Abstract: In this paper, chlorocholine chloride was sprayed on 7-year old Myrica rubra cv. Dongkui after 1-week simulated acid rain (pH 3.5) stress, aimed to study the alleviative effects of chlorocholine chloride on the acid rain stress to the floral bud formation and differentiation of the plant. Spraying low concentration chlorocholine chloride promoted the leaf superoxidase (SOD), peroxidase (POD), and catalase (CAT) activities, alleviated the peroxidation of membrane lipid, decreased the accumulation of malondialdehyde (MDA) and the relative permeability of cell membrane, and thus, enhanced the leaf resistance to acid rain. Meanwhile, chlorocholine chloride eased the degradation of chlorophyll and carotenoid, increased the transpiration, stomatal conductance, and net photosynthetic rate remarkably, and accordingly, increased the leaf soluble protein and sugar contents and promoted the floral bud differentiation and blooming and fruit-setting rates.

Key words: Soil hydrolase, Kinetics, Properties