Larry R. Noblick

Correction: Phylogenetic Analysis of Seven WRKY Genes across the Palm Subtribe Attaleinae (Arecaceae) Identifies Syagrus as Sister Group of the Coconut

Background The Cocoseae is one of 13 tribes of Arecaceae subfam. Arecoideae, and contains a number of palms with significant economic importance, including the monotypic and pantropical Cocos nucifera L., the coconut, the origins of which have been one of the “abominable mysteries” of palm systematics for decades. Previous studies with predominantly plastid genes weakly supported American ancestry for the coconut but ambiguous sister relationships. In this paper, we use multiple single copy nuclear loci to address the phylogeny of the Cocoseae subtribe Attaleinae, and resolve the closest extant relative of the coconut. Methodology/Principal Findings We present the results of combined analysis of DNA sequences of seven WRKY transcription factor loci across 72 samples of Arecaceae tribe Cocoseae subtribe Attaleinae, representing all genera classified within the subtribe, and three outgroup taxa with maximum parsimony, maximum likelihood, and Bayesian approaches, producing highly congruent and well-resolved trees that robustly identify the genus Syagrus as sister to Cocos and resolve novel and well-supported relationships among the other genera of the Attaleinae. We also address incongruence among the gene trees with gene tree reconciliation analysis, and assign estimated ages to the nodes of our tree. Conclusions/Significance This study represents the as yet most extensive phylogenetic analyses of Cocoseae subtribe Attaleinae. We present a well-resolved and supported phylogeny of the subtribe that robustly indicates a sister relationship between Cocos and Syagrus. This is not only of biogeographic interest, but will also open fruitful avenues of inquiry regarding evolution of functional genes useful for crop improvement. Establishment of two major clades of American Attaleinae occurred in the Oligocene (ca. 37 MYBP) in Eastern Brazil. The divergence of Cocos from Syagrus is estimated at 35 MYBP. The biogeographic and morphological congruence that we see for clades resolved in the Attaleinae suggests that WRKY loci are informative markers for investigating the phylogenetic relationships of the palm family.

Phylogeny and historical biogeography of the cocosoid palms (Arecaceae, Arecoideae, Cocoseae) inferred from sequences of six WRKY gene family loci

Arecaceae tribe Cocoseae is the most economically important tribe of palms, including both coconut and African oil palm. It is mostly represented in the Neotropics, with one and two genera endemic to South Africa and Madagascar, respectively. Using primers for six single copy WRKY gene family loci, we amplified DNA from 96 samples representing all genera of the palm tribe Cocoseae as well as outgroup tribes Reinhardtieae and Roystoneae. We compared parsimony (MP), maximum likelihood (ML), and Bayesian (B) analysis of the supermatrix with three species‐tree estimation approaches. Subtribe Elaeidinae is sister to the Bactridinae in all analyses. Within subtribe Attaleinae, Lytocaryum, previously nested in Syagrus, is now positioned by MP and ML as sister to the former, with high support; B maintains Lytocaryum embedded within Syagrus. Both MP and ML resolve Cocos as sister to Syagrus; B positions Cocos as sister to Attalea. Bactridineae is composed of two sister clades, Bactris and Desmoncus in one, for which there is morphological support, and a second comprising Acrocomia, Astrocaryum, and Aiphanes. Two B and one ML gene tree‐species estimation approaches are incongruent with the supermatrix in a few critical intergeneric clades, but resolve the same infrageneric relationships. The biogeographic history of the Cocoseae is dominated by dispersal events. The tribe originated in the late Cretaceous in South America. Evaluated together, the supermatrix and species tree analyses presented in this paper provide the most accurate picture of the evolutionary history of the tribe to date, with more congruence than incongruence among the various methodologies.

Cyclone tolerance in new world arecaceae: biogeographic variation and abiotic natural selection.

BACKGROUND AND AIMS Consistent abiotic factors can affect directional selection; cyclones are abiotic phenomena with near-discrete geographic limits. The current study investigates selective pressure of cyclones on plants at the species level, testing for possible natural selection. METHODS New World Arecaceae (palms) are used as a model system, as plants with monopodial, unbranched arborescent form are most directly affected by the selective pressure of wind load. Living specimens of known provenance grown at a common site were affected by the same cyclone. Data on percentage mortality were compiled and analysed in biogeographic and phylogenetic contexts. KEY RESULTS Palms of cyclone-prone provenance exhibited a much lower (one order of magnitude) range in cyclone tolerance, and significantly lower (P < 0.001) mean percentage mortality than collections from cyclone-free areas. Palms of cyclone-free provenance had much greater variation in tolerance, and significantly greater mean percentage mortality. A test for serial independence recovered no significant phylogenetic autocorrelation of percentage mortality. CONCLUSIONS Variation in cyclone tolerance in New World Arecaceae correlates with biogeography, and is not confounded with phylogeny. These results suggest natural selection of cyclone tolerance in cyclone-prone areas.

Leaf anatomy of Acrocomia (Arecaceae): an additional contribution to the taxonomic resolution of a genus with great economic potential

Acrocomia is one of the most complex genera to understand in the Neotropical Arecaceae, and there is no consensus on the number of species in the genus. A comparative study of leaf anatomy was conducted on seven species of Acrocomia: one with a wide distribution in the Americas (A. aculeata), five endemic to different regions of Brazil, Bolivia and Paraguay (A. emensis, A. glaucescens, A. hassleri, A. intumescens and A. totai) and one endemic to Cuba (A. crispa). Characters that unify the species of Acrocomia include the following: epidermis covered with cuticle, hypodermis on both sides of the leaflets, non-vascular fiber bundles, and primary and secondary vascular bundles. The shape of the leaflet margin, the distribution of the primary vascular bundles and fiber bundles, the number of idioblasts with raphides and the size of the vascular bundles, along with other characteristics, were used to distinguish these species in Acrocomia.

Structural cladistic study of Cocoseae, subtribe Attaleinae (Arecaceae): Evaluating taxonomic limits in Attaleinae and the neotropical genus Syagrus

Syagrus (Areaceae: Cocoseae) is a New World palm genus occurring through most of South America, with one species in the eastern Caribbean. Relationships within Syagrus, Cocoseae and Attaleinae (Arecaceae) are investigated via cladistic analysis of 130 structural characters in 69 ingroup and three outgroup species. The data resolve relationships and test generic limits of Attaleinae and among the Syagrus complex. Maximum parsimony analysis derived the following relationships: 1) two major clades (butioid and syagroid) are resolved; 2) Syagrus is polyphyletic as presently defined, with Allagoptera (incl. Polyandrococos), Cocos, Voanioala, and Attalea nested within it; 3) all genera studied except Syagrus and Butia are monophyletic; and 4) relationships in Syagrus broadly align with phytogeography and leaflet anatomy. The data suggest that Syagrus is polyphyletic, and presently accepted taxonomy may not predict monophyletic groups. The relationships predicted by the structural data differ from those resolved via molecular means in part, and also show some congruence.