Lump Doodia, Oceanopteris, and Neoblechnum?

[joelnitta]

The segregate genera of Blechnum s.l., Oceanopteris and Neoblechnum render each other non-monophyletic in FTOL 1.6.0.

Specifically, this is caused by Doodia maxima clustering with Oceanopteris gibba and Neoblechnum brasiliense.

The D. maxima sequence (DMU05921) is from Wolf et al. (1994). The specimen was cultivated at MOBOT, origin unknown.

The O. gibba sequence (MN623360) is a whole-plastome sequence from Liu et al. (2020). They also used a cultivated specimen (Fairylake Bot. Garden) and as far as I can tell didn't provide any data on the original source of the material.

According to Gasper et al. (2016), Neoblechnum is monotypic and sister to Doodia + Oceanopteris, which are sister to each other. Neoblechnum is only from the neotropics, whereas Doodia + Oceanopteris are from Malesia, Fiji, New Caledonia and Australia. However, they cite the need to study the relationships between Doodia and Oceanopteris in more detail, citing low branch support for the relationship of Oceanopteris to Neoblechnum in their tree.

I think at this point we can't say much more about this without having taxonomic experts examine the specimens in question, but I wanted to share my notes for future reference.

References

Gasper AL, Almeida TE, Dittrich VAO, et al (2016) Molecular phylogeny of the fern family Blechnaceae (Polypodiales) with a revised genus-level treatment. Cladisticsi. https://doi.org/10.1111/cla.12173 pdf

Liu S, Wang Z, Wang H, et al (2020) Patterns and Rates of Plastid rps12 Gene Evolution Inferred in a Phylogenetic Context using Plastomic Data of Ferns. Sci Rep 10:9394. https://doi.org/10/gg23kn pdf

Wolf PG, Soltis P, Soltis D (1994) Phylogenetic relationships of dennstaedtioid ferns: evidence from rbcL sequences. Molecular Phylogenetics and Evolution 3:383–392 pdf

[SoniaMolino]

Thanks for pointing that out Joel, in fact Michael Sundue and I are working on this - stay tuned! Also, I take this opportunity to make an appeal, if anyone has access to specimens of taxa within this group I would be happy to talk about it.

[DrAshleyField]

Hi @SoniaMolino and Michael, I have access to, and in several cases already have target sequence capture data of the Australian Doodia and a couple of Oceanopteris if this helps. @joelnitta the Blechnaceae gurus will assist further, but it is my understanding there has been discussion over the years that Doodia maxima is of hybrid origin. Ash

[SoniaMolino]

That's great, Ashley! I'll send you and email :)