title: Gene networks in hexaploid wheat: interacting quantitative trait loci for grain protein content.
abstract: In hexaploid wheat, single-locus and two-locus quantitative trait loci (QTL) analyses for grain protein content (GPC) were conducted using two different mapping populations (PI and PII). Main effect QTLs (M-QTLs), epistatic QTLs (E-QTLs) and QTL x environment interactions (QE, QQE) were detected using two-locus analyses in both the populations. Only a few QTLs were common in both the analyses, and the QTLs and the interactions detected in the two populations differed, suggesting the superiority of two-locus analysis and the need for using several mapping populations for QTL analysis. A sizable proportion of genetic variation for GPC was due to interactions (28.59% and 54.03%), rather than to M-QTL effects (7.24% and 7.22%), which are the only genetic effects often detected in the majority of QTL studies. Even E-QTLs made a marginal contribution to genetic variation (2.68% and 6.04%), thus suggesting that the major part of genetic variation is due to changes in gene networks rather than the presence or absence of specific genes. This is in sharp contrast to the genetic dissection of pre-harvest sprouting tolerance conducted by us earlier, where interaction effects were not substantial, suggesting that the nature of genetic variation also depends on the nature of the trait.
authors.affiliation: Molecular Biology Laboratory, Department of Genetics and Plant Breeding, Ch. Charan Singh University, Meerut, Uttar Pradesh, 250 004, India.
authors.forename: Pawan
authors.initials: P
authors.lastname: Kulwal
authors.forename: Neeraj
authors.initials: N
authors.lastname: Kumar
authors.forename: Ajay
authors.initials: A
authors.lastname: Kumar
authors.forename: Raj Kumar
authors.initials: RK
authors.lastname: Gupta
authors.forename: Harindra Singh
authors.initials: HS
authors.lastname: Balyan
authors.forename: Pushpendra Kumar
authors.initials: PK
authors.lastname: Gupta
mesh_terms: D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011123:Polyploidy; D040641:Quantitative Trait Loci; D014908:Triticum / Q000235:genetics* / Q000378:metabolism
chemical_list: D010940:Plant Proteins