Photosynthetic and physiological responses of foxtail millet (Setaria italica L.) to low-light stress during grain-filling stage

作者：Xiangyang Yuan, L. G. Zhang, Lei Huang, Xiang Qi, Yixin Wen, Shuqi Dong, X. E. Song, Huifang Wang, Peng Guo · 发表于：Photosynthetica · 年份：2016 · DOI：10.1007/s11099-016-0645-4 · 被引用次数：18 · 研究领域：Photosynthetic Processes and Mechanisms、Plant responses to elevated CO2、Plant Stress Responses and Tolerance

Two foxtail millet (Setaria italica L.) varieties were subjected to different shading intensity treatments during a grain-filling stage in a field experiment in order to clarify physiological mechanisms of low-light effects on the yield. Our results showed that the grain fresh mass per panicle, yield, photosynthetic pigment contents, net photosynthetic rate, stomatal conductance, effective quantum yield of PSII photochemistry, and electron transport rate decreased with the increase of shading intensity, whereas the intercellular CO2 concentration increased in both varieties. In addition, shading changed a double-peak diurnal variation of photosynthesis to a one-peak curve. In conclusion, the lower yield of foxtail millet was caused mainly by a reduction of grain mass assimilated, a decline in chlorophyll content, and the low photosynthetic rate due to low light during the grain-filling stage. Reduced light energy absorption and conversion, restricted electron transfer, and reduced stomatal conductance might cause the decrease in photosynthesis.