Effects of nitrogen fertilizer rate on leaf color of chimera Hosta 'Gold standard'

The effects of four nitrogen levels(0,1,2,3 g/kg soil) on leaf color,chlorophyll contents,total N contents,key enzymes activities of nitrogen metabolism and chloroplast ultrastructure of chimera Hosta 'Gold standard' were studied.Nitrogen levels mainly influenced the colour of the yellow leaf area of Hosta 'Gold standard'.The chimera characteristics were maintained under 0 and 1 g/kg nitrogen levels.There were no significant differences in chlorophyll contents,total N contents,and activities of key enzymes of nitrogen metabolism.The formation of chloroplasts which lack normal grana stacking was severely inhibited in the yellow leaf area.Under 2 and 3 g/kg nitrogen levels,the yellow leaf area became green.Compared with the indexes under 0 and 1 g/kg nitrogen levels,chlorophyll contents,total N contents and activities of key enzymes of nitrogen metabolism were significantly increased.Chloroplast ultrastructure was fully developed and normal thylakoid lamellar structure was formed.