title: Molecular mapping of genomic regions harbouring QTLs for root and yield traits in sorghum (Sorghum bicolor L. Moench).
abstract: Root system is a vital part of plants for absorbing soil moisture and nutrients and it influences the drought tolerance. Identification of the genomic regions harbouring quantitative trait loci (QTLs) for root and yield traits, and the linked markers can facilitate sorghum improvement through marker-assisted selection (MAS) besides the deeper understanding of the plant response to drought stress. A population of 184 recombinant inbred lines (RILs), derived from E36-1 × SPV570, along with parents were phenotyped for component traits of yield in field and root traits in an above ground rhizotron. High estimates of heritability and genetic advance for all the root traits and for most of the yield traits, presents high scope for improvement of these traits by simple selection. A linkage map constructed with 104 marker loci comprising 50 EST-SSRs, 34 non-genic nuclear SSRs and 20 SNPs, and QTL analysis was performed using composite interval mapping (CIM) approach. A total of eight and 20 QTLs were mapped for root and yield related traits respectively. The QTLs for root volume, root fresh weight and root dry weight were found co-localized on SBI-04, supported by a positive correlation among these traits. Hence, these traits can be improved using the same linked markers. The lack of overlap between the QTLs of component traits of root and yield suggested that these two sets of parameters are independent in their influence and the possibility of combining these two traits might enhance productivity of sorghum under receding moisture condition.
authors.affiliation: Institute of Agri-Biotechnology, University of Agricultural Sciences, Dharwad, Dharwad, 580 005 Karnataka India.
authors.lastname: Rajkumar
authors.affiliation: Institute of Agri-Biotechnology, University of Agricultural Sciences, Dharwad, Dharwad, 580 005 Karnataka India.
authors.forename: B
authors.initials: B
authors.lastname: Fakrudin
authors.affiliation: Institute of Agri-Biotechnology, University of Agricultural Sciences, Dharwad, Dharwad, 580 005 Karnataka India.
authors.forename: S P
authors.initials: SP
authors.lastname: Kavil
authors.affiliation: School of Plant Sciences and NRMES, Haramaya University, Alemaya City, Ethiopia.
authors.forename: Y
authors.initials: Y
authors.lastname: Girma
authors.affiliation: Bioinformatics Core, Purdue University, West Lafayette, IN 47907 USA.
authors.forename: S S
authors.initials: SS
authors.lastname: Arun
authors.affiliation: Institute of Agri-Biotechnology, University of Agricultural Sciences, Dharwad, Dharwad, 580 005 Karnataka India.
authors.forename: D
authors.initials: D
authors.lastname: Dadakhalandar
authors.affiliation: Institute of Agri-Biotechnology, University of Agricultural Sciences, Dharwad, Dharwad, 580 005 Karnataka India.
authors.forename: B H
authors.initials: BH
authors.lastname: Gurusiddesh
authors.affiliation: Institute of Agri-Biotechnology, University of Agricultural Sciences, Dharwad, Dharwad, 580 005 Karnataka India.
authors.forename: A M
authors.initials: AM
authors.lastname: Patil
authors.affiliation: International Crop Research Institute for Semi-Arid Tropics, Patancheru, Hyderabad, India.
authors.forename: M
authors.initials: M
authors.lastname: Thudi
authors.affiliation: Institute of Agri-Biotechnology, University of Agricultural Sciences, Dharwad, Dharwad, 580 005 Karnataka India.
authors.forename: S B
authors.initials: SB
authors.lastname: Bhairappanavar
authors.affiliation: All India Coordinated Sorghum Improvement Programme, Main Agricultural Research Station, Dharwad, India.
authors.forename: Y D
authors.initials: YD
authors.lastname: Narayana
authors.affiliation: Institute of Agri-Biotechnology, University of Agricultural Sciences, Dharwad, Dharwad, 580 005 Karnataka India.
authors.forename: P U
authors.initials: PU
authors.lastname: Krishnaraj
authors.affiliation: University of Agricultural Sciences, Dharwad, Dharwad, India.
authors.forename: B M
authors.initials: BM
authors.lastname: Khadi
authors.affiliation: All India Coordinated Sorghum Improvement Programme, Main Agricultural Research Station, Dharwad, India.
authors.forename: M Y
authors.initials: MY
authors.lastname: Kamatar
keywords: Linkage map; QTLs mapping; Root traits; Sorghum; Variability and correlation analysis