Here’s a simple method:
“Potato
While usually propagated vegetatively, the potato can be grown from seeds which occasionally form on the plants. Let the seed balls mature, then squeeze the seeds into a bowl. Add water and pour off the floating debris, saving the seeds which sink to the bottom. Grow the same as tomato seedlings.
Some of the smaller nightshades, such as cherry and currant tomatoes, tomatillos, ground cherries etc., can be processed in a blender and treated the same as potato seeds. “
http://www.naturallifemagazine.com/9504/seeds.htm
In a SHTF scenario, it probably doesn’t matter if a saved seed breeds true or not. I have saved and planted hybrid tomato seeds and they sprout and bear. Some of the plants breed true, some don’t and bear true to the progenitors, instead.
I suspect the University/Extension article was speaking to commercial farmers. That’s a whole lot different from personal gardening. For example, I have gotten busy and just placed fresh tomato seeds on a paper towel, no fermentation, no washing. They stuck together, so I pried a few off and planted them, indoors, with bottom heat, in the late winter. They sprouted, they grew, they survived transplanting and they bloomed and set fruit. Back in the 1990s, when our local climate was warmer, I had one variety of cherry tomatoes survive a mild winter and volunteer right where I had planted them the previous year. I think the name was Tiny Millions or something like that.
The original wild fruits were managed and planted and eaten by generations of primitive people. It obviously was done in the past and can still be done, today.
The problem is “occasionally” and my parents planted potatoes from regular seed potatoes all their adult life and I never saw any plant that developed seed pods.
I'll be growing the White Fuseau Sunflower russet potato like tubers that spread on their own and I'll never be without food and can give others the tubers so they can have a plot of food of their own that never goes away.
I'm also planting Egypt Walking Onions that propagate/spread on their own and I'll never be without onions and can give those away for people to start their own. Potatoes and onions cooked together is a good meal when there is no other food.
The White Fuseau is a special food in England and has been for many years. A start of 4-5 tubers is $6.95 and means food forever after.
Egypt Walking Onions is 10 topsets for $7.00 and is onions forever after.
If anyone wants to know where to get these never ending foods, send me a Freepmail.