CONTRASTING GENETIC DIVERSITY RELATIONSHIPS ARE REVEALED IN RICE (ORYZA-SATIVA L) USING DIFFERENT MARKER TYPES

Genetic variation between samples of Oryza sativa from 19 localities i n Bangladesh and Bhutan was assessed using two PCR-based molecular mar ker systems: RAPD (random amplification of polymorphic DNA) and ISSR-P CR (inter-simple sequence repeat polymerase chain reaction). Employing RAPD, a set of 14 decanucleotides of arbitrary sequence directed the amplification of 94 reproducible marker bands, 47 (50%) of which were polymorphic. In addition, a set of 9 ISSR primers were used to direct amplification of 71 PCR products, 40 (56%) of which were polymorphic. Multivariate analyses of the two PCR-based molecular marker data sets provided evidence that the patterns of variation correspond with the c lassification described by Glaszmann [9] using isozyme analysis. Subtl e differences in the relationships revealed between rice groups using the two types of PCR-based marker led to investigations of their map p ositions using an intraspecific doubled haploid mapping population. Th e observation that the chromosomal locations of markers can influence diversity assessments is presented and the significance of this is dis cussed.