Wheatgrass Thinopyrum Intermedium Research Articles

Raise and characterization of a bread wheat hybrid line (Tulaykovskaya 10 × Saratovskaya 29) with chromosome 6Agi2 introgressed from Thinopyrum intermedium.

Wheatgrass Thinopyrum intermedium is a source of agronomically valuable traits for common wheat. Partial wheat–wheatgrass amphidiploids and lines with wheatgrass chromosome substitutions are extensively used as intermediates in breeding programs. Line Agis 1 (6Agi2/6D) is present in the cultivar Tulaykovskaya 10 pedigree. Wheatgrass chromosome 6Agi2 carries multiple resistance to fungal diseases in various ecogeographical zones. In this work, we studied the transfer of chromosome 6Agi2 in hybrid populations Saratovskaya 29 × skaya 10 (S29 × T10) and Tulaykovskaya 10 × Saratovskaya 29 (T10 × S29). Chromosome 6Agi2 was identif ied by PCR with chromosome-specif ic primers and by genomic in situ hybridization (GISH). According to molecular data, 6Agi2 was transmitted to nearly half of the plants tested in the F2 and F3 generations. A new breeding line 49-14 (2n = 42) with chromosome pair 6Agi2 was isolated and characterized in T10 × S29 F5 by GISH. According to the results of our f ield experiment in 2020, the line had high productivity traits. The grain weights per plant (10.04 ± 0.93 g) and the number of grains per plant (259.36 ± 22.49) did not differ signif icantly from the parent varieties. The number of grains per spikelet in the main spike was signif icantly higher than in S29 ( p ≤ 0.001) or T10 ( p ≤ 0.05). Plants were characterized by the ability to set 3.77 ± 0.1 grains per spikelet, and this trait varied among individuals from 2.93 to 4.62. The grain protein content was 17.91 %, and the gluten content, 40.55 %. According to the screening for fungal disease resistance carried out in the f ield in 2018 and 2020, chromosome 6Agi2 makes plants retain immunity to the West Siberian population of brown rust and to dominant races of stem rust. It also provides medium resistant and medium susceptible types of response to yellow rust. The possibility of using lines/varieties of bread wheat with wheatgrass chromosomes 6Agi2 in breeding in order to increase protein content in the grain, to confer resistance to leaf diseases on plants and to create multif lowered forms is discussed.

Abiotic and biotic context dependency of perennial crop yield.

Perennial crops in agricultural systems can increase sustainability and the magnitude of ecosystem services, but yield may depend upon biotic context, including soil mutualists, pathogens and cropping diversity. These biotic factors themselves may interact with abiotic factors such as drought. We tested whether perennial crop yield depended on soil microbes, water availability and crop diversity by testing monocultures and mixtures of three perennial crop species: a novel perennial grain (intermediate wheatgrass—Thinopyrum intermedium-- that produces the perennial grain Kernza®), a potential perennial oilseed crop (Silphium intregrifolium), and alfalfa (Medicago sativa). Perennial crop performance depended upon both water regime and the presence of living soil, most likely the arbuscular mycorrhizal (AM) fungi in the whole soil inoculum from a long term perennial monoculture and from an undisturbed native remnant prairie. Specifically, both Silphium and alfalfa strongly benefited from AM fungi. The presence of native prairie AM fungi had a greater benefit to Silphium in dry pots and alfalfa in wet pots than AM fungi present in the perennial monoculture soil. Kernza did not benefit from AM fungi. Crop mixtures that included Kernza overyielded, but overyielding depended upon inoculation. Specifically, mixtures with Kernza overyielded most strongly in sterile soil as Kernza compensated for poor growth of Silphium and alfalfa. This study identifies the importance of soil biota and the context dependence of benefits of native microbes and the overyielding of mixtures in perennial crops.

Genome-Wide Association Study of Powdery Mildew Resistance in Russian Spring Wheat (T. aestivum L.) Varieties

Powdery mildew caused by the fungal pathogen Blumeria graminis f. sp. tritici (Bgt) is an econo-mically important disease of common wheat T. aestivum L. One of the most effective and environmentally important ways of protection of wheat against Bgt is cultivation of the varieties with genetic resistance. The aim of this work was to study the genetic diversity of Russian spring wheat varieties for the powdery mildew resistance loci. Phytopathological evaluation of 97 wheat varieties showed that no more than 10% of the varieties have low level of susceptibility to the Bgt population specific to the Western Siberian region. Association mapping carried out on the basis of SNP genotyping and phytopathological testing during three environmental seasons identified eight loci in chromosomes 1AL, 1DS, 2BL, 5AS, 5DS, 6AL, 6DL, and 7AL. A high impact to the phenotypic manifestation of the trait was established for genetic factors localized in chromosomes 5AS, 6AL, and 6DL. The long arm of chromosome 6D contains the gene Pm6Ai=2, which was introduced from wheatgrass Thinopyrum intermedium and provides effective protection against the powdery mildew pathogen. On the basis of comparative analysis of the chromosomal localization of the known Pm resistance genes and loci mapped in this work, it was assumed that QTLs in chromosomes 1DS, 5AS, and 6AL are novel, not previously described resistance loci. The obtained results can be used in breeding programs for selection of target loci and for development of molecular markers specific to Bgt resistance loci.

A Thinopyrum intermedium chromosome in bread wheat cultivars as a source of genes conferring resistance to fungal diseases

Wheatgrass Thinopyrum intermedium (Host), or Agropyron intermedium (Host) (2n = 42; genome formula, EEEstEstStSt) is one of the most valuable sources of highly effective resistance genes in wheat breeding. Bread wheat cultivars Tulaikovskaya 5, Tulaikovskaya 10, and Tulaikovskaya 100 derived from wheat—Thinopyrum crosses are highly resistant to leaf rust and powdery mildew, and moderately resistant to stem and yellow rust. C-banding, in situ hybridization, and assays with PLUG and SSR markers have demonstrated that wheat chromosome 6D in all three cultivars is substituted by the Th. intermedium homoeologous chromosome, 6Ai. This chromosome was designated 6Ai#2, because it differs from the earlier described homoeologous chromosome 6Ai#1. In situ hybridization with Pseudoroegneria spicata and Dasypyrum villosum genomic DNAs has allowed chromosome 6Ai#2 to be assigned to the E (=J) subgenome. Chromosome 6Ai#2 remained intact over long-term breeding efforts. Tests of leaf rust resistance of in F2 and F3 populations from a cross of a leaf rust–susceptible cultivar with Tulaikovskaya 10 has demonstrated that chromosome 6Ai#2 carries at least one gene locus for leaf rust resistance. This locus was designated Lr6Ai#2. It must be different from the known gene locus Lr38, located on the long arm of chromosome 7Ai#2 and now present in many translocation variants in bread wheat. The effect of a chromosome from the Th. intermedium subgenome E on resistance to powdery mildew, stem and yellow rust in Tulaikovskaya 5, Tulaikovskaya 10, and Tulaikovskaya 100 is discussed.