美洲黑杨及其杂种F1不同生长势无性系叶片δ^13C和氮素利用效率

Foliar δ^(13)C and Nitrogen Use Efficient of Populus deltoides and the Different Growth Vigor F_1 Hybrid Clones

以美洲黑杨不同生长势的杂种F1及其亲本为研究对象,通过测定不同冠层叶片的稳定碳同位素组成和碳、氮含量,分析不同生长势美洲黑杨叶片水分利用效率和氮素利用效率之间的差异及其相互关系。结果表明:不同生长势杂种F1的δ13C值及碳、氮含量均差异显著,超亲杂种F1在每个冠层的叶片δ13C值和碳、氮含量均显著大于低亲杂种F1;美洲黑杨叶片δ13C值与氮含量呈极显著正相关(R2=0.941);叶片δ13C和碳、氮含量存在空间分布差异,树冠上层显著大于中层,下层最小;超亲杂种F1的水分利用效率(WUE)高于低亲杂种F1,但低亲杂种F1的氮素利用效率(NUE)极显著大于超亲杂种F1,WUE和NUE之间呈现显著负相关(R2=-0.652),说明美洲黑杨叶片的水分利用效率和氮素利用效率存在一定的制约关系。

Abstract：In this paper,we measured carbon isotope composition,nitrogen content and carbon content in leaves at different canopies of Populus deltoides and their F1 hybrids to analyze the differences in the water use efficient （WUE） and nitrogen use efficient （NUE）,and their relationship over P.deltoides and the F1 hybrids with different growth vigor.The results showed that there were significant differences in the δ13C value,nitrogen content and carbon content of different growth vigor F1 hybrids.The δ13C value,nitrogen content and carbon content of better-parent F1 hybrids in each canopy layer were significantly higher than those of lower-parent F1 hybrids.The δ13C value showed a highly significant correlation with nitrogen content （R2 =0.941）.The divergency of vertical distribution of the 13C value,nitrogen content and carbon content was observed.Those parameters at the upper canopy were highest,followed by those at the middle canopy,and then by those at the lower canopy.The water use efficient of better-parent F1 hybrids was higher than that of lower-parent F1 hybrids.However,the nitrogen use efficient of better-parent F1 hybrids was lower than that of lower-parent F1 hybrids.There was a significant negative correlation between WUE and NUE （R2 =-0.652）,indicating that there were certain constraints between WUE and NUE of P.deltoides.