Late blight (LB), caused by Phytophthora infestans, is one of the most devastating diseases of tomato (Solanum lycopersicum) worldwide. Aggressive pathogen isolates resistant to fungicides have driven research in favour of finding new sources of host resistance for tomato breeding. Recently, we reported S. pimpinellifolium accession PI 270443 exhibiting LB resistance stronger than all commercial LB‐resistant tomato cultivars. The purpose of this study was to examine the inheritance of LB resistance conferred by this accession. An interspecific cross was made between PI 270443 and a LB‐susceptible tomato breeding line and advanced to F₁₀ generation. A total of 166 F₉ and corresponding F₁₀ recombinant inbred lines (RILs) were evaluated for response to LB in four replicated greenhouse experiments. Estimates of heritability (h²) of LB resistance, determined by parent–offspring (F₉:F₁₀) correlation analysis, ranged from 0.66 to 0.81, with an average of 0.76. The moderately high h² of LB resistance in PI 270443 suggests the utility of this accession for tomato breeding. Molecular mapping and RNA‐sequencing efforts are underway to identify genes underlying LB resistance in PI 270443.

中文翻译：

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源自耐LB的茄属植物Pimpinellifolium加入PI 270443的新RIL番茄群体的晚疫病抗性遗传分析

由疫霉疫霉引起的晚疫病（LB）是全球最具破坏力的番茄疾病（Solanum lycopersicum）之一。对杀真菌剂具有抗性的侵略性病原体分离物推动了研究的发展，有利于为番茄育种寻找宿主抗性的新来源。近来，我们报道了品脱链球菌（S. pimpinellifolium）登录号PI 270443表现出比所有商业耐LB番茄品种更强的LB抗性。这项研究的目的是检查这种登录所赋予的LB抗性的遗传。PI 270443和LB易感番茄育种品系之间进行了种间杂交，并杂交至F ₁₀代。总共166个F ₉和对应的F ₁₀在四个重复的温室实验中评估了重组自交系（RIL）对LB的反应。通过亲子（F ₉：F ₁₀）相关分析确定的LB抗性的遗传力（h ²）估计值在0.66至0.81之间，平均为0.76。适度高ħ ²在PI 270443 LB电阻表明，这种加入的番茄育种的实用程序。目前正在进行分子定位和RNA测序工作，以鉴定PI 270443中LB抗性的基础基因。