GENETIC DIVERSITY IN SOYBEAN OF THE HUMID TROPICS OF MÉXICO DETERMINED BY AFLP MARKERS

Abstract

Soybean [Glycine max (L.) Merrill] has a low level of genetic diversity in comparison with other self-pollinated species. In order to determine the need to introduce new germplasm for the development of new varieties, genetic diversity of soybean from the humid tropical region of México was evaluated using AFLP markers. A total of 24
lines developed in México and nine introductions from other countries were analyzed. Results revealed that lines did not group together according to their geographical origin. A high polymorphism level (60 %) was observed and the Mexican genotypes share a high level of genetic similarity with those from Brazil. The low genetic diversity index (31 %) was similar to those reported in other studies. Although the genotypes sampled did not represent all soybean germplasm in the humid tropics, results showed that the genetic diversity is to generate new cultivars, because three of the Mexican lines were more diver gent at the molecular level than foreign genotypes considered phylogenetically different (based on morphological and physiological traits), which were used as controls.