Changes Of Chloroplast Light-energy Conversion Characteristics On Leaves Of Gingko

This thesis studied the light-energy conversion characteristics,protein content in chloroplast at initial stages and the light-energy conversion characteristics,chloroplast ultra-structure during the process of senescence on cell level,using male and female Gingko as materials,exploring photosynthesis rule taking reasonable planting measurement and management,increasing productivity and rational using of Ginkgo resource.The results showed as follows:1.The light-energy conversion characteristics of Gingko chloroplast in nature condition were investigated.The results showed that:photosynthetic rate and chlorophyll content of Gingko increased as leaf spreading.The content of ATP increased with the activity of photophosphorylation,keeping low content after germination,and having the maximum content of ATP after 65 days as leaves growing; Mg²⁺,Ca²⁺-ATPase activity changed from high level to low after germination,and reached the lowest level after 50 days as leaves growing,then its activity ascended sluggishly.The results also showed that all light-energy conversion characteristics had the similar change in male and female.2.The light-energy conversion characteristics of Gingko chloroplast in nature condition were investigated.The results showed that:in the beginning of senescence, photosynthetic rate maintained in high level,and gradually reduced till leaves fell off; photophosphorylation activity and ATP content held steadily at all times,it went up to maximum in the middle of September;ATPase activity of chloroplast in Gingko took on ascending current in the process of senescence;O₂ evolution and electron transfer activity of chloroplast in Gingko took on descending current in the process of senescence,but it had a maximum in September.3.During the process of senescence,Gingko chloroplast in nature condition disintegrated,the number of chloroplast reduced incessantly,finally resulted in the descendent of photosynthetic rate,it always showed that photosynthesis function of Gingko had connection not only with inner structure of chloroplast but also with the number of chloroplast.4.In nature condition,male and female Gingko can saw several obvious protein bands as 17KD,22KD,32KD,47KD,55KD,60KD et al,especially 55KD,we can saw 10KD band in male Gingko.Fluorescence emission apex of male and female Gingko occurred at 638nm and 685nm.