干旱风沙区煤炭基地12种草本植物对干旱胁迫的生理生态响应及抗旱性评价

Physiological-ecological responses of twelve herbaceous plant species under drought stress and evaluation of their drought resistance when planted in coal producting basis in arid windy and sandy areas

为筛选适宜于西北干旱风沙区煤炭基地植被恢复建设需要的草本植物,以二色补血草、蒙古冰草、沙生冰草、沙打旺、草木樨、白三叶、苜蓿、甘草、沙蒿、碱蓬、蜀葵、沙米为试验材料,采用盆栽控制土壤水分的方法,研究了土壤自然渐进干旱胁迫下12种草本植物功能性状、光合特性及抗氧化保护酶的变化,并基于主成分分析与隶属函数值相结合的方法,对其抗旱性进行综合评价。结果表明:在土壤渐进干旱胁迫过程中,12种草本植物的株高(H)、比叶面积(SLA)、叶片干物质含量(LDMC)、叶片相对含水量(LRWC)与根冠比(R/S)均受到不同程度的影响,并在胁迫14 d后影响更显著(P<0.05)。渐进干旱胁迫至21 d(土壤含水量为1.35%),12种草本植物的净光合速率(Pn)、气孔导度(Gs)与蒸腾速率(Tr)均降低;超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性、丙二醛(MDA)含量均升高;复水后,各草本植物SOD、CAT活性均降低,而MDA含量存在较大差异,其中蒙古冰草、沙生冰草、沙打旺与苜蓿的MDA含量均升高。主成分分析表明,功能性状与抗氧化保护酶等指标贡献率较大,可作为评价各草种适应干旱胁迫的重要指标。基于主成分分析与隶属函数值相结合的方法,综合评价12种草本植物的抗旱能力排序为:沙蒿>沙打旺>草木樨>蜀葵>蒙古冰草>碱蓬>白三叶>苜蓿=甘草>沙生冰草>二色补血草>沙米。

This research aimed to identify herbaceous plant species which are suitable for vegetation restoration and construction in coal producting basis in arid wind and sand areas,we studied the effects of drought stress on functional traits,photosynthetic characteristics and antioxidase activities of twelve herbaceous plant species grown in pots.The tested plant species were:Limonium bicolor,Agropyron mongolicum,Agropyron desertorum,Astragalus adsurgens,Mellilotus officinalis,Trifolium repens,Medicago sativa,Glycyrrhiza uralensis,Artemisia ordosica,Suaeda glauca,Althaea rosea,and Agriophyllum squarrosum.It was found that at low soil water content,the plant height,specific leaf area,leaf dry matter content,leaf relative water content and root:shoot ratios of all species were affected by the drought stress to some extent,and most species were significantly affected after 14 days of drought stress.Compared with the control treatment,the net photosynthetic rate,stomal conductance and transpiration rate decreased and the activities of superoxide dismutase,catalase,and malondialdehyde(MDA)concentration increased among twelve herbaceous plants after 21 days of drought stress.Re-watering after drought stress resulted in partial recovery of superoxide dismutase,and catalase activity.However,there was significant variation in the MDA content of the twelve species after re-watering,and the MDA content of A.mongolicum,A.desertorum,A.adsurgens and M.sativa displayed an upward trend.Evaluation of multiple traits by principal component analysis showed that the functional trait and antioxidase activity data could be used to evaluate the adaptation capacity of the plant species under drought stress because these traits had the largest eigenvector coefficients.The drought resistance of the twelve herbaceous plant species was then evaluated with a multivariate procedure combining principal component analysis and membership function value,and the ranking so obtained was A.ordosica>A.adsurgens>M.officinalis>A.rosea>A.mongolicum>S.glauca>T.repens>M.sativa=G.uralensis>A.desertorum>L.bicolor>A.squarrosum.