Origin and Dispersal of Domesticated Peach Palm

Abstract

Peach palm (Bactris gasipaes Kunth) is a Neotropical palm domesticated by Native Americans. Its domestication resulted in a set of landraces (var. gasipaes), some with very starchy fruit used for fermentation, others with an equilibrium of starch and oil used as snacks. Which of the three wild types (var. chichagui) was involved and where the domestication process began are unclear, with three hypotheses under discussion: an origin in southwestern Amazonia; or in northwestern South America; or multiple origins. We reevaluate one of the wild types, defining it as the incipient domesticate, and then evaluate these hypotheses using the Brazilian peach palm Core Collection and selected herbaria samples to: (1) model the potential distributions of wild and domesticated populations; (2) identify the probable origin of domestication with a phylogeographic analysis of chloroplast DNA sequences; and (3) determine the dispersal routes after domestication using spatial analysis of genetic diversity based on 17 nuclear microsatellite loci. The two very small-fruited wild types have distinct distributions in the northern Andes region and across southern Amazonia, both under moderately humid climates, while the incipient domesticate, partly sympatric with the southern wild type, is also found along the Equatorial Andes, in a more humid climatic envelope, more similar to that of the domesticated landraces. Two distribution models for Last Glacial Maximum conditions (CCSM4, MIROC) also suggest distinct distributions for the two wild populations. The chloroplast DNA phylogeographic network confirms the area of sympatry of the incipient domesticate and the southern wild type in southwestern Amazonia as the origin of domestication. The spatial patterns of genetic diversity confirm the proposal of two dispersals, one along the Ucayali River, into western Amazonia, northwestern South America and finally Central America; the other along the Madeira River into central and then eastern Amazonia. The first dispersal resulted in very starchy fruit for fermentation, while the second may have been later and resulted in snack fruits. Further explorations of southwestern Amazonia are essential for more precise identification of the earliest events, both with new archeological methods and genetic analyses with larger samples.

A population genomics appraisal suggests independent dispersals for bitter and sweet manioc in Brazilian Amazonia

“…Bitter manioc along the Solimões River also was well‐dispersed, suggesting that this river may have been a centre of diversity during the early dispersals of bitter manioc, or much later because of its importance during the “rubber boom” (Neves, ). The Madeira River was also important for the dispersal of peach palm ( Bactris gasipaes ) from south‐western Amazonia into central and then eastern Amazonia (Clement et al, ). Treegourds ( Crescentia cujete ) were probably introduced into Amazonia through the upper Negro and Solimões Rivers (Moreira et al, ).…”

Phylogeography of the palm Syagrus coronata (Martius) Beccari (Arecaceae): distribution in the “Caatinga” and Atlantic forest domains

“…However, the Atlantic forest domain contains more haplotypes, and therefore, we suggest that the Atlantic forest domain is the center of diversity of S. coronata. The inverted-type sequence was observed in peach palm (Bactris gasipaes Kunth) in chloroplast intergenic spacers psbJ-petA, which distinguishes populations of peach palm (Clement et al 2017), suggesting that the inverted sequences may be utilized as parallel markers.…”

Exaptation Traits for Megafaunal Mutualisms as a Factor in Plant Domestication

“…Recent research into the domestication of peach palms ( Bactris gasipaes ) in South America has identified a heterogeneous mosaic of wild relatives, which appear to have played varying roles in the domestication process (Clement et al, 2017 ). Clement et al (2017:149) note that “dispersal by humans is effective for crossing barriers” and shifting distributions of Late Glacial Maximum populations of the palms are a key aspect of domestication.…”