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

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

1975 ◽  
Vol 55 (2) ◽  
pp. 529-535 ◽  
Author(s):  
M. K. POMEROY ◽  
C. J. ANDREWS ◽  
G. FEDAK

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.


1990 ◽  
Vol 68 (7) ◽  
pp. 1597-1601 ◽  
Author(s):  
John S. Taylor ◽  
Munjeet K. Bhalla ◽  
J. Mason Robertson ◽  
Lu J. Piening

During overwintering in a northern climate, winter wheat goes through a hardening process, followed by dehardening in late winter – early spring. This sequence of events may be partially controlled by changes in endogenous hormone levels. Crowns and leaf tissue from field grown winter wheat (Triticum aestivum L. cv. Norstar) seeded at the beginning of September were collected and freeze-dried at monthly intervals during the winters of 1985–1986 and 1986–1987. Material was also sampled and freeze-dried from seedlings grown in a growth chamber under hardening conditions (21 °C for 2 weeks plus 3 °C for 6 weeks) or nonhardening conditions (3 weeks at 21 °C). The tissues were analysed for cytokinins and abscisic acid. Cytokinin levels, measured with the soybean hypocotyl section assay, declined from October onwards and then rose to a peak in late winter (January and February, winter 1986–1987; February and March, winter 1985–1986), subsequently declining again. Abscisic acid, quantitated as the methyl ester by gas chromatography with an electron capture detector, increased in level from October to December, then decreased to a relatively low level between January and March. Hardened seedlings from the growth chamber contained significantly higher abscisic acid levels and significantly lower cytokinin levels than did the nonhardened seedlings. Key words: abscisic acid, cytokinins, hardening, Triticum aestivum, winter wheat.


1978 ◽  
Vol 56 (7) ◽  
pp. 786-794 ◽  
Author(s):  
M. Keith Pomeroy ◽  
Chris J. Andrews

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.


2021 ◽  
Vol 11 (1) ◽  
pp. 55-61
Author(s):  
T.O. Rozhkova ◽  
S.V. Stankevych ◽  
A.V. Matsyura

The microbiota of winter wheat seeds from the North-East of Ukraine was studied by a biological method. Its considerable variability is established over three years (2017–2019). The effect of the treatment agents on most microorganisms of wheat seed microbiota in Ukraine, rather than on its genera and species, is shown. It has been proven that fungicides deleted some species and did not affect the development of others. Chemicals replaced some species or genera of fungi with others or even other microorganisms. Biological seed treatment (Phytosporin-M) has caused less microbiota change than chemical treatment (Maxim 0.25 FS, Rostock, Kinto Duo). Fungicides have replaced the dominance of Alternaria spp. (2017 – 57.8%, 2018 – 63.5%) for the dominance of yeast (Rostock – 54%) and Aureobasidium pullulans (Maxim 0.25 FS – 84.2%) in 2017, bacteria (Maxim 0.25 FS – 72.3%, Rostock – 53.8%) – in 2018. A. pullulans dominated in the microbiota of winter wheat seeds in 2019. The highest amount of A. pullulans was noted for the treatment of seeds by Phytosporin-M (85.9%). The biological seed treatment reduced the amount of Nigrospora spp. and Alternaria spp. Several times (3 and 5, respectively), chemical agents did not give Nigrospora spp. germination reduced the amount of A. pullulans, Alternaria spp. in 2019. Maxim 0.25 FS, Rostock 50%, and Kinto Duo delayed seed germination and seedling development on agar medium and soil, whereas Phytosporin-M – on the contrary, promoted the growth of seedlings and significantly exceeded control.


1991 ◽  
Vol 69 (5-6) ◽  
pp. 383-391 ◽  
Author(s):  
Jean Danyluk ◽  
Eric Rassart ◽  
Fathey Sarhan

Translatable messenger RNAs expression was compared in cold- and heat-stressed winter wheat (Triticum aestivum L. 'Fredrick' and 'Norstar') and spring wheat (T. aestivum L. 'Glenlea'). Polyadenylated RNA isolated from the crown and leaf tissues was translated in a wheat germ cell free system and the acidic and basic in vitro products were resolved by two-dimensional SDS–PAGE and autoradiography. The results showed that low temperature stress rapidly induced two groups of mRNAs. The first group was transient in nature and consists of 18 mRNAs that reached their highest levels of induction after 24 h of low temperature exposure and then decreased to undetectable levels. The second group consists of 53 mRNAs that were also induced or increased rapidly, but maintained their levels of expression during the 4 weeks required to induce freezing tolerance. Among those, at least 34 were expressed at higher levels in the freezing tolerant winter wheat compared with the less tolerant spring wheat. This suggests a possible relation between the expression of these mRNAs and the capacity of each genotype to develop freezing tolerance. In the case of heat shock, 50 mRNAs were induced or increased after 3 h at 40 °C. Among these, the expression of only six mRNAs was altered in a similar manner in the three genotypes by both treatments. The remaining mRNAs code for typical heat shock proteins which are different from those induced by low temperature. None of these mRNAs has been associated with the development of freezing tolerance. These results suggest that heat and cold stress are controlled by different genetic systems.Key words: wheat, mRNAs, proteins, low temperature, heat stress.


Plant Disease ◽  
2016 ◽  
Vol 100 (2) ◽  
pp. 318-323 ◽  
Author(s):  
E. Byamukama ◽  
S. Tatineni ◽  
G. Hein ◽  
J. McMechan ◽  
S. N. Wegulo

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.


1986 ◽  
Vol 64 (9) ◽  
pp. 1972-1976 ◽  
Author(s):  
L. A. Hunt ◽  
Anne-Marie Chapleau

Primordia production and leaf emergence were investigated in winter wheat (Triticum aestivum L. em Thell.) and two related species, winter rye (Secale cereale L.) and winter triticale (× Triticosecale Wittmack), under field conditions in Southern Ontario, a region with a humid continental climate. Primordia initiation could be adequately described by a linear regression of primordia number on accumulated degree-days in the 1st year of study, 1981 – 1982. In the 2nd year, however, a linear relationship was noticed only in the late winter and early spring, with the rate of primordia production being distinctly lower earlier in the season. The rate of primordia initiation was faster in the ryes than in the wheats, a superiority which was associated with greater spikelet production. Triticale had an intermediate rate of primordia initiation but was closer to wheat in the timing of double ridge and terminal spikelet formation. Leaves emerged at a constant rate (degree-days base) which was similar in most of the cultivars.


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