ISOZIMATIC VARIATION OF TEOSINTE POPULATIONS

Abstract

The degree of genetic variation in teosinte (Zea mays ssp.), was analyzed with starch gels in 27 isozymic loci, codified by 17 enzymatic systems, in 46 to 50 individuals from each of six populations. The genetic variation was estimated based on the average number of alleles per locus (NPAL), polymorphism percentage (P), observed and expected heterozygosity (H_O and H_E), heterozygote relative index (IRH) and Shannon index (IS). For NPAL and P, the average for the six populations was 2.24 and 62 %, respectively. The analysis of H_O and H_E revealed that the genetic variation in the teosinte populations was high, with average values of 0.13 and 0.19, respectively. The IRH revealed a deficiency of heterozygote genotypes (average of -0.33). The IS showed great diversity in the six populations (0.35). The populations with greatest genetic variation belonged to Zea mays ssp. mexicana, followed by those of Z. m. ssp. parviglumis and Z. diploperennis.