Evaluation of responses to tomato brown rugose fruit virus (ToBRFV) and selection of resistant lines in Solanum habrochaites and Solanum peruvianum germplasm

Abstract

Reactions of plants in 173 wild tomato accessions belonging to Solanum habrochaites and S. peruvianum were studied by inoculation with a tobamovirus, tomato brown rugose fruit virus (ToBRFV). Around 10–50% of plants in nine accessions of S. habrochaites and one of S. peruvianum were demonstrated to be highly resistant. Resistant plants showed no symptoms at 22–24 °C, and no virus could be detected in their inoculated and newly developed leaves using bioassays and RT-qPCR. ToBRFV-resistant plants were also resistant to tobacco mosaic virus and tomato mosaic virus. The susceptible wild tomatoes were infected systemically with ToBRFV showing different severity of symptoms. When resistant plants inoculated with ToBRFV were incubated in a plant growth chamber at a temperature of 33 °C, they expressed mosaic and deformation symptoms, indicating that the resistance was broken at elevated temperature. However, when these plants were transferred to the greenhouse at 24 °C, their newly emerged leaves showed no symptoms, and the virus could not be detected in the new leaves. Cleft grafting was done with scions from a resistant plant of S. habrochaites LA1739 into ToBRFV-infected susceptible tomato rootstock. The scions became infected and showed mosaic symptoms indicating that the resistance was ineffective after grafting. Sequences comparison of Solyc08g075630 loci of nine resistant accessions showed high heterogenity. Only one resistant plant of S. habrochaites carried an allele almost identical to the resistance gene reported previously. All other resistant plants may have probably unknown gene(s) of resistance to ToBRFV.

Understanding tobamovirus-plant interactions: implications for breeding resistance to tomato brown rugose fruit virus

“…In another recent study, Jewehan et al ( 2022b ) reported the evaluation of wild tomato accessions ( S. habrochaites and S. peruvianum ) infected by ToBRFV. From 173 samples, nine accessions of S. habrochaites and one of S. peruvianum were highly resistant.…”

Evaluation of Tomato Germplasm against Tomato Brown Rugose Fruit Virus and Identification of Resistance in Solanum pimpinellifolium

“…In the present study, it is defined as an inoculated plant showing no symptoms and testing negative for the virus [ 41 ]. Several efforts have been made in the search for new sources of genetic resistance to ToBRFV [ 42 , 43 , 44 , 45 ]. There is certainly remarkable complexity in the genetic resistance to ToBRFV, with more Solanum species in tolerance and few in resistance.…”

“…These tolerant lines include S. chilense [ 43 , 45 ], S. lycopersicum [ 42 ], S. lycopersicum var. cerasiforme [ 43 ], S. ochranthum [ 43 , 44 ], S. penellii [ 45 ], S. peruvianum [ 43 , 44 ], S. pimpinellifolium [ 42 , 43 , 45 ], and S. habrochaites [ 43 , 44 ]. There is little public information available on genetic inheritance, quantitative trait loci (QTLs) analyses and molecular marker development [ 42 ].…”

One-Step Reverse-Transcription Recombinase-Aided Amplification CRISPR/Cas12a-Based Lateral Flow Assay for Fast Field Screening and Accurate Differentiation of Four Major Tobamoviruses Infecting Tomato and Pepper

“…Several tobamovirus species are known to infect tomatoes and peppers. The symptoms usually include chlorotic mottle, distorted or mosaic leaves, and small, discolored, deformed fruits; these symptoms generally affect both the quantity and quality of production. − The virus particles are produced to a high titer in susceptible host species and are very stable; thus, the symptom severity varies with virus strain and host genotype. − Seeds from tobamovirus-infected plants can easily be externally contaminated with the virus, which spreads the viruses through the international trade of pepper and tomato seeds that are unknowingly contaminated. , …”