Abstract: Different plumpness buds were used to study the distribution and utilization of ¹³C and ¹⁵N
using two-year-old potted Gala apple trees（Malus × domestica/Malus micromalus Makino）as materials
under high N-level conditions. The results showed that the distribution ratios of ¹³C in leaves during the
shoots early vigorous growing period ranked in the following order：Plumpless bud tree > secondary bud
tree > plump bud tree，but the rank was plumpless bud tree < secondary bud tree < plump bud tree in
roots at the same period. The ranks were opposite in leaves and roots of the distribution ratios of ¹³C at the
vigorous growing period. The ¹³C distribution ratio in roots of plump bud tree was lower than that of
secondary bud tree and plumpless bud tree at the slow growth period. The distribution ratios of ¹⁵N in
leaves of plump bud，secondary bud and plumpless bud increased，and reached the highest at the slow
growth period，which were 55.67%，52.45% and 51.54% respectively. The ¹⁵N distribution ratios in roots
decreased significantly with the process of growth. However，the ¹⁵N distribution ratio in roots of
plumpless bud tree was the highest，followed with secondary bud tree and plump bud tree at the early
vigorous growing period and vigorous growing period. There was no significant difference at the slow
growth period. The utilization ratio of the N fertilizer and ¹³C fixed capacity were improved gradually with
the growth and development of the trees. Different plumpness buds tree can achieve results of renewal
potential.

Key words: apple, plump bud, plumpless bud, secondary bud, ¹⁵N, ¹³C, distribution；utilization