Analysis of the genus Zea (Poaceae) using polymorphic chloroplast simple sequence repeats

We have used polymorphic chloroplast simple sequence repeats (cpSSRs) to an alyse levels of diversity and relationships within the genus Zea. Between t wo and nine alleles were found at 15 polymorphic loci and combining the dat a from these loci gave 32 haplotypes in the 37 accessions studied. Genetic differentiation between the two sections within the genus was calculated us ing the PST statistic which showed that similar to 70% of the total variati on was found to exist between the sections. A phylogenetic analysis based o n the delta mu(2) distance metric showed a large split between the two sect ions and suggested multiple origins of modern cultivated maize Zea mays sub sp. mays. The agreement of the phylogenetic tree with other molecular, morp hological and karyological studies suggests that cpSSRs may have value in p hylogenetic studies in plants.