Crop wild relatives in durum wheat breeding: Drift or thrift?

Abstract

Crop wild relatives (CWRs) are an important source of genetic diversity for crop improvement. The aim of this study was to assess the usefulness of deploying CWRs in durum wheat [Triticum turgidum L. subsp. durum (Desf.) van Slageren] breeding. A set of 60 accessions was selected to include cultivars from nine countries, top lines obtained via elite-by-elite crossing, and CWR-derived lines. These accessions were screened for resistance against four major fungal diseases to reveal that CWR-derived lines are a good source of resistance against Septoria leaf blotch (Zymoseptoria tritici), while they were highly susceptible to tan spot (Pyrenophora tritici-repentis). Drought tolerance was assessed at eight environments with contrasting nitrogen levels and tillage practices to reveal a clear superiority of CWR-derived lines for grain size as well as higher grain yield (GY) under low nitrogen and normal tillage (NT). Temperature-stress tolerance was assessed at four heat-stressed environments along the Senegal River to confirm CWR-derived had up to 42% yield advantage and a higher grain number per spike (GNspk). Combined testing under plastic heat tunnels imposed at the time of flowering also revealed good performance of CWR-derived lines. However, the CWR-derived lines had low gluten sedimentation index and poor yellow color compared with cultivars and elite germplasm. High genetic diversity was found in CWR-derived lines with 75% of individuals having minor allele frequency (MAF) of 40-44% for frequent alleles but low genetic diversity for alleles with low frequency. In addition, 8-13% of the CWR parent genome

Small “Nested” Introgressions from Wild Thinopyrum Species, Conferring Effective Resistance to Fusarium Diseases, Positively Impact Durum Wheat Yield Potential

“…Based on the observed results, there may well be a complex network of interactions between environmentally modulated “wild” and “cultivated” factors of both genetic and epigenetic nature. Such factors were similarly contemplated to explain the novel phenotypes exhibited by cultivated germplasm, containing alien/wild introgressions (e.g., [ 28 , 61 ]). In addition to these direct effects on yield, an indirect contributing asset is provided to the novel RLs by the introduced genes/QTL for resistance against leaf rust ( Lr19 ) as well as Fusarium threats, i.e., FHB and FCR ( Fhb7el 2 and Fhb7E ).…”

The Global Durum Wheat Panel (GDP): An International Platform to Identify and Exchange Beneficial Alleles

“…Therefore, breeders are devoting increasing resources and effort to identify beneficial alleles and traits from novel germplasm sources to reinvigorate their programs. Indeed, pre-breeding activities have been pursued by international programs at ICARDA ( Zaïm et al, 2017 ; Bassi et al, 2019 ; Robbana et al, 2019 ; El Haddad et al, 2020 ) and CIMMYT ( Singh et al, 2018 ; Ledesma-Ramírez et al, 2019 ), and by national research institutes to introgress beneficial alleles from landraces and wild relatives, in parallel to international initiatives which aim to identify, collect, conserve and use the wild cousins of some of the most important food crops, as the CWR project “Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives 1 . Population structure and genetic diversity have been studied in several modern and landrace collections of durum wheat.…”

The 55K SNP-Based Exploration of QTL for Spikelet Number Per Spike in a Tetraploid Wheat (Triticum turgidumL.) Population: Chinese Landrace ‘Ailanmai’ × Wild Emmer

“…Nonetheless, common wheat breeding reduces the genetic diversity among elite germplasm resources, thus adversely affecting wheat yield (Cavanagh et al, 2013; Sthapit et al, 2020). Notably, the numerous genetic resources for agronomic traits and disease resistance from wheat related species may effectively solve future wheat production challenges (Zaïm et al, 2017; El Haddad et al, 2021). As the progenitor of modern cultivated tetraploid and hexaploid wheat, wild emmer wheat ( T .…”