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Jan 12, 2014 8:17 AM CST
Thread OP
Name: Tina
Where the desert meets the sea (Zone 9b)
Container Gardener Salvias Dog Lover Birds Enjoys or suffers hot summers Million Pollinator Garden Challenge
Garden Ideas: Level 2
I know that some Tets spontaneously revert back to Dips after conversion, but does anyone know if there is an inducible way to "convert-back" a multi-generation Tet offspring (bred to encourage fast and valued mutations in the Tet line) as a Dip?

For example, Edith Sliger is a sixth-generation Tet hybridized in 2000. In the intervening generations after its Tet progenitors were used, no tet-converted dips were recorded in its lineage. Is it possible there is a way that such a Tet, with its now very different genetic make-up from any of its unrecorded dip ancestors, be re-converted back to dip for use with other cultivars still available in dip form?
Do not seek to follow in the footsteps of old; seek what those of old sought. — Basho

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Last edited by chalyse Jan 12, 2014 8:23 AM Icon for preview
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Jan 12, 2014 8:23 AM CST
Name: Michele
Cantonment, FL zone 8b
Seller of Garden Stuff Region: United States of America I was one of the first 300 contributors to the plant database! Dragonflies Pollen collector Garden Ideas: Level 2
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No a Tet cannot be converted to a dip. If it can I have never heard of it and I have asked others this same question just out of curiosity with the answer of no.
www.pensacoladaylilyclub.com
Last edited by tink3472 Jan 12, 2014 8:31 AM Icon for preview
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Jan 12, 2014 8:29 AM CST
Thread OP
Name: Tina
Where the desert meets the sea (Zone 9b)
Container Gardener Salvias Dog Lover Birds Enjoys or suffers hot summers Million Pollinator Garden Challenge
Garden Ideas: Level 2
Shoot. But, okay then, I guess I'll just have to keep tweaking my google terms to hunt down hints for ways to jostle Tets into spontaneously shaking out those extra chromosomes. Rolling my eyes. perhaps it has been done with some other converted plants than daylilies ...

Edit Update: Ooh, Ooh! "A process of conversion of tetraploid cells to diploid cells may exist (2008) ..." @ science direct ... already on the scent... :D

And...yes! in rockcress, a relative of cabbage and mustard (2010) @ http://www.readcube.com/articl... ... sounds more advanced-science than dip to tet conversion, but it may be that they are looking into ways and means ... as there are hints that it may be helpful science for investigating how to work with cancer tumors.

also http://www.nature.com/nature/j... for pictures

yay!
Do not seek to follow in the footsteps of old; seek what those of old sought. — Basho

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Last edited by chalyse Jan 12, 2014 8:53 AM Icon for preview
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Jan 12, 2014 11:04 AM CST
Name: Maurice
Grey Highlands, Ontario (Zone 5a)
There are ways to convert tetraploids to diploids.

One way is to tissue culture either the pollen or the ovule (gametes) since they are already 'diploid' in a tetraploid. In other words a tetraploid has 44 chromosomes and the gametes have 22 chromosomes.

Producing diploids from tetraploids is not extremely unusual - look for research describing the production of haploids from diploids. In practice a very large percentage of all plant species have in the distant past naturally doubled all their chromosomes one or more times. The end result is that many diploid species are ancient tetraploids that now act like perfect diploids (most of the time). So creating a haploid (half of the normal number of chromosomes) can effectively create a diploid form.

There is also another way that researchers can produce 'diploids' from tetraploids and that is by pollinating the tetraploid with pollen from a completely different species. The pollen must be basically almost completely incompatible (you do not want to produce hybrids) and it acts to stimulate the growth of the ovule but the pollen chromosomes are either destroyed or otherwise lost from the developing embryo. Again look for research on creating haploids by using intergeneric crosses or incompatible pollen, etc.

Below are two starting points - there will be many research papers for many different species but not that I know of specifically for tissue culture of daylily pollen.

Barley haploids from intergeneric crosses with maize (Zea mays L.) http://wheat.pw.usda.gov/ggpag...

Anther and Pollen Culture (Production of Haploid Plants) http://www.eplantscience.com/i...

You might try pollinating the tetraploid daylily with Lilium pollen or with the pollen from other members of the Hemerocallidoideae (older - Hemerocallidaceae), such as Dianella or Stypandra or Simethis or perhaps Phormium, etc.

However, when a tetraploid is converted to a diploid any unusual phenotypes that are based on four copies of each gene may be lost when only two copies are present. Daylilies are somewhat unusual in that hybridizers have continued to select in both the diploid and tetraploid gene pools. The tetraploids have developed some phenotypes that are not obviously present in the diploids. Whether there are genotypes present in the tetraploids that do not have corresponding genotypes in the diploids (other than those based on four alleles versus two alleles - if any) is not known.

Any diploid produced from a tetraploid will have a random sample of two of the four chromosomes for each of the 11 sets.

When looking for new mutations it is always best to do so in diploids rather than tetraploids (far easier in diploids). That is also the case for selecting for new phenotypes (genetically based).
Maurice
Last edited by admmad Jan 12, 2014 11:23 AM Icon for preview
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Jan 12, 2014 12:10 PM CST
Name: Mike
Hazel Crest, IL (Zone 5b)
"Have no patience for bare ground"
Admmad, there is so much going on here. Thanks for your deep insight into this subject. To me it would make more sense to convert the dips in question and then cross them. It gives the hybridizer a greater potential with the double chromosomes on both sides.
robinseeds.com
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Jan 12, 2014 3:05 PM CST
Thread OP
Name: Tina
Where the desert meets the sea (Zone 9b)
Container Gardener Salvias Dog Lover Birds Enjoys or suffers hot summers Million Pollinator Garden Challenge
Garden Ideas: Level 2
Awesome development and such helpful info put in more layperson terms (thanks!) on the haploid information, Maurice, thanks! And, right, Mike, the idea is that after Tets are converted and crossed further for their mutation value (for example, there are at least six generations behind the Tet cultivar Edith Sliger) you could then get back to the diploid form to cross Dip Edith Sliger further with the dip lines (thus possibly increasing the genetic mix of the dip lines). Great to have more about this to read during the winter! Thumbs up
Do not seek to follow in the footsteps of old; seek what those of old sought. — Basho

Daylilies that thrive? click here! Thumbs up
Last edited by chalyse Jan 12, 2014 3:08 PM Icon for preview
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Jan 12, 2014 3:38 PM CST
Name: Maurice
Grey Highlands, Ontario (Zone 5a)
There are other possibilities for getting diploids from tetraploids (or haploids from diploids more generally).

If a tetraploid plant is irradiated (with x-rays, ultraviolet light, etc) at an appropriate dose at the appropriate time when the pollen is developing then the chromosomes can be effectively 'destroyed' but the pollen maintains its viability. If that irradiated pollen is used to pollinate a tetraploid then it is possible for some of the ovules to develop into diploids (generally scientifically into haploids).

This article provides an introduction to various methods of producing haploids.
http://www.intechopen.com/book...
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Jan 12, 2014 8:10 PM CST
Thread OP
Name: Tina
Where the desert meets the sea (Zone 9b)
Container Gardener Salvias Dog Lover Birds Enjoys or suffers hot summers Million Pollinator Garden Challenge
Garden Ideas: Level 2
Awwwwwesome Hurray! spot on! Thanks for that very cool info!
Do not seek to follow in the footsteps of old; seek what those of old sought. — Basho

Daylilies that thrive? click here! Thumbs up
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Jan 16, 2014 3:40 PM CST
Name: Fred Manning
Lillian Alabama

Charter ATP Member Region: Gulf Coast I was one of the first 300 contributors to the plant database! Amaryllis Region: United States of America Garden Ideas: Level 2
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I do not understand why we would want to go from tet to dip when the tets came from dips in the first place. Here's an article on the subject.

Plants with more chromosomes tend to have more substance than their diploid cousins. Tetraploid daylilies have larger and thicker leaves and flowers, stronger flower scapes, more intense coloration and increased vigor. Because of the difference in the number of chromosomes, diploid and tetraploid daylilies cannot be crossbred to produce new types. While most of the major daylily awards have gone to diploid selections, much of the excitement among daylily enthusiasts in the last few years has been about tets.

Artificial manipulation of chromosome numbers began in 1937 when it was discovered that a potent alkaloid drug called colchicine, extracted from the bulbs of the autumn crocus, caused chromosome doubling in a wide array of plants. By the late 1940's this discovery was being used as a topic of research projects for several students pursuing advanced degrees in plant breeding. Either established plants or seedlings can be transformed to tetraploids using colchicine.

The first tetraploid daylilies bloomed in California in 1947, but they were a far cry from what breeders have been able to develop in the subsequent decades. The first tetraploid daylily to win the Stout Award, the highest award given by the American Hemerocallis Society, was a yellow flowered cultivar called ‘Mary Todd’ that won in 1978. Since 1996 all of the Stout Award winners have been tetraploids.
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Jan 16, 2014 4:38 PM CST
Name: Betty
Bakersfield, CA
Charter ATP Member I was one of the first 300 contributors to the plant database! Birds The WITWIT Badge Garden Ideas: Level 1 Roses
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Thank you, Fred -- that was very informative and answered a couple of questions I've had for a while now. However, there is one thing I would like to note -- the diploid NORTH WIND DANCER won the Stout Medal in 2011, but I suspect this information was written before that had happened.

Edit: YIKES -- And how could I forget that the diploid HEAVENLY ANGEL ICE recently won the Stout Medal for 2013? Getting old here...
Betty
Last edited by Betja Jan 16, 2014 5:02 PM Icon for preview
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Jan 16, 2014 11:49 PM CST
Thread OP
Name: Tina
Where the desert meets the sea (Zone 9b)
Container Gardener Salvias Dog Lover Birds Enjoys or suffers hot summers Million Pollinator Garden Challenge
Garden Ideas: Level 2
Yes, tets came from dips, and have moved forward as tets-only over many generations. Because they have more chromosomes it is easier for them to mutate faster. So, to bring some of those more highly mutated genes (newer patterns, edges, etc) into the dip line, it might be desirable or useful to revert some tets and bump up the dips a bit. I've only watched the growth and performance of 150 cultivars, almost equally divided between dip and tet, but I haven't personally really been struck by any bigger-stronger-healthier aspect that everyone says is there (and for those where I have the tet and dip of the same cultivar side by side - its even worse; the tet versions have been smaller, less appealing, way less healthy over the long haul) ... I know that maybe its just my 150 cultivars ... but the only characteristic that has struck me is that tets seem to have a bit of edge on somewhat deeper color concentration and more variety in patterns.

And, I've noticed in just my small number of daylilies that many cultivars that are known as dips are really tets now. For example, I was unable to get a dip cross from Dixie Land Band its first summer, so I tried some tet crosses with it and got tons of seedlings. Nowhere is it listed as a tet, so it must have been quietly converted and may now be the predominant form that is being sold. It is not the only "dip" cultivar that I've found to be a "closet tet," and since no one keeps track of tet conversions, from now on I am going to routinely cross all unsuccessful "dips" with tets.

Ultimately I prefer to keep and work with dips, so I think that 1) it would be nice to revert some of the "closet tet" cultivars converted back to their original dip state (made available as both tet and dip) and 2) it would be great to have some of the more highly mutated tet genes brought back to dips to see if they might pop up the colors and patterns of the dip lines any. Thumbs up
Do not seek to follow in the footsteps of old; seek what those of old sought. — Basho

Daylilies that thrive? click here! Thumbs up
Last edited by chalyse Jan 17, 2014 3:44 AM Icon for preview
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Jan 17, 2014 6:23 AM CST
Name: Fred Manning
Lillian Alabama

Charter ATP Member Region: Gulf Coast I was one of the first 300 contributors to the plant database! Amaryllis Region: United States of America Garden Ideas: Level 2
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Betty that is an old article.

There have been several daylilies that have had tet and dip pollen and have produced both kinds of seedlings, some of these may have been treated at one time and were not 100% tet or a flaw in the plant. I have been working with dips since the early 90s and for myself very happy about where dips are today and believe they are still the future of tet daylilies.
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Jan 17, 2014 8:49 AM CST
Name: Maurice
Grey Highlands, Ontario (Zone 5a)
chalyse said:Yes, tets came from dips, and have moved forward as tets-only over many generations. Because they have more chromosomes it is easier for them to mutate faster. So, to bring some of those more highly mutated genes (newer patterns, edges, etc) into the dip line, it might be desirable or useful to revert some tets and bump up the dips a bit.


Tetraploids have twice as many chromosomes as diploids and so they do have approximately twice as much DNA that can mutate. But it is much harder to find or see (work with) those mutations in a tetraploid than in a diploid. As a simple example, consider a simple recessive mutation (the majority of new mutations are recessive). In a diploid the mutation will occur and the individual plant that is carrying the mutation will be heterozygous (N = normal and n = mutation) Nn. If we have two individuals carrying the new mutation (for example the plant was self-pollinated) and we cross them then Nn x Nn will produce approximately 3 normal to 1 visibly mutant offspring.

When a new mutation first occurs in a tetraploid then that plant will be NNNn. If we self-pollinate it then the best we can hope for is that some of the offspring will be NNnn and there will not be any visibly mutant offspring. If we somehow have two individuals that are NNnn and we cross them then approximately 1 out of 36 of the offspring of that cross will be nnnn and visibly mutant. Tetraploids genetics can even be much worse - individuals that are NNnn may produce only Nn pollen or ovules so that the cross NNnn x NNnn produces only NNnn offspring (called fixed heterozygosity). There are other complications in tetraploid genetics that affect the numbers of genotypes produced by crosses.

Although I strongly consider that there is no characteristic (phenotype) present in tetraploids that is not or cannot be found in diploids the actual extent of some characteristics in diploids may not be similar to that in tetraploids. Tetraploids on average have cells that are larger in volume than diploids. That size difference and its effect on characteristics may not be directly transferable to diploids. For example, it is possible that larger cells allow larger ruffles and wider and darker (more intensely coloured) picotees in tetraploids.

In the past professional plant breeders working with single gene mutations in tetraploid plant species have preferred to work in the diploid versions and then to double the diploid version to transfer the new mutation to the desired tetraploid version.

Tetraploid daylilies have possibly advanced more than diploids because at some point far more hybridizers started working with tetraploids and made far more crosses than were made with diploids.

Unfortunately the ploidy listed in the AHS registration database cannot be considered to be error-free. Researchers checked the ploidy of 94 cultivars and 6 were incorrect - that is approximately one incorrect ploidy for every 15 registered cultivars. The incorrect ploidies were both diploid and tetraploid and two of the six were triploids registered as diploids.
Maurice
Last edited by admmad Jan 17, 2014 10:55 AM Icon for preview
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Jan 17, 2014 10:28 AM CST
Name: Betty
Bakersfield, CA
Charter ATP Member I was one of the first 300 contributors to the plant database! Birds The WITWIT Badge Garden Ideas: Level 1 Roses
Irises Daylilies Cat Lover Region: California Region: United States of America
One reason I really prefer the tets is the strength and thickness of the scapes. I usually have to stake my dip scapes here in Bakersfield, but almost never with the tets.
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Jan 18, 2014 7:49 AM CST
Name: Glen Ingram
Macleay Is, Qld, Australia (Zone 12a)
(Lee Reinke X Rose F Kennedy) X Unk
Amaryllis Hybridizer Canning and food preservation Lilies Native Plants and Wildflowers Orchids
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Maurice, you mentioned plural triploids - so there are other interesting triploids other than Kwanzo?
The problem is that when you are young your life it is ruined by your parents. When you are older it is ruined by your children.
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Jan 18, 2014 8:40 AM CST
Name: Maurice
Grey Highlands, Ontario (Zone 5a)
Yes there are triploid daylilies other than Kwanso and Europa and several other fulva types.

The researchers determined that 'Celtic Sunrise' and 'Forbidden City' are triploids.

Many years ago Arisumi also determined that there were other registered triploids. He found that 'Garnet Robe' is triploid.

Chinese researchers have indicated that 'Baltimore Oriole' is a triploid. In other Chinese research 8% of AHS registered daylilies were identified as triploids by counting chromosomes. That number may be a little high as there is always the possibility that a plant that is being grown as cultivar "X" has been mislabelled somewhere in the production system and is actually a similar but different cultivar with a different ploidy than the true "X". That later research was unable to confirm the triploidy of 'Baltimore Oriole' indicating that it is tetraploid but then indicated that Chicago Apache, Spacecoast Gator Eye, Spacecoast Starburst, Crystal Pinot, Daring Deception, Strawberry Fields Forever, and Moonlit Masquerade are triploids.

There is a current hybridizer and researchers interested in producing triploid daylilies - 'VT Spirit' is their triploid introduction.

It is possible to produce triploid daylilies by simply crossing diploids with tetraploids. That is what Arisumi did. It does require perserverance. He used two techniques. A simple one of crossing them and then planting any mature developed seeds and a more complicated one of opening immature seeds, removing the embryo and growing it in a nutrient medium (called embryo rescue or culture). Both worked and more or less equally. He made 1,607 pollinations. From those he harvested 1,218 seeds. Only 155 of those seeds appeared normal - firm and solid when squeezed. He planted 100 of those seeds normally and 23 germinated to produce 17 triploid plantlets. The remaining 55 seeds were used in embryo culture and produced 12 triploid seedlings. In total there were 17% triploids from normal planting and 21.8% from embryo rescue - about the same success rate.

Although triploids are considered to be sterile most are not 100.0% sterile if enough pollinations are tried (hundreds to thousands). In daylilies triploids tend to be slightly more fertile in crosses with tetraploids but they can also have low fertility with diploids. By making large numbers of pollinations between triploids and diploids it should be possible to produce some viable seeds - probably producing some diploid seedlings. Researchers call this a triploid bridge because it can move genetic characteristics from diploid to tetraploid forms of species in natural conditions.
Maurice
Last edited by admmad Jan 18, 2014 10:38 AM Icon for preview
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Jan 18, 2014 12:16 PM CST
Thread OP
Name: Tina
Where the desert meets the sea (Zone 9b)
Container Gardener Salvias Dog Lover Birds Enjoys or suffers hot summers Million Pollinator Garden Challenge
Garden Ideas: Level 2
Triploids have always intrigued me ... do you know if the low fertility is just on the pollen side, and if the cross is successful, whether the pods are set consistently (Tet pod vs. Dip pod)? Thanks so much for the list of triploids - it prompted me to wonder if there might be some additional ones in the ATP database, and indeed there are:

Adel Ga's Southern Hospitality
Crazy Miss Daisy
Desperado Love
Frankly Fabulous
Judge Judy
[EDIT] Fred Manning, the hybridizer, notes this cultivar's listing is in error (not a Triploid) and will update the database -- Lillian's Little Joe
Sahara Splendor
Shout from the Mountaintops
Sweet Tranquility
Swiss Legacy

I'll try to add the links later (back to bed with a cold...). I think I will have to get what ones I can and give this natural bridge a try! And, I'm going to ask the obvious-but-I'm-not-feeling-quite-sure question ... I assume that Trips have three sets of chromosomes, with intermediate sized/shaped pollen, and in hybridizing over the bridge they either pick up an additional set of chromosomes from the Tet parent or lose the extra one via the Dip cross?
Do not seek to follow in the footsteps of old; seek what those of old sought. — Basho

Daylilies that thrive? click here! Thumbs up
Last edited by chalyse Jan 19, 2014 3:02 PM Icon for preview
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Jan 18, 2014 3:23 PM CST
Name: Maurice
Grey Highlands, Ontario (Zone 5a)
The low fertility of triploids is both on the pollen and on the pod side usually. But every triploid cultivar is likely to be different. When one crosses a diploid with a tetraploid in either direction or a triploid with a diploid in either direction or a tetraploid with a triploid in either direction pods will be set at the typical percentage for the pod/pollen parent combination. As an example, If diploid 'Pardon Me' pollinated with diploid 'Barbara Mitchell' pollen sets a pod 8 out of 10 times (80%) then diploid Pardon Me pollinated with tetraploid Barbara Mitchell will set a pod 8 out of 10 times. Even if the two parents have different ploidies the crosses 'take' and set a pod relatively normally. The problems rear their heads slightly later - within seven to ten days most of the pods will abort. A few will linger on and appear to develop but abort later and a very few will manage to develop for five weeks or more. Most of those will show wrinkled collapsed sections or compartments. When opened they are likely to have only one or two mature looking seeds at best, most will not have any good seeds. Triploids typically produce a lower proportion of viable pollen/ovules than diploids or tetraploids but should be consistent in the same growing conditions (temperature being most important).

Yes, specific crosses that manage to keep their pods developing for the longest are likely to be consistent. What Arisumi did was look to see which crosses kept their pods for more than a week and then concentrated on repeating those crosses.

Triploids do have three sets of chromosomes. Their pollen will be many different sizes because each pollen grain is likely to have a different number of the 33 chromosomes. A diploid with 22 chromosomes has a working method of producing pollen with exactly 11 chromosomes (one from each of the 11 pairs). A tetraploid has a partially working method of producing pollen with 22 chromosomes (a pair for each of the 11 quadruples). Pollen from tetraploids may not be exactly 22 chromosomes due to errors in pairing during its production. But triploids have an extremely error prone pollen production. Triploid pollen can have anything from 11 to 22 chromosomes. Each triploid cultivar may have a different average number of chromosomes in its pollen and a different range of chromosome numbers.

When a triploid is crossed with a diploid successful offspring will be produced when the triploid's pollen (or ovule) has exactly 11 chromosomes to produce a diploid or if by chance it has exactly 22 chromosomes to produce another triploid.

When a triploid is crossed with a tetraploid successful offspring will be produced when the triploid's pollen (or ovule) has exactly 22 chromosomes to produce a tetraploid or if it has exaclty 11 chromosomes to produce another triploid.

Some triploids may be almost completely sterile. Other triploids might have reasonable fertility with tetraploids but be almost completely sterile with diploids or vice versa. 'Garnet Robe' was apparently reasonably fertile with tetraploids but sterile with diploids. When crossed with tetraploids there were four pods successfully set out of ten pollinated flowers and nine seedlings were produced (8 tetraploids and 1 triploid) in total. There are seven diploid offspring registered in the AHS database as having Garnet Robe as a parent.

Temperature at the time that pollen (or ovule or more properly gamete) is produced has an effect on how many errors occur and therefore the number of chromosomes in the pollen grains. Daylily pollen is actually produced many weeks before the flower opens (possibly months before). So whether diploid-triploid crosses produce viable seedlings may depend on when and where the crosses are made - first bloom period, rebloom period, in the garden, in the house, in a greenhouse, etc.
Maurice
Last edited by admmad Jan 18, 2014 4:57 PM Icon for preview
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Jan 18, 2014 3:48 PM CST
Name: Glen Ingram
Macleay Is, Qld, Australia (Zone 12a)
(Lee Reinke X Rose F Kennedy) X Unk
Amaryllis Hybridizer Canning and food preservation Lilies Native Plants and Wildflowers Orchids
Plant Lover: Loves 'em all! Pollen collector Lover of wildlife (Raccoon badge) Plays in the sandbox Sedums Seed Starter
Excellent information, Maurice. I am building up a copy book of your posts.
The problem is that when you are young your life it is ruined by your parents. When you are older it is ruined by your children.
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Jan 18, 2014 10:03 PM CST
Thread OP
Name: Tina
Where the desert meets the sea (Zone 9b)
Container Gardener Salvias Dog Lover Birds Enjoys or suffers hot summers Million Pollinator Garden Challenge
Garden Ideas: Level 2
I agree and am so glad for the forum search function to reference back here ... this process has already identified three triploids that are just what i'm hoping to work with in bridging, and are available at $5 each from vendors i know and trust. most appreciative of the list and hybridizing info!

the layers of scientific knowledge here are so very helpful, and the conversation making the steps toward understanding it all, and using that information to move forward, are superb.
Do not seek to follow in the footsteps of old; seek what those of old sought. — Basho

Daylilies that thrive? click here! Thumbs up

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