【作者】 孙方行；

【导师】 孙明高；

【作者基本信息】 山东农业大学 ， 森林培育， 2006， 硕士

【摘要】 本文以一年生紫荆(Cercis chinensis Bunge)实生苗为试验材料,对其分别进行干旱胁迫、盐分胁迫和盐旱交叉胁迫。测定胁迫下的生长、生理生化、光合等指标,旨在分析紫荆在双重胁迫与单一的盐分、干旱胁迫下指标的不同变化,进而为树木的良种选育提供一定的理论基础。本研究主要得到以下结论:对紫荆在不同胁迫下伤害等级进行划分发现:在干旱胁迫下紫荆的最大伤害等级为2,而盐分胁迫下最大伤害等级为4,表明依据伤害等级为划分标准则紫荆对盐分胁迫的敏感。在盐旱双重胁迫下处理末期有6个处理组合的胁迫伤害等级达到了4级,占处理总数的66.7%,表明盐旱交叉胁迫加重了紫荆的伤害。在干旱、盐分和盐旱交叉胁迫下紫荆叶片的膜透性均随着胁迫梯度的增加而增加。在盐旱交叉胁迫试验中,经过复水各处理的膜透性均有下降的趋势。在干旱胁迫下SOD和POD对干旱胁迫的响应具有一致性,但是SOD要滞后于CAT,表明两种酶具有不同的响应时间。盐旱交叉试验中两种酶的响应时间却又具有一致性,表明对于紫荆来说在盐旱交叉胁迫下有可能产生某种适应机制。盐分和盐旱交叉胁迫下紫荆根茎叶中Na~+含量由大到小的顺序依次为:根Na~+>茎Na~+>叶Na~+。而K~+含量并没有随着处理梯度的变化而出现有规律的变化。对紫荆净光合速率的分析可知,低浓度的盐分胁迫、轻度的干旱胁迫以及轻度的交叉胁迫在短时间内都可以增强紫荆的光合能力,这也有助于紫荆增加对胁迫的抵抗能力;重度胁迫和较长胁迫时间都抑制了紫荆的光合作用。在盐分和干旱胁迫中,短期内引起紫荆光合速率下降的主要因素是气孔限制因素,而在长期胁迫时引起光合速率下降的主要因素是非气孔限制因素。在盐旱交叉胁迫中光合速率的下降则主要是由于气孔限制引起。更多还原

【Abstract】 The potted one-year-old seedlings of Cercis chinensis Bunge were tested to study their response to salt, drought and salt-drought intercross stress. In order to analyze the differences between salt, drought stresses and salt-drought stress and provide scientific and theoretic basis for selecting and breeding for superior varieties, the growth, physiological and biochemical, photosynthesis indexes of these seedlings were measured. The test results are as the followings:Through grading the injured symptom under different stresses, it was found that the highest grade under drought was 2, but under salt stress it was 4.The result showed that seedlings of Cercis chinensis Bunge was more sensitive to salt stress than drought stress. There were 6 kinds of treatments whose grade was reached 4, and it was accounted for 66.7% of all the treatments. The result showed that salt-drought intercross stress had made more adverses effect on the seedlings of Cercis chinensis Bunge than that of salt or drought stress.The membrane conductibility was increased as the enhancement of stresses intensity. After water recovering the membrane conductibility was decreased under salt-drought intercross stresses.The dynamic of SOD and CAT are same in basically the response to drought, but SOD was lagged to CAT. It was showed that these two kinds of enzyme have different response time. But they have the same response time under salt-drought intercross stress, so it may produce adaptation mechanism under salt-drought intercross stress.The sequence of content of Na~+ were root>stem>leaf under salt and salt-drought intercross stress. The content of K~+ did not have regular changes更多还原