Re: apomixis vs parthenocarpy

From: Doug Burdic (dburdic@harborside.com)
Date: Sat Aug 12 2000 - 17:50:56 PDT


Date: Sat, 12 Aug 2000 17:50:56 -0700
From: "Doug Burdic" <dburdic@harborside.com>
To: cp@opus.hpl.hp.com
Message-Id: <aabcdefg2476$foo@default>
Subject: Re: apomixis vs parthenocarpy

Hi Tierney,

> Actually, parthenocarpy is the setting of seedless fruit, a totally
> different phenomenon than apomixis. Parthenogenesis is the same idea
as
> apomixis, but I've only heard that word applied to the animal kingdom.
Maybe
> apomixis is considered to be a kind of parthenogenesis undergone by
> plants...?
>
> And I don't know if there is a word for the setting of sterile seed.
> -Tierney
> San Jose CA

Thanks for this explaination. Now I know I must have missed
that day in class on purpose. ;) I was just looking over an old
(1980) 'A Dictionary of Botany' by Little & Jones and I think
I'll just rip out those pages that try to differentiate between the
two terms. Here are their definitions:

1. Apomixis: Reproduction, including vegetative popagation,
which does not involve sexual processes; the ability of plants to
produce seeds without fertilization.

2. Parthenocarpy: The natural or artificially-induced development
of fruit without sexual fertilization. Such fruits are usually seedless,
as in naval oranges and commercially grown bananas.

Hmm..So in this second definition, the minority of the parthenogenic
fruit that 'does' produce seed..this could actually be considered
'Apomixis' then? I think the people who make up these names
and are splitting hairs in this area and I'd hate to have to write
a essay explaining the difference on a final exam; think I'd just
sign my name to the test and walk out. LOL It's all a matter
of semantics and whose giving the presentation at the time as to
which term is used. There's a plant that you've got to check out
sometime, which is really an enigmatic example of these '2'
phenomenon (or is the same one?) called the Mangosteen. It
produces a 'fruit', which is not really a true fruit since it doesn't
go through a fertilization process, nor is there a true seed, yet
they sell Mangosteen 'seed' which is really a adventitious 'tuber'
(don't quote me on this) which behaves like a seed. The plant
produces both hermaphrodite and male flowers..no female
flowers, yet the male flowers, while having stamens and anthers,
bear no pollen. Very strange plant and it gives me a headache
once a year when I try to figure it out. Just thought I'd throw that
one in as an example of a plant that nobody really understands.
Very, very rare in cultivation, but obtainable.

The term for setting sterile seed..good question. Besides the
results of some hybridization, I can't think of one at the moment
but they must have made one up at sometime. I'll see what
I can come up with.

Thanks and take care,

Doug

Doug Burdic
dburdic@harborside.com
The Central Oregon Coast

----- Original Message -----

To: Multiple recipients of list <cp@opus.labs.agilent.com>
Sent: Saturday, August 12, 2000 3:26 PM

>
> Hi Doug,
> Actually, parthenocarpy is the setting of seedless fruit, a totally
> different phenomenon than apomixis. Parthenogenesis is the same idea
as
> apomixis, but I've only heard that word applied to the animal kingdom.
Maybe
> apomixis is considered to be a kind of parthenogenesis undergone by
> plants...?
>
> And I don't know if there is a word for the setting of sterile seed.
> -Tierney
> San Jose CA
>
>
> >
> > > Some plants produce seeds without pollination.
> > > This phenomenon is called apomixis.
> >
> >Formerly called 'Parthenogenesis' or 'Parthenocarpy', or
> >have they changed the terminology on me once again since
> >my days at the university? ;) They do this a lot I've noticed
> >over the decades.
> >
> >Best Wishes,
> >
> >Doug
> >
> >Doug Burdic
> >dburdic@harborside.com
> >
>
>



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