title: Mapping Quantitative Trait Loci Controlling High Iron and Zinc Content in Self and Open Pollinated Grains of Pearl Millet [Pennisetum glaucum(L.) R. Br.].
abstract: Pearl millet is a multipurpose grain/fodder crop of the semi-arid tropics, feeding many of the world's poorest and most undernourished people. Genetic variation among adapted pearl millet inbreds and hybrids suggests it will be possible to improve grain micronutrient concentrations by selective breeding. Using 305 loci, a linkage map was constructed to map QTLs for grain iron [Fe] and zinc [Zn] using replicated samples of 106 pearl millet RILs (F6) derived from ICMB 841-P3 × 863B-P2. The grains of the RIL population were evaluated for Fe and Zn content using atomic absorption spectrophotometer. Grain mineral concentrations ranged from 28.4 to 124.0 ppm for Fe and 28.7 to 119.8 ppm for Zn. Similarly, grain Fe and Zn in open pollinated seeds ranged between 22.4-77.4 and 21.9-73.7 ppm, respectively. Mapping with 305 (96 SSRs; 208 DArT) markers detected seven linkage groups covering 1749 cM (Haldane) with an average intermarker distance of 5.73 cM. On the basis of two environment phenotypic data, two co-localized QTLs for Fe and Zn content on linkage group (LG) 3 were identified by composite interval mapping (CIM). Fe QTL explained 19% phenotypic variation, whereas the Zn QTL explained 36% phenotypic variation. Likewise for open pollinated seeds, the QTL analysis led to the identification of two QTLs for grain Fe content on LG3 and 5, and two QTLs for grain Zn content on LG3 and 7. The total phenotypic variance for Fe and Zn QTLs in open pollinated seeds was 16 and 42%, respectively. Analysis of QTL × QTL and QTL × QTL × environment interactions indicated no major epistasis.
authors.affiliation: Plant Biotechnology Centre, Swami Keshwanand Rajasthan Agricultural UniversityBikaner, India; International Crops Research Institute for the Semi-Arid TropicsPatancheru, India; Centre of Excellence in Agricultural Biotechnology, Anand Agricultural UniversityAnand, India.
authors.forename: Sushil
authors.initials: S
authors.lastname: Kumar
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics Niamey, Niger.
authors.forename: Charles T
authors.initials: CT
authors.lastname: Hash
authors.affiliation: Indian Agricultural Research Institute, New Delhi India.
authors.forename: Nepolean
authors.initials: N
authors.lastname: Thirunavukkarasu
authors.affiliation: Plant Biotechnology Centre, Swami Keshwanand Rajasthan Agricultural University Bikaner, India.
authors.forename: Govind
authors.initials: G
authors.lastname: Singh
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics Patancheru, India.
authors.forename: Vengaldas
authors.initials: V
authors.lastname: Rajaram
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics Patancheru, India.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Rathore
authors.affiliation: Directorate of Oilseeds Research Hyderabad, India.
authors.forename: Senthilvel
authors.initials: S
authors.lastname: Senapathy
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics Patancheru, India.
authors.forename: Mahesh D
authors.initials: MD
authors.lastname: Mahendrakar
authors.affiliation: Crop Genetics, Genomics and Breeding Division, Aberystwyth University Aberystwyth, UK.
authors.forename: Rattan S
authors.initials: RS
authors.lastname: Yadav
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics Patancheru, India.
authors.forename: Rakesh K
authors.initials: RK
authors.lastname: Srivastava
keywords: QTL; RIL; biofortification; iron and zinc; pearl millet