Introgression Breeding in Barley: Perspectives and Case Studies

Abstract

Changing production scenarios resulting from unstable climatic conditions are challenging crop improvement efforts. A deeper and more practical understanding of plant genetic resources is necessary if these assets are to be used effectively in developing improved varieties. In general, current varieties and potential varieties have a narrow genetic base, making them prone to suffer the consequences of new and different abiotic and biotic stresses that can reduce crop yield and quality. The deployment of genomic technologies and sophisticated statistical analysis procedures has generated a dramatic change in the way we characterize and access genetic diversity in crop plants, including barley. Various mapping strategies can be used to identify the genetic variants that lead to target phenotypes and these variants can be assigned coordinates in reference genomes. In this way, new genes and/or new alleles at known loci present in wild ancestors, germplasm accessions, land races, and unadapted introductions can be located and targeted for introgression. In principle, the introgression process can now be streamlined and linkage drag reduced. In this review, we present an overview of (1) past and current efforts to identify diversity that can be tapped to improve barley yield and quality, and (2) case studies of our efforts to introgress resistance to stripe and stem rust from un-adapted germplasm. We conclude with a description of a modified Nested Association Mapping (NAM) population strategy that we are implementing for the development of multi-use naked barley for organic systems and share perspectives on the use of genome editing in introgression breeding.

Genetic Diversity for Agronomic Traits and Phytochemical Compounds in Coloured Naked Barley Lines

“…For the agronomic traits, the lowest heritability was recorded for seed yield in our experiment, perhaps because yield is a character controlled by many genes. Moreover, as reported by Hernandez et al [ 14 ], the progress in selection for this trait is, in general, slow due to the masking effect of the environment and to a narrow germplasm base in barley. Furthermore, according to Yadav et al [ 20 ], we found a high heritability and a moderate genetic advance for the days to heading and thousand seed weight.…”

“…Nowadays, very few naked barley cultivars have been developed for modern European and North American agricultural systems [ 13 ]. The introgression of the naked phenotype is currently an interesting goal of breeding to develop naked multi-use barley lines for conventional and organic systems [ 14 ].…”

EoRNA, a barley gene and transcript abundance database

“…It is a widely studied crop model with abundant genetic resources that include diverse natural cultivated, wild and landrace collections, experimentally constructed populations, introgression and mutant lines. Its robust diploid genetics are supported by numerous high-resolution linkage maps and fully sequenced reference and pan-genome sequences (1, 2, 3, 4, 5). Genomic diversity has contributed to barley being grown worldwide, producing harvestable yields under a broad range of environmental conditions and climates (1, 4, 6).…”

Comportamiento productivo y estabilidad fenotípica de Hordeum vulgare L. en Colombia

“…Estos resultados abren la posibilidad de reorganizar el programa de mejoramiento con la tropicalización de la cebada, mediante la hibridación intraespecífica con énfasis en incrementar el potencial productivo y mejorar la calidad industrial del grano en las variedades locales antiguas. Esta estrategia, se utiliza con éxito con la introgresión (hibridación interespecífica) de germoplasma tropical del maíz en el temperado para mejorar adaptación en el trópico (Cairns & Prasanna, 2018) y en cebada para ampliar la base genética y la adaptación a estreses abióticos y la calidad (Hernandez et al, 2020).…”