Employing the pot experiment of the complete random block design with 6 replications,four varieties of japonica rice (Fujisaka 5,Honenwase,Akitakomachi and Taichung 65) were used to study the varietal differences in l...Employing the pot experiment of the complete random block design with 6 replications,four varieties of japonica rice (Fujisaka 5,Honenwase,Akitakomachi and Taichung 65) were used to study the varietal differences in leaf nitrogen content(LNC) and leaf area during mature period,their relation and effects to the ripening rate.The results showed that(1) thee were varietal differences in LNC at the heading stage and the LNC decrease rate during the matue period,the high LNC at the heading stage was related to the rapid LNC decrease.(2) There were two phases of the leaf area changing process during the mature period,first was the stable,and second was the decreased phase.There was varietal difference in the critical time of phase 1 and phase 2.The hign leaf area in the phase 1 was in relation to the rapid leaf area decrease in the phase 2.It was not found that there was relation between the leaf quality and quantity.(3)It wa unfavorable to the ripening rate for the high leaf area at the heading stage and the rapid decrease of the leaf area during the mature period.(4)It was put forward that the super high yield rice variety should possess the not very high leaf area and high LNC at the heading stage,slow senescence in the leaf area during the mature period.展开更多
Increasing leaf photosynthesis per area（A） is of great importance to achieve yield further improvement. The aim of this study was to exploit varietal difference in A and its correlation with specific leaf weight（SL...Increasing leaf photosynthesis per area（A） is of great importance to achieve yield further improvement. The aim of this study was to exploit varietal difference in A and its correlation with specific leaf weight（SLW）. Twelve rice cultivars, including 6 indica and 6 japonica varieties, were pot-grown under two N treatments, low N（LN） and sufficient N（SN）. Leaf photosynthesis and related parameters were measured at tillering stage. Compared with LN treatment, A, stomatal conductance（g_s）, mesophyll conductance（g_m）, leaf N content（N_（area））, and chlorophyll content were significantly improved under SN treatment, while SLW and photosynthetic N use efficiency（PNUE） were generally decreased. Varietal difference in A was positively related to both g_s and g_m, but not related to N_（area）. This resulted in a low PNUE in high N_（area） leaves. Varietal difference in PNUE was generally negatively related to SLW. Response of PNUE to N supply varied among different rice cultivars, and interestingly, the decrease in PNUE under SN was negatively related to the decrease in SLW. With a higher N_（area）, japonica rice cultivars did not show a higher A than indica rice cultivars because of possession of high-SLW leaves. Therefore, varietal difference in A was not related to N_（area）, and SLW can substantially interfere with the correlation between A and N_（area）. These findings may provide useful information for rice breeders to maximize A and PNUE, rather than over reliance on N_（area） as an indicator of photosynthetic performance.展开更多
The variation and correlation of leaf economics and vein traits are crucial for predicting plant ecological strategies under different environmental changes.However,correlations between these two suites of traits and ...The variation and correlation of leaf economics and vein traits are crucial for predicting plant ecological strategies under different environmental changes.However,correlations between these two suites of traits and abiotic factors such as soil water and nitrogen content remain ambiguous.We measured leaf economics and vein traits as well as soil water and nitrogen content for two different shade-tolerant species(Betula platyphylla and Acer mono)in four mixed broadleaved-Korean pine(Pinus koraiensis)forests along a latitudinal gradient in Northeast China.We found that leaf economics traits and vein traits were decoupled in shade-intolerant species,Betula platphylla,but significantly coupled in a shadetolerant species,A.mono.We found stronger correlations among leaf traits in the shade tolerant species than in the shade intolerant species.Furthermore,leaf economic traits were positively correlated with the soil water gradient for both species,whereas vein traits were positively correlated with soil water gradient for the shade intolerant species but negatively correlated in the shade tolerant species.Although economic traits were positively correlated with soil nitrogen gradient in shade intolerant species but not correlated in shade tolerant species,vein traits were negatively correlated with soil nitrogen gradient in shade tolerant species but not correlated in shade intolerant species.Our study provides evidence for distinct correlations between leaf economics and vein traits and local abiotic factors of species differing in light demands.We recommend that the ecological significance of shade tolerance be considered for species when evaluating ecosystem functions and predicting plant responses to environmental changes.展开更多
[Objective] The aim was to build spectral diagnosis model for nitrogen nutrition in rice leaf.[Method] Through determination of transmission,absorption spectra and nitrogen content on rice leaves of different rice var...[Objective] The aim was to build spectral diagnosis model for nitrogen nutrition in rice leaf.[Method] Through determination of transmission,absorption spectra and nitrogen content on rice leaves of different rice varieties（Xiangyou 109 and Shanyou 98）,different growth periods and different nitrogen levels,we analyzed the correlation between leaf spectra and their nitrogen contents,and built prediction model of spectral index for nitrogen content in rice leaf.[Result] The detection precision of this model was above 80% that can be used on diagnosing of rice nitrogen nutrition.[Conclusion] The study provided evidence for monitoring nitrogen nutrition status of rice.展开更多
Nitrogen fertilizer application is an important measure to obtain high and stable corn yield,and the moisture content of corn grains is an important factor affecting the quality of mechanical grain harvesting.In this ...Nitrogen fertilizer application is an important measure to obtain high and stable corn yield,and the moisture content of corn grains is an important factor affecting the quality of mechanical grain harvesting.In this study,four different nitrogen fertilizer treatments from 0 to 450 kg ha^(–1) pure nitrogen were set for a planting density of 12.0×10^(4) plants ha^(–1) in 2017 and 2018,and 18 different nitrogen fertilizer treatments from 0 to 765 kg ha^(–1) pure nitrogen were set for planting densities of 7.5×10^(4) and 12.0×10^(4) plants ha^(–1) in 2019,to investigate the effect of nitrogen application rate on the moisture content of corn grains.Under each treatment,the growth of corn,leaf area index(LAI)of green leaves,grain moisture content,and grain dehydration rate were measured.The results showed that,as nitrogen application increased from 0 to 765 kg ha^(–1),the silking stage was delayed by about 1 day,the maturity stage was delayed by about 1–2 days,and the number of physiologically mature green leaves and LAI increased.At and after physiological maturity,the extreme difference in grain moisture content between different nitrogen application rates was 1.9–4.0%.As the amount of nitrogen application increased,the corn grain dehydration rate after physiological maturity decreased,but it did not reach statistical significance between nitrogen application rate and grain dehydration rate.No significant correlation was observed between LAI at physiological maturity and grain dehydration rate after physiological maturity.In short,nitrogen application affected the grain moisture content of corn at and after physiological maturity,however,the difference in grain moisture content among different nitrogen application rates was small.These results suggest that the effect of nitrogen application on the moisture content of corn grains should not be considered in agricultural production.展开更多
The yield of maize(Zea mays L.)is highly influenced by nitrogen fertilization.This study investigated the impact of nitrogen fertilization on morphophysiological traits in maize(Zea mays L.)and developed algorithms to...The yield of maize(Zea mays L.)is highly influenced by nitrogen fertilization.This study investigated the impact of nitrogen fertilization on morphophysiological traits in maize(Zea mays L.)and developed algorithms to relate manual phenotyping and digital phenotyping of maize with leaf nitrogen and digital field image traits.The experiment included three hybrid maize varieties,V1(Hybrid 981),V2(BARI Hybrid maize-9),and V3(Hybrid P3396),which were evaluated across three nitrogen levels(N1=100 kg N ha^(−1),N2=200 kg N ha^(−1),N3=300 kg N ha^(−1))in a split-plot design with three replications.The results revealed that nitrogen levels(N),varieties(V),and their interactions(V×N)significantly influenced traits such as plant height(PH),leaf area index(LAI),normalized difference vegetation index(NDVI),canopy cover(CC),chlorophyll content(Chl a and Chl b),leaf nitrogen content(LNC),total dry matter(TDM),and grain yield.The hybrid P3396 with 300 kg N ha^(−1)(V3N3)achieved the highest grain yield of 14.45 t ha^(−1),which was statistically similar to that of Hybrid 981 and 300 kg N ha^(−1)(V1N3).Nitrogen significantly improved dry matter accumulation,leaf area,and physiological parameters,with maximum values recorded during flowering.The NDVI,CC,and SPAD were strongly correlated with LNC and TDM,highlighting their potential as indicators for nitrogen management.The digital imaging traits analysed via software effectively differentiated the nitrogen treatments,demonstrating their utility for precise nitrogen application.In conclusion,nitrogen fertilization at 300 kg N ha^(−1) optimized the growth and yield of hybrid maize,with Hybrid P3396 performing best.This study underscores the role of advanced phenotyping tools in improving nitrogen use efficiency and sustainable maize production.展开更多
Investigating the effects of ontogenetic stage and leaf age on leaf traits is important for understanding the utilization and distribution of resources in the process of plant growth.However,few studies have been cond...Investigating the effects of ontogenetic stage and leaf age on leaf traits is important for understanding the utilization and distribution of resources in the process of plant growth.However,few studies have been conducted to show how traits and trait-trait relationships change across a range of ontogenetic stage and leaf age for evergreen coniferous species.We divided 67 Pinus koraiensis Sieb.et Zucc.of various sizes(0.3-100 cm diameter at breast height,DBH)into four ontogenetic stages,i.e.,young trees,middle-aged trees,mature trees and over-mature trees,and measured the leaf mass per area(LMA),leaf dry matter content(LDMC),and mass-based leaf nitrogen content(N)and phosphorus content(P)of each leaf age group for each sampled tree.One-way analysis of variance(ANOVA)was used to describe the variation in leaf traits by ontogenetic stage and leaf age.The standardized major axis method was used to explore the effects of ontogenetic stage and leaf age on trait-trait relationships.We found that LMA and LDMC increased significantly and N and P decreased significantly with increases in the ontogenetic stage and leaf age.Most trait-trait relationships were consistent with the leaf economic spectrum(LES)at a global scale.Among them,leaf N content and LDMC showed a significant negative correlation,leaf N and P contents showed a significant positive correlation,and the absolute value of the slopes of the trait-trait relationships showed a gradually increasing trend with an increasing ontogenetic stage.LMA and LDMC showed a significant positive correlation,and the slopes of the trait-trait relationships showed a gradually decreasing trend with leaf age.Additionally,there were no significant relationships between leaf N content and LMA in most groups,which is contrary to the expectation of the LES.Overall,in the early ontogenetic stages and leaf ages,the leaf traits tend to be related to a"low investment-quick returns"resource strategy.In contrast,in the late ontogenetic stages and leaf ages,they tend to be related to a"high investment-slow returns"resource strategy.Our results reflect the optimal allocation of resources in Pinus koraiensis according to its functional needs during tree and leaf ontogeny.展开更多
文摘Employing the pot experiment of the complete random block design with 6 replications,four varieties of japonica rice (Fujisaka 5,Honenwase,Akitakomachi and Taichung 65) were used to study the varietal differences in leaf nitrogen content(LNC) and leaf area during mature period,their relation and effects to the ripening rate.The results showed that(1) thee were varietal differences in LNC at the heading stage and the LNC decrease rate during the matue period,the high LNC at the heading stage was related to the rapid LNC decrease.(2) There were two phases of the leaf area changing process during the mature period,first was the stable,and second was the decreased phase.There was varietal difference in the critical time of phase 1 and phase 2.The hign leaf area in the phase 1 was in relation to the rapid leaf area decrease in the phase 2.It was not found that there was relation between the leaf quality and quantity.(3)It wa unfavorable to the ripening rate for the high leaf area at the heading stage and the rapid decrease of the leaf area during the mature period.(4)It was put forward that the super high yield rice variety should possess the not very high leaf area and high LNC at the heading stage,slow senescence in the leaf area during the mature period.
基金supported by the National Natural Science Foundation of China(31301840)the National Excellent Doctoral Dissertation of China(201465)+2 种基金the Program for Changjiang Scholars and Innovative Research Team in University of China(IRT1247)the Natural Science Foundation of Hubei Province,China(2013CFB201)the Fundamental Research Funds for the Central Universities,China(2013PY107)
文摘Increasing leaf photosynthesis per area（A） is of great importance to achieve yield further improvement. The aim of this study was to exploit varietal difference in A and its correlation with specific leaf weight（SLW）. Twelve rice cultivars, including 6 indica and 6 japonica varieties, were pot-grown under two N treatments, low N（LN） and sufficient N（SN）. Leaf photosynthesis and related parameters were measured at tillering stage. Compared with LN treatment, A, stomatal conductance（g_s）, mesophyll conductance（g_m）, leaf N content（N_（area））, and chlorophyll content were significantly improved under SN treatment, while SLW and photosynthetic N use efficiency（PNUE） were generally decreased. Varietal difference in A was positively related to both g_s and g_m, but not related to N_（area）. This resulted in a low PNUE in high N_（area） leaves. Varietal difference in PNUE was generally negatively related to SLW. Response of PNUE to N supply varied among different rice cultivars, and interestingly, the decrease in PNUE under SN was negatively related to the decrease in SLW. With a higher N_（area）, japonica rice cultivars did not show a higher A than indica rice cultivars because of possession of high-SLW leaves. Therefore, varietal difference in A was not related to N_（area）, and SLW can substantially interfere with the correlation between A and N_（area）. These findings may provide useful information for rice breeders to maximize A and PNUE, rather than over reliance on N_（area） as an indicator of photosynthetic performance.
基金This work was supported by the National Key R&D Program of China(2022YFD2201100)the National Natural Science Foundation of China(31971636)the Fundamental Research Funds for the Central Universities(2572022DS13).
文摘The variation and correlation of leaf economics and vein traits are crucial for predicting plant ecological strategies under different environmental changes.However,correlations between these two suites of traits and abiotic factors such as soil water and nitrogen content remain ambiguous.We measured leaf economics and vein traits as well as soil water and nitrogen content for two different shade-tolerant species(Betula platyphylla and Acer mono)in four mixed broadleaved-Korean pine(Pinus koraiensis)forests along a latitudinal gradient in Northeast China.We found that leaf economics traits and vein traits were decoupled in shade-intolerant species,Betula platphylla,but significantly coupled in a shadetolerant species,A.mono.We found stronger correlations among leaf traits in the shade tolerant species than in the shade intolerant species.Furthermore,leaf economic traits were positively correlated with the soil water gradient for both species,whereas vein traits were positively correlated with soil water gradient for the shade intolerant species but negatively correlated in the shade tolerant species.Although economic traits were positively correlated with soil nitrogen gradient in shade intolerant species but not correlated in shade tolerant species,vein traits were negatively correlated with soil nitrogen gradient in shade tolerant species but not correlated in shade intolerant species.Our study provides evidence for distinct correlations between leaf economics and vein traits and local abiotic factors of species differing in light demands.We recommend that the ecological significance of shade tolerance be considered for species when evaluating ecosystem functions and predicting plant responses to environmental changes.
基金Supported by National Natural Science Foundation(10664001,41061039)National 863 Project(2007AA10Z205)+1 种基金Project for Excellent Young Scientists and Technicians of GuizhouNational Project for Innovative Experiments of College Students(Guizhou University200820)~~
文摘[Objective] The aim was to build spectral diagnosis model for nitrogen nutrition in rice leaf.[Method] Through determination of transmission,absorption spectra and nitrogen content on rice leaves of different rice varieties（Xiangyou 109 and Shanyou 98）,different growth periods and different nitrogen levels,we analyzed the correlation between leaf spectra and their nitrogen contents,and built prediction model of spectral index for nitrogen content in rice leaf.[Result] The detection precision of this model was above 80% that can be used on diagnosing of rice nitrogen nutrition.[Conclusion] The study provided evidence for monitoring nitrogen nutrition status of rice.
基金This study was supported by the National Key Research and Development Program of China(2016YFD0300605)the China Agriculture Research System of MOF and MARA(CARS-02-25)the Agricultural Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences.
文摘Nitrogen fertilizer application is an important measure to obtain high and stable corn yield,and the moisture content of corn grains is an important factor affecting the quality of mechanical grain harvesting.In this study,four different nitrogen fertilizer treatments from 0 to 450 kg ha^(–1) pure nitrogen were set for a planting density of 12.0×10^(4) plants ha^(–1) in 2017 and 2018,and 18 different nitrogen fertilizer treatments from 0 to 765 kg ha^(–1) pure nitrogen were set for planting densities of 7.5×10^(4) and 12.0×10^(4) plants ha^(–1) in 2019,to investigate the effect of nitrogen application rate on the moisture content of corn grains.Under each treatment,the growth of corn,leaf area index(LAI)of green leaves,grain moisture content,and grain dehydration rate were measured.The results showed that,as nitrogen application increased from 0 to 765 kg ha^(–1),the silking stage was delayed by about 1 day,the maturity stage was delayed by about 1–2 days,and the number of physiologically mature green leaves and LAI increased.At and after physiological maturity,the extreme difference in grain moisture content between different nitrogen application rates was 1.9–4.0%.As the amount of nitrogen application increased,the corn grain dehydration rate after physiological maturity decreased,but it did not reach statistical significance between nitrogen application rate and grain dehydration rate.No significant correlation was observed between LAI at physiological maturity and grain dehydration rate after physiological maturity.In short,nitrogen application affected the grain moisture content of corn at and after physiological maturity,however,the difference in grain moisture content among different nitrogen application rates was small.These results suggest that the effect of nitrogen application on the moisture content of corn grains should not be considered in agricultural production.
基金supported by the Bangladesh Agricultural Research Insti-tute,Gazipur-1701,Bangladesh.This research was also funded by Taif University,Saudi Arabia,Project No.(TU-DSPP-2024-07).
文摘The yield of maize(Zea mays L.)is highly influenced by nitrogen fertilization.This study investigated the impact of nitrogen fertilization on morphophysiological traits in maize(Zea mays L.)and developed algorithms to relate manual phenotyping and digital phenotyping of maize with leaf nitrogen and digital field image traits.The experiment included three hybrid maize varieties,V1(Hybrid 981),V2(BARI Hybrid maize-9),and V3(Hybrid P3396),which were evaluated across three nitrogen levels(N1=100 kg N ha^(−1),N2=200 kg N ha^(−1),N3=300 kg N ha^(−1))in a split-plot design with three replications.The results revealed that nitrogen levels(N),varieties(V),and their interactions(V×N)significantly influenced traits such as plant height(PH),leaf area index(LAI),normalized difference vegetation index(NDVI),canopy cover(CC),chlorophyll content(Chl a and Chl b),leaf nitrogen content(LNC),total dry matter(TDM),and grain yield.The hybrid P3396 with 300 kg N ha^(−1)(V3N3)achieved the highest grain yield of 14.45 t ha^(−1),which was statistically similar to that of Hybrid 981 and 300 kg N ha^(−1)(V1N3).Nitrogen significantly improved dry matter accumulation,leaf area,and physiological parameters,with maximum values recorded during flowering.The NDVI,CC,and SPAD were strongly correlated with LNC and TDM,highlighting their potential as indicators for nitrogen management.The digital imaging traits analysed via software effectively differentiated the nitrogen treatments,demonstrating their utility for precise nitrogen application.In conclusion,nitrogen fertilization at 300 kg N ha^(−1) optimized the growth and yield of hybrid maize,with Hybrid P3396 performing best.This study underscores the role of advanced phenotyping tools in improving nitrogen use efficiency and sustainable maize production.
基金The work was financially supported by the National Natural Science Foundation of China(No.31971636)Yong Elite Scientists Sponsorship Program by CAST(2018QNRC001)the Fundamental Research Fund for the Central Universities(2572018CG03).
文摘Investigating the effects of ontogenetic stage and leaf age on leaf traits is important for understanding the utilization and distribution of resources in the process of plant growth.However,few studies have been conducted to show how traits and trait-trait relationships change across a range of ontogenetic stage and leaf age for evergreen coniferous species.We divided 67 Pinus koraiensis Sieb.et Zucc.of various sizes(0.3-100 cm diameter at breast height,DBH)into four ontogenetic stages,i.e.,young trees,middle-aged trees,mature trees and over-mature trees,and measured the leaf mass per area(LMA),leaf dry matter content(LDMC),and mass-based leaf nitrogen content(N)and phosphorus content(P)of each leaf age group for each sampled tree.One-way analysis of variance(ANOVA)was used to describe the variation in leaf traits by ontogenetic stage and leaf age.The standardized major axis method was used to explore the effects of ontogenetic stage and leaf age on trait-trait relationships.We found that LMA and LDMC increased significantly and N and P decreased significantly with increases in the ontogenetic stage and leaf age.Most trait-trait relationships were consistent with the leaf economic spectrum(LES)at a global scale.Among them,leaf N content and LDMC showed a significant negative correlation,leaf N and P contents showed a significant positive correlation,and the absolute value of the slopes of the trait-trait relationships showed a gradually increasing trend with an increasing ontogenetic stage.LMA and LDMC showed a significant positive correlation,and the slopes of the trait-trait relationships showed a gradually decreasing trend with leaf age.Additionally,there were no significant relationships between leaf N content and LMA in most groups,which is contrary to the expectation of the LES.Overall,in the early ontogenetic stages and leaf ages,the leaf traits tend to be related to a"low investment-quick returns"resource strategy.In contrast,in the late ontogenetic stages and leaf ages,they tend to be related to a"high investment-slow returns"resource strategy.Our results reflect the optimal allocation of resources in Pinus koraiensis according to its functional needs during tree and leaf ontogeny.
