‘金焰’绣线菊幼苗水分胁迫耐性评价方法研究

Simple Method to Evaluate the Drought Tolerance of Spiraea×bumalda ‘Goldflame’ Seedlings

以‘金焰’绣线菊1 a生幼苗为试材,通过确定植株形态萎蔫指数及测定叶片相对含水量、可溶性蛋白(SP)、可溶性糖(SS)、脯氨酸(Pro)、丙二醛(MDA)等含量及超氧化物歧化酶(SOD)等活性,对‘金焰’绣线菊的耐旱性评价方法进行了探讨。结果表明:‘金焰’绣线菊幼苗在自然失水和PEG渗透胁迫下的形态变化差别不明显,根据植株在失水胁迫下的形态特征,将植株萎蔫指数划分为5级。在自然失水胁迫下,随着胁迫时间的延长,叶片相对含水量持续下降,SP、MDA和Pro含量持续上升,SS含量先上升后下降再上升,SOD活性呈先上升后下降的趋势,各指标变化规律显著,可作为自然失水胁迫耐旱性评价指标;PEG渗透胁迫下,随着胁迫时间的延长,叶片相对含水量持续下降,SP、MDA含量持续上升,SS含量则在胁迫初期先上升,随后下降,最终呈上升趋势,故可作为PEG胁迫的耐旱性评价衡量指标,而Pro含量和SOD活性变化无规律,只能作为参考。

One-year seedlings of Spiraea×bumalda ‘Goldflame’ were exposed with the determination of the welting index and the measurements of the leaf relative water content,SP,SS,Pro,MDA content and the SOD activities,a simple method to evaluate the drought tolerance of Spiraea×bumalda ‘Goldflame’ was discussed.The results showed that differences of the morphological change of Spiraea×bumalda ‘Goldflame’ seedlings were not obvious under the two different water stress.According to the morphological feature of the plants under different water stress,the welting index was divided into 5 grades.Under the dehydrations in air,with lengthen of stress time,the leaf relative water content was persistent declined.However,the SP content,Pro content,MDA content were continued increased while the SS content showed an increase-reduce-increase tendency and the activities of SOD showed an upgrade-decline tendency.The changes of the physiological indexes were related to drought tolerance significantly,so they were the evaluation indicators for water stress tolerance of Spiraea×bumalda ‘Goldflame’ seedlings under the dehydrations in air;Under the PEG stress,with the lengthen of stress time,the leaf relative water content was persistent declined.However,the SP content,MDA content were continued increased while the SS content showed an increase-reduce-increase tendency,so they were the evaluation indicators for PEG stress tolerance of Spiraea×bumalda ‘Goldflame’ seedlings.However,the Pro content and the activities of SOD showed no tendency,so they were only the references for water tolerance evaluation.