Relationship between Root Activity and Leaf Senescence in Different Adzuki Bean Cultivars (Lines)

In 2008~2009,high-yield cultivars '2000-75' and 'Jihong 9218',and low-yield cultivars 'Hongbao 1' and 'Wanxuan 1' of adzuki bean adopted in the summer-sowing areas were investigated for root and stem,growth index,anti-oxidative enzymes,soluble protein contents from the flowering stage to maturing stage,in order to promulgate the relationship between the root system and the leaf senescence.The result indicated that:(1)the root activity began to rise at the early flowering stage,peaked at the peak flowering and pods formation stage and then rapidly declined,but the root activity began to decline later than the leaf activity.(2)After flowing,the root activity,the anti-oxidative enzyme(SOD and CAT) activities,the contents of chlorophyll and soluble protein and photosynthetic rate of start leaves were positive,but the membrane lipid peroxidation product MDA content was negative.(3)Compared with low-yield cultivars,high-yield cultivars maintained higher root activities,chlorophyll contents,Pn and SOD,CAT activities in the late stages,indicating that delaying or slowing down the leaf senescence plays an important role on yield.