6Vamerali T,Saccomani M,Bona S.A comparison of root char-acteristics in relation to nutrient and water stress in two corn hy-brids[J].Plant Soil,2003,255:157-167.
7Farre I,Oijen M V,Leffelaar P A.Analysis of maize growthfor different irrigation strategies in northeastern Spain[J].Eur.J.Agron.,2000,12:225-238.
8Bradford M M.A rapid and sensitive method for the quantita-tion of microgram quantities of protein utilizing the principle ofprotein-dye binding[J].Anal.Biochem.,1976,72:248-254.
