Effects of Water Stress on Leaf and Stem Water Potential of Two Different Stock-scion Young Apple Trees

摘要

In order to analyze demand water law and drought resistance of apple seedlings with different types of stock-scion combination,the dynamic changes of leaf and stem water potential of apple seedlings with 2 types of stock-scion under water stress were compared.A potting experiment was designed in 2 factors random block in a waterproofed shelter from April to November in 2011.The results showed that the stem water potential and leaf water potential can represent the water status in vivo and soil water regime of apple seedlings with 2 types of stock-scion; as the water stress became long and its extent increase,the stem and leaf water potential gradually reduced.The stem water potential was 0.10～0.20Mpa higher than leaf water potential at every corresponding moment of the same treatment.The variation trend of stem and leaf water potential was similar with that of soil water potential,which all showed a tendency to decrease,but there was a lag effect relative to soil water potential; the leaf and stem potential of Kangmutian/M26/Malus hupehensis pamp Reid (KM) was 15％ than that of Kangmutian/Malus hupehensis pamp Reid (KP).It indicates that drought resistance of KM was better than KP under light and middle water stress.