Found two sets of twins yesterday

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david zlesak
Posts: 461
Joined: Tue Nov 26, 2013 12:27 pm

Re: Found two sets of twins yesterday

Post: # 73074Post david zlesak
Mon Jun 07, 2021 11:11 pm

Hi Karl,

Unfortunately, I lost the plant.... Both 'Dorcas' and it died in a bad winter... I should have backed it up sooner and kept a plant going in a pot. The plant was still relative young before it died and I don't think I looked at its pollen in time to see how well it stained and I don't remember hips forming on it for the year or so I had it. Right now some of the dihaploids I have are two from Rise 'N Shine. One is fertile and the other isn't. The fertile one shows a lot of symptoms unfortunately from the seed transmitted virus that is in 'Rise 'N Shine' and doesn't hold it back like RNS and most of the other roses in the marketplace that are positive for it... This is one of those viruses that people don't seem to be too worried about in the NCPN-Roses. There is a yellow single very fertile dihaploid out of High Voltage I should focus on using in crosses this year. Over recent years I've just collected the op hips from it. I suspect it is self compatible from all the hips it makes and how relatively uniform the seedlings are. There's a nice bright white bushy dihaploid out of Cloud 10, but unfortunately it doesn't seem female fertile or make too much pollen... From my potato research days we would try to raise as many dihaploids as we could to find those with enough vigor and fertility to use to cross with diploid species potatoes. Those dihaploid species hybrids were crossed with tetraploid potatoes to get tetraploid offspring. Typically only unreduced gametes would work in those crosses as potatoes have a complex system in place generally called a triploid block.

Another great way to generate diploids is to save lots of op seed from triploids and find the diploids that also hopefully have some fertility. I have a 'Nearly Wild' diploid seedling that is single and pink like NW and it sets a limited number of hips. There are a number of diploid cultivars on the market now I think from people using a lot of triploids in crosses with each other over time. Oso Easy Lemon Zest, Oso Easy Mango Salsa, Oso Easy Cherry Pie, Pinktopia, most of the Drifts, etc. are great examples. Some have some fertility to work with and move genetics forward. Interestingly, many of these diploids with diverse backgrounds produce unreduced gametes. That's probably increases their fertility and overcomes some of the erratic pairing and segregation issues of some chromosomes depending on how the gametes are generated. One diploid with a very diverse background of ancestors of various ploidies that seems to have a high rate of unreduced gametes and gives higher ploidy seedlings routinely when I raise op hips is the Kordes rose Lupo.
Last edited by david zlesak on Tue Jun 08, 2021 11:39 am, edited 2 times in total.

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Location: Austria

Re: Found two sets of twins yesterday

Post: # 73076Post Giessen
Tue Jun 08, 2021 10:03 am

david zlesak wrote:
Mon Jun 07, 2021 11:03 am
Hi Giessen,

Not necessarily. It just has a subset of the genes of mom, so depending on what it inherited it may look like mom or a bit different. For instance, I had a diploid small twin out of the Buck rose 'Dorcas' and it was a soft yellow. 'Dorcas' must have some genes for yellow in it that are recessive and/or masked some by the pink anthocyanin pigment. So, without the anthocyanin being produced (likely didn't get those genes that allow for its production) and maybe not getting a gene that suppresses yellow pigments from being produced, it was a soft yellow. Haploids like this are a fun way to sometimes unmask and directly see some of the recessives a parent may possess and be transmitting in some of its gametes.
Thanks David, very nice example.
My probable synergid-diploid comes from ‘Claus Dalby’, it is a white rose with a shade of diluted pink in the middle of the bloom, so the seedling has a light pink color. It is also fragrant, so is the mother rose.

Karl K
Posts: 1394
Joined: Sat Jun 02, 2012 4:49 pm

Re: Found two sets of twins yesterday

Post: # 73077Post Karl K
Thu Jun 10, 2021 1:38 pm

david zlesak wrote:
Mon Jun 07, 2021 11:11 pm
Unfortunately, I lost the plant.... Both 'Dorcas' and it died in a bad winter.. unreduced gametes and gives higher ploidy seedlings routinely when I raise op hips is the Kordes rose Lupo.
Winter can be cruel.

This is all a very interesting and puzzling subject. Years ago, nearly 20, I was reading about the weirdness of some Rubus hybrids. In one case, a diploid blackberry and a diploid raspberry could cross, but never (apparently) gave diploid offspring: only some triploids and an occasional tetraploid. But then I read, somewhere else, about a researcher who took the time to examine the ovaries and anthers of the species. There were not enough unreduced gametes to account for the polyploid hybrids. This suggests that some doubling was going on. But I can't insist on this without the reference.

Going through my notes, I did find that it was Percy Wright (1964) who suggested breeding down from the tetraploid yellows to the diploids.
Why does someone not undertake to put pollen of 'Persian Yellow' (R. foetida persiana) on one of the nearest-to-yellow teas? The hybrid so produced should make a proportion of haploid pollen cells. These, fertilizing the teas again, should create a new race of roses in which it should be somewhat easier to intensify the yellow color than in our existing hybrid teas. Also, it should be easier to avoid inheriting the gene or genes for susceptibility to blackspot which come down from 'Persian Yellow.'
I thought another route might be through some of the Dwarf Polyanthas and Hybrid Musks allegedly descended from Rosa foetida, such as 'Mevr. Nathalie Nypels', 'Helen Leenders;', 'Aschenbrodel' and 'Tip-Top'. But that might not work because the brilliant color of Foetida requires the special forms of carotenes that it carries, as well as the more stubborn refusal to burn off the carotenes as perfumes.

Among my notes was one regarding dihaploids and their offspring that Henry Kuska posted back in 2002. And I found a follow-up from 2003. ... s2002.html ... d2003.html

All this reminded me of some odd results that Burdick (1951) found in the progeny of doubled haploid tomatoes. In one line, the original haploid had colorless skin. The doubled plants grown from callus tissue also had colorless skin. But two of the eight plants gave some plants with Yellow skinned fruit. Spooky! ... o1951.html

I already had Gluschenko's report on his puzzling "vegetative hybrids" from tomatoes differing in color and form. ... ko_06.html
This all put me in mind of transposons. And so I did a quick search and came up with this:
The impact of transposable elements on tomato diversity (2020) by Dominquez et al.
Tomatoes come in a multitude of shapes and flavors despite a narrow genetic pool. Here, we leverage whole-genome resequencing data available for 602 cultivated and wild accessions to determine the contribution of transposable elements (TEs) to tomato diversity. We identify 6,906 TE insertions polymorphisms (TIPs), which result from the mobilization of 337 distinct TE families. Most TIPs are low frequency variants and TIPs are disproportionately located within or adjacent to genes involved in environmental responses. In addition, genic TE insertions tend to have strong transcriptional effects and they can notably lead to the generation of multiple transcript isoforms. Using genome-wide association studies (GWAS), we identify at least 40 TIPs robustly associated with extreme variation in major agronomic traits or secondary metabolites and in most cases, no SNP tags the TE insertion allele. Collectively, these findings highlight the unique role of TE mobilization in tomato diversification, with important implications for breeding. ... s2020.html
Given the number of these critters in a single species, and their varied roles, I'm thinking that McClintock was right in calling them "controlling elements". They may be easier to find when they are involved in variegations, but their involvement in environmental responses seems to be very relevant in the evolution of adaptations.

And furthermore, what has already been observed in the behavior and inheritance of variegations may offer an explanation for some aspects of vegetative selection.

For example, Louis de Vilmorin found, though much experiment, that varieties with striped flowers are more likely to come from other varieties with white or light flowers. Solid colored types never (in his experience) gave rise to striped varieties. ... n1865.html

Modern research that I've found has confirmed that at least some of his striped varieties (e.g. striped snapdragon) involve transposons. And thanks to Prof. deVries, we know that the expression of striping in the striped snapdragon can be selected in one direction to give mostly plants with solid red flowers, and in the other to give yellow flowers with only a few small, thin red stripes. ... riped.html

Correns (the first of the Mendel Three who actually mentioned Mendel) found that when he crossed a white Four o'clock (Mirabilis jalapa) with a yellow, the offspring were yellow with red stripes. On closer inspection, he found that a very few of the white flowered type had small, thin red stripes. Of course, he had no way of explaining his results.

I think it is interesting to note that Burbank once found a Golden Poppy (Eschscholtzia californica) with a thin red line running through one petal of each flower. From this plant he raise around a hundred seedlings that were all normal ... except for 4 or 5 with the red stripe. One of these became the parent of the crimson race of California poppies. ... rleys.html

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