Cathy, the DNA analysis contained in Yukawa's D. suzukii publication, viewable at:
http://www.orchideen-forum.de/board/showtopic.php?threadid=8974&highlight=) shows what Yukawa states; that, based on the molecular characters tested, D. suzukii is distinct from the closely related species D. tobaense and D. cruentum. Yukawa had no reason to suspect that his D. suzukii was a hybrid, so he has not discussed this possibilty in his analysis. I showed his paper to researchers doing similar work at the Molecular Biology lab at Singapore University, and was told that you'd get identical results if "D. suzukii" was a hybrid. It is worth pointing out two things: a) As is usual in such work, only a single plant from each taxon was sampled, so the results do not allow for genetic variability within each taxon. b) The closer relationship of D.suzukii to D.cruentum than D. tobaense is consistent with D. cruentum being the pod parent, since the DNA used in the analysis was of ribosomal origin. This is consistent with D. suzukii being made in the Vietnam lowlands, since D. cruentum flourishes there but D. tobaense won't survive for long due to the high temperatures. Icones, DNA work has already been done, but methodology used tested the wrong question. It is currently impossible to PROVE that a plant is a hybrid by using DNA analysis... the best you can do is show that a specimen is intermediate between two species. This would be true if the plant was a hybrid or a true intermediate species. Further work doing a molecular phylogenetic analysis of the mitochondrial nucleic acids may supply informative results, but still wouldn't be absolute proof. You said: "Other facts may ultimately prove D.suzukii to be a hybrid." and "Peter's points seems to me to be a gut response to the thing, but without as yet any factual basis. He could be right, but that is not usually how learned people go about these things." Icones. how many facts do you want ? Unless you can find "D. suzukii" growing in the wild (all attempts failed so far) or get a confession from the originators (they're keeping very quiet, but you should see the smile on the face of the Vietnamese collaborator when he discusses the events at Nagoya), no-one will ever PROVE anything one way or the other. As for my response being a gut reaction..... true, but not quite correct.... it was someone else's gut reaction, not mine. I wouldn't normally be summoned to give my opinion on a hybrid. The originator of D. Peng Seng called me in because HE had a gut feeling that something was wrong. I visited his home. On his bench were several D. suzukiis in bloom (it hadn't been described at that time), his first-flowering hybrid (later to be registered as D. Peng Seng) and a range of D. cruentums in flower. His D. tobaense specimens were dying due of heat-stroke, but it didn't matter ... we were both very familiar with that species. He told me that HE wondered if D. suzukii and D. Peng Seng were the same thing. I told him I'd investigate. I have investigated, as thoroughly as I've been able to. I don't know how learned people go about these things, but what I did is to collect as many facts as possible, and then make an informed assessment. Andy, chime out. Stick to complex hybrids. Your posting only reveals your ignorance and your desire to cause mischief. Peter O'Byrne in Singapore _______________________________________________ the OrchidGuide Digest (OGD) [email protected] http://orchidguide.com/mailman/listinfo/orchids_orchidguide.com
