【目的】探索北美海棠在南方地区的适应性和观赏性,为有效引种和培育新品种提供理论依据。【方法】以6个新优北美海棠品种(‘黛玉’、‘白兰地’、‘丰盛’、‘王族’、‘草莓果冻’和‘紫宝石’)为引种试材,在南方地区进行物候期、观赏性及耐热性观测和试验。【结果】6个北美海棠品种均能正常萌芽、展叶、开花、结果,且具有较高的观赏价值。夏季生长适应性观测显示,6个品种在南方高温环境下叶片出现不同程度的皱缩、卷曲、叶缘枯焦等变化。生理适应性表明,各品种均能通过自身质膜热稳定性、抗氧化系统及渗透调节方式应对南方夏季高温环境。【结论】6种北美海棠在南方地区夏季高温环境下生长受到一定影响,但通过自身的生理调节,能正常完成生活史,且表现出较高的观赏价值。引种的6种北美海棠表现最好的为‘黛玉’,其次是‘白兰地’和‘紫宝石’。南方地区可根据需要在苗木生产和景观绿化中选择适宜的北美海棠品种栽培。

【Objective】Explore the adaptability and ornamental value of north American crabapple cultivars grown in southern China, and provide a theoretical basis for the effective introduction and cultivation of new crabapple varieties.【Method】Six north American crabapple cultivars (Manus ‘Black Jade,’ M. ‘Brandywine,’ M. ‘Profusion,’ M. ‘Royalty,’ M. ‘Strawberry Jelly’ and M. ‘Purple Gems’) were grown in southern China, and their phenology, ornamental values and heat tolerance were recorded.【Result】All six crabapple cultivars were able to germinate, grow, blossom and bear fruit normally in southern China, and specimens had high ornamental value. Over the summer period, we documented leaf damage (shrinkage, curling and scorching to differing degrees) under high temperature conditions. However, plants were able to physiologically adapt to these temperatures owing to the high thermal stability of their plasma membranes, and the effectiveness of both their antioxidant systems and their osmotic regulation.【Conclusion】Growth of north American crabapple cultivars in southern China was affected by high summer temperatures; however, physiological regulation allowed plants to complete their normal life cycle. Plants exhibited phenotypes with high ornamental value. Of the cultivars, ‘Black Jade’ performed the best, followed by ‘Brandywine’ and ‘Purple Gems.’ We show that certain north American crabapple cultivars are suitable for introduction and cultivation in southern China, and specific cultivars can be selected according to individual requirements.