不同光强与水分条件对海州常山幼苗形态与生长的影响  

Influence of light intensity and soil water content on morphological and growth traits of Clerodendrum trichotomum seedling

作　　者：胡凤琴[1] 杨文杰[1] 徐贵明[1] 王中生[1] 安树青[1] 

机构地区：[1]南京大学生命科学学院森林生态与全球变化实验室,江苏南京210093

出　　处：《南京林业大学学报（自然科学版）》2009年第5期27-31,共5页Journal of Nanjing Forestry University：Natural Sciences Edition

基　　金：国家自然科学基金面上资助项目(30570298);国家自然科学基金重点资助项目(30430570)

摘　　要：以阔叶小灌木海州常山(Clerodendrum trichotomum)为材料,比较了其幼苗的形态、生物量分配及生长对不同光照处理(全光照、20%光照和5%光照)和土壤水分(田间持水量的75%～100%、50%～75%、25%～50%)的响应。结果表明:(1)海州常山幼苗的大部分表型特征主要受光照的影响,土壤水分对其影响较小;(2)株高、茎粗、根生物量比随着光强度的增强而增加,相对生长速率和净同化速率极显著增加;茎生物量比、叶生物量比、平均叶面积比和比叶面积则随光强的增加而减小;(3)20%光照处理下,海州常山幼苗通过大幅度提高平均叶面积比以适应中度遮阴;而5%光强时,3种水分条件下幼苗平均的相对生长速率分别只有全光照与20%光照处理的8.2%和11.4%,表明深度遮阴会严重影响海州常山的生长。Clerodendrum trichotomum Thunb. is a broad-leaved understory shrub, well recognized for the ecological and economic values, such as ecological restoration and medical use. However, this species is relatively poorly characterized regarding the seedling growth in natural populations or under controlled conditions. Our study aimed to fill this gap by examining both the phenotypic and growth parameters of seedlings in response to a series of light intensity （ i. e. 100% , 20% and 5% sunlight） and soil water content （ i. e. 75%--100% , 50%--75% , 25%--50% field capacity）. The results revealed that most of seedling morphological features were more likely to be influenced by light intensity rather than soil water content. However, these phenotypic and growth parameters varied in response to light intensity. Some specifically, stem height, stem diameter, root biomass ratio, relative growth rate and net assimilation rate exhibited a positive correlation with light intensity particular for the latter two indicators, while stem biomass ratio, leaf biomass rati- o, mean leaf area ratio and specific leaf area showed tbe reverse trend. Under 2{）% of full light intensity, seedlings presented shade-tolerance through large increase of mean leaf area ratio; While the mean relative growth rate under three soil water content was extremely low under 5% of full light intensity only accounting for 8.2% and 11.4% of that under 100% and 20% of full light intensity respectively, which probably indicated seedling growth would be severely hampered by deep shade.

关 键 词：海州常山 幼苗 光照度 土壤水分 形态特征 生长特征 

分 类 号：S718[农业科学—林学]