摘要
以青藏高原6种植物:红花岩黄芪(Hedysarum multijugum Maxim.)、西北沼委陵菜(Comarum salesovianum(Steph.)Asch.et Graebn.)、鲜黄小檗(Berberis diaphana Maxim.)、鲜卑花(Sibiraea laevigata(Linn.)Maxim.)、树锦鸡儿(Caragana arborescens(Amm.)Lam.)、砂生槐(Sophora moorcroftiana(Benth.)Baker)为试材进行干旱胁迫模拟盆栽试验,通过对比6种植物叶片中丙二醛(MDA)、脯氨酸、可溶性蛋白质、叶绿素、可溶性糖、淀粉含量的变化,对供选植物进行抗旱性能分析与评价,为在青藏高原地区筛选优良耐旱植物提供参考依据。设置土壤含水量占田间持水量80%以上为正常水平,50%—70%为轻度干旱,30%—50%为中度干旱,低于30%为重度干旱。研究表明,6种供试植物叶片MDA含量逐渐升高,当土壤含水量占田间持水量12%左右时达到最大值,树锦鸡儿的增幅较另5种苗木最小,而峰值最大。脯氨酸含量都呈增加趋势,其中砂生槐最高,为9981.67mg/g,峰值与对照值相比,砂生槐增加最多为37.43倍,鲜卑花最小为0.49倍。苗木叶片中可溶性蛋白质含量总体表现出现增大后减小的规律,且所有测定值都高于正常水分条件下的含量。6种苗木的叶绿素含量在干旱胁迫下总体呈现先降低再升高最后再降低的趋势,24 d时均低于对照值,下降最多的为西北沼委陵菜(15.43 mg/g)。由于干旱下苗木的光合产物转化受抑,以淀粉形式的累积量减少,所以6种苗木的可溶性糖含量呈上升趋势,而淀粉含量呈下降趋势,通过积累可溶性糖以提高细胞的渗透调节能力。砂生槐、树锦鸡儿的可溶性糖含量增幅与淀粉含量的减少明显高于其余苗木,使其在较低叶水势下仍保持较高的细胞膨压,以减缓水分胁迫的不利影响。主成分分析表明,6种苗木抗旱性由强到弱依次为:树锦鸡儿、红花岩黄芪、砂生槐、鲜黄小檗、鲜卑花、西北沼委陵菜。
During adaptation to the environment,plants can gradually develop drought resistance via a process of natural selection. Plants are often under water stress in the cold and dry environmental conditions on the Tibetan Plateau,and these conditions can directly affect various physiological activities. The aim of this study was to analyze and evaluate the drought resistance of selected plants from the Tibetan Plateau,and to provide a reference for selecting drought-tolerant plants. We collected six species of plants from the Tibetan Plateau, Hedysarum multijugum Maxim,Comarum salesovianum（ Steph.）Asch. et Graebn.,Berberis diaphana Maxim.,Sibiraea laevigata（ Linn.） Maxim.,Caragana arborescens（ Amm.） Lam.and Sophora moorcroftiana Benth Baker. To protect themselves against drought and low-temperature stress,plants have evolved efficient antioxidant systems to scavenge reactive oxygen species. We evaluated changes in the amounts of malondialdehyde（ MDA）,proline,soluble protein,chlorophyll,soluble sugars,and starch in leaves of these species subjected to increasingly severe drought conditions in a pot experiment. The soil moisture was greater than 80% of field capacity for the normal level,50% —70% for mild drought,30% —50% for moderate drought,and less than 30% for severe drought. In all six plant species,the MDA content increased slowly from day 0 to day 12 of the drought treatment,and then increased significantly after day 16 to reach a peak when the soil water content was approximately 12%. Caragana arborescens showed the smallest increase in MDA content under drought,but had the highest MDA content（ 4. 72 mmol /g）among the six plant species. The proline content increased in all six species under drought,and there were significant differences among species in the amount of proline accumulated. The largest increase in proline content was in S.moorcroftiana（ peak value,9981. 67 mg /g, 37. 43 times that in CK）,and the smallest was in S. laevigata（ peak value was 0. 49 times that in CK）. Th
出处
《生态学报》
CAS
CSCD
北大核心
2014年第13期3558-3567,共10页
Acta Ecologica Sinica
基金
林业公益性行业科研专项(200904033)
科学技术部农业科技成果转化资金项目(2011GB24320010)
关键词
干旱胁迫
青藏高原
生理指标
主成分分析
drought stress,Tibetan Plateau,physiological indexes,principal component analysis
