水分胁迫对苹果不同品种光合特性的影响

Effect of Soil Water Stress on Photosynthesis of Different Apple Cultivars

研究了苹果7个品种一年生嫁接苗叶片净光合速率(Pn)、蒸腾速率(Tr)、水分利用率(WUE)、气孔导度(GS)等指标对土壤水分胁迫的响应。土壤干旱胁迫时苹果上述生理过程均受到显著影响,但各项生理指标对水分胁迫的敏感性不同。随着水分胁迫加剧,净光合速率、蒸腾速率、气孔导度均表现为下降的趋势,而水分利用率先升高后降低。不同品种的光合和蒸腾性能指标对水分胁迫的响应不同,抗旱性强的品种在胁迫条件下净光合速率、蒸腾速率、气孔导度均较低,且下降的幅度大;抗旱性强的品种在中度胁迫条件下水分利用率高,且升高的幅度大。

The responses of main photosynthesis, transpiration, water useefficiency and stomata conduct indexes of eight cultivars to soil water stress were studied with one-year-old grafting trees. The physiological indexes were significantly affected by soil water stress but different sensitivity of each index was shown. As stress increases, net photosynthesis rate, transpiration, stomata conduct were gradually decreased but water use efficiency was first increased, and decreased afterward. Different cultivars showed different photosynthesis and transpiration responses to water stress. The net photosynthesis rate, transpira- tion rate and stomata conduct indexes of cultivars that had stronger drought resistance were all lower than ck under water stress, and the range of descent was significant; water use efficiency of cultivars that had stronger drought resistance was higher than ck under moderate water stress, and the range of ascent was significant.