Light deficiency is a growing abiotic stress in rice production.However,few studies focus on shading effects on grain yield and quality of rice in East China.It is also essential to investigate proper nitrogen(N)appli...Light deficiency is a growing abiotic stress in rice production.However,few studies focus on shading effects on grain yield and quality of rice in East China.It is also essential to investigate proper nitrogen(N)application strategies that can effectively alleviate the negative impacts of light deficiency on grain yield and quality in rice.A two-year field experiment was conducted to explore the effects of shading(non-shading and shading from heading to maturity)and panicle N application(NDP,decreased panicle N rate;NMP,medium panicle N rate;NIP,increased panicle N rate)treatments on rice yield-and quality-related characteristics.Compared with non-shading,shading resulted in a 9.5-14.8%yield loss(P<0.05),mainly due to lower filled-grain percentage and grain weight.NMP and NIP had higher(P<0.05)grain yield than NDP under non-shading,and no significant difference was observed in rice grain yield among NDP,NMP,and NIP under shading.Compared with NMP and NIP,NDP achieved less yield loss under shading because of the increased filled-grain percentage and grain weight.Shading reduced leaf photosynthetic rate after heading,as well as shoot biomass weight at maturity,shoot biomass accumulation from heading to maturity,and nonstructural carbohydrate(NSC)content in the stem at maturity(P<0.05).The harvest index and NSC remobilization reserve of NDP were increased under shading.Shading decreased(P<0.05)percentages of brown rice,milled rice,head rice,and amylose content while increasing(P<0.05)chalky rice percentage,chalky area,chalky degree,and grain protein.NMP demonstrated a better milling quality under non-shading,while NDP demonstrated under shading.NDP exhibited both lower chalky rice percentage,chalky area,and chalky degree under non-shading and shading,compared with NMP and NIP.NDP under shading decreased amylose content and breakdown but increased grain protein content and setback,contributing to similar overall palatability to non-shading.Our results suggested severe grain yield and quality penalty of rice when subjected to shading after heading.NDP improved NSC remobilization,harvest index,and sink-filling efficiency and alleviated yield loss under shading.Besides,NDP would maintain rice’s milling,appearance,and cooking and eating qualities under shading.Proper N management with a decreased panicle N rate could be adopted to mitigate the negative effects of shading on rice grain yield and quality.展开更多
The yield potential of japonica/indica hybrids(JIH)has been achieved over 13.5 t ha–1 in large-scale rice fields,and some physiological traits for yield advantage of JIH over japonica inbred rice(JI)and indica hybrid...The yield potential of japonica/indica hybrids(JIH)has been achieved over 13.5 t ha–1 in large-scale rice fields,and some physiological traits for yield advantage of JIH over japonica inbred rice(JI)and indica hybrid rice(IH)were also identified.To date,little attention has been paid to morphological traits for yield advantage of JIH over JI and IH.For this reason,three JIH,three JI,and three IH were field-grown at East China(Ningbo,Zhejiang Province)in 2015 and 2016.Compared with JI and IH,JIH had 14.3 and 20.8%higher grain yield,respectively,attributed to its more spikelets per panicle and relatively high percentage of filled grains.The advantage in spikelets per panicle of JIH over JI and IH was shown in number of grains on the upper,middle,and lower branches.Compared with JI and IH,JIH had higher leaf area through leaf width and lower leaf angle of upper three leaves,higher leaf area index and leaf area per tiller at heading and maturity stages,higher stem weight per tiller and K and Si concentrations of stem at maturity,higher dry matter weight in leaf,stem,and panicle at heading and maturity stages,and higher biomass accumulation after heading and lower biomass translocation from stem during ripening.Leaf width of upper three leaves were correlated positively,while leaf angle of upper three leaves were correlated negatively with biomass accumulation after heading,stem weight per tiller,and per unit length.Our results indicated that the grain yield advantage of JIH was ascribed mainly to the more spikelets per panicle and relatively high percentage of filled grains.Higher leaf area through leaf width and more erect leaves were associated with improved biomass accumulation and stem weighing during ripening,and were the primary morphological traits underlying higher grain yield of JIH.展开更多
基金This work was financed by the National Natural Science Foundation of China(U20A2022,31901448 and 32001466)the Postdoctoral Research Foundation of China(2020M671628 and 2020M671629)+2 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions,China(19KJB210004)the Key Research and Development Program of Jiangsu Province,China(BE2019343)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China.
文摘Light deficiency is a growing abiotic stress in rice production.However,few studies focus on shading effects on grain yield and quality of rice in East China.It is also essential to investigate proper nitrogen(N)application strategies that can effectively alleviate the negative impacts of light deficiency on grain yield and quality in rice.A two-year field experiment was conducted to explore the effects of shading(non-shading and shading from heading to maturity)and panicle N application(NDP,decreased panicle N rate;NMP,medium panicle N rate;NIP,increased panicle N rate)treatments on rice yield-and quality-related characteristics.Compared with non-shading,shading resulted in a 9.5-14.8%yield loss(P<0.05),mainly due to lower filled-grain percentage and grain weight.NMP and NIP had higher(P<0.05)grain yield than NDP under non-shading,and no significant difference was observed in rice grain yield among NDP,NMP,and NIP under shading.Compared with NMP and NIP,NDP achieved less yield loss under shading because of the increased filled-grain percentage and grain weight.Shading reduced leaf photosynthetic rate after heading,as well as shoot biomass weight at maturity,shoot biomass accumulation from heading to maturity,and nonstructural carbohydrate(NSC)content in the stem at maturity(P<0.05).The harvest index and NSC remobilization reserve of NDP were increased under shading.Shading decreased(P<0.05)percentages of brown rice,milled rice,head rice,and amylose content while increasing(P<0.05)chalky rice percentage,chalky area,chalky degree,and grain protein.NMP demonstrated a better milling quality under non-shading,while NDP demonstrated under shading.NDP exhibited both lower chalky rice percentage,chalky area,and chalky degree under non-shading and shading,compared with NMP and NIP.NDP under shading decreased amylose content and breakdown but increased grain protein content and setback,contributing to similar overall palatability to non-shading.Our results suggested severe grain yield and quality penalty of rice when subjected to shading after heading.NDP improved NSC remobilization,harvest index,and sink-filling efficiency and alleviated yield loss under shading.Besides,NDP would maintain rice’s milling,appearance,and cooking and eating qualities under shading.Proper N management with a decreased panicle N rate could be adopted to mitigate the negative effects of shading on rice grain yield and quality.
基金financed by the National Key Research and Development Program of China (2018YFD0300802)the Key Research and Development Program of Jiangsu Province, China (BE2016351)the Priority Academic Program Development of Jiangsu Higher Education Institutions, China (PAPD)
文摘The yield potential of japonica/indica hybrids(JIH)has been achieved over 13.5 t ha–1 in large-scale rice fields,and some physiological traits for yield advantage of JIH over japonica inbred rice(JI)and indica hybrid rice(IH)were also identified.To date,little attention has been paid to morphological traits for yield advantage of JIH over JI and IH.For this reason,three JIH,three JI,and three IH were field-grown at East China(Ningbo,Zhejiang Province)in 2015 and 2016.Compared with JI and IH,JIH had 14.3 and 20.8%higher grain yield,respectively,attributed to its more spikelets per panicle and relatively high percentage of filled grains.The advantage in spikelets per panicle of JIH over JI and IH was shown in number of grains on the upper,middle,and lower branches.Compared with JI and IH,JIH had higher leaf area through leaf width and lower leaf angle of upper three leaves,higher leaf area index and leaf area per tiller at heading and maturity stages,higher stem weight per tiller and K and Si concentrations of stem at maturity,higher dry matter weight in leaf,stem,and panicle at heading and maturity stages,and higher biomass accumulation after heading and lower biomass translocation from stem during ripening.Leaf width of upper three leaves were correlated positively,while leaf angle of upper three leaves were correlated negatively with biomass accumulation after heading,stem weight per tiller,and per unit length.Our results indicated that the grain yield advantage of JIH was ascribed mainly to the more spikelets per panicle and relatively high percentage of filled grains.Higher leaf area through leaf width and more erect leaves were associated with improved biomass accumulation and stem weighing during ripening,and were the primary morphological traits underlying higher grain yield of JIH.
