title: Molecular-cytogenetic characterization of C-genome chromosome substitution lines in Brassica juncea (L.) Czern and Coss.
abstract: C genome chromosome substitution lines of B. juncea constitute a key genetic resource for increased genetic diversity and hybrid performance. C genome chromosome substitution lines were found in the progenies of derived B. juncea (2n = 36; AABB), synthesized through hybridization between B. napus and B. carinata. These were originally recognized based on the morphology and genomic in situ hybridization. Genotyping using the Brassica Illumina 60K Infinium SNP array confirmed the presence of C genome chromosomes in a large number of derived B. juncea genotypes. Three whole chromosome substitutions and 13 major C genome fragment substitutions were identified. Fragment substitutions were primarily terminal, but intercalary substitution(s) involving chromosome C1 and C2 were identified in three genotypes. The size of substituted C genome fragments varied from 0.04 Mbp (C1) to 64.85 Mbp (C3). In terms of proportions, these ranged from 0.10 % (C1) to 100 % (C1, C3 and C7) of the substituted chromosome. SSR genotyping with B genome specific primers suggested that substituting C genome chromosome(s) are likely to have replaced B genome chromosome(s). C1 was the most common substituting chromosome while substituted B chromosome seemed random. Study of the phenotypic traits underlined the importance of the substitution lines (especially of chromosome C1) for conferring superior trait performance (main shoot length and pods on the main shoot). High heterosis was also indicated in hybrid combinations of substitution lines with natural B. juncea. These substitution genotypes constituted a valuable resource for targeted gene transfer and QTL identification.
authors.affiliation: Department of Plant Breeding and Genetics, DBT Centre of Excellence on Brassicas, Punjab Agricultural University, Ludhiana, 141001, India.
authors.forename: Mehak
authors.initials: M
authors.lastname: Gupta
authors.affiliation: School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD, 4072, Australia.|Department of Plant Breeding, Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany.
authors.forename: Annaliese S
authors.initials: AS
authors.lastname: Mason
authors.affiliation: School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD, 4072, Australia.|School of Plant Biology, University of Western Australia, Crawley, WA, 6009, Australia.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Batley
authors.affiliation: Department of Plant Breeding and Genetics, DBT Centre of Excellence on Brassicas, Punjab Agricultural University, Ludhiana, 141001, India.
authors.forename: Sakshi
authors.initials: S
authors.lastname: Bharti
authors.affiliation: Department of Plant Breeding and Genetics, DBT Centre of Excellence on Brassicas, Punjab Agricultural University, Ludhiana, 141001, India.
authors.forename: Shashi
authors.initials: S
authors.lastname: Banga
authors.affiliation: Department of Plant Breeding and Genetics, DBT Centre of Excellence on Brassicas, Punjab Agricultural University, Ludhiana, 141001, India. nppbg@pau.edu.
authors.forename: Surinder S
authors.identifier: http://orcid.org/0000-0001-8209-7341
authors.initials: SS
authors.lastname: Banga
mesh_terms: D032461:Chromosomes, Plant / Q000235:genetics*; D018744:DNA, Plant / Q000235:genetics; D014644:Genetic Variation; D018745:Genome, Plant; D005838:Genotype; D006823:Hybrid Vigor; D006824:Hybridization, Genetic; D017404:In Situ Hybridization, Fluorescence; D009149:Mustard Plant / Q000235:genetics*; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide
chemical_list: D018744:DNA, Plant