Potassium (K) effects and QTL mapping for K efficiency traits at seedling and adult stages in wheat

Abstract

Potassium (K) is one of the most important mineral nutrients limiting plant growth in agricultural systems. This study investigated the effects of low-K treatments and detected quantitative trait loci (QTLs) for K efficiency traits at the seedling and adult stages of wheat. Eleven seedling traits under a hydroponic culture trial with five K treatments and nine adult traits in a pot trial and a field trial with three K treatments were investigated using a set of wheat recombinant inbred lines (RILs). Values of most of the seedling and adult traits decreased with decreasing K supply, but the K-use efficiency and ratio of dry weight between seedling roots and shoots (RSDW) increased. A total of 87 QTLs for seedling traits in the hydroponic culture trial and 51 and 29 QTLs for adult traits in the pot and field trials, respectively, were detected. We also identified 15 relatively high-frequency QTLs (RHF-QTLs) which can be detected in over half of the treatments and 21 QTL clusters which is defined as the co-location of QTLs for more than two traits. K efficiency traits and the related QTLs of wheat were greatly affected by K treatments. Several relatively stable QTLs and important QTL clusters may be potential targets for marker-assisted selection for wheat nutrient efficiency.