水肥耦合效应对楸树苗木叶片δ^(13)C的影响  

Coupling Effects of Soil Water and Fertilizer Application on Leaf δ^(13)C of Catalpa bungei Seedlings

作　　者：邱权[1] 李吉跃[1] 王军辉[2] 何茜[1] 苏艳[1] 马建伟 吴俊文[1] 白晶晶[1] 

机构地区：[1]华南农业大学林学与风景园林学院,广州510642 [2]中国林业科学研究院林业研究所国家林业局林木培育重点实验室,北京100091 [3]甘肃省小陇山林业科学研究所,甘肃天水741022

出　　处：《西北植物学报》2015年第11期2290-2298,共9页Acta Botanica Boreali-Occidentalia Sinica

基　　金："十二五"农村领域国家科技计划课题(2012BAD21B03;2012BAD21B0304);教育部博士点基金(20124404120008)

摘　　要：以楸树(Catalpa bungei)无性系004-1苗木为研究对象,采用三因素五水平二次回归通用旋转组合设计进行盆栽试验,通过测定6、7和8月份20个处理楸树苗木叶片碳同位素组成δ^(13)C、总氮含量和总磷含量,建立数学模型,分析土壤水分、施氮量和施磷量的主因子效应、单因素效应及其耦合效应对叶片δ^(13)C的影响,以及叶片碳同位素组成δ^(13)C与其总氮含量和总磷含量的关系。结果表明:(1)楸树苗木叶片δ^(13)C存在明显的月动态变化特征,总体上呈现出6月份高于7、8月份的趋势,20个处理苗木叶片δ^(13)C平均值(6~8月)变化范围介于-29.12‰^-26.60‰之间;(2)土壤水分对叶片δ^(13)C有显著负效应,施氮量对叶片δ^(13)C有显著正效应,并且施氮量主效应大于土壤水分主效应,但施磷量对叶片δ^(13)C无显著主效应;单因素效应分析表明,楸树苗木叶片δ^(13)C随土壤水分或施氮量的增加均呈先增加后减小的"抛物线型"关系;土壤水分×施N量对楸树苗木叶片δ^(13)C有显著耦合负效应,土壤水分和施氮量耦合效应图表明,叶片δ^(13)C随土壤水分降低、施氮量增加而逐渐增加;(3)6月、7月和8月份楸树苗木叶片δ^(13)C与其叶片总氮含量均呈显著正相关关系(P<0.05;n=100),但叶片δ^(13)C与总磷含量无显著相关关系(P>0.05;n=100)。研究认为,楸树苗木叶片碳同位素组成δ^(13)C随生长期表现出动态变化特征,它受到土壤水分、水氮耦合的显著负向影响,以及施氮量的显著正向影响,可以通过合理水肥配施措施大幅提高楸树苗木δ^(13)C。By using rotatable central composite design（RCCD） for a pot experiment with three factors,five levels,twenty runs,we determined leaf δ^13C,nitrogen content（LN） and phosphorus content（LP） of Catal- pa bungei seedling（clone 004-1） under different treatments in June and July. Mathematical model was es- tablished for analysis of main factor effects,monofactor effects, and the combined effects of W（soil water）, N（nitrogen） and P（phosphorus） on leaf δ^13C,also,LN and LP were correlated with leaf δ^13C. The results showed that： （1）monthly dynamic of leaf δ^13C of C. bungei seedlings was obviously found in the study,and the average leaf δ^13C（average measurements in June, July and August） of 20 treatments ranges from --29.12‰ to --26.60‰. （2）W had a significantly negative efirect on leaf δ^13C, and N had a significantly positive effect on leaf δ^13C, with a size sequence of N〉W, whereas P had no obvious effect on leaf δ^13C. Monofactor effects analysis results showed that the changes of leaf δ^13C with W or N increasing both showed a parabolic trend： first increasing and then decreasing. Interaction of W X N had obvious effect on leaf δ^13C of C. bungei seedling in July,but no significant effect on leaf δ^13C of C. bungei seedling in August. Moreover,the response surface on interaction between W and N indicated that leaf δ^13C increased gradually with W decreasing and N increasing. （3） Leaf δ^13C showed a significantly positive correlation with LN in July and August（P〈0.01;n=100）, whereas the correlation between leaf δ^13C and LP was not significant （P〉0.05 n= 100）. In general, leaf δ^13C of C. bungei seedling was observed to change dynamically along with the growth period,and be negatively affected by W and W）〈 N and positively affected by N, thus, it could be promoted by the rational method of irrigation and fertilizer application.

关 键 词：水肥耦合效应 碳同位素组成δ^13 C 叶片养分 数学模型 楸树 

分 类 号：Q945.79[生物学—植物学]