播期对玉米光合特性及产量的影响

弄清播期对玉米光合特性及产量的影响可指导玉米高产栽培。以中熟型玉米‘科育15’为试材,采用分期播期试验,利用数理统计方法,分析了相关数据。不同播期玉米叶片的光合特性差异显著,随着播期推迟叶片净光合速率(Pn)、蒸腾速率(Tr)、叶绿素含量、水分利用效率(WUE)先增加后降低,胞间CO₂浓度(Ci)变化相反,气孔导度(Gs)无明显变化规律。Pn与Tr、WUE、Ta、PAR存在极显著的正相关,与Ci存在极显著的负相关,气温、光合有效辐射和土壤水分是影响玉米叶片净光合速率的主要气象因素;叶片光合参数间通过相互影响、协同作用影响玉米的生长和产量。适期播种可充分利用光、温、水等气候资源,促进光合效率、干物质积累及转化,显著增加产量。

Sowing Date and Yield of Maize: Effects on Photosynthetic Characteristics

The paper aims to understand the effects of sowing date on the photosynthetic characteristics and yield of maize and to guide the high-yield cultivation of maize. The sowing date test by stages was carried out with the medium ripening maize ‘Keyu15’, and the related data were analyzed with mathematical statistics methods. The results showed that, photosynthetic characteristics of maize leaves from different sowing dates were significantly different, the net photosynthetic rate (Pn), transpiration rate (Tr), chlorophyll content and water use efficiency (WUE) were increased first and then declined along with the sowing date delaying. While the concentration of CO₂ (Ci) had an opposite change, and stomatal conductivity (Gs) had no obvious change law. Pn had extremely significant positive correlation with Tr, WUE, Ta, PAR, and had extremely significant negative correlation with Ci. It was illustrated that the main meteorological factors affecting net photosynthetic rate of maize leaves were the air temperature, photosynthetic active radiation and soil moisture. The growth status and yield of maize were affected by the interaction and synergy between photosynthetic parameters of maize leaves. Suitable sowing date can make full use of climate resources, such as solar radiation, air temperature and water, and can improve photosynthetic efficiency and matter accumulation and transformation, and increase production significantly.