Can seeds be harvested and saved from tomatoes infected with early blight? Will the desease be carried over to the next generation of tomato plants grown from these seeds?
I have saved seeds from many hundreds of plants that had Early Blight ( A.solani) and as long as you ferment the seeds it lessens the presence of the spores on the seed exterior. This was shown by Dr, Helene Dillard. And since infection is a quantitative process the lessened amount of pathogens on the seed coat the less likely that fungal diseases will be seedborne.
Those bacterial and viral pathogens studied to date exist in the seed endosperm and for the bacterial ones only hot water treatment can be effective and even then there can be a loss of seed viability. Hot water tratment is not advised for the home grower. So no method associated with seed coat removal can do anything for the bacterial and viral diseases.
And I mention fermentation specifically b'c no data exists to attest to the efficacy of oxidative methods in lessening the pathogen burden on TOMATO seed coats and a search here will bring up threads about that.
Commercial seed is processed either by fermentation or acid, but again, acid treatment is not for the home grower.
TSP ( tri-sodium Phosphate) can be used to inactivate TMV but since TMV is no longer a major problem for the home growers and TSP is also very caustic, I don't suggest it, again, for the home grower.
Hope that helps.
Thank you, Carolyn! Very informative and helps a lot!