摘要 : Some durum wheat (<i>Triticum turgidum</i> L. var <i>durum</i>) cultivars have the genetic propensity to accumulate cadmium (Cd) in the grain. A major gene controlling grain Cd concentration designated as <i>Cdu1</i> has been repo... 展开 Some durum wheat (<i>Triticum turgidum</i> L. var <i>durum</i>) cultivars have the genetic propensity to accumulate cadmium (Cd) in the grain. A major gene controlling grain Cd concentration designated as <i>Cdu1</i> has been reported on 5B, but the genetic factor(s) conferring the low Cd phenotype are currently unknown. The objectives of this study were to saturate the chromosomal region harboring <i>Cdu1</i> with newly developed PCR-based markers and to investigate the colinearity of this wheat chromosomal region with rice (<i>Oryza sativa</i> L.) and <i>Brachypodium distachyon</i> genomes. Genetic mapping of markers linked to <i>Cdu1</i> in a population of recombinant inbred substitution lines revealed that the gene(s) associated with variation in Cd concentration resides in wheat bin 5BL9 between fraction breakpoints 0.76 and 0.79. Genetic mapping and quantitative trait locus (QTL) analysis of grain Cd concentration was performed in 155 doubled haploid lines from the cross W9262-260D3 (low Cd) by Kofa (high Cd) revealed two expressed sequence tag markers (ESMs) and one sequence tagged site (STS) marker that co-segregated with <i>Cdu1</i> and explained >80% of the phenotypic variation in grain Cd concentration. A second, minor QTL for grain Cd concentration was also identified on 5B, 67 cM proximal to <i>Cdu1</i>. The <i>Cdu1</i> interval spans 286 kbp of rice chromosome 3 and 282 kbp of <i>Brachypodium</i> chromosome 1. The markers and rice and <i>Brachypodium</i> colinearity described here represent tools that will assist in the positional cloning of <i>Cdu1</i> and can be used to select for low Cd accumulation in durum wheat breeding programs targeting this trait. The isolation of <i>Cdu1</i> will further our knowledge of Cd accumulation in cereals as well as metal accumulation in general. 收起