AusBonsai

At my place I have a trident maple as a garden plant and every year there are hundreds of seedlings that grow as a result of the seeds produced. The professional weeder does her best to remove all the seedlings before they get too big, but the odd one that she misses grows a bit and I go around and just cut them down, So that is the basis.
Some grow with green leaves, some with red leaves and a few with orange leaves and I can't work out why this is so. Any ideas?

I know that Japanese Maple seedlings hold virtually no resemblance to the parent plant. Leaf shape, size and colour can all be wildly different to the parent plant. I assume this is the same thing occurring with trident maple.

Occasionally a particularly nice seedling occurs and will become an official cultivar, but that might be 1 in a million. I know that it takes up to 7 years for a ‘true’ Japanese maple leaf to occur on a seed grown plant, in that it might have wonderful colour for a couple of years, but then can become quite plain later down the track.

I don’t fully understand the genetics behind it, but yeah, maple seedlings vary wildly from the parent plant.

Watto wrote: ↑September 15th, 2019, 3:30 pm At my place I have a trident maple as a garden plant and every year there are hundreds of seedlings that grow as a result of the seeds produced. The professional weeder does her best to remove all the seedlings before they get too big, but the odd one that she misses grows a bit and I go around and just cut them down, So that is the basis.
Some grow with green leaves, some with red leaves and a few with orange leaves and I can't work out why this is so. Any ideas?

Acer Palmatum has a fluid gene expression mechanism that enables it to take advantage of whatever microclimate they find themselves growing in. Forest trees are generally red to absorb more UV where they grow as an undercanopy tree or in steep ravines and valleys where they receive limited light.
Trees found in open spaces are generally green forms with more panel like leaves.
Having a fluid set allows the sapling to adapt to the peak condition for its environment although there are adult trees that also do this most become set to a particular gene.
Some trees especially cultivars have been bred to supress all other gene types and hence display a fairly consistent pattern of colour and texture in their foliage

None of the maples we grow are direct descendants of the original Acer. All are hybrids of hybrids of hybrids of.... And hence they all have different characteristics. Watto, if you wanted to make a forest with your seedlings, you'd be in the ideal position to choose those that most resemble each other from the seedlings that come up in your yard. Lucky you!

Lisa

LLK wrote: ↑September 15th, 2019, 6:35 pm None of the maples we grow are direct descendants of the original Acer. All are hybrids of hybrids of hybrids of.... And hence they all have different characteristics. Watto, if you wanted to make a forest with your seedlings, you'd be in the ideal position to choose those that most resemble each other from the seedlings that come up in your yard. Lucky you!

Lisa

I have already noted the maples in my 15 tree forest are different in leaf. I see this as good news as it means I can add in further trees without issue, since display would ideally be winter.

If you want to display in leaf then yes, having identical plants would be ideal.

Thanks GamaUji, that’s very interesting indeed!

Watto's post refers to Trident maple - Acer buergerianum.
Trident maples are generally much like the original species. As a larger tree it has not been bred and selected by gardeners for centuries so they are generally quite stable when grown from seed. However, in all species there is some tendency to variations, presumably as a backup for when conditions change.There are now some selected varieties with different characteristics but those are not common. There are also a couple of subspecies like Taiwan maple. Sub species tend to evolve when a population is isolated - like on an island - for a long time so the tridents on Taiwan have evolved different characteristics from their mainland relatives and now has thicker, leathery leaves that don't have the red new shoots and flowers profusely from a young age.

I have also grown occasional trident seedlings that exhibit green new growth though the vast majority have the red new shoots in spring. After a few weeks the red leaves change to green and it can be hard to tell the difference through summer.
I kept one green new leaf type for a number of years and noted that it also had some other characteristics different to the usual 'red leaf' type. It produced a massive nebari without any help from me. That's really why I kept it but it also refused to ramify well. New shoots were always coarse and did not produce side shoots often, even when pruned or pinched. Lower branches were also much weaker than upper branches so it needed better management to keep the low branches healthy. Eventually I got frustrated about poor ramification and passed it on to someone else.
I'm not sure whether these characteristics are common to any green leaf types or if that combination of characteristics was peculiar to that one seedling.

My take on your variable seedlings is just normal seedling variation.

Just look at humans for an example of genetic variability produced via sexual reproduction. Some children may look very similar to one parent or the other, some children don't look like either parent.

I must say that it is enjoyable to log on to see if anybody has posted some cool pics today and end up reading posts from various members about gene expression and speciation. Speaks to the knowledge of the membership, I reckon.
Thanks

Some good answers above but it may be to do with light/sun exposure. The red pigment will offer young leaves some protection from severe light exposure until the leaves harden off. Once hardened off they will begin to turn green as they are less likely to desiccate in the hot sun and can take full photosynthetic advantage.

Thank you all the Professor Julius Sumner Miller type people who provided info on this matter.
I might do some experiments on the seed over the coming years. Thanks again.

Watto wrote: ↑September 16th, 2019, 6:26 am Thank you all the Professor Julius Sumner Miller type people who provided info on this matter...

It’s funny you say this because when I saw the heading for this thread my initial knee jerk reaction was
“... watch, atmospheric pressure does the work!”

Advertising genius from Cadbury.

I was at the National Bonsai & Penjing Collection yesterday and noted that the two trident maple groups their both had trees with green and reddish leaves.
Very interesting.

^^^Not this dramatically, but sunlight exposure can also darken the outer leaves, while inner ones remain a bright green, especially on Japanese Maple

My older trident group also had a couple of green leaf tridents in it. They only show up for a couple of weeks then all leaves end up the same through summer. Eventually I got sick of the dramatic difference, even just for a couple of weeks, so I replaced those trees.
Sun may make some difference but this is definitely a genetic difference in the seedlings.