Molecular differentiation, diversity, and folk classification of “sweet” and “bitter” cassava (Manihot esculenta) in Caiçara and Caboclo management systems (Brazil)

Abstract

This study focuses the inter-relationships among the men, the use, and the intraspecific cassava diversity, under the perspective of this crop evolutionary dynamics. The origin, the use and the current local management of varieties with high and low cyanogenic potential are important questions around cassava domestication. We collected 169 local varieties identified as ''sweet'' or ''bitter'' cassava by traditional farmers from Atlantic Forest and Amazon (Medium Negro River Basin), Brazil. Using a population genetics and an ethnobotany approach, the diversity and the genetic structure of cassava were evaluated. We found a total of 115 vernacular names, and in the Atlantic Forest sample the average genetic diversity (H S = 0.654) was higher for the sweet varieties than for bitter ones (0.582). The genetic differentiation coefficient (R ST ), used to estimate the diversity among groups, was 0.057 (P < 0.001), indicating that the divergence between the two groups is low. We obtained a low correlation between the morphological and genetic distances, and the congruence was high when the ethnoclassification and the genetic structure were considered. We discuss the adaptive advantages of the sweet varieties use, the current socio-economic changes in bitter varieties use, and the ecological history of these variety groups.

Origin and Domestication of Native Amazonian Crops

“…If so, smallholders can either incorporate the seedlings into an existing variety or use them to establish a new variety [25,29,31,36,37]. Genetic analyses confirmed seedling incorporation by detecting high polymorphism in local varieties [24,31,36,38], and by demonstrating that local varieties are polyclonal, with one predominant clone and a set of morphologically similar plants that are genetically different [30,34,39].…”

Avanços nas pesquisas etnobotânicas no Brasil

“…As demais publicações trazem contribuições teóricas e metodológicas para a área e/ou abordam diversos aspectos das relações entre pessoas e plantas incluindo investigações sobre: conhecimento, uso e manejo de recursos vegetais em geral, significado cultural, origem e fluxo do conhecimento, etnotaxonomia e perda de conhecimento (Elisabetsky & Wannmacher 1993;Figueiredo et al 1993;Gottlieb & Borin 1995;Begossi 1996;Hanazaki et al 1996;Nunes & Imamura 1996;Albuquerque 1997;Figueiredo et al 1997;Second et al 1997;Albuquerque & Andrade 1998;Jardim & Cunha 1998;Albuquerque 1999;Gottlieb et al 1999;Rossato et al 1999;Allem 2000;Begossi et al 2000;Guarim Neto et al 2000;Hanazaki et al 2000;Peroni & Martins 2000;Gottlieb et al 2001;Marimon & Felfili 2001;Sambatti et al 2001 Botrel et al 2006;Chaves & Reinhard 2006;Costa et al 2006;Cunha & Albuquerque 2006;Ferraz et al 2006;Hanazaki et al 2006;Rodrigues 2006;Baraloto et al 2007;Florentino et al 2007;Lucena et al 2007;Miranda et al 2007;Peroni et al 2007;Schmidt et al 2007).…”

Ensiled Cassava (Manihot esculenta) Peel and Caged Layers’ Manure Mixture as Energy Source in Cockerel Starter Diet

“…Hydrogen cyanide concentrations depend on cultivar, environmental conditions, plant age, number of harvest (for the foliage) and on the plant component that is being considered. There is a continuous gradient of HCN content between varieties [9], which are usually divided into two groups:…”