[Objective] The study aimed at investigating the effects of different geographic sites,soil chemical characteristics and nitrogen application levels on nitrogen accumulation and distribution in different organs and ut...[Objective] The study aimed at investigating the effects of different geographic sites,soil chemical characteristics and nitrogen application levels on nitrogen accumulation and distribution in different organs and utilization efficiency for mid-season hybrid rice.[Method] By using mid-season rice varieties II-you 7 and Yuxiangyou203 as the experimental materials,field experiment was conducted at seven ecological sites in four provinces or cities in Southwestern China in 2009.A total of four nitrogen application levels were set as follows：by using 75 kg/hm2 of P2O5 and 75 kg/hm2 of K2O as the base fertilizer,extra 0,90,150 and 210 kg/hm2 of nitrogen fertilizer（in which,base fertilizer,base-tillering fertilizer and base-earing fertilizer respectively accounted for 60%,20% and 20%.） was applied,respectively.In the split-plot design,fertilizer was considered as the main factor while rice variety was taken as the secondary factor.A total of eight treatments were set with three replications.[Result] Highly significant differences of grain yield were found among seven locations,two varieties,four nitrogen application levels,interactions of site × variety and site × nitrogen application level,but the interaction of variety ×nitrogen application level had no significant influence on rice yield.There were highly significant effects of site,varieties and nitrogen application level on dry matter production,nitrogen content,nitrogen utilization efficiency.Highly significant negative correlations between uptake efficiency and utilization efficiency for nitrogen were found;and multiple stepwise regression analysis showed that nitrogen uptake-utilization efficiency were significantly influenced by different ecological sites,chemical quality of soil and the levels of nitrogen application.[Conclusion] The research will provide theoretical and practical basis for the highly efficient application of nitrogen in mid-season hybrid rice cultivation.展开更多
[Objective] The aim was to research relationship between SPAD decline index after full-heading stage （SDIFHS） and productivity of rice. fertilized with nitro- gen in order to provide theoretical and practical refere...[Objective] The aim was to research relationship between SPAD decline index after full-heading stage （SDIFHS） and productivity of rice. fertilized with nitro- gen in order to provide theoretical and practical references for selection and breed- ing of rice varieties. [Method] From 2008 to 2010, 18 mid-season hybrid rice vari- eties were researched every year to explore relationship＇ between SDIFHS and pro- ductivity of rice fertilized with nitrogen. [Result] The productivity of rice fertilized with nitrogen was of extremely significant positive corretation with SDIFHS, because the higher SPAD decline index is, the higher LAI decline index and the transformation ratio of dry matter to spikes in overground plant would be. [Conclusion] The re- search established a new method to predict productivity of rice fertilized with nitro- gen based on SPAD decline index.展开更多
[Objective] The aim was to study the relationship of plant characters with bud living rate and mother stem emergence rate of ratoon rice before harvest. [Method] Eighteen mid-season hybrid rice cultivators approved re...[Objective] The aim was to study the relationship of plant characters with bud living rate and mother stem emergence rate of ratoon rice before harvest. [Method] Eighteen mid-season hybrid rice cultivators approved recently were taken as materials and relationship of plant characters including bud living rate and moth- er stem emergence rate of ratoon rice before harvest was explored, based on relat- ed data. [Result] The shorter rice with lower harvesting index is the main character of high emergence rate for first cropping rice; decline of plant height and increase of ear-bearing percentage would improve emergence of regenerative seedlings. [Conclusion] The research provided scientific reference for breeding of rice cultivars with high regenerative capacity.展开更多
Nitrogen is one of the important factors for high yield of rice.Apart from high yield,high quality has become the current urgent demand for rice production.Grain-filling stage is crucial for rice yield and quality for...Nitrogen is one of the important factors for high yield of rice.Apart from high yield,high quality has become the current urgent demand for rice production.Grain-filling stage is crucial for rice yield and quality formation.However,the effect of nitrogen on grain-filling characteristics and the relationship of grain-filling characteristics and rice quality of mid-season indica rice were still unclear.A field experiment was carried out to ascertain the critical grain-filling characteristics that contribute to rice milling quality,appearance quality and cooking and eating quality under nitrogen applications.The results showed that nitrogen applications prolonged the duration of superior and inferior grain filling.The mean grainfilling rate(G_(mean))and the maximum grain-filling rate(G_(max))of the inferior grains were positively correlated with chalky kernel rate,chalkiness,and amylose content.The time reaching the maximum grain-filling rate(T_(max)G)of the inferior grains was positively correlated with brown rice rate,milled rice rate,and head milled rice rate.Chalky kernel rate and chalkiness were negatively correlated with peak paste viscosity and breakdown viscosity.Less amylose content and more crude protein content were detected in nitrogen application of Liangyoupei 9 and Y Liangyou 2 both in 2016 and 2017.According to the correlation analysis,better cooking and eating quality of Y Liangyou 2 which had less amylose content might result from its higher G_(max)and G_(mean)of inferior grain than that of Liangyoupei 9 in the treatments of nitrogen application.These results indicated that the prolonging grain-filling duration and increasing grain weight at the maximum grain-filling rate of inferior grains contributed to the improvement of milling quality,appearance quality,and cooking and eating quality of mid-season indica rice under appropriate nitrogen applications.展开更多
Research on root morphological traits of dry-raised seedlings (D-RS) at different growth stages of rice have so far attracted less attention. In this study, using mid-season indica hy-
Dear Editor,Roots,as a major organ of plants,are involved in nutrient and water acquisition,and might play a vital role in yield increase and efficient N absorption with genetic improvement.Because of the great differ...Dear Editor,Roots,as a major organ of plants,are involved in nutrient and water acquisition,and might play a vital role in yield increase and efficient N absorption with genetic improvement.Because of the great differences in growth period and pattern between the old and new rice cultivars,it is difficult to clarify how genetic improvements contribute to root growth in rice.展开更多
基金Supported by Construction of Southwestern Rice Innovation System,Science and Technology Project on Food Production (2006BAD02-A05)Agriculture Science Technology Achievement TransformationFund (2006GB2F000256)+2 种基金Sichuan Provincial Foundation for Lead-ers of Disciplines in ScienceProject of Rice Breeding Technology ofSichuanProgram Promoted by Sichuan Financial Administration~~
文摘[Objective] The study aimed at investigating the effects of different geographic sites,soil chemical characteristics and nitrogen application levels on nitrogen accumulation and distribution in different organs and utilization efficiency for mid-season hybrid rice.[Method] By using mid-season rice varieties II-you 7 and Yuxiangyou203 as the experimental materials,field experiment was conducted at seven ecological sites in four provinces or cities in Southwestern China in 2009.A total of four nitrogen application levels were set as follows：by using 75 kg/hm2 of P2O5 and 75 kg/hm2 of K2O as the base fertilizer,extra 0,90,150 and 210 kg/hm2 of nitrogen fertilizer（in which,base fertilizer,base-tillering fertilizer and base-earing fertilizer respectively accounted for 60%,20% and 20%.） was applied,respectively.In the split-plot design,fertilizer was considered as the main factor while rice variety was taken as the secondary factor.A total of eight treatments were set with three replications.[Result] Highly significant differences of grain yield were found among seven locations,two varieties,four nitrogen application levels,interactions of site × variety and site × nitrogen application level,but the interaction of variety ×nitrogen application level had no significant influence on rice yield.There were highly significant effects of site,varieties and nitrogen application level on dry matter production,nitrogen content,nitrogen utilization efficiency.Highly significant negative correlations between uptake efficiency and utilization efficiency for nitrogen were found;and multiple stepwise regression analysis showed that nitrogen uptake-utilization efficiency were significantly influenced by different ecological sites,chemical quality of soil and the levels of nitrogen application.[Conclusion] The research will provide theoretical and practical basis for the highly efficient application of nitrogen in mid-season hybrid rice cultivation.
基金Supported by Southuest China Rice Innovation System and Crop High-yielding Project by Science and Technology (2011BAD02A05) Transformation Project of Agricultural Fruits into Capitals (2006GB2F000256)+2 种基金Sichuan Academic Leaders Training FundSichuan Rice Cultivation Key ProjectSichuan Financial Distribution Project~~
文摘[Objective] The aim was to research relationship between SPAD decline index after full-heading stage （SDIFHS） and productivity of rice. fertilized with nitro- gen in order to provide theoretical and practical references for selection and breed- ing of rice varieties. [Method] From 2008 to 2010, 18 mid-season hybrid rice vari- eties were researched every year to explore relationship＇ between SDIFHS and pro- ductivity of rice fertilized with nitrogen. [Result] The productivity of rice fertilized with nitrogen was of extremely significant positive corretation with SDIFHS, because the higher SPAD decline index is, the higher LAI decline index and the transformation ratio of dry matter to spikes in overground plant would be. [Conclusion] The re- search established a new method to predict productivity of rice fertilized with nitro- gen based on SPAD decline index.
基金Supported by Sichuan Financial and Engineering Foundation for the Young(2007QNJJ-020)Sichuan Cultivation Foundation for Academy leaders+3 种基金Sichuan Key Project of Rice BreedingConstruction of Rice Industry System in SouthwestNational Crop-harvesting ProjectSichuan Financial Promotion~~
文摘[Objective] The aim was to study the relationship of plant characters with bud living rate and mother stem emergence rate of ratoon rice before harvest. [Method] Eighteen mid-season hybrid rice cultivators approved recently were taken as materials and relationship of plant characters including bud living rate and moth- er stem emergence rate of ratoon rice before harvest was explored, based on relat- ed data. [Result] The shorter rice with lower harvesting index is the main character of high emergence rate for first cropping rice; decline of plant height and increase of ear-bearing percentage would improve emergence of regenerative seedlings. [Conclusion] The research provided scientific reference for breeding of rice cultivars with high regenerative capacity.
基金the National Key R&D Program of China(2016YFD0300505)the Rice Industry Technology System of Henan Province,China(S201204-G02)。
文摘Nitrogen is one of the important factors for high yield of rice.Apart from high yield,high quality has become the current urgent demand for rice production.Grain-filling stage is crucial for rice yield and quality formation.However,the effect of nitrogen on grain-filling characteristics and the relationship of grain-filling characteristics and rice quality of mid-season indica rice were still unclear.A field experiment was carried out to ascertain the critical grain-filling characteristics that contribute to rice milling quality,appearance quality and cooking and eating quality under nitrogen applications.The results showed that nitrogen applications prolonged the duration of superior and inferior grain filling.The mean grainfilling rate(G_(mean))and the maximum grain-filling rate(G_(max))of the inferior grains were positively correlated with chalky kernel rate,chalkiness,and amylose content.The time reaching the maximum grain-filling rate(T_(max)G)of the inferior grains was positively correlated with brown rice rate,milled rice rate,and head milled rice rate.Chalky kernel rate and chalkiness were negatively correlated with peak paste viscosity and breakdown viscosity.Less amylose content and more crude protein content were detected in nitrogen application of Liangyoupei 9 and Y Liangyou 2 both in 2016 and 2017.According to the correlation analysis,better cooking and eating quality of Y Liangyou 2 which had less amylose content might result from its higher G_(max)and G_(mean)of inferior grain than that of Liangyoupei 9 in the treatments of nitrogen application.These results indicated that the prolonging grain-filling duration and increasing grain weight at the maximum grain-filling rate of inferior grains contributed to the improvement of milling quality,appearance quality,and cooking and eating quality of mid-season indica rice under appropriate nitrogen applications.
文摘Research on root morphological traits of dry-raised seedlings (D-RS) at different growth stages of rice have so far attracted less attention. In this study, using mid-season indica hy-
基金supported by the Zhejiang Provincial Natural Science Foundation (LY16C130006)the Basic Research Foundation of National Commonweal Research Institute (2014RG004-3)the National Natural Science Foundation (31501272)
文摘Dear Editor,Roots,as a major organ of plants,are involved in nutrient and water acquisition,and might play a vital role in yield increase and efficient N absorption with genetic improvement.Because of the great differences in growth period and pattern between the old and new rice cultivars,it is difficult to clarify how genetic improvements contribute to root growth in rice.
基金the National Natural Science Foundation of China[grant numbers 41931181 and 42075048]the Youth Innovation Promotion Association of the Chinese Academy of Sciences[grant number 2022075].
