AG Skin & Flesh Color

During 1999, my main interest is working with Mendelian traits in AG. I
hope to concentrate mainly on these:

Skin color (external color)
flesh color
seed color
squash vs pumpkin (which is a combination of the above??)
seedling and vine traits (color, hairs, glands, leaf shape, etc)

  I have limited space. Roger, others, and my own experience suggest I
can study some of these using pots for roots so vine size is limited. 
  My main interest is the question of squash vs pumpkin. I welcome your
mail on the difference! Three of you have already sent me some data from
selfed plants. In one instance after extensive selfing of light skinned
fruit, Orange appeared and then later squash appeared, seemingly from no
where. 
  What is the ploidy of AG? Many crops are 2N (they get one chromosome
from Mom and one from Dad). Sometimes by accident in nature, 4n plants
arise. Such plants commonly have larger fruit, doubled blossoms, bigger
stems and the genetics is more difficult. Here are examples:
  Example 1: Given a selfed fruit on a diploid (2N) plant which is Aa 
where A is dominant and normal color and a is albino (white) (no
chlorophyll) (lethal; it dies because it can't make food). The seeds in
this selfed fruit will have this genotypic ratio 1 AA : 2 Aa : 1 aa 
(that last plant will die). So 3/4 of the plants will be normal
phenotype (normal green) and 1/4 will be white and die. 
  Example 2: Given the same thing in a 4N (tetraploid), when we self a
A/a;A/a flower, the seeds in the fruit have 9:3:3:1 ratio and only one
plant will die out of 16. 1/16th die. If you have ever tried to fill a
Punnett Square for Squash vs Pumpkin, then you easily realize that if AG
is tetraploid then it is harder to get lines of AG which are free of
Squash. Usually heterozygotes are healthier and bigger. Thus, as we
select for size we will also be selecting for squash IF SQUASH TRAITS
AID SIZE.  
  If you want to learn more, my site will teach such things when it is
done in a couple years. I get a few pages started each week. 
  I hope everyone can help me plan my 1999 work by sending me examples
from your experience and perhaps offer seeds of possible mutants. I know
some of you have worked on these problems for many years. I do not
expect to make any great progress myself, but we might find something
useful after we pool our observations.
  Rock Rivard sent some nice selfed pedigree data last night and I am
using that in a web page on fruit color. I hope to install the fruit
color page this week and will announce it here on Pumpkins list. 
  If you have looked at the CGC gene lists (some years old) you may have
notices these mutants of C. maxima.

bl blue fruit; semi-recessive to green
Hi hard rind inhibitor; [might reduce cracking??]
lo lobed leaves; recessive
Rd red skin color (what is this, I have never see a red pumpkin!)
St stripes run length of fruit.
v  light green young leaves - not lethal - ??might limit plant size??
ys yellow seeding (no chlorophyll) plant dies.
I-mc inhibits mature fruit color

In corn we have 5 genes that are required for purple seed color plus
modifiers of these. Pumpkin color may be just as complex.

We have 5 hard-working members in our Genetics@onelist.com group; please
join us. Just click here http://www.onelist.com/subscribe/genetics then
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-- 
Harold Eddleman Ph.D. Microbiologist.       i*@disknet.com 
Location: Palmyra IN USA; 36 kilometers west of Louisville, Kentucky
http://www.disknet.com/indiana_biolab



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