Inheritance of Cadmium Concentration in Five Durum Wheat Crosses

Abstract

High cadmium concentration in cereal grains has been cited as a human health concern. Several reports showed that grain cadmium concentration was higher in durum (Triticinn turgidum L. var. durum) than in common wheat (T. aestivum L.). The objective of this research was to determine the inheritance of observed differences in grain cadmium concentration of durum wheat. This information could be used to facilitate breeding of cultivars with low grain cadmium concentration. Grain cadmium concentration was determined in the F2 and in F2:3 families of one cross and in F2:3 and F3:4 families of two crosses. Grain and leaf cadmium concentration was measured in random F8:9 and F8:10 families of three crosses. All trials were conducted in the field on Aridic Haploborall, Vertic Cryoborall, or Gleyed Black soils. Grain cadmium concentration was largely controlled by a single gene, with low cadmium dominant. Leaf cadmium concentration was highly correlated with grain cadmium concentration (r = 0.87–0.89, P < 0.01). Therefore, leaf cadmium concentration can predict the plant phenotype, which would be useful in backcrossing the low cadmium trait into high cadmium cultivars. Heritability in standard units, estimated by F2:3 progeny regression on F2 parent or F2:4 progeny regression on F2:3 parent, ranged from 0.84 ± 0.06 to 0.88 ± 0.08, indicating that breeding of low grain cadmium cultivars is feasible. Heritability estimated from variance components (years, locations, replications, and genotypes) was 0.78, with 90% confidence limits of 0.88 and 0.67. The simple inheritance and high heritability of grain cadmium concentration will facilitate the breeding of low cadmium concentration durum cultivars.