Genetic Properties of a Nested Association Mapping Population Constructed With Semi-Winter and Spring Oilseed Rapes

Genetic Properties of a Nested Association Mapping Population Constructed With Semi-Winter and Spring Oilseed Rapes

Blog Article

Nested association mapping (NAM) populations have been widely applied to dissect the genetic basis of complex quantitative traits in a variety of crops.In this study, we developed a Brassica napus NAM (BN-NAM) population consisting of 15 recombination inbred line (RIL) families with 2,425 immortal genotypes.Fifteen high-density genetic linkage maps were constructed by genotyping by sequencing (GBS) based on all RIL families, with further integration into a joint epicenter mini linkage map (JLM) having 30,209 unique markers in common with multiple linkage maps.

Furthermore, an ultra-density whole-genome variation map was constructed by projecting 4,444,309 high-quality variants onto the JLM.The NAM population captured a total of 88,542 recombination events (REs).The uneven distribution of recombination rate along chromosomes is positively correlated with equi-jec 6 the densities of genes and markers, but negatively correlated with the density of transposable elements and linkage disequilibrium (LD).

Analyses of population structure and principal components revealed that the BN-NAM population could be divided into three groups with weak stratification.The LD decay distance across genome varied between 170 and 2,400 Kb, with LD decay more rapid in the A than in the C sub-genome.The pericentromeric regions contained large LD blocks, especially in the C sub-genome.

This NAM population provides a valuable resource for dissecting the genetic basis of important traits in rapeseed, especially in semi-winter oilseed rape.