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-   -   Phal. Leuddemania won't flower (https://www.gardenbanter.co.uk/orchids/81842-phal-leuddemania-wont-flower.html)

Pat Brennan 19-08-2004 05:40 AM

Hi Claude,

Not a dumb question.

To understand the difference you have to understand what is going on with
the selfing. Genetically plants have pairs of chromosomes. In the sex
process, eggs and pollen are made with one of the chromosomes from the pair.
The two join creating a plant with a pair of chromosomes (one from the egg
and one from the pollen). If the plant we wish to self has the following
chromosome pair Xx, the resulting offspring will have Xx, XX, and xx for
chromosome pairs. The probability that a selfing will have the same
chromosome pair as the mother is .5. A Phalaenopsis has 38 pairs of
chromosomes. Thus the probability that a selfing will have the exact same
genetic make up as the mom is .5 to the 38 power which is something like 1
in 274 billion.


Pat


"Claude" wrote in message
...
hello everyone!

Sorry, might be a dumb question but...

what is the difference between selfing and cloning?

My understanding is that selfing is pollinating the plant with it`s

pollen,
that way, you get seeds and can go flasking.
Cloning is taking cells from a part of the plant ang grow it in flask!

Am I right? If so, what are the difference?

Thanks

Claude




Pat Brennan 19-08-2004 05:40 AM

Hi Claude,

Not a dumb question.

To understand the difference you have to understand what is going on with
the selfing. Genetically plants have pairs of chromosomes. In the sex
process, eggs and pollen are made with one of the chromosomes from the pair.
The two join creating a plant with a pair of chromosomes (one from the egg
and one from the pollen). If the plant we wish to self has the following
chromosome pair Xx, the resulting offspring will have Xx, XX, and xx for
chromosome pairs. The probability that a selfing will have the same
chromosome pair as the mother is .5. A Phalaenopsis has 38 pairs of
chromosomes. Thus the probability that a selfing will have the exact same
genetic make up as the mom is .5 to the 38 power which is something like 1
in 274 billion.


Pat


"Claude" wrote in message
...
hello everyone!

Sorry, might be a dumb question but...

what is the difference between selfing and cloning?

My understanding is that selfing is pollinating the plant with it`s

pollen,
that way, you get seeds and can go flasking.
Cloning is taking cells from a part of the plant ang grow it in flask!

Am I right? If so, what are the difference?

Thanks

Claude




Leo 19-08-2004 09:17 AM

"Claude" wrote in message ...
hello everyone!

Sorry, might be a dumb question but...

what is the difference between selfing and cloning?

My understanding is that selfing is pollinating the plant with it`s pollen,
that way, you get seeds and can go flasking.
Cloning is taking cells from a part of the plant ang grow it in flask!

Am I right? If so, what are the difference?


Not a dumb question, but there is a difference:

In selfing there is only one parent but it's still sexual reproduction.
The plant has two copies of each gene which may be different (alleles).
Each pollen grain and each egg contain one copy of each gene and the
choice is independent each time, so you get different combinations when
they are put back together in selfing.

Each time you self, for each gene, there is a chance that the offspring
will get two copies of the same allele (homozygosity). This means that
for that gene there is nothing to vary when that offspring is selfed (it
will 'breed true' for whatever characteristics that gene determines).
If you self repeatedly, you'll end up with a plant that is homozygous for
all genes, and if you self that its offspring will effectively be clones.

They will also be fully inbred (which is the same thing as fully homozygous)
which is something vegetative clones aren't necessarily.

Leo

Leo 19-08-2004 09:17 AM

"Claude" wrote in message ...
hello everyone!

Sorry, might be a dumb question but...

what is the difference between selfing and cloning?

My understanding is that selfing is pollinating the plant with it`s pollen,
that way, you get seeds and can go flasking.
Cloning is taking cells from a part of the plant ang grow it in flask!

Am I right? If so, what are the difference?


Not a dumb question, but there is a difference:

In selfing there is only one parent but it's still sexual reproduction.
The plant has two copies of each gene which may be different (alleles).
Each pollen grain and each egg contain one copy of each gene and the
choice is independent each time, so you get different combinations when
they are put back together in selfing.

Each time you self, for each gene, there is a chance that the offspring
will get two copies of the same allele (homozygosity). This means that
for that gene there is nothing to vary when that offspring is selfed (it
will 'breed true' for whatever characteristics that gene determines).
If you self repeatedly, you'll end up with a plant that is homozygous for
all genes, and if you self that its offspring will effectively be clones.

They will also be fully inbred (which is the same thing as fully homozygous)
which is something vegetative clones aren't necessarily.

Leo

James Aldridge 19-08-2004 02:07 PM

As an aside, it's worth mentioning that many flowering plants, perhaps
as many as 50% or so of all species, are polyploid. That is, they
carry more than two copies of each chromosome and therefore more than
two alleles of each gene.

Polyploidy is often a good thing in that it may confer larger size and
more robustness. It is sought in some orchid breeding by using agents
such as colchicine that inhibit proper chromosome behavior during cell
division.

Jim

Claude 19-08-2004 02:25 PM

Thanks everyone!

Claude

"James Aldridge" wrote in message
...
| As an aside, it's worth mentioning that many flowering plants, perhaps
| as many as 50% or so of all species, are polyploid. That is, they
| carry more than two copies of each chromosome and therefore more than
| two alleles of each gene.
|
| Polyploidy is often a good thing in that it may confer larger size and
| more robustness. It is sought in some orchid breeding by using agents
| such as colchicine that inhibit proper chromosome behavior during cell
| division.
|
| Jim



Claude 19-08-2004 02:25 PM

Thanks everyone!

Claude

"James Aldridge" wrote in message
...
| As an aside, it's worth mentioning that many flowering plants, perhaps
| as many as 50% or so of all species, are polyploid. That is, they
| carry more than two copies of each chromosome and therefore more than
| two alleles of each gene.
|
| Polyploidy is often a good thing in that it may confer larger size and
| more robustness. It is sought in some orchid breeding by using agents
| such as colchicine that inhibit proper chromosome behavior during cell
| division.
|
| Jim




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