scholarly journals Maintaining higher leaf photosynthesis after heading stage could promote biomass accumulation in rice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sotaro Honda ◽  
Satoshi Ohkubo ◽  
Nan Su San ◽  
Anothai Nakkasame ◽  
Kazuki Tomisawa ◽  
...  
Keyword(s):  
Biomass Accumulation ◽  
Growing Season ◽  
Crop Productivity ◽  
Genomic Region ◽  
Strongly Correlated ◽  
Leaf Photosynthesis ◽  
Crop Growth Rate ◽  
Curve Smoothing ◽  
High Maximum ◽  
Leaf Photosynthetic Rate

AbstractLeaf photosynthetic rate changes across the growing season as crop plants age. Most studies of leaf photosynthesis focus on a specific growth stage, leaving the question of which pattern of photosynthetic dynamics maximizes crop productivity unanswered. Here we obtained high-frequency data of canopy leaf CO2 assimilation rate (A) of two elite rice (Oryza sativa) cultivars and 76 inbred lines across the whole growing season. The integrated A value after heading was positively associated with crop growth rate (CGR) from heading to harvest, but that before heading was not. A curve-smoothing analysis of A after heading showed that accumulated A at > 80% of its maximum (A80) was positively correlated with CGR in analyses of all lines mixed and of lines grouped by genetic background, while the maximum A and accumulated A at ≤ 80% were less strongly correlated with CGR. We also found a genomic region (~ 12.2 Mb) that may enhance both A80 and aboveground biomass at harvest. We propose that maintaining a high A after heading, rather than having high maximum A, is a potential target for enhancing rice biomass accumulation.

scholarly journals Association Between Leaf Photosynthesis and Biomass Accumulation in Rice Illustrated by A Comprehensive Gas Exchange Profile Across the Growing Season

2020 ◽  
Author(s):  
Sotaro Honda ◽  
Satoshi Ohkubo ◽  
Nan San ◽  
Anothai Nakkasame ◽  
Kazuki Tomisawa ◽  
...  
Keyword(s):  
Biomass Accumulation ◽  
Growing Season ◽  
Crop Productivity ◽  
Genomic Region ◽  
Strongly Correlated ◽  
Leaf Photosynthesis ◽  
Crop Growth Rate ◽  
Curve Smoothing ◽  
High Maximum ◽  
Leaf Photosynthetic Rate

Abstract Leaf photosynthetic rate changes across the growing season as crop plants age. Most studies of leaf photosynthesis focus on a specific growth stage, leaving the question of which pattern of photosynthetic dynamics maximizes crop productivity unanswered. Here we obtained high-frequency data of canopy leaf CO2 assimilation rate (A) of two elite rice (Oryza sativa) cultivars and 76 inbred lines across the whole growing season. The integrated A value after heading was closely associated with crop growth rate (CGR) from heading to harvest, but that before heading was not. A curve-smoothing analysis of A after heading showed that accumulated A at >80% of its maximum (A80) was closely correlated with CGR in analyses of all lines mixed and of lines grouped by genetic background, while the maximum A and accumulated A at ≤80% were less strongly correlated with CGR. We also found a genomic region that may enhance both A80 and aboveground biomass at harvest. We propose that maintaining a high A after heading, rather than having high maximum A, is a potential target for enhancing rice biomass accumulation.

Scaling leaf photosynthesis to canopy in a mixed deciduous forest. I. model description

1997 ◽  
Vol 62 ◽  
Author(s):  
R. Samson ◽  
S. Follens ◽  
R. Lemeur
Keyword(s):  
Temperature Dependence ◽  
Quercus Robur ◽  
Deciduous Forest ◽  
Growing Season ◽  
Model Description ◽  
Canopy Photosynthesis ◽  
Leaf Photosynthesis ◽  
Layer Model ◽  
Mixed Deciduous Forest ◽  
Leaf Level

A  multi-layer model (FORUG) was developed, to simulate the canopy  photosynthesis of a mixed deciduous forest during the growing season.  Measured photosynthesis parameters, for beech (Fagus  sylvatica), oak (Quercus  robur) and ash (Fraxinus  excelsior), were used as input to the model. This  information at the leaf level is then scaled up to the level of the canopy,  taking into account the radiation profiles (diffuse and direct PAR) in the  canopy, the vertical LAI distribution, the evolution of the LAI and the  photosynthesis parameters during the growing season, and the temperature  dependence of the latter parameters.

scholarly journals Dynamics of Specific cfDNA Fragments in the Plasma of Full Marathon Participants

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 676
Author(s):  
Takehito Sugasawa ◽  
Shin-ichiro Fujita ◽  
Tomoaki Kuji ◽  
Noriyo Ishibashi ◽  
Kenshirou Tamai ◽  
...  
Keyword(s):  
Exercise Physiology ◽  
High Sensitivity ◽  
Genomic Region ◽  
Qpcr Assay ◽  
Strongly Correlated ◽  
Healthy Humans ◽  
Blood Cell And Plasma ◽  
Next Generation Sequencing Ngs ◽  
Taqman Qpcr Assay ◽  
Taqman Qpcr

Plasma cell-free DNA (cfDNA) is frequently analyzed using liquid biopsy to investigate cancer markers. We hypothesized that this concept might be applicable in exercise physiology. Here, we aimed to identify specific cfDNA (spcfDNA) sequences in the plasma of healthy humans using next-generation sequencing (NGS) and clearly define the dynamics regarding spcfDNA-fragment levels upon extreme exercises, such as running a full marathon. NGS analysis was performed using cfDNA of pooled plasma collected from healthy participants. We confirmed that the TaqMan-qPCR assay had high sensitivity and found that the spcfDNA sequence abundance was 16,600-fold higher than that in a normal genomic region. We then used the TaqMan-qPCR assay to investigate the dynamics of spcfDNA-fragment levels upon running a full marathon. The spcfDNA fragment levels were significantly increased post-marathon. Furthermore, spcfDNA fragment levels were strongly correlated with white blood cell and plasma myoglobin concentrations. These results suggest the spcfDNA fragments identified in this study were highly sensitive as markers of extreme physical stress. The findings of this study may provide new insights into exercise physiology and genome biology in humans.

Radiation absorption, growth and yield of cereals

1978 ◽  
Vol 91 (1) ◽  
pp. 47-60 ◽  
Author(s):  
J. N. Gallagher ◽  
P. V. Biscoe
Keyword(s):  
Dry Matter ◽  
Growing Season ◽  
Growth Efficiency ◽  
Growth And Yield ◽  
Radiation Absorption ◽  
Exponential Equation ◽  
Crop Cover ◽  
Crop Growth Rate ◽  
Wide Range ◽  
Total Crop

SummaryAnalysis of measurements of absorbed radiation and leaf area indices of wheat and barley crops showed that throughout most of growth the fraction of absorbed solar radiation could be described by a simple exponential equation.For several of these crops grown under a wide range of weather and husbandry at Sutton Bonington and Rothamsted, 2-weekly values of crop growth rate (C) were closely related to radiation absorbed until ear emergence and about 3·0 g of dry matter (D.M.) were produced by each MJ of photosynthetically active radiation (PAR) absorbed. Final crop weight was closelyrelated to total PAR absorbed during growth (SA); on average about 2·2 g D.M. were produced per MJ absorbed, equivalent to a growth efficiency (Eg) of approximately 3·9%. Unfertilized and drought-stressed crops had a smaller Eg.The fraction of total crop D.M. harvested as grain (harvest index) varied more for wheat than for barley. Calculations of a maximum realizable grain yield made using the largest values of Eg and SA for the crops measured and assuming a harvestindex of 0.53 (achieved in an experimental crop) showed a grain D.M. yield of 10·3 t D.M./ha to be possible. To achieve such a yield would require full crop cover from the beginning of April until the end of July in a typical English growing season.

scholarly journals Limiting transpiration rate in high evaporative demand conditions to improve Australian wheat productivity

2021 ◽  
Author(s):  
Brian Collins ◽  
Scott Chapman ◽  
Graeme Hammer ◽  
Karine Chenu
Keyword(s):  
Transpiration Rate ◽  
Production Systems ◽  
Water Productivity ◽  
Biomass Accumulation ◽  
Climate Scenario ◽  
Grain Filling ◽  
Crop Productivity ◽  
Evaporative Demand ◽  
Lysimeter Experiment ◽  
Grain Filling Period

Abstract Limited-transpiration rate at high evaporative demand (‘LTR’ trait) has potential to improve drought adaptation, crop water productivity and food security. The quantification of the implications of LTR for water consumption, biomass accumulation and yield formation requires the use of dynamic crop modelling to simulate physiological and environmental processes and interactions in target environments. Here, a new transpiration module was developed for the Agricultural Production Systems sIMulator (APSIM NextGen) and used to simulate atmospheric and edaphic water stress on wheat crops. This module was parameterised with (i) data from a lysimeter experiment assessing genotypic variability in the LTR trait for four genotypes contrasting in transpiration efficiency, and with (ii) a more pronounced response to high evaporative demand. The potential of the LTR trait for improving crop productivity was investigated across the Australian wheatbelt over 1989-2018. The LTR trait was simulated to allow an increase in national yield by up to 2.6%, mostly due to shift in water use pattern, alleviation of water deficit during grain filling period and a higher harvest index. Greatest productivity gains were found in the northeast (4.9%, on average) where heavy soils allow the conserved water with the LTR trait to be available later at more critical stages. The effect of the LTR trait on yield was enhanced under the future climate scenario, particularly in the northeast. Limiting transpiration at high evaporative demands appears to be a promising trait for selection by breeders, especially in drought-prone environments where crops heavily rely on stored soil moisture.

POTENTIAL VEGETATIVE PRODUCTIVITY IN CANADA

1983 ◽  
Vol 63 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. TOLLENAAR
Keyword(s):  
Photosynthetic Efficiency ◽  
Theoretical Estimate ◽  
Growing Season ◽  
Crop Growth ◽  
Light Interception ◽  
Crop Species ◽  
Potential Productivity ◽  
Crop Growth Rate ◽  
Water Nutrients ◽  
Productivity Estimate

Duration of the growing season appears to be the single most important factor limiting vegetative productivity in Canada. A theoretical estimate of annual vegetative productivity in the absence of limitations due to water, nutrients or soil structure, shows that potential productivity in the 5-mo growing season of Southern Canada is in the range of 25–55 tonne/ha. Maximum productivity, however, lies considerably below the potential productivity estimate due to lower-than-expected photosynthetic efficiency during periods of high solar irradiance. Crop growth rates appear to be rather independent of variation in radiant flux density during the growing season. Consequently, a realistic estimate of maximum vegetative productivity can be obtained by multiplying number of days of full light interception by a crop canopy, by a crop growth rate of 230 kg∙h−1∙day−1 and adding the weight of the crop at the onset of full light interception by the canopy. Maximum vegetative productivity could likely be improved by extending the period of full light interception by crop canopies through the cultivation of perennial species or double-crop sequences. Alternatively, vegetative productivity could likely be improved through increased photosynthetic efficiency. Very high photosynthetic efficiencies of crops grown under field conditions have been reported occasionally in the literature, but factors underlying this high photosynthetic efficiency have not yet been identified.Key words: Vegetative production, photosynthetic efficiency, potential productivity, duration of growing season, crop species

Woody tissue photosynthesis increases radial stem growth of young poplar trees under ambient atmospheric CO2 but its contribution ceases under elevated CO2

2020 ◽  
Vol 40 (11) ◽  
pp. 1572-1582
Author(s):  
Linus De Roo ◽  
Fran Lauriks ◽  
Roberto Luis Salomón ◽  
Jacek Oleksyn ◽  
Kathy Steppe
Keyword(s):  
Co2 Concentration ◽  
Growing Season ◽  
Stem Growth ◽  
Atmospheric Co2 ◽  
Canopy Conductance ◽  
Leaf Photosynthesis ◽  
Woody Tissue ◽  
Atmospheric Co2 Concentration ◽  
Tree Survival ◽  
Woody Tissue Photosynthesis

Abstract Woody tissue photosynthesis (Pwt) contributes to the tree carbon (C) budget and generally stimulates radial stem growth under ambient atmospheric CO2 concentration (aCO2). Moreover, Pwt has potential to enhance tree survival under changing climates by delaying negative effects of drought stress on tree hydraulic functioning. However, the relevance of Pwt on tree performance under elevated atmospheric CO2 concentration (eCO2) remains unexplored. To fill this knowledge gap, 1-year-old Populus tremula L. seedlings were grown in two treatment chambers at aCO2 and eCO2 (400 and 660 ppm, respectively), and woody tissues of half of the seedlings in each treatment chamber were light-excluded to prevent Pwt. Radial stem growth, sap flow, leaf photosynthesis and stomatal and canopy conductance were measured throughout the growing season, and the concentration of non-structural carbohydrates (NSC) in stem tissues was determined at the end of the experiment. Fuelled by eCO2, an increase in stem growth of 18 and 50% was observed in control and light-excluded trees, respectively. Woody tissue photosynthesis increased radial stem growth by 39% under aCO2, while, surprisingly, no impact of Pwt on stem growth was observed under eCO2. By the end of the growing season, eCO2 and Pwt had little effect on stem growth, leaf photosynthesis acclimated to eCO2, but stomatal conductance did not, and homeostatic stem NSC pools were observed among combined treatments. Our results highlight that eCO2 potentially fulfils plant C requirements, limiting the contribution of Pwt to stem growth as atmospheric [CO2] rises, and that radial stem growth in young developing trees was C (source) limited during early phenological stages but transitioned towards sink-driven control at the end of the growing season.

The contribution of pod numbers to field pea (Pisum sativum L.) yields in a short growing-season environment

1990 ◽  
Vol 41 (5) ◽  
pp. 853 ◽  
Author(s):  
RJ French
Keyword(s):  
Seed Size ◽  
Seed Yield ◽  
Growing Season ◽  
Field Pea ◽  
Strongly Correlated ◽  
Sowing Time ◽  
Reproductive Phase ◽  
Total Seed ◽  
Main Effects ◽  
Short Growing Season

Field pea yields in three sowing-time experiments in 1985, and two experiments in 1986, were split into the following components: pods m-2, seeds pod-1 and average seed size. In both years pods m-2 was the component most strongly correlated with yield, but the others were also positively correlated with yield. Multivariate analysis of variance showed that pods m-2 contributed more than the other components to the site and sowing-time main effects in both years. Seeds pod-1 made no contribution in either year, but average seed size contributed to the site main effect in 1985 and to the sowing time and cultivar main effects in 1986. These results identify pods m-2 as the most responsive component to environmental effects on field pea yield. Pods m-2 was split into stems m-2 and pods stem-1, or into the rate of pod formation and the duration of pod formation. Variation in both stems m-2 and pods stem-1 contributed to differences in pods m-2 in the 1986 experiments. In a comparison of two Derrimut pea crops grown at Merredin in 1984 and 1985, the duration of pod formation and the rate of pod formation both varied. Variation in the rate of pod formation was due to differences in stems m-2 rather than in rates of pod formation stem-1. Pods formed early in the reproductive phase contributed much more to total seed yield than those formed later. This was due to later-formed pods containing fewer seeds and being more likely than early-formed pods to abscise before reaching maturity. The proportion of total seed yield carried on the first three reproductive nodes varied from 64.3% to 94.2%. This proportion was higher in harsher environments. It is suggested that in short growing-season environments increased pod formation rates are desirable to allow compression of the pod formation period, so that fewer pods will be formed late in the reproductive phase when the environment is most limiting.

Interaction of nutrient-loaded black spruce seedlings with neighbouring vegetation in greenhouse environments

1995 ◽  
Vol 25 (6) ◽  
pp. 1017-1023 ◽  
Author(s):  
Vikram Malik ◽  
Victor R. Timmer
Keyword(s):  
Negative Correlation ◽  
Competitive Ability ◽  
Black Spruce ◽  
Biomass Accumulation ◽  
Growing Season ◽  
Significant Negative Correlation ◽  
Biomass Growth ◽  
Naturally Occurring ◽  
Nutrient Reserves ◽  
Accumulation Slope

The interaction of newly planted, nutrient-loaded black spruce (Piceamariana (Mill.) B.S.P.) seedlings with naturally occurring vegetation was investigated for one growing season under greenhouse conditions using bioassays retrieved from a boreal mixedwood site. Nutrient-loaded seedlings were similar in height and biomass to conventionally fertilized seedlings at planting, but contained 43, 76, and 33% more tissue N, P, and K content due to higher nursery fertilization, which induced luxury consumption. Nutrient-loaded seedlings outperformed conventionally fertilized seedlings in respective height and biomass growth by 35 and 28% in herbicide-treated plots, and by 44 and 37% in untreated plots, resulting in a 27% reduction in neighbouring vegetation biomass by the end of the season. The loading treatments stimulated nutrient uptake after planting, although the depletion of preplant nutrient reserves was greater. A significant negative correlation was observed between tree and weed biomass accumulation. Slope differences indicated that loaded trees were less sensitive to neighbouring vegetation than conventionally fertilized trees. The enhanced competitive ability of loaded seedlings against naturally occurring vegetation was probably due to the translocation of more nutrients to actively growing parts from reserves built up during the nursery preconditioning phase.

Seasonal biomass accumulation and nutrient uptake of wheat, barley and oat on a Black Chernozem Soil in Saskatchewan

2006 ◽  
Vol 86 (4) ◽  
pp. 1005-1014 ◽  
Author(s):  
S. S. Malhi ◽  
A. M. Johnston ◽  
J. J. Schoenau ◽  
Z. L. Wang ◽  
C. L. Vera
Keyword(s):  
Nutrient Uptake ◽  
Uptake Rate ◽  
Accumulation Rate ◽  
Biomass Accumulation ◽  
Growing Season ◽  
Early Growth ◽  
Growth Stages ◽  
Nutrient Accumulation ◽  
Maximum Biomass ◽  
Cereal Species

Dry matter and nutrient accumulation in the growing season are the main factors in the determination of seed yield and nutrient use efficiency. Field experiments were conducted with spring wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and oat (Avena sativa L.) in 1998 and 1999 at Melfort, Saskatchewan, Canada, to determine the biomass accumulation and plant nutrient uptake at different growth stages, and their relationship with days after emergence (DAE) and growing degree days (GDD). All crops generally followed a similar pattern of biomass and nutrient accumulation in the growing season, which increased continuously with growing time, with much faster increase at early growth stages than at late growth stages. Maximum biomass accumulation rate and amount usually occurred at late boot stage (46–47 DAE or 443–460 GDD) and ripening stage (89–90 DAE or 948–1050 GDD), respectively. Maximum rate of nutrient uptake occurred at tillering to stem elongation stages (22–36 DAE or 149–318 GDD). Maximum amount of nutrient uptake generally occurred at the beginning of flowering to medium milk stages (61–75 DAE or 612–831 GDD), except for P in 1998 when it occurred at late milk to ripening stages (80–90 DAE or 922–1050 GDD). In general, the maximum nutrient uptake rate and amount, respectively, occurred earlier than maximum biomass accumulation rate and amount. For various cereal species/cultivars, maximum biomass accumulation rate was 204–232 kg ha-1 d-1, and maximum uptake rate of N, P, K and S, respectively, was 3.2–5.7, 0.30–0.60, 3.85–7.05 and 0.45–0.60 kg ha-1 d-1. The findings suggest that a sufficient supply of nutrients from soil and fertilizers at early growth stages is of great importance for optimum crop yield. Key words: Barley, biomass accumulation, cereals, growth stages, nutrient uptake, oat, wheat

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