Date: Thu, 11 Mar 1999 09:43:19 -0800 From: John Brittnacher <britt@epm.ucdavis.edu> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg751$foo@default> Subject: Re: Drosera hamiltonii
>In looking through in Index Semminum (seeds offered by
>botanical gardens to other botanical gardens), I found Drosera
>hamiltonii listed. Since I only have a little familiarity with the
>plant, I looked it up in Peter D'Amato's book to determine if I could
>grow it in the conditions here at the garden. He states that it
>rarely flowers (which I'd heard) and that it does not produce any
>seed, propagating from roots and stems. Is this really true? If so,
>the seed I'm being offered couldn't be D. hamiltonii. Can anyone out
>there enlighten me?
You might want to check out this paper (I have only seen this abstract).
If D. hamiltonii is self-incompatible then you would be able to get seed by
crossing non-related individuals. It would also explain why seed is not
recovered from other cultivated Australian Drosera. I don't think even
Peter has 2 unrelated Australian Drosera plants of the same species--well
not many anyway.
Self-incompatibility, seed abortion and clonality in the breeding systems
of several Western Australian Drosera species (Droseraceae)
Chen L, James SH, Stace HM
AUSTRALIAN JOURNAL OF BOTANY
45: (1) 191-201 1997
Abstract:
Western Australian Drosera L. species include one annual and many tuberous
and pygmy perennials. In 20 species or subspecies, 17 taxa were
self-incompatible (SI) and three were self-compatible (SC), as assessed by
patterns of seed set and pollen tube growth. All SI species were clonal
(tubers or gemmae), but two SC species were clonal (gemmae) and one was
annual. Self-pollen tube inhibition confirmed that SI species were
pre-zygotically self-sterile. The sites of SI pollen tube inhibition varied
from early (stigmatic) to fate (stylar, placental, ovular), which suggests
continuing evolution in the expression of the SI response. Self-compatible
species showed little inbreeding depression, but SI species showed
considerable inbreeding depression as measured by seed abortion. In the
three species tested, open-pollinated capsules were typically more fecund
than hand-pollinated capsules. In D. glanduligera Lehm., this might
represent position effects in an inflorescence that were reflected in the
sampling method. In other species, however, this might also reflect
biparental inbreeding depression in the glasshouse plants. Interspecific
crosses between D. tubaestylis N.Marchant & A.Lowrie (n = 14) and D.
rosulata Lehm. (n = 13) were slightly successful, with no pollen-pistil
incompatibility interaction, but with extensive seed abortion. This is the
first report of SI in Droseraceae.
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