In this study, 14 wheat cultivars with contrasting yield and N use efficiency （NUE） were used to investigate the agronomic and NUE-related traits, and the N assimilation-associated enzyme activities under low and hi...In this study, 14 wheat cultivars with contrasting yield and N use efficiency （NUE） were used to investigate the agronomic and NUE-related traits, and the N assimilation-associated enzyme activities under low and high N conditions. Under deficient-N, the cultivars with high N uptake efficiency （UpE） and high N utilization efficiency （UtE） exhibited higher plant biomass, yields, and N contents than those with medium and low NUEs. The high UpE cultivars accumulated more N than other NUE type cultivars. Under sufficient-N, the tested cultivars showed similar patterns in biomass, yield, and N content to those under deficient-N, but the varietal variations in above traits were smaller. In addition, the high UpE cultivars displayed much more of root biomass and larger of root length, surface area, and volume than other NUE type cultivars, indicating that the root morphological traits under N deprivation are closely associated with the plant biomass through its improvement of the N acquisition. The high UtE cultivars showed higher activities of nitrate reductase （NR）, nitrite reductase （NIR）, and gluta- mine synthetase （GS） at stages of seediling, heading and filling than other NUE type cultivars under both low and high N conditions. Moreover, the high UpE and UtE cultivars also displayed higher photosynthetic rate under deficient-N than the medium and low NUE cultivars. Together, our results indicated that the tested wheat cultivars possess dramatically genetic variations in biomass, yield, and NUE. The root morphological traits and the N assimilation enzymatic acitivities play critical roles in regulating N accumulation and internal N translocation under the N-starvation stress, respectively. They can be used as morphological and biochemical references for evaluation of UpE and UtE in wheat.展开更多
With a continuously increasing population and better food consumption levels, im- proving the efficiency of arable land use and increasing its productivity have become funda- mental strategies to meet the growing food...With a continuously increasing population and better food consumption levels, im- proving the efficiency of arable land use and increasing its productivity have become funda- mental strategies to meet the growing food security needs in China. A spatial distribution map of medium- and low-yield cropland is necessary to implement plans for cropland improvement In this study, we developed a new method to identify high-, medium-, and low-yield cropland from Moderate Resolution Imaging Spectroradiometer （MODIS） data at a spatial resolution of 500 m. The method could be used to reflect the regional heterogeneity of cropland productiv- ity because the classification standard was based on the regionalization of cropping systems in China. The results showed that the proportion of high-, medium-, and low-yield cropland in China was 21%, 39%, and 40%, respectively. About 75% of the low-yield cropland was lo- cated in hilly and mountainous areas, and about 53% of the high-yield cropland was located in plain areas. The five provinces with the largest area of high-yield cropland were all located in the Huang-Huai-Hai region, and the area amounted to 42% of the national high-yield cropland area. Meanwhile, the proportion of high-yield cropland was lower than 15% in Hei- Iongjiang, Sichuan, and Inner Mongolia, which had the largest area allocated to cropland in China. If all the medium-yield cropland could be improved to the productive level of high-yield cropland and the low-yield cropland could be improved to the level of medium-yield cropland, the total productivity of the land would increase 19% and 24%, respectively.展开更多
Breeding high-yielding and nutrient-efficient cultivars is one strategy to simultaneously resolve the problems of food security,resource shortage,and environmental pollution.However,the potential increased yield and r...Breeding high-yielding and nutrient-efficient cultivars is one strategy to simultaneously resolve the problems of food security,resource shortage,and environmental pollution.However,the potential increased yield and reduction in fertilizer input achievable by using high-yielding and nutrient-efficient cultivars is unclear.In the present study,we evaluated the yield and nitrogen use efficiency(NUE) of 40 commercial maize hybrids at five locations in North and Northeast China in 2008 and 2009.The effect of interaction between genotype and nitrogen(N) input on maize yield was significant when the yield reduction under low-N treatment was 25%-60%.Based on the average yields achieved with high or low N application,the tested cultivars were classified into four types based on their NUE:efficient-efficient(EE) were efficient under both low and high N inputs,high-N efficient(HNE) under only high N input,low-N efficient(LNE) under only low N input,and nonefficient-nonefficient under neither low nor high N inputs.Under high N application,EE and HNE cultivars could potentially increase maize yield by 8%-10% and reduce N input by 16%-21%.Under low N application,LNE cultivars could potentially increase maize yield by 12%.We concluded that breeding for N-efficient cultivars is a feasible strategy to increase maize yield and/or reduce N input.展开更多
以氮效率不同的2个小麦品种郑麦0943(氮利用效率指数为1.557)和周麦18(氮利用效率指数为0.895)为试验材料,研究低氮胁迫对2个小麦品种净光合速率、氮积累量、氮代谢酶活性、根系性状、产量和品质的影响,以期为小麦氮高效育种和节本高效...以氮效率不同的2个小麦品种郑麦0943(氮利用效率指数为1.557)和周麦18(氮利用效率指数为0.895)为试验材料,研究低氮胁迫对2个小麦品种净光合速率、氮积累量、氮代谢酶活性、根系性状、产量和品质的影响,以期为小麦氮高效育种和节本高效栽培技术研发提供参考。结果表明,在正常供氮和低氮处理下,郑麦0943花后7、14、21 d的净光合速率,花后14 d 10:00—15:00的净光合速率、硝酸还原酶和谷氨酰胺合成酶活性,成熟期秸秆和籽粒氮积累量,产量均显著高于周麦18;低氮处理下,上述指标均显著低于正常供氮处理,且郑麦0943的降低幅度低于周麦18,其中,郑麦0943产量降低21.40%,周麦18降低24.87%。低氮处理下,郑麦0943的总根长、根表面积和根系活力均显著高于周麦18;2个小麦品种根系性状均显著高于正常供氮处理,且郑麦0943的提高幅度高于周麦18。低氮胁迫显著影响2个小麦品种的品质,郑麦0943的品质受影响较小,低氮处理下郑麦0943的蛋白质含量、湿面筋含量、稳定时间、最大拉伸阻力、拉伸面积等指标较正常供氮处理的降幅均低于周麦18,除拉伸面积外,其余指标均达到了中强筋小麦标准。综上,郑麦0943较周麦18更耐低氮,低氮对其光合速率、氮积累量、氮代谢酶活性、根系、产量和品质的影响更小,低氮下其具有更好的光合特性、更高的氮吸收和同化能力、更发达的根系,进而获得更高的产量和较优的品质。展开更多
基金supported by the Chinese National Programs of Science and Technology for High Yielding Crop Production (2011BAD16B08, 2012BAD04B06, and 2013BAD07B05)the Key Laboratory of Crop Growth Regulation of Hebei Province, China
文摘In this study, 14 wheat cultivars with contrasting yield and N use efficiency （NUE） were used to investigate the agronomic and NUE-related traits, and the N assimilation-associated enzyme activities under low and high N conditions. Under deficient-N, the cultivars with high N uptake efficiency （UpE） and high N utilization efficiency （UtE） exhibited higher plant biomass, yields, and N contents than those with medium and low NUEs. The high UpE cultivars accumulated more N than other NUE type cultivars. Under sufficient-N, the tested cultivars showed similar patterns in biomass, yield, and N content to those under deficient-N, but the varietal variations in above traits were smaller. In addition, the high UpE cultivars displayed much more of root biomass and larger of root length, surface area, and volume than other NUE type cultivars, indicating that the root morphological traits under N deprivation are closely associated with the plant biomass through its improvement of the N acquisition. The high UtE cultivars showed higher activities of nitrate reductase （NR）, nitrite reductase （NIR）, and gluta- mine synthetase （GS） at stages of seediling, heading and filling than other NUE type cultivars under both low and high N conditions. Moreover, the high UpE and UtE cultivars also displayed higher photosynthetic rate under deficient-N than the medium and low NUE cultivars. Together, our results indicated that the tested wheat cultivars possess dramatically genetic variations in biomass, yield, and NUE. The root morphological traits and the N assimilation enzymatic acitivities play critical roles in regulating N accumulation and internal N translocation under the N-starvation stress, respectively. They can be used as morphological and biochemical references for evaluation of UpE and UtE in wheat.
基金STS Project of CAS,No.KFJ-EW-STS-001National Natural Science Foundation of China,No.41430861
文摘With a continuously increasing population and better food consumption levels, im- proving the efficiency of arable land use and increasing its productivity have become funda- mental strategies to meet the growing food security needs in China. A spatial distribution map of medium- and low-yield cropland is necessary to implement plans for cropland improvement In this study, we developed a new method to identify high-, medium-, and low-yield cropland from Moderate Resolution Imaging Spectroradiometer （MODIS） data at a spatial resolution of 500 m. The method could be used to reflect the regional heterogeneity of cropland productiv- ity because the classification standard was based on the regionalization of cropping systems in China. The results showed that the proportion of high-, medium-, and low-yield cropland in China was 21%, 39%, and 40%, respectively. About 75% of the low-yield cropland was lo- cated in hilly and mountainous areas, and about 53% of the high-yield cropland was located in plain areas. The five provinces with the largest area of high-yield cropland were all located in the Huang-Huai-Hai region, and the area amounted to 42% of the national high-yield cropland area. Meanwhile, the proportion of high-yield cropland was lower than 15% in Hei- Iongjiang, Sichuan, and Inner Mongolia, which had the largest area allocated to cropland in China. If all the medium-yield cropland could be improved to the productive level of high-yield cropland and the low-yield cropland could be improved to the level of medium-yield cropland, the total productivity of the land would increase 19% and 24%, respectively.
基金supported by the National Basic Research Program of China (2011CB100305,2009CB11860)the National Natural Science Foundation of China (31121062,31172015)the Special Fund for Agriculture Profession (201103003)
文摘Breeding high-yielding and nutrient-efficient cultivars is one strategy to simultaneously resolve the problems of food security,resource shortage,and environmental pollution.However,the potential increased yield and reduction in fertilizer input achievable by using high-yielding and nutrient-efficient cultivars is unclear.In the present study,we evaluated the yield and nitrogen use efficiency(NUE) of 40 commercial maize hybrids at five locations in North and Northeast China in 2008 and 2009.The effect of interaction between genotype and nitrogen(N) input on maize yield was significant when the yield reduction under low-N treatment was 25%-60%.Based on the average yields achieved with high or low N application,the tested cultivars were classified into four types based on their NUE:efficient-efficient(EE) were efficient under both low and high N inputs,high-N efficient(HNE) under only high N input,low-N efficient(LNE) under only low N input,and nonefficient-nonefficient under neither low nor high N inputs.Under high N application,EE and HNE cultivars could potentially increase maize yield by 8%-10% and reduce N input by 16%-21%.Under low N application,LNE cultivars could potentially increase maize yield by 12%.We concluded that breeding for N-efficient cultivars is a feasible strategy to increase maize yield and/or reduce N input.
文摘以氮效率不同的2个小麦品种郑麦0943(氮利用效率指数为1.557)和周麦18(氮利用效率指数为0.895)为试验材料,研究低氮胁迫对2个小麦品种净光合速率、氮积累量、氮代谢酶活性、根系性状、产量和品质的影响,以期为小麦氮高效育种和节本高效栽培技术研发提供参考。结果表明,在正常供氮和低氮处理下,郑麦0943花后7、14、21 d的净光合速率,花后14 d 10:00—15:00的净光合速率、硝酸还原酶和谷氨酰胺合成酶活性,成熟期秸秆和籽粒氮积累量,产量均显著高于周麦18;低氮处理下,上述指标均显著低于正常供氮处理,且郑麦0943的降低幅度低于周麦18,其中,郑麦0943产量降低21.40%,周麦18降低24.87%。低氮处理下,郑麦0943的总根长、根表面积和根系活力均显著高于周麦18;2个小麦品种根系性状均显著高于正常供氮处理,且郑麦0943的提高幅度高于周麦18。低氮胁迫显著影响2个小麦品种的品质,郑麦0943的品质受影响较小,低氮处理下郑麦0943的蛋白质含量、湿面筋含量、稳定时间、最大拉伸阻力、拉伸面积等指标较正常供氮处理的降幅均低于周麦18,除拉伸面积外,其余指标均达到了中强筋小麦标准。综上,郑麦0943较周麦18更耐低氮,低氮对其光合速率、氮积累量、氮代谢酶活性、根系、产量和品质的影响更小,低氮下其具有更好的光合特性、更高的氮吸收和同化能力、更发达的根系,进而获得更高的产量和较优的品质。
