摘要
采用干旱胁迫处理不同生态型沙地云杉幼苗,对其主干高生长、丙二醛(MDA)、脯氨酸和叶绿素含量进行了测定。结果表明,沙地云杉幼苗高生长明显受到干旱胁迫的抑制,绿果型沙地云杉在水分条件良好的情况下,高生长迅速,明显高于紫果型沙地云杉。随着干旱胁迫强度的增强,其高生长受抑制的程度高于紫果型沙地云杉。红果型沙地云杉处于二者之间。同时干旱胁迫也影响沙地云杉生长进程,使得其封顶时间提前一个多月,MDA含量无论在叶还是根中呈上升趋势,只是在土壤含水量在10％左右出现轻度胁迫时略有下降;叶片中MDA含量明显高于根中;从不同生态型来看,紫果型沙地云杉体内MDA含量高,绿果型低且具有较大的变化幅度。脯氨酸含量随干旱胁迫强度增加而增加;绿果型沙地云杉根部脯氨酸含量在处理4之前高于另外两种生态型,叶绿素的变化规律,紫果型和红果型沙地云杉基本相同,只是红果型含量略微低于紫果型,其叶绿素a、叶绿素b和总叶绿素含量都是开始逐渐升高;随着胁迫强度增加,叶绿素含量下降;绿果型沙地云杉叶绿素含量总体上都呈下降趋势,只有叶绿素b含量在胁迫初期有所增加。从叶绿素a/b值出现下降趋势,但不同生态型表现不一样。绿果型沙地云杉由最高下降到最低,紫果型沙地云杉下降幅度较小,红果型介于二者之间。表明不同?
The seedlings of different Picea mongolica ecotypes were treated with drought stress, and their height growth, MDA, proline, and chlorophyll content were investigated. The results showed that the height growth was obvi-ously reduced by drought stress. With sufficient water supply, the height growth of f. viridis W. D. Xu f. nov Picea mongolica was rapid and obviously better than that of f. purpurea W. D. Xu f. nov Picea mongolica, but was obviously reduced by intense drought stress. Furthermore, drought stress shortened the annual growth period of Picea mongolica, and made its terminal hud formation more than one month earlier, increased in both needles and roots, but was higher in needle than in root. The MDA content was higher in Picea mongolica than in f. viridis W. D. Xu f. nov Piburcea mongolica, and the proline content in needles was increased with increasing drought stress, hut in roots, the proline content was higher in f. viridis W. D. Xu f. nov Picea mongolica than in f. purpurea W. D. Xu f. nov Picea rnongolica and f. rubra W. D. Xu f. nov Picea mongolica. The latter 2 forms showed a similar trend in chlorophyll content. Their chlorophyll a, chlorophyll b and total chlorophyll contents increased at the beginning of drought treatment, and then decreased with increasing drought stress. The chlorophyll content of f. viridis W. D. Xu f. nov Picea mongolica decreased with drought stress. The ratio of chlorophyll a / b decreased from maximum to minimum in f. viridis W. D. Xu f. nov Picea mon-golica,but decreased in a relative small extent in f. purpurea W. D. Xu f. nov. It's proved that f. purpurea W. D. Xu f. nov Picea mongolica had a larger drought-resistance capacity than f. viridis W. D. Xu f. nov, and f. rubra W. D. Xu f. nov was a typical transitional ecotype from f. purpurea W. D. Xu f. nov to f. viridis W. D. Xu f. nov.
出处
《应用生态学报》
CAS
CSCD
2003年第9期1446-1450,共5页
Chinese Journal of Applied Ecology
基金
国家自然科学基金资助项目(39900019
30070129)
中国博士后科学基金资助项目
关键词
沙地云杉
生态型
干旱胁迫
生理生态响应
Picea mongolica, Ecotype, Drought stress, Eco-physiological response.
