"Kay Easton" wrote in message
...
In article , Brian
writes
Seeds from white bluebells will only come true if pollinated by other
white
flowers. This is best done by hand and cover the fruits after you have
done
so. Ideally do this in an insect proof greenhouse. From where will you
obtain the white genuine bluebells to make a start?.
Have another look at English bluebells in dappled sunlight and you might
agree that the natural colour is the best. I have literally millions of
bluebells forming glades and think of the other colours as interesting
but
not desirable in bulk.
Is that true? Someone else said that the white gene was recessive. That
would mean that a bluebell with a blue gene and a white gene would have
blue flowers. But if you mated two such bluebells, around 1 in 4 of the
offspring could be expected to be white - and that's how you get the
white one to begin with.
So while a white bluebell will come true from seed if pollinated by
another white one, you should still get a proportion of white flowered
bluebells (approx half) if it is pollinated by a bluebell with one white
gene and one blue gene.
Of course, finding out which of the blue bluebells have a white gene is
another matter entirely ..
Kay~ Many thanks. Your ratios are quite correct for a colour determined by
a single pair of alleles. As you say they would be 'AA' for a normal
bluebell, 'aa' for a recessive and 'Aa' for the bluebell that looks normal
but is hybrid. So Aa x Aa = 1AA: 2 Aa: 1aa[white]
Also as you state Aa x aa = Aa : aa. and again the difficulty would be in
recognising the Aa ~~ which is impossible.
However the white requires two pairs of recessive alleles and gives a ratio
of 15 : 1 and then only having crossed [or self pollinated] a pair of
dihybrids.
For example pure blue would be 'AABB' 'and the white 'aabb'. The first
cross would be dihybrids 'AaBb'. Crossing two of these is not terribly
complicated mathematically but does give a ratio of 15 coloured to 1 white.
AABB:2AABb:AAbb:2AaBB:4AaBb:2Aabb:
aaBB:2aaBb:aabb. So only the aabb will be white. Those showing the A&b can
be pink as can those showing a&B but differing slightly. Nine will look the
normal blue.
So you can see why it was suggested that he tries to self pollinate two
whites?!!
Incidentally, the is a ng in which bottom posting is the norm, and if
you top post it gets the whole thread into a complete scramble.
Thanks for your question and Best Wishes
Brian 'flayb' to respond.
news
On Sat, 15 May 2004 13:53:43 +0100, "Brian"
wrote:
There are a number of genes involved in the flower colour of
bluebells.
Pink
is recessive and can be passed through numerous generations till Xed
with
another carrying the same recessive gene. 5 years is ample time. There
is
another .doubly recessive, gene that can produce white flowers.
Neither
of
these indicates being infected with alien species. An ultra rare
combination
of alleles can increase the intensity of pink to magenta~or dilute
till
barely shell pink.
They are not more common because the genes are recessive, and doubly
recessive, and it is highly probable that the insects involved have an
instinctive preference for the blue.
Best Wishes Brian
We have a single, white, regrettably Spanish bluebell in our garden
(I've eliminated all the blue ones, and am growing English bluebells
from seed collected late last summer, but they only germinated earlier
this year). As I like the white one, I was hoping to collect the seed
and increase the numbers. Are they likely to come true?
--
Chris
E-mail: christopher[dot]hogg[at]virgin[dot]net
--
Kay Easton
Edward's earthworm page:
http://www.scarboro.demon.co.uk/edward/index.htm