Abstract: Taking the nectarine variety ‘Shuguang’ (Prunus persica var.nectariana cv. Shuguang) as test material, and by using respiration inhibitors KCN and SHAM, this paper studied the cytochrome electron transport pathway and the alternative respiration pathway in nectarine flower bud during dormancy induction under the effects of short sunlight. Both the total respiration rate (V_t) and the cytochrome electron transport pathway respiration rate (ρ’V_cyt) presented double hump-shaped variation. Short sunlight brought the first-hump of V_t and ρ’V_cyt forward and delayed the second-hump synchronously, inhibited the ρ’V_cyt, but had no significant effects on the V_t. The capacity (V_alt) and activity (ρV_alt) of alternative respiration pathway also varied in double hump-shape, and the variation was basically in synchronous. Short sunlight made the first climax of V_alt and ρV_alt advanced, but had little effects on the later period climax. The inhibition of cytochrome electron transport pathway and the enhancement of alternative respiration pathway were the important features of nectarine flower bud during dormancy induction, and according to the respective contributions of the two electron transport pathways to the total respiration rate, the cytochrome electron transport pathway was still the main pathway of electron transport, whereas the alternative respiration pathway played an auxiliary and branched role.

Key words: short sunlight, nectarine flower bud, dormancy induction, cytochrome electron transport pathway, alternative respiration pathway