Abstract: The distribution characteristics of photosynthetic pigments and chloroplasts were investigated in outer pericarp, inner pericarp and axile placenta of kiwifruit during the fruit development period, aiming at providing scientific basis for studies on its photosynthetic mechanism and other physiological and biochemical properties. Temporal differences of the derivative absorption spectra of photosynthetic pigments and contents of chlorophylls (Chl.) were analyzed among three tissue zones of Actinididia deliciosa 'Qinmei' fruit by derivative spectrophotometry, and the distribution features of chloroplast in various pulp cells were observed in the different tissue zones of A.deliciosa 'Meiwei 84' and A. chinensis Planch 'Zhonghua 36' fruits by microscopy. The results showed that the composition of photosynthetic pigments in each tissue zone changed with kiwifruit development; The presence of Chl. and (or) chlide made the pulp green within our experimental periods; with the fruit development, Chl. a, Chl. b and Chl.(a+b) contents decreased gradually and Chl. a/b increased in the same tissue zone of 'Qinmei' kiwifruit; at the same development stage, the orders of content of Chl. a, Chl. b and Chl. (a+b) of each tissue zone of 'Qinmei' fruit were OP＞IP＞AP. Almost all the pulp cells contained chloroplasts except for mucous cells and some cells around carpellary bundle of 'Meiwei 84' and 'Zhonghua 36' fruits, and the brachysclereids of OP in 'Zhonghua 36' fruit had chloroplasts as well. The results indicate that there were significant differences in the photosynthetic pigment composition, Chl. content and Chl. a/b ratio of different tissue zones among the fruit development stages, and chloroplast distribution were similar in the pulp cells at the different tissue zones between 'Zhonghua 36' and 'Meiwei 84' fruits.

Key words: Actinidia, fruit tissue zone, photosynthetic pigment, chloroplast