Abstract:

The variation characteristics of photosynthetic pigments, chloroplast cytology and its photosynthetic oxygen evolution rate were investigated in outer pericarp (OP), inner pericarp (IP) and axile placenta (AP) of Actinidia deliciosa ‘Qinmei’ fruit during cold storage,obtain basic knowledge of quality keeping in process of cold storage. The results showed that the composition of photosynthetic pigments in each tissue zone changed with the time of refriferation. The presence of Chl and (or) chlide make the pulp assume green color； however with the fruit cold-stored time, Chl a, Chl b and Chl(a+b) contents decreased gradually and Chl a/b increased. At a given cold-stored stage, the orders of content of Chl a, Chl b and Chl (a+b) of each tissue zone of the fruit were OP＞IP＞AP. The chloroplasts were solid irregular sphericity under lightfield and honeycomb like under fluorescence microscope before cold storage. Some starch grains were spilled into the cytoplasm from the chloroplasts. The number and volume of the chloroplast of every tissue zone became less and smaller, starch grains hydrolyzed and chloroplasts disintegrated with cold storage. The starch grain became less significantly and remnant lamella structure was frequently found after 30 d cold storage. The photosynthetic oxygen evolution rates of each tissue zone decreased with cold storage and the orders of the rates were： OP＞IP＞AP at the same period of cold storage. It was concluded that there were differences among photosynthetic pigments, morphology structure of chloroplast and photosynthetic oxygen evolution rate in each tissue zone during cold storage.

Key words: kiwifruit, fruit tissue zone, photosynthetic pigment, chloroplast, photosynthetic oxygen evolution