Global wheat production is key to feeding humankind, but diseases annually consume an estimated 10% or more of that production. The pathogens most widely undercutting global wheat production are mainly fungal: those causing the three rusts (yellow, brown, and black), Fusarium diseases of spikes and crowns, the foliar blotches, and wheat powdery mildew. In some regions, viruses vectored by arthropods are also damaging; for example, barley yellow dwarf virus and wheat streak mosaic virus. Soilborne viruses and nematodes can also pose significant challenges to wheat production in affected regions.
There are major challenges to breeding more disease-resistant wheat cultivars. With respect to the obligate rust and mildew pathogens, the basic problem is their ability to rapidly overcome the major resistance genes historically deployed against them. Hence, specific pre-breeding and selection strategies must be carefully planned and pursued; they include identification and exploitation of the most effective and durable loci; pyramiding; and accumulation of partial resistance genes. By contrast, Fusarium head blight remains an enormous challenge because the currently deployed resistance genes often do not confer adequate protection against the accumulation of damaging mycotoxins in wheat grain.
Recent molecular and statistical advances in breeding have generated powerful tools for gaining a deeper insight into the genetic architecture of resistance to these diseases, and tackling these disease resistance challenges. In particular, the ability to mine genome-wide associations between genotypes and phenotypes has led to major advances in our ability to utilize resistance alleles with unknown and minor effects. Another area where more investments are needed is the development of dedicated marker-assisted selection (MAS) tools. A current debate is how to switch effectively from single bi-allelic SNP loci to SNP combinations and the selection of haplotypes, which guarantee a more effective MAS. This Research Topic seeks to span the divide between basic and applied aspects of breeding for wheat disease resistance. Broadly, it will address both challenges and success stories: how disease-resistant cultivars are being developed by breeding programs through scientific advances, particularly the application and validation of new breeding tools and new markers.
We will include contributions on sub-topics such as these, although not limited to these:
· The roles that genomic selection and genome-wide association studies are playing in breeding wheat for resistance to wheat diseases
· Advances in characterizing, selecting for, and deploying quantitative disease resistance in wheat
· Application of gene editing to create more disease-resistant wheat cultivars
· Use of RNA silencing mechanisms to silence the targets of wheat pathogens
· Mutagenesis-based techniques for creating desirable variation in disease resistance genes, such as TILLING
Global wheat production is key to feeding humankind, but diseases annually consume an estimated 10% or more of that production. The pathogens most widely undercutting global wheat production are mainly fungal: those causing the three rusts (yellow, brown, and black), Fusarium diseases of spikes and crowns, the foliar blotches, and wheat powdery mildew. In some regions, viruses vectored by arthropods are also damaging; for example, barley yellow dwarf virus and wheat streak mosaic virus. Soilborne viruses and nematodes can also pose significant challenges to wheat production in affected regions.
There are major challenges to breeding more disease-resistant wheat cultivars. With respect to the obligate rust and mildew pathogens, the basic problem is their ability to rapidly overcome the major resistance genes historically deployed against them. Hence, specific pre-breeding and selection strategies must be carefully planned and pursued; they include identification and exploitation of the most effective and durable loci; pyramiding; and accumulation of partial resistance genes. By contrast, Fusarium head blight remains an enormous challenge because the currently deployed resistance genes often do not confer adequate protection against the accumulation of damaging mycotoxins in wheat grain.
Recent molecular and statistical advances in breeding have generated powerful tools for gaining a deeper insight into the genetic architecture of resistance to these diseases, and tackling these disease resistance challenges. In particular, the ability to mine genome-wide associations between genotypes and phenotypes has led to major advances in our ability to utilize resistance alleles with unknown and minor effects. Another area where more investments are needed is the development of dedicated marker-assisted selection (MAS) tools. A current debate is how to switch effectively from single bi-allelic SNP loci to SNP combinations and the selection of haplotypes, which guarantee a more effective MAS. This Research Topic seeks to span the divide between basic and applied aspects of breeding for wheat disease resistance. Broadly, it will address both challenges and success stories: how disease-resistant cultivars are being developed by breeding programs through scientific advances, particularly the application and validation of new breeding tools and new markers.
We will include contributions on sub-topics such as these, although not limited to these:
· The roles that genomic selection and genome-wide association studies are playing in breeding wheat for resistance to wheat diseases
· Advances in characterizing, selecting for, and deploying quantitative disease resistance in wheat
· Application of gene editing to create more disease-resistant wheat cultivars
· Use of RNA silencing mechanisms to silence the targets of wheat pathogens
· Mutagenesis-based techniques for creating desirable variation in disease resistance genes, such as TILLING
