If an Heirloom is an Heirloom, What's a Hybrid?

marc_groleau · February 8, 2012

Sorry for the ridiculous tittle. I don't mean it to be so.

This is how I understand it: One develops an heirloom by crossing at least two open pollinated varieties and then selectively growing out seeds from the cross for several generations until a repeatable outcome be expected from any of the seeds.
My understanding of a hybrid is 2 crossed varieties that haven't been grown out selectively over generations.That is why saving seeds from a hybrid will result in mixed outcomes. Does that mean that one cross pollenation of 2 different varieties will produce a repeatable outcome for every first generation? In otherwords, how does one produce seeds for a Big Beef hybrid for example, repeatably year after year?

I hope my question is comprehensible.

Regards,

Marc

**nctomatoman** · February 8, 2012

Marc, for any available hybrid variety, you are purchasing seed that came from fruits that were formed by doing the actual cross. The labor involved is a factor in the higher cost of hybrid varieties.

Selling hybrids of tomatoes didn't begin until the 1940s. Prior to that, hybrids were done by companies, but only as starting points to varieties they would release after selecting and stabilizing for years.

Petronius_II · February 9, 2012

Another part of the creation of a modern F1 hybrid, as I understand it, is that both parent populations are heavily inbred for several generations before they're crossed.

That way the breeder knows the parent varieties are quite stable, and that's why modern F1 hybrids are so predictable. After all that inbreeding (which is the same as what you're doing if you bag blossoms before and after ensuring self-pollination,) the parent plants are likely to be homozygous (same gene on both chromosomes) for all the desired traits. So that's why "one cross pollenation of 2 different varieties will produce a repeatable outcome for every first generation."

marc_groleau · February 9, 2012

Wow! Great answers even I can understand.

Thanks, you folks here really know your stuff.

coloken · February 9, 2012

Quote:

Originally Posted by Petronius_II

Another part of the creation of a modern F1 hybrid, as I understand it, is that both parent populations are heavily inbred for several generations before they're crossed.

That way the breeder knows the parent varieties are quite stable, and that's why modern F1 hybrids are so predictable. After all that inbreeding (which is the same as what you're doing if you bag blossoms before and after ensuring self-pollination,) the parent plants are likely to be homozygous (same gene on both chromosomes) for all the desired traits. So that's why "one cross pollenation of 2 different varieties will produce a repeatable outcome for every first generation."

Thank you for saying it so perfectly. I was a life time cattle grower and what you describe fits there too. If not from two specially grown lines, but like two varieties crossed, it is know as a "cross breed". Cross breeds are very popular in the cattle business but are not known as hybrid.

rockhound · February 9, 2012

Marc~ True Heirlooms don't have to start with any intentional cross. I would even say most did not. Somebody grew a tomato or other veg that they really liked and saved the seeds and planted them for many years. It could be an individual or a family. True heirlooms weren't sold commercially until recently. They were all just local. Now we have folks in Florida (for instance)trying to grow heirlooms from VA and not getting good results and say they won't try heirlooms again, lol. The plant was adapted to VA for many generations, it's kind of a duh moment. Totally different climate.
ETA: The characteristics of a variety can drift over years of selecting from the exact same seeds because the person saving seeds likes one trait or another. If I prefer red-red tomatoes, I will tend to save seeds from the reddist in my patch. Same for large, or earliest or whatever that seed-saver selects for, intentional or not. Then there's the whole "genetic bottleneck" thing. Someone with a small garden saved seed for many years from the first plant by the gate because that was convenient. Say they only have 16 plants anyway. Many traits can fall by the wayside for no good intentional reason, just dumb luck.

February 8, 2012	#1
marc_groleau Tomatovillian™ Join Date: Jan 2012 Location: Rhode Island Posts: 444	If an Heirloom is an Heirloom, What's a Hybrid? Sorry for the ridiculous tittle. I don't mean it to be so. This is how I understand it: One develops an heirloom by crossing at least two open pollinated varieties and then selectively growing out seeds from the cross for several generations until a repeatable outcome be expected from any of the seeds. My understanding of a hybrid is 2 crossed varieties that haven't been grown out selectively over generations.That is why saving seeds from a hybrid will result in mixed outcomes. Does that mean that one cross pollenation of 2 different varieties will produce a repeatable outcome for every first generation? In otherwords, how does one produce seeds for a Big Beef hybrid for example, repeatably year after year? I hope my question is comprehensible. Regards, Marc

February 8, 2012	#2
nctomatoman Tomatoville® Moderator Join Date: Jan 2006 Location: Hendersonville, NC zone 7 Posts: 10,385	Marc, for any available hybrid variety, you are purchasing seed that came from fruits that were formed by doing the actual cross. The labor involved is a factor in the higher cost of hybrid varieties. Selling hybrids of tomatoes didn't begin until the 1940s. Prior to that, hybrids were done by companies, but only as starting points to varieties they would release after selecting and stabilizing for years. __________________ Craig

February 9, 2012	#6
rockhound Tomatovillian™ Join Date: Dec 2011 Location: Tennessee Posts: 285	Marc~ True Heirlooms don't have to start with any intentional cross. I would even say most did not. Somebody grew a tomato or other veg that they really liked and saved the seeds and planted them for many years. It could be an individual or a family. True heirlooms weren't sold commercially until recently. They were all just local. Now we have folks in Florida (for instance)trying to grow heirlooms from VA and not getting good results and say they won't try heirlooms again, lol. The plant was adapted to VA for many generations, it's kind of a duh moment. Totally different climate. ETA: The characteristics of a variety can drift over years of selecting from the exact same seeds because the person saving seeds likes one trait or another. If I prefer red-red tomatoes, I will tend to save seeds from the reddist in my patch. Same for large, or earliest or whatever that seed-saver selects for, intentional or not. Then there's the whole "genetic bottleneck" thing. Someone with a small garden saved seed for many years from the first plant by the gate because that was convenient. Say they only have 16 plants anyway. Many traits can fall by the wayside for no good intentional reason, just dumb luck. Last edited by rockhound; February 9, 2012 at 03:04 PM. Reason: incomplete.

February 9, 2012	#3
Petronius_II Tomatovillian™ Join Date: Jan 2012 Location: Albuquerque, NM - Zone 7a Posts: 209	Another part of the creation of a modern F1 hybrid, as I understand it, is that both parent populations are heavily inbred for several generations before they're crossed. That way the breeder knows the parent varieties are quite stable, and that's why modern F1 hybrids are so predictable. After all that inbreeding (which is the same as what you're doing if you bag blossoms before and after ensuring self-pollination,) the parent plants are likely to be homozygous (same gene on both chromosomes) for all the desired traits. So that's why "one cross pollenation of 2 different varieties will produce a repeatable outcome for every first generation."