自然干旱胁迫及复水处理对红秆寒竹生理特性的影响

干旱胁迫是影响植物生长发育及园林应用的重要因子。为掌握红秆寒竹Chimonobambusa marmorea f. variegata 的抗旱能力及其抗旱机制，于温室内测定了其自然干旱及复水后的叶绿素（Chl）质量分数、超氧化物歧化酶（SOD）活性、过氧化氢酶（CAT）活性、丙二醛（MDA）质量摩尔浓度。结果表明：随着干旱胁迫时间的延长，叶绿素质量分数从4.470 mg·g^－1降到1.807 mg·g^－1，干旱处理30 d后一直比较稳定。随着干旱胁迫加强，CAT和SOD活性、丙二醛质量摩尔浓度均呈增加的趋势，在处理30 d后。CAT和SOD活性均维持在较高且稳定的水平，丙二醛质量摩尔浓度在40 d时达到最高水平。复水5 d后，叶绿素质量分数和CAT活性基本不变，SOD活性和丙二醛质量摩尔浓度则有所下降。红秆寒竹叶片细胞膜自我修复能力较强，具有较强的抗干旱能力。图1表2参14

Physiological characteristics of Chimonobambusa marmorea f. Varie gata with natural drought stress and rewetting

To understand drought resistance capacity of Chimonobambusa marmorea f. variegata and how it occurs, the dynamics of C. marmorea f. variegata and its levels of superoxide dismutase （SOD）, catalase （CAT）, malondialdehyde （MDA）, and chlorophyll were determined with leaves experiencing conditions of natural drought and rewetting. Results indicated that as drought stress continued （0 30 d）, chlorophyll content significantly （P0.01） decreased from 4.470 to 1.676 mg·g-1 and after 30 d treatment remained stable. CAT and SOD increased significantly （P0.01） as drought stress increased （0 30 d）, and after 30 d treatment maintained high levels. MDA levels were highest when 40 d treatment. After rewetting for 5 d, chlorophyll and CAT remained unchanged, whereas SOD and MDA decreased significantly （P0.01） when 5 d rewetting. This indicated that a self-repair mechanism in the leaf cell membrane of bamboo was strong, and therefore, Chimonobambusa marmorea f. variegata was a drought-tolerant plant.