锰和亚铁喷施对石门早硕板栗光合特性的影响

Effect of Foliage Application of MnSO_4 and FeSO_4 on Photosynthesis of Shimenzaoshuo Chestnut

以3a生石门早硕板栗为试材,研究叶面分别喷施w=0.3%的硫酸锰和硫酸亚铁溶液对其叶光合特性的影响。结果表明,喷施硫酸锰和硫酸亚铁2种溶液均明显提高了板栗幼树叶片的叶绿素含量﹑净光合速率和水分利用率等光合指标,硫酸亚铁处理幼树叶片的气孔导度和蒸腾速率也显著高于对照。分析各光合指标的日变化发现,板栗幼树叶片的净光合速率呈抛物线状,13:00时达到高峰值;对照幼树叶片的气孔导度及蒸腾速率值呈"M"型,而2种溶液处理均呈抛物线状。上述结果表明板栗幼树叶面喷施锰和亚铁溶液有助于增强其光合能力。

An experiment of foliage application of 0. 3% MnSO4 or 0. 3% FeSO4 solution to Shimenzaoshuo chestnut trees, three-year old, was conducted to explore effect of the foliage application on photosynthesis of the chestnut leaves. Photo- synthetic indexes, such as chlorophyll content, photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration, water use efficiency （WUE） and stomatal limitation were measured between 10：00 am and 11：00 am with SPAD-502 chlorophyll meter and CIRAS-2 photosynthetic instrument on sunny days. Results show that the application of either of the solutions increased chlorophyll content, photosynthetic rate and WUE of the chestnut leaves and the appli- cation of FeSO4 solution also improved stomatal conductance and transpiration rate of the trees. Analysis of the diurnal vari- ation of photosynthetic indices reveals that the net photosynthetic rate of the leaves of young chestnut trees varied following a curve of parabolic shape with a peak appearing at 1：00 pm. In CK, the stomatal conductance and the transpiration rate of the young chestnut leaves displayed a curve of ＂M＂ shape, while in the treatments of foliage application, they did a curve of parabolic shape, indicating that the foliage application of the solutions is conducive to enhancing photosynthetic capacity of the young chestnut tree leaves.