Expansion Of QW DH Population And QTL Mapping For Boron Efficiency At Seedling In Brassica Napus

Brassica napus needs more boron for its growth, its place in a serious lack of boron regions in our country, boron deficiency seriously affects yield and quality. Boron is non-renewable resources, so we have to develop methods for genetic improvement through boron efficient varieties. A double haploid population named QW DH226was derived from the F1progeny of a cross between B-inefficient parent WestarlO and B-effcient parent Qingyou10by microspore culture, and a genetic linkage map was constructed by screening a number of SSR markers in the QW DH226population. Hydroponics experiment using the QW DH226population was conducted. Quantitative trait locus (QTL) analysis for B-efficiency associated traits under both B conditions at seedling stage was carried on. Please pay attention to these main results:1. Expansion of QW DH:Based on the YingYingLi build QW DH, we used for microspore culture, and155DH lines were gained. A B-efficient double haploid population QW DH226comprising226lines combining with71DH lines of the previous QW DH population by Yingying Li was constructed.2. Construction of QW DH226genetic linkage framework map:The genetic linkage framework map was constructed based on the QW DH226population and spanned19linkage groups corresponding to19chromosomes in B. napus named as A1-A10and C1-C9using SSR molecular markers by JionMap4.0. The QW DH226map comprising a total of210molecular markers covers a total of length of2064.41cM with an average length of9.83cM.3. Analyzing biomass-related traits and B concentration-related associated with B-efficiency:By solution culture, fresh weight、root length dry weight、B accumulation、B concentration were investigated among Qingyou10、WestarlO and QW DH226population.Obvious, at low levels of boron, boron efficient parental QY10increase in root length, fresh weight, dry weighe were significantly higher than the cumulative boron inefficient parentl Weatar10; while the boron content of the roots, efficient parental no significant advantage. Obvious differences among the double haploid population were tested and found both B conditions transgressive segregation.4. Mapping QTLs for B-efficiency at seedling stage:A total of42significant QTLs for18traits were identified disbuting in11linkage groups using WinQTLCart2.5software under normal and low B conditions, singly explaining5.91-15.20%of phenotypic variation. LOD values of the QTLs ranged from3.02to7.79. Common use of genetic markers on the map, find QW DH and QW DH226in the same chromosome between the markers have the same QTL loci, and the positioning control on the chromosome C4biomass and root length related traits QTL clusters with boron efficient in the same locus BnBE2interval.