9种绿化树种幼苗抗旱性评价

随着城市水资源短缺,干旱问题日益严重,研究不同绿化树种的抗旱能力,可为其在不同立地条件下栽培和应用提供理论依据,对园林绿化具有重要的意义。以2年生实生苗为试验材料,在干旱胁迫处理一定时间后,测定生物量、净光合速率、丙二醛等15项生长生理指标,通过综合抗旱系数评价、隶属函数法和聚类分析对9种绿化树种进行抗旱性综合评价。干旱胁迫对9种绿化苗木生长、生理、生化特性有显著影响。水分亏缺导致其生长受到抑制,抗氧化酶活性及渗透调节物质含量明显升高(P<0.05)。3种综合方法得到的评价结果基本一致。9个树种分为2个类群,其中一类群为抗旱树种包含冬青卫矛和杜仲,另一个类群包含弱抗旱树种女贞、木槿、红花玉兰,以及干旱敏感树种玉兰、栾树、连翘和楸树。9种绿化树种的抗旱性由高到低依次为：冬青卫矛>杜仲>女贞>木槿>红花玉兰>玉兰>栾树>连翘>楸树。

Evaluation on the Drought Resistance of Seedlings of Nine Greening Tree Species

With the increasing shortage of urban water resources, the problem of drought is becoming more and more serious. To study the drought resistance of different greening tree species can provide a theoretical basis for their cultivation and application under different site conditions, and is of great significance to landscaping. Two-year-old seedlings were used as test materials. After a certain period of drought stress treatment, 15 growth physiological indicators, such as biomass, net photosynthetic rate, and malondialdehyde and etc., were measured. The drought resistance of 9 greening tree species was evaluated by comprehensive drought resistance coefficient evaluation, membership function method and cluster analysis. The results showed that drought stress had significant effects on the growth, physiological and biochemical characteristics of the 9 greening tree species. Water deficit could lead to the inhibition on the seedling growth, and the significant increase in the activity of antioxidant enzymes and the content of osmotic regulators (P<0.05). The evaluation results obtained by the three comprehensive methods were basically the same. Based on the results, the 9 tree species could be divided into two groups: one was drought-resistant tree species including Euonymus japonicus and Eucommia ulmoides, while the other one included weak drought-resistant tree species like Ligustrum lucidum, Hibiscus syriacus and Magnolia wufengensis, and drought-sensitive tree species such as Magnolia denudata, Koelreuteria paniculata, Forsythia suspensa and Catalpa bungei. The drought resistance of the 9 greening tree species followed the order of Euonymus japonicus > Eucommia ulmoides > Ligustrum lucidum > Hibiscus syriacus > Magnolia wufengensis > Magnolia denudata > Koelreuteria paniculata > Forsythia suspensa > Catalpa bungei.