Molecular characterization of sweet cassava accessions adapted to the Brazil Central Cerrado

Abstract

The aim of the present work was to characterize, via RAPD markers, the genetic variability of 23 sweet cassava accessions conserved in the Cerrado Cassava Regional Germoplasm Bank (“Banco Regional de Germoplasma de Mandioca do Cerrado”-BGMC). The analyzed accessions were two varieties recommended for cultivation within the Cerrado Region, BGMC 982 and BGMC 753, and 21 landraces selected for presenting low contents of HCN in the  roots (lower than 100 ppm) and for adaptation to the Brazil Central Cerrado conditions. Under laboratorial conditions, the accessions were evaluated by using 11 RAPD primers, the matrix of similarity among the accessions being estimated afterwards, by using the Jaccard index. The primers generated 120 RAPD markers, among which 60% were polymorphic. Among the studied accessions, solely the group “Taquara Amarela” (BGMC 1289, BGMC 1290, BGMC 1291 and BGMC 1292) displayed high genetic similarity. The other accessions did not present tendency of grouping in hierarchic manner, i.e. in clusters that display similarity within the groups and divergence among groups. Neither any tendency of grouping of accessions in function of origin place/accession collection was observed. The study revealed the efficiency RAPD markers in the determination of genetic variability among sweet cassava accessions and that within the group of evaluated accessions there is high genetic variability which may be used in genetic breeding.