scholarly journals Effects of drought at different periods of wheat development on the leaf photosynthetic apparatus and productivity

2019 ◽  
Vol 10 (4) ◽  
pp. 406-414
Author(s):  
V. V. Morgun ◽  
O. O. Stasik ◽  
D. A. Kiriziy ◽  
O. G. Sokolovska-Sergiienko ◽  
N. M. Makharynska
Keyword(s):  
Soil Moisture ◽  
Chlorophyll Content ◽  
Stem Elongation ◽  
Flag Leaf ◽  
Photosynthetic Apparatus ◽  
Field Capacity ◽  
Crop Productivity ◽  
Drought Treatment ◽  
Drought Impact ◽  
Grain Productivity

The problem of drought impact on crop productivity is especially relevant for the leading cereal – wheat, since significant cultivation areas of this crop are located in risky farming zones. The aim of our studies was to compare the peculiarities of drought impact during the period of vegetative growth and reproductive development on the chlorophyll content, activity of chloroplast antioxidant enzymes, the rate of carbon dioxide gas exchange and transpiration as well as productivity of the wheat plants. The studies were carried out on bread winter wheat plants (Triticum aestivum L.) of the Astarta and Natalka varieties grown in a pot experiment. The plants were watered daily to maintain the soil moisture level in the pots in the range 70–60% of field capacity. Drought treatment involving decrease in soil moisture to 30% of the field capacity was applied to some of the plants at late stem elongation stage (BBCH 37-45) and to other plants at heading-anthesis (BBCH 59-65) while control plants were watered as usual. After 7 days of drought, the watering of treated plants was resumed to maintain the soil moisture at the level of control plants until the harvest. The penultimate leaf at the late stem elongation stage and flag leaf at the heading–anthesis period were used for measurements of photosynthetic apparatus response to drought. Plants of both varieties treated at stem elongation stage showed lower decline in the photosynthetic activity, chlorophyll content and grain productivity than those treated at heading-anthesis. The results obtained indicated that photosynthetic apparatus of wheat has a higher drought tolerance at the stem elongation stage than during the heading-anthesis stage. Furthermore, plants stressed at the stem elongation stage revealed better compensatory growth of lateral productive shoots due to superior supply of plants with assimilates after drought termination. Astarta variety had a more drought-tolerant photosynthetic apparatus and higher grain productivity in both well-watered and drought conditions as compared to Natalka variety. The differences between varieties were more contrasting when drought was applied at heading-anthesis.

scholarly journals Influence of drought on the photosynthetic apparatus activity, senescence rate, and productivity in wheat plants

2020 ◽  
Vol 52 (5) ◽  
pp. 371-387
Author(s):  
O.O. Stasik ◽  
Keyword(s):  
Soil Moisture ◽  
Antioxidant Defense ◽  
Flag Leaf ◽  
Photosynthetic Apparatus ◽  
Co2 Assimilation ◽  
Drought Period ◽  
Defense Systems ◽  
Drought Tolerant ◽  
Grain Productivity ◽  
Antioxidant Defense Systems

Effects of soil drought at flowering stage on the functional state of photosynthetic apparatus and chloroplast enzymatic antioxidant defense systems in flag leaf during reproductive period, and the productivity of winter wheat plants of high-protein Natalka variety and drought-tolerant Podolyanka variety were studied in pot experiment. Until flowering and for the control plants during the entire vegetation, the soil moisture content was maintained at a level of 60—70 % of field capacity (FC). Drought treatment (soil moisture 30 % FC) was applied for 7 days covering flowering—early kernel watery ripe period (BBCH 61—71). After that, watering of plants was resumed to a control level which was maintained until the end of the growing season. The estimation of the chlorophyll and Rubisco content, the chloroplast antioxidant enzymes activity, and the net CO2 assimilation and transpiration rates was carried out on flag leaves. The measurements were taken on the third day of watering cessation (the first day the soil moisture reached 30 % FC, BBCH 61), at the end of the drought period (seventh day at 30 % FC, BBCH 71), and after watering resumed at the medium milk (BBCH 75) and late milk (BBCH 77) stages. The components of plant grain productivity were determined by weighing air-dry material at grain full ripeness. It was revealed, that drought stress during flowering inhibited CO2 assimilation and accelerated induction of senescence processes in wheat plants associated with degradation of photosynthetic apparatus and manifested in quicker ontogenetic drop in chlorophyll and Rubisco contents and loss of leaf photosynthetic activity. This exacerbated the drought impact on the plant organism so that after optimal watering return, the physiological and biochemical parameters were not restored to the values of control plants that were all time under optimal moisture supply. Stress-induced premature senescence reduced the supply of plants with assimilates and ultimately led to a decrease in their grain productivity. Impact of drought on flag leaf photosynthetic activity and especially on senescence induction were much more pronounced in the high-protein wheat variety Natalka with a genetically programmed earlier start of the nitrogen-containing compounds remobilization from leaves than in Podolyanka variety. The drought-tolerant variety Podolyanka keep ability to maintain much higher CO2 assimilation activity during drought period and to preserve photosynthetic apparatus from early induction of senescence due to likely more efficient chloroplast antioxidant defense systems, thereby gaining a better assimilates supply for yield formation.

scholarly journals Are early foliar fungicide applications on durum wheat grown in southeast Saskatchewan beneficial in increasing grain productivity?

2014 ◽  
Vol 94 (5) ◽  
pp. 891-903 ◽  
Author(s):  
M. R. Fernandez ◽  
W. E. May ◽  
S. Chalmers ◽  
M. E. Savard ◽  
A. K. Singh
Keyword(s):  
Grain Yield ◽  
Durum Wheat ◽  
Stem Elongation ◽  
Flag Leaf ◽  
Kernel Weight ◽  
Growth Stages ◽  
Head Blight ◽  
Leaf Emergence ◽  
Grain Productivity ◽  
Foliar Fungicide

Fernandez, M. R., May, W. E., Chalmers, S., Savard, M. E. and Singh, A. K. 2014. Are early foliar fungicide applications on durum wheat grown in southeast Saskatchewan beneficial in increasing grain productivity? Can. J. Plant. Sci. 94: 891–903. Producers have expressed interest in applying fungicides early in the development of durum wheat to reduce disease severity and increase grain yield. To address this issue, a field trial was conducted in southeast Saskatchewan (2004–2006) to determine the impacts of single and double foliar fungicide (tebuconazole) applications at various growth stages on leaf spotting, Fusarium head blight/Fusarium-damaged kernels, deoxynivalenol concentration, dark kernel discolouration, and grain traits of durum wheat. In most cases, application at stem elongation was not effective in reducing Fusarium diseases, or improving yield and grain characteristics. Application at flag leaf emergence was more effective, but for the most part, application at anthesis resulted in the most consistent reduction in disease levels, and improvement in test weight. Double fungicide applications (stem elongation or flag leaf emergence, and anthesis) were not more effective in disease control than a single application at anthesis. Grain yield did not differ significantly among any of the treatments. In contrast to Fusarium diseases and leaf spotting, fungicide applications at stem elongation and/or flag leaf emergence resulted in increased kernel weight and percentage dark kernel discolouration, which was significant in 2005 (10.53–10.60% total kernel discolouration in the stem and flag leaf treatments vs. 6.13% for the untreated control). In one or more years, kernel weight was negatively associated with Fusarium disease variables and leaf spotting, but positively associated with kernel discolouration. We conclude that under variable environmental conditions in Saskatchewan, early preventative fungicide use on durum wheat should not be recommended as a strategy to improve productivity, and might even result in increases in dark kernel discolouration and grain downgrading.

scholarly journals Effect of drought on photosynthetic apparatus, activity of antioxidant enzymes, and productivity of modern winter wheat varieties

2019 ◽  
Vol 10 (1) ◽  
pp. 16-25 ◽  
Author(s):  
V. V. Morgun ◽  
O. O. Stasik ◽  
D. A. Kiriziy ◽  
O. G. Sokolovska-Sergiienko
Keyword(s):  
Antioxidant Enzymes ◽  
Soil Moisture ◽  
Drought Tolerance ◽  
Winter Wheat ◽  
Flag Leaf ◽  
Co2 Assimilation ◽  
Assimilation Rate ◽  
Wheat Varieties ◽  
Grain Productivity ◽  
Winter Wheat Varieties

The response of modern winter wheat varieties to soil drought was studied with aim of phenotyping their drought tolerance characteristics and identification of the most informative indices that may be suitable for use in breeding programs. Plants of winter bread wheat (Triticum aestivum L.) varieties Podolyanka, Khurtovyna, Vinnychanka and Prydniprovska were grown in a pot experiment. The soil moisture for control plants was maintained at a level of 70% of field capacity (FC) throughout the vegetative stage. At the flowering, watering of the treated plants was stopped to reduce the soil moisture to a level of 30% FC and then this soil moisture level was maintained for 10 days. After that, the irrigation of the treated plants was restored to the level of control. It was found that in the flag leaf under drought condition, the chlorophyll content, net CO2 assimilation rate, and transpiration rate decreased, while the leaf water deficit, the ratio of photorespiration to CO2 assimilation, and the activity of chloroplasts antioxidant enzymes (superoxide dismutase and ascorbate peroxidase) increased. The ten-day drought significantly reduced the grain yield from the plant. Calculations of the relative changes in the physiological parameters of treated plants as compared to the control were the most informative for the differentiation of varieties for drought tolerance. Relative changes in the content of chlorophyll in the flag leaf under drought and reduction in the total biomass of the plant closely correlated with a decrease in grain productivity (r = 0.92 and r = 0.96 respectively). There was also a significant correlation of grain productivity with a decrease in the NAR measured in the period of drought (r = 0.68). Therefore, the maintenance of the photosynthetic function of plants under conditions of insufficient water supply plays a determinant role in reducing the grain productivity losses. The relative changes in the chlorophyll content and CO2 assimilation rate in plants subjected to drought as compared to control may be used as markers of drought tolerance of genotypes for genetic improvement of wheat by conventional breeding and biotechnological methods.

scholarly journals Physiological Responses of Agriophyllum Squarrosum and Setaria Viridis to Drought and Re-watering

2021 ◽  
Author(s):  
Juanli Chen ◽  
Xueyong Zhao ◽  
Yuqiang Li ◽  
Yongqing Luo ◽  
Yaqiu Zhang ◽  
...  
Keyword(s):  
Membrane Permeability ◽  
Chlorophyll Content ◽  
Field Capacity ◽  
Membrane Lipid ◽  
Severe Drought ◽  
Setaria Viridis ◽  
Drought Treatment ◽  
Drought Duration ◽  
Drought Period ◽  
Agriophyllum Squarrosum

Abstract The drought resistance of psammophytes determines their survival and growth under natural conditions or after transplanting. However, their responses to drought are not well understood. Agriophyllum squarrosum is a pioneer psammophyte in Horqin sandy land’s vegetation community, and Setaria viridis is the climax species. We conducted a pot experiment with both species to study how their physiological characteristics respond to drought and rehydration. We found that watering to 60 and 65% of field capacity (the control) provided more water than was required by A. squarrosum, and its leaves became yellow and slightly wilted. The total chlorophyll content and Fm (maximum fluorescence after dark adaptation) were lower than in the drought treatment, and both decreased after rehydration. With increasing drought duration, the chlorophyll content and Fm of A. squarrosum under moderate and severe drought first increased and then decreased, malondialdehyde levels and membrane permeability increased, but the quantum efficiency of photosystem II (Fv/Fm) decreased. With increasing drought duration and intensity, the relative water content (RWC), chlorophyll content, Fm, and Fv/Fm of S. viridis decreased, but malondialdehyde levels and membrane permeability increased. During the late drought period, levels of A. squarrosum’s three antioxidant enzymes increased to prevent membrane lipid peroxidation; for S. viridis, only peroxidase and superoxide dismutase levels increased. After rehydration, RWC of both plants increased, but the chlorophyll content decreased. Fv/Fm of A. squarrosum and Fm of S. viridis did not recover after severe drought. Our results provide insights into psammophyte adaptation to drought stress to support ecological restoration and reconstruction.

scholarly journals Physiological responses of Agriophyllum squarrosum and Setaria viridis to drought and re-watering

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Juanli Chen ◽  
Xueyong Zhao ◽  
Yuqiang Li ◽  
Yongqing Luo ◽  
Yaqiu Zhang ◽  
...  
Keyword(s):  
Chlorophyll Content ◽  
Normal Growth ◽  
Field Capacity ◽  
Arid Environment ◽  
Membrane Lipid ◽  
Severe Drought ◽  
Setaria Viridis ◽  
Drought Treatment ◽  
Drought Duration ◽  
Agriophyllum Squarrosum

AbstractDrought resistance of psammophyte determines survival and growth, but their responses to drought are not well understood. We conducted a pot experiment to study how physiological characteristics respond to drought and rehydration. We found that watering to 60–65% of field capacity (the control) provided more water than was required by Agriophyllum squarrosum and its leaves became yellow and slightly wilted. The total chlorophyll content and Fm (maximum fluorescence after dark adaptation) in control were lower than in the drought treatment, and both decreased after rehydration. With increasing drought duration and intensity, the relative water content (RWC), chlorophyll content, Fm, and the quantum efficiency of photosystem II (Fv/Fm) of Setaria viridis decreased, but malondialdehyde and membrane permeability increased. During the late drought, the activities of three antioxidant enzymes in A. squarrosum increased to prevent membrane lipid peroxidation; for S. viridis, only peroxidase and superoxide dismutase activities increased. After rehydration, RWC of both species increased, but Fv/Fm of A. squarrosum and Fm of S. viridis did not recover under severe drought. Our research illustrated that A. squarrosum is better adapted to arid environment than S. viridis, but the high soil moisture content is not conducive to normal growth of A. squarrosum.

Soil Moisture Deficits in South-Central Sweden

1989 ◽  
Vol 20 (2) ◽  
pp. 109-122 ◽  
Author(s):  
Lotta Andersson
Keyword(s):  
Soil Moisture ◽  
Field Capacity ◽  
Interannual Variations ◽  
Neutron Probe ◽  
South Central ◽  
Normal Ranges ◽  
Moisture Fluxes ◽  
In The Beginning ◽  
Probe Measurements ◽  
Different Parts

Some commonly used assumptions about climatically induced soil moisture fluxes within years and between different parts of a region were challenged with the help of a conceptual soil moisture model. The model was optimised against neutron probe measurements from forest and grassland sites. Five 10 yrs and one 105 yrs long climatic records, from the province of Östergötland, situated in south-central Sweden, were used as driving variables. It was concluded that some of the tested assumptions should not be taken for granted. Among these were the beliefs that interannual variations of soil moisture contents can be neglected in the beginning of the hydrological year and that soils usually are filled up to field capacity after the autumn recharge. The calculated climatic induced dryness was estimated to be rather insensitive to the choice of climatic stations within the region. Monthly ranges of soil moisture deficits (1883-1987) were shown to be skewed and it is therefore recommended to use medians and standard deviations in statistical analyses of “normal” ranges of soil moisture deficits.

scholarly journals Abiotic Stress Response of Near-Isogenic Spring Durum Wheat Lines under Different Sowing Densities

2021 ◽  
Vol 22 (4) ◽  
pp. 2053
Author(s):  
Judit Bányai ◽  
Marco Maccaferri ◽  
László Láng ◽  
Marianna Mayer ◽  
Viola Tóth ◽  
...  
Keyword(s):  
Drought Stress ◽  
Durum Wheat ◽  
Chlorophyll Content ◽  
Vegetation Index ◽  
Flag Leaf ◽  
Kernel Weight ◽  
Grain Weight ◽  
Abiotic Stress Response ◽  
Grain Number ◽  
Isogenic Lines

A detailed study was made of changes in the plant development, morphology, physiology and yield biology of near-isogenic lines of spring durum wheat sown in the field with different plant densities in two consecutive years (2013–2014). An analysis was made of the drought tolerance of isogenic lines selected for yield QTLs (QYld.idw-2B and QYld.idw-3B), and the presence of QTL effects was examined in spring sowings. Comparisons were made of the traits of the isogenic pairs QYld.idw-3B++ and QYld.idw-3B−− both within and between the pairs. Changes in the polyamine content, antioxidant enzyme activity, chlorophyll content of the flag leaf and the normalized difference vegetation index (NDVI) of the plot were monitored in response to drought stress, and the relationship between these components and the yield was analyzed. In the case of moderate stress, differences between the NIL++ and NIL−− pairs appeared in the early dough stage, indicating that the QYld.idw-3B++ QTL region was able to maintain photosynthetic activity for a longer period, resulting in greater grain number and grain weight at the end of the growing period. The chlorophyll content of the flag leaf in phenophases Z77 and Z83 was significantly correlated with the grain number and grain weight of the main spike. The grain yield was greatly influenced by the treatment, while the genotype had a significant effect on the thousand-kernel weight and on the grain number and grain weight of the main spike. When the lines were compared in the non-irrigated treatment, significantly more grains and significantly higher grain weight were observed in the main spike in NIL++ lines, confirming the theory that the higher yields of the QYld.idw-3B++ lines when sown in spring and exposed to drought stress could be attributed to the positive effect of the “Kofa” QTL on chromosome 3B.

scholarly journals Improvement of the photosynthetic activity of Moldavian dragonhead (Dracocephalum moldavica L.) through foliar application of a nitrophenolate–based biostimulant

2018 ◽  
Vol 10 ◽  
pp. 01009
Author(s):  
Sławomir Kocira ◽  
Agnieszka Sujak ◽  
Tomasz Oniszczuk ◽  
Agnieszka Szparaga ◽  
Mariusz Szymanek ◽  
...  
Keyword(s):  
Chlorophyll Content ◽  
Photosynthetic Activity ◽  
Foliar Application ◽  
Positive Impact ◽  
Abiotic Stress Tolerance ◽  
Photosynthetic Apparatus ◽  
Nutrient Content ◽  
Physiological Processes ◽  
Naturally Occurring ◽  
Reported Study

Application of biostimulants instigates many physiological processes that enhance nutrition efficiency, abiotic stress tolerance, and quality traits of crops, regardless of their nutrient content. One of such preparations is Atonik which contains nitrophenol compounds naturally occurring in plant cells. Several studies have confirmed its beneficial effect on the growth, development, and improved metabolic activity of plants. Therefore, it seems advisable to investigate the effect of Atonik preparation on the photosynthetic activity of Moldavian dragonhead (Dracocephalum moldavica L.). The reported study was carried out in 2014 in Perespa, Poland. Over the growing season, Atonik was foliar-applied at a dose of 0.3 L/ha (0.1%) and 0.6 L/ha (0.2%) by single and double spraying of plants. Chlorophyll content and nitrogen status (N) were estimated by a Chlorophyll Meter SPAD-502 Plus. The foliar application of Atonik was found to improve the efficiency of the photosynthetic apparatus and chlorophyll content in the leaves of Dracocephalum moldavica plants, but the results were dependent on biostimulant concentration and number of its applications, and on the date of measurement. To conclude, Atonik is an environmental-friendly preparation which has a positive impact on the metabolic processes of plants.

Water-Fertilizer Coupling Effects and Efficient Utilization under Peanut-Millet Interplanting Conditions

2013 ◽  
Vol 742 ◽  
pp. 272-277
Author(s):  
Liang Shan Feng ◽  
Zhan Xiang Sun ◽  
Jia Ming Zheng
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Coupling Effect ◽  
Field Capacity ◽  
Nitrogen And Phosphorus ◽  
Application Rates ◽  
Optimal Value ◽  
Factor Interactions ◽  
Nitrogen Phosphorus

In this study, the results showed that water is the most important factor to affect crop yields and optimum soil moisture is lower under the conditions of peanut-and-millet interplanting. Thus, peanut-and-millet interplanting is generally able to fit most of the semi-arid region. In the interaction of various factors, the coupling effect of water and phosphorus was stronger than the coupling effect of fertilizers, following by the coupling effect of water and nitrogen. Among peanuts factors of water, nitrogen, and multi-factorial interaction of water, nitrogen, and phosphorus, water and nitrogen showed a negative effect, whereas the two-factor interactions had a positive effect. There were some differences between peanut and millet in the need for water and fertilizer, in which peanut required more nitrogen and millet needed slightly higher soil moisture and phosphorus. When other factors were in rich level, both of the optimal value for single factors of water, nitrogen, and phosphorus and the optimal value for two-factor interactions of water-nitrogen, water-phosphorus, and nitrogen-phosphorus, were higher than the optimal value for the interaction of water, nitrogen, and phosphorus. The tiny demand difference on moisture in peanut-millet interplanting could be compromised by configuring a reasonable interplanting population structure and the corresponding demand difference on fertilizer could be resolved by uneven crop planting strips. Under the condition of water-nitrogen-phosphorus interaction, the soil moisture content optimal for peanut accounted for 57.3% of the field capacity, and the related appropriate application rates of nitrogen and phosphorus were 0.98 g/pot (81.18 kg/hm2) and 0.39g/pot (32.18 kg/hm2), respectively. Likewise, the soil moisture content optimal for millet was 59.1% of the field capacity, and the counterpart appropriate application rates of nitrogen and phosphorus were 0.57 g/pot (47.03 kg/hm2) and 0.45g / pot (37.13 kg/hm2), respectively.

scholarly journals Growth and physiological response of two biomass sorghum (Sorghum bicolor (L.) Moench) genotypes bred for different environments, to contrasting levels of soil moisture

2015 ◽  
Vol 10 (4) ◽  
pp. 208 ◽  
Author(s):  
Lorenzo Barbanti ◽  
Ahmad Sher ◽  
Giuseppe Di Girolamo ◽  
Elio Cirillo ◽  
Muhammad Ansar
Keyword(s):  
Soil Moisture ◽  
Stomatal Conductance ◽  
Water Potential ◽  
Water Content ◽  
Aboveground Biomass ◽  
Relative Water Content ◽  
Physiological Response ◽  
Field Capacity ◽  
Biomass Sorghum ◽  
Relative Water

A better understanding of plant mechanisms in response to drought is a strong premise to achieving high yields while saving unnecessary water. This is especially true in the case of biomass crops for non-food uses (energy, fibre and forage), grown with limited water supply. In this frame, we investigated growth and physiological response of two genotypes of biomass sorghum (<em>Sorghum bicolor</em> (L.) Moench) to contrasting levels of soil moisture in a pot experiment carried out in a greenhouse. Two water regimes (high and low water, corresponding to 70% and 30% field capacity) were applied to JS-2002 and Trudan-8 sorghum genotypes, respectively bred for dry sub-tropical and mild temperate conditions. Two harvests were carried out at 73 and 105 days after seeding. Physiological traits (transpiration, photosynthesis and stomatal conductance) were assessed in four dates during growth. Leaf water potential, its components and relative water content were determined at the two harvests. Low watering curbed plant height and aboveground biomass to a similar extent (ca. 􀀀70%) in both genotypes. JS-2002 exhibited a higher proportion of belowground to aboveground biomass, <em>i.e</em>., a morphology better suited to withstand drought. Despite this, JS-2002 was more affected by low water in terms of physiology: during the growing season, the average ratio in transpiration, photosynthesis and stomatal conductance between droughty and well watered plants was, respectively, 0.82, 0.80 and 0.79 in JS-2002; 1.05, 1.08 and 1.03 in Trudan-8. Hence Trudan-8 evidenced a ca. 20% advantage in the three traits. In addition, Trudan-8 could better exploit abundant moisture (70% field capacity), increasing aboveground biomass and water use efficiency. In both genotypes, drought led to very low levels of leaf water potential and relative water content, still supporting photosynthesis. Hence, both morphological and physiological characteristics of sorghum were involved in plant adaptation to drought, in accordance with previous results. Conversely, the common assumption that genotypes best performing under wet conditions are less suited to face drought was contradicted by the results of the two genotypes in our experiment. This discloses a potential to be further exploited in programmes of biomass utilization for various end uses, although further evidence at greenhouse and field level is needed to corroborate this finding.

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