Studies on the Relationship between Drought Tolerance and Photosynthetic Physiological of Maize Leaf

The change of net photosynthetic rate of leaf,chlorophyll content and chlorophyll fluorescence parameters were studied under water stress.The result showed that net photosynthetic rate of leaf(Pn),chlorophyll a(Chl a),chlorophyll b(Chl b),total chlorophyll content(Chl),value of chlorophyll a/b(Chl a/b),max fluorescence(Fm) and photochemical efficiency of PSⅡ(Fv/Fm) were decreased compared with the antitheses.The basis fluorescence(Fo) was increased.The ratio of Pn and Chl a/b in antitheses correlated positively to drought resistance very significantly(r=0.880 7**,p0.01;r=0.880 4**,p0.01).The ratio of Fo in antitheses correlated negative to drought resistance very significantly(r=-0.764 0*,p0.05).The ratio of Fm and Fv/Fm in antitheses correlated positively to drought resistance very significantly.So the net photosynthetic rate,the value of chlorophyll a/b,Fo,Fm and Fv/Fm could be used to evaluate the drought resistance of different sweet maize varieties.