Zhang Dongye, Li Huijia, Liu Guan, Xie Libo, Feng Guojun, Xu Xiangyang
College of Advanced Agriculture and Ecological Environment, Heilongjiang University, Harbin, China.
Laboratory of Genetic Breeding in Tomato, College of Horticulture and Landscape Architecture, Northeast Agricultural University, Harbin, China.
Front Genet. 2023 Jul 27;14:1219898. doi: 10.3389/fgene.2023.1219898. eCollection 2023.
Tomato () is widely cultivated and consumed worldwide. Tomato leaf mold, caused by , is one of the most devastating diseases in tomato production. At present, some tomato leaf mold resistance ( series) genes used in production gradually lose resistance due to the continuous and rapid differentiation of physiological races. The gene derived from the "Ontario7816" tomato cultivar has shown effective resistance in field trials for many years, but few studies have reported on the mapping of the gene, which has not been cloned, limiting its utilization in tomato breeding. Here, we mapped using a novel comprehensive strategy including bulk segregation analysis (BSA), genome resequencing and SSR molecular markers. A genetic analysis revealed that resistance in "Ontario7816" is controlled by one major dominant locus. The gene was mapped in a region of 2.6 cM at chromosome 6 between two markers, namely, TGS447 and TES312, by using an F population from a cross between the resistant cultivar "Ontario7816" and susceptible line "Moneymaker." Two nucleotide-binding-site-leucine-rich repeat (NBS-LRR) resistance genes, namely, XM_004240667.3 and XM_010323727.1, were identified in this interval. They are strong candidates for the gene. The mapping of may speed up its utilization for breeding resistant tomato varieties and represents an important step forward in our understanding of the mechanism underlying resistance to tomato leaf mold.
番茄（）在全球广泛种植和食用。由引起的番茄叶霉病是番茄生产中最具毁灭性的病害之一。目前，生产中使用的一些番茄叶霉病抗性（系列）基因由于生理小种的持续快速分化而逐渐丧失抗性。源自“安大略7816”番茄品种的基因在多年的田间试验中表现出有效的抗性，但关于该基因的定位研究报道较少，且尚未克隆，限制了其在番茄育种中的应用。在此，我们采用了包括混合分离分析法（BSA）、基因组重测序和SSR分子标记在内的新型综合策略对进行定位。遗传分析表明，“安大略7816”中的抗性由一个主要显性位点控制。通过使用抗性品种“安大略7816”和感病品系“Money maker”杂交产生的F群体，将基因定位在6号染色体上两个标记TGS447和TES312之间2.6 cM的区域内。在该区间鉴定出两个核苷酸结合位点富含亮氨酸重复序列（NBS-LRR）抗性基因，即XM_004240667.3和XM_010323727.1。它们是基因的有力候选者。基因的定位可能会加速其在抗番茄叶霉病品种育种中的应用，并代表着我们在理解番茄叶霉病抗性潜在机制方面向前迈出的重要一步。
