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.

Influence de la température et de la durée d'un traitement cryoprotecteur sur la résistance au froid de plantules de blé. Étude ultrastructurale des ébauches foliaires

1983 ◽  
Vol 61 (4) ◽  
pp. 1025-1039 ◽  
Author(s):  
C. M. Gazeau
Keyword(s):  
Endoplasmic Reticulum ◽  
Treatment Period ◽  
Day Treatment ◽  
Leaf Primordia ◽  
Ultrastructural Changes ◽  
Distilled Water ◽  
Wheat Seedlings ◽  
Starch Grains ◽  
Different Temperatures ◽  
Protective Treatment

Wheat seedlings were treated at different temperatures and for various periods of time with a cold-protective substance, composed of a mixture of glycerol, dimethylsulfoxide, and saccharose. When the treatment was done at 20 °C, slight ultrastructural changes appeared in leaf primordia as soon as day 1. Thus numbers of lipid globules increased significantly. When the treatment period was increased to 4 days, numbers of starch grains increased, and there was a marked enlargement of mitochondria and plasts. When the treatment was done at 2 °C, cytoplasmic alterations occurred later than at 20 °C. After a 4-day treatment, they were similar to changes induced at 20 °C. When the treatment period was increased to 12 days, dictyosomes were markedly altered. They clustered close to the nucleus in two or three groups and gave rise to numerous pale vesicles with various shapes and sizes. Around each cluster of such vesicles, there gathered many endoplasmic reticulum vesicles and other organelles (mitochondria, plasts, microbodies, vacuoles). A further cooling of 1 °C/min, down to −15 or −30 °C, enhanced these phenomena. After the seedlings were warmed up to 20 °C in distilled water, the changes induced by the frost-protective treatment and then by freezing were shown to be reversible. [Journal translation]

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 MINERAL NUTRITION ON THE EXPRESSION OF TRAITS ASSOCIATED WITH WINTERHARDINESS OF TWO WINTER WHEAT (Triticum aestivum L.) CULTIVARS

1990 ◽  
Vol 70 (2) ◽  
pp. 443-454 ◽  
Author(s):  
P. RICHARD HETHERINGTON ◽  
BRYAN D. McKERSIE ◽  
LISA C. KEELER
Keyword(s):  
Triticum Aestivum ◽  
Low Temperature ◽  
Moisture Content ◽  
Winter Wheat ◽  
Mineral Nutrition ◽  
Triticum Aestivum L ◽  
Relative Ranking ◽  
Acclimation Period ◽  
Ice Encasement ◽  
Nutrient Solutions

Two winter wheat (Triticum aestivum L.) cultivars, Fredrick and Norstar, which differ in their winterhardiness potential, were compared with regard to the effects of nitrogen (N), phosphorus (P) and potassium (K) application, during acclimation, on the expression of four traits associated with winterhardiness — freezing, ice-encasement, and low temperature flooding tolerances and crown moisture content. Modified Hoagland’s nutrient solutions containing five levels of each nutrient were applied to the seedlings during a 5-wk acclimation period at 2 °C, and subsequently the crowns were tested for their ability to survive varying intensities of the stress treatments. Increasing the level of applied N from 0, caused a reduction in the level of all stress tolerances. Increased P did not significantly alter the expression of freezing tolerance, but tended to increase tolerance of the anaerobic stresses, icing and low temperature flooding, to an optimum. Increased K had minimal effects on stress tolerance at the levels tested. Increased levels of each nutrient increased crown moisture content. The cultivar Norstar was consistently more tolerant of freezing and icing stress than Fredrick and this relative ranking was not influenced by mineral nutrition. However, the relative ranking for low temperature flooding tolerance varied depending on the nutrients provided to the seedlings. The results suggest that environmental and growth regulatory factors which influence the uptake of mineral nutrients would be expected to influence crown moisture content, and the expression of stress tolerance.Key words: Freezing, ice-encasement, flooding

The effect of light on development of the rosette growth habit of winter wheat

1984 ◽  
Vol 62 (4) ◽  
pp. 818-822 ◽  
Author(s):  
D. W. A. Roberts
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Plant Height ◽  
Growth Habit ◽  
Triticum Aestivum L ◽  
Plant Age ◽  
Continuous Increase ◽  
Light Supply ◽  
Cold Hardy ◽  
Effect Of Light

Young plants of the cold-hardy winter wheat (Triticum aestivum L. emend. Thell.) Kharkov 22 MC did not develop atypical prostrate or rosette growth habit unless light supply exceeded 350 klux∙h∙day−1. Prostrate habit developed under both short (10-h) and long (16-h or 24-h) photoperiods. Under a given photoperiod, expression of this trait intensified as light intensities increased. This finding was demonstrated in both field and growth-cabinet experiments. The degree of development of the rosette growth habit may be assessed by plotting plant height against plant age. Plants that develop typical rosettes decline in height when the rosettes develop whereas plants that remain erect show a continuous increase in height.

scholarly journals Incidence of Wheat streak mosaic virus, Triticum mosaic virus, and Wheat mosaic virus in Wheat Curl Mites Recovered from Maturing Winter Wheat Spikes

Plant Disease ◽  
2016 ◽  
Vol 100 (2) ◽  
pp. 318-323 ◽  
Author(s):  
E. Byamukama ◽  
S. Tatineni ◽  
G. Hein ◽  
J. McMechan ◽  
S. N. Wegulo
Keyword(s):  
Winter Wheat ◽  
Mosaic Virus ◽  
Great Plains ◽  
Triticum Aestivum L ◽  
The United States ◽  
Wheat Streak Mosaic Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Wheat Seedlings ◽  
Geographical Regions ◽  
Sticky Tape

Wheat curl mites (WCM; Aceria tosichella) transmit Wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV), and Wheat mosaic virus (WMoV) to wheat (Triticum aestivum L.) in the Great Plains region of the United States. These viruses can be detected in single, double, or triple combinations in leaf samples. Information on incidence of viruses in WCM at the end of the growing season is scant. The availability of this information can enhance our knowledge of the epidemiology of WCM-transmitted viruses. This research was conducted to determine the frequency of occurrence of WSMV, TriMV, and WMoV in WCM populations on field-collected maturing wheat spikes and to determine differences in WCM densities in three geographical regions (southeast, west-central, and panhandle) in Nebraska. Maturing wheat spikes were collected from 83 fields across Nebraska in 2011 and 2012. The spikes were placed in proximity to wheat seedlings (three- to four-leaf stage) in WCM-proof cages in a growth chamber and on sticky tape. WCM that moved off the drying wheat spikes in cages infested the wheat seedlings. WCM that moved off wheat spikes placed on sticky tape were trapped on the tape and were counted under a dissecting microscope. At 28 days after infestation, the wheat plants were tested for the presence of WSMV, TriMV, or WMoV using enzyme-linked immunosorbent assay and multiplex polymerase chain reaction. WSMV was the most predominant virus detected in wheat seedlings infested with WCM from field-collected spikes. Double (TriMV+WSMV or WMoV+WSMV) or triple (TriMV+ WMoV +WSMV) virus detections were more frequent (47%) than single detections (5%) of TriMV or WSMV. Overall, 81% of the wheat seedlings infested with WCM tested positive for at least one virus. No significant association (P > 0.05) was found between regions for WCM trapped on tape. These results suggest that WCM present on mature wheat spikes harbor multiple wheat viruses and may explain high virus incidence when direct movement of WCM into emerging winter wheat occurs in the fall.

scholarly journals Modulation of Physiological Stress Response of Triticum aestivum L. to Glyphosate by Brassinosteroid Application

Life ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1156
Author(s):  
Elena Shopova ◽  
Zornitsa Katerova ◽  
Liliana Brankova ◽  
Ljudmila Dimitrova ◽  
Iskren Sergiev ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Phenolic Compounds ◽  
Winter Wheat ◽  
Antioxidant Defense ◽  
Physiological Stress ◽  
Physiological Responses ◽  
Triticum Aestivum L ◽  
Guaiacol Peroxidase ◽  
Herbicide Application ◽  
Wheat Seedlings

The potential of brassinosteroids to modulate the physiological responses of winter wheat (Triticum aestivum L.) to herbicide stress was evaluated. Young winter wheat seedlings were treated with 24-epibrassinolide (EBL) and 24 h later were sprayed with glyphosate. The physiological responses of treated plants were assessed 14 days after herbicide application. Wheat growth was noticeably inhibited by glyphosate. The herbicide application significantly increased the content of the stress markers proline and malondialdehyde (MDA) evidencing oxidative damage. The content of phenolic compounds was decreased in the herbicide-treated plants. Slight activation of superoxide dismutase (SOD) and catalase (CAT) and considerable increase of glutathione reductase (GR) and guaiacol peroxidase (POX) activities were found. Increased POX and glutathione S-transferase (GST) activities were anticipated to be involved in herbicide detoxification. Conjugation with glutathione in herbicide-treated plants could explain the reduction of thiols suggesting unbalanced redox state. EBL application did not alter the plant growth but a moderate activation of antioxidant defense (POX, GR, and CAT activities and phenolic levels) and detoxifying enzyme GST was observed. The hormonal priming provoked a slight decrease in MDA and proline levels. The results demonstrate that EBL-pretreatment partly restored shoot growth and has a potential to mitigate the oxidative damages in glyphosate-treated plants through activation of the enzymatic antioxidant defense and increase of the phenolic compounds.

A COMPARISON OF COLD HARDINESS AND ICE ENCASEMENT TOLERANCE OF TIMOTHY GRASS AND WINTER WHEAT

1983 ◽  
Vol 63 (2) ◽  
pp. 429-435 ◽  
Author(s):  
C. J. ANDREWS ◽  
B. E. GUDLEIFSSON
Keyword(s):  
Low Temperature ◽  
Winter Wheat ◽  
Cold Hardiness ◽  
Triticum Aestivum L ◽  
Similar Rate ◽  
Phleum Pratense ◽  
Temperature Growth ◽  
Low Temperature Growth ◽  
Timothy Grass ◽  
Ice Encasement

In the falls of 1979 and 1980 Salvo timothy grass (Phleum pratense L.) showed cold hardiness similar to Norstar winter wheat (Triticum aestivum L.) but significantly greater hardiness than Fredrick winter wheat. Ice tolerance of Salvo, with LI50 values of 29 and 45 days in the 2 yr, was more than twice that of the wheats. In controlled environments, seedlings of three timothy cultivars showed relatively low cold hardiness, but about threefold greater ice tolerance than the wheats. An Icelandic timothy cultivar, Korpa, showed greater ice tolerance than the Norwegian Engmo, and the Canadian cultivar Salvo. Fredrick wheat, and Korpa timothy cold hardened at a similar rate for 4 wk, but Korpa continued to harden to − 18 °C up to 6 wk of low temperature growth. Korpa rapidly attained a high tolerance to ice encasement in 2 wk of low temperature growth while Fredrick attained relatively low ice tolerance reaching a maximum at 3 wk of growth. There is little association between cold and ice tolerance in timothy, and there is a major difference in the ice tolerances of timothy and winter wheat. This high ice tolerance is likely to be a major cause of the superior survival of timothy in conditions of high winter stress. Key. words: Triticum, Phleum, acclimation, resistance, low temperature, frost

COLD HARDINESS OF WINTER WHEAT TILLERS ACCLIMATED UNDER FIELD CONDITIONS

1983 ◽  
Vol 63 (4) ◽  
pp. 879-888 ◽  
Author(s):  
W. G. LEGGE ◽  
D. B. FOWLER ◽  
L. V. GUSTA
Keyword(s):  
Triticum Aestivum ◽  
Moisture Content ◽  
Winter Wheat ◽  
Cold Hardiness ◽  
Lethal Dose ◽  
Survival Rates ◽  
Dry Weight ◽  
Triticum Aestivum L ◽  
Control Treatment ◽  
Cold Hardy

The cold hardiness of tillers separated from the plant immediately before freezing (CTM) or left intact on the crown (ICM) was determined by artificial freeze tests on two sampling dates for four winter wheat (Triticum aestivum L.) cultivars acclimated in the field. Plants with 9 and 13 tillers excluding coleoptile tillers were selected in mid-October and at the end of October, respectively. No differences in lethal dose temperature (LT50) were detected among CTM or ICM tillers sampled in mid-October. The three youngest CTM tillers sampled at the end of October were less cold hardy than older tillers. However, younger CTM tillers did not survive the unfrozen control treatment as well as older tillers. ICM tillers sampled at the end of October had the same LT50 except for one of the older tillers. No correlation was found between either the moisture content or dry weight and the LT50 of tillers. Winter survival of tillers was evaluated for two cultivars in the spring. Tillers of intermediate age and two of the youngest tillers had the highest survival rates. Tiller regeneration from axillary buds rather than the apical meristem occurred following cold stress and was negatively correlated to tiller emergence date. It was concluded that differences in cold hardiness among tillers must be taken into consideration if tillers are utilized to estimate the LT50 of a plant.Key words: Cold hardiness, tillers, winter wheat, Triticum aestivum L., developmental stage, moisture content

Phosphorus and nitrogen effects on the freezing tolerance of Norstar winter wheat

1999 ◽  
Vol 79 (2) ◽  
pp. 191-195 ◽  
Author(s):  
L. V. Gusta ◽  
B. J. O'Connor ◽  
G. L. Lafond
Keyword(s):  
Winter Wheat ◽  
Freezing Tolerance ◽  
Triticum Aestivum L ◽  
Early Spring ◽  
P Fertilization ◽  
Wheat Seedlings ◽  
Insulating Layer ◽  
Previous Crop ◽  
Late Fall ◽  
Growth Of Seedlings

To increase the probability of winter survival, it is recommended that winter wheat (Triticum aestivum L.) be sown into standing stubble from a previous crop, which acts to trap an insulating layer of snow. Therefore, to replenish nutrients used by the previous crop and to obtain optimum yields of winter wheat, these soils have to be fertilized with N and P. The objective of this study was to determine the effect of N and P, alone and in combination, on the freezing tolerance of Norstar winter-wheat seedlings in the fall and in early spring and during storage at −4 °C throughout the winter months. None of the fertilizer treatments had an effect on the freezing tolerance of the seedlings in late fall, however, P in combination with N decreased freezing tolerance in March and April, with the effects being more pronounced at high rates of P. Seedlings sampled from the field in early May were similar in freezing tolerance, irrespective of the level of fall-applied N and P. Both shoot and root growth of seedlings collected in the spring were enhanced by P fertilization in combination with N. Fall-applied P increased the level of tissue N and P, while applications of N increased the level of tissue N of seedlings sampled in late fall. Key words: Winter wheat, nitrogen, phosphorous, freezing tolerance

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