本文旨在探明不同氮敏感性粳稻品种氮代谢与光合特性。以2个氮敏感高产品种淮稻5号和连粳7号,2个氮钝感品种宁粳1号和扬粳4038为材料,设置0和200 kg hm–2 2个施氮水平,研究其产量、氮肥利用效率以及地上部生理性状的变化特点。结果表明...本文旨在探明不同氮敏感性粳稻品种氮代谢与光合特性。以2个氮敏感高产品种淮稻5号和连粳7号,2个氮钝感品种宁粳1号和扬粳4038为材料,设置0和200 kg hm–2 2个施氮水平,研究其产量、氮肥利用效率以及地上部生理性状的变化特点。结果表明,在2种施氮水平下,氮敏感品种的产量和氮肥利用效率显著高于氮钝感品种。与氮钝感品种相比,氮敏感品种具有较高的光合速率和氮素积累,较强的氮代谢酶活性和较高的光合氮素利用效率,抽穗期茎叶中积累较多的可溶性糖和淀粉,抽穗至成熟期茎鞘中非结构性碳水化合物向籽粒转运率较高。表明氮敏感品种在较低施氮量下具有较高的生理活性和物质生产效率;这些特征可作为筛选高产氮敏感水稻品种的重要生理指标。展开更多
There are more than 2000 species of brittle stars in the world. For most of them, many scientific questions including basic characteristics of eco-physiology are still unknown. In the present study, Ophiopholis sarsii...There are more than 2000 species of brittle stars in the world. For most of them, many scientific questions including basic characteristics of eco-physiology are still unknown. In the present study, Ophiopholis sarsii vadicola acclimated at 15 ℃, salinity 31, were assessed for temperature monia excretion were studied at different temperatures （5, 10, and salinity tolerance. Its oxygen consumption and am- 15, 20, 25℃） and salinities （25, 30, 35）. O. sarsii vadi- cola could tolerate 0-24℃ and no brittle star was dead in the salinity range of 19-48 in the experimental situation. Two-way ANOVA showed that the oxygen consumption and ammonia excretion normalized with both dry mass and wet mass, Q10, which is used to describe the temperature sensitivity of respiration, and moisture content were significantly affected by temperature and salinity, and the combined effects of the two factors were significant. Stepwise multiple regression analysis revealed that logarithmic oxygen consumption and ammonia excretion showed a significant positive relationship with logarithmic temperature and salinity. The logarithmic moisture content of the brittle stars showed an inverse relationship with logarithmic salinity, but a positive relationship with logarithmic temperature. This suggests that the tolerance of temperature and salinity of brittle stars is closely related to their living environment, and that the effects of temperature on oxygen consumption are more significant at higher salinity, and that the ammonia excretion is less affected by salinity at lower temperatures.展开更多
Aims Prediction of changes in ecosystem gross primary productivity(GPP)in response to climatic variability is a core mission in the field of global change ecology.However,it remains a big challenge for the model commu...Aims Prediction of changes in ecosystem gross primary productivity(GPP)in response to climatic variability is a core mission in the field of global change ecology.However,it remains a big challenge for the model community to reproduce the interannual variation(IAV)of GPP in arid ecosystems.Accurate estimates of soil water content(SWC)and GPP sensitivity to SWC are the two most critical aspects for predicting the IAV of GPP in arid ecosystems.Methods We took a widely used model Biome-BGC as an example,to improve the model performances in a temperate grassland ecosystem.Firstly,we updated the estimation of SWC by modifying modules of evapotrainspiration,SWC vertical profile and field capacity.Secondly,we modified the function of controlling water-nitrogen relation,which regulates the GPP-SWC sensitivity.Important Findings The original Biome-BGC overestimated the SWC and underestimated the IAV of GPP sensitivity,resulting in lower IAV of GPP than the observations,e.g.it largely underestimated the reduction of GPP in drought years.In comparison,the modified model accurately reproduced the observed seasonal and IAVs in SWC,especially in the surface layer.Simulated GPP-SWC sensitivity was also enhanced and became closer to the observations by optimizing parameter controlling nitrogen mineralization.Consequently,the model's capability of reproducing IAV of GPP has been largely improved by the modifications.Our results demonstrate that SWC in the surface layer and the consequent effects on nitrogen availability should be among the first considerations for accurate modeling IAV of GPP in arid ecosystems.展开更多
文摘本文旨在探明不同氮敏感性粳稻品种氮代谢与光合特性。以2个氮敏感高产品种淮稻5号和连粳7号,2个氮钝感品种宁粳1号和扬粳4038为材料,设置0和200 kg hm–2 2个施氮水平,研究其产量、氮肥利用效率以及地上部生理性状的变化特点。结果表明,在2种施氮水平下,氮敏感品种的产量和氮肥利用效率显著高于氮钝感品种。与氮钝感品种相比,氮敏感品种具有较高的光合速率和氮素积累,较强的氮代谢酶活性和较高的光合氮素利用效率,抽穗期茎叶中积累较多的可溶性糖和淀粉,抽穗至成熟期茎鞘中非结构性碳水化合物向籽粒转运率较高。表明氮敏感品种在较低施氮量下具有较高的生理活性和物质生产效率;这些特征可作为筛选高产氮敏感水稻品种的重要生理指标。
基金supported by the National Basic Research Program of China (Grant No. 2011CB409805)the National Science & Technology Pillar Program (Grant No. 2011BAD13B06)+1 种基金Special Scientific Research Funds for Central Non-profit Institutes, Yellow Sea Fisheries Research Institute (20603022013042)the National Science and Technology Planning Project of China (Grant No. 2011BAD13B05)
文摘There are more than 2000 species of brittle stars in the world. For most of them, many scientific questions including basic characteristics of eco-physiology are still unknown. In the present study, Ophiopholis sarsii vadicola acclimated at 15 ℃, salinity 31, were assessed for temperature monia excretion were studied at different temperatures （5, 10, and salinity tolerance. Its oxygen consumption and am- 15, 20, 25℃） and salinities （25, 30, 35）. O. sarsii vadi- cola could tolerate 0-24℃ and no brittle star was dead in the salinity range of 19-48 in the experimental situation. Two-way ANOVA showed that the oxygen consumption and ammonia excretion normalized with both dry mass and wet mass, Q10, which is used to describe the temperature sensitivity of respiration, and moisture content were significantly affected by temperature and salinity, and the combined effects of the two factors were significant. Stepwise multiple regression analysis revealed that logarithmic oxygen consumption and ammonia excretion showed a significant positive relationship with logarithmic temperature and salinity. The logarithmic moisture content of the brittle stars showed an inverse relationship with logarithmic salinity, but a positive relationship with logarithmic temperature. This suggests that the tolerance of temperature and salinity of brittle stars is closely related to their living environment, and that the effects of temperature on oxygen consumption are more significant at higher salinity, and that the ammonia excretion is less affected by salinity at lower temperatures.
基金supported by the National Natural Science Foundation of China(31922053)the National Key Research and Development Program of China(2017YFA0604801).
文摘Aims Prediction of changes in ecosystem gross primary productivity(GPP)in response to climatic variability is a core mission in the field of global change ecology.However,it remains a big challenge for the model community to reproduce the interannual variation(IAV)of GPP in arid ecosystems.Accurate estimates of soil water content(SWC)and GPP sensitivity to SWC are the two most critical aspects for predicting the IAV of GPP in arid ecosystems.Methods We took a widely used model Biome-BGC as an example,to improve the model performances in a temperate grassland ecosystem.Firstly,we updated the estimation of SWC by modifying modules of evapotrainspiration,SWC vertical profile and field capacity.Secondly,we modified the function of controlling water-nitrogen relation,which regulates the GPP-SWC sensitivity.Important Findings The original Biome-BGC overestimated the SWC and underestimated the IAV of GPP sensitivity,resulting in lower IAV of GPP than the observations,e.g.it largely underestimated the reduction of GPP in drought years.In comparison,the modified model accurately reproduced the observed seasonal and IAVs in SWC,especially in the surface layer.Simulated GPP-SWC sensitivity was also enhanced and became closer to the observations by optimizing parameter controlling nitrogen mineralization.Consequently,the model's capability of reproducing IAV of GPP has been largely improved by the modifications.Our results demonstrate that SWC in the surface layer and the consequent effects on nitrogen availability should be among the first considerations for accurate modeling IAV of GPP in arid ecosystems.
