scholarly journals Effect of heat stress at anthesis on yield formation in winter wheat  

2017 ◽  
Vol 63 (No. 3) ◽  
pp. 139-144 ◽  
Author(s):  
Hlaváčová Marcela ◽  
Klem Karel ◽  
Smutná Pavlína ◽  
Škarpa Petr ◽  
Hlavinka Petr ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperatures ◽  
Wheat Yield ◽  
Weather Conditions ◽  
Similar Response ◽  
Thousand Grain Weight ◽  
Yield Parameters ◽  
Temperature Regimes ◽  
Response To Temperature ◽  
Yield Formation

Heat stress around anthesis is considered to have an increasing impact on wheat yield under the ongoing climate change. However, the effect of high temperatures and their duration on formation of individual yield parameters is still little understood. Within this study, the effect of high temperatures applied during anthesis for 3 and 7 days on yield formation parameters was analysed. The study was conducted in growth chambers under four temperature regimes (daily temperature maxima 26, 32, 35 and 38°C). In the periods preceding and following heat stress regimes the plants were cultivated under ambient weather conditions. The number of grains per spike was reduced under temperatures ≥ 35°C in cv. Bohemia and ≥ 38°C in cv. Tobak. This resulted in a similar response of spike productivity. Thousand grain weight showed no response to temperature regime in cv. Tobak, whereas in cv. Bohemia, a peak response to temperature with maximum at 35°C was observed. The duration of heat stress had only little effect on most yield formation parameters.  

Drought and high temperatures effect on yield and grain quality of purple-grain lines of spring soft wheat

Biomics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 254-273
Author(s):  
N.I. Rumyantseva ◽  
A.I. Valieva ◽  
A.N. Akulov ◽  
D-l. F. Askhadullin ◽  
D-r. F. Askhadullin ◽  
...  
Keyword(s):  
Protein Content ◽  
High Temperatures ◽  
Prolonged Exposure ◽  
Wheat Yield ◽  
Weather Conditions ◽  
Triticum Aestivum L ◽  
Grain Protein Content ◽  
Reproductive Period ◽  
Wheat Lines ◽  
The Impact

This paper was aimed at the impact of drought and high temperatures on the main stages of plant development, yield, grain protein content (GPC) and its composition as well as content of phenolic compounds (PC) and anthocyanins (AC), and antioxidant activity (AOA) of grain of two purple-grained lines (163 and 193) and drought-resistant white-grained cultivar (cv.) Khazine of soft spring wheat (Triticum aestivum L.) in growing seasons of 2015-2018 years. It has been shown that the impact of drought and high temperatures on the wheat yield is complex and depends on genotype resistance, on the strength/duration of stress factor action, and on the stage of plant reproductive development. The periods of sensitivity were booting, heading, flowering, and milky ripening. In 2018, prolonged exposure to high temperatures and drought, from the stage of booting to the milky ripening stage, led to a decrease in the yield of all genotypes, and also contributed to an increase in the Kjeldahl protein content and the fraction of non-extractable proteins in the grain. In 2016, drought during the reproductive period and high temperatures at the stage of milk ripening turned out to be more favorable for the formation of the yield compared to the weather conditions in 2018, they contributed to an increase in the fraction of non-extractable proteins in Khazine grain, but a decrease in the content of non-extractable proteins in the grain of purple wheat lines. A decrease in the weight of 1000 grains under drought conditions was observed only for line 163. It was shown that purple wheat lines did not differ significantly from the cv. Khazine in the total PC content, but they had a higher AOA, probably due to presence of ACs. Drought caused a decreased PC and AC content in the grain of line 163, but an increased PC and AC content in line 193, which correlated with decreasing or increasing of AOA. It was shown that purple lines have different resistance to drought, which, can be explained by the ability to activate biosynthesis of PC and, particularly, ACs with high AOA in response to impact of stressors.

Growth and Development of Five Populations of Themeda australis in Response to Temperature

1975 ◽  
Vol 23 (6) ◽  
pp. 951 ◽  
Author(s):  
RH Groves
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Growth And Development ◽  
Temperature Response ◽  
Morphological Characters ◽  
Photoperiodic Response ◽  
Ecological Significance ◽  
Temperature Regimes ◽  
Eastern Australia ◽  
Response To Temperature

Five populations of the widespread indigenous grass Themeda australis were selected from sites in south-eastern Australia with different temperature regimes. Differences between populations in some morphological characters are reported for plants grown in a uniform environment. In one experiment shoot and root temperatures were varied together: in a second, root tempera- ture only was varied and shoot temperature kept constant. Results of both experiments show that there were few significant differences between populations in the number of tillers per plant formed at the various temperatures. Deniliquin plants had the greatest leaf area of all populations. Time to anthesis differed between some populations and these differences could be related to the temperature regimes of the sites of origin. Plants from Tantangara, the coldest site, flowered first and uniformly at low temperatures, and plants from Deniliquin, where the summer (flowering) temperatures are highest, flowered last at low temperatures but first and uniformly at high temperatures. There were no differences between populations when mature post-flowering plants were subjected to low temperatures as radiation frosts but, when seedlings were frosted, the Adelaide Hills popula- tion from the most frost-free site was more frost-sensitive at - 6°C than all other populations. It is concluded that genetic differentiation of ecological significance within the taxon T. australis has occurred not only for the photoperiodic response reported previously but also for a temperature response to flowering. While no differentiation has been shown for growth at medium and high temperatures, a difference is reported in the ability of one population to withstand a minimal temperature of - 6° as frost.

scholarly journals Physiological responses and post-stress recovery in field-grown maize exposed to high temperatures at flowering

2019 ◽  
pp. 2053-2061
Author(s):  
Nicolás Neiff ◽  
Edmundo L. Ploschuk ◽  
Oscar R. Valentinuz ◽  
Fernando H. Andrade
Keyword(s):  
Heat Stress ◽  
High Temperatures ◽  
Cell Injury ◽  
Co2 Concentration ◽  
Physiological Traits ◽  
Maximum Efficiency ◽  
Maize Cultivars ◽  
Temperature Regimes ◽  
Internal Co2 ◽  
Heat Stress Tolerance

Heat stress affects physiological traits and biomass production in major crops, including maize. We researched the responses of maximum efficiency of photosystem II (Fv/Fm), relative cell injury (RCI), stomatal conductance (gs), internal CO2 concentration (Ci), leaf photosynthesis (CER), and crop growth rate (CGR) in two maize cultivars exposed to high temperatures around silking (R1) under field conditions. Temperature regimes (i.e. control and heat) were performed during the pre-silking (–15d R1 to R1) and post-silking (R1+2d to R1+17d) periods. In the heat treatments, polyethylene shelters were used in order to increase daytime temperatures around midday (from 10 A.M. to 2 P.M.) during each period (i.e., pre- and post-silking). In the control treatments, the shelters remained open during the entire growing season. Gas exchange variables, Fv/Fm and relative cell injury (RCI) were measured on ear leaves. CGR was estimated based on biomass samples. CER and Fv/Fm presented maximum reductions at the end of the daytime heating. However, 30 min after the shelters were reopened, Fv/Fm of heated leaves reached values similar to controls, which were closely linked to CER recoveries. RCI was negatively associated with Fv/Fm, and cell injury increased gradually as heating continued. Ci was unaffected by heat treatment, indicating that gs was not the primary cause of CER reduction. Heat stress decreased CGR, and the reduction was positively associated with CER and Fv/Fm in both heating periods. We attempted to scale from cell to crop level and identify some physiological traits that could be helpful in breeding programs for heat stress tolerance.

scholarly journals The impacts of increased heat stress events on wheat yield under climate change in China

2017 ◽  
Vol 140 (3-4) ◽  
pp. 605-620 ◽  
Author(s):  
Xuan Yang ◽  
Zhan Tian ◽  
Laixiang Sun ◽  
Baode Chen ◽  
Francesco N. Tubiello ◽  
...  
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Wheat Yield

scholarly journals THE ROLE OF FLAG LEAVES AND AWNS IN THE FORMATION OF WINTER WHEAT PRODUCTIVITY (REVIEW)

2018 ◽  
pp. 32-34 ◽  
Author(s):  
S. N. Gromova ◽  
P. I. Kostylev
Keyword(s):  
Winter Wheat ◽  
Leaf Surface ◽  
Wheat Yield ◽  
Complex Trait ◽  
Genetic System ◽  
Flag Leaves ◽  
Grain Productivity ◽  
Agricultural Yield ◽  
Yield Formation

The article presents the results of the conducted analysis of research works about the effect of size of flag leaves and awns on winter wheat productivity. The genetic potential of the variety, which can be realized on the basis of its biologic characteristics largely influences on its productivity. Productivity is a complex trait that is controlled by a complex genetic system closely connected with many factors of environment. The size and duration of assimilation surface are the most important components of biologic and agricultural yield of wheat. Many researchers showed that the amount and duration of photosynthesis by leaf surface are the main factors limiting productivity in the definite conditions of growing, and the size of leaf surface correlates with grain productivity. Photosynthetic parts of winter wheat include not only leaves, but also stems, heads, awns, etc. The conducted analysis of the literature showed that there is no consensus on the effect of flag leaves on wheat yield formation. Therefore it’s necessary to fulfill the study and evaluation of the part of flag leaves and awns in the formation of winter soft wheat productivity in the Rostov region.

scholarly journals Field-based investigation of aged biochar coupled with summer legumes effect on wheat yield in Pakistan

2020 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Hafeez Ur Rahim ◽  
Sajjad Ahmad ◽  
Zaid Khan ◽  
Muhammad Ayoub Khan
Keyword(s):  
Maximum Yield ◽  
Wheat Yield ◽  
Wheat Crop ◽  
Human Consumption ◽  
Thousand Grain Weight ◽  
Data Set ◽  
Different Types ◽  
Biological Yield ◽  
Soil Fertility Improvement

There is a debate about whether the aged biochar effect can increase the crop yield or not. Herein, a field-based experimental data set and analysis provide the information on the aged biochar effect coupled with summer legumes on the yield of subsequent wheat. Briefly, in summer 2016, three different types of legumes i.e. mungbean, sesbania, and cowpea were grown with the intention of grain for human consumption, green manuring for soil fertility improvement, and fodder for livestock consumption. A fallow was also adjusted in the experiment with the purpose of comparison. Biochar was added to each experimental plot in triplicates at the rate of 0, 5, and 10 tons ha-1. After the harvesting of legumes, the biomass of each sesbania treatment plot was mixed in the field while the biomass of mungbean and cowpea were removed from each respective plot. To investigate the aged biochar effect, the wheat crop was grown on the same field layout and design (randomized complete block) of legumes. The data analysis highlighted that significantly maximum grain yield (kg ha-1), biological yield (kg ha-1); thousand-grain weight (g), and straw yield (kg ha-1) were obtained in the plots mixed with sesbania. Regarding the aged biochar effect, maximum yield was obtained in the plots with 10 tons ha-1treatment dose. Additionally, the interaction of aged biochar coupled with legumes was non-significant. In conclusion, this work could prove that aged biochar coupled with summer legumes enhanced the yield of subsequent wheat on a sustainable basis due to its long-term numerous benefits to the soil-plant system.

scholarly journals Effect heat stress on subcellular localization of Ca2+ in tomato fruits

2014 ◽  
Vol 67 (3-4) ◽  
pp. 235-241 ◽  
Author(s):  
Grażyna Garbaczewska ◽  
Danuta Chołuj ◽  
Zofia Starck
Keyword(s):  
Heat Stress ◽  
Subcellular Localization ◽  
Calcium Content ◽  
Cell Ultrastructure ◽  
Water Soluble ◽  
Tomato Fruits ◽  
Temperature Regimes ◽  
Saturated Atmosphere ◽  
Experimental Treatments ◽  
Soluble Fractions

The aim of this paper was to compare the fruit cell ultrastructure and subcellular localization of Ca<sup>2+</sup> after heat stress with the use of the potassium antimonate method (Slocum and Roux 1982, Tretyn et al. 1992). The tomato plants Robin cv., relatively tolerant to heat stress, were grown under uncontrolled greenhouse conditions to the stage of fruiting. The plants were placed for 20h in two temperature regimes: 23<sup>o</sup>C (optimal temperature) or 40<sup>o</sup>C (heat stress) in darkness, under water vapour saturated atmosphere. Immediately after heat stress the fruits were harvested to estimate water soluble and insoluble calcium contents and subcellular localization of Ca<sup>2+</sup>. After heating the concentration of calcium in tomato fruits increased about twice. In both temperature treatments the water soluble fractions were lower than insoluble ones at smaller differences between insoluble and soluble fractions after heat stress. The shapes and localization of Ca<sup>2+</sup> detected with the use of potassium antimonate method show that in fruits of control plants the precipitates were numerous, small and of oval shape. They were dispersed in cytosol or adjoined to endoplasmic reticulum or to external membrane of chloroplast. In the fruit of heated plants the precipitates were irregular in shape, amorphous and singly dispersed in the cytosol. We observed also some cytological changes in the structure of membranes and organelles of the plants of both experimental treatments. The heat induced increase of calcium content and the changes in subcellular localization of Ca<sup>2+</sup> under heat stress suggest that calcium ions may be involved in avoiding heat injury. The problem requires more detailed further investigations.

Short-term effects of biochar on soil properties and wheat yield formation with meat bone meal and inorganic fertiliser on a boreal loamy sand

2014 ◽  
Vol 191 ◽  
pp. 108-116 ◽  
Author(s):  
Priit Tammeorg ◽  
Asko Simojoki ◽  
Pirjo Mäkelä ◽  
Frederick L. Stoddard ◽  
Laura Alakukku ◽  
...  
Keyword(s):  
Soil Properties ◽  
Wheat Yield ◽  
Loamy Sand ◽  
Bone Meal ◽  
Short Term ◽  
Inorganic Fertiliser ◽  
Yield Formation ◽  
Meat Bone Meal ◽  
Short Term Effects

Temperature-induced pupil movements in insect superposition eyes

2000 ◽  
Vol 203 (4) ◽  
pp. 685-692 ◽  
Author(s):  
P. Nordstrom ◽  
E.J. Warrant
Keyword(s):  
High Temperatures ◽  
Cydia Pomonella ◽  
Codling Moth ◽  
Light Level ◽  
Agrotis Segetum ◽  
Effect Of Temperature ◽  
Activation Temperature ◽  
Ambient Light Level ◽  
Wide Range ◽  
Response To Temperature

In this paper, we describe the hitherto largely overlooked effect of temperature on the pupil of insect compound eyes. In the turnip moth Agrotis segetum and in two other nocturnal insects with superposition eyes, the lacewing Euroleon nostras and the codling moth Cydia pomonella, the pupil not only opens and closes with changes in the ambient light level, as expected, but also with changes in temperature in the absence of light. In complete darkness, the pupil of A. segetum responds over a wide range of temperatures, with the pupillary pigments migrating to a light-adapted position when the animal is exposed to either low or high temperatures. At temperatures between 21.0 and 22.7 C, the pigments migrate to the fully dark-adapted position, resulting in an open pupil and maximal eye glow. Pupil closure at high temperatures shows two distinct thresholds: the first at 23.8+/−0.7 C and a second some degrees higher at 25.7+/−1.2 C (means +/− s.d., N=10). Temperatures exceeding the first threshold (the activation temperature, T(a)) initiate a closure of the pupil that is completed when the temperature exceeds the second threshold (the closure temperature, T(c)), which causes rapid and complete migration of pigment to the light-adapted position. All temperatures above T(a) affect the pupil, but only temperatures exceeding T(c) result in complete closure. Temperatures between T(a) and T(c) cause a slow, partial and rather unpredictable closure. The lacewing and the codling moth both show very similar responses to those of A. segetum, suggesting that this response to temperature is widespread in superposition eyes. The possibility that the ambient temperature could be used to pre-adapt the eye to different light intensities is discussed.

scholarly journals The potential value of seasonal forecasts in a changing climate in southern Africa

2014 ◽  
Vol 18 (4) ◽  
pp. 1525-1538 ◽  
Author(s):  
H. C. Winsemius ◽  
E. Dutra ◽  
F. A. Engelbrecht ◽  
E. Archer Van Garderen ◽  
F. Wetterhall ◽  
...  
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Southern Africa ◽  
Weather Conditions ◽  
Stress Conditions ◽  
Mitigation Measures ◽  
Seasonal Forecasts ◽  
Weather Forecasts ◽  
Dry Spells ◽  
The Future

Abstract. Subsistence farming in southern Africa is vulnerable to extreme weather conditions. The yield of rain-fed agriculture depends largely on rainfall-related factors such as total seasonal rainfall, anomalous onsets and lengths of the rainy season and the frequency of occurrence of dry spells. Livestock, in turn, may be seriously impacted by climatic stress with, for example, exceptionally hot days, affecting condition, reproduction, vulnerability to pests and pathogens and, ultimately, morbidity and mortality. Climate change may affect the frequency and severity of extreme weather conditions, impacting on the success of subsistence farming. A potentially interesting adaptation measure comprises the timely forecasting and warning of such extreme events, combined with mitigation measures that allow farmers to prepare for the event occurring. This paper investigates how the frequency of extreme events may change in the future due to climate change over southern Africa and, in more detail, the Limpopo Basin using a set of climate change projections from several regional climate model downscalings based on an extreme climate scenario. Furthermore, the paper assesses the predictability of these indicators by seasonal meteorological forecasts of the European Centre for Medium-Range Weather Forecasts (ECMWF) seasonal forecasting system. The focus is on the frequency of dry spells as well as the frequency of heat stress conditions expressed in the temperature heat index. In areas where their frequency of occurrence increases in the future and predictability is found, seasonal forecasts will gain importance in the future, as they can more often lead to informed decision-making to implement mitigation measures. The multi-model climate projections suggest that the frequency of dry spells is not likely to increase substantially, whereas there is a clear and coherent signal among the models of an increase in the frequency of heat stress conditions by the end of the century. The skill analysis of the seasonal forecast system demonstrates that there is a potential to adapt to this change by utilizing the weather forecasts, given that both indicators can be skilfully predicted for the December–February season, at least 2 months ahead of the wet season. This is particularly the case for predicting above-normal and below-normal conditions. The frequency of heat stress conditions shows better predictability than the frequency of dry spells. Although results are promising for end users on the ground, forecasts alone are insufficient to ensure appropriate response. Sufficient support for appropriate measures must be in place, and forecasts must be communicated in a context-specific, accessible and understandable format.

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