title: Marker-assisted introgression of a QTL region to improve rust resistance in three elite and popular varieties of peanut (Arachis hypogaea L.).
abstract: Successful introgression of a major QTL for rust resistance, through marker-assisted backcrossing, in three popular Indian peanut cultivars generated several promising introgression lines with enhanced rust resistance and higher yield. Leaf rust, caused by Puccinia arachidis Speg, is one of the major devastating diseases in peanut (Arachis hypogaea L.). One QTL region on linkage group AhXV explaining upto 82.62 % phenotypic variation for rust resistance was validated and introgressed from cultivar 'GPBD 4' into three rust susceptible varieties ('ICGV 91114', 'JL 24' and 'TAG 24') through marker-assisted backcrossing (MABC). The MABC approach employed a total of four markers including one dominant (IPAHM103) and three co-dominant (GM2079, GM1536, GM2301) markers present in the QTL region. After 2-3 backcrosses and selfing, 200 introgression lines (ILs) were developed from all the three crosses. Field evaluation identified 81 ILs with improved rust resistance. Those ILs had significantly increased pod yields (56-96 %) in infested environments compared to the susceptible parents. Screening of selected 43 promising ILs with 13 markers present on linkage group AhXV showed introgression of the target QTL region from the resistant parent in 11 ILs. Multi-location field evaluation of these ILs should lead to the release of improved varieties. The linked markers may be used in improving rust resistance in peanut breeding programmes.
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, 502324, India, r.k.varshney@cgiar.org.
authors.forename: Rajeev K
authors.initials: RK
authors.lastname: Varshney
authors.forename: Manish K
authors.initials: MK
authors.lastname: Pandey
authors.forename: Pasupuleti
authors.initials: P
authors.lastname: Janila
authors.forename: Shyam N
authors.initials: SN
authors.lastname: Nigam
authors.forename: Harikishan
authors.initials: H
authors.lastname: Sudini
authors.forename: M V C
authors.initials: MV
authors.lastname: Gowda
authors.forename: Manda
authors.initials: M
authors.lastname: Sriswathi
authors.forename: T
authors.initials: T
authors.lastname: Radhakrishnan
authors.forename: Surendra S
authors.initials: SS
authors.lastname: Manohar
authors.forename: Patne
authors.initials: P
authors.lastname: Nagesh
mesh_terms: D010367:Arachis / Q000235:genetics* / Q000276:immunology* / Q000382:microbiology; D001487:Basidiomycota / Q000502:physiology*; D003433:Crosses, Genetic; D060467:Disease Resistance / Q000235:genetics*; D008040:Genetic Linkage; D005819:Genetic Markers; D018745:Genome, Plant / Q000235:genetics; D005838:Genotype; D007178:Inbreeding; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D040641:Quantitative Trait Loci / Q000235:genetics*; D057945:Self-Fertilization
chemical_list: D005819:Genetic Markers