地表覆盖反光膜对红肉蜜柚叶片气体交换的影响

Effects of Reflective Film Mulching on the Diurnal Variation of Leaf Gas Exchange of Citrus grandis 'Red-fleshed sweet pomelo'

为改善蜜柚种植园温光条件,提高果实品质,对5年生红肉蜜柚树进行地表覆盖反光膜栽培,研究无孔银色反光薄膜、有孔银色反光薄膜对红肉蜜柚内膛叶和树冠叶的气体交换(净光合速率、蒸腾速率、气孔导度、胞间CO2浓度)日变化的影响。结果表明:两种覆膜处理能使柚树内膛的光照强度在6:00-18:00显著高于对照(不覆膜);内膛叶的净光合速率在10:00-14:00高于对照,树冠叶净光合速率在8:00-12:00低于对照;覆膜能提高内膛叶和树冠叶的蒸腾速率;内膛叶的气孔导度在6:00-10:00高于对照,树冠叶的气孔导度与对照相似;覆膜的胞间CO2浓度总体高于对照。无孔银色反光薄膜、有孔银色反光薄膜间各指标差异不明显。

In order to improve the temperature and light conditions of Citrus grandis'Red-fleshed sweet pomelo'orchard,5-year-old trees were mulched with the silver reflective films(nonporous or porous)under the tree canopy during fruit development,and the gas exchange of leaves in the lower and on canopy of tree were investigated respectively.The results showed that compared to the control(without reflective film),two reflective film mulching treatments increased significantly the light intensities of the lower of tree during 6:00-18:00.The net photosynthetic rate(Pn)of leaf in the lower of tree with reflective film mulching was higher than the control during 10:00-14:00,but the Pn of canopy leaves was lower than the control during 8:00-12:00.Also two reflective film mulching increased the transpiration rates of leaves in lower and on canopy of tree.The stomatal conductances of the lower leaves of treeby reflective film mulching treatments were higher than the control during 6:00-10:00,but it was no different for canopy leaves.The intercellular CO 2 concentration were improved by film mulching.There were no marked difference between nonporous and porous film mulching.