【摘要】 采用田间调查及人工模拟冰冻鉴定的方法，比较测定了4个桂花品种的抗冻性，其抗冻性强弱顺序为金桂（Osmanthusfragransvar．thunbergii）＞银桂（O．fragransvar.latifolius）＞丹桂（O．fragransvar．aurantiacus）＞四季桂（O．fragransvar.semperflorens）。筛选出5株抗冻性最强的单株，它们的致死温度都在－26℃左右。桂花叶片膜脂脂肪酸组成随季节呈周期性变化，随着气温下降亚麻酸（18∶3）含量增加而亚油酸（18∶2）含量降低。不同品种均表现出一致的变化趋势，抗性强的品种这种变化则更为显著。在自然脱锻炼过程中，叶面喷施脱落酸（200ppm）能使亚麻酸含量保持稳定，延缓桂花的脱锻炼。更多还原

【Abstract】 Freezing resistance of four varieties of Osmanthus fragrans Lour. were determined.Among them, O. fragrans var. thunbergii was the hardiest. The freezing resistance of the others were arranged in an order of O. fragrans var. latifolius, O. fragrans var. aurantzacus and O. fragrans var. semperfiorens. Five plants, Xuan-5, Zh-4,Zh-7, Zh-10 and Zh-8 were selected out as the hardiest ones among 19 trees tested,their LT50 temperature were about - 26℃. The composition of membrane fatty acid in the leaves were also measured. The results showed that the composition of membrane fatty acid in the leaves changed periodically with the change of growing seasons. The content of 18: 3 acid significantly increased whereas that of 18: 2 acid decreased as the air temperature dropped. The variation trends were much the same in various varieties,but it is more evident in hardy varieties. The content of 18: 3 acid in leaves treated with 200 ppm abscisic acid (ABA) maintained more steady during dehardening and delayed the dehardening processes of Osmanthus fragrans.更多还原