关键词: 苹果, 秋梢, ¹³C, ¹⁵N, 吸收, 利用, 分配

Abstract: Experiments designed to test the effectiveness of autumn shoots on physiological activity and characteristics of distribution and utilization of ¹³C and ¹⁵N on 4-year-old apple tree（Fuji/SH₁/ Malus robusta Rehd.）. Results showed that continued pinching the autumn shoots，IAA content of leaves significantly decreased and ABA content significantly increased，fine root’s growth decreased to 51.68%，and the activity decreased to 70.10% of the control. ¹³C absorption and utilization of ¹⁵N decreased to 41.01% and 32.22% of the control. ¹³C and ¹⁵N absorption and partition ratio of leaves and new shoots significantly decreased. ¹³C and ¹⁵N partition ratio of stem xylem were significantly increased to 3.59 and 3.86 times，while the ¹³C and ¹⁵N absorption were only 1.45 and 1.26 times respectively. With no significantly differences of ¹³C partition ratio and significantly increased ¹⁵N partition ratio of main root xylem，the absorption of ¹³C and ¹⁵N were significantly decreased to 47.40% and 58.44% of the control.

Key words: apple, autumn shoot, ¹³C, ¹⁵N, absorption, utilization, distribution