Studies On Physiological And Cytobiological Characteristics Of Chloroplast In The Fruit Of Actinidia

One of the most attractive features most kiwifruit (Actinidia Lindl.) has is keeping green from young fruit to mature stage, even for several months after harvest. Topics whether the kiwifruit Chloroplast has photosynthetic activity and how its physiology and structure changes are theoretic field interested. So far, studies on physiological and cytobiological dynamics of pulp Chloroplast of kiwifruit are seldom reported. This thesis tries to reveal the physiological feature of pulp Chloroplast of kiwifruit as well as its relationship with cytobiological aspect. In conducting the experiments, methods of Imaging-PAM, electronic microscopy, paraffin section, fluorescence microscopy, oxygen electrode, etc. are applied to study the spatio-temporal and also the interspecific and varieties, fruit and leaflet differences in Chlorophyll fluorescence parameters, light response curve, photosynthetic pigments, fourth derivative spectra, microstructure, ultrastructure, and etc. The main results are concluded as follow:1. Spatio-temporal heterogeneity of the fruit of Actinidia in photosynthetic activity. â‘  From the longititudinal section point of view, the fluorescence parameters (Fm, F₀, Fv/Fm, Yield, NPQ, qP and ETR) of the outer pulp vary pertaining toaxile placenta during the fruit development, storage at room and low temperature. And at the same period, the fluorescence parameters (except for Fm, F₀) of axile placenta and its outer part show larger value in the distal and base than that in the middle part of kiwifruit along with fruit development and storage periods, and all the values in the middle part become zero in the later stage.â‘¡ From the transverse section point of view, the results show that the parameters of Fv/Fm, Yield, qP and ETR decrease from the outer to inner fruit. During the storage at room temperature, the parameters of Yield, qP and ETR for the axile placenta and its outer are zero, but the other AOIs have the similar variance trend to those in developing stage. â‘¢ From the periods point of view, parameters like Fv/Fm, Yield, qP and ETR tend to decrease with fruit growth and room and low temperature storage time however, their differences are not significant during cold storage.2. There are significant differences of photosynthetic activity between different species, varieties, and between leaflets and fruits. â‘  In development stage, Qingmei fruit has higher activity than Kuimi. Qinmei fruit has higher values of Fv/Fm, Yield and ETR...