Seasonal changes in wheat-grain quality associated with high temperatures during grain filling

1991 ◽  
Vol 42 (1) ◽  
pp. 21 ◽  
Author(s):  
CS Blumenthal ◽  
IL Batey ◽  
F Bekes ◽  
CW Wrigley ◽  
EWR Barlow

Wheat plants exposed to higher than usual temperatures during ripening produced grain with weaker dough properties in glasshouse, field experiments and crop samples. In a review of Prime Hard wheat samples from 1960/61 to 1988/89, those seasons when the dough properties were particularly weak coincided with the years when the number of hours over 35�C during the grain filling period (October to December) was greatest. A five-day period of heat stress in 1988 provided an opportunity to directly investigate the effects of heat stress in the field. A weakening of dough properties was shown, for four varieties, by longer dough development times and faster breakdown in the Farinograph and also by shorter resistance to extension (at 5 cm) in the Extensograph. These (and similar changes for glasshouse grown grain) were accompanied by an increase in the proportion of gliadin (monomeric) proteins. That this increase was associated with the heat stress was shown by demonstrating increased accumulation of 14C amino acids into the gliadin fraction for heat-stressed heads in culture. These results support the hypothesis that episodes of high temperature during grain filling activate the heat shock elements of gliadin genes in wheat causing the mature grain to contain more gliadin and thus to produce weaker doughs.

1991 ◽  
Vol 42 (3) ◽  
pp. 325 ◽  
Author(s):  
CS Blumenthal ◽  
F Bekes ◽  
IL Batey ◽  
CW Wrigley ◽  
HJ Moss ◽  
...  

Grain quality results for variety trials extending over 27 years (3 sites and 5 varieties) were compared with the temperature profiles during the grain filling period (56 days prior to harvest) to determine the effects on quality of high temperatures (>35�C) during this period of growth. Heat stress episodes have been frequent at two (Narrabri, N.S.W., and Turretfield, S.A.) of the three sites studied; spring temperatures were more moderate at the third site, Wongan Hills, W.A. There were highly significant (P< 0.01) correlations of heat stress (as hours above 35�C, during grain filling) with protein content (positive) and with grain yields (negative) at Narrabri for all varieties. In many combinations of site and variety, heat stress correlated negatively with loaf volume, and with dough strength (as Rmax, resistance to stretching with the Extensograph). Heat stress episodes in the Narrabri (N.S.W.) region in 1981 and 1982 gave further opportunity to examine these relationships. Results showed very clearly that high temperatures late in grain filling were associated with weaker dough properties (lower Rmax) in the resulting grain. These trends may form the basis of a predictive system by which to estimate crop quality and to interpret the results of variety trials.


1996 ◽  
Vol 23 (6) ◽  
pp. 739 ◽  
Author(s):  
PJ Stone ◽  
ME Nicolas

Short periods of very high temperature (> 35�C) are common during the grain filling period of wheat, and can significantly alter mature protein composition and consequently grain quality. This study was designed to determine the stage of grain growth at which fractional protein accumulation is most sensitive to a short heat stress, and to examine whether varietal differences in heat tolerance are expressed consistently throughout the grain filling period. Two varieties of wheat differing in heat tolerance (cvv. Egret and Oxley, tolerant and sensitive, respectively) were exposed to a short (5 day) period of very high temperature (40�C max, for 6 h each day) at 5-day intervals throughout grain filling, from 15 to 50 days after anthesis. Grain samples were taken throughout grain growth and analysed for protein content and composition (albumin/globulin, monomer, SDS-soluble polymer and SDS-insoluble polymer) using size-exclusion high-performance liquid chromatography. The timing of heat stress exerted a significant influence on the accumulation of total wheat protein and its fractions, and protein fractions differed in their responses to the timing of heat stress. Furthermore, wheat genotype influenced both the sensitivity of fractional protein accumulation to heat stress and the stage during grain filling at which maximum sensitivity to heat stress occurred.


2020 ◽  
Vol 15 (1) ◽  
pp. 79-88
Author(s):  
Yu. A. Gulyanov ◽  
A. A. Chibilyov ◽  
A. A. Chibilyov Jr.

Aim. Verification of scientific concepts regarding the spatial heterogeneity of field agrocenoses. Identification of the variability of phytometric and structural crop ndicators and determination of the degree of their influence on the yield and quality of winter wheat grain in the steppe zone of the Orenburg Urals.Material and Methods. Establishment of field experiments, related observations and counts in accordance with the methodology of state variety crops testing and B.A.Dospekhov's guidelin. Monitoring of winter wheat crops was carried by measuring the vegetation index (NDVI) with a Green Seeker Handheld Crop Sensor, Model HCS‐100 (Trimble, USA). Determination of grain quality indicators was conducted according to GOST 9353‐2016 Wheat – Technical Conditions. Microsoft Office Excel was employed for the correlation and regression analysis of experimental data. Results. Analysis of the intra‐field heterogeneity of winter wheat agrocenoses in terms of yield and grain quality was conducted. The dependences of yield and grain quality on the principal crop phytometric and structural parameters were defined and expressed in the form of regression equations.Сonclusion. The results of the studies attest to the growth of reserves of grain yield to 3.0 t/ha and grain quality to class I‐II class in zonal climatic conditions of optimization of environmental factors to the level of the best basic plots by levelling out field soil heterogeneity. This is possible by restoring the fertility of anthropogenically‐degraded soil through the introduction of landscape‐adaptive and resource saving farming systems, soil protective and soil restorative crop rotation, differentiated application of organic and mineral fertilizers and selection of the most adaptive varieties. We also advise the introduction of intelligent ‘digital technologies’ aimed at fuller implementation of the genetic potential of cultivated varieties with careful consideration of natural resources and the preservation of biological diversity.


2008 ◽  
Vol 20 (4) ◽  
pp. 323-333 ◽  
Author(s):  
Ana S. Dias ◽  
Ana S. Bagulho ◽  
Fernando C. Lidon

The yield and grain quality (as well as technological traits) of two heat-stressed genotypes of bread (Triticum aestivum L.) and durum wheat (Triticum turgidum subsp. durum) having different tolerance to high temperatures after anthesis were investigated. Heat stress, during grain filling, triggered grain shrinkage with a reduced weight and ultrastructural changes in the aleurone layer and in the endosperm cells. Heat stress also decreased the sedimentation index SDS, an effect associated with increased protein content in the grain but with decreased levels of essential amino acids. Although the responses to heat stress were similar among the Triticum genotypes, it is further suggested that during grain filling, high temperatures might affect gluten strength, diminishing the wheat flour quality.


2012 ◽  
Vol 39 ◽  
pp. 62-70 ◽  
Author(s):  
David Gouache ◽  
Xavier Le Bris ◽  
Matthieu Bogard ◽  
Olivier Deudon ◽  
Christian Pagé ◽  
...  

1980 ◽  
Vol 7 (5) ◽  
pp. 519 ◽  
Author(s):  
EWR Barlow ◽  
JW Lee ◽  
R Munns ◽  
MG Smart

The physiological and anatomical mechanisms underlying the reduced sensitivity of wheat grain growth to water deficits in the post anthesis period have been investigated. The water potential (Ψ) and water content of the developing wheat grain and of other tissues within the wheat spike and flag leaf were compared under controlled environment and field conditions. In the 14 days following anthesis when the amount of water in each grain was increasing, the Ψ gradient between the grain and the rest of the plant was most pronounced. This Ψ gradient disappeared when the water per grain reached its maximum level (15 days after anthesis). The apparent turgor potential (P) of the wheat grain was very small (less than 0.2 MPa) throughout the grain filling period. When water was withheld 10 and 20 days after anthesis, the grain Ψ changed little despite a large decrease in the Ψ of the glumes, rachis and flag leaf. Grain Ψ showed the same independence during a diurnal cycle of water deficit. The independence of grain Ψ under water deficit conditions may be related initially to the xylem discontinuity in the floral axis and, in longer-term water stress situations, to the deposition of lipid in the pigment strand of the grain itself.


1999 ◽  
Vol 50 (3) ◽  
pp. 357 ◽  
Author(s):  
Roxana Savin ◽  
Marc E. Nicolas

In order to determine the importance of timing of short periods of high temperature and drought on grain weight and grain quality, a glasshouse experiment was carried out in which Schooner barley was exposed to short periods of heat stress (40˚C for 6 h/day for 5 consecutive days) or drought at early grain filling (10–15 days after anthesis, DAA), mid grain filling (20–25 DAA), or late grain filling (30–35 DAA). Individual grain weight was most sensitive to heat stress and drought treatments imposed early in grain filling and was less sensitive to later treatments. The reduction in grain weight was greater under heat stress (average 13%) than under drought in this study (average 6%). Starch was reduced in amount and quality, especially with early stresses during grain filling, but grain nitrogen percentage was similar between treatments.


1995 ◽  
Vol 22 (6) ◽  
pp. 927 ◽  
Author(s):  
PJ Stone ◽  
ME Nicolas

Short periods of very high temperature (> 35�C) are common in many of the world's wheat growing areas and can be a significant factor in reducing yield and quality of wheat. This study was designed to determine the stage at which grain growth is most sensitive to a short period of high temperature and to examine whether varietal differences in heat tolerance are expressed throughout the whole grain-filling period. Two varieties of wheat differing in heat tolerance (cvv. Egret and Oxley) were exposed to a short (5 days) period of very high temperature (40�C max. for 6 h each day) at 5-day intervals throughout grain filling, starting from 15 days after anthesis (DAA) and concluding at 50 DAA. Responses of grain dry matter accumulation and water content to high temperature were monitored throughout grain filling, and the results compared with controls maintained at 21/16�C day/night. Varietal differences in heat tolerance were expressed throughout the grain-filling period. Mature individual kernel mass was most sensitive to heat stress applied early in grain filling and became progressively less sensitive throughout grain filling, for both varieties. Reductions in mature kernel mass resulted primarily from reductions in duration rather than rate of grain filling.


Crop Science ◽  
2019 ◽  
Vol 59 (1) ◽  
pp. 318-332 ◽  
Author(s):  
Luis I. Mayer ◽  
Alfredo G. Cirilo ◽  
Gustavo A. Maddonni

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