Naked Science Forum
Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: CliffordK on 10/07/2013 11:00:10
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The majority of our fruit trees are being propagated with cuttings and grafts.
Some types of fruit such as grapes and oranges are being bred to be seedless, and thus can only be propagated with cuttings and grafts.
So, are the trees immortal? I.E. one just needs to take a new cutting, and one can start a clone, and one could potentially repeat the process indefinitely.
Or, does the tree, like humans, have a finite lifespan. at which point, the trees would no longer be able to produce viable fruiting grafts???
One of the reasons for grafting is that apparently many trees grown from seed do not produce fruit until they are about 8 years old. By grafting "mature" branches onto the seedling, the tree will start fruiting much earlier. So, if there is a fundamental difference between starts from seedlings, and starts from young grafted trees, then would the grafts continue to age independent from the number of times cuttings are taken and propagated.
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An interesting question, Clifford.
The Guinness Book of Records has this 400+ year old vine (http://www.slovenia.info/?naravne_znamenitosti_jame=2789) listed as the oldest in the world. It still produces 35 - 55kgs of fruit a year.
A modern vinyard would not want to be dealing with a vine such as this, they want vines which can be easily harvested. The same goes for any commercial fruiting crop. Trees, vines and bushes are grown with harvesting in mind and are pruned annually to keep them in good shape. Eventually, the plant will need to be replaced, as further prunning will reduce the crop. Cuttings are the preferred means of propagation for speed of fruiting and to maintain the variety.
It would be my guess that a tree/bush/vine could be propagated over & over again, ad infinitum, with no detrement to the new plant's fruiting, but that is my guess and a guess only.
Perhaps there is a long family held business in the fruit or wine trade which could confirm that they are still taking cuttings from an original plant of hundreds of years ago.
Does anyone know of a 50th generation propagated vine? Again, my guess is that many vines are indeed propagated from very long lines of propagated stocks.
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"Immortal" does not mean "unchanging".
Over the years, many mutants (http://en.wikipedia.org/wiki/Red_Delicious#Sports_.28mutations.29) have occurred in fruit trees (eg a branch which has different-coloured apples), and if someone liked this "sport", it then became a clone of its own.
These clones could become immortal - or permanent as long as someone has an interest in propagating them (at least bananas (http://en.wikipedia.org/wiki/Banana#Modern_cultivation) can self-propagate).
The risk with mass-cloned crops is that a disease could wipe out an entire cultivar (as happened in the Irish potato famine (http://en.wikipedia.org/wiki/Irish_potato_famine#Blight_in_Ireland)).
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Actually, Mom has two Gravenstein (http://en.wikipedia.org/wiki/Gravenstein) Apple trees, planted a couple of years apart that have distinctive maturation patterns. I suppose if is a 350 year old variety, and still popular, that says quite a bit, and even if it has been repeatedly grafted, one would expect some genetic drift.