Abstract

The comparison of different methods of estimating the genetic diversity could define their usefulness in plant breeding and conservation programs. In this study, a total of 15 morphological traits, eight AFLP-primer combinations and 20 simple sequence repeat (SSR) loci were used (i) to study the morphological and genetic diversity among 62 selected highland maize accessions, (ii) to assess the level of correlation between phenotypic and genetic distances, and (iii) to classify the accessions into groups based on molecular profiles and morphological traits. The analysis of variance of the morphological data revealed significant differences among accessions for all measured traits. The mean morphological dissimilarity (0.3 with a range of 0.1-0.68) was low in comparison to dissimilarity calculated using SSR markers (0.49 with a range 0.27-0.63) and AFLP markers (0.57 with a range 0.32-0.69). The correlation between the morphological dissimilarity matrix and the matrices of genetic dissimilarity based on SSR and AFLP markers was 0.43 and 0.39, respectively (p = 0.001). The correlation between SSRs and AFLPs dissimilarity matrices was 0.67 (p = 0.001). This congruence indicates that both marker systems are equally suited for genetic diversity study of maize accessions. Cluster analysis of morphological and marker distances revealed three groups of maize accessions with distinctive genetic profiles and morphological traits. This information will be useful for collections, conservation and various breeding programs in the highlands of Ethiopia.

Key words:  AFLP, correlation, phenotypic diversity, SSR.