Hybrid rice heterosis and genetic diversity of IRRI and Lao rice

Glutinous and non-glutinous rice hybrids derived from IRRI and Lao PDR rice germplasm were evaluated for yield heterosis and genetic diversity based on SSR markers. Pollen and spikelet fertilities of the hybrids showed absence of effective restorer and maintainer genes in the Lao varieties for WA-CMS cytoplasm. Positive heterosis over better or male parent (Lao varieties) was observed. Hybrids derived from an IRRIs TGMS line with Lao varieties showed a great potential in hybrid rice application. Genetic diversity among the rice lines was assessed by COP and SSR markers. Cluster analysis based on the molecular markers generated three parental groups in agreement with parental pedigree information. Significant linear relation was detected between yield heterosis and marker-based genetic distance of parents.