Grain growth and malting quality of barley. 2. Effects of temperature regime before heat stress

1997 ◽  
Vol 48 (5) ◽  
pp. 625 ◽  
Author(s):  
Roxana Savin ◽  
Peter J. Stone ◽  
Marc E. Nicolas ◽  
Ian F. Wardlaw
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Grain Growth ◽  
Gradual Increase ◽  
Grain Weight ◽  
Malting Quality ◽  
Yield And Quality ◽  
Grain Yield And Quality ◽  
Very High

Short periods of very high maximum temperature (>35°C) during grain filling appear to reduce grain yield and quality in barley. Tolerance of grain yield and quality to heat stress may be increased when acclimation to high temperature occurs. Two experiments were performed to test the hypothesis that a gradual (or stepped) increase to very high temperature reduces the impact of that stress on grain growth and quality of barley, compared with a sudden increase over the same temperature range. Plants experiencing either a sudden or a gradual increase did not exhibit any differences in grain weight or malting quality, but increasing the temperature in 2 steps (so that plants were exposed to 30 or 34°C for 2 h before a 40°C heat stress) appeared to have produced acclimation, since the reduction in grain weight under the 2-step treatment was about half that of either a sudden or gradual increase in temperature. Heat stress altered grain composition in various ways. The reduction in final grain weight was strongly and linearly related to the reduction in starch content. Grain β-glucan was 4·5 ± 0·5% across treatments and experiments and was significantly reduced in the glasshouse but not in the phytotron experiment. However, β-glucan degradation was similar between treatments in both experiments. Grain nitrogen concentration was very high and similar between treatments. Consequently, diastatic power was high and there was a trend towards a reduction under heat stress. Free amino nitrogen was higher under heat stress, indicating a higher protein modification than in the controls. Malt extract was significantly reduced by heat stress in the glasshouse experiment.

Grain growth and malting quality of barley. 1. Effects of heat stress and moderately high temperature

1997 ◽  
Vol 48 (5) ◽  
pp. 615 ◽  
Author(s):  
Roxana Savin ◽  
Peter J. Stone ◽  
Marc E. Nicolas ◽  
Ian F. Wardlaw
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Grain Growth ◽  
High Temperatures ◽  
Grain Filling ◽  
Grain Weight ◽  
Malting Quality ◽  
Very High ◽  
Moderately High Temperature

In this study, controlled-environment conditions were used to compare the effects of moderately high and very high temperatures during grain filling on grain growth and malting quality of barley. Heat stress applied from 15 to 20 days after anthesis (DAA) reduced grain weight by about 35%, whereas longer periods (15–20 days) of moderately high temperature applied from 20 DAA to maturity reduced grain weight by about 6%. Both heat stress and moderately high temperature resulted in reduced grain weight through a reduction in the duration of grain filling. Grain composition was altered by both moderately high and very high temperatures, although the changes were larger under very high temperatures. In general, there was a decrease in starch content, resulting from the reduction in both volume and number of A- and B-type starch granules. Nitrogen concentration was significantly increased only in the 30/25°C treatments, and changes in diastatic power were only minor. There was a reduction in β-glucan content, together with an increase in β-glucan degradation. However, malt extract was not significantly affected by these stresses.

Responses of grain growth and malting quality of barley to short periods of high temperature in field studies using portable chambers

1996 ◽  
Vol 47 (3) ◽  
pp. 465 ◽  
Author(s):  
R Savin ◽  
PJ Stone ◽  
ME Nicolas
Keyword(s):  
High Temperature ◽  
Grain Yield ◽  
Environmental Conditions ◽  
Grain Filling ◽  
Malting Quality ◽  
Malt Extract ◽  
Yield And Quality ◽  
Grain Yield And Quality ◽  
Days After Anthesis

Although environmental conditions during grain filling are often cited as the reason for decreases in malting quality of barley, little is actually known about the specific effects of different environmental conditions on grain yield and quality of barley. In the present study, an attempt was made to assess in the field the effects of short periods of high temperature (>35�C), using portable chambers with thermostatically controlled electric heaters, on grain yield and quality of barley. Two experiments were carried out in 2 consecutive years, involving the malting barley cultivars Schooner (first year) and Parwan (second year). The treatments were (i) control (no chamber, no heating) during the whole grain-filling period, (ii) plots with chambers heated to ca. 40�C for 6 h per day over 5 days starting 17 days after anthesis, and (iii) plots with non-heated chambers for 5 days from 17 days after anthesis. High temperature treatments reduced individual grain weight by 14% in Schooner and 25% in Parwan. There was a reduction in starch content and an increase in nitrogen content in the heat treatments compared to the control, but the G-glucan content was similar to the control. The resulting malt extract was reduced from 79 to 73% in Schooner and from 68.4 to 66.2% in Parwan in ,the heat stress treatment. The starch granule size distribution was also measured. Results indicate that decreases in grain dry matter were due to reductions in number rather than size of starch granules. It is concluded that high temperature reduced the amount of 'maltable' grain by reducing grain size and increasing the screening percentage, and also reduced malt extract by 3-7%, which represents a large decrease for the malting industry.

Grain weight and malting quality in barley as affected by brief periods of increased spike temperature under field conditions

2002 ◽  
Vol 53 (11) ◽  
pp. 1219 ◽  
Author(s):  
Valeria S. Passarella ◽  
Roxana Savin ◽  
Gustavo A. Slafer
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
High Temperatures ◽  
Grain Filling ◽  
Grain Weight ◽  
Malting Quality ◽  
Malt Extract ◽  
Yield And Quality ◽  
Grain Nitrogen ◽  
Nitrogen Percentage

High temperature is usually one of the most important stresses during grain filling affecting both yield and quality in barley crops. In the present study, an attempt was made to assess in the field the effects of short periods of high temperature, using transparent boxes covering only the spikes, with thermostatically controlled electric resistance for increasing the temperature. Treatments consisted of 2 malting cultivars and 5 heat treatments of high temperatures (8�C above the environmental temperature for 6 h/day for 5 consecutive days) over different periods during grain filling. Final grain weight was reduced by 2–14%, depending on the timing of heat stress and the genotype. There was a significant increase in grain nitrogen percentage in both cultivars, and grain β-glucans decreased with high temperatures in Logan and were unchanged in Beka. The resulting malt extract was reduced with exposure to high temperatures, depending on the cultivar, implying that even mild heat stress may change malting performance.

Effect of Timing of Heat Stress During Grain Filling on Two Wheat Varieties Differing in Heat Tolerance. II. Fractional Protein Accumulation

1996 ◽  
Vol 23 (6) ◽  
pp. 739 ◽  
Author(s):  
PJ Stone ◽  
ME Nicolas
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Grain Growth ◽  
Heat Tolerance ◽  
Grain Filling ◽  
Size Exclusion ◽  
Protein Accumulation ◽  
Wheat Varieties ◽  
Grain Filling Period ◽  
Very High

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.

Wheat Cultivars Vary Widely in Their Responses of Grain Yield and Quality to Short Periods of Post-Anthesis Heat Stress

1994 ◽  
Vol 21 (6) ◽  
pp. 887 ◽  
Author(s):  
PJ Stone ◽  
ME Nicolas
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Grain Yield ◽  
Amylose Content ◽  
High Temperature Treatment ◽  
Wheat Cultivars ◽  
Yield And Quality ◽  
Apparent Amylose Content ◽  
Wide Range ◽  
Grain Yield And Quality

Short periods of high temperature (> 35�C) are common during the post-anthesis period in Australian wheat crops and have recently been shown to significantly reduce grain yield and quality. In view of this, 75 cultivars of wheat were screened for tolerance to 3 days of high temperature (max. 40�C). Detailed results for grain yield and quality are presented for five wheat cultivars in order to illustrate the wide range of responses to short periods of high temperature. Individual kernel mass decreased by up to 23%, depending on variety, and the gliadin : glutenin ratio altered in the range -9 to +18% in response to high temperature treatment, also depending on variety. Noodle swelling power was significantly affected by heat in two cultivars, but there was no significant change due to heat in the apparent amylose content in any variety. The marked response of several yield and quality components to a heat treatment lasting only ca 5% of the grain-filling period suggests that starch and protein synthesis do not immediately andlor fully recover from short, severe heat stress. In addition, we conclude that wheat shows considerable genetic variability in tolerance to short periods of high temperature for both grain yield and quality.

Effects of Heat Stress at Different Grain-Filling Phases on the Grain Yield and Quality of Waxy Maize

2014 ◽  
Vol 91 (2) ◽  
pp. 189-194 ◽  
Author(s):  
Dalei Lu ◽  
Xuli Sun ◽  
Fabao Yan ◽  
Xin Wang ◽  
Renchao Xu ◽  
...  
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Grain Filling ◽  
Waxy Maize ◽  
Yield And Quality ◽  
Grain Yield And Quality

Effects of timing of heat stress and drought on growth and quality of barley grains

1999 ◽  
Vol 50 (3) ◽  
pp. 357 ◽  
Author(s):  
Roxana Savin ◽  
Marc E. Nicolas
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Grain Quality ◽  
Grain Filling ◽  
Grain Weight ◽  
Grain Nitrogen ◽  
Barley Grains ◽  
Nitrogen Percentage ◽  
Days After Anthesis

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.

Individual and combined effect of terminal drought and heat stress on allometric growth, grain yield and quality of bread wheat

2019 ◽  
Vol 52 (2) ◽  
Author(s):  
Abdul Sattar ◽  
Ahmad Sher ◽  
Muhammad Ijaz ◽  
Malik Saad Ullah ◽  
Niaz Ahmad ◽  
...  
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Bread Wheat ◽  
Combined Effect ◽  
Allometric Growth ◽  
Terminal Drought ◽  
Yield And Quality ◽  
Grain Yield And Quality ◽  
Drought And Heat Stress

Effect of Timing of Heat Stress During Grain Filling on Two Wheat Varieties Differing in Heat Tolerance. I. Grain Growth

1995 ◽  
Vol 22 (6) ◽  
pp. 927 ◽  
Author(s):  
PJ Stone ◽  
ME Nicolas
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Grain Growth ◽  
Heat Tolerance ◽  
Grain Filling ◽  
Dry Matter Accumulation ◽  
Varietal Differences ◽  
Short Period ◽  
Grain Filling Period ◽  
Very High

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.

scholarly journals Effects of field high temperature on grain yield and quality of a subtropical typejaponicarice—Pon-Lai rice

2016 ◽  
Vol 19 (1) ◽  
pp. 145-153 ◽  
Author(s):  
Yi-Chien Wu ◽  
Su-Jein Chang ◽  
Huu-Sheng Lur
Keyword(s):  
High Temperature ◽  
Grain Yield ◽  
Yield And Quality ◽  
Grain Yield And Quality
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