title: Introgression of blast resistance genes into the elite rice variety MR263 through marker-assisted backcrossing.
abstract: BACKGROUND
  Blast caused by the fungus Magnaporthe oryzae is a significant disease threat to rice across the world and is especially prevalent in Malaysia. An elite, early-maturing, high-yielding Malaysian rice variety, MR263, is susceptible to blast and was used as the recurrent parent in this study. To improve MR263 disease resistance, the Pongsu Seribu 1 rice variety was used as donor of the blast resistance Pi-7(t), Pi-d(t)1 and Pir2-3(t) genes and qLN2 quantitative trait locus (QTL). The objective was to introgress these blast resistance genes into the background of MR263 using marker-assisted backcrossing with both foreground and background selection.
  
  
  RESULTS
  Improved MR263-BR-3-2, MR263-BR-4-3, MR263-BR-13-1 and MR263-BR-26-4 lines carrying the Pi-7(t), Pi-d(t)1 and Pir2-3(t) genes and qLN2 QTL were developed using the simple sequence repeat (SSR) markers RM5961 and RM263 (linked to the blast resistance genes and QTL) for foreground selection and a collection of 65 polymorphic SSR markers for background selection in backcrossed and selfed generations. A background analysis revealed that the highest rate of recurrent parent genome recovery was 96.1% in MR263-BR-4-3 and 94.3% in MR263-BR-3-2.
  
  
  CONCLUSIONS
  The addition of blast resistance genes can be used to improve several Malaysian rice varieties to combat this major disease.
authors.affiliation: Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor, Malaysia.
authors.forename: Muhammad M
authors.initials: MM
authors.lastname: Hasan
authors.affiliation: Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor, Malaysia.|Laboratory of Food Crops, Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor, Malaysia.
authors.forename: Mohd Y
authors.initials: MY
authors.lastname: Rafii
authors.affiliation: Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor, Malaysia.
authors.forename: Mohd Razi
authors.initials: MR
authors.lastname: Ismail
authors.affiliation: Deparment of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor, Malaysia.
authors.forename: Maziah
authors.initials: M
authors.lastname: Mahmood
authors.affiliation: Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor, Malaysia.
authors.forename: Md Amirul
authors.initials: MA
authors.lastname: Alam
authors.affiliation: Agrotechnology and Bioscience Division, Malaysian Nuclear Agency, Bangi, 43000, Kajang, Selangor, Malaysia.
authors.forename: Harun
authors.initials: H
authors.lastname: Abdul Rahim
authors.affiliation: Bangladesh Institute of Nuclear agriculture (BINA), BAU Campus, 2202, Mymensingh, Bangladesh.
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Malek
authors.affiliation: Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, UPM Serdang, Selangor, Malaysia.|Bangladesh Rice Research Institute (BRRI), 1701, Gazipur, Bangladesh.
authors.forename: Mohammad Abdul
authors.initials: MA
authors.lastname: Latif
mesh_terms: D018744:DNA, Plant / Q000032:analysis; D060467:Disease Resistance; D017343:Genes, Plant; D005819:Genetic Markers; D005838:Genotype; D007178:Inbreeding / Q000379:methods*; D020082:Magnaporthe; D008296:Malaysia; D018895:Microsatellite Repeats; D012275:Oryza / Q000235:genetics* / Q000382:microbiology*; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology* / Q000517:prevention & control; D013045:Species Specificity
chemical_list: D018744:DNA, Plant; D005819:Genetic Markers
keywords: Pi gene; blast resistance; molecular markers; rice