disease in seed

[TightenUp]

what specific diseases have the potential of being passed through contaminated seeds?

[Tom Wagner]

This is a topic always there to stir up controversy.


Over twenty years ago I fought a battle with TMV..Tobacco Mosaic Virus..in tomato breeding plots in both greenhouse and field production areas. The transmission was largely mechanical spreading from plant to plant. Here is a sample of what the plant and fruit look like with TMV.



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http://www.apsnet.org/edcenter/intro...ccoMosaic.aspx

A wounded plant cell provides a site of entry for TMV. The virus can also contaminate seed coats, and the plants germinating from these seeds can become infected.
TMV can easily overwinter on the seed coat, thus providing an inoculate source for the next planting cycle. Therefore, it is important to treat TMV-contaminated tobacco seed with a 10% solution of trisodium phosphate for 15 minutes.

My contract with the company I worked for necessitated my breeding resistant lines ot TMV but the suggestion that I do some seed treatment by colleagues brought me to the measures of hot water treatment, TSP treatment and chlorine rinses. I even used Hcl in some cases. My experience was that freshly extracted tomato seed from infected plants actually transmitted the virus to the new seedlings. Waiting a few months of aging...very few seemed infected. To this day I treat my tomato and even potato seed with the combination of hot water/TSP/chlorine. I also devoted a significant part of my work to introgressing a couple of strains of TMV resistant genes into a large population of breeding lines.

Some studies indicate that TMV transmission in tomato seed is not the problem once thought. The article below

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Another seed borne problem is with common beans

Bean common mosaic (BCM) potyvirus resistance is needed in all bean cultivars to
prevent spread of this seedborne virus.

My family has had a bean variety that has been handed down through the generations...in this country since 1888 and before that in Graben Neudorf, Germany.
I noticed a few plants that my Grandmother Kaighin grew back in the early 50's that look mottled and had very few pods on the vine. I kept the seed alive by growing each year by growing out the best seed from the healthiest vines but still could see the virus. For years I would put a single bean in the ground in isolated areas and if the bean vine was healthy I would save the beans from that single plant and grow it the next year in yet another isoated area. If no individual vines expressed the virus I would save that seed. Just last week I planted those beans in single plant rows of six outstanding virus free lines from last year.

Sorry, I didn't mean to write so much but it might serve a purpose to the readers who want to know more about saving their own seed and whether or not the seed is contaminated.