Scholarlink

Key message <p>This study reveals a pleiotropic QTL <i>QPh/Sl/Sn.cau-2D.1</i> coordinating plant architecture and spike morphology in wheat, and identifies <i>REGULATOR OF GRAIN NUMBER1 (TaRGN-D1)</i> as a key regulator of spikelet number, providing molecular targets and diagnostic markers for yield improvement.</p> Abstract <p>Spike architecture traits, particularly spike length (SL) and spikelet number per spike (SN), are crucial determinants of grain yield in wheat (<i>Triticum aestivum</i> L.), while plant height (PH) independently affects lodging resistance, harvest index and final yield potential. Through comprehensive genetic analysis of a recombinant inbred line population derived from AS420 (large-spike line) × Lunxuan987 (LX987, modern cultivar), we identified 36 spike-specific QTLs (22 for SL and 14 for SN) with 22 showing environments stability,&#xa0;and 12 additional PH QTLs with 13 showing environmental stability, using 55&#xa0;K SNP genotyping across six environments. A pleiotropic locus (<i>QPh/Sl/Sn.cau-2D.1</i>) on chromosome 2DS co-regulated PH, SL and SN (8.4–19.75% phenotypic variance (PVE)), and a 2,089-bp deletion on <i>Ppd-D1</i> promoter was identified as the causal variant. In addition, we characterized <i>REGULATOR OF GRAIN NUMBER1</i> (<i>TaRGN-D1</i>, TraesCS3D02G265100), encoding R2R3-MYB transcription factor, as the candidate gene for a major SN QTL <i>QSn.cau-3D</i> (6.5% PVE). Functional studies revealed a stronger transcriptional activation by the AS420-derived <i>TaRGN-D1</i> promoter compared to LX987, correlating with elevated expression during spike development. Field validation confirmed the positive effect of <i>TaRGN-D1</i> on SN without altering PH. Our findings not only identify new QTLs for wheat molecular breeding of high-yielding purpose, but also deepen our genetic comprehension on PH, SL, and SN regulation in this crop, thereby laying a valuable foundation for future wheat improvement strategies.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Molecular dissection of large-spike trait in wheat revealing stable QTLs and REGULATOR OF GRAIN NUMBER1 as targets for yield improvement

  • 期刊论文

  • 发表日期：

    2025年10月22日

查看全文
  • Yujie Jiang,
  • Haoran Wang,
  • Yanming Ma,
  • Junxian Liu,
  • Zhaoyan Chen,
  • Chaoqun Dong,
  • Xiangqing Liu,
  • Xincheng Wang,
  • Yiqing Wang,
  • Sufang Li,
  • Yingyin Yao,
  • Mingming Xin,
  • Zhongfu Ni,
  • Huiru Peng,
  • Qixin Sun,
  • Xingguo Ye,
  • Jie Liu

摘要

Key message

This study reveals a pleiotropic QTL QPh/Sl/Sn.cau-2D.1 coordinating plant architecture and spike morphology in wheat, and identifies REGULATOR OF GRAIN NUMBER1 (TaRGN-D1) as a key regulator of spikelet number, providing molecular targets and diagnostic markers for yield improvement.

Abstract

Spike architecture traits, particularly spike length (SL) and spikelet number per spike (SN), are crucial determinants of grain yield in wheat (Triticum aestivum L.), while plant height (PH) independently affects lodging resistance, harvest index and final yield potential. Through comprehensive genetic analysis of a recombinant inbred line population derived from AS420 (large-spike line) × Lunxuan987 (LX987, modern cultivar), we identified 36 spike-specific QTLs (22 for SL and 14 for SN) with 22 showing environments stability, and 12 additional PH QTLs with 13 showing environmental stability, using 55 K SNP genotyping across six environments. A pleiotropic locus (QPh/Sl/Sn.cau-2D.1) on chromosome 2DS co-regulated PH, SL and SN (8.4–19.75% phenotypic variance (PVE)), and a 2,089-bp deletion on Ppd-D1 promoter was identified as the causal variant. In addition, we characterized REGULATOR OF GRAIN NUMBER1 (TaRGN-D1, TraesCS3D02G265100), encoding R2R3-MYB transcription factor, as the candidate gene for a major SN QTL QSn.cau-3D (6.5% PVE). Functional studies revealed a stronger transcriptional activation by the AS420-derived TaRGN-D1 promoter compared to LX987, correlating with elevated expression during spike development. Field validation confirmed the positive effect of TaRGN-D1 on SN without altering PH. Our findings not only identify new QTLs for wheat molecular breeding of high-yielding purpose, but also deepen our genetic comprehension on PH, SL, and SN regulation in this crop, thereby laying a valuable foundation for future wheat improvement strategies.