%D 2006 %0 ARTICLE %T Targeting xa13 , a recessive gene for bacterial blight resistance in rice . %J Theor . Appl . Genet . %V 112 ( 3 ) %P 455-61 %A Chu Z %A Fu B %A Yang H %A Xu C %A Li Z %A Sanchez A %A Park YJ %A Bennetzen JL %A Zhang Q %A Wang S %M pub16328230 %X Bacterial blight , caused by Xanthomonas oryzae pv . oryzae ( Xoo ) , is one of the most serious diseases of rice worldwide . Thirty bacterial blight resistance ( R ) genes ( 21 dominant genes and 9 recessive genes ) in rice have been identified . They are the main sources for the genetic improvement of rice for resistance to Xoo . However , little is known about the recessive R genes . To clone and characterize the recessive R genes , we fine-mapped xa13 , a fully recessive gene for Xoo resistance , to a DNA fragment of 14 . 8 kb using the map-based cloning strategy and a series of sequence-based molecular markers . Sequence analysis of this fragment indicated that this region contains only two apparently intact candidate genes ( an extensin-like gene and a homologue of nodulin MtN3 ) and the 5 end of a predicted hypothetical gene . These results will greatly facilitate the isolation and characterization of xa13 . Four PCR-based markers , E6a , SR6 , ST9 and SR11 that were tightly linked to the xa13 locus , were also developed . These markers will be useful tools for the marker-assisted selection of xa13 in breeding programs .