Scotland's Rural College (SRUC), Kings Buildings, West Mains Road, Edinburgh, EH9 3JG, UK.
Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3BF, UK.
Theor Appl Genet. 2024 Apr 30;137(5):115. doi: 10.1007/s00122-024-04618-9.
This study found that the genes, PPD-H1 and ELF3, control the acceleration of plant development under speed breeding, with important implications for optimizing the delivery of climate-resilient crops. Speed breeding is a tool to accelerate breeding and research programmes. Despite its success and growing popularity with breeders, the genetic basis of plant development under speed breeding remains unknown. This study explored the developmental advancements of barley genotypes under different photoperiod regimes. A subset of the HEB-25 Nested Association Mapping population was evaluated for days to heading and maturity under two contrasting photoperiod conditions: (1) Speed breeding (SB) consisting of 22 h of light and 2 h of darkness, and (2) normal breeding (NB) consisting of 16 h of light and 8 h of darkness. GWAS revealed that developmental responses under both conditions were largely controlled by two loci: PPDH-1 and ELF3. Allelic variants at these genes determine whether plants display early flowering and maturity under both conditions. At key QTL regions, domesticated alleles were associated with late flowering and maturity in NB and early flowering and maturity in SB, whereas wild alleles were associated with early flowering under both conditions. We hypothesize that this is related to the dark-dependent repression of PPD-H1 by ELF3 which might be more prominent in NB conditions. Furthermore, by comparing development under two photoperiod regimes, we derived an estimate of plasticity for the two traits. Interestingly, plasticity in development was largely attributed to allelic variation at ELF3. Our results have important implications for our understanding and optimization of speed breeding protocols particularly for introgression breeding and the design of breeding programmes to support the delivery of climate-resilient crops.
本研究发现，PPD-H1 和 ELF3 基因控制着在加速培育下植物发育的加速，这对优化具有气候适应能力的作物的传递具有重要意义。加速培育是一种加速繁殖和研究计划的工具。尽管它在育种者中取得了成功并越来越受欢迎，但在加速培育下植物发育的遗传基础仍然未知。本研究探讨了不同光周期条件下大麦基因型的发育进展。对 HEB-25 嵌套关联图谱群体的一个子集进行了评估，以确定在两种不同光周期条件下的抽穗期和成熟期：（1）由 22 小时光照和 2 小时黑暗组成的加速培育（SB），（2）由 16 小时光照和 8 小时黑暗组成的正常培育（NB）。GWAS 显示，两种条件下的发育反应主要由两个基因座控制：PPDH-1 和 ELF3。这些基因的等位变异决定了植物在两种条件下是否表现出早花和成熟。在关键 QTL 区域，驯化等位基因与 NB 下的晚花和成熟以及 SB 下的早花和成熟有关，而野生等位基因与两种条件下的早花有关。我们假设这与 ELF3 对 PPD-H1 的黑暗依赖性抑制有关，这种抑制在 NB 条件下可能更为明显。此外，通过比较两种光周期条件下的发育，我们得出了这两个性状的可塑性估计值。有趣的是，发育的可塑性在很大程度上归因于 ELF3 的等位变异。我们的研究结果对我们理解和优化加速培育方案具有重要意义，特别是对导入育种和支持具有气候适应能力的作物传递的育种计划的设计。
