scholarly journals Differential Flag Leaf and Ear Photosynthetic Performance Under Elevated (CO2) Conditions During Grain Filling Period in Durum Wheat

2020 ◽  
Vol 11 ◽  
Author(s):  
Angie L. Gámez ◽  
Rubén Vicente ◽  
Rut Sanchez-Bragado ◽  
Iván Jauregui ◽  
Rosa Morcuende ◽  
...  
Keyword(s):  
Triticum Turgidum ◽  
Tricarboxylic Acid Cycle ◽  
Flag Leaf ◽  
Grain Filling ◽  
Good Evidence ◽  
Sugar Accumulation ◽  
Flag Leaves ◽  
Gross Photosynthesis ◽  
Respiration Rates ◽  
The Impact

Elevated concentrations of CO2 (CO2) in plants with C3 photosynthesis metabolism, such as wheat, stimulate photosynthetic rates. However, photosynthesis tends to decrease as a function of exposure to high (CO2) due to down-regulation of the photosynthetic machinery, and this phenomenon is defined as photosynthetic acclimation. Considerable efforts are currently done to determine the effect of photosynthetic tissues, such us spike, in grain filling. There is good evidence that the contribution of ears to grain filling may be important not only under good agronomic conditions but also under high (CO2). The main objective of this study was to compare photoassimilate production and energy metabolism between flag leaves and glumes as part of ears of wheat (Triticum turgidum L. subsp. durum cv. Amilcar) plants exposed to ambient [a(CO2)] and elevated [e(CO2)] (CO2) (400 and 700 μmol mol–1, respectively). Elevated CO2 had a differential effect on the responses of flag leaves and ears. The ears showed higher gross photosynthesis and respiration rates compared to the flag leaves. The higher ear carbohydrate content and respiration rates contribute to increase the grain dry mass. Our results support the concept that acclimation of photosynthesis to e(CO2) is driven by sugar accumulation, reduction in N concentrations and repression of genes related to photosynthesis, glycolysis and the tricarboxylic acid cycle, and that these were more marked in glumes than leaves. Further, important differences are described on responsiveness of flag leaves and ears to e(CO2) on genes linked with carbon and nitrogen metabolism. These findings provide information about the impact of e(CO2) on ear development during the grain filling stage and are significant for understanding the effects of increasing (CO2) on crop yield.

Awnedness affects grain yield and kernel weight in near-isogenic lines of durum wheat

2002 ◽  
Vol 53 (12) ◽  
pp. 1285 ◽  
Author(s):  
Rosella Motzo ◽  
Francesco Giunta
Keyword(s):  
Grain Yield ◽  
Durum Wheat ◽  
Photosynthetic Capacity ◽  
Triticum Turgidum ◽  
Flag Leaf ◽  
Canopy Temperature ◽  
Leaf Size ◽  
Grain Filling ◽  
Kernel Weight ◽  
Severe Drought

The importance of awns in durum wheat (Triticum turgidum L. var. durum) has to be evaluated whenever an increase in grain yield is expected due to a greater photosynthetic capacity of the awned ear. Awned and awnless isolines of durum wheat were compared in a 3-year field trial in Sardinia (Italy). Ear and flag-leaf size, radiation interception, canopy temperature, yield, and yield components were measured.Awns increased the ear surface area from 36 to 59%, depending on their length, which ranged from 5.5 to 13.8 cm. This resulted in an average 4% more radiation intercepted by the awned ears. Canopy temperature was 0.9�C lower, on average, in the awned isolines, and was negatively correlated with kernel weight (r = –0.85**, n = 10), although consistent and marked effects of awns on canopy temperature were only observed in the long-awned lines. Awns positively affected grain yield, with an average increase of 10 and 16%, respectively, in the 2 years in which they affected kernel weight. The irrelevant effect of awns on yield in the year characterised by a severe drought was a consequence of their early desiccation.The effects of awns on grain yield and kernel weight strongly depend on the genetic background, on awn length and functionality, and on the environmental conditions during grain filling.

COMPARATIVE DATA ON THE RATE OF PHOTOSYNTHESIS, RESPIRATION, AND TRANSPIRATION OF DIFFERENT ORGANS IN AWNED AND AWNLESS ISOGENIC LINES OF WHEAT

1972 ◽  
Vol 52 (6) ◽  
pp. 965-971 ◽  
Author(s):  
I. D. TEARE ◽  
J. W. SIJ ◽  
R. P. WALDREN ◽  
S. M. GOLTZ
Keyword(s):  
Flag Leaf ◽  
Wheat Yield ◽  
Net Photosynthesis ◽  
Triticum Aestivum L ◽  
Isogenic Line ◽  
Photosynthetic Rates ◽  
Flag Leaves ◽  
Isogenic Lines ◽  
Respiration Rates ◽  
The Difference

Net photosynthesis, respiration, and transpiration were determined on heads and flag leaves of two isogenic lines of wheat (Triticum aestivum L. em Thell) by measuring the difference in CO2 and water-vapor concentrations between the incoming and outgoing air streams of an open cuvette system. Net photosynthetic rates (mg CO2 dm−2 hr−1) of the awnless, awned, and awned-clipped heads were not significantly different, but the amount of photosynthesis (mg CO2 hr−1) per head was greater for the awned than for the awnless isogenic line. Net photosynthetic rates of the heads were 20–26% of the net photosynthetic rates of the flag leaves. Respiration rates were nearly two times greater for the awnless and awn-clipped heads than for the awned head. Respiration rates of the heads were 1.7 and 3.0 times greater than the respiration rates of the flag leaves of the awned and awnless isogenics, respectively. Transpiration per head was 34 and 43% of the transpiration per flag leaf for awnless and awned isogenics, respectively. Comparing P/T ratios showed that the awnless isogenic head had a 20% greater water-use efficiency than the awned. This study not only confirmed the work of others, by associating awnedness with increased wheat yield, but also showed how the chlorophyll-containing area of the head is related to photosynthesis, respiration, and transpiration.

Elevated CO2 accelerates flag leaf senescence in wheat due to ear photosynthesis which causes greater ear nitrogen sink capacity and ear carbon sink limitation

2009 ◽  
Vol 36 (4) ◽  
pp. 291 ◽  
Author(s):  
Chunwu Zhu ◽  
Jianguo Zhu ◽  
Qing Zeng ◽  
Gang Liu ◽  
Zubing Xie ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Leaf Senescence ◽  
Carbon Sink ◽  
Flag Leaf ◽  
Net Photosynthesis ◽  
Grain Filling ◽  
Flag Leaves ◽  
Sink Capacity ◽  
Sink Limitation ◽  
Grain Nitrogen

It was anticipated that wheat net photosynthesis would rise under elevated CO2, and that this would alter the progress of senescence due to the unbalance of carbohydrates and nitrogen. Our study showed that ear carbon sink was limited, and sugar was accumulated, hexokinase activities and levels of phosphorylated sugar were increased within the flag leaves, grain nitrogen sink capacity was enhanced, and flag leaf senescence was accelerated under elevated CO2. However, if the ear of the main stem was covered, these responses to elevated CO2 were absent, and the senescence of flag leaf was not accelerated by elevated CO2. Thus, it appeared that elevated CO2 accelerated the rate of flag leaf senescence, depending on ear photosynthesis. The ears have far higher enhancement of net photosynthesis than flag leaves, and the role of the flag leaf relative to the ear was declined in supplying C assimilation to grain under elevated CO2. This indicates that as CO2 rises, the grain sink needs the N more than C assimilate from flag leaf, so the declining rates of N% and soluble proteins concentration were markedly accelerated under elevated CO2 conditions. This suggests that, the large increase in ear net photosynthesis accelerated grain filling, accelerated remobilising N within flag leaf as the result of the greater grain nitrogen sink capacity. In addition, as the result of grain carbon sink limitation, it limited the export of flag leaf sucrose and enhanced sugar cycling, which was the signal to accelerate leaf senescence. Hence, elevated CO2 subsequently accelerates senescence of flag leaf.

POTENTIAL NET PHOTOSYNTHESIS IN FLAG LEAVES OF SEVERELY DROUGHT-STRESSED WHEAT CULTIVARS AND ITS RELATIONSHIP TO GRAIN YIELD

1974 ◽  
Vol 54 (4) ◽  
pp. 811-815 ◽  
Author(s):  
R. KAUL
Keyword(s):  
Desiccation Tolerance ◽  
Flag Leaf ◽  
Assimilation Efficiency ◽  
Relative Yield ◽  
Net Photosynthesis ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
Wheat Cultivars ◽  
Water Deficits ◽  
Flag Leaves

Six wheat cultivars grown in the field in 1973 showed continuously increasing water deficits which attained severe levels by the end of the season. The relative yield performance of five Triticum aestivum L. cultivars was predictable from the integrated net photosynthetic potential of their flag leaves. Grain productivity of a T. durum L. cultivar, Pelissier, was uniformly underestimated, likely because of poor desiccation tolerance of its flag leaf. It is suggested that Pelissier depended on the longevity of its heavily awned spike for additional grain filling. Results show that photosynthetic desiccation tolerance in severely stressed flag leaves of Pitic 62 ranks above that of Manitou, Cypress, and particularly Selkirk and Pelissier. Glenlea was comparable to Manitou and Cypress in flag leaf assimilation efficiency when subjected to early drought hardening, but exhibited less efficiency when subjected to water deficits late in development.

scholarly journals Unique Transcriptome And Gene Expression Analysis of Flag Leaves of A Super-Hybrid Rice WFYT025

2021 ◽  
Author(s):  
Qin Cheng ◽  
Shiying Huang ◽  
Peng Wang ◽  
Shilei Liu ◽  
Guangliang Wu ◽  
...  
Keyword(s):  
Hybrid Rice ◽  
Flag Leaf ◽  
Grain Filling ◽  
Additive Effect ◽  
Dominant Effect ◽  
Partial Dominance ◽  
Flag Leaves ◽  
Super Hybrid Rice ◽  
Highly Expressed Genes ◽  
Two Stages

Abstract Background: The health and physiology of flag leaves are closely related to rice yield, and flag leaves play an important role in providing photosynthetic products during grain filling, many breeding studies have tried to improve the performance of flag leaves. However, there are few studies on the heterosis of rice flag leaves up to now. Results: Thus, the present research is focused on the flag leaves heterosis of a widely used late-cropping indica super hybrid rice combination WFYT025 in China using a high-throughput next-generation RNA-seq strategy under different environment with two stages, trying to find some genes related to photosynthesis, transpiration, and development of seeds. Mid-parent heterosis (MPH) and higher parent heterosis (HPH) were estimated for the heterosis of flag leaf. Under the environment of middle rice, the number of genes up-regulated in CHT025, WFB and WFYT025 were 892,1,273 and 819, down-regulated in CHT025, WFB and WFYT025 were 616,1934 and 2196, respectively. Among the SDGhps on the first day after flowering, 10.9% had a dominant effect, 41.81% had a partial dominant effect, 22.07% had an additive effect and the remaining 25.22% had an over-dominant effect. Meanwhile, on the tenth day after flowering, there were 491 genes, accounting for 27.16%, showed over-dominance; 222 genes, accounting for 12.28%, showed dominance; 760 genes, accounting for 42.04%, showed partial dominance; and 335 genes, accounting for 18.52%, showed additive effect. Conclusion: The co-expressed gene sets via weighted gene co-expression network analysis (WGCNA) were identified, and total of 5,000 highly expressed genes were divided into 24 co-expression groups. In the two stages, we found 9 identical transcription factors. Except for 5 reported TFs, the other 4 TFs may play an important role in grain number and photosynthesis heterosis.

Evaluation of Triticum durum–Aegilops tauschii derived primary synthetics as potential sources of heat stress tolerance for wheat improvement

2021 ◽  
Vol 19 (1) ◽  
pp. 74-89
Author(s):  
Amandeep Kaur ◽  
Parveen Chhuneja ◽  
Puja Srivastava ◽  
Kuldeep Singh ◽  
Satinder Kaur
Keyword(s):  
Heat Stress ◽  
Stress Tolerance ◽  
Hexaploid Wheat ◽  
Aegilops Tauschii ◽  
Grain Filling ◽  
World Population ◽  
Potential Candidate ◽  
Terminal Heat Stress ◽  
Heat Stress Tolerance ◽  
The Impact

AbstractAddressing the impact of heat stress during flowering and grain filling is critical to sustaining wheat productivity to meet a steadily increasing demand from a rapidly growing world population. Crop wild progenitor species of wheat possess a wealth of genetic diversity for several biotic and abiotic stresses, and morphological traits and can serve as valuable donors. The transfer of useful variation from the diploid progenitor, Aegilops tauschii, to hexaploid wheat can be done through the generation of synthetic hexaploid wheat (SHW). The present study targeted the identification of potential primary SHWs to introduce new genetic variability for heat stress tolerance. Selected SHWs were screened for different yield-associated traits along with three advanced breeding lines and durum parents as checks for assessing terminal heat stress tolerance under timely and late sown conditions for two consecutive seasons. Heat tolerance index based on the number of productive tillers and thousand grain weight indicated that three synthetics, syn9809 (64.32, 78.80), syn14128 (50.30, 78.28) and syn14135 (58.16, 76.03), were able to endure terminal heat stress better than other SHWs as well as checks. One of these synthetics, syn14128, recorded a minimum reduction in thousand kernel weight (21%), chlorophyll content (2.56%), grain width (1.07%) despite minimum grain-filling duration (36.15 d) and has been selected as a potential candidate for introducing the terminal heat stress tolerance in wheat breeding programmes. Breeding efforts using these candidate donors will help develop lines with a higher potential to express the desired heat stress-tolerant phenotype under field conditions.

scholarly journals Growth and physiological performance responses to drought stress under non-flooded rice cultivation with straw mulching

2010 ◽  
Vol 56 (No. 2) ◽  
pp. 51-59 ◽  
Author(s):  
J. Qin ◽  
X. Wang ◽  
F. Hu ◽  
H. Li
Keyword(s):  
Flag Leaf ◽  
Early Period ◽  
Grain Filling ◽  
Antioxidant Enzyme Activity ◽  
Straw Mulching ◽  
Flooded Rice ◽  
Significant Difference ◽  
Rice Yields ◽  
Change Tendency ◽  
Soil Moisture Status

A field experiment was performed to investigate the growth performance and the growth stage-dependent changes in activities of antioxidative enzymes and concentration of malondialdehyde (MDA) in leaves of rice subjected to treatment with (NF-M) or without straw mulching (NF-WM) under non-flooded conditions compared with continuously flooded treatment (CF). Compared with the NF-WM treatment, mulch application significantly increased the flag leaf area per plant before heading, tillers number and plant height at the early period of tillering stage. There was no significant difference between the yield of the NF-WM and CF treatment. However, the yield of NF-WM treatment was significantly lower than CF and NF-M treatments. Significantly higher activities of peroxidase (POD) and catalase (CAT) but lower concentration of superoxide dismutase (SOD) and malondialdehyde (MDA) were observed in straw mulching treatment than in treatment without mulching at elongation, heading and grain filling stages. The change tendency of antioxidant enzyme activity and MDA level was in line both with soil moisture status and rice yields of different treatments.

scholarly journals The Effect of Nitrogen Fertilization and Fusarium culmorum Inoculation on the Biomarkers of Oxidative Stress in Wheat Flag Leaves

Poljoprivreda ◽  
2021 ◽  
Vol 27 (2) ◽  
pp. 15-24
Author(s):  
Magdalena Matić ◽  
◽  
Rosemary Vuković ◽  
Karolina Vrandečić ◽  
Ivna Štolfa Čamagajevac ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Lipid Peroxidation ◽  
Antioxidant Enzymes ◽  
Biotic Stress ◽  
Flag Leaf ◽  
Fusarium Culmorum ◽  
Antioxidant Response ◽  
The Impact ◽  
Biomarkers Of Oxidative Stress

During cultivation, wheat is exposed to several abiotic and/or biotic stress conditions that may adversely impact the wheat yield and quality. The impact of abiotic stress caused by nitrogen deficiency and biotic stress caused by phytopathogenic fungus Fusarium culmorum on biomarkers of oxidative stress in the flag leaf of nine winter wheat varieties (Ficko, U-1, Galloper, BC Mandica, BC Opsesija, Ingenio, Isengrain, Felix, and Bezostaya-1) was analyzed in this study. Hydrogen peroxide concentration and lipid peroxidation level were measured as indicators of oxidative stress, while the antioxidant response was determined by measuring the concentration of phenolic compounds and activities of antioxidant enzymes. Wheat variety and nitrogen treatment had a significant effect on all examined biomarkers of oxidative stress in the flag leaf, while the impact of Fusarium treatment was less pronounced. The most significant impact on the measured stress biomarkers had a low nitrogen level, which mainly increased hydrogen peroxide concentration and lipid peroxidation level and decreased activities of antioxidant enzymes in most varieties. The obtained results were discussed and compared with the previous study in which biochemical analyzes were performed on the wheat spike. There was no significant strong correlation between flag leaf and spike response in the measured parameters, which, in addition to the variety-specific response, also indicates a tissue-specific antioxidant response.

scholarly journals Effect of Heat Stress on Inter-relationship of Physiological and Biochemical Traits with Grain Yield in Wheat (Triticum aestivum L.)

2020 ◽  
pp. 19-29
Author(s):  
Amrita Kumari ◽  
R. D. Ranjan ◽  
Chandan Roy ◽  
Awadesh Kumar Pal ◽  
S. Kumar
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Flag Leaf ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
Seedling Stage ◽  
Biochemical Traits ◽  
Highly Correlated ◽  
Complex Phenomena ◽  
Physiological And Biochemical

Heat stress, particularly the stress appears at the time of flowering to grain filling stages causing severe yield loss in wheat. Heat tolerance is complex phenomena that include adjustment in morphological, physiological and biochemical traits of the crop. Present investigation was carried out to understand the effect of terminal heat stress on different traits of wheat. The experiment was conducted in three dates of sowing as timely sown, late sown and very late sown to expose the crop to heat stress at later stages of the crop growth. Significant genetic variations for all the traits evaluated under three conditions indicated the presence of variability for the traits. Trait association analysis revealed that flag leaf chlorophyll content and MSI at seedling stage; MDA at reproductive stage had direct relationship with grain yield. While under very late sown condition MDA and RWC at seedling stages were found to be highly correlated with grain yield. It indicates that MDA, RWC at seedling stage and days to booting, days to milking plays important role in very late sown condition that can be used as selection criteria in breeding programme.

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