It takes approximately 14 yr to produce a new rice (
Oryza sativa
L.) variety, that is, from initial hybridization to its
commercial release. Currently, new varieties are identified based on morphological descriptors, which have been efficient
over time. However, due to the main constraints on seed type impose to other breeding objectives and the pressure of
continuous release of varieties, high degree of parentage, and genetic and morphological uniformity has been observed
in the breeding populations. The objectives of this study were: to determine the genetic variability of Chilean and foreign
commercial rice varieties, and determine, identify, and certify the genetic relationships among varieties, using simple
sequence repeat (SSR) markers. A total of 16 commercial varieties, some of them closely related, were included in the
study, which were genetically analyzed using 54 microsatellites. The 54 microsatellite loci allowed the discrimination
among the 16 varieties. The number of alleles ranged between 2 and 8 with a mean of 3.54 alleles per locus, while the
polymorphism information content (PIC) presented a mean of 0.44. The genetic distance and diversity parameters between
pairs of varieties indicate a limited diversity among these genotypes. The cluster analysis indicated that varieties were
grouped according to their grain type and pedigree. Results demonstrate that the identification and certification of varieties
using microsatellite markers could be a good complement to existing agro-morphological data when varieties are closed
related.
