cross pollination of vegetables
Stewart Robert Hinsley writes
In message ,
In the majority of flowering plants the embryo sac (female gametophyte)
ends up with 7 cells contained 8 haploid nuclei. The pollen grain (male
gametophyte) has 3 haploid cells - the vegetative cell, and two sperm
cells. When the pollen grain germinates the vegetative cell grows down
the style to reach the embryo sac, carrying the two sperm cells.
One sperm cell unites with one cell from the embryo sac. The resulting
diploid cell develops into the embryo. The other sperm cell unites with
the embryo sac cell with the extra nuclei. This develops into a
triploid tissue - the endosperm - which is many plants provides
nourishment for the embryo after seed germination. (In many other
plants the endosperm is vestigial. There might be complications about
syncytia as well - I don't recall.)
Ah - right. This awakens memories of a long ago plant physiology course.
It all seemed very complicated, and I couldn't quite see the purpose for
making it so complicated, so buried it all in the back of my head
somewhere. So back to the text books for me! Thanks :-)
So, cross pollination would be significant in maize, and insignificant
in sweet peppers.
But, embryo and endosperm development start with a cell loaded with
proteins specified by the maternal genotype, including regulatory
proteins. Even in the absence of genetic imprinting (as occurs in
mammals), it would take time for the parental genotype to exert an
influence.
On the other hand, traits in tissues of the maternal genotype might be
influenced by cellular messages produced in the embryo or endosperm, so
it's not impossible that the genetic material in the pollen might
effect the development of the fruit. Like Nick I don't know whether any
specific such mechanism are known.
Oh well, I shall just have to hope. Hot sweet peppers I can cope with,
even non-hot chilli peppers. Strange tastes might be a different matter.
--
Kay
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