棉 花 学 报    Cotton Science   2007，19(4)：279-285

Study on the Senescence Characteristic in Leaves of Different Cotton Cultivars
LI Ling-li¹，FANG Wei-ping²，XIE De-yi²，MA Zong-bin¹，DU Yuan-fang³，ZHANG Dong-lin³
(1.College of Agriculture，Henan Agricultural University，Zhengzhou 450002，China；2.Cotton and Oil Crop Research Institute，Henan Academy of Agricultural Sciences，Zhengzhou 450002，China；3. Kaifeng County Cotton Production Office，Kaifeng 457100，China )

Abstract：The changing trends of physiological index in senescence leaves were studied using fifteen cotton cultivars under field condition. The results showed that SOD activity and MDA content were higher in leaf expanding stage，and then decreased，but POD activity kept stable. The MDA content and activities of SOD，POD in mid-stage cotton leaf increased gradually，and the content of chlorophyll and photosynthesis efficiency were higher. The MDA content and activities of POD in cotton leaf of later stage still increased，and SOD activity had different trend，part of the cultivars were increasing or stable and the decrease of chlorophyll content and photosynthesis efficiency in leaf was slower. SOD activity in other cultivars decreased significantly and the decrease of chlorophyll content and photosynthesis efficiency was quicker. The results of correlation analyses showed that the correlations between SOD and chlorophyll content，photosynthesis efficiency were significantly or extremely significant positive (r=0.5408^*，0.7189^**)，The correlations between SOD and MDA was extremely significant negative (r=0.8896^**). The correlations between MDA and chlorophyll content，photosynthesis efficiency were significantly or extremely significant negative（r=0.5533^*，0.8481^**）.
Key words：leaf senescence；SOD；POD；MDA；chlorophyll；photosynthesis efficiency  [Full Text，2818KB]