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Zheng B.Y.,China Agricultural University | Ma Y.T.,China Agricultural University | Li B.G.,China Agricultural University | Guo Y.,China Agricultural University | Deng Q.Y.,China National Hybrid Rice R and nter
Science China Earth Sciences | Year: 2011

Observations indicate that global radiation reaching the Earth's surface has gradually decreased over the past several decades (i. e., the "global dimming" phenomenon), while the fraction of diffuse radiation in global radiation has increased. It has been found that the increase in diffuse fraction significantly increases photosynthetic production in the canopy, but the mechanism has not been clarified. A three-dimensional light distribution model considering the geometry of incident radiation was employed in this study. This model was used to simulate the light distribution and potential photosynthetic production of rice canopy. The results indicate that the potential photosynthetic production of rice significantly increases in response to an increase in the diffuse fraction as long as global radiation does not decline greatly. The "fertilization effect" of diffuse radiation results from the reduction of leaf area with photosynthetic photon flux density (PPFD) below the light compensation point in response to an increasing diffuse fraction, and an increase in the leaf area with PPFD on the linear part of the light response curve. The increase in the diffuse fraction results in a significant increase in the photosynthetic rate of the upper canopy. High-performance computation is an easy-to-use and economic approach to overcome the computational constraints of the model. © 2010 Science China Press and Springer-Verlag Berlin Heidelberg. Source


Zheng B.,China Agricultural University | Ma Y.,China Agricultural University | Li B.,China Agricultural University | Guo Y.,China Agricultural University | Deng Q.,China National Hybrid Rice R and nter
Plant Growth Modeling, Simulation, Visualization and Applications, Proceedings - PMA09 | Year: 2010

Improving plant structure is pivotal for increasing the potential yield of crops. The aim of this paper was to evaluate the influence of leaf angle and leaf area index (LAI) on light interception efficiency and capacity of biomass production of rice using 3-D models. A group of virtual plant types of rice, with different combinations of leaf angles, was designed based on the 3-D data of a real rice canopy which was digitized in situ in the field at the filling stage. The results indicated that plant types with excessively steep leaves could lead a significant decrease of photosynthesis at higher solar inclination angle. An optimum LAI corresponding to the peak photosynthetic rate can be found for each of the plant type. To overcome the obstacle of heavy computing in this study, computer cluster and message passing interface were used to provide an efficient and economical way for simulating the 3-D light distribution and photosynthetic rate in rice canopies. © 2010 IEEE. Source


Li R.,Chinese University of Hong Kong | Chen J.-S.,Chinese University of Hong Kong | Yuan D.-Y.,China National Hybrid Rice R and nter | Tang L.,China National Hybrid Rice R and nter | And 4 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2010

The present study aims to identify the expression of transgene in given rice plant samples in certain conditions. To avoid external noise caused by temperature change and water-loss, field spectrum was collected with ASD field spectrometer in natural state. The study calculated the mean spectrum of samples as main data set analyzed which were controlled by inner clustering coefficient to ensure data quality. By mean spectrum, the noise from random distinctions in few individual cultivators, which could not be expressed in the class stably, could be weakened even with filtering. With the help of parameters, such as red edge and green peak, this study gave qualitative spectral differences between transgenic samples and their parents. The results show that the transgenes in rice plant were expressed and influenced the samples. Moreover, it was found that the parameters of area are more suitable for describing the differences/changes of the samples, while PRI and SR-PRI are more sensitive to indicate them. Most of the above results could be found on the continuum-removal spectrum curve of samples. These conclusive results demonstrate that hyperspectral remote sensing technique has good prospects and application potential in transgene expression detection and monitoring, especially in plant breeding process. Source


Lian-Guang L.,Hunan Academy of Agricultural science | Xin-Wei G.,Hunan Academy of Agricultural science | Yong Y.,Hunan Agricultural University | Ai-Guo H.,Hunan Academy of Agricultural science | And 2 more authors.
Journal of Ecology and Rural Environment | Year: 2012

Super hybrid rice Y Liangyou No. 1 was employed in a field experiment to investigate effects of combined application of organic and inorganic fertilizers (180 kg • hm) on yield composition and heavy metal content of the crop. Results show that based on the simulation using a fertilization rate-yield model, yield of the crop was the highest, reaching 10 084. 37 kg • hm, when 606. 75 kg • hm organic fertilizer and 288. 18 kg • hm urea were applied together, and the crop could yield an optimal economic benefit (grain yield: 9 968. 42 kg • hm) when 202. 32 kg • hm organic feritilizer and 353. 17 kg • hm urea were applied together. No significant difference was observed in Cd content of the plant between treatments different in ratio of the organic and inorganic fertilizer combination. However, among the six treatiments, the one (600 kg • hm organic fertilizer and 289. 27 kg • hm urea) was the highest in crop yield and the lowest in plant Cr content. Source


Zhang T.,Sichuan Academy of Agricultural science | Zhang T.,Luzhou Branch of Chinese National Center for Rice Improvement | Ni X.-L.,Sichuan Academy of Agricultural science | Ni X.-L.,Chongqing University | And 12 more authors.
Rice Science | Year: 2010

The genetic distances among 18 cytoplasmic male sterile lines and 11 restorer lines were analyzed with molecular markers derived from yield-related functional genes. The correlation between parental genetic distance and heterosis was investigated by analyzing the performance of 47 combinations. The results showed that the genetic distance was significantly correlated with yield heterosis (r=0.29*), but not significantly correlated with heterosis for other traits, such as number of effective panicles per plant, seed setting rate, 1000-grain weight, number of grains per panicle and theoretical yield. However, the correlation coefficient was so small that the parental genetic distance could not to be used to predict heterosis. © 2010 China National Rice Research Institute. Source

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