GENETIC VARIATION AND PHYLOGENETIC RELATIONSHIPS AMONG MAIZE TYPES AND TEOSINTE AS REVEALED BY ISOZYMES AND RAPD MARKERS

Genetic variation and phylogenetic relationships among four types of yellow maize (Zea mays L.); dent, flint, sweet and pop corn, and their wild relative; teosinte (Zea mexicana), were assessed using isozymes and random amplified polymorphic DNA (RAPD) markers. The results indicated that the percentage of polymorphic loci; for peroxidase and esterase isozymes, were 66.67% and 92.59%, respectively. By applying RAPD analysis, 116 bands were obtained from seven primers with 87.07% polymorphism. The UPGMA dendrogram based on genetic distance segregated the five genotypes into two main clusters. Both isozymes and RAPD markers separated teosinte into the first cluster, whereas the four maize types were grouped together in the seconds cluster. Dent and flint types were much close to each other with high similarity indices; 0.842 and 0.792 based on peroxidase and esterase isozymes, respectively. Furthermore, the flint type closely related to sweet type in RAPD cluster (similarity index of 0.588). This high variability detected among maize types and teosinte can be used in breeding programs to maximize the use of genetic resources.