The impacts of different 03 concentration on the biomass and yield of rice were studied by using OTC-1 open-top chambers. Experimental treatments included the activated charcoal-filtered air. (CFA), 50 nl/L (CF50), 10...The impacts of different 03 concentration on the biomass and yield of rice were studied by using OTC-1 open-top chambers. Experimental treatments included the activated charcoal-filtered air. (CFA), 50 nl/L (CF50), 100 nl/L ( CF100) and 200 nl/L (CF200) concentrations of O-3. The O-3 treatments significantly decreased the total biomass per plant. The. elevated O-3 exposure resulted in a more decrease in the root growth than in the shoot growth. Assessments of yield characteristics at the final harvest revealed an O-3-induced decrease in the number of grains per plant, resulting from fewer ears per plant, fewer grains per ear and more unfilled grains per ear. The 1000 grain dry weight and the harvest index (HI) were not changed significantly under 50 nl/L or 100 nl/L O-3 exposure, but reduced by 17.0% and 4.8% by 200nl/L O-3 treatment, respectively. Compared to the CFA treatment, CF50, CF100 and CF200 treatments caused a 8.2%, 26.1%, 49.1% decrease of the grain yield per plant, and a 14.2%, 31.7%, 51.7% decrease of the total biomass per plant, respectively. Linear regression showed that the 7h - daily mean O-3 concentration exposure for 3 months ( July-September) and AOT40 ( cunulative exposure accumulation over threshold 40 nl/L) were well correlated with the relative grain yield. A yield loss of 10% was estimated to be at 46.9 nl/L O-3 for 7h-daily mean O-3 concentration exposure or at 12930nl/(L(.)h) O-3 for AOT40.展开更多
To understand the changes in yield, harvest index （HI） and biomass of aboveground parts of rice, 33 japonica rice cultivars released from 1958 to 2005 were planted. During the 47 years, the grain yield increased fro...To understand the changes in yield, harvest index （HI） and biomass of aboveground parts of rice, 33 japonica rice cultivars released from 1958 to 2005 were planted. During the 47 years, the grain yield increased from 9 118.36 to 15 060.1 kg/hm2 and HI from 0.46 to 0.55. In the genetic improvement, the total number of tillers per plant decreased, and the biomass per unit area slightly increased at the harvest stage. The increases of yield and HI resulted from the increased biomasses of effective tillers and single stem, and the increase of biomass per stem was related to the increased biomasses of different organs along with the genetic improvement. The stem and sheath biomass at heading and the leaf biomass at 30 days after heading showed the highest increase, up by 75.17% and 49.94%, respectively. The biomasses of leaf and stem-sheath at 10 days after heading, and biomass per stem at 30 days after heading were obviously correlated with the yield. The results indicate that the genetic improvement has resulted in the increase of yield and HI. This increase is correlated with the decrease of total tiller number per plant, and increase of biomasses of effective tillers and single stem. The leaf biomass after heading and the stem and sheath biomass at 10 days after heading can be used as selection criteria for breeding high yielding rice cultivars.展开更多
Biomass production is important in increasing yield not only for food but also for bio-fuel production that depends on high dry matter. Due to climate change, occurrence of drought may be prevalent and this affects bo...Biomass production is important in increasing yield not only for food but also for bio-fuel production that depends on high dry matter. Due to climate change, occurrence of drought may be prevalent and this affects both grain and biomass yields in crops including rice. The objectives of this study were to determine the performance of selected high biomass breeding rice lines to different levels of drought and use several drought tolerance indices to identify best genotypes that could be grown in unfavorable water stressed areas. A rainfed and flooded trial was conducted to evaluate 20 selected breeding lines for biomass production and ten entries from the same set were grown in the greenhouse at three different field capacities (FC, 50%, 75%, 100%). Most of the genotypes performed well under non-stressed conditions (flooded and 100% FC) but some genotypes performed well in water stressed condition. The plants had lower plant height, tiller plant-1, and total biomass at maturity under rainfed conditions and their flowering was delayed compared to flooded conditions. In the greenhouse, water stress slowed the rate of increase in height, and produced lower shoot and root weight, percent dry matter (% DM) and total biomass. However, drought enhanced the rate of tiller production. Two genotypes were found to more tolerant to drought stress and could be used for cultivation under water stress condition to get optimum biomass yields. These genotypes can be identified using drought tolerance indices, particularly stress tolerance index (STI), geometric mean productivity (GMP), mean productivity (MP) and harmonic mean (HARM), as these have a similar ability to separate drought sensitive and tolerant genotypes. Genetic and molecular analyses, and detailed characterization of these genotypes will help understand their inheritance pattern and the number of genes controlling the traits and determine specific leaves and root traits important in developing high biomass rice.展开更多
Nanocrystalline cellulose(NCC) was produced from rice husk biomass(Oryza sativa) by a chemical extraction process to explore the potential aspect of agro-waste biomass in Australia. In this work, the delignified rice ...Nanocrystalline cellulose(NCC) was produced from rice husk biomass(Oryza sativa) by a chemical extraction process to explore the potential aspect of agro-waste biomass in Australia. In this work, the delignified rice husk pulp(D-RHP) was produced by alkaline delignification of raw rice husk biomass(R-RHB) using 4 mol·L^(-1) alkali solutions(Na OH) in a jacketed glass reactor under specific experimental conditions. D-RHP was bleached using 15% sodium hypochlorite, and the bleached rice husk pulp was coded as B-RHP. Finally,raw suspension of NCC was produced by the acid hydrolysis of B-RHP using 4 mol·L^(-1) sulphuric acid. The raw suspension of NCC was neutralized by a buffer solution and analyzed by TAPPI, FT-IR, XRD, SEM, AFM, and TEM. FT-IR spectra of NCC are different to R-RHB but similar with B-RHP and D-RHP. From XRD results, the crystallinity of NCC was found to be approximately 65%. In AFM analysis particle thicknesses have been confirmed to be in the range of(25 ± 15.14) nm or(27 ± 15.14) nm which is almost the same. From TEM analysis particle dimensions have been confirmed to be in the range of(50 ± 29.38) nm width and(550 ± 302.75) nm length with the aspect ratio ~ 11:1(length/diameter) at a 500 nm scale bar. On the other hand, at a 200 nm scale bar the particle dimensions have been confirmed to be in the range of(35 ± 17) nm width and(275 ± 151.38)nm length with the aspect ratio ~ 8:1. The aspect ratio of individual crystalline domain was determined in TEM analysis which is 10:1(100/10). Therefore the aspect ratios and dimensions of nanoparticles in NCC suspension are almost the same and in nano-meter scale, as confirmed from both AFM and TEM results. The yield of NCC from B-RHP was found to be approximately 95%, and the recovery of cellulose from R-RHB is about 90%.展开更多
To quantify the relationships between rice plant architecture parameters and the corresponding organ biomass, and to research on functional structural plant models of rice plant, this paper presented a biomass-based m...To quantify the relationships between rice plant architecture parameters and the corresponding organ biomass, and to research on functional structural plant models of rice plant, this paper presented a biomass-based model of aboveground architectural parameters of rice （Oryza sativa L.） in the young seedling stage, designed to explain effects of cultivars and environmental conditions on rice aboveground morphogenesis at the individual leaf level. Various model variables, including biomass of blade and blade length, were parameterized for rice based on data derived from an outdoor experiment with rice cv. Liangyou 108, 86You 8, Nanjing 43, and Yangdao 6. The organ dimensions of rice aboveground were modelled taking corresponding organ biomass as an independent variable. Various variables in rice showed marked consistency in observation and simulation, suggesting possibilities for a general rice architectural model in the young seedling stage. Our descriptive model was suitable for our objective. However, they can set the stage for connection to physiological model via biomass and development of functional structural rice models （FSRM）, and start with the localized production and partitioning of assimilates as affected by abiotic growth factors. The finding of biomass-based rice architectural parameter models also can be used in morphological models of blade, sheath, and tiller of the other stages in rice life.展开更多
A pot experiment was conducted under submerged conditions with hybrid rice Zhenong 7 to study the variation in the soil microbial biomass carbon （Cmic）, soil microbial biomass nitrogen （Nmic）, soil respiration rat...A pot experiment was conducted under submerged conditions with hybrid rice Zhenong 7 to study the variation in the soil microbial biomass carbon （Cmic）, soil microbial biomass nitrogen （Nmic）, soil respiration rate, soil microbial metabolic quotient, soil enzyme activities, chlorophyll content, proline content and peroxidase activity （POD） in rice leaf at different growth stages. The soil Cmic, Nmic and soil respiration rate significantly increased at the early stage and then declined during rice growth, but ascended slightly at maturity. However, soil metabolic quotient declined at all the stages. Soil urease activity increased at first and then decreased, while acid phosphatase and dehydrogenase activities descended before ascended and then descended again. Soil urease activity and acid phosphatase activity showed a peak value at the tillering stage about 30 days after rice transplanting, but the peak value of dehydrogenase activity emerged at about 50 days after rice transplanting and the three soil enzymatic activities were significantly different at the different developmental stages. As rice growing, chlorophyll content in rice leaf descended at the early stage then ascended and a peak value appeared at about the 70th after rice transplanting, after that declined drastically, while POD activity increased gradually, but proline content declined gradually. There was a slight relation between rice physiological indices and soil biochemical indices, which indicated that soil biochemical characteristics were affected significantly by rice growth in the interaction system of the rice. soil and microorganisms.展开更多
Field measurements of methane emission from rice paddies were made in Nanjing, China and in Texas, USA, respectively. Soil temperature at approximately 10 cm depth of the flooded soils was automatically recorded. Abov...Field measurements of methane emission from rice paddies were made in Nanjing, China and in Texas, USA, respectively. Soil temperature at approximately 10 cm depth of the flooded soils was automatically recorded. Aboveground biomass of rice crop was measured approximately every 10 days in Nanjing and every other week in Texas. Seasonal variation of soil temperature in Nanjing was quite wide with a magnitude of 15.3°C and that in Texas was narrow with a magnitude of 2.9°C. Analysis of methane emission fluxes against soil temperature and rice biomass production demonstrated that the seasonal course of methane emission in Nanjing was mostly attributed to soil temperature changes, while that in Texas was mainly related to rice biomass production. We concluded that under the permanent flooding condition, the seasonal trend of methane emission would be determined by the soil temperature where there was a wide variation of soil temperature, and the seasonal trend would be mainly determined by rice biomass production if there are no additional organic matter inputs and the variation of soil temperature over the rice growing season is small. Key words CH4 emission - Rice paddies - Rice biomass production - Soil temperature This work was supported by grants from TECO/NASA, the United States, the Hundred Talents Program, Chinese Academy of Sciences and the National Key Basic Research Development Foundation (approved # G1999011805), China.展开更多
The field experiment was conducted in 2005 and 2006 at Northern Japonica Rice Cultivation and Breeding Research Center, Shenyang Agricultural University,Shenyang, northeast China. Shennong 265 (typical erect panicle r...The field experiment was conducted in 2005 and 2006 at Northern Japonica Rice Cultivation and Breeding Research Center, Shenyang Agricultural University,Shenyang, northeast China. Shennong 265 (typical erect panicle rice cultivar), and Liaojing 294 (traditional semi-erect panicle rice cultivar) were grown under different N rates to assess N uptake and N use efficiency. Nitrgen (N) uptake of two rice cultivars increased in their response to N improvement. Grain N of Liaojing 294 predominantly came from root absorption on low N treatments, while grain N of Shennong 265 mainly came from root absorption and had less N re-transferring from vegetative organs under high N rates. Shennong 265 produced less N uptake before heading and more N uptake after heading than Liaojing 294. GY was highly related with N fertilizer rate (r2 = 0.870** for Shennong 265, r2 = 0.613* for Liaojing 294). Shennong 265 was a N-unefficient genotype, since it produced low yield at low N levels and responded well to N application. Liaojing 294 was a N-efficient genotype producing high yield at both low and high N rates. NNG and NFUE exhibited positive correlation with N application rates, but NUEPG showed negative correlation with N application rates;GY as well as BIO and N uses efficiency parameters (TN, NNG, NFUE) which were all positively correlate, while the correlation between GY as well as BIO and the other N efficiency indicators expressed negative correlation. The relationship between GY and TN as well as BIO and TN was observed with significant difference (r2 = 0.824**, r2 = -0.858**).展开更多
To understand the wild Oryza genome effect on photosynthesis and its relation to total dry matter accumulation in an elite rice variety, a set of 40 stable introgression lines(ILs) BC_3F_8 derived from a cross of Oryz...To understand the wild Oryza genome effect on photosynthesis and its relation to total dry matter accumulation in an elite rice variety, a set of 40 stable introgression lines(ILs) BC_3F_8 derived from a cross of Oryza sativa(KMR3) × Oryza rufipogon(WR120) were grown under well watered conditions. Leaf gas exchange measurements and leaf chlorophyll estimates were conducted at the flowering stage. The results revealed significant variations in net photosynthetic rate(Pn), transpiration rate(E), transpiration efficiency(Pn/E) and carboxylation efficiency(Pn/C_i). Pn showed significant positive correlation with E, stomatal conductance(g_s), Pn/C_i and total canopy dry matter. Specific leaf area and leaf thickness were not significantly correlated with Pn. Thirty-seven out of 40 ILs showed higher Pn than KMR3 [11.28 μmol/(m^2·s)], and 20 ILs showed higher Pn than WR120 [15.08 μmol/(m^2·s)]. The line IL194 showed the highest Pn [21.62 μmol/(m^2·s)] with increased total canopy dry matter followed by lines IL381, IL106, IL363-12, IL198, IL86-18 and IL50, which exhibited Pn above 18.0 μmol/(m^2·s). The ILs with enhanced Pn are a potential source for developing rice varieties and hybrids with higher biomass and yield.展开更多
To compare the grain yield and growth behaviors of hybrid rice, field experiments were conducted in a subtropical environment in Changsha, Hunan Province, China, and in two tropical environments in Gazipur and Habigan...To compare the grain yield and growth behaviors of hybrid rice, field experiments were conducted in a subtropical environment in Changsha, Hunan Province, China, and in two tropical environments in Gazipur and Habiganj in Bangladesh during 2009 to 2011. Three hybrid rice cultivars were grown under three nitrogen （N） management treatments in each experiment. The results showed that grain yield was significantly affected by locations, N treatments and their interaction but not by cultivars. Changsha produced 8-58% higher grain yields than Bangladesh locations. Sink size （spikelet number per unit land area） was responsible for these yield differences. Larger panicle size （spikelet number per panicle） contributed to greater sink size in Changsha. Aboveground total biomass was greater in Changsha than in Bangladesh locations, whereas harvest index was higher in Bangladesh locations than in Changsha. Crop growth rate （CGR） was greater at Changsha than Bangladesh locations during vegetative phase, while the difference was relatively small and not consistent during the later growth phases. Higher leaf area index and leaf area duration were partly responsible for the greater CGR in Changsha. Real-time N management （RTNM） produced lower grain yields than fixed-time N management in more than half of the experiments. Our study suggested that further improvement in rice yield in the tropical environments similar to those of Bangladesh will depend mainly on the ability to increase panicle size as well as CGR during vegetative phase, and the chlorophyll meter threshold value used in RTNM needs to be modified according to environmental conditions and cultivar characteristics to achieve a desirable grain yield.展开更多
The field experiments were conducted to investigate the growth and physiological responses of six super hybrid rice combinations to two planting methods, transplanting （TP） and direct seeding （DS） during 2006-2007...The field experiments were conducted to investigate the growth and physiological responses of six super hybrid rice combinations to two planting methods, transplanting （TP） and direct seeding （DS） during 2006-2007 and 2007-2008. The 1000-grain weight and number of tillers per plant at the early growth stage, the maximum quantum yield of PSII （Fv/Fm） and transpiration rate （Tr） were higher in DS plants than in TP ones, whereas the grain yield, number of panicles per square meter, seed setting rate, net photosynthetic rate （Po） and stomatal conductance were lower in DS plants. However, little difference was detected in number of grains per panicle, stem （shoot） and leaf weight between the combinations in the two planting methods. The responses of plant growth and physiological traits to planting method differed greatly among the six combinations. In both planting methods, Chouyou 58 and Yongyou 6 had the highest and lowest panicle biomass and Pn, respectively. The higher yield of Chunyou 58 was associated with more numbers of panicles per square meter and grains per panicle in both planting methods. The results indicate that lower grain yield in DS relative to TP is attributed to more excessive tillers at the early stage, lower leaf biomass and photosynthetic rate at the late stage.展开更多
The interplanting with zero-tillage of rice, i.e. direct sowing rice 10-20 days before wheat harvesting, and remaining about 30-cm high stubble after cutting wheat or rice with no tillage, is a new cultivation technol...The interplanting with zero-tillage of rice, i.e. direct sowing rice 10-20 days before wheat harvesting, and remaining about 30-cm high stubble after cutting wheat or rice with no tillage, is a new cultivation technology in wheat-rice rotation system. To study the effects of interplanting with zero tillage and straw manure on rice growth and quality, an experiment was conducted in a wheat-rotation rotation system. Four treatments, i.e. ZIS （Zero-tillage, straw manure and rice interplanting）, Zt （Zero-tillage, no straw manure and rice interplanting）, PTS （Plowing tillage, straw manure and rice transplanting）, and PT （Plowing tillage, no straw manure and rice transplanting）, were used. ZtS reduced plant height, leaf area per plant and the biomass of rice plants, but the biomass accumulation of rice at the late stage was quicker than that under conventional transplanting cultivation. In the first year （2002）, there was no significant difference in rice yield among the four treatments. However, rice yield decreased in interplanting with zero-tillage in the second year （2003）. Compared with the transplanting treatments, the number of filled grains per panicle decreased but l000-grain weight increased in interplanting with zero-tillage, which were the main factors resulting in higher yield, tnterplanting with zero-tillage improved the milling and appearance qualities of rice. The rates of milled and head rice increased while chalky rice rate and chalkiness decreased in interplanting with zero-tillage. Zero-tillage and interplanting also affected rice nutritional and cooking qualities. In 2002, ZIS showed raised protein content, decreased amylose content, softer gel consistency, resulting in improved rice quality. In 2003, zero-tillage and interplanting decreased protein content and showed similar amylose content as compared with transplanting treatments. Moreover, protein content in PTS was obviously increased in comparison with the other three treatments. The rice in interplanting with zero-tillage treatments had higher peak viscosity and breakdown, lower setback, showing better rice taste quality. The straw manure had no significant effect on rice viscosity under interplanting with zero-tillage, but had the negative influence on the rice taste quality under transplanting with plowing tillage.展开更多
文摘The impacts of different 03 concentration on the biomass and yield of rice were studied by using OTC-1 open-top chambers. Experimental treatments included the activated charcoal-filtered air. (CFA), 50 nl/L (CF50), 100 nl/L ( CF100) and 200 nl/L (CF200) concentrations of O-3. The O-3 treatments significantly decreased the total biomass per plant. The. elevated O-3 exposure resulted in a more decrease in the root growth than in the shoot growth. Assessments of yield characteristics at the final harvest revealed an O-3-induced decrease in the number of grains per plant, resulting from fewer ears per plant, fewer grains per ear and more unfilled grains per ear. The 1000 grain dry weight and the harvest index (HI) were not changed significantly under 50 nl/L or 100 nl/L O-3 exposure, but reduced by 17.0% and 4.8% by 200nl/L O-3 treatment, respectively. Compared to the CFA treatment, CF50, CF100 and CF200 treatments caused a 8.2%, 26.1%, 49.1% decrease of the grain yield per plant, and a 14.2%, 31.7%, 51.7% decrease of the total biomass per plant, respectively. Linear regression showed that the 7h - daily mean O-3 concentration exposure for 3 months ( July-September) and AOT40 ( cunulative exposure accumulation over threshold 40 nl/L) were well correlated with the relative grain yield. A yield loss of 10% was estimated to be at 46.9 nl/L O-3 for 7h-daily mean O-3 concentration exposure or at 12930nl/(L(.)h) O-3 for AOT40.
基金supported by the National Jump Plan of Agriculture Science and Technology, China (Grant No. 200754)the Science and Technology Department of Key Projects of Jilin Province, China (Grant No. 20080201)
文摘To understand the changes in yield, harvest index （HI） and biomass of aboveground parts of rice, 33 japonica rice cultivars released from 1958 to 2005 were planted. During the 47 years, the grain yield increased from 9 118.36 to 15 060.1 kg/hm2 and HI from 0.46 to 0.55. In the genetic improvement, the total number of tillers per plant decreased, and the biomass per unit area slightly increased at the harvest stage. The increases of yield and HI resulted from the increased biomasses of effective tillers and single stem, and the increase of biomass per stem was related to the increased biomasses of different organs along with the genetic improvement. The stem and sheath biomass at heading and the leaf biomass at 30 days after heading showed the highest increase, up by 75.17% and 49.94%, respectively. The biomasses of leaf and stem-sheath at 10 days after heading, and biomass per stem at 30 days after heading were obviously correlated with the yield. The results indicate that the genetic improvement has resulted in the increase of yield and HI. This increase is correlated with the decrease of total tiller number per plant, and increase of biomasses of effective tillers and single stem. The leaf biomass after heading and the stem and sheath biomass at 10 days after heading can be used as selection criteria for breeding high yielding rice cultivars.
文摘Biomass production is important in increasing yield not only for food but also for bio-fuel production that depends on high dry matter. Due to climate change, occurrence of drought may be prevalent and this affects both grain and biomass yields in crops including rice. The objectives of this study were to determine the performance of selected high biomass breeding rice lines to different levels of drought and use several drought tolerance indices to identify best genotypes that could be grown in unfavorable water stressed areas. A rainfed and flooded trial was conducted to evaluate 20 selected breeding lines for biomass production and ten entries from the same set were grown in the greenhouse at three different field capacities (FC, 50%, 75%, 100%). Most of the genotypes performed well under non-stressed conditions (flooded and 100% FC) but some genotypes performed well in water stressed condition. The plants had lower plant height, tiller plant-1, and total biomass at maturity under rainfed conditions and their flowering was delayed compared to flooded conditions. In the greenhouse, water stress slowed the rate of increase in height, and produced lower shoot and root weight, percent dry matter (% DM) and total biomass. However, drought enhanced the rate of tiller production. Two genotypes were found to more tolerant to drought stress and could be used for cultivation under water stress condition to get optimum biomass yields. These genotypes can be identified using drought tolerance indices, particularly stress tolerance index (STI), geometric mean productivity (GMP), mean productivity (MP) and harmonic mean (HARM), as these have a similar ability to separate drought sensitive and tolerant genotypes. Genetic and molecular analyses, and detailed characterization of these genotypes will help understand their inheritance pattern and the number of genes controlling the traits and determine specific leaves and root traits important in developing high biomass rice.
基金funded by RMIT University, Melbourne, VIC 3001, Australia
文摘Nanocrystalline cellulose(NCC) was produced from rice husk biomass(Oryza sativa) by a chemical extraction process to explore the potential aspect of agro-waste biomass in Australia. In this work, the delignified rice husk pulp(D-RHP) was produced by alkaline delignification of raw rice husk biomass(R-RHB) using 4 mol·L^(-1) alkali solutions(Na OH) in a jacketed glass reactor under specific experimental conditions. D-RHP was bleached using 15% sodium hypochlorite, and the bleached rice husk pulp was coded as B-RHP. Finally,raw suspension of NCC was produced by the acid hydrolysis of B-RHP using 4 mol·L^(-1) sulphuric acid. The raw suspension of NCC was neutralized by a buffer solution and analyzed by TAPPI, FT-IR, XRD, SEM, AFM, and TEM. FT-IR spectra of NCC are different to R-RHB but similar with B-RHP and D-RHP. From XRD results, the crystallinity of NCC was found to be approximately 65%. In AFM analysis particle thicknesses have been confirmed to be in the range of(25 ± 15.14) nm or(27 ± 15.14) nm which is almost the same. From TEM analysis particle dimensions have been confirmed to be in the range of(50 ± 29.38) nm width and(550 ± 302.75) nm length with the aspect ratio ~ 11:1(length/diameter) at a 500 nm scale bar. On the other hand, at a 200 nm scale bar the particle dimensions have been confirmed to be in the range of(35 ± 17) nm width and(275 ± 151.38)nm length with the aspect ratio ~ 8:1. The aspect ratio of individual crystalline domain was determined in TEM analysis which is 10:1(100/10). Therefore the aspect ratios and dimensions of nanoparticles in NCC suspension are almost the same and in nano-meter scale, as confirmed from both AFM and TEM results. The yield of NCC from B-RHP was found to be approximately 95%, and the recovery of cellulose from R-RHB is about 90%.
基金supported by the National High-Tech R&D Program of China(2006AA10Z230, 2006AA10Z219-1)the National Natural Science Foundation of China (31171455)+3 种基金the Jiangsu Province Agricultural Scientific Technology Innovation Fund,China (CX(10)221)the Jiangsu Province Postdoctoral Research Program, China (5910907)the No-Profit Industry(Meteorology) Research Program, China (GYHY201006027,GYHY201106027)the Jiangsu Government Scholar-ship for Overseas Studies, Jiangsu Academy of Agricultural Sciences Founding, China (6510733)
文摘To quantify the relationships between rice plant architecture parameters and the corresponding organ biomass, and to research on functional structural plant models of rice plant, this paper presented a biomass-based model of aboveground architectural parameters of rice （Oryza sativa L.） in the young seedling stage, designed to explain effects of cultivars and environmental conditions on rice aboveground morphogenesis at the individual leaf level. Various model variables, including biomass of blade and blade length, were parameterized for rice based on data derived from an outdoor experiment with rice cv. Liangyou 108, 86You 8, Nanjing 43, and Yangdao 6. The organ dimensions of rice aboveground were modelled taking corresponding organ biomass as an independent variable. Various variables in rice showed marked consistency in observation and simulation, suggesting possibilities for a general rice architectural model in the young seedling stage. Our descriptive model was suitable for our objective. However, they can set the stage for connection to physiological model via biomass and development of functional structural rice models （FSRM）, and start with the localized production and partitioning of assimilates as affected by abiotic growth factors. The finding of biomass-based rice architectural parameter models also can be used in morphological models of blade, sheath, and tiller of the other stages in rice life.
基金the National Natural Science Foundation of China (40201026 , 40371063) China National Basic Research Program (2002CB410804).
文摘A pot experiment was conducted under submerged conditions with hybrid rice Zhenong 7 to study the variation in the soil microbial biomass carbon （Cmic）, soil microbial biomass nitrogen （Nmic）, soil respiration rate, soil microbial metabolic quotient, soil enzyme activities, chlorophyll content, proline content and peroxidase activity （POD） in rice leaf at different growth stages. The soil Cmic, Nmic and soil respiration rate significantly increased at the early stage and then declined during rice growth, but ascended slightly at maturity. However, soil metabolic quotient declined at all the stages. Soil urease activity increased at first and then decreased, while acid phosphatase and dehydrogenase activities descended before ascended and then descended again. Soil urease activity and acid phosphatase activity showed a peak value at the tillering stage about 30 days after rice transplanting, but the peak value of dehydrogenase activity emerged at about 50 days after rice transplanting and the three soil enzymatic activities were significantly different at the different developmental stages. As rice growing, chlorophyll content in rice leaf descended at the early stage then ascended and a peak value appeared at about the 70th after rice transplanting, after that declined drastically, while POD activity increased gradually, but proline content declined gradually. There was a slight relation between rice physiological indices and soil biochemical indices, which indicated that soil biochemical characteristics were affected significantly by rice growth in the interaction system of the rice. soil and microorganisms.
基金supported by grants from TECO/ NASA, the United States, the Hundred TalentsProgram, Chinese Academy of Sciences the Nation
文摘Field measurements of methane emission from rice paddies were made in Nanjing, China and in Texas, USA, respectively. Soil temperature at approximately 10 cm depth of the flooded soils was automatically recorded. Aboveground biomass of rice crop was measured approximately every 10 days in Nanjing and every other week in Texas. Seasonal variation of soil temperature in Nanjing was quite wide with a magnitude of 15.3°C and that in Texas was narrow with a magnitude of 2.9°C. Analysis of methane emission fluxes against soil temperature and rice biomass production demonstrated that the seasonal course of methane emission in Nanjing was mostly attributed to soil temperature changes, while that in Texas was mainly related to rice biomass production. We concluded that under the permanent flooding condition, the seasonal trend of methane emission would be determined by the soil temperature where there was a wide variation of soil temperature, and the seasonal trend would be mainly determined by rice biomass production if there are no additional organic matter inputs and the variation of soil temperature over the rice growing season is small. Key words CH4 emission - Rice paddies - Rice biomass production - Soil temperature This work was supported by grants from TECO/NASA, the United States, the Hundred Talents Program, Chinese Academy of Sciences and the National Key Basic Research Development Foundation (approved # G1999011805), China.
文摘The field experiment was conducted in 2005 and 2006 at Northern Japonica Rice Cultivation and Breeding Research Center, Shenyang Agricultural University,Shenyang, northeast China. Shennong 265 (typical erect panicle rice cultivar), and Liaojing 294 (traditional semi-erect panicle rice cultivar) were grown under different N rates to assess N uptake and N use efficiency. Nitrgen (N) uptake of two rice cultivars increased in their response to N improvement. Grain N of Liaojing 294 predominantly came from root absorption on low N treatments, while grain N of Shennong 265 mainly came from root absorption and had less N re-transferring from vegetative organs under high N rates. Shennong 265 produced less N uptake before heading and more N uptake after heading than Liaojing 294. GY was highly related with N fertilizer rate (r2 = 0.870** for Shennong 265, r2 = 0.613* for Liaojing 294). Shennong 265 was a N-unefficient genotype, since it produced low yield at low N levels and responded well to N application. Liaojing 294 was a N-efficient genotype producing high yield at both low and high N rates. NNG and NFUE exhibited positive correlation with N application rates, but NUEPG showed negative correlation with N application rates;GY as well as BIO and N uses efficiency parameters (TN, NNG, NFUE) which were all positively correlate, while the correlation between GY as well as BIO and the other N efficiency indicators expressed negative correlation. The relationship between GY and TN as well as BIO and TN was observed with significant difference (r2 = 0.824**, r2 = -0.858**).
基金supported by a grant from the Department of Biotechnology,Government of India,DBT(No.BT/AB/FG-2(PHII)IA/2009)
文摘To understand the wild Oryza genome effect on photosynthesis and its relation to total dry matter accumulation in an elite rice variety, a set of 40 stable introgression lines(ILs) BC_3F_8 derived from a cross of Oryza sativa(KMR3) × Oryza rufipogon(WR120) were grown under well watered conditions. Leaf gas exchange measurements and leaf chlorophyll estimates were conducted at the flowering stage. The results revealed significant variations in net photosynthetic rate(Pn), transpiration rate(E), transpiration efficiency(Pn/E) and carboxylation efficiency(Pn/C_i). Pn showed significant positive correlation with E, stomatal conductance(g_s), Pn/C_i and total canopy dry matter. Specific leaf area and leaf thickness were not significantly correlated with Pn. Thirty-seven out of 40 ILs showed higher Pn than KMR3 [11.28 μmol/(m^2·s)], and 20 ILs showed higher Pn than WR120 [15.08 μmol/(m^2·s)]. The line IL194 showed the highest Pn [21.62 μmol/(m^2·s)] with increased total canopy dry matter followed by lines IL381, IL106, IL363-12, IL198, IL86-18 and IL50, which exhibited Pn above 18.0 μmol/(m^2·s). The ILs with enhanced Pn are a potential source for developing rice varieties and hybrids with higher biomass and yield.
基金supported by the National Basic Research Program of China (2009CB118603)the Green Super Rice (GSR) Project from the International Rice Research Institute (IRRI) for South Asia+1 种基金Project was completed through the generous cooperation of Hunan Agricultural University, Changsha, Hunan, Chinathe Bangladesh Rice Research Institute (BRRI)
文摘To compare the grain yield and growth behaviors of hybrid rice, field experiments were conducted in a subtropical environment in Changsha, Hunan Province, China, and in two tropical environments in Gazipur and Habiganj in Bangladesh during 2009 to 2011. Three hybrid rice cultivars were grown under three nitrogen （N） management treatments in each experiment. The results showed that grain yield was significantly affected by locations, N treatments and their interaction but not by cultivars. Changsha produced 8-58% higher grain yields than Bangladesh locations. Sink size （spikelet number per unit land area） was responsible for these yield differences. Larger panicle size （spikelet number per panicle） contributed to greater sink size in Changsha. Aboveground total biomass was greater in Changsha than in Bangladesh locations, whereas harvest index was higher in Bangladesh locations than in Changsha. Crop growth rate （CGR） was greater at Changsha than Bangladesh locations during vegetative phase, while the difference was relatively small and not consistent during the later growth phases. Higher leaf area index and leaf area duration were partly responsible for the greater CGR in Changsha. Real-time N management （RTNM） produced lower grain yields than fixed-time N management in more than half of the experiments. Our study suggested that further improvement in rice yield in the tropical environments similar to those of Bangladesh will depend mainly on the ability to increase panicle size as well as CGR during vegetative phase, and the chlorophyll meter threshold value used in RTNM needs to be modified according to environmental conditions and cultivar characteristics to achieve a desirable grain yield.
基金We appreciate the Department of Science and Technology of Zhejiang,China for its financial support (Grant No.2005C12024)
文摘The field experiments were conducted to investigate the growth and physiological responses of six super hybrid rice combinations to two planting methods, transplanting （TP） and direct seeding （DS） during 2006-2007 and 2007-2008. The 1000-grain weight and number of tillers per plant at the early growth stage, the maximum quantum yield of PSII （Fv/Fm） and transpiration rate （Tr） were higher in DS plants than in TP ones, whereas the grain yield, number of panicles per square meter, seed setting rate, net photosynthetic rate （Po） and stomatal conductance were lower in DS plants. However, little difference was detected in number of grains per panicle, stem （shoot） and leaf weight between the combinations in the two planting methods. The responses of plant growth and physiological traits to planting method differed greatly among the six combinations. In both planting methods, Chouyou 58 and Yongyou 6 had the highest and lowest panicle biomass and Pn, respectively. The higher yield of Chunyou 58 was associated with more numbers of panicles per square meter and grains per panicle in both planting methods. The results indicate that lower grain yield in DS relative to TP is attributed to more excessive tillers at the early stage, lower leaf biomass and photosynthetic rate at the late stage.
文摘The interplanting with zero-tillage of rice, i.e. direct sowing rice 10-20 days before wheat harvesting, and remaining about 30-cm high stubble after cutting wheat or rice with no tillage, is a new cultivation technology in wheat-rice rotation system. To study the effects of interplanting with zero tillage and straw manure on rice growth and quality, an experiment was conducted in a wheat-rotation rotation system. Four treatments, i.e. ZIS （Zero-tillage, straw manure and rice interplanting）, Zt （Zero-tillage, no straw manure and rice interplanting）, PTS （Plowing tillage, straw manure and rice transplanting）, and PT （Plowing tillage, no straw manure and rice transplanting）, were used. ZtS reduced plant height, leaf area per plant and the biomass of rice plants, but the biomass accumulation of rice at the late stage was quicker than that under conventional transplanting cultivation. In the first year （2002）, there was no significant difference in rice yield among the four treatments. However, rice yield decreased in interplanting with zero-tillage in the second year （2003）. Compared with the transplanting treatments, the number of filled grains per panicle decreased but l000-grain weight increased in interplanting with zero-tillage, which were the main factors resulting in higher yield, tnterplanting with zero-tillage improved the milling and appearance qualities of rice. The rates of milled and head rice increased while chalky rice rate and chalkiness decreased in interplanting with zero-tillage. Zero-tillage and interplanting also affected rice nutritional and cooking qualities. In 2002, ZIS showed raised protein content, decreased amylose content, softer gel consistency, resulting in improved rice quality. In 2003, zero-tillage and interplanting decreased protein content and showed similar amylose content as compared with transplanting treatments. Moreover, protein content in PTS was obviously increased in comparison with the other three treatments. The rice in interplanting with zero-tillage treatments had higher peak viscosity and breakdown, lower setback, showing better rice taste quality. The straw manure had no significant effect on rice viscosity under interplanting with zero-tillage, but had the negative influence on the rice taste quality under transplanting with plowing tillage.
