银杏叶片衰老过程中光合生理特性及叶绿体超微结构的变化

Changes in Photosynthesis and Uultrastructure of Chloroplasts During Leaf Senescence of Ginkgo

选取自然条件下生长的雌雄银杏植株为实验材料,测定了银杏叶片在衰老过程中部分光合生理指标及叶绿体超微结构的变化。检测结果表明:银杏叶片在衰老过程中净光合速率、叶绿素含量均呈下降趋势,SOD、CAT、APX活性均先上升后下降,MDA含量则一直呈现上升趋势。叶片衰老过程中叶绿体类囊体膜片层逐渐松散,直至膜结构逐渐解体,叶绿体内油脂颗粒增大增多,最终解体。雌雄银杏植株在各项生理指标上差异不显著。

Ginkgo （male and female） was selected to measure the changes in some photosynthetic characteristics and uhrastructure of chloroplasts during natural senescence of its leaves. The results showed thar net photosynthetic rate and chlorophyll （Chl） content decreased during leaf senescence, while the activities of SOD, CAT and APX increased at first and then decreased, which resulted in the accumulation of MDA. In chloroplasts thylakoid membranes became loose gradually, whereas the number and size of osmiophilic granule increased till the chloroplasts disappeared. There were no variations between male and female in their physiological indexes.