Department of Horticultural Science, North Carolina State University, Raleigh, NC 27695, USA.
Current address: Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Int J Mol Sci. 2020 Mar 3;21(5):1734. doi: 10.3390/ijms21051734.
Bacterial spot is a serious disease of tomato caused by at least four species of . These include (race T1), (race T2), (races T3 and T4), and with the distinct geographical distribution of each group. Currently, and are two major bacterial pathogens of tomato in North America, with (race T4) dominating in east-coast while dominating in the Midwest. The disease causes up to 66% yield loss. Management of this disease is challenging due to the lack of useful chemical control measures and commercial resistant cultivars. Although major genes for resistance () and quantitative resistance have been identified, breeding tomato for resistance to bacterial spot has been impeded by multiple factors including the emergence of new races of the pathogen that overcome the resistance, multigenic control of the resistance, linkage drag, non-additive components of the resistance and a low correlation between seedling assays and field resistance. Transgenic tomato with and genes was effective against multiple races of . However, it has not been commercialized because of public concerns and complex regulatory processes. The genomics-assisted breeding, effectors-based genomics breeding, and genome editing technology could be novel approaches to achieve durable resistance to bacterial spot in tomato. The main goal of this paper is to understand the current status of bacterial spot of tomato including its distribution and pathogen diversity, challenges in disease management, disease resistance sources, resistance genetics and breeding, and future prospectives with novel breeding approaches.
细菌性斑点病是一种严重的番茄病害，由至少四个物种引起。这些物种包括 （T1 型）、 （T2 型）、 （T3 和 T4 型）和 ，每个物种都有明显的地理分布。目前， 和 是北美番茄的两种主要细菌性病原菌，其中 （T4 型）在东海岸占主导地位，而 则在中西部占主导地位。该病害可导致高达 66%的产量损失。由于缺乏有效的化学防治措施和商业抗性品种，该病害的防治具有挑战性。虽然已经鉴定出主要的抗性基因（ ）和数量抗性基因，但由于多种因素的影响，如病原菌新的毒力型的出现、抗性的多基因控制、连锁累赘、抗性的非加性成分以及幼苗鉴定与田间抗性之间的低相关性，培育对细菌性斑点病具有抗性的番茄品种受到阻碍。具有 和 基因的转基因番茄对多种 的毒力型有效。然而，由于公众的担忧和复杂的监管程序，它尚未商业化。基于基因组的辅助育种、效应子基因组学育种和基因组编辑技术可能是实现番茄细菌性斑点病持久抗性的新方法。本文的主要目的是了解番茄细菌性斑点病的现状，包括其分布和病原菌多样性、病害管理的挑战、抗病性来源、抗性遗传学和育种以及利用新型育种方法的未来前景。
