Abstract Grain hardness and starch are two of the most important factors that determine the end-use quality of bread wheat (Triticum aestivum L.) grain. The grain hardness and amylose content are controlled by the puroindolines (Pina-D1 and Pinb-D1) genes, located on chromosomes 5D, and waxy (Wx-A1, -B1 and -D1) genes, located on chromosomes 7A, 4A and 7D. A total of 160 Iranian landraces from the Germplasm Bank of the International Maize and Wheat Improvement Center were evaluated for grain hardness using near infrared spectroscopy to predict the particle size index (PSI). In addition, molecular markers were used to evaluate the states of the corresponding genes. Eight accessions were found to have a hard texture (predicted PSI < 45%); however, only two could be explained by null alleles either in Pina-D1 or Pinb-D1. Additionally, 152 accessions had semi-hard textures (predicted PSI range of 45% to 55%). For the Wx gene, only one accession (CWI 67665) showed the null Wx-D1b allele, while two accessions (CWI 67747 and CWI 57684) were null for Wx-B1b. Single nucleotide polymorphism and sequence tag site marker techniques were used. Our findings further indicate the importance of using these landraces for grain quality improvement in breeding programs.

中文翻译：

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伊朗面包小麦 (Triticum aestivum L.) 地方品种中的嘌呤二氢吲哚 (Pina-D1 和 Pinb-D1) 和蜡质 (Wx-1) 基因

摘要 谷物硬度和淀粉是决定面包小麦（Triticum aestivum L.）谷物最终使用品质的两个最重要的因素。谷物硬度和直链淀粉含量由位于染色体 5D 上的嘌呤二氢吲哚（Pina-D1 和 Pinb-D1）基因和位于染色体 7A、4A 和 7D 上的蜡质（Wx-A1、-B1 和 -D1）基因控制. 使用近红外光谱法对来自国际玉米和小麦改良中心种质库的 160 种伊朗地方品种的谷物硬度进行了评估，以预测粒度指数 (PSI)。此外，分子标记用于评估相应基因的状态。发现 8 个材料质地坚硬（预测 PSI < 45%）；然而，只有两个可以用 Pina-D1 或 Pinb-D1 中的无效等位基因来解释。此外，152 个种质具有半硬质（预测 PSI 范围为 45% 至 55%）。对于 Wx 基因，只有一个样本 (CWI 67665) 显示无效的 Wx-D1b 等位基因，而两个样本（CWI 67747 和 CWI 57684）对于 Wx-B1b 是无效的。使用了单核苷酸多态性和序列标签位点标记技术。我们的研究结果进一步表明在育种计划中使用这些地方品种改善谷物质量的重要性。