Two Outstanding Oryza glaberrima (2n = 24, AA) varieties TOG5681 and TOG5674 were used as male donor parents with IR64, the high-yielding improved Asian rice variety used as recurrent female parent by the International Rice Research Institute (IRRI) to develop 18 BC 3 F 1 interspecific lowland rice progenies. The proportion of parental genomic contribution and the extent of genetic differences among these lines were assessing using 36 microsatellites markers. The average genomic contribution of the donor TOG5681 and that of the recurrent IR64 within their 12 interspecific lines derived from IR64xTOG5681 cross were estimated to 13.2% and 79.8% respectively. Using 33 out of the 36 SSR markers, the average genome introgression rate of TOG5674 and that of IR64 within their 6 progenies were estimated to 8.7% and 85.5% respectively. In addition, heterozygosity and non-parental alleles were also identified. Clustering analysis technique using NTSYS classified the progenies into six groups and group five is closely related to IR 64.

NERICA rices are interspecific inbred progeny derived from crosses between 4% (1,508 cM), while the observed average proportion of O. glaberrima donor genome was 6.3% (108 cM). Non-parental alleles were detected in 83% of the lines and contributed an average of 38 cM per line (~2.2% of genomic DNA). Lines that had undergone eight generations of inbreeding in the field contained significantly more non-parental alleles (av. 2.7%) compared to the DH lines (av. 1.3%) that were developed from BC 2 anthers. Using both cluster and principal component analyses, two major groups were detected in these materials. The NERICA varieties (NERICA 1 to 7) clustered in one group while the remaining 63 lines clustered in another group, suggesting that the second group may offer significant opportunities for further selection and variety development.

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