DNA marker-based study of genetic relatedness in United States sweetpotato cultivars

Abstract

The polymerase chain reaction (PCR)-based DNA amplification fingerprinting (DAF) approach was used to investigate genetic relationships among 30 U.S. sweetpotato (Ipomoea batatas L. Lam.) genotypes including heirloom cultivars and recent releases. Phenogram, pairwise similarity matrix, and principal coordinate plots we re developed based on Jaccard's coefficients using band-sharing data generated by seven octamer primers. All cultivars showed unique fingerprint patterns indicating the utility of DAF in cultivar identification. Many heirloom cultivars such as 'Creole' and 'Porto Rico' were readily differentiated from recently developed cultivars. Modern cultivars such as 'Jewel', 'Carver', 'Nugget', and 'Scarlet' exhibited a high degree of similarity reflecting ancestral relatedness. 'Regal' and 'Excel', recently developed using a population-based breeding approach, showed greater divergence from all other cultivars. Those cultivars, developed as a result of somatic mutations, exhibited high levels of genetic similarity to their normal-type parents and yet had distinct fingerprint profiles. With few exceptions, genetic relationships derived from DAF data appear to be consistent with available pedigree information.