scholarly journals Does a Large Ear Type Wheat Variety Benefit More From Elevated CO2 Than That From Small Multiple Ear-Type in the Quantum Efficiency of PSII Photochemistry?

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuting Li ◽  
Xin Li ◽  
Yujie Li ◽  
Shu Zhuang ◽  
Yongxiang Feng ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Quantum Efficiency ◽  
Carbon Sink ◽  
Flag Leaf ◽  
Sink Strength ◽  
Flag Leaves ◽  
Psii Photochemistry ◽  
Sink Size ◽  
Quantum Efficiency Of Psii

Recently, several reports have suggested that the growth and grain yield of wheat are significantly influenced by high atmospheric carbon dioxide concentration (CO2) because of it photosynthesis enhancing effects. Moreover, it has been proposed that plants with large carbon sink size will benefit more from CO2 enrichment than those with small carbon sink size. However, this hypothesis is yet to be test in winter wheat plant. Therefore, the aim of this study was to examine the effect of elevated CO2 (eCO2) conditions on the quantum efficiency of photosystem II (PSII) photochemistry in large ear-type (cv. Shanhan 8675; greater ear C sink strength) and small multiple ear-type (cv. Early premium; greater vegetative C source strength) winter wheat varieties. The experiment was conducted in a free air CO2 enrichment (FACE) facility, and three de-excitation pathways of the primary reaction of PSII of flag leaf at the anthesis stage were evaluated under two CO2 concentrations (ambient [CO2], ∼415 μmol⋅mol–1, elevated [CO2], ∼550 μmol⋅mol–1) using a non-destructive technique of modulated chlorophyll fluorescence. Additionally, the grain yield of the two varieties was determined at maturity. Although elevated CO2 increased the quantum efficiency of PSII photochemistry (ΦPSII) of Shanhan 8675 (SH8675) flag leaves at the anthesis stage, the grain number per ear and 1,000-kernel weight were not significantly affected. In contrast, the ΦPSII of early premium (ZYM) flag leaves was significantly lower than that of SH8675 flag leaves at the anthesis stage, which was caused by an increase in the regulatory non-photochemical energy dissipation quantum (ΦNPQ) of PSII, suggesting that light energy absorbed by PSII in ZYM flag leaf was largely dissipated as thermal energy. The findings of our study showed that although SH8675 flag leaves exhibited higher C sink strength and quantum efficiency of PSII photochemistry at the anthesis stage, these factors alone do not ensure improved grain yield under eCO2 conditions.

An increase in water deficit has no impact on the photosynthetic capacity of field-grown Mediterranean plants

2002 ◽  
Vol 29 (5) ◽  
pp. 621 ◽  
Author(s):  
Salvador Nogués ◽  
Leonor Alegre
Keyword(s):  
Water Deficit ◽  
Quantum Efficiency ◽  
Photosynthetic Capacity ◽  
Photosynthetic Parameters ◽  
Water Regimes ◽  
Relative Quantum ◽  
Mediterranean Plants ◽  
Psii Photochemistry ◽  
The Impact ◽  
Quantum Efficiency Of Psii

In the Mediterranean, annual mean precipitation has continuously decreased over the last three years (by ca 36% in Barcelona), and the decrease has been dramatic during the summer (by ca 78 and 64% during July and August, respectively). The impact of increased drought on the photosynthetic capacity of Mediterranean vegetation is currently unknown. In this study, two native Mediterranean plants [rosemary (Rosmarinus officinalis L.) and lavender (Lavandula stoechas L.)] were grown outdoors and subjected to two water regimes (50 mm month–1 during the summer, or no supplementary water at all). Rosemary and lavender plants watered with 50 mm month–1 during the summer had higher relative leaf water content and water potential than non-watered plants. Changes in water status were accompanied by large decreases in parameters of gas exchange [i.e. the light-saturated rate of CO2 assimilation, the maximum velocity of ribulose-1,5-bisphosphate (RuBP) carboxylation by Rubisco and the capacity for RuBP] and of modulated chlorophyll fluorescence (i.e. the relative quantum efficiency of PSII photochemistry and the efficiency of energy capture by open PSII reaction centres) during the summer, but no differences were found in any photosynthetic parameters for leaves subjected to the two water regimes. The drought-induced decreases in the relative quantum efficiency of PSII photochemistry in rosemary and lavender plants were attributable to ‘downregulation’ of electron transport. Photodamage to PSII in the field appeared to be a later effect of drought in these plants. Photorespiration was not a major mechanism protecting the photosynthetic apparatus of these plants from photodamage in the field. After the autumn rainfall, photosynthetic capacity fully recovered. We conclude that rosemary and lavender are well adapted to drought, and that an increase in water deficit is unlikely to have a significant impact on the photosynthetic capacity of leaves.

YIELD PERFORMANCE, CARBON ASSIMILATION AND SPECTRAL RESPONSE OF TRITICALE TO WATER STRESS

2016 ◽  
Vol 53 (1) ◽  
pp. 100-117 ◽  
Author(s):  
LAWRENCE MUNJONJI ◽  
KINGSLEY K. AYISI ◽  
BRAM VANDEWALLE ◽  
INOS DHAU ◽  
PASCAL BOECKX ◽  
...  
Keyword(s):  
Water Stress ◽  
Grain Yield ◽  
Carbon Content ◽  
Spectral Reflectance ◽  
Flag Leaf ◽  
Moisture Level ◽  
Yield Performance ◽  
Flag Leaves ◽  
Water Index ◽  
Spring Triticale

SUMMARYWater stress is arguably the most limiting factor affecting cereal productivity in the world and its effects are likely to increase due to climate change. It is therefore imperative to have a wide-ranging understanding of water stress effects on crop physiological processes so as to better manage, improve and adapt crops to future climates. A field study was carried out to investigate the influence of four moisture levels on the following: (1) flag leaf CO2 assimilation and flag leaf carbon content; (2) the utility of flag leaf spectral reflectance to monitor leaf water status and as an indicator of biomass and grain yield; and (3) biomass and grain yield performance of four spring triticale genotypes in a dry winter environment (steppe, arid climate). The experiment was carried out in a factorial arrangement of four moisture levels and four spring type triticale genotypes). Soil moisture level significantly influenced biomass accumulation, grain yield, CO2 assimilation, flag leaf carbon content and spectral reflectance. Grain yield levels ranged from 0.8 to 3.5 t ha−1 in 2013 and 1.8 to 4.9 t ha−1 in 2014. CO2 assimilation was significantly higher under well-watered (WW) conditions (9.92 µmol m−2 s−1 in 2013; 11.64 µmol m−2 s−1 in 2014) and decreased gradually with moisture level to 1.82 and 4.74 µmol m−2 s−1 under severe stress (SS) in 2013 and 2014, respectively. Flag leaf carbon content was significantly higher under water limited conditions compared to WW. Normalised Difference Vegetation Index (NDVI), Normalised Difference Water Index (NDWI) and Water Index (WI) were significant and positively correlated to biomass and grain yield. WI was particularly strongly correlated to biomass (0.72***) and grain yield (0.55***). However, no clear varietal effects were detected. This study revealed that carbon tends to accumulate in flag leaves under water stress and that flag leaf carbon content is influenced more by the export capacity of the flag leaves than on CO2 assimilation rate. WI was found to be superior index in monitoring water stress in triticale compared to NDVI and NDWI. Above all, spring triticale proved to be adaptable to steppe (dry) climate of Limpopo and that livestock farmers in the province can successfully grow triticale for silage under MS conditions.

scholarly journals The Stimulatory Effects of Nanochitin Whisker on Carbon and Nitrogen Metabolism and on the Enhancement of Grain Yield and Crude Protein of Winter Wheat

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1752 ◽  
Author(s):  
Yingying Cheng ◽  
Yi Wang ◽  
Yanlai Han ◽  
Dongya Li ◽  
Zhongkui Zhang ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Enzyme Activities ◽  
Crude Protein ◽  
Protein Concentration ◽  
Sucrose Phosphate Synthase ◽  
Metabolic Enzyme ◽  
Growth Stages ◽  
N Accumulation ◽  
Flag Leaves

Nanochitin whisker (NC) with a cationic nature could enhance plant photosynthesis, grain yield, and quality of wheat, but have not been systematically studied. This study was designed to investigate the stimulatory effects of NC on dry matter (DM) and nitrogen (N) accumulation and translocation, and on the metabolism of carbon (C) and N in later growth stages of winter wheat to reveal the enhancement mechanism of grain yield and crude protein concentration. Different parts of NC-treated plants from pot grown experiments were collected at the pre- and post-anthesis stages. The accumulation, translocation, and contributions of DM and N from pre-anthesis vegetation organs to grains, as well as key metabolic enzyme activities, including sucrose phosphate synthase (SPS) and phosphoenolpyruvate carboxylase (PEPC), were examined. The results showed that, at an application rate of 6 mg·kg−1 of NC in the soil, the accumulation of DM and N were significantly enhanced by 16.2% and 38.8% in pre-anthesis, and by 15.4% and 30.0% in post-anthesis, respectively. Translocation of N and DM in the post-anthesis periods were enhanced by 38.4% and 50.9%, respectively. NC could also stimulate enzyme activities, and increased 39.8% and 57.1% in flag leaves, and by 36.0% and 58.8% in spikes, respectively, at anthesis. SPS and PEPC increased by 28.2% and 45.1% in flag leaves, and by 42.2% and 56.5% in spikes, respectively, at 15 days after anthesis. The results indicated that the NC promoted N metabolism more than C metabolism, and resulted in the enhancement of grain yield by 27.56% and of crude protein concentration in grain by 13.26%, respectively.

GENOTYPIC VARIATION IN SOME PHYSIOLOGICAL TRAITS IN WINTER WHEAT GROWN IN THE HUMID CONTINENTAL CLIMATE OF ONTARIO

1984 ◽  
Vol 64 (1) ◽  
pp. 113-118 ◽  
Author(s):  
I. AGUILAR-M. ◽  
L. A. HUNT
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Grain Yield ◽  
Morphological Traits ◽  
Flag Leaf ◽  
Genotypic Variation ◽  
Triticum Aestivum L ◽  
Eastern Canada ◽  
Area Index ◽  
Diffusive Resistance

Several experiments were conducted with winter wheat (Triticum aestivum L. em. Thell.) during 1978 and 1979 to characterize genotypic variation in some physiological and morphological traits, and to evaluate the magnitude of the relationships between grain yield and the various traits studied. Straw weights of cultivars grown in Eastern Canada were similar to, and harvest indices generally lower than, those reported for high yielding varieties from other countries. Highest grain weights were also lower than the upper values recorded for some cultivars in the U.K. and Mexico, and were little affected by spikelet removal in most cases. All experiments were consistent in showing highly significant correlations between grain yield and grains per square metre, straw weight, harvest index, spikes per square metre, and flag leaf area index, and significant correlations between grain yield and grain weight. Diffusive resistance of the adaxial surface of the flag leaves differed between genotypes, but correlations between diffusive resistance and yield were low and nonsignificant in all cases, with the exception of the preanthesis period in one experiment.Key words: Wheat (winter), Triticum aestivum L. em. Thell., yield, physiological-morphological traits.

Nitrogen-Reducing and Suitable Soil Moisture Enhance Photosynthetic Poten-tial of Flag Leaf and Grain Yield in Winter Wheat

2016 ◽  
Vol 42 (11) ◽  
pp. 1677 ◽  
Author(s):  
Su-Mei ZHOU ◽  
Ke-Ke ZHANG ◽  
Man ZHANG ◽  
Lei LI ◽  
Chun-Li ZHANG ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Winter Wheat ◽  
Grain Yield ◽  
Flag Leaf

Changes in the angle and curvature of the uppermost leaves of winter wheat

1978 ◽  
Vol 90 (2) ◽  
pp. 319-323 ◽  
Author(s):  
J. P. Ledent
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Flag Leaf ◽  
Rate Of Change ◽  
Leaf Angle ◽  
Leaf Movement ◽  
Downward Movement ◽  
Angle Change

SummaryEach of the three uppermost leaves of wheat canopies studied in 1975 and 1976 showed a downward movement after its emergence. The variations with time of leaf angle were greatest in the flag leaf. Genotypes differed markedly in the rate of change with age in flag-leaf angle. Leaf curvature did not vary with age. There were differences between years in the rate of leaf movement, but cultivars ranked roughly the same in terms of leaf angle in each year. Grain yield per hectare was not related to leaf angle change. Most of the higher-yielding genotypes included in the study had straight leaves, the correlation between curvature and yield being —0·30 in 1975 and —0·60 in 1976.

Modelling photosynthesis in flag leaves of winter wheat (Triticum aestivum) considering the variation in photosynthesis parameters during development

2015 ◽  
Vol 42 (11) ◽  
pp. 1036 ◽  
Author(s):  
Jingsong Sun ◽  
Jindong Sun ◽  
Zhaozhong Feng
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Leaf Development ◽  
Flag Leaf ◽  
Seasonal Fluctuation ◽  
Triticum Aestivum L ◽  
Growth Conditions ◽  
Seasonal Patterns ◽  
Flag Leaves ◽  
Parameter Values

The Farquhar–von Caemmerer–Berry (FvCB) model of photosynthesis has been widely used to estimate the photosynthetic C flux of plants under different growth conditions. However, the seasonal fluctuation of some photosynthesis parameters (e.g. the maximum carboxylation rate of Rubisco (Vcmax), the maximum electron transport rate (Jmax) and internal mesophyll conductance to CO2 transport (gm)) is not considered in the FvCB model. In this study, we investigated the patterns of the FvCB parameters during flag leaf development based on measured photosynthesis–intercellular CO2 curves in two cultivars of winter wheat (Triticum aestivum L.). Parameterised seasonal patterns of photosynthesis parameters in the FvCB model have subsequently been applied in order to predict the photosynthesis of flag leaves. The results indicate that the Gaussian curve characterises the dynamic patterns of Vcmax, Jmax and gm well. Compared with the model with fixed photosynthesis parameter values, updating the FvCB model by considering seasonal changes in Vcmax and Jmax during flag leaf development slightly improved predictions of photosynthesis. However, if the updated FvCB model incorporated the seasonal patterns of Vcmax and Jmax, and also of gm, predictions of photosynthesis was improved a lot, matching well with the measurements (R2 = 0.87, P < 0.0001). This suggests that the dynamics of photosynthesis parameters, particularly gm, play an important role in estimating the photosynthesis rate of winter wheat.

scholarly journals Effects of different fertilizer ratio on senescence of flag leaf in winter wheat

2020 ◽  
Vol 49 (1) ◽  
pp. 85-90
Author(s):  
Yafei Wang ◽  
Yan Shi
Keyword(s):  
Winter Wheat ◽  
Water Retention ◽  
Slow Release ◽  
Flag Leaf ◽  
High Yield ◽  
Flag Leaves ◽  
Slow Release Fertilizer ◽  
Compound Fertilizer ◽  
Mda Content ◽  
Use Efficiency

In order to increase the fertilizer use efficiency, the effects of different ratio of slow-release fertilizer, water retention agent and compound fertilizer in wheat production on senescence of flag leaf in winter wheat had been studied. The results showed that, water retaining agent 15 kg/ha with slow-release fertilizer 324 kg/ha and compound fertilizer 324 kg/ha (T2) effectively maintained the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) activity and soluble protein content in wheat flag leaves after flowering, and reduced the malondialdehyde (MDA) content which could delay the flag leaves senescence and gain high yield in wheat.

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