The chl (a/b) value of different type cultivars (lines) showed a decreasing trend at whole growth stage,and chl (a/b) value of medium grain type cultivars was lower than those of other type cultivars.

• 不同类型品种 (系 )叶绿素 (a/b)值在整个生育期呈下降趋势 ,中粒型品种 (系 )的chl(a/b)均低于另外两种类型品种 (系 )。