Maize dispersal patterns associated with different types of endosperm and migration of indigenous groups in lowland South America

Abstract

Background and Aims The lowlands of South America appear to be remarkably important in the evolutionary history of maize, due to new evidence that suggests that maize dispersed from Mexico and arrived in this region in a state of partial domestication. This study aimed to identify dispersal patterns of maize genetic diversity in this portion of the continent. Methods A total of 170 maize accessions were characterized with 4,398 single nucleotide polymorphisms (SNPs) and analyzed to determine if maize dispersal was associated with types of endosperm and indigenous language families. Key Results Four genetic groups were identified in the Discriminant Analysis of Principal Components (DAPC) and five groups in the cluster analysis (Neighbor-Joining method). The groups were structured according to the predominance of endosperm types (popcorn, floury, flint/semi-flint). Spatial Principal Component Analysis (sPCA) of genetic variation suggests different dispersal patterns for each endosperm type and can be associated with hypotheses of expansions of different indigenous groups. Conclusions From a possible origin in Southwestern Amazonia, different maize dispersal routes emerged: i) towards Northern Amazonia, which continued towards the Caatinga and southeastern Atlantic Forest (Floury); ii) towards Southern Brazil, passing through the Cerrado, Southern Atlantic Forest reaching the Pampa region (Floury); and iii) along the Atlantic Coast, following Tupi movements originating from two separate expansions: one (Tupinamba) expanded from North to South, and the other (Guarani) in the opposite direction, from South to North (Flint, Floury and Popcorn).

Chemical analysis of pottery reveals the transition from a maritime to a plant-based economy in pre-colonial coastal Brazil

“…We know, for example, that political alliances and social status were closely related to feasting and the preparation of Cauim 11 , 12 . In turn, the Guarani diaspora was of importance to the genetic and geographic variation of maize in South America 17 . Indeed, the longer-term consequences of the Guarani expansion, which eventually encompassed the entire coast of Brazil, are potentially profound.…”

“…Modern genetic and linguistic evidence suggests a strong connection between the dispersal of maize and the expansion of pre-colonial groups including the Macro-Jê and Tupi-Guarani language families, most recently at ca. 700 cal BP 17 , 18 . The Guarani expansion territory (Fig.…”

“…The Guarani expansion territory (Fig. 1 ) along the South Brazilian coast seems especially connected to the spread of popcorn maize, which has high diversity in Santa Catarina 17 , 19 . Nonetheless, direct evidence for the antiquity and consumption of maize in pre-colonial Southeastern Brazil is severely limited to occasional finds of microfossils (i.e.…”

Diversity of vegetable landraces in the Pampa biome of Brazil and Uruguay: utilization and conservation strategies

“…Landraces of 49 vegetable crops belonging to 47 species and 11 botanical families (excluding aromatic herbs) are currently cultivated in the Brazilian-Uruguayan Pampa biome (Table 1), as reported by Antunes et al (2015); Barbieri et al (2014); Cruz (2022); Fischer (2012); Fischer et al (2016); Neitzke et al (2015); Padilha (2017); Priori et al (2022);. Priori et al (2018); Priori et al (2017); Burgueño et al (2015); Pereira (2017); Mello et al (2017); Favaro and Piazza (2019) and Cuadro (2022).…”

“…For the more in-depth territorial surveys carried out by Pereira in 'Rocha' (2017), Favaro and Piazza in 'Canelones' (2019) and Cuadro in 'Maldonado' (2022) in Uruguay, 43 vegetable crops (40 species) belonging to 10 plant families and 426 landraces (cassava was notrecorded in these territories). Plant families more commonly found were Fabaceae, Cucurbitaceae and Brassicaceae, whereas the largest number of landraces corresponded to Cucurbitaceae (83), Fabaceae (71) and Solanaceae (60) (Table 2).…”