研究不同浓度赤霉素对南林-895杨叶片、茎中可溶性糖含量的影响以及二者之间的关系.结果表明,50 mg/L GA3在促进杨树苗正常生长发育过程中,对"源"(叶)中可溶性糖的生成、转运和"库"(茎)组织器官的构建具有更好的效果.此外,对于同一浓度赤霉素处理的杨树苗,经相同的处理时间后,杨树苗"源"(叶)中可溶性糖含量始终高于"库"(茎)中相应的可溶性糖含量,且"源、库"中蔗糖含量也始终高于果糖含量.这恰好表明杨树糖转运和代谢过程中"源""库"的关系和蔗糖浓度梯度的重要性.

In this paper,growth in height,caliper,and biomass,and dynamic changes of the δ13C and δ15N value in the vegetative organs of Populus × euramericana‘Nanlin 895’cuttings were investigated in response to different concentrations of exogenous Ca2 + treatments. The experimental results showed that different concentrations of exogenous Ca2 + were able to promote the plant growth; the height,caliper,and biomass increments were all greater than the control after spraying exogenous Ca2 + ,among which the 200 mg·L -1 Ca2 + concentration exhibited the best effect. Compared with the control, the average of the height,caliper and biomass treated with 200 mg·L -1 Ca2 + increased by 14. 82% ,18. 01% ,and 19. 7% respectively. The stable isotope,δ13C and δ15N,enrichment capacity of the Populus × euramericana‘Nanlin 895’ cuttings were affected by different concentration exogenous Ca2 + to various degrees. With the Ca2 + concentration increased (0,2,20,100,200,300 mg·L -1),the δ13C and δ15N values of the leaf,stem and root presented a gradual increase at low concentrations,and then slowly declined at high concentration,with the maximum value appeared at the concentration of 200 mg·L -1 Ca2 + . The distribution of δ13 C and δ15 N value in the plant complied with the principle that the "sink" organ was more than the"source"organ. The correlation analysis showed that both the δ13C and δ15N values of"source" organ had a significantly negative correlation with the height,caliper,and the positive correlation with biomass. The δ13C, δ15N value of"sink"organ had a significantly positive correlation with the plant height,caliper,and biomass. The δ13C, δ15 N value dynamic changes of different vegetative organs reflected to a certain extent accumulation and redistribution patterns of the photoassimilates in the"source"and"sink"organs of Populus × euramericana ‘Nanlin 895’cuttings in response to exogenous Ca2 + concentration.