关键词: 苹果, 新梢部位, 13C同化物, 运输, 分配

Abstract: The 5-year-old apple trees（Tianhong 2/SH₄₀/Malus robusta Rehd.）were divided into three parts（the upper part，the middle part and the lower part），and those three parts（new shoot）were labeled with ¹³C to study about the fate of ¹³C-assimilates in plant. The results showed that the self-retention of the upper new shoot was the highest（91.00%），that of the middle new shoot was in the second place（79.34%），that of the lower new shoot was the lowest（67.39%）. The supply capacity of those three parts to other organs was manifested as the lower part > the middle part > the upper part. The distribution of root was very obvious，manifested as the lower part > the middle part > the upper part. More than 50% ¹³C-assimilates was allocated to aboveground in the trees that were labeled upper new shoot and middle new shoot，were 87.42% and 59.79%，respectively，only 12.58% and 40.21% were transported to root，mainly transported to above-ground. The distribution of ¹³C-assimilates in root was labeled lower parts plants reached 75.53%，mainly transported to underground（root）.

Key words: apple, different parts of new shoot, 13C-assimilate, transport, distribution