不同桉树无性系幼苗对离体干旱胁迫的生理响应

Physiological Response of Different Eucalyptus Clone Seedlings on In Vitro Drought Stress

[目的]筛选抗旱能力较强的桉树无性系。[方法]以8个不同桉树无性系(GL-U4、GL-WC3、DH184-1、DH201-2、DH33-27、DH32-26、DH32-28、GL-UG9)幼苗的叶片为材料,将叶片离体后分别进行0、2、4、8、12和24 h的干旱胁迫处理,以正常生长的苗木鲜叶为对照,研究干旱胁迫对叶片相对含水量(RWC)、游离脯氨酸(Pro)含量、超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量的影响。[结果]随着离体失水时间的延长,幼苗叶片RWC下降,细胞质膜透性增加,膜脂过氧化程度加剧,MDA和Pro含量增加,SOD活性降低;8个无性系中,GL-U4、GL-WC3和DH184-1的抗旱能力较强,H201-2和DH33-27的抗旱能力较弱。[结论]总体来看,8个桉树无性系的渗透调节系统较发达,而膜系统保护酶的防御能力较弱。

[ Objective ] The aim was to screen Eucalyptus clone with strong dreught-resistant ability. [ Method ] With 8 Eucalyptus clone seedlings （GL-U4, GL-WC3, DH184-1, DH201-2, DH33-27, DH32-26, DH32-28, GL-UG9） as the materials, their leaves in vitro were treated with drought stress, with fresh leaves of normal growth seedlings as CK, the effects of drought stress on relative water content （RWC）, free proline （Pro） content, superoxide dismutase （SOD） activity and malondialdehyde （MDA） content of Eucalyptus leaves were studied. [ Result] With the delay of in vitro water loss time, the RWC of seedling leaves decreased, cell membrane permeability increased, membrane lipid peroxide level aggravated, MDA and Pro contents increased and SOD activity decreased. Among the 8 Eucalyptus clones, the drought-resistant abilities of GL-U4, GL-WC3 and DH184-1 were strong, and those of H201-2 and DH33-27 were weak. [ Conclusion] As a whole, the osmoregulatory systems of 8 Eucalyptus clones were more developed, but the defense abilities of their membrane system protective enzyme were weak.