Zinger Avner, Lapidot Moshe, Harel Arye, Doron-Faigenboim Adi, Gelbart Dana, Levin Ilan
The Institute of Plant Sciences, Agricultural Research Organization, Volcani Center, 68 HaMaccabim Road, P.O. Box 15159 Rishon LeZion 7505101, Israel.
The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12 Rehovot 7610001, Israel.
Plants (Basel). 2021 Jan 19;10(1):179. doi: 10.3390/plants10010179.
Tomato brown rugose fruit virus (ToBRFV) was identified in Israel during October 2014 in tomato plants (). These plants, carrying the durable resistance gene against tomato mosaic virus, , displayed severe disease symptoms and losses to fruit yield and quality. These plants were found infected with a tobamovirus similar to that discovered earlier in Jordan. This study was designed to screen and identify tomato genotypes resistant or tolerant to ToBRFV. The identified resistance and tolerance traits were further characterized virologically and genetically. Finally, DNA markers linked to genes controlling these traits were developed as tools to expedite resistance breeding. To achieve these objectives, 160 genotypes were screened, resulting in the identification of an unexpectedly high number of tolerant genotypes and a single genotype resistant to the virus. A selected tolerant genotype and the resistant genotype were further analyzed. Analysis of genetic inheritance revealed that a single recessive gene controls tolerance whereas at least two genes control resistance. Allelic test between the tolerant and the resistant genotype revealed that these two genotypes share a locus controlling tolerance, mapped to chromosome 11. This locus displayed a strong association with the tolerance trait, explaining nearly 91% of its variation in segregating populations. This same locus displayed a statistically significant association with symptom levels in segregating populations based on the resistant genotype. However, in these populations, the locus was able to explain only ~41% of the variation in symptom levels, confirming that additional loci are involved in the genetic control of the resistance trait in this genotype. A locus on chromosome 2, at the region of the gene, was finally found to interact with the locus discovered on chromosome 11 to control resistance.
番茄褐色皱果病毒（ToBRFV）于2014年10月在以色列的番茄植株中被发现（）。这些携带抗番茄花叶病毒持久抗性基因的植株表现出严重的病害症状，果实产量和品质受损。这些植株被发现感染了一种与早些时候在约旦发现的烟草花叶病毒类似的病毒。本研究旨在筛选和鉴定对ToBRFV具有抗性或耐受性的番茄基因型。对鉴定出的抗性和耐受性性状进行了病毒学和遗传学进一步表征。最后，开发了与控制这些性状的基因连锁的DNA标记，作为加速抗性育种的工具。为实现这些目标，对160个基因型进行了筛选，结果鉴定出数量意外之多的耐受性基因型和一个对该病毒具有抗性的基因型。对一个选定的耐受性基因型和抗性基因型进行了进一步分析。遗传遗传分析表明，一个隐性基因控制耐受性，而至少两个基因控制抗性。耐受性基因型和抗性基因型之间的等位基因测试表明，这两个基因型共享一个控制耐受性的位点，该位点定位于第11号染色体。该位点与耐受性性状表现出强烈关联，解释了分离群体中近91%的变异。基于抗性基因型，该相同位点在分离群体中与症状水平也表现出统计学上显著的关联。然而，在这些群体中，该位点仅能解释症状水平变异的约41%，证实该基因型中抗性性状的遗传控制还涉及其他位点。最终发现第2号染色体上位于基因区域的一个位点与在第11号染色体上发现的位点相互作用以控制抗性。
