Identification and Validation of a New Source of Low Grain Cadmium Accumulation in Durum Wheat

Abstract

Cadmium (Cd) is a heavy metal that has no known biological function and is toxic for many living organisms. The maximum level of Cd concentration allowed in the international market for wheat grain is 0.2 mg kg−1. Because phenotyping for Cd uptake is expensive and time consuming, molecular markers associated with genes conferring low Cd uptake would expedite selection and lead to the development of durum cultivars with reduced Cd concentrations. Here, we identified single nucleotide polymorphisms (SNPs) associated with a novel low Cd uptake locus in the durum experimental line D041735, which has hexaploid common wheat in its pedigree. Genetic analysis revealed a single major QTL for Cd uptake on chromosome arm 5BL within a 0.3 cM interval flanked by SNP markers. Analysis of the intervening sequence revealed a gene with homology to an aluminum-induced protein as a candidate gene. Validation and allelism tests revealed that the low Cd uptake gene identified in this study is different from the closely linked Cdu1-B gene, which also resides on 5BL. This study therefore showed that the durum experimental line D041735 contains a novel low Cd uptake gene that was likely acquired from hexaploid wheat.

Novel quantitative trait loci for low grain cadmium concentration in common wheat (<i>Triticum aestivum</i> L.)

“…5AL in a region homeologous to the Cdu1 locus by using genome-wide association scans. Recently, Oladzad-Abbasabadi et al (2018) reported that a novel locus for Cd uptake in grain (Cdu2-B), which was transferred from common wheat into the durum wheat background, is close to (Miyadate et al 2011, Sasaki et al 2014, Satoh-Nagasawa et al 2012, Ueno et al 2010, Yamaji et al 2013. In durum wheat, TdHMA3-B1, which is located within a 0.14 cM interval on Chr.…”

Breeding for low cadmium accumulation cereals

“…Recently, molecular breeding approaches have accelerated progress in breeding low-Cd cultivars by exploiting technologies such as marker-assisted selection, allele discovery, allele pyramiding, genome mutation, genome selection, genome-wide association mapping, and gene editing. The adoption of novel technologies, such as genetic modification, markerassisted selection, and gene editing, has received increasing interest (Randhawa et al, 2013;Oladzad-Abbasabadi et al, 2018). Furthermore, the successful integration of molecular breeding with conventional breeding methods will accelerate the development of low-Cd cultivars.…”

“…Thus, more attention and effort have been paid to breeding low-Cd durum wheat than bread wheat. Several dozen low-Cd durum wheat cultivars have been identified worldwide (Eriksson, 1990;Grant et al, 2008;Arduini et al, 2014;Zimmerl et al, 2014;Kubo et al, 2016;Perrier et al, 2016;Hirzel et al, 2017Hirzel et al, , 2018Vergine et al, 2017;Oladzad-Abbasabadi et al, 2018;Yue et al, 2018).…”

Breeding Low-Cadmium Wheat: Progress and Perspectives

“…Different categories of molecular markers were used for tagging the marker-QTL of Cd resistance in wheat (Table 2). A major QTL (designated QCdu.ndsu-5B) of Cd uptake on chromosome arm 5BL within a 0.3 cM distance in durum wheat was identified with SNP markers [77]. Similarly, Penner et al (1995) detected a dominant random amplified polymorphic DNA (RAPD) marker (OPC-20) for low Cd uptake in western Canadian durum wheat [88].…”

“…The recent advancements in molecular genetics knowledge have established many modern breeding methods to confer Cd resistance in wheat. Progress in wheat against Cd stress continues by exploiting molecular breeding tools, such as marker-assisted selection, allele discovery, allele pyramiding, genome mutation, association mapping, genome selection, and next-generation sequencing [77]. Currently, there are two key molecular approaches to assess Cd stress in wheat: marker-assisted selection and genomic selection [78].…”