大叶榉‘恨天高’对干旱胁迫的生理响应及抗旱性评价

Physiological Responses of Zelkova schneideriana ‘Hentiangao' to Different Drought Stresses During Seedling Stage and Its Evaluation of Drought Resistance

以大叶榉新品种‘恨天高’及普通大叶榉的幼苗为供试材料,采用盆栽控水人工模拟轻度、中度和重度干旱胁迫环境的方法,研究了供试材料对不同程度干旱胁迫的生理响应,筛选出了适合评价大叶榉的抗旱性生理指标,并结合隶属函数值对供试材料的抗旱性进行了综合评价。结果表明:(1)随着干旱胁迫程度的加剧,2种供试材料的Rec、MDA含量、WSD和Pro含量呈持续上升趋势,2种供试材料的POD活性、SOD活性和Chl含量随着干旱胁迫程度的加深,呈现先上升后下降的"抛物线"趋势;(2)‘恨天高’其SS含量随着干旱胁迫的加剧而逐渐升高,但普通大叶榉其SS含量呈先上升后下降的趋势;(3)Rec、MDA、WSD、Pro和POD这5个生理指标的含量变化与大叶榉的抗旱性密切相关,可以作为大叶榉抗旱性评价指标;通过对大叶榉的8项抗旱生理指标的隶属函数值进行计算,以及与主成分分析结果对各指标进行合成的综合指数表明‘恨天高’(0.58)的抗旱性稍强于普通大叶榉(0.56);(4)‘恨天高’其抗旱能力与侧柏等景观绿化树种相当,从抗旱性来看符合城市景观绿化及高速公路绿化的应用要求。

To examine the physiological responses of Z.schneideriana seedlings to drought stress and to screen out the physiological indexes of drought resistance,apot water control test was conducted.The drought resistance was also evaluated based on the membership function values.Two materials（Z.schneiderana ‘Hentiangao＇and common Z.schneiderianagrafted seedlings）were studied under three water conditions：light drought（LD）,moderate drought（MD）and severe drought（SD）.The results showed that with the increase of drought stress,the contents of the relative electric conductivity（Rec）,malondialdehyde（MDA）,water saturation deficit（WSD）and free proline（Pro）of the two testing materials were increased.And their peroxidase（POD）activity,superoxide dismutase（SOD）activity and chlorophyll（Chl）contents also changed with the increasing drought stress,as a＇parabola＇trend.The SS contents increased with the increase of drought stress for Z.schneideriana ‘Hentiangao＇,but increased first and then decreased for Z.schneiderian.Principal component analysis based on 8 drought stress indexes hinted that Rec,MDA,WSD,Pro and POD had the close relationships with the drought resistance of Z.schneideriana,and could be used to evaluate its drought resistance.The calculated membership function values of the 8 physiological indexes and the comprehensive index from the principal component analysis indicted that the drought resistance of‘Hentiangao＇（0.58）is stronger than the common Z.schneideriana＇s（0.56）.Considering the drought resistance of ‘Hentiangao＇is match with oriental arborvitae,it can meet the application requirements of urban landscape and highway greening from the point of drought resistance.