Esterase isozymes of different maize varieties were analyzed by polyacrylamide gel electrophoresis.The results showed rich expression and strong specificity in enzyme spectrums of all the varieties,and there were stable and consistent bands of basic enzymes in many alleles.There were 76 enzyme bands in total for experiment materials.The numbers were significantly different between varieties,10 for the largest and 5 for the least.Some varieties possessed similar enzyme sites,but there were specific enzyme bands in various types due to different degree of staining.In the relationships,Ganxinhuanuo No.1 and Taiwanchaotian No.38 were the farthest,Yuhe 988 and Yucaitiannuo No.1 were closer,and Luoyang 800,Shendan 16 and Ludan 981 were the nearest based on calculation of zymography combined coefficient.

A fast,simple and convenient method is established to isolate and characterize the cpDNA in leaves of Quercus variabilis.The protocol includes: chloplast isolation,deoxyribonuclease treatment,deproteinisation and purification of the DNA.The technique is inexpensive and appropriate for the isolation of cpDNA and is easy to obtain cpDNA with high purity and high quality.RAPD analysis system has also been established for study of this cpDNA.