【摘要】 为筛选适应退化地生长的杉木无性系 ,通过N素胁迫进行N素高效基因型杉木无性系的选择研究 ,结果表明 :不同杉木无性系的N素利用效率存在差异。随N素胁迫加剧 ,杉木无性系NR活力及光饱和点下降 ,CO2 补偿点增加 ,不同杉木无性系对N素胁迫的反应日趋明显 ,根据不同无性系在胁迫条件下的反应 ,把供试无性系分成 3类 :耐N肥性强、耐N肥性弱及耐N肥性一般无性系 ,其中 16 3号和 30 1号无性系是具有较高N素利用效率的省肥高产无性系 ,在肥力较低的林地上能获得较高的产量更多还原

【Abstract】 Chinese fir is an important timber species in south China.Since the productivity of Chinese fir plantation had been seriously declining after successive planting,the sustainable management of Chinese fir plantation becomes extremely important.In order to select the clones growing fast in degraded soil,High\|nitrogen\|efficiency\|genotypes of Chinese fir clones were studied under three sorts of nitrogen stresses(glight nitrogen deficiency,medium nitrogen deficiency,heavy nitrogen deficiency)throught the physiological process analysis of Chinese fir clones.The results were as follows:there were significant differences in nitrogen utilization efficiencies among different Chinese fir clones.As the degree of nitrogen stress increased,nitrate reductase activities and light saturation points of different clones decreased,CO\-2 compensation points increased and responses of different clones to nitrogen stresses became more obvious.The tested clones may be classified into three categories:strong,weak and intermediate capacity to nitrogen stresses according to their responses to nitrogen stress.Among the tested clones,No.163 and No.301 were the High\|nitrogen\|efficiency clones that could produce high yield in the site of low nitrogen concentration and ought to be popularized for poor site.These clones have practical significance to buffer the increasingly sever soil degradation and provide a new approach to control the productivity decline for successive planting of Chinese fir.更多还原