Jointless tomato plants

[Jeannine Anne]

Can someonee explain to me in simple laymans terms what this is all about.

I have one variety that is jointless, how does it affect growing etc etc and why are they jointless.

Please don't get technical, I have looked on the net and ..........well I came here for the simplified version

XX Jeannine

[cornbreadlouie]

I believe. And somebody I'm sure will correct me if I'm wrong.

You're missing the term "pedicel" to go with "jointless". Unless this is something different?


Pedicels are those knobs that grow on the stem right above the tomato. Usually where you pull it off the plant.

A tomato plant with jointless pedicels won't have that little knob, so you will either have to cut it or pull the little "crown" off, leaving just the tomato.

I think I read it's mostly useful for mechanical harvesting, so they just get the tomato and there's no plant parts to poke holes in the fruit as they pile up. I guess for softer varieties it would also be useful if you were going to stack them or something.

Sorry I can't explain it better, I'm sort of an idiot.

[Jeannine Anne]

I think you did very well, it makes perfect sense now..thank you so much XX Jeannine

[rockhound]

I didn't know there other varieties that were jointless but back in the late 80's I grew "Bragger" tomatoes. Don't remember the source and it was before I saved seed as a matter of course, so they were lost. Tomatoes were huge but had to be cut off the vine with side-cutters since the vine was also thick. Anybody know what the name Bragger was changed to?

[carolyn137]

Originally Posted by rockhound

I didn't know there other varieties that were jointless but back in the late 80's I grew "Bragger" tomatoes. Don't remember the source and it was before I saved seed as a matter of course, so they were lost. Tomatoes were huge but had to be cut off the vine with side-cutters since the vine was also thick. Anybody know what the name Bragger was changed to?

The name hasn't been changed and there are seed sources:

http://t.tatianastomatobase.com:88/wiki/Braggar

[ChrisK]

Since you asked why they are jointless here is the biological reason.

Jointless tomatoes carry a mutation in a gene called a MADS box protein. You can think of a MADS box protein as a master controller in that it turns on or off other genes. MADS box genes often control organ development such as flowers.

In this case the defective MADS box gene is unable to turn on or off the other genes that are responsible for forming that knob Louie describes. That knob is actually a specialized structure that is intended to break in "normal" tomatoes. The picture below shows a jointless and normal flower.

Chris

[travis]

I've always thought this particular jointless, elongated plum breeding line from North Carolina State University's program was beautiful:

http://www.ces.ncsu.edu/fletcher/pro...s/NC-EBR-7.jpg

[rockhound]

Thanks, Carolyn. As always, you're very helpful. Too bad it's so late and I started what few plants I have room to grow or I would order seeds. I think my searches were mis-spelled too.

[salix]

Probably a silly question, but - do tomatoes with the jointless pedicels ripen indoors as well as jointed varieties? I guess my question is really "is the jointed pedicel the abscission zone where water is allowed in, but other components blocked?"

[ChrisK]

There have been studies of jointed vs jointless tomatoes. I've not done an exhaustive literature search though. Not to say such studies don't exist, but I didn't find anything about ripening post harvest in a quick search.

Here are some primary literature references in case you really want to dig into tomato pedicels!

http://jxb.oxfordjournals.org/content/54/381/317.long
http://www.springerlink.com/content/u50j127840185310/
http://www.plantphysiol.org/content/158/1/439.abstract

[salix]

Chris, thank you for posting those links, fascinating reading.

[travis]

I think since jointless pedicel is used in tomato hybrids designed for mechanical harvest/shipping-to-market, that the jointless pedicel characteristic often is paired with high crimson and uniform ripeness (as well as in some cases rin-ripeness inhibitor), particularly in the fresh market, plum saladette and salsa tomatoes. So, the fruit ripens satisfactorily in shipping and holding to the uniform, full red finish you see at the grocery store.

[ChrisK]

Quite welcome. Reading another unrelated thread here got me wondering if there would be much interest in a "journal club" of sorts. I'm thinking along the lines of a discussion of primary literature papers made accessible to the layperson. Maybe even a separate forum for them? Would have to be open access papers for copyright reasons.

Just a thought.

Originally Posted by salix

Chris, thank you for posting those links, fascinating reading.