Wheat grain texture is a complex trait. The crucial role of puroindoline genes in grain texture determination was confirmed. New loci, highly associated with the trait, were identified and dissected.

Grain texture is an important milling characteristic of common wheat. Previously, it was shown that the Ha locus on 5DS, containing the puroindoline-a, puroindoline-b and GSP-1 genes, has a crucial role in endosperm texture. However, some other loci were detected on different chromosomes, but no specific genes were proposed to be involved in grain hardness organization. In this study, we used a panel of Russian spring wheat varieties. The grain texture of varieties ranged from soft to hard. Analysis of the flour particle size and flour particle specific surface of wheat varieties cultivated in different environments demonstrated high heritability (0.79–0.8) and strong repeatability of the traits. Genotyping of wheat varieties with allele-specific markers for the puroindoline-a and puroindoline-b genes demonstrated that 25% of the studied varieties carried rare allele Pin-D1k, which lacked both Pina and Pinb (double null allele). Our results confirmed the strong impact of this allele on grain texture. Association analysis with the use of SNP genotyping (Illumina 15 K Wheat) and 2-year phenotyping confirmed the key role played by puroindoline genes (5D) in determining the grain texture of Russian wheat varieties. The analysis also detected significant SNPs on the 1B, 3A, 5B, 6A, 6D, 7B, 7D chromosomes. The best candidate loci for the grain texture were located on chromosomes 5B and 7B (FDR ≤ 0.05). We dissected a number of candidate genes and proposed a possible mechanism for their contribution to endosperm texture determination. These genes are involved in the metabolism of galactolipids (DGDG) and carbohydrates (1,3-β-glucan).

小麦籽粒的质地是一个复杂的特征。确认了嘌呤吲哚基因在谷物质地测定中的关键作用。与该性状高度相关的新基因座已被鉴定和解剖。

谷物质地是普通小麦的重要制粉特性。以前，已证明5DS上的Ha位点包含puroindoline -a，puroindoline-b和GSP-1基因，在胚乳质地中具有至关重要的作用。但是，在不同的染色体上检测到其他一些基因座，但没有提出特定基因参与晶粒硬度组织。在这项研究中，我们使用了一组俄罗斯春小麦品种。品种的质地从软到硬不等。对在不同环境下种植的小麦品种的面粉粒径和面粉比表面积的分析表明，遗传力高（0.79–0.8），且性状具有很强的重复性。与用于等位基因特异性标记物的小麦品种进行基因分型puroindoline-A和puroindoline-B基因表明，所研究的品种的25％进行罕见等位基因引脚D1K，其缺乏既翩和Pinb（双无效等位基因）。我们的结果证实了该等位基因对谷物质地的强烈影响。使用SNP基因分型（Illumina 15 K小麦）和2年表型进行的关联分析证实了嘌呤二氢吲哚基因（5D）在确定俄罗斯小麦品种的籽粒质地中起着关键作用。该分析还检测到1B，3A，5B，6A，6D，7B，7D染色体上的重要SNP。晶粒纹理的最佳候选基因座位于5B和7B染色体上（FDR≤0.05）。我们解剖了许多候选基因，并提出了它们对胚乳质地测定的可能机制。这些基因参与半乳糖脂（DGDG）和碳水化合物（1,3- β-葡聚糖）的代谢。