Periodic Reporting for period 3 - TRANSFER (Edaphic adaptation in barley wild relatives and its transfer to the domesticate)
Reporting period: 2024-02-01 to 2025-07-31
Wild plants can contribute valuable genes to their domesticated relatives. Fertility barriers and a lack of genomic resources have hindered the effective use of crop wild relatives in breeding. The ERC TRANSFER project aims at unraveling the molecular basis of adaptation to saline soils in wild Hordeum species from South America and to use this knowledge to transfer salinity tolerance to domesticated barley. Towards these aims, we are establishing a genomic framework for effective gene isolation and population genomic analysis in barley wild relatives. We hypothesize that differences in salt tolerance are an important driver of ecological differentiation in this group of species and expect genome analysis to reveal the molecular footprints of selection for salt tolerance. Genetic work with experimental populations will resolve the genetic underpinnings to discrete genetic factor. This could potentially deliver specific targets for genetic engineering of cultivated barley varieties. The ERC TRANSFER project will develop and implement a concept for mobilizing the tertiary gene pool of a crop species for pre-breeding efforts. Our specific aims are to
(i) develop a genomics toolbox comprising genome assemblies, genetic maps and targeted mutagenesis for a species complex of barley wild relatives from Patagonia;
(ii) understand the interplay of speciation, adaptation and genomic features such as recombination rates and structural variation by population genomic analyses;
(iii) identify loci and genes involved in adaptation to saline soils by means of genetic mapping, and explore their transferability between species to improve salt tolerance in domesticated barley.
(i) develop a genomics toolbox comprising genome assemblies, genetic maps and targeted mutagenesis for a species complex of barley wild relatives from Patagonia;
(ii) understand the interplay of speciation, adaptation and genomic features such as recombination rates and structural variation by population genomic analyses;
(iii) identify loci and genes involved in adaptation to saline soils by means of genetic mapping, and explore their transferability between species to improve salt tolerance in domesticated barley.
Together with international collaborators, we are in the process of developing a pangenome of barley wild relatives in the genus Hordeum. A pangenome is a collection of genome sequences. By comparing the genomes of different species, we can find evolutionary species that may give us clues about how species arise, how they adapt to different environmental conditions, and if closely related species exchange genes. We have also developed an experimental population that is composed of offspring from a cross between two barley wild relatives that differ in their tolerance to saline soils. We are using genetic and molecular methods to pinpoint the causal genetic factor of differences in salinity tolerance between the parents.
We have taken advantage of recent technological progress in DNA sequencing. The read-out of DNA sequencing machines has improved in length and accuracy in the past three years. This has made it possible to assemble genome sequences for numerous barley wild relatives, something that was not technically feasible only five years ago. By the end of the project, we will have completed the comparative analysis of the Hordeum pangenome and have a deeper understanding of the evolutionary forces at work in the genus. Genetic experiments and analyses will have taught us about the genetic underpinnings of salt tolerance in barley wild relatives from South America.