title: Quantitative trait loci for callus initiation and totipotency in maize (Zea mays L.).
abstract: Induction of embryogenic callus in culture is an important step in plant transformation procedures, but response is genotype specific and the genetics of the trait are not well understood. Quantitative trait loci (QTL) were mapped in a set of 126 recombinant inbred lines (RILs) of inbred H99 (high Type I callus response) by inbred Mo17 (low Type I callus response) that were evaluated over two years for Type I callus response. QTL were observed in a total of eleven bins on eight chromosomes, including eight QTL with main effects and three epistatic interactions. Many of the QTL were mapped to the same or bordering chromosomal bins as candidate genes for abscisic acid metabolism, indicating a possible role for the hormone in the induction of embryogenic callus, as has previously been indicated in microspore embryo induction. Further examinations of allelic variability for known candidate genes located near the observed QTL could be useful for expanding the understanding of the genetic basis of induction embryogenic callus. The QTL observed herein could also be used in a marker assisted selection (MAS) program to improve the response of agronomically useful inbreds, but only if the resources required for MAS are lower than those required for phenotypic selection.
authors.affiliation: Department of Agronomy, Iowa State University, Ames, IA 50011, USA. mkrakowsky@tifton.usda.gov
authors.forename: M D
authors.initials: MD
authors.lastname: Krakowsky
authors.forename: M
authors.initials: M
authors.lastname: Lee
authors.forename: L
authors.initials: L
authors.lastname: Garay
authors.forename: W
authors.initials: W
authors.lastname: Woodman-Clikeman
authors.forename: M J
authors.initials: MJ
authors.lastname: Long
authors.forename: N
authors.initials: N
authors.lastname: Sharopova
authors.forename: B
authors.initials: B
authors.lastname: Frame
authors.forename: K
authors.initials: K
authors.lastname: Wang
mesh_terms: D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D003433:Crosses, Genetic; D017343:Genes, Plant; D008040:Genetic Linkage; D005819:Genetic Markers; D008957:Models, Genetic; D010641:Phenotype; D040641:Quantitative Trait Loci; D003313:Zea mays / Q000235:genetics* / Q000254:growth & development
chemical_list: D005819:Genetic Markers