Biomass accumulation and partitioning, photosynthesis, and photosynthetic induction in field-grown maize (Zea mays L.) under low- and high-nitrogen conditions
Biomass accumulation and partitioning, photosynthesis, and photosynthetic induction in field-grown maize (Zea mays L.) under low- and high-nitrogen conditions
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DOI：
10.1007/s11738-012-1051-6
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发表时间：
2013-01-01
影响因子：
2.6
通讯作者：
An, Tong-Xin
中科院分区：
文献类型：
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作者：
Chen, Jun-Wen;Yang, Zhi-Qing;An, Tong-Xin
本研究旨在研究生物量积累和分配对氮素供应的响应，以及低氮供应对玉米叶片对稳态光和动态光的光合作用响应的影响。叶片数和茎粗差异不显著，但株高差异显著。灌浆期，低氮玉米植株的最大光合速率、最大气孔导度、最大蒸腾速率、表观量子效率、光补偿点和羧化效率均低于高氮玉米植株。相反，高氮玉米植株的胞间CO2浓度和暗呼吸速率较低。此外，低氮玉米植株的穗部叶片对模拟太阳斑的响应较慢；但在光合作用诱导过程中，高氮或低氮玉米植株的穗部叶片不存在气孔限制。与高氮玉米植株相比，低氮玉米植株积累的植株生物量少得多，但将更大比例的生物量分配到地下部分。综上所述，我们的结果表明，低氮玉米植株的稳态光合作用能力受到生化限制和气孔限制的共同制约，而光合作用的诱导仅受生化限制的限制，玉米作物对低氮供应的响应方式是将更多的生物量优先分配给根组织。
The objectives of this comparative study were to investigate the responses of biomass accumulation and partitioning to nitrogen supply and to examine the effect of low-nitrogen supply on the photosynthetic responses of maize leaves to steady-state and dynamic light. While the difference in leaf number and stem diameter was not statistically significant, there was a significant difference in plant height between the low-nitrogen and high-nitrogen maize plants. During grain-filling period, the ear leaf of the low-nitrogen maize plants possessed lower values of maximum photosynthetic rate, maximum stomatal conductance, maximum transpiration rate, apparent quantum yield, light compensate point, and carboxylation efficiency than did that of the high-nitrogen maize plants. Contrarily, lower values of intercellular CO2 concentration and dark respiration rate were observed in the high-nitrogen maize plants. In addition, a slower response to simulated sunflecks was found in the ear leaf of the low-nitrogen maize plants; however, stomatal limitations did not operate in the ear leaf of the high-nitrogen or low-nitrogen maize plants during the photosynthetic induction. As compared to the high-nitrogen maize plants, the low-nitrogen maize plants accumulated much less plant biomass but allocated a greater proportion of biomass to belowground parts. In conclusion, our results suggested that steady-state photosynthetic capacity is restricted by both biochemical and stomatal limitation and the photosynthetic induction is constrained by biochemical limitation alone in low-nitrogen maize plants, and that maize crops respond to low-nitrogen supply in a manner by which more biomass was allocated preferentially to root tissues.