木兰科6个树种抗旱性及其抗氧化指标的测定

将木兰科6个树种进行28 d春旱处理,以观察田间生长状况,并测定土壤含水量及树种凋萎系数;干旱处理21 d时,测定植株叶片的抗氧化指标。结果表明:阔瓣含笑、乐昌含笑暂时凋萎系数均为7.6%,永久凋萎系数均为3.78%;金叶含笑、观光木、红花木莲、桂南木莲暂时凋萎系数均为14.2%,永久凋萎系数均为7.6%。根据以上结果及田间观察,6个供试树种抗旱能力由大到小排序为:阔瓣含笑、乐昌含笑、金叶含笑、观光木、桂南木莲、红花木莲。抗氧化指标测定结果显示:水分胁迫21d时,观光木和红花木莲总抗氧化能力有所降低,其余4个树种均升高;而抗坏血酸(Vc)和还原型谷胱甘肽(GSH)含量在6个树种中均升高。其中,阔瓣含笑和乐昌含笑升高幅度最大。

Study on drought resistance of six tree species in Magnoliaceae as well as variation of their anti-oxidization indices

Experiments were committed on six tree species in Magnoliaceae suffered from spring drought for 28 days.Their growth were observed in field and the soil contents of water and the wilting coefficients of them were determined.After the duration of three weeks with spring drought,some anti-oxidization indices of them were also tested.The results showed that the temporary wilting coefficients of Michelia platypetala and Michelia chapensis were 7.6% and the permanent wilting coefficients of them 3.78% while the temporary wilting coefficients of Michelia foreolate,Tsoongiodendron odorum,Manglietia insignis and Manglietia chingii were 14.02% and the permanent wilting coefficients 7.6%.According to these results and their field observation,the descending order of drought resistance was M.platypetala,M.chapensis,M.foreolate,T.odorum,Manglietia chingii and M.insignis.It was demonstrated from anti-oxidization indices that when stressed for three weeks,the activity of total anti-oxidation of T.odorum and M.insignis decreased while that of the others increased.However,the contents of Vc and GSH in all tree species tested increased,among which the increasing degrees of M.platypetala and M.chapensis were the highest.