Growth and Genetic Analysis of Pejibaye (Bactris Gasipaes Kunth, Palmae)in Hawai'i

Pejibaye or peach palm {Bactris gasipaes, Kunth) was introduced into Hawai’i to supply the gourmet market with fresh heart of palm. New crop introduction requires evaluation of crop adaptation to its new environment and planning for future development, including genetic improvement. Leaf number of open-pollinated Benjamin Constant (Putumayo landrace) progenies was lower at harvest (6-8) than elsewhere (8- 10), and offshoot number dropped dramatically from first harvest (6.5) to second harvest (2). Allometric equations for estimating whole plant leaf area and biomass were developed, using height and leaf number predictors. No significant plant population (density) effects on individual plant dimensions or growth were found over the range of 3333 to 6666 plants/ha. Relative growth rate (RGR) and unit leaf rate (E ^ between nursery and first harvest were highly correlated (r = -0.99 and -0.95, respectively) with earliness (days to harvest). The early progenies partitioned photoassimilates differently; two had high E^, while one had moderate E^ and partitioned preferentially to leaf area, resulting in a higher leaf area ratio. Heart of palm yields were close to 900 kg/ha after 12 months of harvest and 1400 kg/ha after 18 months, both comparable to tropical American yields. When edible stem and leaf were added to the yields, these increased to 2.8 and 4.5 t/ha of marketable product, respectively. Quantitative genetic analysis of growth parameters suggested high levels of inbreeding in the germplasm studied, since the narrow-sense heritabilities were double those observed in other perennials. Additive genetic variances for RGR and earliness suggested the potential for significant response to selection, but phenotypic variation varied depending on the interval over which RGR was estimated. The lowest estimate of RGR (over an entire development phase) provided the smallest response to selection but is similar to the response observed in other crops. Allozyme heterozygosity was remarkably low, ranging from 0.038 to 0.099, with a mean of 0.074, on par with inbred crops, rather than outbreeders. There was a lack of correlation between allozyme heterozygosity and growth parameters and morphological traits

Domestication and Dispersal of Native Crops in Amazonia

Recent decades have witnessed the rapid expansion of interest in and research on the domestication of crop plants worldwide. These species are the basis of the rise to dominance of Homo sapiens over the last 10,000 years. New techniques in archaeology and the expansion of molecular genetics are uncovering abundant evidence to support or refute old hypotheses about human domestication of crops and creation of food production systems that fueled population expansions and linguistic diasporas, and to raise new hypotheses. In Amazonia and elsewhere in lowland South America, archaeologists are starting to examine these hypotheses in earnest, and geneticists are starting to generate data to identify crop origins and dispersals. Archaeologists now generally agree that Amazonia was inhabited by numerous advanced societies before European conquest, especially along the major white water rivers and in other favorable locations for food production, and that these societies had domesticated significant areas of numerous landscapes. This special section of Tipití summarizes a set of presentations given during the recent 2nd International Meeting on Amazonian Archaeology, held in Manaus, Amazonas, in September 2010. An overview of plant domestication opens the sequence, followed by new archaeobotanical evidence from the southeastern Colombian and central Brazilian Amazonia and from the southern savannas of Brazil, and new molecular genetic evidence about the origins of peach palm (Bactris gasipaes) and the dispersal of manioc (Manihot esculenta), maize (Zea mays), and peach palm in lowland South America

Genetic Diversity and Differentiation of Brazilian Bitter and Sweet Manioc Varieties (Manihot esculenta Crantz, Euphorbiaceae) Based on SSR Molecular Markers

Manioc (Manihot esculenta Crantz) originated in Amazonia and is the main staple for more than 800 million people worldwide; it also had a fundamental role as a source of calories for many pre-Columbian peoples, especially in Amazonia, where it was domesticated. There are two major groups of manioc varieties: sweet varieties have low amounts of toxic substances (cyanogenic glycosides) and may be consumed with minimum processing, while bitter varieties have a high degree of toxicity and must be detoxified to be safe before consumption. These groups are outcomes of divergent selective pressures. Natural selection probably maintains large amounts of cyanogenic glycosides to serve as a plant defense when in cultivation. Human selection may reduce the toxicity of the plants when roots are directly consumed, but may be neutral when the roots are consumed after some kind of processing. Although farmers recognize the distinction of the two groups of varieties, the variation of cyanogenic glycosides is continuous among different varieties. Genetic differentiation between sweet and bitter varieties was detected with molecular markers, as well as different patterns of groupings of varieties from different regions of Brazil. The genetic distinctions suggest that the sweet varieties originated during the initial domestication in southwestern Amazonia and bitter varieties arose later during cultivation in Amazonia, as hypothesized by Arroyo-Kalin in a recent paper. They also suggest that these groups of varieties were dispersed independently, even though they are cultivated complementarily today, with sweet varieties in home-gardens and bitter varieties in swiddens

Observações sobre autocompatibilidade em pupunha (Bactris gasipaes H.B.K., Palmae)

A pupunha aparentemente, possui duas estratégias que asseguram a sua polinização cruzada. Uma delas parece ser um fator genético quantitativo que inibe a auto-polinização. Para estudar este fator, duas series de polinização controlada foram feitas em duas diferentes populações juvenis. A primeira população apresentou uma media, de 19,2% de auto-compatibilidade, medida em percentagem de frutos férteis produzidos em relação a todas as flores. Entretanto, o coeficiente de variação foi extremamente alto. A polinização aberta em algumas plantas produziu 22% de frutos férteis, com um coeficiente de variação menor, sugerindo que, o " fruit set" foi, em geral, baixo nutria população, naquela vez. A segunda população, apresentou em media 37,62% de auto-compatibilidade, com um coeficiente de variação menor. Variação entre as árvores foi também detectada e mostrou ser considerável. Além do mais, a auto-compatibilidade variou de 0 a 81%, em distribuição normal. 0 uso de plantas juvenis pode ser a razão da alta variabilidade entre plantas. Apesar da pouca auto-compatibilidade encontrada nestas populações, esta característica é recomendada como descritor para bancos de germoplasma e deve ser obtida em plantas adultas para evitar a alta variabilidade juvenil

Domestication of Peach Palm in Southwestern Amazonia

The peach palm (Bactris gasipaes Kunth) is the only Neotropical palm domesticated by Native Americans. Its place of origin as a crop (B. gasipaes var. gasipaes) has been debated for more than a century, with three hypotheses currently in discussion: southwestern Amazonia; northwestern South America; or multiple origins in the distribution of the wild relatives (B. gasipaes var. chichagui). The small amount of archaeological data available supports the second hypothesis, but they contrast dramatically with the molecular-genetic analyses that support the first or the third, depending on how they are interpreted. On morphological grounds, two of the three types of var. chichagui are plausible candidates for wild ancestral populations. All the molecular-genetic analyses have identified a deep division between the landraces of cultivated peach palm in western Amazonia to Central America and those in southwestern to eastern Amazonia. The first analysis using isoenzymes linked the Tembe population (Bolivia) with the Pará landrace (eastern Amazonia), and these were distant from the western landraces. Multiple RAPD and SSR analyses identified the same deep division, which was interpreted by the group of researchers in Brazil as a single domestication in southwestern Amazonia with two dispersals, while another group working in Costa Rica interpreted it as three domestication events. Analysis with nuclear markers does not allow discrimination among the hypotheses, because gene flow may occur via pollen and seed. A new analysis with two sequences from the chloroplast genome, which has maternal inheritance and is therefore more appropriate to test the hypothesis, suggests that the cultivated peach palm was domesticated once in southwestern Amazonia, with two dispersals. One dispersal started in the upper Ucayali River basin, in southeastern Peru, and then throughout western Amazonia, northwestern South America and southern Central America. Another dispersal started in the upper Madeira River basin and then along the Madeira River into eastern Amazonia. New explorations in southwestern Amazonia are critical to identify the exact location of the original events

Uso de AFLPS para discriminar raças primitivas de pupunha (Bactris gasipaes) na Amazônia brasileira

Although the first inhabitants of western Amazonia domesticated pejibaye (Bactris gasipaes Kunth, Palmae) or peach palm for its fruits, today it is widely planted for its heart-of-palm. Like other domesticates, pejibaye presents a complex hierarchy of landraces developed before the conquest of the Americas. The existence of three landraces (Pará, Solimões, Putumayo) was proposed along the Amazonas and Solimões Rivers, Brazil, based on morphological characteristics. There are some questions remaining about the intermediate landrace being an artifact of the morphometric analysis. AFLPs were used to evaluate the relationships among samples of these putative landraces. DNA was extracted from 99 plants representing 13 populations maintained in the Pejibaye Germplasm Bank, Manaus, AM; six primer combinations generated 245 markers via PCR, which were scored in an ABI Prism 310 sequencer and analyzed with GeneScan Software; Jaccard similarities were estimated and a dendrogram was generated with UPGMA. Two groups of plants were observed in the dendrogram instead of three, and were similar at 0.795. Each group contained two subgroups, similar at 0.815. One group (n=41) contained 73% Pará landrace plants, with one subgroup (n=22) containing 91% Pará, and the other (n=19) containing 53% Pará. The other group (n=58) contained 53% Solimões and 40% Putumayo landrace plants, with one subgroup (n=21) containing 52% Solimões and 43% Putumayo, and the other (n=35) containing 57% Solimões and 37% Putumayo. The first group confirmed the Pará landrace. The second group suggested that the Solimões landrace does not exist, but that the Putumayo landrace extends along the Solimões River to Central Amazonia.Os primeiros povos da Amazônia ocidental domesticaram a pupunha (Bactris gasipaes Kunth, Palmae) por seu fruto, embora hoje seja muito plantada por seu palmito. Como outros cultivos domesticados, a pupunha apresenta uma hierarquia complexa de raças primitivas criadas antes da conquista das Américas. A existência de três raças (Pará, Solimões, Putumayo) foi proposta ao longo dos rios Amazonas e Solimões, Brasil, com base em características morfológicas. Algumas dúvidas existem sobre a raça intermediária, pois podia ser um artefato da análise morfométrica. AFLPs foram usados para avaliar as relações entre amostras destas raças hipotéticas. DNA foi extraido de 99 plantas representando 13 populações mantidas no Banco de Germoplasma de Pupunha, Manaus, AM; seis combinações de 'primers' geraram 245 marcadores via PCR, que foram codificados num sequenciador ABI Prism 310 e analisados com o programa GeneScan; similaridades de Jaccard foram estimadas e um dendrograma foi criado com UPGMA. Dois grupos de plantas foram observados no dendrograma, em lugar de três, com similaridade de 0,795. Cada grupo continha dois subgrupos, similares a 0,815. Um grupo (n=41) continha 73% de plantas da raça Pará, com um subgrupo (n=22) contendo 91% Pará e o outro (n=19) contendo 53% Pará. O outro grupo (n=58) continha 53% de plantas da raça Solimões e 40% da Putumayo, com um subgrupo (n=21) contendo 52% Solimões e 43% Putumayo, e o outro (n=35) contendo 57% Solimões e 37% Putumayo. O primeiro grupo confirmou a raça Pará, mas o segundo grupo sugeriu que a raça Solimões não existe; em lugar desta raça, a raça Putumayo se extende ao longo do rio Solimões até a Amazônia Central

Pre-Columbian soil fertilization and current management maintain food resource availability in old-growth Amazonian forests

Aims: The extent and persistence of pre-Columbian human legacies in old-growth Amazonian forests are still controversial, partly because modern societies re-occupied old settlements, challenging the distinction between pre- and post-Columbian legacies. Here, we compared the effects of pre-Columbian vs. recent landscape domestication processes on soils and vegetation in two Amazonian regions. Methods: We studied forest landscapes at varying distances from pre-Columbian and current settlements inside protected areas occupied by traditional and indigenous peoples in the lower Tapajós and the upper-middle Madeira river basins. By conducting 69 free-listing interviews, participatory mappings, guided-tours, 27 forest inventories, and soil analysis, we assessed the influences of pre-Columbian and current activities in soils and plant resources surrounding the settlements. Results: In both regions, we found that pre-Columbian villages were more densely distributed across the landscape than current villages. Soil nutrients (mainly Ca and P) were higher closer to pre-Columbian villages but were generally not related to current villages, suggesting past soil fertilization. Soil charcoal was frequent in all forests, suggesting frequent fire events. The density of domesticated plants used for food increased in phosphorus enriched soils. In contrast, the density of plants used for construction decreased near current villages. Conclusions: We detected a significant effect of past soil fertilization on food resources over extensive areas, supporting the hypothesis that pre-Columbian landscape domestication left persistent marks on Amazonian landscapes. Our results suggest that a combination of pre-Columbian phosphorus fertilization with past and current management drives plant resource availability in old-growth forests.</p

Conservation implications of the mating system of the Pampa Hermosa landrace of peach palm analyzed with microsatellite markers

Peach palm (Bactris gasipaes) is cultivated by many indigenous and traditional communities from Amazonia to Central America for its edible fruits, and is currently important for its heart-of-palm. The objective of this study was to investigate the mating system of peach palm, as this is important for conservation and breeding. Eight microsatellite loci were used to genotype 24 open-pollinated progenies from three populations of the Pampa Hermosa landrace maintained in a progeny trial for genetic improvement. Both the multi-locus outcrossing rates (0.95 to 0.99) and the progeny level multi-locus outcrossing rates (0.9 to 1.0) were high, indicating that peach palm is predominantly allogamous. The outcrossing rates among relatives were significantly different from zero (0.101 to 0.202), providing evidence for considerable biparental inbreeding within populations, probably due to farmers planting seeds of a small number of open-pollinated progenies in the same plot. The correlations of paternity estimates were low (0.051 to 0.112), suggesting a large number of pollen sources (9 to 20) participating in pollination of individual fruit bunches. Effective population size estimates suggest that current germplasm collections are insufficient for long-term ex situ conservation. As with most underutilized crops, on farm conservation is the most important component of an integrated conservation strategy

Bostonia: The Boston University Alumni Magazine. Volume 12

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