This is a public-interest archive. Personal data is pseudonymized and retained under GDPR Article 89.

Re: Genetics

Rick- I can't currently find any specific references to fruit size
genetics, but I do remember being presented last year with a similar
concept to that which I used before about a theoretical few size genes.

Looking at it in a molecular biology light, the genes ABCDEFGH I used are
in fact hundreds/thousands/millions of genes in the pumpkin which
contribute to increased growth of fruit.

The (simplified) central dogma of molecular genetics is that a gene codes
for a protein, which does something with a certain efficiency- eg traps
carbon dioxide to make sugars. A small change in the protein- brought about
by a mutation to the gene- may cause it to become more or less efficient. A
big pumpkin must have a reasonable collection of efficient genes. And
especially, genes which

By classic Mendelian genetics, if the more 'good' genes a pumpkin has, the
larger its fruit will be, then by crossing two different strains, some of
the offspring will have more 'good' genes than their parents, and so be
able to produce bigger fruit.

I doubt it's completely additive, and I'm sure it's not complete dominance-
and as I'm sure any of the pumpkin growers here would agree, the amount of
care a pumpkin gets will influence the size of its fruit. That is, the
phenotype "big fruit" is multifactorial.

As for maternal inheritance, that may well have an effect on the
extranuclear genes- but as these are conservative, I doubt much effect
would be notices. I can't say much for parental imprinting- as far as I
know that's still a gooey subject. More important may be the 'care' given
to the seeds by the mother plant- one which endows its seeds well would
produce healthy seedlings, and so these might hasten the juvenile growth.
What do you think of that idea? (i can't find much basis for it, but it
sounds good, anthropomorphically, if nothing else.)

I'll see if I can research the subject a bit more, and maybe chat with a
pea-geneticist I know.

Regards

Vanessa.

Oh, I just remembered, peas have 'early' and 'late' flowering genes. If you
want a big pumpkin you want the plant to flower as early as possible. So
crosses could be used to promote this...
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index