Zhao Wei, Xu Zheng, Gao Da Peng, An Zhen, Gao Hui Yuan, Zhang Zi Shan, Ning Tang Yuan, Li Geng
College of Agronomy, Shandong Agricultural University/State Key Laboratory of Crop Biology, Tai'an 271018, Shandong, China.
College of Life Science, Shandong Agricultural University, Tai'an 271018, Shandong, China.
Ying Yong Sheng Tai Xue Bao. 2019 Aug;30(8):2707-2716. doi: 10.13287/j.1001-9332.201908.023.
To improve light environment, photosynthetic capacity, and thus the yield of maize, the effects of directional planting on light distribution in canopy and photosynthetic characteristics of ear leaves, as well as the performance of PSII that closely related with photosynthetic characteristics and reflected by the rapid chlorophyll fluorescence kinetic curves were examined in Zhengdan 958 maize variety. The results showed that the orientation of leaves remarkably affected photosynthetically active radiation (PAR) interception of ear leaves, with PAR interception of ear leaves in southward treatment being 271.8% higher than that under northward treatment. The orientation of leaves affec-ted photosynthetic light use efficiency of ear leaves under high and low light conditions. The southward treatment increased net photosynthetic rate (P) under saturated light in ear leaves, indicating that the use efficiency to high light was enhanced in leaves of southward treatment. In contrast, the northward treatment increased the apparent quantum yield (α) of ear leaves, indicating leaves in southward treatment adapted the light-limited environment. During the early stage after anthesis, the performance of PSII electron donor side and electron acceptor side was significantly improved, and thus enhanced the performance of PSII reaction center (PI) and fluorescence photochemical quenching coefficient (Ψ) in ear leaves of southward treatment. The increase of quantum yield of electron transfer (φ) indicated the enhancement of transfer performance of electrons from photosystem 2 (PSII) to photosystem 1 (PSI) in leaves of southward treatment. The photosynthetic performance of ear leaves showed a trend of southward > eastward > westward > northward during the early stage after anthesis. Forty days after anthesis, the use efficiency to high light decreased in ear leaves of southward treatment, but the ear leaves of southward treatment showed high use efficiency to low light, which changed the trend of photosynthetic performance of ear leaves to northward > westward > eastward > southward. In summary, northward and eastward treatments improved the light distribution in canopy, the PAR interception of ear leaves, the capacity of photosynthesis and dry matter production, and consequently increased the yield of summer maize.
为改善光照环境、光合能力，进而提高玉米产量，以郑单958玉米品种为材料，研究了定向种植对冠层光分布、穗位叶光合特性以及与光合特性密切相关并由快速叶绿素荧光动力学曲线反映的PSII性能的影响。结果表明，叶片方向显著影响穗位叶光合有效辐射（PAR）截获量，南向处理穗位叶PAR截获量比北向处理高271.8%。叶片方向影响穗位叶在高光和低光条件下的光合光利用效率。南向处理提高了穗位叶在饱和光下的净光合速率（P），表明南向处理叶片对强光的利用效率提高。相反，北向处理提高了穗位叶的表观量子产额（α），表明南向处理叶片适应弱光环境。在开花后早期，南向处理穗位叶PSII电子供体侧和电子受体侧性能显著改善，从而提高了穗位叶PSII反应中心性能（PI）和荧光光化学猝灭系数（Ψ）。电子传递量子产额（φ）的增加表明南向处理叶片中从光系统2（PSII）到光系统1（PSI）的电子传递性能增强。开花后早期穗位叶光合性能表现为南向＞东向＞西向＞北向。开花后40天，南向处理穗位叶对强光的利用效率降低，但对弱光的利用效率较高，穗位叶光合性能趋势变为北向＞西向＞东向＞南向。综上所述，北向和东向处理改善了冠层光分布、穗位叶PAR截获量、光合作用和干物质生产能力，从而提高了夏玉米产量。
