Introducing Beneficial Alleles from Plant Genetic Resources into the Wheat Germplasm

Abstract

Wheat (Triticum sp.) is one of the world’s most important crops, and constantly increasing its productivity is crucial to the livelihoods of millions of people. However, more than a century of intensive breeding and selection processes have eroded genetic diversity in the elite genepool, making new genetic gains difficult. Therefore, the need to introduce novel genetic diversity into modern wheat has become increasingly important. This review provides an overview of the plant genetic resources (PGR) available for wheat. We describe the most important taxonomic and phylogenetic relationships of these PGR to guide their use in wheat breeding. In addition, we present the status of the use of some of these resources in wheat breeding programs. We propose several introgression schemes that allow the transfer of qualitative and quantitative alleles from PGR into elite germplasm. With this in mind, we propose the use of a stage-gate approach to align the pre-breeding with main breeding programs to meet the needs of breeders, farmers, and end-users. Overall, this review provides a clear starting point to guide the introgression of useful alleles over the next decade.

Evolution and origin of bread wheat

“…Moreover, the initial process of domestication might have taken approximately 2–3,000 years ( Kislev, 1984 ; Tanno and Willcox, 2006 ) as seen from the archeological records where fragile, partly fragile, and nonfragile spikes can be found in the same farming sites, providing high chances to hybridize. Consistent with these biological and archeological data, the variation in the domesticated-emmer genome includes ∼73% of that of wild emmer ( Zhou et al, 2020 ; Keilwagen et al, 2022 ; Sharma et al, 2021 ). Genotyping of T. aestivum landraces has shown that a significant part of the variation in wild or domesticated tetraploid wheat has also found its way into the A and B subgenomes of the bread wheat genome suggesting that there was only a limited genetic barrier between tetraploid and hexaploid wheat ( Dvorak et al, 2006 ).…”

“…aestivum , which is of global importance, the other subspecies being only locally cultivated, and we refer to it as bread wheat. In this review, we follow Mac Key’s classification, yet additional classifications were proposed as summarized by Sharma et al (2021) .…”

Detecting major introgressions in wheat and their putative origins using coverage analysis

“…Publicly available data were downloaded from 65 https://doi.org/10.5447/IPK/2019/18 . Additional genomic data was downloaded from EMBL ENA with the following IDs: ERR2936519 and ERR2936122 (GBS data of cv.…”

“…Sometimes the published information is incorrect or misleading. In this study, we consider the taxon names used by Sharma et al 65 . However, we cannot change existing database entries.…”

“…However, we cannot change existing database entries. Overviews of most important wheat and Aegilops classifications can be found in recently published literature 65 .…”