GENETIC CHARACTERIZATION OF THREE EGYPTIAN SWEET POTATO GENOTYPES BASED ON MORPHO-AGRONOMIC AND MOLECULAR MARKERS

Abstract

Morpho-agronomic and chemical analysis as well as RAPD markers were used to determine the genetic diversity among three Egyptian genotypes of sweet potato; Abees, Mabrouka and Gendawy. The results revealed that there is a wide variation among the three genotypes in most morphological and agronomic characters in addition to the nutritional values. Gendawy genotype had the highest values for most agronomic and chemical traits compared to the other two genotypes; therefore it is considered a good source of agronomic and nutritional traits for breeding. Regarding molecular characterization, a total of nine RAPD primers were used to assess the genetic variability and relationships among the three sweet potato genotypes. A total of 146 amplified bands were generated from the nine primers with 52.74% polymorphism indicating high genetic variability. Cluster analysis revealed a close genetic relationship between Abees and Gendawy genotypes (similarity value of 0.718), while Mabrouka was the most distinct genotype. Results concluded that RAPD analysis could not be effective in separating genotypes according to their morphological, agronomic or chemical characters. In addition, characterization based on these conventional characters should be complemented with DNA-based molecular characterization to reveal genetic diversity in the three Egyptian sweet potato genotypes.