Is it the same DNA or not?

[greenthumbnails]

Okay, so I understand that if you grow a new lily from seed that it is not the same plant or same DNA because the genome mixed with another plant during the pollination process that produced the seeds.

What about other means of propagation like for example in tropical lilies; you can get little side corms (which I still cannot figure out how they got there i.e. did it grow out of the main tuber, or did the main tuber put out a small plantlet, and then this plantlet grew a little tuber and went dormant underground) which produce a plant OR viviparous propagation.  I figure the vivip method is still the same plant, as it grew out of a leaf with the same DNA.  The side corm method though, I don't know...mostly because I don't understand how it got there to begin with.

Oh, and then there is the main tuber putting out little plantlets direct.  Those I figure are also the same plant, same DNA.

Any thoughts on this out there?

[Timgod]

If it is a form of vegetative reproduction from tubers, viivips etc then it is essentially a clone and the same.
A seedling is not the same in most cases.
If it is a species plant and it has been totally isolated or emasculated and covered to ensure only it's own pollen has a chance to set seed then you will get essentially the same plant.
A plant that reproduces itself exactly from seed is one of the main determinations for whether or not something is a species.

Tim

[greenthumbnails]

Very interesting. Thanks for the info Tim 

[Craig]

This may fall under semantics, but......vegetative propagation, and that includes tissue culture, does give you clones or genetically identical plants and vegetative propagation is the only way to get a true to type hybrid plant.  In short, you get the same plant, meaning the DNA is identical.

But a species is not an individual, it is a population of genetically similar organisms, so a species plant does not need to be pollinated by its own pollen to be true, pollen from any other member of the species will work equally as well.  Even then, whether it is self pollinated or pollinated by another of its species, the reproduction is never exact and the plant is never genetically identical the parent(s).  Meiosis divides the chromosome pairs in half and the recombination during sexual reproduction with a complementary, but genetically different pair whether from another parent or from its own gamete,if selfed, is what produces variability in a species.  You get a plant of the same species, but as far as DNA goes it is not the exact copy that vegetative propagation gives.

[mushrooms]

What about sports and also sports as a result of tissue culture?

[greenthumbnails]

This may fall under semantics, but......vegetative propagation, and that includes tissue culture, does give you clones or genetically identical plants and vegetative propagation is the only way to get a true to type hybrid plant.  In short, you get the same plant, meaning the DNA is identical.

But a species is not an individual, it is a population of genetically similar organisms, so a species plant does not need to be pollinated by its own pollen to be true, pollen from any other member of the species will work equally as well.  Even then, whether it is self pollinated or pollinated by another of its species, the reproduction is never exact and the plant is never genetically identical the parent(s).  Meiosis divides the chromosome pairs in half and the recombination during sexual reproduction with a complementary, but genetically different pair whether from another parent or from its own gamete,if selfed, is what produces variability in a species.  You get a plant of the same species, but as far as DNA goes it is not the exact copy that vegetative propagation gives.

Thanks for the further explanation Craig, it is more clear now. 

So is it safe to say that a "Truely Named Lily" is a cloned lily from the parent i.e. the source was through either viviparous or tuber propagation and that if one gets a lily that looks just like the parent plant, but if it was grown from seed from that plant (either self pollinated or pollinated by another plant nearby) that one cannot say that it is "Truely Named" because it is not the same plant (not same DNA)?  Or, for the purpose of being able to use that term, it can still be used as long as the plant is the same species (Species being interpreted as looks the same physically but DNA is different due to grown from seed)? 

I was also thinking...that little side corm that you find when you divide and repot a tropical - one really  cannot be sure whether it is a clone (plantlet that came off of the main tuber that then tubered itself) or if it is a new plant entirely (could have been a seed that dispersed and landed in the pot).  For all we know it may not even look like the parent plant in the same pot (not same species?) as it could have been a seed dispersed from a plant in the next pot over....

[greenthumbnails]

What about sports and also sports as a result of tissue culture?

Mushrooms - I am unfamiliar with the term "sports".  When I think sports, I am thinking of hockey and soccer....   Please explain term...

[frloplady]

If it is a form of vegetative reproduction from tubers, viivips etc then it is essentially a clone and the same.
A seedling is not the same in most cases.
If it is a species plant and it has been totally isolated or emasculated and covered to ensure only it's own pollen has a chance to set seed then you will get essentially the same plant.
A plant that reproduces itself exactly from seed is one of the main determinations for whether or not something is a species.

Tim

In apples for instance.. I'll even use one I'm familiar with..Golden delicious.  It can pollinate itself because it is because of recessive genes.  However if you take the SEEDS from a golden apple and plant them you will not get a golden delicious tree!  So I don't know if it works the same with water lillies or not. ??  Interesting either way!

[Craig]

Lol....I want to say it was Gen. MacArthur who said "no generalization is worth a damn....and that includes this one."

Yes Mushroom, sports are the exception to the 'vegetative propagation breeds true' rule, though I am not aware of any data that indicates tissue culture causes sports.  Sports....which, btw, result from mutation in  cells of the rapidly dividing apical meristem, are enough of a rarity, that they would not affect the nature of the 'Truly Named' program.  And as Sean pointed out, a goodly number of sports revert to normal.  The stability of a sport depends on the proximity of the mutated cell to the hub of the apical meristem.  The closer to the meristem, the more rapid the division, the greater number of chimeral cells produced...the more stable the mutation.

And since we are looking at exceptions, there are a handful of plant hybrids that have been back breed for so many generation ( fifty+ comes to mind) that they now breed true to type, so technically it is inaccurate to say the hybrid "always" breaks down in the F2 generation, but since none of the back bred plants I am aware of is a Nymphaea....the hybrid break down can be considered to be fact in those discussions.

In essence Greenthumb...maybe.<g>  Species are pretty much exempt by definition from concerns over sexual reproduction.  One defintion of a species is that they they do indeed breed true to type and that is because they share the same genome.  Hybrids by contrast are the progeny of sexual crosses between members of different species...so while in a species X species cross there is but one species involved as parents, hybrid crosses involve multiple species and there is no way of knowing which traits from the various parents will be expressed.  So even if an offspring resembles a parent....which always baffles me when it is said because it by definition has more than one parent...it cannot be said to be true to type.  But here again, that is not a function of the Truly Named program, it is part and parcel of the International Code of Nomenclature for Cultivated Plants (ICNCP).  Truly Named plants just abide by the tenets of that code.

[Mikey]

Craig: Can you explain how a tissue culture is taken?

I have a Ligularia tussilaginea (Leopard plant) and now reclassified as Farfugium japonicum 'Aureomaculatum'.  The plant has large green circular leaves with cream or yellowish spots.  As the plant grows and spreads, some of the forks that take off from the mother plant will have foliage with no spots.  What would be the cause of this?  When I divide the plant I always have to be careful to cut off sections with only spotted leaves.  I recently noticed a volunteer coming up several feet away and it must be from seed.  I notice the leaves on this volunteer are spotted.

[Craig]

Tissue culture...or micropropagation.. uses undifferentiated cells from growing point; typically root tips, auxiliary buds or the apical meristem.  The cells are grown in sterile cultures that allow them to continue multiplying.  A regimen of plant hormones and other chemicals (the protocol varies some plant to plant) are added to the cultures that stimulate the various parts of a plant to form, so the undifferentiated cells are transformed into small plantlets that are clones and genetically identical.  Lots of cells equals lots of plants, rather than propagating them a cutting at a time. So marketable numbers of plants are produced quickly.  Once they reach the appropriate growth stage they are taken out of culture and grown out for sale.

The tissue lab I use does grow Farfugium, but I'd have to look to see if they handle the 'Aureomaculatum'.  Looking at the name, it is a cultivar and means roughly 'Gold Spots'.  It is probably a sport of japonicum selected for the spotting and they are chimeral and they can be difficult to culture and tend to revert.  That is why variegated plants are nigh impossible to tissue culture.  The mutation is not in the nuclear DNA, so when they get the cells to propagate, most will be normal, some will grow all white ( until they die<g>) and very few produce the variegated trait.

I suspect you are seeing the them revert.  I know nothing of Farfugium, but if they spread by runners, the volunteer my be that or a piece that broke off and rooted.  That isn't to say that it can't be a seedling; I know some variegates throw a small percentage of seed that carry the trait.

[Mikey]

Thanks Craig.  I understood just enough to know I won't be growing any tissue cultures....