Evolutionary history of Cocos etc

[Hugh Harries]

Alain

As a start you should read the appropriate sections in the recently published second edition of Genera Palmarum (Dransfield, J., Uhl, N.W., Asmussen, C.B., Baker, W.J., Harley, M.M. and Lewis, C.E. (2008) Genera Palmarum. Second edition. Kew Publishing).

Although I have reservations about the relationship of Cocos nucifera with any South American genera (South  Africa or Madagascar connections seem  more likely to me) perhaps you work will throw light upon the question.

But how will you propagate the first GM generation? Coconut tissues are remarkably recalcitrant to in vitro culture techniques.

Best wishes

Hugh
=== =

23/12/2008 18:11        from eightp...@gmail.com
alain huitdeniers Trinidad, Guyana, Eastern Venezuela. Need to acquire
a reasonably comprehensive picture of the evolutionary history of
Cocos, Syagrus, etc... including the possible history of the genome(s)
of group with a view to producing GMOs by gene tranfer at the level of
large chromosomal fractions.

[Hugh Harries]

Charles

Here is a taster from Genera Palmarum 2

BIOGEOGRAPHY
Historical biogeography of palms
Cocoseae Tribe (p. 116-117)

Cocoseae has long been of biogeographic interest, first because of uncertainty surrounding the origin of the coconut and, second, on account of the numerous cocosoid fossils that have been found within and beyond the tribe's modern natural range. Fossil evidence indicates that the tribe was present in South America, India and New Zealand during the Tertiary (Gunn 2004). Today, the Cocoseae is the most widespread palm tribe in the Americas; the majority of cocosoid genera and species occur there and their diverse ecological adaptations allow them to occupy both seasonal and ever-wet habitats. However, the tribe is also represented in the Old World by two genera in Africa and two in Madagascar. The coconut, Cocos nucifera, has a pantropical distribution, which is due to movement by man and water dispersal. Prevailing opinion suggests that it originated in the western Pacific (Harries 1978), but many other locations have been suggested (Gunn 2004). In addition, subfossil remains indicate that a genus of cocosoids, Paschalococos, a member of the Attaleinae closely allied to Jubaea, was present on Easter Island approximately 800 years ago (Dransfield et al. 1984) . . .

So far I cannot disagree

. . . It is reasonable to suggest that the group is most likely to have originated in the Americas in the broader sense and that at least three dispersals have occurred: 1) to Africa in Elaeidinae, 2) to Madagascar, Africa and possibly beyond early in the history of the Attaleinae, and 3) to Easter Island. This pattern cannot, as has been previously suggested (Uhl & Dransfield 1987, Hahn 2002a), be linked to Gondwanan break-up. The coconut almost certainly has a complex history of natural dispersal, now clouded by human intervention. We may never know with certainty where the coconut evolved and precisely how it achieved its modern extent.

But I am treating those last three sentences as a personal challenge - watch my smoke!

Happy New Year

Hugh

2008/12/25 Charles R. Clement <charlesr...@yahoo.com.br>

Hugh and Alain,

Remember Bee Gunn's THE PHYLOGENY OF THE COCOEAE (ARECACEAE) WITH EMPHASIS ON COCOS NUCIFERA. ANN. MISSOURI BOT. GARD. 91: 505–522. 2004.

ABSTRACT: The tribe Cocoeae contains economically important palms including Cocos nucifera, Elaeis guineensis, Attalea speciosa, and Bactris gasipaes. This study, based on the nuclear prk gene sequence, addresses the monophyly of the subtribes of Cocoeae, the closest relatives of Cocos nucifera, and biogeographical implications of its distribution. The Cocoeae are divided into the spiny and non-spiny taxa. Molecular data alone suggest that Cocos nucifera did not originate in the western Pacific; it may be the only extant member of its lineage. Several Cocoeae fossils from New Zealand and India were used as calibration points to estimate times of divergence of clades. A hypothesis for the origin of the Cocos clade based on the phylogeny was postulated. It is hypothesized that Cocoeae originated from South America, diversified and radiated eastward toward Africa, Madagascar, and India, and southward to Australia and New Zealand via the Antarctic corridor. The estimated divergence dates were corroborated with major tectonic events.

I don't yet know how this agrees with Genera Palmarum 2 (my copy is still in the Christmas mail), as Gunn used only one gene and I believe that Asmussen et al. used several segments.

Merry Christmas and Happy New Year to all.

Best regards,
Charles R. Clement

Alain
As a start you should read the appropriate sections in the recently published second edition of Genera Palmarum (Dransfield, J., Uhl, N.W., Asmussen, C.B., Baker, W.J., Harley, M.M. and Lewis, C.E. (2008) Genera Palmarum. Second edition. Kew Publishing).
Although I have reservations about the relationship of Cocos nucifera with any South American genera (South  Africa or Madagascar connections seem  more likely to me) perhaps you work will throw light upon the question.
But how will you propagate the first GM generation? Coconut tissues are remarkably recalcitrant to in vitro culture techniques.
Best wishes
Hugh
=== =

23/12/2008 18:11        from <mailto:eightp...@gmail.com>eightp...@gmail.com

[Hugh Harries]

Alain

I will reply in more detail as soon as possible but for now this is a quick response to your request:

I really need to know how to coax a palm callus into differentiation. If anyone has literature or know-how; well... please share.

The Google coconut knowledge network has over 400 members and is also browsed by non-members. So please write or reply to the group at <coc...@googlegroups.com> rather than to me.

Your topic makes a good opener for 2009.

Hugh

2009/1/1 eight pennies <eightp...@gmail.com>

Hugh,

Thank you (and Charles) for your help.

The biogeography (and thus evolution) of hydrochorous riparian & beach palm lifeforms is intrinsically difficult (the fossil distributions of Nypa, Mauritia, for example; the modern distribution of Manicaria saccifera & Raphia taedigera...); but, still, it's really hard to see how a fully evolved "coconut" form could've made it out of cisandean South America after the uplift.

All this has some relevance in the context of what I'm really after.

I'm considering somatic cell hybridization of material from within (but not exclusively so) the Cocoseae (btw... what are the currently accepted evidence-based names for suprageneric groupings within the Arecoideae?). Then, lengthy introgressive somatic cell hybridization back to the "home" species. During this ordeal, extensive chromatin and genomic fragmentation and reorganization occurs (at least it does in groups I'm familiar with -  including Heliconia & mammalian hybrids).

I really need to know how to coax a palm callus into differentiation. If anyone has literature or know-how; well... please share.

The benefits of introgressed lineages are potentially many. For example, in Trinidad, Raoiella indica has, in a blitzkrieg, destroyed a once-viable coconut industry. Yet in coconut plantations that were hard hit with serious concomitant infestations of a non-palm reservoir host: Heliconia psittacorum - the palms Bactris major, Desmoncus orthacanthos & Roystonea oleracea were virtually (or actually) untouched. Can this invulnerability be transferred in one or two genes? Perhaps. Perhaps not.

It is possible that the same fate awaits Guyana & Venezuela.

Additionally, imagine if genes for salinity resistance can be transferred from coconut to Manicaria or Mauritia or Astrocaryum vulgare for example. These are all underutilized oil & fibre neotropicals that could have tremendous potential for planting on already degraded peaty, saline coastal meadows that perhaps threaten to become even more inhospitable to plantation agriculture in the context of anticipated sea-level rise.

Regards,


alain (...and Happy 2009 everyone!)

2008/12/25 Hugh Harries <hugh.h...@gmail.com>

[Hugh Harries]

Alain

I cannot resist responding when you say:

" . . . it's really hard to see how a fully evolved "coconut" form could've made it out of cisandean South America . . ."

Surely, nuts drop into the sea and float off in all directions?

If only it was that simple!

Indeed, it could be made simpler than that, if we could accept:

1. that the first fully evolved coconuts were TAKEN to South America (both cis-andean AND trans-andean) about 500 years ago; and
2. that NO ancestral coconut has EVER grown on continental South America AT ALL.

I am not joking and nor am I put off by the Genera Palmarum editors when they say " . .  . its immediate ancestors were almost certainly South American" or by their about-face on dispersal "This pattern cannot, as has been previously suggested . . . be linked to Gondwanan break-up".

My explanation, briefly,  is as follows:

The "immediate ancestor" in question was NOT a "primitive" coconut;  it was a single, and successful, "general purpose ancestor". It was the one ancestor from which ALL other related genera derived. It grew on the Gondwana super-continent and, due to their proximity, it dispersed successfully into the areas that were to become the southern African and American tectonic plates.  

When Gondwana began to  separate this ancestor was represented on both plates and evolved along the lines identified by the taxonomists. EXCEPT for the coconut which literally fell into the crack!

Of course, that would not have been the first time a palm fruit fell into water, floated and germinated. What makes this event special is that the gap between tectonic plates widened, so the coconut evolved by floating  the ever lengthening distance between them and in whatever direction was set by currents, tides or wind. Each and every generation would grow best under very similar conditions - high light intensity and tropical temperatures at sea level - which would minimise the need for more than one species to evolve. Since every beach could become both sender and receiver, which was "home" isn't important.

In contrast, the progenies of the  general purpose ancestor that remained on either of the tectonic plates had "homes" that got cooler and drier or hotter and wetter as ice ages came and went, or were uplifted to montane climates or sunk into swamps by geological processes. Genera and species that evolved in response to those stimuli might have features similar to coconut, inherited from that general purpose ancestor by chance, rather than by design, and not due to any common home.

I don't know if that will help you with your transgenic studies but you could ask a colleague I used to work with in Mexico:

José Juan Zúñiga Aguilar Unidad de Bioquímica y Biología Molecular de Plantas Centro de Investigaciòn Cientìfica de Yucatàn, Merida, Mexico Teléfono: (52)-(999)-942- 83- 30 Extensión: 246 Dirección de correo electrónico: zun...@cicy.mx

Good luck

Hugh