title: Genetic dissection of seed weight by QTL analysis and detection of allelic variation in Indian and east European gene pool lines of Brassica juncea.
abstract: Seed weight QTL identified in different populations were synthesized into consensus QTL which were shown to harbor candidate genes by in silico mapping. Allelic variation inferred would be useful in breeding B. juncea lines with high seed weight. Seed weight is an important yield influencing trait in oilseed Brassicas and is a multigenic trait. Among the oilseed Brassicas, Brassica juncea harbors the maximum phenotypic variation wherein thousand seed weight varies from around 2.0 g to more than 7.0 g. In this study, we have undertaken quantitative trait locus/quantitative trait loci (QTL) analysis of seed weight in B. juncea using four bi-parental doubled-haploid populations. These four populations were derived from six lines (three Indian and three east European lines) with parental phenotypic values for thousand seed weight ranging from 2.0 to 7.6 g in different environments. Multi-environment QTL analysis of the four populations identified a total of 65 QTL ranging from 10 to 25 in each population. Meta-analysis of these component QTL of the four populations identified six 'consensus' QTL (C-QTL) in A3, A7, A10 and B3 by merging 33 of the 65 component Tsw QTL from different bi-parental populations. Allelic diversity analysis of these six C-QTL showed that Indian lines, Pusajaikisan and Varuna, hold the most positive allele in all the six C-QTL. In silico mapping of candidate genes with the consensus QTL localized 11 genes known to influence seed weight in Arabidopsis thaliana and also showed conserved crucifer blocks harboring seed weight QTL between the A subgenomes of B. juncea and B. rapa. These findings pave the way for a better understanding of the genetics of seed weight in the oilseed crop B. juncea and reveal the scope available for improvement of seed weight through marker-assisted breeding.
authors.affiliation: Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
authors.forename: Namrata
authors.initials: N
authors.lastname: Dhaka
authors.affiliation: Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
authors.forename: Kadambini
authors.initials: K
authors.lastname: Rout
authors.affiliation: Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
authors.forename: Satish K
authors.initials: SK
authors.lastname: Yadava
authors.affiliation: Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
authors.forename: Yaspal Singh
authors.initials: YS
authors.lastname: Sodhi
authors.affiliation: Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
authors.forename: Vibha
authors.initials: V
authors.lastname: Gupta
authors.affiliation: Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
authors.forename: Deepak
authors.initials: D
authors.lastname: Pental
authors.affiliation: Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India. pradhancgmcp@gmail.com.|Centre for Genetic Manipulation of Crop Plants, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India. pradhancgmcp@gmail.com.
authors.forename: Akshay K
authors.initials: AK
authors.lastname: Pradhan
mesh_terms: D000483:Alleles; D002874:Chromosome Mapping; D016384:Consensus Sequence; D004843:Epistasis, Genetic; D005788:Gene Pool; D005828:Genetics, Population; D006238:Haploidy; D009149:Mustard Plant / Q000235:genetics* / Q000254:growth & development; D010641:Phenotype; D040641:Quantitative Trait Loci; D012639:Seeds / Q000235:genetics / Q000254:growth & development*