Jia Shi-fang, Dong Shu-ting, Wang Kong-jun, Zhang Ji-wang, Liu Peng
State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Taian 271018, Shandong, China.
Ying Yong Sheng Tai Xue Bao. 2007 Nov;18(11):2456-61.
Through shading at 0-14 days before pollination (S1), 1-14 days after pollination (S2), and 15-28 days after (S3) pollination, this paper studied the effects of weak light stress on the grain yield and photosynthetic traits of maize cultivars FY3 and TY2. The results showed that all treatments of shading induced a decreased grain yield, among which, treatment S1 had the largest decrement, and FY3 was more sensitive to the shading. Weak light stress made the time of maximum grain-filling (Tmax) appeared later, grain-filling slowed down, and mass accumulation decreased. The earlier the weak light stress occurred, the later the Tmax appeared. During shading, the Chl (a + b) content, Chl a/b ratio, photosynthetic rate (Pn) as well as the photochemical efficiency (Fv/Fm) and actual quantum yield of PS II electron transport (phi(PS II)) in maize leaves decreased significantly, while the relative content of Chl b increased, and the intercellular CO2 concentration (Ci) and non-photochemical quenching (NPQ) increased markedly. After the shading ended, the Chl (a + b) content, Chi a/b ratio, Pn, Fv/Fm, phi (PS II), Ci, and NPQ restored gradually to the levels of non-shading, but the relative content of Chl b decreased, which suggested that non-stomatal limitation was part of the reason for the decreased Pn under weak light stress.
通过在授粉前0 - 14天（S1）、授粉后1 - 14天（S2）和授粉后15 - 28天（S3）进行遮光处理，本文研究了弱光胁迫对玉米品种丰玉3号（FY3）和通育2号（TY2）籽粒产量及光合特性的影响。结果表明，所有遮光处理均导致籽粒产量下降，其中处理S1的降幅最大，且丰玉3号对遮光更敏感。弱光胁迫使最大灌浆时间（Tmax）出现延迟，灌浆速度减慢，物质积累减少。弱光胁迫发生越早，Tmax出现越晚。遮光期间，玉米叶片中叶绿素（Chl）（a + b）含量、Chl a/b比值、光合速率（Pn）以及光化学效率（Fv/Fm）和PSⅡ电子传递的实际量子产额（phi(PSⅡ)）显著降低，而Chl b的相对含量增加，细胞间CO2浓度（Ci）和非光化学猝灭（NPQ）显著增加。遮光结束后，Chl（a + b）含量、Chl a/b比值、Pn、Fv/Fm、phi(PSⅡ)、Ci和NPQ逐渐恢复到不遮光水平，但Chl b的相对含量降低，这表明非气孔限制是弱光胁迫下Pn降低的部分原因。
