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Mar 9, 2013 8:42 PM CST
|The question is:|
Is the following how we get different looking seedlings from a cross?
Now, perhaps the stupid thinking on my part. Please bear with me.
I know, sometimes I shouldn't think too much. LOL.
The top of the pistil has 3 lobes with 3 connecting hollow tubes that go to
3 ovaries. So, you place pollen on top of pistil, but each grain of pollen has
varying degrees of genetics. When the ovary develops and produces the seed pod which has 3 chambers, does one chamber have seedlings that resemble each other? Say you have chamber 1, 2, and 3. Chamber 1 seeds produce seedlings that are a similar pastel. Chamber 2 seeds produce seedlings that are similar yellow blooms, and Chamber 3 produce seedlings that are off the chart variations of red. Is this anywhere near how we get different seedlings from the same cross?
Mar 9, 2013 8:51 PM CST
|Sorry, Shirlee - you have me confused. If your using the same pollen, how are the different chambers going to end up being pastel, yellow and red? If your using different pollen, how are you going to get the pollen on just one chamber?|
Mar 9, 2013 9:01 PM CST
|Juli, I am thinking a different pollen grain goes down each tube, one grain into each.|
Same pollen applied, just different grains of that same pollen carrying varying genes.
When I make a cross, I get different looking seedling bloom on some, even color, and am
wondering why that is.
Name: Elizabete Rutens
Mar 9, 2013 9:06 PM CST
I'm really glad that you posed the question, since I've wondered about it, too! Are seeds collected from one chamber of a pod more similar to each other than they are to seeds from the other chambers? I've never kept the seeds collected from each chamber separated to see what the seedlings ultimately produce. I hope someone has the answer!
All the best - Elizabete
Mar 9, 2013 9:09 PM CST
|Thanks Elizabete, you stated that with far more clarity than I did. |
And you have given me an answer. To separate the seeds from each chamber, observe,
and document just in case someone else hasn't already done this.
Mar 10, 2013 5:58 AM CST
|This is way above my head!!|
Name: Elizabete Rutens
Mar 10, 2013 8:40 AM CST
|Fred, thanks so much for your feedback! (And I mean that sincerely!)|
Another way of asking the question: do individual seeds in a single chamber of a seed pod have an identical genetic makeup contributed from the pod parent? My understanding (which perhaps is wrong) is that each seed in the chamber will have a different grain of pollen that helped create the individual seeds. But, is the pod parent’s genetic contribution the same for all of the seeds in that single chamber? Or is the pod parent’s genetic contribution just as random as the pollen parent’s?
For my part, I’m just trying to figure out how a daylily seed is created. I have read the literature, but I’m still confused, unfortunately.
All the best – Elizabete
Mar 10, 2013 8:42 AM CST
|Each egg cell combines with one grain of pollen, no matter where in the ovary, to make a seed. Each seed will be it's own individual.|
Mar 10, 2013 9:21 AM CST
|Sunday has it. |
It is like each puppy in a litter has unique genetics that is a combo of the two parents, so does each seed in the seed pod.
For humans, the analogy would be paternal twins (each from their own egg so they can even be one male and one female)
Daylilies had three chambers but each contains several seeds. There should the same random genetic combo of the parents in each seed regardless of if they are in the same ovary.
Food for thought - just like dogs or cats can mate with more than one male and have pups/kittens in the litter from different fathers. Open pollinated daylilies can too!
Especially if they are bee polinated as the bee can be leaving grains of pollen from several different flowers it visited previously.
Love what you teach and teach what you love!
Grey County, Ontario (Zone 4b)
Mar 10, 2013 9:55 AM CST
|The seeds in one chamber are no more closely related genetically than seeds in different chambers. Each ovule in the pod is genetically different from every other ovule in the same pod.|
We get different seedlings, say for flower colour from the same pod (or cross) because daylilies are out-breeding instead of inbreeding. As examples, peas and tomatoes are inbreeding. So if I take the seeds from a Beefsteak tomato and plant them I will get more Beefsteak tomatoes. The seedlings will look like their parent. Basically Beefsteak tomatoes have been pollinating themselves for many generations and have created what is described as a "pure-breeding" line or strain (for characteristics that are important to us the consumers). The same thing happens with peas. If I take the peas from a pod of a purple flowered pea plant and plant them, the seedlings will all be purple flowered just like their parent. That is why Mendel was 'lucky' in the types of plants (peas) he chose to use in his breeding experiments (actually he checked his plants to make certain that they were pure breeding - it was not luck). It is important to know that if I take seeds from a plant that is described as an F1 hybrid or sometimes simply described as a hybrid then the seedlings will not be identical to the parent. Daylily cultivars are basically hybrids. When we hybridize a plant we deliberately force it to out-breed and that has been done with plants such as peas and tomatoes that normally inbreed by self-pollination.
A second reason we can get many different flower colours in the seedlings is that flower colour (and nearly all daylily characteristics we are interested in) are not based on simple genetics. There are probably between 30 and 100 (or more) different genes that influence flower colour. If there was only one gene and there were only two alternative flower colours (say red or yellow) then there would be much less variability in the seedlings from crosses.
As an imaginary example, for a diploid daylily, with only one gene for flower colour (but two chromosomes) and in the simplest case red dominant to yellow, RR is red, Rr is red (and indistinguishable from RR) and rr is yellow. If we cross red x red we might be crossing RR x RR so all the seedlings are red. Or we might have crossed RR x Rr and all the seedlings are red. Or we might have crossed Rr x Rr and approximately three quarters of the seedlings are red and one quarter are yellow.
If we crossed a red with a yellow we might have crossed RR x rr and all the seedlings would be red. Or we might have crossed Rr x rr and approximately half the seedlings will be red and half will be yellow.
But we don't have such a simple case in daylilies. They can be near-white, lavender, pink, purple, yellow, orange, peach, red, etc. The more genes that affect the characteristic, in this case flower colour the more alternative flower colours the seedlings can show (depending on what flower colours the parents show). For some flower colours, usually the lighter colours, there is usually less variability in the seedlings. For example, if we cross one yellow flowered daylily with a different unrelated yellow flowered daylily we expect that all the seedlings will be yellow flowered (more or less - they might vary from near-white, light yellow, or cream, to lemon yellow, etc. depending on the ancestry of both yellow parents). A red flowered daylily might carry the genetics for yellow, and pink or lavender, etc all hidden by the red colour.
If we look at tetraploids the situation becomes even more complicated. Now there are four chromosomes and therefore instead of the simplest diploid case of RR, Rr and rr we now have RRRR, RRRr, RRrr, Rrrr, and rrrr. The genetics becomes very complicated because although RRRR may be red and rrrr may be yellow each one of Rrrr, RRrr and RRRr often may be a different shade of red.
Now back to the original question. yes there are three lobes on the stigma and yes there are three chambers in the pod but there is only one channel in the style through which the pollen tubes grow. The three stigmatic lobes and the three chambers share that channel. So even if one placed pollen from a yellow flower on one lobe and pollen from a red flower on another lobe and pollen from a near-white flower on the third lobe the pollen tubes might cross-over and not grow straight down so that each chamber might produce mixtures of seedlings with different coloured fllowers. We do not know if many of the pollen tubes do grow straight down or how many do since the experiment has not been done and published.
Mar 10, 2013 10:45 AM CST
|Thanks for the wonderful and informative replies everyone.|
Admmad, I sometimes have stigmas that split, and intentionally pollinated one last season
anyway. Unfortunately, I later forgot about it. I thought it set a pod, but I'm not at all sure.
So, since the three stigma lobes share one channel in descending to the ovaries, a split
stigma is not viable, correct? Also, we could not accurately say that there are three styles? Or
is it that there are three styles linked together, but only one channel? I can't picture this in
my mind when I think of a split stigma.
Grey County, Ontario (Zone 4b)
Mar 10, 2013 12:41 PM CST
|If we look at the way that the pistil develops in the bud we can get an idea why sometimes there are three separate styles each with their own stigma. We find that early in development there are three that start to develop and that a little later they normally fuse together into one. A split stigma indicates some sort of defect or problem occurred during development that caused them to not fuse properly. Sometimes that may mean that the separate styles do not have proper channels within them and sometimes one or more of the separate styles might have a proper channel. However, even if the styles have proper channels there may be other developmental problems in other parts. |
Sometimes one or more of the separate styles/pistils might produce good seeds if pollinated but that might be different for each flower with a split pistil and might be different for different cultivars.
In a normal flower there is only one style and one stigma but the stigma normally has three stigmatic lobes. Sometimes a pistil may have a fourth stigmatic lobe (smaller than normal) and sometimes those lobes are not at the top of the pistil but part of the way along the style. So sometimes the pods that develop have more than three chambers even when the flower was not obviously a polytepal with more than three petals and three sepals (or more than six tepals) and possibly more than three stigmatic lobes in the normal location.
If the pistil is split then the abnormal flower could be described as having three pistils and three styles, etc.
Mar 10, 2013 2:10 PM CST
|Thank you so much for that very thorough explanation, Admmad.|
I won't be pollinating any more split pistils. Don't want any developmental
problems showing up in the seedlings.
Even though I was trying to gain more control over particular characteristics of any
given seedling, I understand how it is more of a 'what you see is what
you get' factor while some characteristics are more easily attained than others.
Mar 11, 2013 5:39 AM CST
|It's good to have people here that can explain this sort of thing so that we can understand it.|
Mar 11, 2013 9:04 AM CST
|Admmad, thanks so much for the explanations!|
Mar 11, 2013 11:57 AM CST
|There certainly is so much good info here, Julie. My old plant biology texts, and |
searching the net did not provide as much detailed inclusion of daylily parts and their
relationship to one another as is explained here.
Mar 11, 2013 3:50 PM CST
|The info in this thread has been fascinating, and I know more people would click if they knew what was in here!|
Mar 11, 2013 3:56 PM CST
|This is the first time I've ever actually understood anything I've read that was written on this topic. Have you ever read one of those "for Dummies" books? I love the ones I've read, and stuff will actually make sense to me afterwards. I found the same exact thing on this thread! Not that anyone here is a dummy, but I know many of us are confused when it comes to this stuff, and now I'm a lot less confused thanks to the information from admmad!|
Apr 19, 2013 10:21 PM CST
I figured that hybridizing season is just around the corner for many of us, so this deserved a bump, in case anyone missed it. Great information here!
May 8, 2016 3:54 PM CST
|One particular daylily has all it's stamens fused to the petals. Anyone know why this would happen?|
. Thanks in advance for any help.