关键词: 苹果, 砧木, 连作, 适应性, 光合速率, 抗氧化物酶

Abstract: Five rootstocks，i.e. Malus sieversii（Ledeb.）Roem.，M. micromalus Makino，M. hupehensis Rehd.，M. baccata（L.）Borkh. and M. micromalus were used to compare their difference in adaptability to replant soil with pot trials，with potted rootstocks in non-replant soil as control. The results indicated that the photosynthesis rate and phytochrome content in leaves of all rootstocks potted in replant soil were rather lower than the control. Among them，M. hupehensis Rehd. exhibited the lowest decrease in photosynthesis rate，chlorophyll and carotinoid contents，i.e. 7.06%，9.15% and 8.17%，respectively. In contrast，antioxidant enzymes and malondialdehyde（MDA）in roots of apple rootstocks in replant soil increased compared to their respective control. Among them，activities of superoxide dismutase（SOD），peroxidase（POD），catalase（CAT）in roots of M. hupehensis Rehd. in replant soil showed the least increase，3.72%，26.60% and 23.78%，respectively，relative to the control. In addition，MDA content increased by 15.24% in replanted M. hupehensis rootstocks as well. On the contrary，MDA content in M. micromalus Makino increased up to the greatest value of 54.56%. As a result，replant made declines in biomass，plant height and ground diameter for all 5 rootstocks tested. In conclusion，on the basis of the above experimental results，M. hupehensis Rehd. showed a better tolerance to apple replant disease among all 5 rootstocks tested.

Key words: apple, rootstock, replant, adaptation, photosynthesis rate, antioxidant enzyme