Molecular characterization of ‘sweet’ cassavas (Manihot esculenta) from a germplasm bank in Brazilian Eastern Amazonia
Elisa Ferreira Moura Cunha, Carlos Rogério de Sousa Silva, Paulo Sérgio Bevilaqua de Albuquerque, Girena Fernandes Ramalho, Lígia Cristine Gonçalves Pontes and João Tomé de Farias Neto
Abstract – Genetic variability of a set of 81 accessions of ‘sweet’ cassavas (Manihot esculenta) collected mostly in the North region of Brazil was investigated with nine microsatellite loci. All loci were polymorphic, with mean of 6.33 alleles per locus. Analyses indicated that 35 multiloci profiles were represented by a single accession, and 46 showed non-unique profiles, represented by eleven genotypes. Forty-six different multiloci profiles were detected. Most of the putative duplicated accessions were collected in different locations. After the removal of putative duplicated genotypes, genetic parameters were estimated and expected heterozygosity was high (HE=0.73), indicating genetic variability. Structure analysis of this set of ‘sweet’ cassavas divided the 46 genotypes into two clusters (K=2), and a few genotypes had mixed ancestry. Results indicated the habit of exchange of materials among farmers of the North region of Brazil, and the genetic variability to be exploited in genetic breeding efforts.