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Wheat (Triticum aestivum L.) wild relatives are rich genetic resources for genetic improvement of wheat. The short arm of rye (Secale cereale L.) chromosome 1 (1RS) contains many beneficial genes for resistance to drought, insects, and diseases, therefore the 1RS wheat translocations have been widely used in wheat breeding programs worldwide. To facilitate marker‐assisted identification of 1RS in wheat breeding, we designed a set of Kompetitive allele‐specific polymerase chain reaction (KASP) markers to detect the translocations of 1RS with long arm from wheat chromosome 1A (1RS.1AL) and 1RS with long arm from wheat chromosome 1B (1RS.1BL) based on the sequence flanking single nucleotide polymorphisms (SNPs) generated by genotyping‐by‐sequencing (GBS) between wheat and rye panels. We identified a set of three SNP markers for diagnosis and differentiation of the two 1RS translocations in wheat. Among the three KASP markers, 1AS‐05056 is 1RS specific, and clearly separated the genotypes with 1RS (1RS.1AL and 1RS.1BL) from those without the two 1RS translocations; whereas 1AS‐29875 clearly identified the 1RS.1AL translocation and 1BS‐16654 separated 1RS.1BL from 1RS.1AL. The three new KASP markers together accurately identified the presence of 1RS translocation on either 1A or 1B chromosome in a panel of 95 representative U.S. winter wheat accessions, which were further validated in two additional U.S. hard winter wheat panels. Therefore, they can be used for routine screening of 1RS.1BL and 1RS.1AL translocation lines in wheat breeding programs. Core Ideas: 1RS, 1AS, and 1BS specific SNPs were identified by analyzing GBS‐SNPs from both wheat and rye panels.Three chromosome‐arm‐specific KASPs clearly detected the 1RS.1AL and 1RS.1BL translocations in wheat.Three KASP markers were diagnostic for 1RS.1AL and 1RS.1BL in two U.S. hard winter wheat panels. [ABSTRACT FROM AUTHOR]

Hessian fly (HF, Mayetiola destructor Say), is a destructive insect pest in most wheat (Triticum aestivum L.) growing areas worldwide. Growing resistant cultivars can effectively reduce HF damage. The wheat cultivar 'Seneca' was reported to carry resistance genes H7 on chromosome 5D and H8 with unknown location. To further validate the resistance gene locations in Seneca, a recombinant inbred line (RIL) population from Bobwhite × Seneca was genotyped using 3,330 single nucleotide polymorphism (SNP) markers generated from genotyping‐by‐sequencing (GBS) and phenotyped for HF resistance in the greenhouse experiments. Phenotypic analyses showed at least two genes conditioning HF resistance in Seneca, but none of them was mapped on chromosome 5D, as previously reported. Instead, one major gene, designated as H7, was mapped to chromosome 6A and explained 60.7–78.3% of the phenotypic variation. The other gene with a minor effect, designated as H8, was found on chromosome 2B and explained 3.2–4.7% of the phenotypic variation. Based on the physical locations of flanking markers for H7 in the Chinese Spring reference genome, H7 was physically located in a 6‐Mb interval on 6AL. This study reassigned the major gene H7 to chromosome 6A and the minor gene H8 to 2B in Seneca using a high‐density SNP map. Seventeen GBS SNPs mapped in the H7 region were converted into Kompetitive allele specific polymerase chain reaction (KASP) markers for selecting this gene in breeding. [ABSTRACT FROM AUTHOR]

BACKGROUND Understanding the variance of antioxidant in wheat grain responses to irrigation and nitrogen (N) fertiliser management will improve the nutrient quality of wheat grain. Four N rates (0, 180, 240, and 300 kg ha−1) combined with irrigation times (I0, no irrigation; I1, jointing time irrigation; I2, jointing + flowering time irrigation), were used to determine the effect of N fertilisation and irrigation on total phenolic content (TPC), phenolic acid composition, and antioxidant activity (AOA) of wheat grain. RESULTS Irrigation, N fertilisation and their interactions had significant effect on TPC, total flavonoid content (TFC), AOA, p-coumaric acid (PCA), as well as vanillic acid (VA) and chlorogenic acid (CA). I1N300 treatment had the highest TPC at Zhengzhou and Wenxian (1451.5 µg g−1 and 1397.9 µg g−1, respectively) location, while I1N240 resulted in the highest TFC (0.75 mg g−1) and VA (19.77 µg g−1) at Wenxian. TPC, TFC, AOA, ferulic acid (FA), PCA and VA increased with N application rate (from 180 to 300 kg N ha−1). CONCLUSION An appropriate irrigation and N management improved antioxidant content and AOA in wheat grain. Generally, I1N240 and I1N300 treatment resulted in the higher TPC, TFC, AOA, as well as phenolic acid, i.e. FA and VA. © 2014 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: Flavonoids are the low molecular weight polyphenolic secondary metabolic compounds, and have various functions in growth, development, reproduction, and stress defense. However, little is known about the roles of the key enzymes in the flavonoids biosynthesis pathway in response to drought stress in winter wheat. Here, we investigated the expression pattern of flavonoids biosynthesis genes and accumulation of flavonoids in wheat leaves under drought stress. Quantitative real-time PCR analysis showed that there were a rapid increase in expression levels of TaCHS, TaCHI, TaF3H, TaFNS, TaFLS, TaDFR, and TaANS under drought stress in two wheat cultivars Aikang 58 (AK) and Chinese Spring (CS). The cultivar CS exhibited higher genes expression levels of TaCHS, TaCHI, TaF3H, TaFLS, TaDFR, and TaANS, and the cultivar AK showed a higher expression level of TaFNS gene during drought treatment. The increase rates of genes expression were superior in AK compared to CS. Total phenolics content, total flavonoids content, anthocyanin content, and schaftoside content in wheat leaves were enhanced during drought treatment and cultivar CS had a relative higher accumulation. These results suggest that the flavonoids pathway genes expression and accumulation of flavonoids compounds may be closely related to drought tolerant in wheat. Further, flavonoids response mechanism may be different between wheat cultivars. [Copyright &y& Elsevier]