Identification of quantitative trait loci associated with tolerance to low potassium and related ions concentrations at seedling stage in rice (Oryza sativa L.)

Potassium (K) is one of the essential macronutrients of rice growth and eventually affects yields. To investigate the genetics of low K tolerance and related ions concentrations at the seedling stage in rice, quantitative trait loci (QTLs) were detected using a doubled haploid population derived from a cross between a japonica cultivar CJ06 and an indica accession TN1. A total of 96 QTLs were identified with phenotypic variation 5-29 %, including 30 QTLs found to be associated with shoot height, root length, shoot dry weight, root dry weight and total dry weight under the control (40 mg L-1 K+) and low K stress conditions (4 mg L-1 K+), 14 putative QTLs associated with the K tolerance coefficient of all examined traits and synthetic appraisal index, and 52 QTLs controlling four ions (Na+, K+, Ca2+ and Mg2+) concentrations of root and shoot under two treatments. The results indicated that low K tolerance and related ions concentrations were quantitatively inherited, and the detected major QTLs may be useful for marker-assistant selection.