So in 2022 one of my sub-projects was to breed in some resistance to the ToBRFV virus a new virus rapidly spreading worldwide for which there is or was until recently no existing resistance in domestic tomatoes.
A research paper with a list of resistant wild accessions was published and I saw it shared on Facebook. It is also important because it gives us an idea of just how rare resistance is even in wild tomatoes. From 636 wild species accessions they found about 31 resistant accessions or about 5 per 100 accessions.
Winter of 2021-2022 I was able to request this toBRFV resistant accession from the USDA ARS-GRIN which is on the list.
LA1375 PI 365967 Solanum pimpinellifolium
I’ve grown out some seed but not much because of poor pollination in the greenhouse. Plants got enormous though.
I’ve managed to successfully cross it with my Mission Mountain Morning F1 line within my Mission Mountain project, so I have F1 seed for that to grow next year. I would like to share the F2 generation widely- ideally through Experimental Farm Network.
I expect the F1 to be a red currant tomato and not really very interesting.
I have another accession Solanum chilense LA1932 from that same published work that so far, I have failed to grow successfully. 2022 was the closest. The plants got big but just as they flowered it froze inside the mostly unheated greenhouse. I might need some heated greenhouse space or another proper growing area to get it to set seed and live long enough to replenish my seed supply. Originally, I wanted this accession because it is known to be easier to cross with domesticated tomato then other peruvianum group wild tomato species.
There is an existing thread about this here:
Importantly a number of large tomato breeding companies who both started earlier and breed faster by growing multiple generations a year and genotyping them have already introduced commercial resistant varieties to large growers in at least Israel, Italy, and Mexico. I expect that somewhere in the tomato sections at the grocery stores there are a few resistant varieties already available as fresh fruit. In a worst case scenario we could propagate resistant plants from that, but I suspect that resistant seed packets will soon become available to home gardeners.
However, we get some resistance genes the next step is huge: we need to cross them into large numbers of heirloom varieties just as Carol Deppe suggested is necessary for Late Blight resistance.
It is important not to spread the virus as well- one of the more dangerous things towards making the spread more rapid is reciprocal international tomato seed trades.