The Change Of Carbohydrate And The Effect Of It On The Senescence Of Maize Leaves In Source-Sink Alteration In Maize Leaves During Senescence

The variety of the content of sucrose ,total sugar and starch of the leaves and steam of maize and the activity of Superoxide dismutase and Perox dase and the content of Malondialclehyde and ChlorophII of leaves were studied inShandan9,Shandan911,Yuyu22,Yedan19,Shandan902 and Xinong11 based by removed ears and unremoved ears.The aim of this study was to show effects of removed ears on the senescence of leaves.The resules showed as following:1.Removed ears in different days showed that the activity of SOD of these six removed ears maize which were removed ears after zero days of spinning were all lower than that of the control after 20 days in which the six maize were removed ears and POD were all lower than that of the control after 20 days in which the six maize were removed ears.Removed ears in 20 days after spinning,the activity of SOD were all lower than that of the control 10 days later.Removed ears in 30 days after spinning,th activity of POD were all lower than that of control 10 days later.The content of MDA of cutting ears maize'leaves were all higher than that of unremoved ears maize. These all reflect that removed ears accelerated the senescence of leaves during gain filling, especially after the high grain filling.2.Removed ears in different days showed that starch was accumalated in the leaves and the steam at the same time,and starch was the end hoard form of the carbohydrate in the leaves and the steam.Sucrose was accumalated in the leaves during grain filling period,but lots of sucrose was accumalated in the steam during middle of grian filling period ,the sucrose was send to ears after the high grian filling period .Removed ears in different days showed that sucrose was accumalated in steam fist ,then sucrose was accumalated in leaves after the high grian filling period .The content of total sugar of the control's leaves was stable ,but it increased after the high grian filling,this is beacause the steam of the control is as the buffer sink,then the total suger was send to ears after the high grian filling period . Removed ears n different days showed that total sugar increased gradually .But total sugar in steam decreased after the high grian filling which showed that sugar was not the end hoard form of the carbohydrate removed ears after silking.