Abebe Alebel Mekuriaw, Oh Chang-Sik, Kim Hyoung Tae, Choi Giwon, Seo Eunyoung, Yeam Inhwa, Lee Je Min
Department of Horticultural Science, Kyungpook National University, Daegu, South Korea.
Department of Horticultural Biotechnology, College of Life Science, Kyung Hee University, Yongin, South Korea.
Front Plant Sci. 2022 Jan 26;12:809959. doi: 10.3389/fpls.2021.809959. eCollection 2021.
Bacterial canker caused by () is one of the most economically important vascular diseases causing unilateral leaf wilting, stem canker, a bird's-eye lesion on fruit, and whole plant wilting in tomato. There is no commercially available cultivar with bacterial canker resistance, and genomics-assisted breeding can accelerate the development of cultivars with enhanced resistance. "Hawaii 7998" was found to show bacterial canker resistance. A Quantitative trait loci (QTL)-seq was performed to identify the resistance loci using 909 F individuals derived from a cross between "E6203" (susceptible) and "Hawaii 7998," and a genomic region (37.24-41.15 Mb) associated with bacterial canker resistance on chromosome 6 () was found. To dissect the region, 12 markers were developed and several markers were associated with the resistance phenotypes. Among the markers, the Rcm6-9 genotype completely matched with the phenotype in the 47 cultivars. To further validate the as a resistance locus and the Rcm6-9 efficiency, subsequent analysis using F and F progenies was conducted. The progeny individuals with homozygous resistance allele at the Rcm6-9 showed significantly lower disease severity than those possessing homozygous susceptibility alleles. Genomes of five susceptible and two resistant cultivars were analyzed and previously known R-genes were selected to find candidate genes for . Nucleotide-binding leucine-rich repeat, receptor-like kinase, and receptor-like protein were identified to have putative functional mutations and show differential expression upon the infection. The DNA markers and candidate genes will facilitate marker-assisted breeding and provide genetic insight of bacterial canker resistance in tomato.
由（）引起的番茄细菌性溃疡病是最具经济重要性的维管束病害之一，可导致番茄叶片单侧萎蔫、茎溃疡、果实上出现鸟眼状病斑以及整株萎蔫。目前尚无具有抗细菌性溃疡病的商业栽培品种，而基因组辅助育种可加速培育抗性增强的品种。已发现“夏威夷7998”表现出抗细菌性溃疡病。利用来自“E6203”（感病）与“夏威夷7998”杂交的909个F个体进行了数量性状位点（QTL）测序，以鉴定抗性位点，并在6号染色体（）上发现了一个与细菌性溃疡病抗性相关的基因组区域（37.24 - 41.15 Mb）。为剖析该区域，开发了12个标记，其中几个标记与抗性表型相关。在这些标记中，Rcm6 - 9基因型在47个品种中与表型完全匹配。为进一步验证该区域作为抗性位点以及Rcm6 - 9的有效性，利用F和F后代进行了后续分析。在Rcm6 - 9处具有纯合抗性等位基因的后代个体的病害严重程度显著低于具有纯合感病等位基因的个体。分析了5个感病品种和2个抗病品种的基因组，并选择了先前已知的R基因来寻找该区域的候选基因。已鉴定出核苷酸结合富亮氨酸重复序列、类受体激酶和类受体蛋白具有推定的功能突变，并在感染后表现出差异表达。这些DNA标记和候选基因将有助于标记辅助育种，并为番茄细菌性溃疡病抗性提供遗传见解。
