不同种源流苏幼苗的耐热性评价

Heat Resistance Evaluation of Different Provenances of Chionanthus retusus

以山东青州、山西运城和河南安阳3个种源地的流苏1年生实生苗为试材,比较不同种源流苏幼苗的耐热能力,设置25、30、35、40℃等温度梯度各胁迫10 d,测定热害指数、叶片含水量、游离脯氨酸质量分数、丙二醛质量摩尔浓度、超氧化物歧化酶活性等指标。结果表明:随着温度升高,3个种源流苏幼苗的热害指数、游离脯氨酸质量分数、丙二醛质量摩尔浓度和超氧化物歧化酶活性增加,叶片含水量减少,丙二醛质量摩尔浓度和超氧化物歧化酶活性在40℃胁迫后下降。河南种源的流苏幼苗经过40℃胁迫后热害指数最小,游离脯氨酸质量分数、叶片含水量和丙二醛质量摩尔浓度变化幅度最小,超氧化物歧化酶活性在不同温度胁迫中均高于山东和山西种源。应用Fuzzy方法,对不同种源高温胁迫过程中的生理生化指标进行综合评价,得到不同种源流苏幼苗耐高温能力从大到小依次为河南种源、山西种源、山东种源。

In order to study the heat resistance of different Chionanthus retusus provenances,with 1-year potted old C. retusus seedlings of Qingzhou Shandong,Yuncheng Shanxi and Anyang Henan in 25,30,35 and 40 ℃ stress for 10 d,we observed the changes of heat injury index,leaf water content,free proline content,malondialdehyde content（ MDA） and superoxide dismutas activity（ SOD） after high temperature stress,respectively. During the development of heat stress,heat injury index,free proline content,MDA and SOD were enhanced,and leaf water content was decreased in the three provenances. The MDA content and activities of SOD were increased at the beginning of stress conditions but decreased at the end of the heat stress. Compared with Shanxi and Shandong provenances,Henan provenances had the ability to maintain physiological and biochemical indexes,changed smoothly,and had greater activities of SOD. Using fuzzy synthetic evaluation of physiological and biochemical indexes,the level of heat tolerance among the three provenances was decreased in the descending order of Henan provenance,Shanxi provenance,and Shandong provenance.