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Nova Scotia

i was woundering if all the inbreeding of these fruit are causing the more and more comman mutations to the plants. i know it affects anamials and will eventually kill them. could this happen to our ag's if we never introduce new genetic material every once and a while?

10/23/2003 12:30:27 PM

Edmonton, Canada

I was wondering the same thing.

10/23/2003 2:16:05 PM

Itzetown City

Inbreeding can lead to a more of mutations, which presupposes however, the Mutants into the breed is merged. Since Mutants are often not survivable or infertile, the probability = mutations is more by inbreeding = is less. A most frequent cause for mutations are radiation and chemicals.
Are mutations really more frequent with AG or them only more frequently observed? Because the AG are more exactly examined than for example beans or peas?

10/23/2003 3:27:50 PM

Itzetown City

How many chemicals takes a AG grower to his plants? I´m sure pesticides may cause mutations.

10/23/2003 3:31:34 PM

Deer Park, WI

Inbreeding does not cause mutations. Mutations are the result of damaged or altered DNA. These are mostly random, but can be cuased by nasty chemicals (NONE of which we commonly use in our gardens), and sunlight. Mutations can manifest as both good and bad. However, they usually carry a negative connotation. You may be confusing mutations with recessive traits, which is a whole 'nuther ball o wax. Recessive traits can be good and bad as well. But, and this is one huge But, growers are doing their own genetic selection for superiority whether they know it or not. Therefore, bad mutations and recessive genes are weeded out of the gene pool, cuz no one grows the duds. Make sense? we keep growing the best of the best. If the 582 produces a pile of turd pumpkin, the grower wont distribute the seeds, and the growers wont grow them. Another 582 produces a pumpkin that weighs, oh lets say 1458lbs, then people grow this sucka. WHy? cuz that mofo is huge. GENETICALLY SUPERIOR. We have just weeded out poor genetics without knowing it. Why do you think weights go up every year, and we are constantly breaking site, state, and world records? Look at our history of top weights and you'll see a logarithmic curve of growth. Thats unheard of anywhere else in the plant world. WE are doing our own selection for superior genetics. We cant kill our AG's. WHy? Because the best survive.

10/24/2003 9:14:39 AM

Stouffville

How are recessive genes that are linked to size weeded out of the genepool? Is it because most growers want to grow seeds that consistently produce biggies as opposed to one that may throw only a few huge ones?

10/24/2003 9:51:09 AM

Ljubljana, Slovenia

There are two effects of inbreeding:
First (short term effect), you get more homologues (pairs) of recessive genes. This means that more recessive genes are expressed and since they are usually defective the function of that gene is lost or weaker (e.g. genes for orange color).

Second (long term effect), homologues of genes defective in important functions result in death and therefore elimination of such genes in the progeny. By this way repetitive inbreeding “cleans” the “bad” genes.

I think that AGs are already in the second phase that is they are mostly cleaned of the bad genes. But still it is important to cross different lines to get better combinations of good genes.

10/24/2003 10:52:28 AM

Ljubljana, Slovenia

Some more:
Evolution works under selection pressure that selects among different genes. Bigger diversity of genes means more flexibility. Some of the genes in the gene pool may be “no good” (defective) but remain in the gene pool if they are recessive and there is not much inbreeding. The importance of such genes is when environment changes and some of them may become advantageous.
Consider an example: once upon a time all the pumpkins were orange because they signaled animals which perpetuated their seeds when they are ripe and ready to eat. In this way animals were able to spare the green fruits and let the seeds to mature. Mutations in orange color existed but were expressed seldom because they where recessive. Then a change in the environment occurred. Most of the animals extinct and the most important perpetuator of the pumpkin seeds became a man. Man is cleaver being so he thought why not to grow green pumpkins instead of orange ones? So he did and called them squash. The result was that the recessive genes that where once “no good” became “good” and thanks to them the pumpkin species was able to adapt to changed environment.

We have to consider that in nature the environment changes and therefore also the selection pressure changes. In AGs the selection pressure is constant and basically equals the size of the fruit. So the recessive “no good” genes are not important for the survival of AGs unless we change our mind and start to grow the smallest possible pumpkin :-

Jernej

10/24/2003 10:52:45 AM

Stouffville

has anyone figured out which traits are recessive in giants?

10/24/2003 11:03:50 AM

Ljubljana, Slovenia

Genes that give green color are supposed to be recessive. That means that if you inbreed the pumpkins you get some squash in the progeny. Since squash does not have other traits different than pumpkin I guess that there are not many other recessive genes in AG gene pool.

A gene is recessive if it is in combination with a dominant gene which overwhelms it. During AG breeding some of the dominant genes may have been eliminated. In this case a recessive gene in no longer recessive. So things could get complicated…

That’s enough from me. Forgive me for the monologues but it is the first day of snow over here.
Jernej

10/24/2003 11:52:41 AM

Stouffville

we woke up with a light dusting of snow here in stouffville ontario canada too

10/24/2003 12:09:07 PM