I have wondered this before. Tomatoes - if you get a disease on your plants during the season and collect seed from the tomato, will the plants from those seed be more vulnerable to that disease? Right now the plant I am trying to collect from is Butterfly Weed. It was looking so healthy for most of the summer and after it's initial bloom, the foliage started to look bad. yellow and green mottled look on the leaves. Mind you I don't know that it had a disease or if it could have been a deficiency, although going from looking very healthy to not, I don't know. Still after I dead headed it, it pushed out a lot of new foliage, some of it clean. It continued to bloom and now I see multiple seed pods have developed on it and wondering should I pass on those? I have another patch of Butterfly Weed that also has pods and I could collect those.
Anyone have any knowledge about this issue?