选取有代表性的12个水稻品种,研究分蘖期和灌浆期不同类型水稻之间光合作用的差异。结果表明:在分蘖期籼稻与粳稻的净光合速率(A)和气孔导度(gs)无显著差异,但常规稻大于杂交稻。粳稻的比叶重(specific leaf weight,SLW)、SPAD和叶片氮...选取有代表性的12个水稻品种,研究分蘖期和灌浆期不同类型水稻之间光合作用的差异。结果表明:在分蘖期籼稻与粳稻的净光合速率(A)和气孔导度(gs)无显著差异,但常规稻大于杂交稻。粳稻的比叶重(specific leaf weight,SLW)、SPAD和叶片氮素含量(Narea)基本都大于籼稻,但常规稻与杂交稻无显著差异。在灌浆期A和gs基本表现为常规籼稻>杂交籼稻>常规粳稻>杂交粳稻。2种氮肥处理下,常规稻的SPAD和Narea基本大于杂交稻。低氮处理下粳稻的SPAD和Narea大于籼稻,而高氮下籼稻与粳稻无显著差异。光合氮素利用效率(photosynthetic N use efficiency,PNUE)与SLW和非结构性碳水化合物(non-structural carbohydrate,NSC)含量均呈现出显著的负相关关系。因此,gs是造成不同品种之间A存在差异的主要原因,并且SLW、NSC是影响PNUE的主要因素。展开更多
Soil pot experiments were conducted in a greenhouse to examine the effects of different nitrogen （N） supply （low, 0.15 g N/kg; middle, 0.3 g N/kg; and high, 0.6 g N/kg dry soil） on the growth, photosynthetic chara...Soil pot experiments were conducted in a greenhouse to examine the effects of different nitrogen （N） supply （low, 0.15 g N/kg; middle, 0.3 g N/kg; and high, 0.6 g N/kg dry soil） on the growth, photosynthetic characteristics and photosynthetic nitrogen use efficiency （PNUE） of tobacco seedlings （Nicotiana tabacum L. Yunyan 87）. The results showed middle and high N significantly enhanced seedling growth including plant stem and leaf dry weight comparing with low N. High N supply could lead to a dramatic increase in the photosynthetic capacity of tobacco seedlings under low N conditions. There were significant differences in leaf N content between nitrogen treatments. About a 76% increase in leafN content in plants fed by high N resulted in about 43% increase in Rubisco content and 27% in net photosynthetic rate. The non-corresponding increases in photosynthetic rate in tobacco seedlings fed by high N relative to low N resulted from Rubisco activity and/or carboxylation efficiency （CE）. These results indicated that tobacco seedlings under high N application can maintain high net photosynthetic rate （Pn） but lower PNUE, will finally result in a decline in N use efficiency.展开更多
文摘选取有代表性的12个水稻品种,研究分蘖期和灌浆期不同类型水稻之间光合作用的差异。结果表明:在分蘖期籼稻与粳稻的净光合速率(A)和气孔导度(gs)无显著差异,但常规稻大于杂交稻。粳稻的比叶重(specific leaf weight,SLW)、SPAD和叶片氮素含量(Narea)基本都大于籼稻,但常规稻与杂交稻无显著差异。在灌浆期A和gs基本表现为常规籼稻>杂交籼稻>常规粳稻>杂交粳稻。2种氮肥处理下,常规稻的SPAD和Narea基本大于杂交稻。低氮处理下粳稻的SPAD和Narea大于籼稻,而高氮下籼稻与粳稻无显著差异。光合氮素利用效率(photosynthetic N use efficiency,PNUE)与SLW和非结构性碳水化合物(non-structural carbohydrate,NSC)含量均呈现出显著的负相关关系。因此,gs是造成不同品种之间A存在差异的主要原因,并且SLW、NSC是影响PNUE的主要因素。
文摘Soil pot experiments were conducted in a greenhouse to examine the effects of different nitrogen （N） supply （low, 0.15 g N/kg; middle, 0.3 g N/kg; and high, 0.6 g N/kg dry soil） on the growth, photosynthetic characteristics and photosynthetic nitrogen use efficiency （PNUE） of tobacco seedlings （Nicotiana tabacum L. Yunyan 87）. The results showed middle and high N significantly enhanced seedling growth including plant stem and leaf dry weight comparing with low N. High N supply could lead to a dramatic increase in the photosynthetic capacity of tobacco seedlings under low N conditions. There were significant differences in leaf N content between nitrogen treatments. About a 76% increase in leafN content in plants fed by high N resulted in about 43% increase in Rubisco content and 27% in net photosynthetic rate. The non-corresponding increases in photosynthetic rate in tobacco seedlings fed by high N relative to low N resulted from Rubisco activity and/or carboxylation efficiency （CE）. These results indicated that tobacco seedlings under high N application can maintain high net photosynthetic rate （Pn） but lower PNUE, will finally result in a decline in N use efficiency.
