title: Forward and reverse genetics of rapid-cycling Brassica oleracea.
abstract: Seeds of rapid-cycling Brassica oleracea were mutagenized with the chemical mutagen, ethylmethane sulfonate. The reverse genetics technique, TILLING, was used on a sample population of 1,000 plants, to determine the mutation profile. The spectrum and frequency of mutations induced by ethylmethane sulfonate was similar to that seen in other diploid species such as Arabidopsis thaliana. These data indicate that the mutagenesis was effective and demonstrate that TILLING represents an efficient reverse genetic technique in B. oleracea that will become more valuable as increasing genomic sequence data become available for this species. The extensive duplication in the B. oleracea genome is believed to result in the genetic redundancy that has been important for the evolution of morphological diversity seen in today's B. oleracea crops (broccoli, Brussels sprouts, cauliflower, cabbage, kale and kohlrabi). However, our forward genetic screens identified 120 mutants in which some aspect of development was affected. Some of these lines have been characterized genetically and in the majority of these, the mutant trait segregates as a recessive allele affecting a single locus. One dominant mutation (curly leaves) and one semi-dominant mutation (dwarf-like) were also identified. Allelism tests of two groups of mutants (glossy and dwarf) revealed that for some loci, multiple independent alleles have been identified. These data indicate that, despite genetic redundancy, mutation of many individual loci in B. oleracea results in distinct phenotypes.
authors.affiliation: Department of Biology, California Polytechnic State University, San Luis Obispo, CA 93407, USA. ehimelbl@calpoly.edu
authors.forename: Edward
authors.initials: E
authors.lastname: Himelblau
authors.forename: Erin J
authors.initials: EJ
authors.lastname: Gilchrist
authors.forename: Kelly
authors.initials: K
authors.lastname: Buono
authors.forename: Colleen
authors.initials: C
authors.lastname: Bizzell
authors.forename: Laurie
authors.initials: L
authors.lastname: Mentzer
authors.forename: Robert
authors.initials: R
authors.lastname: Vogelzang
authors.forename: Thomas
authors.initials: T
authors.lastname: Osborn
authors.forename: Richard M
authors.initials: RM
authors.lastname: Amasino
authors.forename: Isobel A P
authors.initials: IA
authors.lastname: Parkin
authors.forename: George W
authors.initials: GW
authors.lastname: Haughn
mesh_terms: D000483:Alleles; D017360:Arabidopsis / Q000033:anatomy & histology / Q000235:genetics; D001937:Brassica / Q000033:anatomy & histology / Q000235:genetics*; D019143:Evolution, Molecular; D020440:Gene Duplication; D017343:Genes, Plant; D005821:Genetic Techniques; D005875:Gibberellins / Q000494:pharmacology; D016296:Mutagenesis; D010641:Phenotype; D010936:Plant Extracts / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology; D018515:Plant Leaves / Q000648:ultrastructure; D036226:Seedlings / Q000187:drug effects; D012639:Seeds / Q000235:genetics* / Q000378:metabolism
chemical_list: D005875:Gibberellins; D010936:Plant Extracts; D010937:Plant Growth Regulators; C007842:gibberellic acid