds under the same hardening conditions. These experiments show that duration of hardening is more important in determining the level of cold resistance and the ability of wheat to retain its cold resistance than is stage of development, as measured by the number of leaves produced at the time cold resistance is measured.When plants seeded outdoors in mid-September were transferred at various dates (0–30 weeks after seeding) during the fall or winter to standardized hardening conditions in a growth cabinet for 0–15 weeks before freezing, their cold resistance changed in a way that suggests that plants in the field undergo the same pattern of changes in cold resistance as plants reared continuously in a growth chamber. This result suggests that the long exposure to hardening temperatures is one of the reasons why wheat in the field has less cold resistance in late winter than in autumn. Loss of carbohydrate reserves during winter may be an additional reason for this phenomenon.Under both growth cabinet and field conditions, increasing cold hardiness coincided with vernalization. Maximum cold hardiness was retained for several weeks after the completion of vernalization. These results suggest that the development of the maximum level of cold resistance may be related to the vernalization process.

DEHARDENING OF WINTER WHEAT AND RYE UNDER SPRING FIELD CONDITIONS

1977 ◽  
Vol 57 (4) ◽  
pp. 1049-1054 ◽  
Author(s):  
D. B. FOWLER ◽  
L. V. GUSTA
Keyword(s):  
Moisture Content ◽  
Winter Wheat ◽  
Cold Hardiness ◽  
Dry Weight ◽  
Test Site ◽  
Triticum Aestivum L ◽  
Winter Rye ◽  
Fresh Weight ◽  
Seeding Date ◽  
Secale Cereale L

Changes in cold hardiness (LT50), fresh weight, dry weight and moisture content were measured on crowns of winter wheat (Triticum aestivum L.) and rye (Secale cereale L.) taken from the field at weekly intervals in the spring of 1973 and 1974 at Saskatoon, Sask. In all trials, Frontier rye came out of the winter with superior cold hardiness and maintained a higher level of hardiness during most of the dehardening period. For cultivars of both species, rapid dehardening did not occur until the ground temperature at crown depth remained above 5 C for several days. Changes in crown moisture content tended to increase during dehardening. Over this same period crown dry weight increased for winter rye but did not show a consistent pattern of change for winter wheat. Two test sites were utilized in 1974. One site was protected by trees and the other was exposed. General patterns of dehardening were similar for these two sites, but cultivar winter field survival potentials were reflected only by LT50 ratings for the exposed test site. The influence of fall seeding date on spring dehardening was also investigated. Late-seeded wheat plots did not survive the winter in all trials. However, where there was winter survival, no differences in rate of dehardening due to seeding date were observed.

Ultrastructural changes in shoot apex cells of winter wheat seedlings during ice encasement

1978 ◽  
Vol 56 (7) ◽  
pp. 786-794 ◽  
Author(s):  
M. Keith Pomeroy ◽  
Chris J. Andrews
Keyword(s):  
Endoplasmic Reticulum ◽  
Winter Wheat ◽  
Structural Integrity ◽  
Triticum Aestivum L ◽  
Ultrastructural Changes ◽  
Wheat Seedlings ◽  
Contrast Exposure ◽  
Ice Encasement ◽  
Cold Hardy ◽  
Cellular Organelles

The decline in viability of cold-hardy Kharkov winter wheat (Triticum aestivum L.) seedlings during ice encasement at −1 °C was accompanied by characteristic ultrastructural changes. A dramatic increase in endoplasmic reticulum was observed within a few days. This proliferation of endoplasmic reticulum often resulted in the formation of an elaborate series of parallel membranes, either dispersed randomly throughout the cytoplasm or in the form of concentric whorls. However, the structural integrity of many cellular organelles was largely unaffected even by prolonged ice encasement resulting in death of the plants. In contrast, exposure of cold-hardy seedlings to near lethal, subfreezing temperature resulted in severe disorganization of cellular organelles. Ice encasement of nonhardened seedlings resulted in complete kill within 4 h. After 16 h ice encasement, occasional concentric whorls of endoplasmic reticulum and copious amounts of osmiophilic material were observed in the cytoplasm. Upon removal of the ice encasement stress, the accumulated endoplasmic reticulum disappeared rapidly during recovery at either2 or20 °C.

EFFECT OF PHENOXY HERBICIDES ON COLD HARDINESS OF WINTER WHEAT

1979 ◽  
Vol 59 (1) ◽  
pp. 237-240 ◽  
Author(s):  
S. FREYMAN ◽  
W. M. HAMMAN
Keyword(s):  
Winter Wheat ◽  
Cold Hardiness ◽  
Triticum Aestivum L ◽  
Controlled Environment ◽  
Minor Effect ◽  
Active Growth ◽  
Phenoxy Herbicides ◽  
Freezing Test ◽  
Environment Experiment ◽  
A Minor

In a controlled environment experiment, five phenoxy herbicides were sprayed at two rates on 14-day-old winter wheat (Triticum aestivum L. emend Thell ’Norstar’). After 7 additional days of active growth, the plants were cold-hardened for 14 days and then subjected to a freezing test. Four of the herbicides — MCPA amine, 2,4-D ester, 2,4-DB, 2,4-D amine — significantly reduced the cold hardiness of winter wheat whereas diclofop methyl had a minor effect. The reduction in hardiness was greater at the higher rates of application than at the lower rates.

Insect Distribution in a Spring Pea-Winter Wheat-Spring Barley Crop Rotation System

2000 ◽  
Vol 35 (3) ◽  
pp. 327-333 ◽  
Author(s):  
S. S. Quisenberry ◽  
D. J. Schotzko ◽  
P. F. Lamb ◽  
F. L. Young
Keyword(s):  
Winter Wheat ◽  
Weed Management ◽  
Conservation Tillage ◽  
Spring Barley ◽  
Triticum Aestivum L ◽  
Hordeum Vulgare L ◽  
Management Level ◽  
Insect Distribution ◽  
Tillage Method ◽  
Pea Leaf Weevil

The effects of tillage method (conventional or conservative) and weed management level (recommended or minimum) on insect distribution in a wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and pea (Pisum sativum L.) rotation were studied. Aphids were the major insect species on winter wheat and spring barley, but were not of economic importance. Beneficial species impacted aphid population levels by maintaining their numbers below economic thresholds. Tillage method and weed management level had limited impact on aphid and beneficial insect populations. Pea leaf weevil (Sitonia lineatus [L.]) and pea weevil (Bruchus pisorum [L.]) populations reached economic injury levels in 1992; two insecticide applications were needed. Pea leaf weevil populations did not reach economic levels in 1993; however, pea weevil populations reached an economic level at flowering stage and an insecticide was applied. Pea leaf weevil populations were higher in conventional tillage plots compared with conservation tillage plots. Early-season insecticide applications suppressed beneficial insects in the pea plots.

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