Molecular markers for seed colour in Brassica juncea.
A detailed RFLP map was used to map QTLs associated with seed colour in Brassica juncea using a doubled-haploid population derived from a cross between a black/brown-seeded cultivar and a yellow-seeded breeding line. Segregation analysis suggested that seed colour was under control of 2 unlinked loci with duplicate gene action. However, QTL analysis revealed 3 QTLs, SC-B4, SC-A10 and SC-A6, affecting seed colour. The QTLs were consistent across environments, and individually explained 43%, 31%, and 16%, respectively, and collectively 62% of the phenotypic variation in the population. Digenic interaction analysis showed that closest flanking locus of QTL SC-B4, wg7b6cNM, had strong epistasis with the locus wg5a1a, which is tightly linked to QTL SC-A6. The interaction of these 2 loci explained 27% of the phenotypic variation in the population, while the whole model explained 84%. In a multiple regression model, the effects of QTL SC-A10, as well as its interaction with other loci, were non-significant, whereas the effects of loci wg7b6cNM and wg5a1a and their interaction were significant. Ninety-eight percent of the DH lines carried the expected alleles of loci wg7b6cNM and wg5a1a for seed colour, confirming that only these 2 loci were linked to seed colour in B. juncea. Four additional digenic interactions significantly affected seed colour, and all 5 digenic interactions were consistent across environments.
Mahmood
T
T
Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Canada.
Rahman
M H
MH
Stringam
G R
GR
Raney
J P
JP
Good
A G
AG
D000704:Analysis of Variance; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D004843:Epistasis, Genetic; D005819:Genetic Markers / Q000235:genetics*; D018745:Genome, Plant; D008957:Models, Genetic; D009149:Mustard Plant / Q000235:genetics* / Q000502:physiology; D010641:Phenotype; D010858:Pigmentation / Q000235:genetics*; D040641:Quantitative Trait Loci / Q000235:genetics; D012639:Seeds / Q000235:genetics / Q000502:physiology*
D005819:Genetic Markers