Development of Interspecific NILs for Yield Enhancement in Rice

Though the complete genome sequence of rice became available in 2005, the development of improved varieties containing optimal combinations of the 30,000 genes in the rice genome remains a logistical challenge for plant breeders. Work in the McCouch Rice Lab has previously shown that introgressing the QTL, Yld6.1, from a low-yielding wild ancestor, Oryza rufipogon, can improve performance of the high-yielding elite US cultivar, O. sativa cv. Jefferson. Approximately 300 BC3F2 progeny from a Jefferson/O. rufipogon cross were screened using SNPs and SSR markers to identify recombinants carrying the favorable allele from O. rufipogon at the Yld6.1 locus and no (or few) background introgressions in the rest of the genome. Using this approach, 3 near isogenic lines (NILs) were selected. These NILs will go through one generation of seed amplification in Puerto Rico during winter 2009-10 before being evaluated in the field during summer 2010 to determine whether they outperform the Jefferson parent.