Studies On Cyanide-resistant Respiration Of Nectarine Buds During The Dormant Period

The research had been carried out in the garden and the lab of fruit tree in protected cultivation of college of horticultural science and engineering, Shandong Agricultural University from 2004 to 2006. The experimental materials were nectarine(Prunus persica var. nectariana Maxim. cv. Shuguang and Mayfire) trees. The cyanide-resistant respiration, the carbohydrate concentration, the water state, changes of electrical conductivities, changes of malondialdehyde concentration of nectarine buds were studied during different stage of dormancy. In the same time, the effects of exogenous hormones on changes in two main electron transport pathways of nectarine buds were studied elementarily. The main results were as follows:1. The bud respiration rate changed with the stage of dormancy for both cultivars. Respiration rate of buds of the controls decreased steadily before dormancy, while increased slowly from November 5th for Shuguang and October 29th for Mayfire, and then decreased sharply on December 17th at which dormancy was terminated. Cyanide (KCN) only partially inhibited respiration rate of dormant buds of nectarine during the whole period, and the trend of the buds respiration rate followed the same pattern as the control samples during the entire period. Cyanide inhibited the respiration rate of dormant nectarine buds to roughly the same degree. The effect of salicylhydroxamic acid (SHAM) on bud respiration rate varied with time. SHAM decreased bud respiration rate before dormancy and after the release of dormancy, but increased bud respiration rate during the dormancy period. SHAM increased bud respiration rate more than three times at the beginning of dormancy for all buds and the degree decreased gradually along with the dormant period until turn to decrease the respiration rate again at the end of dormancy. KCN plus SHAM had the same effect on bud respiration rate as SHAM acting alone. The time KCN plus SHAM began to increase bud respiration rate or terminated was about 7 d earlier than SHAM did, which was closely associated with the different stage of dormancy.2. The content of soluble sugar and starch in flower buds changed greatly before dormancy or after the release of dormancy, and remained steady in the middle of dormancy; the soluble sugar and starch of leaf buds changed greatly in the whole dormancy, there were several high levels. The changes of soluble sugar concentration of nectarine buds didn?ˉt follow the reverse changes of starch during the whole dormancy, while the soluble sugar raised companied starch dropped after the release of dormancy, this maybe indicate that the starch hydrolyzed and turned...