Hybrids
 

I want to know how crossing two OP plants can create a hybrid which has resistance to disease. Where does this resistance come from?

From one of the parents. Also usually hybrids have a better vegetative growth that can outgrow disease better, which may give impression of resistance.

Try as many crosses as you can.You might get pretty impressive results.Cross varieties that are as different from each other as possible.
Note that crossing a small fruited variety with larger fruited ones gives a plant with fruit size resembling the smaller one more so than the larger,smaller fruit size is highly dominant.

Crosses are fun. When I think I've learned something - something else happens. I saved seeds from Oranje Van Goeijenbier (OVG) in 2015. A typical sized orange cherry tomato a little larger than the small tomato in the picture. It crossed and the OVG plant this year is growing the larger tomatoes in the picture. They're not even orange anymore. :lol::?

[QUOTE=uzlaguzla;642670]I want to know how crossing two OP plants can create a hybrid which has resistance to disease. Where does this resistance come from?[/QUOTE]

Known as hybrid vigor.
It is common in animals many times too.
And the reason why many mutts, cats and dogs are more healthy than purebreds.

The breeding stock that the seed companies use is top secret stuff. If they have an op line with a disease resistance, they would not release something like that to the public. It's a trade secret.

[QUOTE=Cole_Robbie;643033]The breeding stock that the seed companies use is top secret stuff. If they have an op line with a disease resistance, they would not release something like that to the public. It's a trade secret.[/QUOTE]

It's that serious? Pfft this is one of the reasons I'm trying to develop my own hybrids.They can have their dirty...pure lines.Luckily we have thousands of heirloom varieties & wild species avaliable many of which might have hidden resistances and beneficial traits.

The thing is only one person has to know the parents of a hybrid or it is locked up in a vault someplace.
The workers doing the breeding dont have to know anything about what they are breeding.

Just like those folks back in WWII that worked on the atomic bomb.
Here watch this gauge and turn this knob so it stays between 100 and 200.