Re: Apomicts (fwd)
- To: Multiple recipients of list AROID-L
- Subject: Re: Apomicts (fwd)
- From: S* M*
- Date: Wed, 29 Nov 2000 15:00:38 -0600 (CST)
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Sender: Claude Sweet <sweetent@home.com>
Subject: Re: Apomicts
Generating viable seed is not the issue, it is the genetic material that
is different in a hybrid (out crossing) or selfed seed. Apomictic seed
is identical to the female parent. This can be caused by duplication of
genetic material of the female parent that produces a seed without male
genetic input. In fact, if pollen is applied, the genetic material is
not accepted.
Some plants produce seed both through pollination (hybrid seed) and
identical to the female parent (parthenogenesis). An example would be
mangoes.
I don't know if in aroids there is one dominate gene that causes
apomictic seed to be produced or if it is recessive. It would depend on
the source of the genetic material (1N or 2N). I can assure you that the
apomictic seed has a full compliment of genes - as the seed is an exact
duplicate of the 2N female parent by definition.
If the trait is recessive, the pollen from an apomictic female plant
could be used to pollinate a non-apomictic plant to produce hybrid seed.
This is because the pollen produced by the apomictic female plant is 1N
(only carrying half of the genetic code necessary to produce a viable
seed).
Hybridizing could be more complicated if multiple genes are involved in
the expression of apomictic seed.
As parthenogenetic seed and hybrid seed can be produced in the same
mango fruit, the genetic transfer may also be related to external
stimulus such as temperature.
Oriental persimmon fruit can be seedless (a parthenogenetic process) in
California, but does not seem to be observed in Florida.
If you want a detailed explanation for the purpose of plant breeding,
you should consult with someone in the plant science department of your
local university.
Claude Sweet
San Diego, CA
zone 10
Jay Vannini wrote:
>
> Keith:
>
> Indeed, my understanding of these plants is that they CAN generate viable
> seed without manual fertilization. I am aware of at least two Anthurium spp.
> that often generate seed thusly - A. clarinervium & A. papillilaminum.
> Surely, there are many more.
>
> With regard to Claude Sweet's comment - it is worth noting that both of
> these Anthuriums have been utilized by aroid hybridizers for some time, and
> that the former species is suspected of being one of the parents of A.
> leuconeurum. I have manually pollinated both of the above, and have
> generated viable seed either way.
>
> Regards,
>
> Jay
