The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Xinguang Zhu - One of the best experts on this subject based on the ideXlab platform.
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a three dimensional Canopy photosynthesis model in rice with a complete description of the Canopy Architecture leaf physiology and mechanical properties
Journal of Experimental Botany, 2019Co-Authors: Tiangen Chang, Honglong Zhao, Ning Wang, Qingfeng Song, Yi Xiao, Xinguang ZhuAbstract:In current rice breeding programs, morphological parameters such as plant height, leaf length and width, leaf angle, panicle Architecture, and tiller number during the grain filling stage are used as major selection targets. However, so far, there is no robust approach to quantitatively define the optimal combinations of parameters that can lead to increased Canopy radiation use efficiency (RUE). Here we report the development of a three-dimensional Canopy photosynthesis model (3dCAP), which effectively combines three-dimensional Canopy Architecture, Canopy vertical nitrogen distribution, a ray-tracing algorithm, and a leaf photosynthesis model. Concurrently, we developed an efficient workflow for the parameterization of 3dCAP. 3dCAP predicted daily Canopy RUE for different nitrogen treatments of a given rice cultivar under different weather conditions. Using 3dCAP, we explored the influence of three Canopy architectural parameters-tiller number, tiller angle and leaf angle-on Canopy RUE. Under different weather conditions and different nitrogen treatments, Canopy Architecture optimized by manipulating these parameters can increase daily net Canopy photosynthetic CO2 uptake by 10-52%. Generally, a smaller tiller angle was predicted for most elite rice Canopy Architectures, especially under scattered light conditions. Results further show that similar Canopy RUE can be obtained by multiple different parameter combinations; these combinations share two common features of high light absorption by leaves in the Canopy and a high level of coordination between the nitrogen concentration and the light absorbed by each leaf within the Canopy. Overall, this new model has potential to be used in rice ideotype design for improved Canopy RUE.
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optimal crop Canopy Architecture to maximise Canopy photosynthetic co2 uptake under elevated co2 a theoretical study using a mechanistic model of Canopy photosynthesis
Functional Plant Biology, 2013Co-Authors: Qingfeng Song, Guilian Zhang, Xinguang ZhuAbstract:Canopy Architecture has been a major target in crop breeding for improved yields. Whether crop Architectures in current elite crop cultivars can be modified for increased Canopy CO2 uptake rate (Ac) under elevated atmospheric CO2 concentrations (Ca) is currently unknown. To study this question, we developed a new model of Canopy photosynthesis, which includes three components: (i) a Canopy architectural model; (ii) a forward ray tracing algorithm; and (iii) a steady-state biochemical model of C3 photosynthesis. With this model, we demonstrated that the Ac estimated from ‘average’ Canopy light conditions is ~25% higher than that from light conditions at individual points in the Canopy. We also evaluated theoretically the influence of Canopy architectural on Ac under current and future Ca in rice. Simulation results suggest that to gain an optimal Ac for the examined rice cultivar, the stem height, leaf width and leaf angles can be manipulated to enhance Canopy photosynthesis. This model provides a framework for designing ideal crop Architectures to gain optimal Ac under future changing climate conditions. A close linkage between Canopy photosynthesis modelling and Canopy photosynthesis measurements is required to fully realise the potential of such modelling approaches in guiding crop improvements.
Penny Riffkin - One of the best experts on this subject based on the ideXlab platform.
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selection for erect Canopy Architecture can increase yield and biomass of spring wheat
Field Crops Research, 2019Co-Authors: R A Richards, Colin Cavanagh, Penny RiffkinAbstract:Abstract In wheat (Triticum aestivum L.) Canopy Architecture influences light penetration into the Canopy and radiation use efficiency particularly during the period between stem elongation and anthesis which is the critical time for the determination of yield. Despite large differences in Canopy Architecture among spring wheat genotypes, ranging from erectophile to planophile upper leaves, there is little prior evidence to suggest that selection for Canopy Architecture influences yield. In this study we evaluated the variation for Canopy Architecture in a 4-way MAGIC population (n=∼ 1000 lines) developed from 4 Australian commercial spring wheats and an 8-way MAGIC population (n=∼ 300 lines) developed from 3 Australian and 5 northern hemisphere commercial wheats. The 4-way population was grown at both an irrigated and a dryland site in southern New South Wales whereas the 8-way population was grown at the irrigated site. We also measured grain yield, plant height and crop development stage at the irrigated site. Using a smaller subset of lines which we grouped into either erectophile or planophile we studied how Canopy Architecture influences grain yield and associated yield traits (above-ground biomass (AGBM), harvest index, yield components, flowering time and height). The grain yield in the latter experiments varied from 5 to 6 t ha−1. Averaged over two years and two sowing dates in each year lines that were erectophile yielded 13% more than the planophile lines and most of this yield advantage was associated with a higher AGBM (11%). Erectophile lines had 24% more grains per unit area but a 9% lower grain weight. Erectophile lines flowered 2 days later than planophile lines and they were 7 cm shorter. Lodging, although rare in these studies, was more evident in the planophile lines. In both MAGIC populations the most erectophile lines yielded 24% more grain than the most planophile lines. Mapping was conducted on the 1000 lines from the 4-way MAGIC population grown at the irrigated and the dryland site. It showed that genetic control of Canopy Architecture was complex but QTL were generally repeatable at both sites. Significant QTL were identified on most chromosomes. G x E was low for Canopy Architecture as the scores were repeatable across years (r2 = 0.85). This trait opens the way to improve wheat yields via increasing crop biomass which in the past has been largely intractable in breeding programs.
Erik H Murchie - One of the best experts on this subject based on the ideXlab platform.
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exploring relationships between Canopy Architecture light distribution and photosynthesis in contrasting rice genotypes using 3d Canopy reconstruction
Frontiers in Plant Science, 2017Co-Authors: Alexandra J Burgess, Renata Retkute, Tiara Herman, Erik H MurchieAbstract:The arrangement of leaf material is critical in determining the light environment, and subsequently the photosynthetic productivity of complex crop canopies. However, links between specific Canopy architectural traits and photosynthetic productivity across a wide genetic background are poorly understood for field grown crops. The Architecture of five genetically diverse rice varieties - four parental founders of a multi-parent advanced generation intercross (MAGIC) population plus a high yielding Philippine variety (IR64) - was captured at two different growth stages using a method for digital plant reconstruction based on stereocameras. Ray tracing was employed to explore the effects of Canopy Architecture on the resulting light environment in high-resolution, whilst gas exchange measurements were combined with an empirical model of photosynthesis to calculate an estimated carbon gain and total light interception. To further test the impact of different dynamic light patterns on photosynthetic properties, an empirical model of photosynthetic acclimation was employed to predict the optimal light-saturated photosynthesis rate (Pmax) throughout Canopy depth, hypothesising that light is the sole determinant of productivity in these conditions. First we show that a plant type with steeper leaf angles allows more efficient penetration of light into lower Canopy layers and this, in turn, leads to a greater photosynthetic potential. Second the predicted optimal Pmax responds in a manner that is consistent with fractional interception and leaf area index across this germplasm. However measured Pmax, especially in lower layers, was consistently higher than the optimal Pmax indicating factors other than light determine photosynthesis profiles. Lastly, varieties with more upright Architecture exhibit higher maximum quantum yield of photosynthesis indicating a Canopy-level impact on photosynthetic efficiency.
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high resolution three dimensional structural data quantify the impact of photoinhibition on long term carbon gain in wheat canopies in the field
Plant Physiology, 2015Co-Authors: Alexandra J Burgess, Renata Retkute, Michael P Pound, J Foulkes, Simon P Preston, Oliver E Jensen, Tony P Pridmore, Erik H MurchieAbstract:Photoinhibition reduces photosynthetic productivity; however, it is difficult to quantify accurately in complex canopies partly because of a lack of high-resolution structural data on plant Canopy Architecture, which determines complex fluctuations of light in space and time. Here, we evaluate the effects of photoinhibition on long-term carbon gain (over 1 d) in three different wheat (Triticum aestivum) lines, which are architecturally diverse. We use a unique method for accurate digital three-dimensional reconstruction of canopies growing in the field. The reconstruction method captures unique architectural differences between lines, such as leaf angle, curvature, and leaf density, thus providing a sensitive method of evaluating the productivity of actual Canopy structures that previously were difficult or impossible to obtain. We show that complex data on light distribution can be automatically obtained without conventional manual measurements. We use a mathematical model of photosynthesis parameterized by field data consisting of chlorophyll fluorescence, light response curves of carbon dioxide assimilation, and manual confirmation of Canopy Architecture and light attenuation. Model simulations show that photoinhibition alone can result in substantial reduction in carbon gain, but this is highly dependent on exact Canopy Architecture and the diurnal dynamics of photoinhibition. The use of such highly realistic Canopy reconstructions also allows us to conclude that even a moderate change in leaf angle in upper layers of the wheat Canopy led to a large increase in the number of leaves in a severely light-limited state.
Talbot J Brooks - One of the best experts on this subject based on the ideXlab platform.
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acclimation response of spring wheat in a free air co2 enrichment face atmosphere with variable soil nitrogen regimes 3 Canopy Architecture and gas exchange
Photosynthesis Research, 2000Co-Authors: Talbot J Brooks, Gerard W Wall, P J Pinter, Bruce A Kimball, R L Lamorte, Steven W Leavitt, A D Matthias, Floyd J Adamsen, Douglas J HunsakerAbstract:The response of whole-Canopy net CO2 exchange rate (CER) and Canopy Architecture to CO2 enrichment and N stress during 1996 and 1997 for open-field-grown wheat ecosystem (Triticum aestivum L. cv. Yecora Rojo) are described. Every Control (C) and FACE (F) CO2 treatment (defined as ambient and ambient +200 μmol mol−1, respectively) contained a Low- and High-N treatment. Low-N treatments constituted initial soil content amended with supplemental nitrogen applied at a rate of 70 kg N ha−1 (1996) and 15 kg N ha−1 (1997), whereas High-N treatments were supplemented with 350 kg N ha−1 (1996 and 1997). Elevated CO2 enhanced season-long carbon accumulation by 8% and 16% under Low-N and High-N, respectively. N-stress reduced season-long carbon accumulation 14% under ambient CO2, but by as much as 22% under CO2 enrichment. Averaging both years, green plant area index (GPAI) peaked approximately 76 days after planting at 7.13 for FH, 6.00 for CH, 3.89 for FL, and 3.89 for CL treatments. Leaf tip angle distribution (LTA) indicated that Low-N canopies were more erectophile than those of High-N canopies: 48° for FH, 52° for CH, and 58° for both FL and CL treatments. Temporal trends in Canopy greenness indicated a decrease in leaf chlorophyll content from the flag to flag-2 leaves of 25% for FH, 28% for CH, 17% for CL, and 33% for FL during 1997. These results indicate that significant modifications of Canopy Architecture occurs in response to both CO2 and N-stress. Optimization of Canopy Architecture may serve as a mechanism to diminish CO2 and N-stress effects on CER.
R A Richards - One of the best experts on this subject based on the ideXlab platform.
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selection for erect Canopy Architecture can increase yield and biomass of spring wheat
Field Crops Research, 2019Co-Authors: R A Richards, Colin Cavanagh, Penny RiffkinAbstract:Abstract In wheat (Triticum aestivum L.) Canopy Architecture influences light penetration into the Canopy and radiation use efficiency particularly during the period between stem elongation and anthesis which is the critical time for the determination of yield. Despite large differences in Canopy Architecture among spring wheat genotypes, ranging from erectophile to planophile upper leaves, there is little prior evidence to suggest that selection for Canopy Architecture influences yield. In this study we evaluated the variation for Canopy Architecture in a 4-way MAGIC population (n=∼ 1000 lines) developed from 4 Australian commercial spring wheats and an 8-way MAGIC population (n=∼ 300 lines) developed from 3 Australian and 5 northern hemisphere commercial wheats. The 4-way population was grown at both an irrigated and a dryland site in southern New South Wales whereas the 8-way population was grown at the irrigated site. We also measured grain yield, plant height and crop development stage at the irrigated site. Using a smaller subset of lines which we grouped into either erectophile or planophile we studied how Canopy Architecture influences grain yield and associated yield traits (above-ground biomass (AGBM), harvest index, yield components, flowering time and height). The grain yield in the latter experiments varied from 5 to 6 t ha−1. Averaged over two years and two sowing dates in each year lines that were erectophile yielded 13% more than the planophile lines and most of this yield advantage was associated with a higher AGBM (11%). Erectophile lines had 24% more grains per unit area but a 9% lower grain weight. Erectophile lines flowered 2 days later than planophile lines and they were 7 cm shorter. Lodging, although rare in these studies, was more evident in the planophile lines. In both MAGIC populations the most erectophile lines yielded 24% more grain than the most planophile lines. Mapping was conducted on the 1000 lines from the 4-way MAGIC population grown at the irrigated and the dryland site. It showed that genetic control of Canopy Architecture was complex but QTL were generally repeatable at both sites. Significant QTL were identified on most chromosomes. G x E was low for Canopy Architecture as the scores were repeatable across years (r2 = 0.85). This trait opens the way to improve wheat yields via increasing crop biomass which in the past has been largely intractable in breeding programs.