Poudel Mousami, McDuffee Sophia, Minsavage Gerald V, Hutton Samuel F, Sharma Anuj, Jones Jeffrey B
Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA.
Department of Horticultural Sciences, Gulf Coast Research and Education Center, Wimauma, FL 33598, USA.
Plants (Basel). 2025 Aug 17;14(16):2559. doi: 10.3390/plants14162559.
Bacterial spot of the pepper (BSP) and the tomato (BST) caused by multiple spp. remains a major constraint to production of both crops worldwide. The widespread breakdown of dominant resistance genes, such as , due to the emergence of virulent races, like P6, has underscored the need for more durable, non-race-specific resistance. The recessive genes, ; ; and , have emerged as promising alternatives, conferring broad-spectrum resistance without triggering a hypersensitive response. In this study, we systematically evaluated the individual and combinatorial effects of these three recessive resistance genes against three species, (), pv. (), and (). Using near-isogenic lines (NILs) developed in the susceptible Early Calwonder (ECW) background, we assessed the in planta bacterial population growth and symptom development across a panel of eight genotypes carrying different gene combinations. Our results demonstrate that , particularly when combined with either or , significantly reduces bacterial growth and disease severity across all three species. The triple-stacked line (ECW568 (i.e., , , and )) consistently displayed the strongest suppression of pathogen proliferation and symptom development. By contrast, and , alone or in combination, were largely ineffective. In some cases, combining with was less effective than alone. These findings reinforce the central role of in conferring quantitative resistance and highlight the additive benefit of pyramiding recessive resistance genes. Furthermore, we have demonstrated that these recessive resistance genes are effective in limiting the ability of the emerging pathogen, , to grow , and thus are predicted to offer a high level of resistance in the field. Our work provides key insights for breeding durable, broad-spectrum resistance into commercial pepper cultivars and offers a framework for integrated disease management strategies in the face of rapidly evolving bacterial pathogens.
由多种病原菌引起的辣椒细菌性斑点病（BSP）和番茄细菌性斑点病（BST）仍然是全球这两种作物生产的主要限制因素。由于毒性小种（如P6）的出现，导致诸如 等显性抗性基因广泛失效，这凸显了对更持久、非小种特异性抗性的需求。隐性基因；；和 已成为有前景的替代方案，可赋予广谱抗性而不引发超敏反应。在本研究中，我们系统地评估了这三个隐性抗性基因对三种病原菌（ （）、 pv. （）和 （））的单独和组合效应。利用在感病的早加州奇迹（ECW）背景下培育的近等基因系（NIL），我们评估了携带不同基因组合的一组八个基因型在植株内的细菌种群生长和症状发展情况。我们的结果表明， ，特别是与 或 组合时，能显著降低所有三种病原菌的细菌生长和病害严重程度。三基因叠加系（ECW568（即 、 和 ））始终表现出对病原体增殖和症状发展的最强抑制作用。相比之下， 和 单独或组合使用时大多无效。在某些情况下， 将 与 组合的效果不如单独使用 。这些发现强化了 在赋予定量抗性中的核心作用，并突出了隐性抗性基因叠加的累加效益。此外，我们已经证明这些隐性抗性基因在限制新出现的病原菌 的生长能力方面是有效的，因此预计在田间能提供高水平的抗性。我们的工作为将持久、广谱抗性培育到商业辣椒品种中提供了关键见解，并为面对快速进化的细菌病原体的综合病害管理策略提供了框架。
