Questions about Parthenocarpic types

bigbubbacain · December 30, 2009

Does anyone know if parthenocarpic varieties are necessarily considered GMO? More specifically, were any of these types arrived at through cross pollination or conventional hybridization procedures?

Tania · December 30, 2009

There are many parthenocarpic varieties of tomatoes are not GMO:

Many were bred by Oregon State University, for the cool spring conditions of coastal PNW - they would set fruit without pollenization:

- Oregon Spring
- Oregon Star
- Siletz
- Gold Nugget
- Saucey

All of the above are open-pollinated varieties.

I also know of another Parthenocarpic variety (but not sure of its origin) - Oroma (offered by Territorial seed Company)

Tania

bigbubbacain · December 30, 2009

Thanks Tania!

I'm not at the point yet where I feel I will need to use these types of tomatoes, but I'm considering parthenocarpic Zucchini and Cucumbers. How can I determine which ones are GMO?

Tania · December 30, 2009

I know very little about Zukes and cucumbers... as I am mainly a tomato gal

Sorry...

Tania

mjc · December 30, 2009

There is a GM yellow crookneck, but it is mosaic virus resistant or something. As far as I know there aren't any other cucurbits that are approved for use or being sold

Wi-sunflower · December 30, 2009

Territorial used to have a couple of parthenic zucchini that i bought for greenhouse production many years ago. The seeds were quite expensive and I don't know what is still out there.

As far as cucs go I don't know if the so-called "seedless" are truly parthenocarpic or not. The thing is they are primarily female flowered and as long as they are grown in a closed or isolated area, they will make the fruit without having seeds. I've grown a few of them long ago too. Same as with the zuccs, the seeds are expensive.

None of the varieties I knew about were GMO stuff at all.

Carol

bigbubbacain · December 31, 2009

Thanks Carol!

Expensive seeds are a small price to pay.

**carolyn137** · December 31, 2009

As to parthenocarpic tomatoes, there are naturally occuring ones as well as ones that are bred.

All a hybridizer has to do is to knock any of the genes involved in pollen formation and without viable pollen parthenocarpy occurs.

But parthenocarpic varieties do have some problems. Because fruit formation occurs in the absence of fertilization there are no to few seeds and that's not what a seed saver needs or wants. In addition fruits can be malformed b'c fruit formation is not normal.

Folks who spray blossom set with abandon are also inducing parthenocarpic fruits b/c Blossom Set, depending on the specific brand, has a plant hormone in it, the most common one being IAA ( indole acetic acid) that allows for fruit formation in the absence of fertilization.

Blossom Set was devised to be used to help with fruit set in areas where it's too COLD for normal fertilization to occur. Dr. James Baggett, now retired, bred the many parthenocarpic varieties he did, he being at Oregon State U and the PNW being and area that does have it's problems with COLD Spring weather.

So if temps are normal for self fertilization then Blossom Set is useless.

Edited to add that I made a goof above on kocking out pollen genes and inserting something else. Will be back after I check it out but don't have time now. All else is OK.

http://dev.biologists.org/content/125/1/107.full.pdf

Reedited to add I found the info I needed, the link is above. The tomato parthenocarpy gene pat has to be inserted and so it's not anything GMO. And forget about my saying that a pollen gene has to be knocked out. The gene pat was isolated from tomato accessions that were naturally parthenocarpic so by inserting that gene in a particular tomato variety it changes that variety to a parthenocapric variety.

Wi-sunflower · December 31, 2009

I see Territirial does list 2 zucchini that are parthenocarpic. From what I could find in a search they are Tompson and Morgan varieties and I found them at T&M for a better price. I might try some this spring if I have money for the seed by then. Things are a bit tight right now.

Here is a link to a pdf of a trail of several varieties that Nebraska did a couple of years ago. http://hort.unl.edu/hodges/parthenoc...cchini2008.pdf

Carol

December 30, 2009	#1
bigbubbacain Tomatovillian™ Join Date: Apr 2007 Location: Zone 9 Texas, Fort Bend County Posts: 436	Questions about Parthenocarpic types Does anyone know if parthenocarpic varieties are necessarily considered GMO? More specifically, were any of these types arrived at through cross pollination or conventional hybridization procedures?

December 30, 2009	#2
Tania Tomatovillian™ Join Date: Jan 2006 Location: Anmore, BC, Canada Posts: 3,970	There are many parthenocarpic varieties of tomatoes are not GMO: Many were bred by Oregon State University, for the cool spring conditions of coastal PNW - they would set fruit without pollenization: - Oregon Spring - Oregon Star - Siletz - Gold Nugget - Saucey All of the above are open-pollinated varieties. I also know of another Parthenocarpic variety (but not sure of its origin) - Oroma (offered by Territorial seed Company) Tania __________________ Tatiana's TOMATObase

December 30, 2009	#4
Tania Tomatovillian™ Join Date: Jan 2006 Location: Anmore, BC, Canada Posts: 3,970	I know very little about Zukes and cucumbers... as I am mainly a tomato gal Sorry... Tania __________________ Tatiana's TOMATObase

December 31, 2009	#8
carolyn137 Moderator Emeritus Join Date: Jan 2006 Location: Upstate NY, zone 4b/5a Posts: 21,169	As to parthenocarpic tomatoes, there are naturally occuring ones as well as ones that are bred. All a hybridizer has to do is to knock any of the genes involved in pollen formation and without viable pollen parthenocarpy occurs. But parthenocarpic varieties do have some problems. Because fruit formation occurs in the absence of fertilization there are no to few seeds and that's not what a seed saver needs or wants. In addition fruits can be malformed b'c fruit formation is not normal. Folks who spray blossom set with abandon are also inducing parthenocarpic fruits b/c Blossom Set, depending on the specific brand, has a plant hormone in it, the most common one being IAA ( indole acetic acid) that allows for fruit formation in the absence of fertilization. Blossom Set was devised to be used to help with fruit set in areas where it's too COLD for normal fertilization to occur. Dr. James Baggett, now retired, bred the many parthenocarpic varieties he did, he being at Oregon State U and the PNW being and area that does have it's problems with COLD Spring weather. So if temps are normal for self fertilization then Blossom Set is useless. Edited to add that I made a goof above on kocking out pollen genes and inserting something else. Will be back after I check it out but don't have time now. All else is OK. http://dev.biologists.org/content/125/1/107.full.pdf Reedited to add I found the info I needed, the link is above. The tomato parthenocarpy gene pat has to be inserted and so it's not anything GMO. And forget about my saying that a pollen gene has to be knocked out. The gene pat was isolated from tomato accessions that were naturally parthenocarpic so by inserting that gene in a particular tomato variety it changes that variety to a parthenocapric variety. __________________ Carolyn Last edited by carolyn137; December 31, 2009 at 01:52 PM. Reason: goofed, then degoofed

December 30, 2009	#5
mjc Tomatovillian™ Join Date: Jun 2009 Location: WV Posts: 603	There is a GM yellow crookneck, but it is mosaic virus resistant or something. As far as I know there aren't any other cucurbits that are approved for use or being sold

December 30, 2009	#6
Wi-sunflower Tomatovillian™ Join Date: Nov 2008 Location: Wisconsin Posts: 2,591	Territorial used to have a couple of parthenic zucchini that i bought for greenhouse production many years ago. The seeds were quite expensive and I don't know what is still out there. As far as cucs go I don't know if the so-called "seedless" are truly parthenocarpic or not. The thing is they are primarily female flowered and as long as they are grown in a closed or isolated area, they will make the fruit without having seeds. I've grown a few of them long ago too. Same as with the zuccs, the seeds are expensive. None of the varieties I knew about were GMO stuff at all. Carol