GENETIC-VARIATION AMONG SWEET-POTATOES PROPAGATED THROUGH NODAL AND ADVENTITIOUS SPROUTS

Genetic uniformity was assessed among sweetpotato (Ipomoea batatas) cl ones propagated through adventitious and nodal procedures. A single sp rout each of 'Jewel', 'Sumor', and L87-95 was used as source of clonal plants that were simultaneously propagated through conventional adven titious procedures and a tissue culture-based nodal culture technique. A sample of 15 decamer primers generated 64 scorable amplified fragme nts in a PCR-based assay, 29 of which were putatively polymorphic acro ss n = 60 samples (10 each of nodal and adventitiously derived plants/ genotype). Within adventitiously derived materials, putative polymorph isms ranged from 4.7% to 31.3% depending on the genotypic. class. In c ontrast, putative polymorphisms ranged from 0.0% to 3.1% among nodally derived samples. Marker loci differentiated genotypes as wed as putat ive marker phenotype variants through a multidimensional scaling analy sis of the genetic similarity matrix. An 'analysis of molecular varian ce' shows that genotypic effects accounted for 88.7% of the total mole cular marker variability, while propagation effects (within genotypic groups) accounted for 11.3%. Results confirm that clonal plants derive d from preexisting meristematic regions are more genetically uniform t han plants propagated from adventitious origins.