Study On The Senescence Character Of Old Ginkgo Biloba And Old Sophora Japonica

Old tree is became aging gradually with the passage of time.As old trees aging, nutrition,water,hormone and enzyme show obvious changes.Physiological structure,biochemical index and molecular marker were compared between young trees and old trees in this experiment,in order to select indicator to characterized aging.①Leaf ultrastructure of Ginkgo biloba and Sophora japonica were observed through light microscopy,the results showed that cells of Ginkgo biloba leaf were regular shape,shape of chloroplast was spindle,the arrangement of leaf cells became loose and the quantity of chloroplast decreased with the passage of time.Cells of Sophorajaponica leaf were ellipse,shape of chloroplast was ellipse,the arrangement of centennial Sophora japonica leaf cells were more loose than contrast.②Leaves of Ginkgo biloba and Sophora japonica were collected in different seasons to observe through electron microscopy.The results showed that quantity and volume of starch of old Ginkgo biloba and Sophora japonica increased with time, compared control.The change of quantity and definition of chloroplast of old and control trees showed declined trend.The quantity and volume of starch of old trees were more than contrast and proportional to the age in the same time.③The change of chlorophyll content of old and contrast trees were determined, the results showed that the chlorophyll content of old and contrast trees reached the highest point in May,the chlorophyll content of contrast was more than old tree in every month.④The photosynthetic activity of old and young trees were studied,through determined chlorophyll fluorescence.Fluorescence kinetic parameters showed that photosynthetic rate was higher than old trees,the value of Fv/Fm showed that photosynthetic rate of old trees decreased,degree was proportional to the age,the value of qP showed that photosynthetic activity of old trees was lower than contrsat, degree was inversely proportional to the age,the value of qN showed that old Ginkgo biloba were more adaptive to intense light.⑤Transmittance of THz and Moisture evaporation was inversely proportional to the age,through THz-TDS.⑥ABA and IAA were determined through Gas - MS.The results showed that the content of ABA was proportional to the age in same month,the content of ABA of the same tree was proportional to the time,the content of IAA was inversely proportional to the age in same month.⑦rbcL gene was choose to be sequences alignment.The results showed that the difference of bases mutant between different trees were obvious,because this,the rbcL gene could be a marker to characterize Ginkgo biloba aging.The difference of bases mutant between old and young Sophora japonica were less evident,partly because the age distance between old and young was small.