5种乡土灌木对模拟干旱胁迫的生理响应

摘要

Using PEG-6000 to simulate drought stress , we determined and analyzed the 5 physiological indexes ( relative wa-ter content, relative electrical conductivity, MDA content, soluble sugar content, and proline content) of leaves of five common wild shrub species in South China , explored the change rule of various physiological indexes of different species under different intensities of drought stress , and conducted the comprehensive evaluation of the drought resistance of these species by principal component a -nalysis.The results indicated that the leaf relative water contents of all species were decreased along with the intensification of drought stress, while Maclura cochinchinensis, Syzygium buxifolium, Syzygium tephrodes, and Cassia corymbosa also maintained higher leaf relative water content under serious drought stress .The relative electrical conductivity and MDA content all increased with the extension of stress duration .The contents of proline and soluble sugar in most species somewhat increased as the stress du -ration prolonged .The principal component analysis was carried out , and the result showed that the drought resistance of 6 shrub spe-cies had the following order:Syzygium buxifolium >Syzygium tephrodes >Maclura cochinchinensis >Rosa multiflora var.cathay-ensis >Cassia corymbosa >Ficus formosana.%采用PEG－6000模拟干旱胁迫法，对华南地区常见的野生灌木穿破石、赤楠蒲桃、粉团蔷薇、台湾榕和方枝蒲桃、伞房决明（对照）的5个生理指标进行了测定分析，探讨了各物种在不同强度干旱胁迫下生理指标的变化规律，并运用主成分分析法进行抗旱性综合评价。结果表明：随着胁迫程度加剧，各物种的叶片相对含水量均有不同幅度的下降，在重度胁迫下仍保持较高含水量的物种有穿破石、赤楠蒲桃、方枝蒲桃和伞房决明；相对电导率和丙二醛含量均随胁迫时间延长而增加；大部分物种的脯氨酸含量和可溶性糖含量随着胁迫时间延长而有所增加，但以增加幅度小的抗旱性较强。6种灌木抗旱性强弱依次排序为：赤楠蒲桃＞方枝蒲桃＞穿破石＞粉团蔷薇＞伞房决明＞台湾榕，可为华南地区裸露边坡生态修复筛选优良耐旱灌木。