As an important component of wheat (Triticum aestivum L.) yield, 1000-kernel weight (TKW) has played a crucial role in yield improvement in recent decades. Marker-assisted selection is an effective tool for improving quantitative traits; however, most markers have not been effectively applied in TKW improvement despite the identification of many loci associated with TKW. In this study, association mapping was performed using local cultivated varieties, and a previous linkage analysis was integrated to identify 10 candidate intervals. The corresponding kompetitive allele-specific PCR markers associated with TKW were successfully developed and screened in 1153 F₄ breeding lines. Three markers, namely, Ktkw-5B2, Ktkw-5D, and Ktkw-7D, were proved to be significantly related to TKW according to large-scale association mapping, and their ability to increase TKW was enhanced in combination. We applied the three markers in 150 F₆ breeding lines and obtained 25 high-TKW lines, indicating the availability in marker-assisted selection. The TKW-increasing allele for Ktkw-5D was heavily selected in the present breeding program, while that for Ktkw-5B2 was low and for Ktkw-7D tended to increase after 2000. Furthermore, strategies for gene exploration in the three significant intervals were proposed. These results are expected to provide an efficient route for improving TKW in wheat high-yield breeding.

中文翻译：

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大规模育种群体验证小麦千粒重的重要位点


作为小麦（Triticum aestivum L.）产量的重要组成部分，千粒重（TKW）近几十年来在产量提高中发挥着至关重要的作用。标记辅助选择是改善数量性状的有效工具；然而，尽管鉴定了许多与 TKW 相关的基因座，但大多数标记尚未有效应用于 TKW 改进。在本研究中，使用当地栽培品种进行关联作图，并整合先前的连锁分析以确定 10 个候选区间。成功开发了与TKW相关的相应竞争性等位基因特异性PCR标记，并在1153个F ₄ 育种系中进行了筛选。根据大规模关联作图，Ktkw-5B2、Ktkw-5D和Ktkw-7D这三个标记被证明与TKW显着相关，并且它们组合后增加TKW的能力得到增强。我们将这三个标记应用于150个F ₆ 育种系中，获得了25个高TKW系，表明标记辅助选择的可用性。目前的育种计划中，Ktkw-5D的TKW增加等位基因被大量选择，而Ktkw-5B2的TKW增加等位基因较低，Ktkw-7D在2000年后有增加的趋势。此外，提出了在三个显着区间进行基因探索的策略。这些结果有望为小麦高产育种中TKW的提高提供有效途径。