...that's been on the market since at least the post-WWII era--they're called "F1 hybrid" seeds. F1 in genetics refers to the first generation of offspring. These seeds exhibit "hybrid vigor", meaning they tend to exhibit more robust growth and fitness. Hybridization also can be used to confer various highly-desired traits to the organism, e.g. disease resistance in tomato plants. The drawback: F1 seeds don't breed true, so that if you save seeds from this year's crop, next year's won't be the same. (They're not genetically stable, so you get back the parent plants plus some other recombinations).
Seed companies love F1 seeds because of this--you have to buy new ones when you run out because seed-saving doesn't work. They're also much cheaper to produce than GMO "terminator" seeds, though I didn't know those had never made it to market here. I guess the power of the farm lobby is strong enough in the USA. I wonder if they have been marketed elsewhere.
The alternative to F1 hybrids is the old-fashioned open-pollinated plant, often called an "heirloom" especially when it comes to tomatoes. They usually aren't as disease-resistant or robust (no hybrid vigor), but they have other desirable traits. Heirloom tomatoes are quite special and unique, for example. You can save seeds from heirloom plants, and they will breed true for many generations--however, unless you prevent cross-pollination, even heirloom plants will naturally hybridize through all the pollinators in the environment (e.g. bees/wasps, butterflies, hummingbirds).
Privatizers like Eloon hate "heirloom" seeds because most countries' patent laws (including ours) prohibit the patenting of open-pollinated or otherwise naturally-occurring plants. I wonder if Eloon is thinking about getting into the agriculture business. Or maybe he just can't help himself, like many end-stage capitalists: if we can't make big money from it, why not destroy it? 
https://en.wikipedia.org/wiki/F1_hybrid
https://en.wikipedia.org/wiki/Heterosis
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