Evaluation of the number and information content of fluorescent-labeled SSR markers for rice germplasm characterization.

The use of fluorescent-labelled simple sequence repeat (SSR) markers allows the simultaneous analysis of diverse loci in multiplex series, providing an enhanced precision of the determination of the allele size when a large number of genotypes is used. Twenty-five fluorescent-labelled SSR markers were used to genotype 242 accessions of the Brazilian Rice Core Collection. Based on the Polymorphism Information Content (PIC) values of each marker, groups with 5, 10, 15 and 20 markers were formed. The average PIC values varied from 0.67 to 0.89 and the number of alleles sampled per group, from 70 to 377. In the case of rice, which has a narrow genetic base, the conclusion was drawn that it is of fundamental importance that the genotypes must be evaluated by the highest possible number of regularly spaced SSR markers in the genome, and that these, preferentially, should offer a high information content