Resistance to wheat rusts identified in wheat/Amblyopyrum muticum chromosome introgressions

Abstract

Wheat (Triticum aestivum L.) rusts are a worldwide production problem. Plant breeders have used genetic resistance to combat these fungi. However, single‐gene resistance is rapidly overcome as a result of frequent occurrence of new virulent fungal strains. Thus, a supply of new resistance sources is continually needed, and new resistance sources are limited within hexaploid wheat genetic stocks. Wild relatives are able to be a resource for new resistance genes but are hindered because of chromosome incapability with domesticated wheats. Twenty‐eight double‐haploid hexaploid wheat/Amblyopyrum muticum (Boiss.) Eig introgression lines, with introgressions covering the majority of the T genome, were evaluated for resistance to Puccinia triticina Erikss., P. graminis Pers.:Pers. f.sp. tritici Erikss. & E. Henning, and P. striiformis Westend. f.sp. tritici Erikss.. At the seedling level, four lines were resistant to races of P. triticina, six lines were resistant to P. graminis, and 15 lines were resistant to P. striiformis. At the adult stage, 16 lines were resistant to P. triticina. Line 355 had resistance to all three rusts and line 161 had resistance to all tested races of P. triticina. Some of these lines will require further work to reduce the size of the introgressed segment; however, lines 92 and 355 have very small fragments and can be used directly as new resistance donors.

Evaluating the Introgression of Wild Germplasm Into Autotetraploid Blueberry Breeding

“…Moreover, as crop pest pressures continue to increase, research into wild species' resistance must continue to meet the escalating pressures that threaten global food production. Notably, wild species can allow for introgression of disease-resistance traits as previously seen in wheat [14], rice [15], and corn [16]. In addition to improved fruit quality and abiotic stress resistance, V. elliottii can also function as a genetic resource for biotic stress resistance.…”

Whole‐genome sequencing uncovers the structural and transcriptomic landscape of hexaploid wheat/Ambylopyrum muticum introgression lines

“…Identifying candidate introgressed genes underlying Am. muticum derived rust resistance Two of the lines that we sequenced, DH92 and DH121 (Figure 5a), have complete resistance at the seedling stage to Kansas isolates of Puccinia striiformis tritici (stripe/yellow rust) (Fellers et al, 2020). DH92 also displays chlorotic adult resistance to leaf rust and partial resistance to stem rust, that is absent in DH121.…”

Whole genome sequencing uncovers the structural and transcriptomic landscape of hexaploid wheat/Ambylopyrum muticum introgression lines

“…This is likely the case for the leaf rust resistance in DH195. DH195 has seedling and adult leaf rust resistance not seen in DH202, DH123, or DH121 (17), all of which have 7D/7T segments. Differences in segment size and position between these lines (fig.…”

“…Phenotypic screening of Am. muticum introgression lines (Fellers et al, 2020) has revealed resistances to leaf, stem and stripe rust not observed in the parental wheat lines and thus likely conferred by introgressed genes. KASP genotyping to identify segments has been conducted on many of these lines (Grewal et al, 2021).…”

“…muticum derived rust resistance Two of the lines that we sequenced, DH92 and DH121 (fig. 5A), have complete resistance at the seedling stage to Kansas isolates of Puccinia striiformis tritici (stripe/yellow rust) (Fellers et al, 2020). DH92 also displays chlorotic adult resistance to leaf rust and partial resistance to stem rust that is absent in DH121.…”