Faculty of Science, University of Melbourne, Parkville, Melbourne, Victoria, Australia.
AgriBio, Centre for AgriBioscience, Agriculture Victoria Research, Bundoora, Victoria, Australia.
Plant J. 2024 Jan;117(1):23-32. doi: 10.1111/tpj.16488. Epub 2023 Nov 16.
Heterosis, also known as hybrid vigor, is the phenomenon wherein a progeny exhibits superior traits relative to one or both parents. In terms of crop breeding, this usually refers to the yield advantage of F hybrids over both inbred parents. The development of high-yielding hybrid cultivars across a wider range of crops is key to meeting future food demands. However, conventional hybrid breeding strategies are proving to be exceptionally challenging to apply commercially in many self-pollinating crops, particularly wheat and barley. Currently in these crops, the relative performance advantage of hybrids over inbred line cultivars does not outweigh the cost of hybrid seed production. Here, we review the genetic basis of heterosis, discuss the challenges in hybrid breeding, and propose a strategy to recruit multiple heterosis-associated genes to develop lines with improved agronomic characteristics. This strategy leverages modern genetic engineering tools to synthesize supergenes by fusing multiple heterotic alleles across multiple heterosis-associated loci. We outline a plan to assess the feasibility of this approach to improve line performance using barley (Hordeum vulgare) as the model self-pollinating crop species, and a few heterosis-associated genes. The proposed method can be applied to all crops for which heterotic gene combinations can be identified.
杂种优势，又称杂种优势，是指后代相对于一个或两个亲本表现出优越性状的现象。在作物育种方面，这通常是指 F1 杂种相对于两个自交系亲本的产量优势。开发更广泛的作物的高产杂交品种是满足未来粮食需求的关键。然而，传统的杂交育种策略在许多自交作物中，特别是在小麦和大麦中，证明在商业上具有挑战性。目前，在这些作物中，杂种相对于自交系品种的相对表现优势并不超过杂交种子生产的成本。在这里，我们回顾了杂种优势的遗传基础，讨论了杂交育种的挑战，并提出了一种策略，即招募多个与杂种优势相关的基因，以开发具有改良农艺特性的品系。该策略利用现代遗传工程工具，通过融合多个杂种优势相关基因座中的多个杂种优势等位基因来合成超级基因。我们概述了一项使用大麦（Hordeum vulgare）作为自交作物模型物种和一些与杂种优势相关的基因来评估该方法提高品系性能的可行性的计划。所提出的方法可以应用于所有可以确定杂种优势基因组合的作物。
