title: Incorporation of Bacterial Blight Resistance Genes Into Lowland Rice Cultivar Through Marker-Assisted Backcross Breeding.
abstract: Bacterial blight (BB) of rice caused by Xanthomonas oryzae pv. oryzae is a major disease of rice in many rice growing countries. Pyramided lines carrying two BB resistance gene combinations (Xa21+xa13 and Xa21+xa5) were developed in a lowland cultivar Jalmagna background through backcross breeding by integrating molecular markers. In each backcross generation, markers closely linked to the disease resistance genes were used to select plants possessing the target genes. Background selection was continued in those plants carrying resistant genes until BC(3) generation. Plants having the maximum contribution from the recurrent parent genome were selected in each generation and hybridized with the recipient parent. The BB-pyramided line having the maximum recipient parent genome recovery of 95% was selected among BC3F1 plants and selfed to isolate homozygous BC(3)F(2) plants with different combinations of BB resistance genes. Twenty pyramided lines with two resistance gene combinations exhibited high levels of tolerance against the BB pathogen. In order to confirm the resistance, the pyramided lines were inoculated with different X. oryzae pv. oryzae strains of Odisha for bioassay. The genotypes with combination of two BB resistance genes conferred high levels of resistance to the predominant X. oryzae pv. oryzae isolates prevalent in the region. The pyramided lines showed similarity with the recipient parent with respect to major agro-morphologic traits.
authors.affiliation: First, second, third, fourth, fifth, sixth, and seventh authors: Crop Improvement Division, National Rice Research Institute, Cuttack, Odisha, India; and eighth author: Department of Botany, Ravenshaw University, Cuttack, Odisha, India.
authors.forename: Sharat Kumar
authors.initials: SK
authors.lastname: Pradhan
authors.affiliation: First, second, third, fourth, fifth, sixth, and seventh authors: Crop Improvement Division, National Rice Research Institute, Cuttack, Odisha, India; and eighth author: Department of Botany, Ravenshaw University, Cuttack, Odisha, India.
authors.forename: Deepak Kumar
authors.initials: DK
authors.lastname: Nayak
authors.affiliation: First, second, third, fourth, fifth, sixth, and seventh authors: Crop Improvement Division, National Rice Research Institute, Cuttack, Odisha, India; and eighth author: Department of Botany, Ravenshaw University, Cuttack, Odisha, India.
authors.forename: Elssa
authors.initials: E
authors.lastname: Pandit
authors.affiliation: First, second, third, fourth, fifth, sixth, and seventh authors: Crop Improvement Division, National Rice Research Institute, Cuttack, Odisha, India; and eighth author: Department of Botany, Ravenshaw University, Cuttack, Odisha, India.
authors.forename: Lambodar
authors.initials: L
authors.lastname: Behera
authors.affiliation: First, second, third, fourth, fifth, sixth, and seventh authors: Crop Improvement Division, National Rice Research Institute, Cuttack, Odisha, India; and eighth author: Department of Botany, Ravenshaw University, Cuttack, Odisha, India.
authors.forename: Annamalai
authors.initials: A
authors.lastname: Anandan
authors.affiliation: First, second, third, fourth, fifth, sixth, and seventh authors: Crop Improvement Division, National Rice Research Institute, Cuttack, Odisha, India; and eighth author: Department of Botany, Ravenshaw University, Cuttack, Odisha, India.
authors.forename: Arup Kumar
authors.initials: AK
authors.lastname: Mukherjee
authors.affiliation: First, second, third, fourth, fifth, sixth, and seventh authors: Crop Improvement Division, National Rice Research Institute, Cuttack, Odisha, India; and eighth author: Department of Botany, Ravenshaw University, Cuttack, Odisha, India.
authors.forename: Srikanta
authors.initials: S
authors.lastname: Lenka
authors.affiliation: First, second, third, fourth, fifth, sixth, and seventh authors: Crop Improvement Division, National Rice Research Institute, Cuttack, Odisha, India; and eighth author: Department of Botany, Ravenshaw University, Cuttack, Odisha, India.
authors.forename: Durga Prasad
authors.initials: DP
authors.lastname: Barik
mesh_terms: D018745:Genome, Plant; D054884:Host-Pathogen Interactions / Q000235:genetics*; D012275:Oryza / Q000382:microbiology / Q000502:physiology*; D000069600:Plant Breeding / Q000379:methods*; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology; D057865:Plant Immunity / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D014974:Xanthomonas / Q000502:physiology*
chemical_list: D010940:Plant Proteins; C097148:Xa21 protein, Oryza sativa; D017346:Protein Serine-Threonine Kinases
keywords: foreground selection; gene pyramiding; marker-assisted selection