@beckygardener
beckygardener said:So a daylily division should create an identical plant whereas a prolif produced and growing on a scape may not?
Both a daylily division and a prolif may not create a genetically identical plant.
Are the prolifs "typically" close to identical to the parent plant it was produced by?
Both will be close to identical to the parent plant the vast majority of the time.
No method of reproducing a plant is perfect. That is because the fundamental processes in the plant itself are not perfect.
Recall that when a daylily fan flowers it uses up its growing point (shoot apical meristem). It must make a replacement. In making that replacement errors can be present naturally and those errors once made will remain with the plant more or less forever. Errors occur rarely but without fail when enough cells are produced.
To make a proliferation the plant starts making a scape. As it does so it uses up its meristem which is a reproductive meristem. That is, when the plant makes a branch on the scape the meristem becomes smaller. When the plant makes a flower bud its meristem becomes smaller. At some point an accident occurs and the outside environment plus the plant's internal environment (probably mainly its plant hormones) acts to turn the reproductive meristem back into a vegetative meristem. It is possible that the number of cells in the meristem is less than the number that typically is in a normal vegetative meristem. However, the number of cells in a meristem depends on the size of the meristem and that most likely depends on the size of the fan.
The reason I mentioned the proliferations is that they are produced by the plant in an untypical way. The plant turns a reproductive meristem back into a vegetative meristem. To do that it is likely that the plant hormones are not normal. Micropropagation of a plant turns plant cells into meristems by manipulating the plant hormones. Of course when a plant makes a normal replacement meristem it has to turn normal cells into meristems. Another method of making a new meristem would require dividing an existing meristem into two. However, my understanding is that daylilies do not divide apical meristems to make axillary meristems; they turn normal cells into new axillary meristems.
Most of the genetic changes that occur over time, even in a vegetatively propagated daylily will not be readily noticeable to a gardener.
The following is one example of how to check for such changes (simplified and leaving out many checks, controls, etc.).
Assume that two clumps of a particular cultivar have been growing separately for many years. I have two clumps of 'Coyote Moon' that have been separated for about 20 years.
Divide the two clumps into single fans. Label the fans of one clump as A and those of the other clump as B.
Choose one fan from A and then a fan from B that is as close as possible in size.
Plant the labelled fans of A and B in a new location in a random order say A then B.
Choose another fan from A and a fan from B that is as close as possible in size.
Plant the labelled fans of A and B in a different new location in random order (using the toss of dice to decide which fan gets planted first).
Keep repeating the two steps above until all the fans have been planted.
Treat every plant identically by measuring the amount of water and fertilizer each is given.
Some time later come back and measure some characteristics of the plants. The person measuring the characteristic should not know which plant is A and which is B. A second person will have that information.
Statistically analyze the measurements.
Or of course as an alternative one could have the DNA extracted from one fan from clump A and from one fan of clump B and compared.
A few more details of the Easter lily example.
The researchers took samples of lily bulbs (of the same cultivar) from different growers and compared the DNA. They were not identical. The growers know that their bulbs change with time. Below is a quote,
"Bulb producers are aware that mutations occur within their stock and undesirable variation builds up over time. To address this problem, periodically growers introduce a new line or somaclonal selection of ‘Nellie White’ into production. About every ten years, each bulb grower starts a new round of selections for the next new line. They go through the production fields at regular intervals and mark individual plants possessing desirable traits. In the beginning of the season over 2,000 plants may be marked, but by the end of the season typically 200 remain that made it through selection for important traits. Plants in the running at the end of the first season are propagated and observed in subsequent years in both field and greenhouse forcing tests. After a few years the best selection (tracing back to one bulb in the original year of selection) is mass propagated and then put into production."
