title: Fine-mapping and identification of a candidate gene underlying the d2 dwarfing phenotype in pearl millet, Cenchrus americanus (L.) Morrone.
abstract: Pearl millet is one of the most important subsistence crops grown in India and sub-Saharan Africa. In many cereal crops, reduced height is a key trait for enhancing yield, and dwarf mutants have been extensively used in breeding to reduce yield loss due to lodging under intense management. In pearl millet, the recessive d2 dwarfing gene has been deployed widely in commercial germplasm grown in India, the United States, and Australia. Despite its importance, very little research has gone into determining the identity of the d2 gene. We used comparative information, genetic mapping in two F2 populations representing a total of some 1500 progeny, and haplotype analysis of three tall and three dwarf inbred lines to delineate the d2 region by two genetic markers that, in sorghum, define a region of 410 kb with 40 annotated genes. One of the sorghum genes annotated within this region is ABCB1, which encodes a P-glycoprotein involved in auxin transport. This gene had previously been shown to underlie the economically important dw3 dwarf mutation in sorghum. The cosegregation of ABCB1 with the d2 phenotype, its differential expression in the tall inbred ICMP 451 and the dwarf inbred Tift 23DB, and the similar phenotype of stacked lower internodes in the sorghum dw3 and pearl millet d2 mutants suggest that ABCB1 is a likely candidate for d2.
authors: Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Athens, Georgia 30602, USA.
authors: Rajiv K
authors: RK
authors: Parvathaneni
authors: Vinod
authors: V
authors: Jakkula
authors: Francis K
authors: FK
authors: Padi
authors: Sebastien
authors: S
authors: Faure
authors: Nethra
authors: N
authors: Nagarajappa
authors: Ana C
authors: AC
authors: Pontaroli
authors: Xiaomei
authors: X
authors: Wu
authors: Jeffrey L
authors: JL
authors: Bennetzen
authors: Katrien M
authors: KM
authors: Devos
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport; D002874:Chromosome Mapping / Q000379:methods*; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics / Q000378:metabolism; D003433:Crosses, Genetic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005808:Genes, Recessive; D056426:Genetic Loci; D005819:Genetic Markers; D006239:Haplotypes; D007210:Indoleacetic Acids / Q000378:metabolism; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D009154:Mutation; D031782:Pennisetum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D005819:Genetic Markers; D007210:Indoleacetic Acids; D010940:Plant Proteins
keywords: P-glycoprotein; comparative genomics; fine-mapping; haplotype analysis