Abstract
Breeding crops that acquire and/or utilize potassium (K) more effectively could reduce the use of K fertilizers. Sixteen traits affecting K use efficiency (KUE) at the seedling stage were investigated in a B. napus double haploid population grown at an optimal K supply (OK) and a low K supply (LK) in a hydroponic culture system. In total, 50 and 62 QTLs associated with these traits were identified at OK and LK, respectively. A total of 25 orthologues of 23 Arabidopsis genes regulating K transport were identified in the confidence intervals of nine QTLs impacting shoot dry weight at LK, and 22 of these showed variations in coding sequences and/or exhibited significant differences in mRNA abundances in roots at LK between the two parental lines. This study provided insights to the genetic basis of KUE in B. napus, which will accelerate the breeding of K-efficient rapeseed cultivars by marker-assisted selection.
•Potassium (K) uptake efficiency correlated with shoot dry weight in B. napus, but K utilization efficiency did not.•Most of the QTLs affecting the same trait differed between K sufficient and deficient conditions.•Τwenty-five candidate genes affecting K transport were identified underlying QTLs for the shoot dry weight under K deficient conditions.•SNP and/or InDels were identified in the coding sequences of 13 candidate genes between two parents that might alter protein function.•Thirteen candidate genes exhibited significant differences in mRNA expression in roots between the two parents under K deficient condition, three of which showed genetic variants in their promoter regions.