干旱胁迫对日本落叶松生理指标的影响

利用盆栽和持续干旱处理及复水后对日本落叶松生长的影响,研究日本落叶松针叶的水饱和亏(WS,D)、相对电导率(E)、丙二醛(MDA)质量摩尔浓度、叶绿素质量分数、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)酶活性、脯氨酸质量分数和可溶性蛋白质量浓度等抗旱相关生理指标的变化规律。结果表明:随着干旱胁迫程度的增加,水饱和亏、相对电导率、丙二醛质量摩尔浓度、脯氨酸质量分数和可溶性蛋白质量浓度显著上升,其中水饱和亏和相对电导率呈梯度上升趋势,可溶性蛋白质量浓度第6天达到峰值,丙二醛质量摩尔浓度和脯氨酸质量分数在第9天时达到峰值。超氧化物歧化酶、过氧化物酶活性呈上升趋势,超氧化物歧化酶活性第12天达峰值,过氧化物酶活性第9天达峰值。叶绿素a和叶绿素(a+b)质量分数呈先上升后下降趋势,都在第9天达到峰值,第12天出现下降,低于对照。叶绿素b质量分数呈微弱的下降趋势,w(叶绿素a)∶w(叶绿素b)呈上升趋势,第9天达峰值。叶绿素(a+b)质量分数变化主要是由叶绿素a质量分数变化引起的。过氧化氢酶酶活性呈先上升后下降趋势,第6天达峰值,9 d后开始下降且低于对照。用主成分分析法从指标中共提取了两个因子,累计贡献率为91.267%,因子1反映了日本落叶松针叶保水能力、抗氧化酶活性、质膜稳定性和渗透调节物对抗旱性起支配作用,因子2反映叶绿素质量分数对抗旱性起支配作用。通过灰色关联度分析,日本落叶松存活率与各指标变化幅度的关联度从大到小次序为w(叶绿素a)∶w(叶绿素b)、超氧化物歧化酶、丙二醛质量摩尔浓度、过氧化物酶、水饱和亏、脯氨酸、相对电导率、叶绿素b、叶绿素a、叶绿素(a+b)、过氧化氢酶。综合以上结果,把水饱和亏、电导率、脯氨酸和丙二醛质量摩尔浓度作为日本落叶松抗旱的有效指标。

Effects of Drought Stress on Physiological Indices of Japanese Larch

A pot experiment was conducted to investigate the effects of continuously drought stress on physiological indexes inclu -ding water saturation deficit (WSD), relative conductivity, malondialdehyde (MDA), Chlorophyll, super oxide dismutase SOD, peroxidase POD), catalase (CAT), proline (Pro) and soluble protein (SP) of Japanese larch.With the increase of the degree of drought stress , WSD, RC, MDA content, Pro content and SP content were increased significantly , WSD and RC was gradient upward trend , the content of SP reached the peak on the 6th day, the contents of MDA and Pro reached its peak on the 9 th day.The activities of SOD and POD was increased with a rising trend , and that of SOD reached the peak on the 12 th day and the 9 th day, respectively.The contents of chlorophyll a and chlorophyll (a+b) in-creased firstly and both reached the peak on the 9 th day, and decreased on the 12 th day, lower than that of CK .The con-tents of chlorophyll b showed a slight decrease trend , and chlorophyll ( a/b) showed a rising trend , and reached a peak on the 9 th day.The contents of chlorophyll (a+b) were mainly caused by the change of chlorophyll a content .The activity of CAT increased firstly reached the peak on the 6 th day, and decreased to CK after 9 d.From the physiological indexes with principal component analysis method , two factors were extracted with the cumulative contribution rate of 91.267%.Factor 1 reflected the Japanese Larch needles holding water ability , anti-oxidase activity and stability of plasma membrane and os-motic adjustment against drought control function , and Factor 2 reflected the leaf chlorophyll content against drought control function.The grey correlative degree of survival rate with other indexes was in the descending rank of Chl (a/b), SOD, MDA, POD, WSD, Pro, RC, Chl b, Chl a, Chl(a+b), and CAT.Therefore, WSD, Chl content, the activities of SOD and POD, and MDA can be used as effective indicators for drought resistance identification .