Both RAPD and SSR markers were used to evaluate
108 accessions of irrigated and upland rice representing the
genetic basis of rice breeding in Brazil (“reference collection
– RC”), including the parental lines of recurrent selection
populations such as CNA-5, as well as two O.
glumaepatula accessions and one O. rufipogonn accession.
Cluster analysis based on 114 RAPD markers and 13 SSR
loci detected strong genetic structuring of the RC accessions
in two groups corresponding to the subspecies indica
(36% of the accessions) and japonica (64% of the accessions).
The data based on RAPD and SSR polymorphic
markers was contrasted with morphological, botanical and
crop system information. Results indicated that the use of
four indica/japonica-specific RAPD markers could reliably
classify a rice accession at the subspecific level, providing
a useful tool for fast analysis of large collections.
The data also indicated that some accessions are probably
derived from indica x japonica crosses (I/J). The four indica/
japonica-specific RAPD markers were used to fingerprint
267 lines of the CMS hybrid program. The data
indicated that nine lines were japonica, 104 were indica
and 158 a possible intercross (I/J) between the two subspecies. It was interesting to notice that several
maintainers have a genetic background (I/J) that differs
from that observed in the male sterile lines (indica). Polymorphism
between male sterile lines and their current
maintainers at 11 SSR loci detected with the two multiplex
systems confirmed these differences, as mentioned below