A study on relative importance of additive, epistasis and unmapped QTL for Aluminium tolerance at seedling stage in soybean

Abstract

The relative importance of quantitative trait locus (QTL) types controlling aluminium (Al) tolerance in a recombinant inbred line population of soybean was assessed under greenhouse sand culture in 2years. Three growth-related indicators for Al-tolerance, namely relative total plant dry weight (RTDW), relative shoot dry weight (RSDW) and relative root dry weight (RRDW) were analysed for genetic architecture. RTDW showed relatively higher correlations and shared marker regions with RSDW and RRDW. Four additive QTL, four epistatic QTL pairs and collective unmapped QTL were identified for RTDW, with respective contributions of 22.30%, 14.86% and 40.64%, in a total genetic contribution of 77.80% to phenotypic variation, while QTL×Environment contribution was relatively negligible. Similar results were found for RSDW and RRDW. Altogether, seven additive QTL, eleven epistatic QTL pairs and collective unmapped QTL were involved with Al-tolerance. Among them, one major QTL linked to marker region GMKF046-Sat-128 on B1 was shared by the three traits. The results imply that the three QTL types are all relevant and should be comprehensively utilized for the improvement of Al-tolerance in soybean. © 2011 Blackwell Verlag GmbH.