A Major QTL Controlling Seed Cadmium Accumulation in Soybean

Abstract

ABSTRACTCadmium (Cd) is a pollutant heavy metal that is naturally present in soils and highly toxic to biological organism even at low concentrations. Significant differences were observed among soybean [Glycine max (L.) Merr.] cultivars in the uptake of Cd by root and its posterior translocation to the shoot and grain. The aim of this research was to identify quantitative trait loci (QTLs) for seed Cd concentration in soybean. A single population derived from a cross between the cultivars Harosoy and Fukuyutaka, which differ in seed Cd levels, were used for QTL analysis. The population consisted of 93 F5:6 recombinant inbred lines (RILs), 93 F6:7 RILs, 93 F7:8 RILs, and 100 F6:7 near‐isogenic lines (NILs). A total of 220 simple sequence repeat (SSR) markers were genetically mapped on the 93 F5:6 RILs population and clustered into 22 molecular linkage groups (MLGs) which covered a genetic distance of approximately 2400 centimorgans (cM). Analysis revealed one major QTL (cd1) on Chromosome 9 (MLG K) associated with seed Cd concentration. The cd1 was stable across years–generations and accounted for 82, 57, and 75% of the genetic variation in the RILs populations tested in the field. Effect of cd1 was verified by means of a NIL population developed from the F5:6 RILs. The followup survey results indicated that the novel SSR markers Gm09: 4770663 and Gm09: 4790483 assigned to MLG K seemed to be suitable markers for selecting genotypes with low seed Cd concentration in soybean.