在-5℃低温胁迫下 ,夏威夷椰子 (Pritchardia gaudichaudii H .Wendl.)幼苗叶片的丙二醛 (MDA)含量逐渐增加 ,表明膜脂过氧化作用逐渐增强 ;含水量不断下降 ;细胞保护酶中的超氧化物歧化酶 (SOD)、过氧化物酶 (POD)和过氧化氢酶 (CAT)酶活性均先升高 ,然后下降。冷锻炼处理可以减缓夏威夷椰子膜脂过氧化作用的增强 ,促进SOD酶活性的提高 ,同时抑制POD和CAT酶活性的变化 ,因而使夏威夷椰子幼苗的抗寒性得以提高 ,在-5℃低温胁迫下的半致死时间从 1.6d延长到2 .2d。 

Under -5℃low temperature stress, malondialdehyde ( MDA)content in leaves of Pritchardia gaudichaudii H.Wendl. seedling gradually increased , reflecting that membrane lipid peroxidation aggravated. Water content lowered. Cell defense enzymes SOD ( superoxide dimutase) , POD ( peroxidase)and CAT ( catalase)activity raised at early stage, and then lowered. Cold hardening treatment could lessen the increase of membrane lipid peroxidation, promote SOD activity, and inhibite the change of POD and CAT activity under low temperature stress, so the resistance to chilling stress had been enhanced for P. gaudichaudii seedling. By cold hardening, the half lethal time had been extended to 2. 2 d from 1.6 d under -5℃low temperature stress.