果树酸害的症状及生理敏感性

Studies on the Damaged Symptoms of Fruit Crops Caused by Acid Rain and Their Sensitivity

研究了葡萄、柑桔等１５种果树的酸害症状表现，并以Ｅｂｅｒｈａｒｔ－Ｒｕｓｓｅｌｌ模型分析了果树酸害的生理敏感性差异，结果表明：①叶片伤斑大多出现在叶脉之间，初期表现为失绿，呈水渍状，且边界模糊。伤斑颜色因果树不同而异，有黑褐色、棕色、灰白色等。受害重时导致伤斑穿孔或落叶。②不同果树对酸雨胁迫的相对敏感性不同：猕猴桃等５种果树属敏感类型；葡萄、樱桃属于中等敏感类型；枇杷等８种果树的相对敏感性较低。③ｐＨ ２．５～３．０是大多数果树产生显性伤害的酸度阈值，而ｐＨ３．５可作为隐性伤害阈值的参考。

The damaged symptoms of 15 kind of fruit crops caused by acid rain and their sensitivity to it were studied. The results indicated: (1)The symptoms were mostly characterized by spots scattered among leaf veins. These spots had a chlorotic and water-soaked appearance with vague boundaries during tieir initial stage of development. Spot color varied with kinds of fruit crops and might be dark brown, reddish brown, gray white, etc. Severe injury could lead to perforation at the spotted areas or even leaf drop. (2) Different kinds of fruit crops showed different sensitivity to acid rain stress. If the cell membrane permeability was used as the injury index when the Eberhart-Russell model was applied, kiwi fruit, plum, mume and peach was rated as the most sensitive trees, and grape and cherry the sub-sensitive ones, while fig, citrus, chestnut, jujube, apple, peach and loquat were comparatively insensitive. (3)The threshold pH value at which acid rain caused barely visible injury to leaves in most kinds of fruit crops was 2.5-3.0, and the pH 3. 5 may be considered the reference value for invisible injury.