Water-saving and drought-resistance upland rice has become a preferable choice for cotton farmlands ready for changing crops or paddy fields with water in short,because simplified and mechanical cultivation can be app...Water-saving and drought-resistance upland rice has become a preferable choice for cotton farmlands ready for changing crops or paddy fields with water in short,because simplified and mechanical cultivation can be applied for the rice varieties of drought resistance and high yield.At present,it has been applied with an area of 400 000 hm2 in Hunan Province and the area continues growing.The research bred and introduced the relevant cultivation technology standard applicable to local water-saving and drought-resistance rice varieties in order to improve farmer＇s benefits.展开更多
To study the effects of long-term no-tillage direct seeding mode on rice yield and the soil physiochemical property in a rice-rapeseed rotation system, a comparative experiment with a water-saving and drought-resistan...To study the effects of long-term no-tillage direct seeding mode on rice yield and the soil physiochemical property in a rice-rapeseed rotation system, a comparative experiment with a water-saving and drought-resistance rice （WDR） variety and a double low rapeseed variety as materials was conducted under no-tillage direct seeding （NTDS） mode and conventional tillage direct seeding （CTDS） mode for four years, using the CTDS mode as the control. Compared with the CTDS mode, the actual rice yield of WDR decreased by 8.10% at the first year, whereas the plant height, spikelet number per panicle, spikelet fertility, 1000-grain weight, grain yield, actual yield, and harvest index increased with no-tillage years, which led to the actual yield increase by 6.49% at the fourth year. Correlation analysis showed that the panicle length was significantly related to the actual yield of WDR. Compared with the CTDS mode in terms of the soil properties, the pH value of the NTDS mode decreased every year, whereas the contents of soil organic matter and total N of the NTDS mode increased. In the 0-5 cm layer of the NTDS mode, the soil bulk decreased, whereas the contents of soil organic matter, total N, and available N increased. In the 5-20 cm layer of the NTDS mode, the available N and K decreased, whereas the soil bulk, contents of soil organic matter, and total N increased. In summary, the NTDS mode increased the rice yield, and could improve the paddy soil fertility of the top layer.展开更多
Construction of "water-saving landscape architecture" is a crucial content of building "conservation-minded society'',an important approach of ensuring the sustainable development of landscaping...Construction of "water-saving landscape architecture" is a crucial content of building "conservation-minded society'',an important approach of ensuring the sustainable development of landscaping industry.It targets at exploring a reasonable means of using the nature,so as to improve ecological conditions and environment,save resources and energies,and promote the harmonious coexistence of man and nature.Landscape plant is a significant component of landscape architecture,it is a key section to choose proper drought-resistant plant species for the landscape construction.展开更多
[Objective] This study aimed at exploring the utilization rate of water of the new water-saving rice variety ＂Luhan No.1＂ and providing references and basis for the further demonstration and extension.[Method] Water...[Objective] This study aimed at exploring the utilization rate of water of the new water-saving rice variety ＂Luhan No.1＂ and providing references and basis for the further demonstration and extension.[Method] Water-saving rice variety ＂Luhan No.1＂ and original receptor ＂6527＂ were used for dry processing without aquifer,and rice under regular irrigation conditions was used as the control.[Result] Under conditions which had economized on 67.4% of water compared with the regular irrigation,decreasing rates of 1 000-seed weight,seed setting rate,plant height and effective panicles of ＂Luhan No.1＂ were relatively small and had not achieved a significant level,while the decreasing rates of production of the region,total grains per panicle,theoretical production and filled grains per panicle of the original receptor ＂6527＂ were all over 25% and had attained very significant levels（P0.01）.[Conclusion] ＂Luhan No.1＂ had shown stable production,energy conservation,reducing environmental pollution and other advantages under water-conservating cultivation conditions.展开更多
Recent studies revealed that DNA methylation plays an important role in plant growth and development. In this study, a water-saving and drought-resistant rice variety Huhan 3 was subjected to drought stress from tille...Recent studies revealed that DNA methylation plays an important role in plant growth and development. In this study, a water-saving and drought-resistant rice variety Huhan 3 was subjected to drought stress from tillering to grain-filling stages in six successive growth cycles. The variations in DNA methylation pattern between the original generation （Go） and the sixth generation （G6） were analyzed by using methylation sensitive amplification polymorphism method. The results revealed that the methylated loci accounted for 34.3% to 34.8% of the total loci. Among these methylated loci, 83.1% to 84.8% were full- and hyper-methylated and 15.2% to 16.9% were hemi-methylated. The DNA methylation level decreased from the three-leaf to four-leaf stages in Huhan 3. Differentially methylated loci （DML） between generations or/and between different developmental stages accounted for 4.0% of the total loci, most of which were only related to plant development （57.9%）. Compared to Go, the DNA methylation pattern of G8 changed after drought domestication, at the three-leaf stage, de-methylation accounting for 59.1%, while at the four-leaf stage, re-methylation for 47.9%. Genome-wide alternations of DNA methylation were observed between the two seedling stages, and DML mainly occurred on the gene＇s promoter and exon region. The genes related to DML involved in a wide range of functional biology and participated in many important biological processes.展开更多
Compared to drought-susceptible rice cultivars(DSRs),drought-resistance rice cultivars(DRRs)could drastically reduce the amount of irrigation water input and simultaneously result in higher grain yield under water-sav...Compared to drought-susceptible rice cultivars(DSRs),drought-resistance rice cultivars(DRRs)could drastically reduce the amount of irrigation water input and simultaneously result in higher grain yield under water-saving irrigation conditions.However,the mechanisms underlying these properties are unclear.We investigated how improved agronomic traits contribute to higher yield and higher water use efficiency(WUE)in DRRs than in DSRs under alternate wetting and drying(AWD).Two DRRs and two DSRs were field-grown in 2015 and 2016 using two different irrigation regimes:continuous flooding(CF)and AWD.Under CF,no statistical differences in grain yield and WUE were observed between DRRs and DSRs.Irrigation water under the AWD regime was 275–349 mm,an amount 49.8%–56.2% of that(552–620 mm)applied under the CF regime.Compared to CF,AWD significantly decreased grain yield in both DRRs and DSRs,with a more significant reduction in DSRs,and WUE was increased in DRRs,but not in DSRs,by 9.9%–23.0% under AWD.Under AWD,DRRs showed a 20.2%–26.2% increase in grain yield and an 18.6%–24.5% increase in WUE compared to DSRs.Compared to DSRs,DRRs showed less redundant vegetative growth,greater sink capacity,higher grain filling efficiency,larger root biomass,and deeper root distribution under AWD.We conclude that these improved agronomic traits exert positive influences on WUE in DRRs under AWD.展开更多
The water shortage faced with rice production in China was comprehensively analyzed,and the seasonal as well as spatial and temporal differences were the factors limiting rice production,which would be a severe test f...The water shortage faced with rice production in China was comprehensively analyzed,and the seasonal as well as spatial and temporal differences were the factors limiting rice production,which would be a severe test for grain production safety.Therefore,solving strategies had been proposed from the following aspects：the improvement of irrigation practices was of significant effect on improving the high efficient utilization of water;the screening of drought resistance cultivars and upland rice cultivation could also greatly improve the ability of drought resistance;the combination of traditional breeding techniques with modern transgenic technology as well as the QTL analysis had made considerable progress on improving the soil moisture productive potential of rice from the perspective of genetics.The development of China＇s rice industry would face greater water scarcity in the future,but the conventional water-saving technologies could only reduce water consume to a certain extent,while the exploration and improvement of the water saving potential of wetland rice to give full play to the biological water-saving function would become the goal of agricultural development in China.展开更多
Water shortage is increasingly an important factor limiting the sustainable development of global economy, posing a hugethreat to social security and human existence. Water usage in agriculture accounts for about 70% ...Water shortage is increasingly an important factor limiting the sustainable development of global economy, posing a hugethreat to social security and human existence. Water usage in agriculture accounts for about 70% of total water consumptionin the world, and rice cultivation is in turn the largest water user, which accounts for about 50% of total water usage inagriculture. Therefore, it is quite important to improve water utilization efficiency to reduce water consumption in rice.Water stress causes severe inhibition of plant growth and development as well as yield reduction, however the extent ofinhibition or reduction varies greatly with the growth stages, duration and severity of stress, and plant genotypes. In rice,drought resistance and water utilization efficiency might be improved by developing stress resistant cultivars and conductingproper agronomic practices. It is hence imperative to determine the suitable criteria in morphological and physiologicaltraits for drought resistance and water utilization efficiency in conventional breeding of rice. At present, leaf rolling, leafwater potential and carbon isotope discrimination are commonly used criteria for the evaluation and identification ofgermplasm with high drought resistance or water utilization efficiency. With rapid development of molecular biology,marker-assisted selection has been used in rice breeding against water stress. In this review, therefore, the agronomicaspect of water saving techniques such as selection of suitable rice cultivars, planting pattern, mulching, deficit irrigationand alternative drying and moist irrigation are discussed and effective approaches are also recommended.展开更多
Two field experiments were conducted to study the effects of 6-year plastic film mulching on bacterial diversity, organic matter of paddy soil and water use efficiency on different soils with great environmental varia...Two field experiments were conducted to study the effects of 6-year plastic film mulching on bacterial diversity, organic matter of paddy soil and water use efficiency on different soils with great environmental variabilities in Zhejiang Province, China, under non-flooding condition. The experiment started in 2001 at two sites with one rice crop annually. Three treatments included plastic film mulching with no flooding (PM), no plastic film mulching and no flooding (UM), and traditional flooding management (TF). Soil samples were collected and analyzed for bacterial diversity by DGGE and organic matter content, and water use efficiency (WUE) was calculated. The results showed that PM treatment favored the development of a more total bacterial community compared with TF management, the total number of bands was 33.3, 31.7 at tiller stage and heading stage (p < 0.05*). Hence, organic matter content was decreased by 36.7% and 51.4% under PM at two sites. PM also produced similar rice grain yield as TF at Duntou site and Dingqiao site, the average was 7924 kg?ha?1 and 7015 kg?ha?1 for PM and 8150 kg?ha?1 and 6990 kg?ha?1 for TF, respectively. Compared to TF, WUE and irrigation water use efficiency were increased significantly by 70.2% - 80.4% and 273.7% - 1300.0% for PM. It is essential to develop the water-saving agriculture.展开更多
The present study investigated whether an irrigation system could be established to save water and increase grain yield to enhance water productivity by proper water management at the field level in irrigated lowland ...The present study investigated whether an irrigation system could be established to save water and increase grain yield to enhance water productivity by proper water management at the field level in irrigated lowland rice （Oryza sativa L.）. Using two field-grown rice cultivars, two irrigation systems; conventional irrigation and water-saving irrigation, were conducted. In the water-saving irrigation system, limiting values of soil water potential related to specific growth stages were proposed as irrigation indices. Compared with conventional irrigation where drainage was in mid-season and flooded at other times, the water-saving irrigation increased grain yield by 7.4% to 11.3%, reduced irrigation water by 24.5% to 29.2%, and increased water productivity （grain yield per cubic meter of irrigation water） by 43.1% to 50.3%. The water-saving irrigation significantly increased harvest index, improved milling and appearance qualities, elevated zeatin-I-zeaUn riboside concentrations in root bleedings and enhanced activities of sucrose synthase, adenosine diphosphate glucose pyrophosphorylase, starch synthase and starch branching enzyme in grains. Our results indicate that water-saving irrigation by controlling limiting values of soil water potential related to specific growth stages can enhance physiological activities of roots and grains, reduce water input, and increase grain yield.展开更多
Dissecting the mechanism of drought resistance(DR)and designing drought-resistant rice varieties are promising strategies to address the challenge of climate change.Here,we selected a typical droughtavoidant(DA)variet...Dissecting the mechanism of drought resistance(DR)and designing drought-resistant rice varieties are promising strategies to address the challenge of climate change.Here,we selected a typical droughtavoidant(DA)variety,IRAT109,and a drought-tolerant(DT)variety,Hanhui15,as parents to develop a stable recombinant inbred line(RIL)population(F8,1262 lines).The de novo assembled genomes of both parents were released.By resequencing of the RIL population,a set of 1189216 reliable SNPs were obtained and used to construct a dense genetic map.Using above-and belowground phenomic platforms and multimodal cameras,we captured 139040 image-based traits(i-traits)of whole-plant phenotypes in response to drought stress throughout the entire rice growth period and identified 32586 drought-responsive quantitative trait loci(QTLs),including 2097 unique QTLs.QTLs associated with panicle i-traits occurred more than 600 times on the middle of chromosome 8,and QTLs associated with leaf i-traits occurred more than 800 times on the 50 end of chromosome 3,indicating the potential effects of these QTLs on plant phenotypes.We selected three candidate genes(OsMADS50,OsGhd8,OsSAUR11)related to leaf,panicle,and root traits,respectively,and verified their functions in DR.OsMADS50 was found to negatively regulate DR by modulating leaf dehydration,grain size,and downward root growth.A total of 18 and 21 composite QTLs significantly related to grain weight and plant biomass were also screened from 597 lines in the RIL population under drought conditions in field experiments,and the composite QTL regions showed substantial overlap(76.9%)with known DR gene regions.Based on three candidate DR genes,we proposed a haplotype design suitable for different environments and breeding objectives.This study provides a valuable reference for multimodal and time-series phenomic analyses,deciphers the genetic mechanisms of DA and DT rice varieties,and offers a molecular navigation map for breeding of DR varieties.展开更多
Water shortage is increasingly limiting the luxury use of water in rice cultivation. In this study, non-flooded mulching cultivation of rice only consumed a fraction of the water that was needed for traditional floode...Water shortage is increasingly limiting the luxury use of water in rice cultivation. In this study, non-flooded mulching cultivation of rice only consumed a fraction of the water that was needed for traditional flooded cultivation and largely maintained the grain yield. We also investigated the growth and development of rice plants and examined grain yield formation when rice was subjected to non-flooded mulching cultivation. One indica hybrid rice combination was grown in a field experiment and three cultivation methods, traditional flooding （TF）, non-flooded straw mulching cultivation （SM） and non-flooded plastic mulching cultivation （PM）, were conducted during the whole season. Grain yield showed that there was no significant difference between SM and TF rice, but the grain yield of SM cultivation was significantly higher than that of PM. The tiller numbers were inhibited in the early stage under non-flooded mulching cultivation, but the situation was reversed at the later period. Both SM and PM rice reduced dry matter accumulation of shoot, but increased root dry weight, enhanced the remobilization of assimilates from stems to grains and increased the harvest index. During the middle and later grain filling period, mulched plants showed a faster decrease in chlorophyll concentrations, photosynthetic rates of flag leaves and root activity than TF rice, indicating that non-flooded mulching cultivation enhanced plant senescence. In comparison, SM treatment produced higher grain yield and, more dry matter accumulation and panicle numbers than the PM treatment. The overall results suggest that high yield of non-flooded mulching cultivation of rice can be achieved with much improved irrigaUonal water use efficiency.展开更多
Rice production accounts for approximately half of the freshwater resources utilized in agriculture,result-ing in greenhouse gas emissions such as methane(CH4)from flooded paddy fields.To address this chal-lenge,envir...Rice production accounts for approximately half of the freshwater resources utilized in agriculture,result-ing in greenhouse gas emissions such as methane(CH4)from flooded paddy fields.To address this chal-lenge,environmentally friendly and cost-effective water-saving techniques have become widely adopted in rice cultivation.However,the implementation of water-saving treatments(WsTs)in paddy-field rice has been associated with a substantial yield loss of up to 50%as well as a reduction in nitrogen use efficiency(NUE).In this study,we discovered that the target of rapamycin(TOR)signaling pathway is compromised in rice under WsT.Polysome profiling-coupled transcriptome sequencing(polysome-seq)analysis unveiled a substantial reduction in global translation in response to WST associated with the downregulation of TOR activity.Molecular,biochemical,and genetic analyses revealed new insights into the impact of the positive TOR-S6K-RPS6 and negative TOR-MAF1 modules on translation repression under WST.Intriguingly,ammonium exhibited a greater ability to alleviate growth constraints under WsT by enhancing TOR signaling,which simultaneously promoted uptake and utilization of ammonium and nitrogen allocation.We further demonstrated that TOR modulates the ammonium transporter AMT1;1 as well as the amino acid permease APP1 and dipeptide transporter NPF7.3 at the translational level through the 5'untranslated region.Collectively,these findings reveal that enhancing TOR signaling could mitigate rice yield penalty due to WST by regulating the processes involved in protein synthesis and NUE.Our study will contribute to the breeding of new rice varieties with increased water and fertilizer utilization efficiency.展开更多
文摘Water-saving and drought-resistance upland rice has become a preferable choice for cotton farmlands ready for changing crops or paddy fields with water in short,because simplified and mechanical cultivation can be applied for the rice varieties of drought resistance and high yield.At present,it has been applied with an area of 400 000 hm2 in Hunan Province and the area continues growing.The research bred and introduced the relevant cultivation technology standard applicable to local water-saving and drought-resistance rice varieties in order to improve farmer＇s benefits.
基金supported by the Key Project of Developing Agriculture through Science and Technology of Shanghai Municipal Agricultural Commission,China(Grant No.2010-1-1)Shanghai Science and Technology Development Funds,China(Grant No.11QA1405900)the National High-Tech Research and Development Program of China(Grant No.2012AA101102)
文摘To study the effects of long-term no-tillage direct seeding mode on rice yield and the soil physiochemical property in a rice-rapeseed rotation system, a comparative experiment with a water-saving and drought-resistance rice （WDR） variety and a double low rapeseed variety as materials was conducted under no-tillage direct seeding （NTDS） mode and conventional tillage direct seeding （CTDS） mode for four years, using the CTDS mode as the control. Compared with the CTDS mode, the actual rice yield of WDR decreased by 8.10% at the first year, whereas the plant height, spikelet number per panicle, spikelet fertility, 1000-grain weight, grain yield, actual yield, and harvest index increased with no-tillage years, which led to the actual yield increase by 6.49% at the fourth year. Correlation analysis showed that the panicle length was significantly related to the actual yield of WDR. Compared with the CTDS mode in terms of the soil properties, the pH value of the NTDS mode decreased every year, whereas the contents of soil organic matter and total N of the NTDS mode increased. In the 0-5 cm layer of the NTDS mode, the soil bulk decreased, whereas the contents of soil organic matter, total N, and available N increased. In the 5-20 cm layer of the NTDS mode, the available N and K decreased, whereas the soil bulk, contents of soil organic matter, and total N increased. In summary, the NTDS mode increased the rice yield, and could improve the paddy soil fertility of the top layer.
文摘Construction of "water-saving landscape architecture" is a crucial content of building "conservation-minded society'',an important approach of ensuring the sustainable development of landscaping industry.It targets at exploring a reasonable means of using the nature,so as to improve ecological conditions and environment,save resources and energies,and promote the harmonious coexistence of man and nature.Landscape plant is a significant component of landscape architecture,it is a key section to choose proper drought-resistant plant species for the landscape construction.
基金Supported by National863Green Super Rice Project"Water-saving and Drought-resistant Rice Germplasm Innovation"(2010AA101803)Anhui Province Foreign Expert Bureau Agricultural Introduction and Promotion Project"Demonstration and Extension of National Authorized Dry Rice Variety'Luhan No.1'"(Y20083400015)~~
文摘[Objective] This study aimed at exploring the utilization rate of water of the new water-saving rice variety ＂Luhan No.1＂ and providing references and basis for the further demonstration and extension.[Method] Water-saving rice variety ＂Luhan No.1＂ and original receptor ＂6527＂ were used for dry processing without aquifer,and rice under regular irrigation conditions was used as the control.[Result] Under conditions which had economized on 67.4% of water compared with the regular irrigation,decreasing rates of 1 000-seed weight,seed setting rate,plant height and effective panicles of ＂Luhan No.1＂ were relatively small and had not achieved a significant level,while the decreasing rates of production of the region,total grains per panicle,theoretical production and filled grains per panicle of the original receptor ＂6527＂ were all over 25% and had attained very significant levels（P0.01）.[Conclusion] ＂Luhan No.1＂ had shown stable production,energy conservation,reducing environmental pollution and other advantages under water-conservating cultivation conditions.
基金supported by the National High-Technology R&D Program of China (Grant No. 2012AA101102)the Project for High-Level Talents of China (Grant No. 2010C1120)Shanghai Key Program for Agriculture Science and Technology, China
文摘Recent studies revealed that DNA methylation plays an important role in plant growth and development. In this study, a water-saving and drought-resistant rice variety Huhan 3 was subjected to drought stress from tillering to grain-filling stages in six successive growth cycles. The variations in DNA methylation pattern between the original generation （Go） and the sixth generation （G6） were analyzed by using methylation sensitive amplification polymorphism method. The results revealed that the methylated loci accounted for 34.3% to 34.8% of the total loci. Among these methylated loci, 83.1% to 84.8% were full- and hyper-methylated and 15.2% to 16.9% were hemi-methylated. The DNA methylation level decreased from the three-leaf to four-leaf stages in Huhan 3. Differentially methylated loci （DML） between generations or/and between different developmental stages accounted for 4.0% of the total loci, most of which were only related to plant development （57.9%）. Compared to Go, the DNA methylation pattern of G8 changed after drought domestication, at the three-leaf stage, de-methylation accounting for 59.1%, while at the four-leaf stage, re-methylation for 47.9%. Genome-wide alternations of DNA methylation were observed between the two seedling stages, and DML mainly occurred on the gene＇s promoter and exon region. The genes related to DML involved in a wide range of functional biology and participated in many important biological processes.
基金the National Key Research and Development Program of China (2016YFD0300507,2016YFD0300108)the National Natural Science Foundation of China (31671630,31671638,31501264)the China Agriculture Research System (CARS-01)
文摘Compared to drought-susceptible rice cultivars(DSRs),drought-resistance rice cultivars(DRRs)could drastically reduce the amount of irrigation water input and simultaneously result in higher grain yield under water-saving irrigation conditions.However,the mechanisms underlying these properties are unclear.We investigated how improved agronomic traits contribute to higher yield and higher water use efficiency(WUE)in DRRs than in DSRs under alternate wetting and drying(AWD).Two DRRs and two DSRs were field-grown in 2015 and 2016 using two different irrigation regimes:continuous flooding(CF)and AWD.Under CF,no statistical differences in grain yield and WUE were observed between DRRs and DSRs.Irrigation water under the AWD regime was 275–349 mm,an amount 49.8%–56.2% of that(552–620 mm)applied under the CF regime.Compared to CF,AWD significantly decreased grain yield in both DRRs and DSRs,with a more significant reduction in DSRs,and WUE was increased in DRRs,but not in DSRs,by 9.9%–23.0% under AWD.Under AWD,DRRs showed a 20.2%–26.2% increase in grain yield and an 18.6%–24.5% increase in WUE compared to DSRs.Compared to DSRs,DRRs showed less redundant vegetative growth,greater sink capacity,higher grain filling efficiency,larger root biomass,and deeper root distribution under AWD.We conclude that these improved agronomic traits exert positive influences on WUE in DRRs under AWD.
文摘The water shortage faced with rice production in China was comprehensively analyzed,and the seasonal as well as spatial and temporal differences were the factors limiting rice production,which would be a severe test for grain production safety.Therefore,solving strategies had been proposed from the following aspects：the improvement of irrigation practices was of significant effect on improving the high efficient utilization of water;the screening of drought resistance cultivars and upland rice cultivation could also greatly improve the ability of drought resistance;the combination of traditional breeding techniques with modern transgenic technology as well as the QTL analysis had made considerable progress on improving the soil moisture productive potential of rice from the perspective of genetics.The development of China＇s rice industry would face greater water scarcity in the future,but the conventional water-saving technologies could only reduce water consume to a certain extent,while the exploration and improvement of the water saving potential of wetland rice to give full play to the biological water-saving function would become the goal of agricultural development in China.
文摘Water shortage is increasingly an important factor limiting the sustainable development of global economy, posing a hugethreat to social security and human existence. Water usage in agriculture accounts for about 70% of total water consumptionin the world, and rice cultivation is in turn the largest water user, which accounts for about 50% of total water usage inagriculture. Therefore, it is quite important to improve water utilization efficiency to reduce water consumption in rice.Water stress causes severe inhibition of plant growth and development as well as yield reduction, however the extent ofinhibition or reduction varies greatly with the growth stages, duration and severity of stress, and plant genotypes. In rice,drought resistance and water utilization efficiency might be improved by developing stress resistant cultivars and conductingproper agronomic practices. It is hence imperative to determine the suitable criteria in morphological and physiologicaltraits for drought resistance and water utilization efficiency in conventional breeding of rice. At present, leaf rolling, leafwater potential and carbon isotope discrimination are commonly used criteria for the evaluation and identification ofgermplasm with high drought resistance or water utilization efficiency. With rapid development of molecular biology,marker-assisted selection has been used in rice breeding against water stress. In this review, therefore, the agronomicaspect of water saving techniques such as selection of suitable rice cultivars, planting pattern, mulching, deficit irrigationand alternative drying and moist irrigation are discussed and effective approaches are also recommended.
文摘Two field experiments were conducted to study the effects of 6-year plastic film mulching on bacterial diversity, organic matter of paddy soil and water use efficiency on different soils with great environmental variabilities in Zhejiang Province, China, under non-flooding condition. The experiment started in 2001 at two sites with one rice crop annually. Three treatments included plastic film mulching with no flooding (PM), no plastic film mulching and no flooding (UM), and traditional flooding management (TF). Soil samples were collected and analyzed for bacterial diversity by DGGE and organic matter content, and water use efficiency (WUE) was calculated. The results showed that PM treatment favored the development of a more total bacterial community compared with TF management, the total number of bands was 33.3, 31.7 at tiller stage and heading stage (p < 0.05*). Hence, organic matter content was decreased by 36.7% and 51.4% under PM at two sites. PM also produced similar rice grain yield as TF at Duntou site and Dingqiao site, the average was 7924 kg?ha?1 and 7015 kg?ha?1 for PM and 8150 kg?ha?1 and 6990 kg?ha?1 for TF, respectively. Compared to TF, WUE and irrigation water use efficiency were increased significantly by 70.2% - 80.4% and 273.7% - 1300.0% for PM. It is essential to develop the water-saving agriculture.
基金Supported by the National Natural Science Foundation of China(30671225)the State Key Project(2004-BA520A12-5)+1 种基金the Natural Science Foundation of Jiangsu Province(BK2006069)Hong Kong Research Grants Council(Project HKBU 2465/05M).
文摘The present study investigated whether an irrigation system could be established to save water and increase grain yield to enhance water productivity by proper water management at the field level in irrigated lowland rice （Oryza sativa L.）. Using two field-grown rice cultivars, two irrigation systems; conventional irrigation and water-saving irrigation, were conducted. In the water-saving irrigation system, limiting values of soil water potential related to specific growth stages were proposed as irrigation indices. Compared with conventional irrigation where drainage was in mid-season and flooded at other times, the water-saving irrigation increased grain yield by 7.4% to 11.3%, reduced irrigation water by 24.5% to 29.2%, and increased water productivity （grain yield per cubic meter of irrigation water） by 43.1% to 50.3%. The water-saving irrigation significantly increased harvest index, improved milling and appearance qualities, elevated zeatin-I-zeaUn riboside concentrations in root bleedings and enhanced activities of sucrose synthase, adenosine diphosphate glucose pyrophosphorylase, starch synthase and starch branching enzyme in grains. Our results indicate that water-saving irrigation by controlling limiting values of soil water potential related to specific growth stages can enhance physiological activities of roots and grains, reduce water input, and increase grain yield.
基金supported by the National Natural Science Foundation of China(32172098 and U21A20205)the Natural Science Foundation of Shanghai(23ZR1455900 and 22ZR1455200).
文摘Dissecting the mechanism of drought resistance(DR)and designing drought-resistant rice varieties are promising strategies to address the challenge of climate change.Here,we selected a typical droughtavoidant(DA)variety,IRAT109,and a drought-tolerant(DT)variety,Hanhui15,as parents to develop a stable recombinant inbred line(RIL)population(F8,1262 lines).The de novo assembled genomes of both parents were released.By resequencing of the RIL population,a set of 1189216 reliable SNPs were obtained and used to construct a dense genetic map.Using above-and belowground phenomic platforms and multimodal cameras,we captured 139040 image-based traits(i-traits)of whole-plant phenotypes in response to drought stress throughout the entire rice growth period and identified 32586 drought-responsive quantitative trait loci(QTLs),including 2097 unique QTLs.QTLs associated with panicle i-traits occurred more than 600 times on the middle of chromosome 8,and QTLs associated with leaf i-traits occurred more than 800 times on the 50 end of chromosome 3,indicating the potential effects of these QTLs on plant phenotypes.We selected three candidate genes(OsMADS50,OsGhd8,OsSAUR11)related to leaf,panicle,and root traits,respectively,and verified their functions in DR.OsMADS50 was found to negatively regulate DR by modulating leaf dehydration,grain size,and downward root growth.A total of 18 and 21 composite QTLs significantly related to grain weight and plant biomass were also screened from 597 lines in the RIL population under drought conditions in field experiments,and the composite QTL regions showed substantial overlap(76.9%)with known DR gene regions.Based on three candidate DR genes,we proposed a haplotype design suitable for different environments and breeding objectives.This study provides a valuable reference for multimodal and time-series phenomic analyses,deciphers the genetic mechanisms of DA and DT rice varieties,and offers a molecular navigation map for breeding of DR varieties.
基金Supported by the National Natural Science Foundation of China （30671225）；the Natural Science Foundation of Jiangsu Province （BK2006069）；Hong Kong Research Grants Council （HKBU 2465/05M）；the Federal Ministry for Economic Cooperation and Development, Germany （BMZ） through a project with the International Rice Research Institute （IRRI）.
文摘Water shortage is increasingly limiting the luxury use of water in rice cultivation. In this study, non-flooded mulching cultivation of rice only consumed a fraction of the water that was needed for traditional flooded cultivation and largely maintained the grain yield. We also investigated the growth and development of rice plants and examined grain yield formation when rice was subjected to non-flooded mulching cultivation. One indica hybrid rice combination was grown in a field experiment and three cultivation methods, traditional flooding （TF）, non-flooded straw mulching cultivation （SM） and non-flooded plastic mulching cultivation （PM）, were conducted during the whole season. Grain yield showed that there was no significant difference between SM and TF rice, but the grain yield of SM cultivation was significantly higher than that of PM. The tiller numbers were inhibited in the early stage under non-flooded mulching cultivation, but the situation was reversed at the later period. Both SM and PM rice reduced dry matter accumulation of shoot, but increased root dry weight, enhanced the remobilization of assimilates from stems to grains and increased the harvest index. During the middle and later grain filling period, mulched plants showed a faster decrease in chlorophyll concentrations, photosynthetic rates of flag leaves and root activity than TF rice, indicating that non-flooded mulching cultivation enhanced plant senescence. In comparison, SM treatment produced higher grain yield and, more dry matter accumulation and panicle numbers than the PM treatment. The overall results suggest that high yield of non-flooded mulching cultivation of rice can be achieved with much improved irrigaUonal water use efficiency.
基金Thise research was supported by the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City City(320LH031 and HSPHDSRF-2023-04-016)Zhejiang Provincial Natural Science Foundation of China(LY21C020003)+3 种基金Zhejiang University Global Partnership Fund,Fundamental Research Funds for the Central Universities for the Central Universities(K20200168)the Key Research and Development Program of Zhejiang(2020C02002)National Natural Science Foundation of China(32201819)China Postdoctoral Science Foundation(2022M712807).
文摘Rice production accounts for approximately half of the freshwater resources utilized in agriculture,result-ing in greenhouse gas emissions such as methane(CH4)from flooded paddy fields.To address this chal-lenge,environmentally friendly and cost-effective water-saving techniques have become widely adopted in rice cultivation.However,the implementation of water-saving treatments(WsTs)in paddy-field rice has been associated with a substantial yield loss of up to 50%as well as a reduction in nitrogen use efficiency(NUE).In this study,we discovered that the target of rapamycin(TOR)signaling pathway is compromised in rice under WsT.Polysome profiling-coupled transcriptome sequencing(polysome-seq)analysis unveiled a substantial reduction in global translation in response to WST associated with the downregulation of TOR activity.Molecular,biochemical,and genetic analyses revealed new insights into the impact of the positive TOR-S6K-RPS6 and negative TOR-MAF1 modules on translation repression under WST.Intriguingly,ammonium exhibited a greater ability to alleviate growth constraints under WsT by enhancing TOR signaling,which simultaneously promoted uptake and utilization of ammonium and nitrogen allocation.We further demonstrated that TOR modulates the ammonium transporter AMT1;1 as well as the amino acid permease APP1 and dipeptide transporter NPF7.3 at the translational level through the 5'untranslated region.Collectively,these findings reveal that enhancing TOR signaling could mitigate rice yield penalty due to WST by regulating the processes involved in protein synthesis and NUE.Our study will contribute to the breeding of new rice varieties with increased water and fertilizer utilization efficiency.
