Mapping QTLs for potassium-deficiency tolerance at the seedling stage in wheat (Triticum aestivum L.)

Potassium (K) deficiency is a major factor limiting crop development and yield. In this study, 20 traits were investigated at the seedling stage using a doubled-haploid population subjected to normal K and K deprivation treatments. Evaluation of phenotypes expressed under the two K supply conditions revealed that K deprivation was able to decrease values of ten measured traits, whereas values of the other ten traits increased. A total of 65 QTLs were detected across all 21 chromosomes, except for chromosomes 2B, 5A, and 7B. Individual QTLs in the two K supply treatments explained between 5.35 and 39.64 % of the phenotypic variation. Nine QTL clusters (C1-C9) involving 34 QTLs under the different K supply treatments were mapped to chromosomes 1A, 1B, 1D, 3B, 4A, 5B, 6A, and 7B. Our results are helpful for understanding the genetic basis of K deficiency in wheat, and provide useful information for genetic improvement of K deficiency in wheat by marker-assisted selection.