Can Somebody Explain 'Replicative Fading'?

Rose Genetics Ploidy Level
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1

I have obtained several rose books for a Christmas gift. One of them mentions the concept of ‘replicative fading’. I am rather confused as to what this exactly entails. The book used ‘Peace’ as an example of a rose that has been regarded through reckless duplication via cutting. So, are the cuttings in fact genetically indentical, or not (the text seemed to indicate otherwise…). I want to learn more about this concept - does anyone have any materials to read that they would recommend?

For reference, the book is ‘Right Rose, Right Place’ by Peter Schneider, and the above question comes from p. 148 of the 2009 edition.

2

That’s a great question… I assume they mean that through many years and propagation cycles plants begin to show “drift” / decline in terms of performance, especially if careful attention isn’t given to propagating from just the most representative plants. For part of my Ph.D. I studied performance of side by side grown plants of different growers’ bulbs of ‘Nellie White’ Easter lily. There aren’t very many old cultivars where people have obtained plants from different growers that propagated them independently for many years and grew the plants side by side over time to compare their performance and try to ascertain some of the reasons for the differences. I tried to do some DNA fingerprinting comparing the lilies, but the techniques I tried at the time weren’t robust enough. Here is a link to the article where I grew the plants over two flowering cycles and reported phenotypic data Clonal Variability among Grower Bulb Lots of Easter Lily ‘Nellie White’ in: Journal of the American Society for Horticultural Science Volume 132 Issue 1 (2007)

Ultimately, I learned that in the second cycle of growing and flowering the lilies they performed more similarly, so the variable environments they were grown under before I got the bulbs seemed to play a role in their performance, at least early on as I grew them. In addition, they were all positive for Lily Symptomless Virus and the concentration was quite variable going up and down from year to year for the same grower source and impacted the specific plants performance during that flowering cycle. Although one doesn’t get streaky foliage on Easter lilies typically, it isn’t really symptomless like the name implies. Even after those various components were somewhat accounted for there seemed to be additional factors still contributing to differences between the growers for their ‘Nellie White’ plants. We assumed it could be some form of genetic variability accumulating (epigenetic or mutations). I pollinated the first open flower of every plant and counted the ovules per ovary and the number & percent of seeds that developed normally. The idea is that lines over time that have more mutation tend to be associated with decreased fertility (aka Mueller’s ratchet). There definitely were differences in fertility across the different growers’ bulbs.

It would be great if people did this kind of experiment with ‘Peace’ and other historic roses comparing their phenotype in a very controlled manner trying to partition the different causes and what extent each cause accounts for. I suspect over time transposable elements moving around the genome and landing in various important genes and disrupting their expression, perhaps viruses accumulating in roses, and also just physiological/epigenetic changes in gene expression over time all can contribute to changes that generally lead to less desirable performing plants. These kinds of experiments take a lot of time and energy and ultimately just lead people to propagate from the nicest most representative plants for a practical solution anyways and blame less than optimum performance for a plant of a widely grown cultivar that is old on “replicative fading.”

3

Would this (or how should this) translate into reproduction of our own seedlings that we wish to have more copies for testing or breeding with? Are there steps to take starting with the first plant and those thereafter that we can take to avoid this? Or is this usually amplified over time by many copies being made?
Duane

4

This is essentially what I’m asking, too. Can you breed two duplicates with each other?

5

See:

AND

https://onlinelibrary.wiley.com/doi/full/10.1111/plb.12375?casa_token=qcHU7FWoqokAAAAA%3Ap4z6cdv2X0aXdwpsQH8KVC89wO81ezQ9w_aXrBcjLXyUR4WHoJUpZGxZecxttU_G1823N6ytzj5THIR3ww

6

The basic idea is that a vegetatively propagated plant inevitably wears out. The subject has been discussed since the early 19th century, at the latest. But the subject seems less than certain. For instance, I have a 12th century record from Spain of Rosa foetida bicolor being grown in Tripoli of Syria and parts of Alexandria. This variety has been propagated by cuttings and buds ever since, without apparent decline.

On the other hand, there are some good reports of garden roses that apparently degenerate in a fairly short time. This can be a decline in vigor, reduced disease resistance, fewer petals and even changes in color. These are not necessarily the result of irreversible degeneration. Careful bud selection can restore the plants to their original glory … and sometimes exceed the beginning form.

Viviand-Morel: Amateur Rose Breeding (1914)
“In a very different way, M. Dhumez was able to get from Nature more than she had ever wanted to give. Disregarding the field of selection of seedling variations, and confining himself to varieties which he had bought in the open market—some of them little known, such as Prince de Bulgarie, and others long since used by everyone, some of them for a long time past, such as Bastide rose—M. Dhumez was able, by a very sure selection, a judicious choice of fertilizers and, especially, of method of operation, to get such remarkable results that they would have been declared impossible: the size of the flowers, the absolute perfection of form and color of Prince de Bulgarie, Marquise de Mores, Agathe Nabonnand, Agathos and others, won as soon as they appeared not only the rapt astonishment of the public, but the highly-valued admiration of experts.”

This bibliography lists more cases of roses and other plants being improved by vegetative selection.
http://bulbnrose.x10.mx/KKing/VegetativeSelection.html

7

I remembered that this subject was discussed on rec.gardens.roses back in the '90s. Here’s a snippet I found today. Some of the “degradation” described could be the result of poor propagation practices, and might be repaired by careful bud selection … if anyone wants to make the effort.

Also, I added another batch of links to the Vegetative Selection biblio I linked before. These involve adventitious shoots and root sports. It is sometimes possible to recover an original type from these, as well as isolate/create new sports.
http://bulbnrose.x10.mx/KKing/VegetativeSelection.html

In article 19991205100102...@ng-ch1.aol.com,
mscha...@aol.com says…

Has anyone taken into consideration cultural and climate differences
changing roses? The Peace rose that was blooming in my parents’ yard in Georgia
when I was a child was different from the virus free Peace I bought last year
and have been been growing here in SoCal. But the roses change colors somewhat
anyway with the temperatures, seasons, and trace minerals in the soils. Even
the ultraviolet light is greater now in some areas with atmospheric
degeneration.
It’s interesting that Heirloom Roses has imported Peace from Austin in
England, because they believe the American stock has declined so. They don’t
show a picture of it in the 2000 catalog, but describe it as a “golden yellow
with a pink edge to each petal intensifying to almost red as the flower ages.”
Has anyone seen it? (“Will the real Peace please stand up.”)

Altadena Mara

What is being called genetic degradation is sporting of the
roses and the sports being propagated and over the years a
rose like Peace that does sport a lot and proven by the many
sports that have been named and sold. The original Peace we
had in 47 does hardly resemble the junk sold today. We also
had a climber that was identical in color and sorry I didn’t
take cuttings when we moved from L.A. but got a new climber
that was close but not as vigorous and died after about 10
years. The replacement this time is still growing and is
close to a real original peace but if seen side by side it
would not be considered a true peace. We have got some peace
bushes in the last few years and none are even close, and
even the foliage is not quiet the same. The blooms are a
washed out distant cousin of a true peace.

We have an original Chrysler Imperial (it came from the
original mother block) and it is deeper red then even two
other Chryslers we have that were got about 4 years after
the original one. But we see newer ones that are not the
same rich dark red of our original.

Paula, The one you sent me that Don budded from our bud
wood is now doing good in a 15 gallon pot. Should get blooms
this year that we can compare to the original Chrysler. That
old original one is still blooming good even if now 50 years
old. It appears now to be three bushes, one on Dr Huey as
gets Huey suckers and 2 more on own roots.
Bill in Alhambra Calif.
whil...@mindspring.com

9:50:14 am 12/5/1999
https://groups.google.com/g/rec.gardens.roses/c/5T6lWTNeyUQ/m/XpvePwfFyXAJ

8

Another source regarding this interesting subject: Why plant 'clones' aren't identical -- ScienceDaily

9

Though this report deals with humans, the underlying principle may well apply to plants. Therefore, two cuttings from a seedling may become epigenetically distinct, more so the older they become, and even more so when they have been exposed to different environmental histories.

In past centuries it was common knowledge that the health and vigor of a strain of wheat, or breed of horse, may be rejuvenated by a change in environment … including nourishment. I will venture to guess that mating Crimson Glory x Crimson Glory will give very different results when two specimens have been maintained in different climates, rather than one plant being self-pollinated.

Karl

The Scientist, Jul. 7, 2005
How epigenetics affects twins
In genetically identical siblings, DNA methylation and histone acetylation correlate with age and lifestyle
By Charles Q. Choi

The largest twin study on epigenetic profiles yet reveals the extent to which lifestyle and age can impact gene expression, an international research team reports in this week’s PNAS. Senior author Manel Esteller of the Spanish National Cancer Center in Madrid and colleagues found that 35% of twin pairs had significant differences in DNA methylation and histone modification profiles.

“These findings help show how environmental factors can change one’s gene expression and susceptibility to disease, by affecting epigenetics,” Esteller told The Scientist.

Esteller and colleagues in Sweden, Denmark, Spain, England, and the United States studied 80 sets of identical twins, ranging in age from 3 to 74 years. Their aim was to explore what role epigenetics plays in generating phenotypic differences between genetically identical twins.

The researchers analyzed the twins’ global DNA methylation and histone H3 and H4 acetylation in samples from lymphocytes, buccal mucosal epithelial cells, skeletal muscle biopsies, and subcutaneous fat. They quizzed participants on their health, nutritional habits, physical activities, drug treatments, and consumption of tobacco, alcohol, and drugs. They also checked their height and weight.

Statistical analysis suggested that older twin pairs were more epigenetically different than younger twins. It also revealed that twins who reported having spent less time together during their lives, or who had different medical histories, had the greatest epigenetic differences. Gene expression microarray analysis revealed that in the two twin pairs most epigenetically distinct from each other–the 3- and 50-year-olds–there were four times as many differentially expressed genes in the older pair than in the younger pair, confirming that the epigenetic differences the researchers saw in twins could lead to increased phenotypic differences.

10

Thanks for all the info. It seems that epigenetic play a larger role than previously thought!