I'm kind of confused...you're hoping to induce mutation through stress? and then harvest the mutated seeds and have new phenotypic offspring?

as someone who's been transforming plants for the past two years (not trying to sound like a dick) I'd say you have a very low chance of success with this approach.

there are ways to induce point mutations and screen for mutants...but do you really have room to be growing 1000 plants? genetic alteration and then selection of significant phenotypes takes a LOT of plants, room, lights, nutes, MONEY. high throughput is the only way to achieve anything worthwhile...and the chemicals used to induce mutations are extreme mutagens (obviously) and will hurt you if not used correctly.

I applaud your ambition...but, i'd say just grow your stuff and be happy. genetic alteration is not a simple task.