Israeli companies NRGene and Philoseed are working together to create varieties resistant to Tomato Brown Rugose Fruit Virus (ToBRFV) – often called ‘Tobamovirus’. NRGene’s genomic AI solutions will be used for marker-assisted integration of ToBRFV resistance into Philoseed’s philiadvanced commercial tomato varieties.
The identified tomato resistance source for ToBRFV by Philoseed (patent filed) will be mapped using an ultra-density genetic map. A set of DNA markers covering the entire tomato genome will then be used to introduce the ToBRFV trait efficiently into Philoseed’s diverse tomato varieties while minimising introgression of additional genetic components from the TBRFV resistant tomato donor.
NRGene’s genomics, coupled with Philoseed’s breeding qualities, will accelerate the breeding process for ToBRFV resistance and the release of new commercial varieties is expected during 2022. Resistant tomato lines and the DNA marker sets will be available commercially to all tomato seed companies for fast trait integration.
What is ToBRFV?
Tomato brown rugose fruit virus (ToBRFV) is a member of the genus Tobamovirus. However, unlike other tomato infecting members of the genus, such as tobacco mosaic virus (TMV) and tomato mosaic virus (ToMV), ToBRFV can overcome the Tm-2 2 resistance gene. This means that tomato varieties which are resistant to TMV and ToMV will be susceptible to infection with ToBRFV. Tomato plants infected with ToBRFV yield fruits of extremely poor quality and low commercial value.
ToBRFV was first discovered infecting tomato crops in Jordan and Israel around 2014-2015, before subsequently spreading to other tomato growing regions around the world, including China, France, Greece, Italy, Mexico, the Netherlands, Spain, Turkey and the UK. There have also been outbreaks in Germany and the USA.
As with other tobamoviruses, ToBRFV is readily spread via contact transmission and mechanical means, as well as being seed transmissible, impacting seed shipment from infected countries. The virus has also been shown to be transmitted by bumblebees during pollination. The virus is environmentally stable and also relatively heat tolerant making control of the pathogen challenging.
Economic impact
ToBRFV can infect up to 100% of a crop (reported in Jordan), and yield losses of between 25 and 70% have been reported, largely due to the fruit being unmarketable, and the loss of production period as plants reduce in vigour and die prematurely, according to a factsheet prepared by the UK’s Department for Environment, Food and Rural Affairs (DEFRA).
Additional costs can be incurred through removal of infected crops and cleaning of the glasshouse. However, it is possible for plants to show no obvious symptoms and yet still be infected, and the susceptibility of the crop is dependent on the variety, cultural practices and the climate, with glasshouse crops expected to be more susceptible than outdoor grown crops, as there is more handling and spread via mechanical transmission.
Collaborative solution
NRGene’s advanced multi-purpose breeding platform is an AI cloud-based solution for managing the full genomic diversity of species. It can analyze unlimited volumes of genomic data, enabling scientists and breeders to easily relate genomic sequences with beneficial traits, making genomic selection and trait mapping much more productive. Data use is accelerated, making breeding both faster and more cost effective.
Philoseed has expertise and vast experience in combining its unique tomato genetic material to enable the identification of extremely strong resistance to the ToBRFV. Crossing this resistance source with its advanced commercial lines is expected to give Philoseed a significant edge in the markets in which it is active. Philoseed has already started backcrossing it into its leading lines.
“This collaboration will enable us to accelerate the integration of the genomic region for our unique ToBRFV resistance source into commercial genetic background using markers-assisted breeding techniques,” said Dr. Ehud Kopeliovitch, breeding manager at Philoseed and an internationally recognised tomato breeder. “It will let us launch new tomato varieties with strong resistance for this virus in a short period of time”.
Amit Schwarz, CEO & marketing manager at Philoseed, added: “As soon as Philoseed launches this new resistant variety series, we will be able to increase our share in targeted markets.”
“We are excited to collaborate with Philoseed and jointly fight the Tobamovirus spread,” concluded Dr. Gil Ronen, NRGene’s CEO. “NRGene’s long-term investment into building genomic tools in tomato, including the first pangenome for fresh tomatoes, has now been repaid by our ability to map and introduce this important trait in record time.”
A useful 2020 webinar about Tomato brown rugose fruit virus by the UK’s AHDB Horticulture. The UK’s first case of the virus arrived in 2019.
