Betr: Re: arisaema hybrids

[pbruggeman at TISCALI.NL]

My concern that Jim McClements is probably referring to is that, in my op=inion,
the current attempts to produce hybrids have rarely produced plants of an=y
horticultural value but yet might become the future source of pollution
of the genepool. The current attempts seem to be done out of curiosity bu=t
most of us know that professional hybridizers never cross without a speci=fic
result in mind and always have a well-thought out breeding program. Altho=ugh
the outcome of a cross can never be fully predicted, they will always try=
to minimize the number of inferior plants and have a clear idea of what
is feasable and desirable. With crosses never flower A will be attached
to plant B, the hybrid always has some intermediate characters, breeders
rarely succeed in combining the best of both parents. You must remember
that most of the taxonomic confusion in other genera is not caused by the=
professionals but by amateur breeders!

Thusfar, and that is purely subjective, I have not seen a single hybrid
that is more attractive than any of the  parents. The risk however is tha=t
these "inferior" hybrids will continue to be cultivated and are a possibl=e
source of pollen. With many people growing increasing numbers of species
(mostly in the open garden) and contributing to seedexchanges, the number=
of hybrids grown from a seedex will increase. With the F1-hybrids already=
there, the results might even be F2-hybrids. Expecting to sow sikokianum
and ending up with a cross after 3-4 years of blood, sweat and tears will=
for many be a major disappointment (and who can improve on sikokianum?!)

It has become clear that quite a number of species are prone to hybridiza=tion
(particularly the serratum-group and section Sinarisaema) so for me every=
seed from a seedex produced in an open-pollinated situation is a risk-fac=tor.
If seed has to be true to the parent, there is no other way to achieve th=is
than a controlled environment. Although breeders try to ovoid unwanted hy=brids
for a different reason, they too have to use a controlled environment.

I can understand that people want to try and create something new. I also=
understand that pollution of the genepool is inevitable with increasing
numbers of people growing increasing numbers of plants and if it is contr=olled
and well-documented, I see no harm in this. I do however am concerned abo=ut
the "failed attempts" which do not add anything to the existing range oth=er
than making seedexchanges less reliable and are a nightmare for people li=ke
me who deal with Arisaema-taxonomy. They can be avoided if more crosses
are attempted with at least some idea in mind instead of "hey..., let's
try to cross this with this" and well documented. Tony, "experimenting"
in a lab is always done with a clear idea and not luckwise, I hope you me=an
experimenting with an idea in mind?

Many of the described crosses on Arisaema-L might genetically not even be=
possible (the cross Tony described between heterophyllum and franchetianu=m
(wasn't it?) sounds very unusual and I have to admit, I didn't expect tha=t
to be possible) and the fact that viable seeds seem to be produced does
not necessarily mean the seeds represent a hybrid. It is a known phenomen=om
that plants might produce seeds "apomictally"whereby alien pollen induces=
the female plant to produce viable seeds true to the mother plants withou=t
the merger of the genetic material. Also, hybrids between non-related spe=cies,
often produce rather weak and disease-prone plants that are sometimes ste=rile.
Of course out of the 100 arbitrary attempts made 2-3 might be worthwhile
but at what cost? I am not saying it is impossible to produce a good hybr=id
but experiences thusfar suggest it is difficult with Arisaema to achieve
this

The cross made by Jai Yu between franchetianum and candidissimum seems mu=ch
more sensible to me and could indeed produce something healthy, attractiv=e
and interesting. Although it might be obvious I am a species purist from
my interest in Arisaema-taxonomy, I have made a similar cross between "li=chiangense"and
candidissimum to see how related these species are and check if they migh=t
represent a single variable species.  I have no doubt at least a small pe=rcentage
of that off-spring might have commercial value but all the inferior seedl=ings
will be thrown on the compost heap after assesment, healthy or not.

I am the last to say that crosses shouldn't be made (many of the species
we now know are the results of natural hybrids from the past) but not to
cause any unnecessary pollution of the genepool I would really wellcome
a more sensible approach by those on the AEG that produce hybrids. Arisae=ma
are not like orchids or Rhododendron! Some species introduced by Chen Yi
are actually very rare so why waste the genetic material of rare species
on crosses before we have enough material of the pure species to make tha=t
hybridization acceptable? I would rather see species that are well-establ=ished
in cultivation being crossed than rare ones and don't forget, entire popu=lations
have been robbed to provide collectors with sikokianum and don't expect
all the new Chinese introductions to be seed-grown! No matter for which
reasons crosses are made, please document them well and try to keep them
separate from the true species.

Pascal

>-- Oorspronkelijk bericht --
>Date:         Mon, 24 May 2004 16:53:47 -0400
>Reply-To:     "Arisaema Enthusiast Group (AEG) Discussion List (and othe=r
>hardy              Aroids)" <ARISAEMA-L at NIC.SURFNET.NL>
>From:         Tony Avent <tony at PLANTDELIGHTS.COM>
>Subject: Re: arisaema hybrids
>To:           ARISAEMA-L at NIC.SURFNET.NL
>
>
>Jim:
>
>        Thanks for the updates on Roy's work.  Are there any wide crosse=s
>in the
>group that you can tell?  I'm still growing species hostas and daylilies=.
>I don't think arisaemas have a chance of getting to that level if we all=
>started regular breeding programs.
>
>> Tony
>>
>>   nicely variegated leaves and spadices not unlike sikokianum in shape=.
>>
>> So far they seem to be longer lived than sikokianum, although not as
>>spectacular.
>>
>> I share Pascal Bruggeman's concern that the popularity of arisaemas as=
>>garden plants, together with what seems to be a readiness to interbreed=
>>(even between separate sections), may soon wipe out many separate speci=es
>>and turn our garden arisaemas into healthy mongrels!
>>
>> Jim
>>
>>
>>
>> Jim McClements
>> 50 S. Prestwick Ct, Dover, Delaware, 19904, USA, Zone 7a
>>
>Tony Avent
>Plant Delights Nursery @
>Juniper Level Botanic Garden
>9241 Sauls Road
>Raleigh, NC  27603  USA
>Minimum Winter Temps 0-5 F
>Maximum Summer Temps 95-105F
>USDA Hardiness Zone 7b
>email tony at plantdelights.com
>website  http://www.plantdel.com
>phone 919 772-4794
>fax  919 772-4752
>"I consider every plant hardy until I have killed it myself...at least
>three times" - Avent


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