Genetic Structure and Pod Morphology of Inga edulis Cultivated vs. Wild Populations from the Peruvian Amazon

Abstract

Research Highlights: This study assesses the genetic diversity and structure of the ice-cream-bean (Inga edulis Mart.; Fabaceae) in wild and cultivated populations from the Peruvian Amazon. This research also highlights the importance of protecting the biodiversity of the forest in the Peruvian Amazon, to preserve the genetic resources of species and allow further genetic improvement. Background and Objectives: Ice-cream-bean is one of the most commonly used species in the Amazon region for its fruits and for shading protection of other species (e.g., cocoa and coffee plantations). Comprehensive studies about the impact of domestication on this species’ genetic diversity are needed, to find the best conservation and improvement strategies. Materials and Methods: In the current study, the genetic structure and diversity were assessed by genotyping 259 trees, sampled in five wild and 22 cultivated I. edulis populations in the Peruvian Amazon, with microsatellite markers. Pod length was measured in wild and cultivated trees. Results: The average pod length in cultivated trees was significantly higher than that in wild trees. The expected genetic diversity and the average number of alleles was higher in the wild compared to the cultivated populations; thus, a loss of genetic diversity was confirmed in the cultivated populations. The cultivated trees in the Loreto region had the highest pod length and lowest allelic richness; nevertheless, the wild populations’ genetic structure was not clearly differentiated (significantly different) from that of the cultivated populations. Conclusions: A loss of genetic diversity was confirmed in the cultivated populations. The species could have been simultaneously domesticated in multiple locations, usually from local origin. The original I. edulis Amazonian germplasm should be maintained. Cultivated populations’ new germplasm influx from wild populations should be undertaken to increase genetic diversity.

Preliminary Evidence for Domestication Effects on the Genetic Diversity of Guazuma crinita in the Peruvian Amazon

“…One may expect that trees sampled over a relatively small geographical range (as in our study) would show low levels of variation among populations [15]. However, in some studies in the tropics, trees were sampled over extensive geographical ranges and still showed low differentiation among population (e.g., Swietenia macrophylla King [52]; Vitellaria paradoxa Gaertn [53]; Inga edulis Mart [22]).…”

“…The sample size in this study was small so we consider the results as preliminary. Other studies of genetic diversity in tropical tree species have also used small sample sizes [17,[19][20][21][22] and reported genetic diversity patterns consistent with studies based on large sample sizes.…”

Edible Fruits from the Ecuadorian Amazon: Ethnobotany, Physicochemical Characteristics, and Bioactive Components

“…Considering the characteristics and properties of native Amazonian fruits, it is crucial to expand research on their nutraceutical functions and the domestication process of these species, which begins with the exploitation of wild plants, continues with the cultivation of plants selected by nature, and ends with the fixation of morphological and genetic characteristics through human selection. This will allow for the establishment of appropriate strategies for using genetic resources, as well as for the conservation and extraction of non-timber resources [125,126].…”

Can seed exchange networks explain the morphological and genetic diversity in perennial crop species? The case of the tropical fruit tree Dacryodes edulis in rural and urban Cameroon

“…The effects of cultivation on intraspecific plant diversity are generally demonstrated by comparative studies of wild against cultivated populations. For native perennial species in the tropics, fruits from cultivated populations are often shown to be significantly larger than those from wild stands, although the two population types are not necessarily clearly genetically differentiated (Aguirre‐Dugua et al, 2012; Moreira et al, 2017; Rollo et al, 2020). This comparative framework can be complexified, with sampling being carried out from wild populations to more or less intensively managed environments, such as agroforestry systems and monocultures.…”