Abstract: In order to screen suitable materials for studying the molecular mechanism of ‘Huangjinya’, the spring shoots of ‘Huangjinya’ were treated with double shading (average light intensity of 10βklx), single shading (average light intensity of 40βklx) and non-shading. And three new shoots, light green (H_1W), light yellow (H_4W) and bright yellow (Hs), were obtained. At the same time, the second leaf under bud was selected as material with ‘Fudingdabai’ green shoot (CK_f) as control. The content of hydrogen peroxide, oxygen-and histochemical localization, antioxidant enzyme activity, photosynthetic response curve, chlorophyll fluorescence and other physiological indicators of leaves were measured and the structure of chloroplast membrane system was observed. The results show that The H₂O₂, O₂^- contents, Fv/Fm value and chloroplast membrane system of light yellow leaf H_4W were similar to those of light green leaf H_1W, which were in a stress-free state. At the same time, the photosynthetic and physiological characteristics of light yellow leaf H_4W and bright yellow leaf Hs were similar. There were no significant differences in chlorophyll fluorescence parameters and photosynthetic indexes such as ΦPSⅡ, qP, light saturation point and light compensation point, and the characteristics of light response curve were similar. Because of the above physiological characteristics of light yellow leaf H_4W, it could be used as the research material to explore the molecular mechanism of yellowing of golden bud tea varieties.

Key words: Camellia sinensis cv. Huangjinya, photooxidation stress, light-intensity, chlorotic material