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1.
Manioc is the most important food crop that originated in Amazonia. Many studies have increased our understanding of its evolutionary dynamics under cultivation. However, most of them focused on manioc cultivation in environments with low soil fertility, generally Oxisols. Recent ethnobotanical observations showed that bitter manioc also performs well in high fertility soils, such as Amazonian dark earths (ADE) and the floodplain. We used 10 microsatellite loci to investigate the genetic diversity and structure of bitter manioc varieties grown in different soil types in communities of smallholder farmers along the middle Madeira River in Central Amazonia. The genetic diversity of some sweet varieties and seedlings was also evaluated. Adult individuals showed higher levels of genetic diversity and smaller inbreeding coefficients (A ( R ) = 5.52, H ( O ) = 0.576, f = 0.086) than seedlings (A ( R ) = 4.39, H ( O ) = 0.421, f = 0.242). Bitter manioc varieties from the floodplain showed higher levels of genetic diversity (A ( R ) = 5.19, H ( O ) = 0.606) than those from ADE (A ( R ) = 4.45, H ( O ) = 0.538) and from Oxisols (A ( R ) = 4.15, H ( O ) = 0.559). The varieties grown in the floodplain were strongly differentiated from the varieties grown in Oxisols (F ( ST ) = 0.093) and ADE (F ( ST ) = 0.108), suggesting important genetic structuring among varieties grown in the floodplain and upland soils (ADE and Oxisols). This is the first time that genetic divergence of bitter manioc varieties in cultivation in different Amazonian soils in a small geographic area is reported. 相似文献
2.
Convergent adaptations: bitter manioc cultivation systems in fertile anthropogenic dark earths and floodplain soils in central amazonia 总被引:1,自引:0,他引:1
SHIFTING CULTIVATION IN THE HUMID TROPICS IS INCREDIBLY DIVERSE, YET RESEARCH TENDS TO FOCUS ON ONE TYPE: long-fallow shifting cultivation. While it is a typical adaptation to the highly-weathered nutrient-poor soils of the Amazonian terra firme, fertile environments in the region offer opportunities for agricultural intensification. We hypothesized that Amazonian people have developed divergent bitter manioc cultivation systems as adaptations to the properties of different soils. We compared bitter manioc cultivation in two nutrient-rich and two nutrient-poor soils, along the middle Madeira River in Central Amazonia. We interviewed 249 farmers in 6 localities, sampled their manioc fields, and carried out genetic analysis of bitter manioc landraces. While cultivation in the two richer soils at different localities was characterized by fast-maturing, low-starch manioc landraces, with shorter cropping periods and shorter fallows, the predominant manioc landraces in these soils were generally not genetically similar. Rather, predominant landraces in each of these two fertile soils have emerged from separate selective trajectories which produced landraces that converged for fast-maturing low-starch traits adapted to intensified swidden systems in fertile soils. This contrasts with the more extensive cultivation systems found in the two poorer soils at different localities, characterized by the prevalence of slow-maturing high-starch landraces, longer cropping periods and longer fallows, typical of previous studies. Farmers plant different assemblages of bitter manioc landraces in different soils and the most popular landraces were shown to exhibit significantly different yields when planted in different soils. Farmers have selected different sets of landraces with different perceived agronomic characteristics, along with different fallow lengths, as adaptations to the specific properties of each agroecological micro-environment. These findings open up new avenues for research and debate concerning the origins, evolution, history and contemporary cultivation of bitter manioc in Amazonia and beyond. 相似文献
3.
Useful Species Richness, Proportion of Exotic Species, and Market Orientation on Amazonian Dark Earths and Oxisols Anthropogenic soils of Amazonia, known as Amazonian Dark Earths (ADE), are environments with elevated soil fertility that
can produce crops that otherwise yield poorly on the leached and highly acidic Oxisols that dominate much of the basin. While
ADE sites near urban centers often attract commercial horticultural production of nutrient–demanding exotics, these soils
are also considered possibly unique reservoirs of endemic agrobiodiversity because of their relationship to pre–Columbian
indigenous occupation. Through botanical surveys and interviews with smallholder farmers, this study compared useful species
richness, proportion of exotic species, and market orientation of farms situated on ADE and non–anthropogenic Oxisols in the
municipality of Borba in Central Brazilian Amazonia. Species richness was similar on Amazonian Dark Earth and Oxisol farms
(19.6 spp vs. 18.3 spp); however, ADE farms showed significantly higher proportions of exotic species (39% vs. 26%; p = 0.025). Furthermore, ADE farms in Borba demonstrated significantly higher market orientation (61.0% vs. 47.3%; p = 0.028), likely a result of the advantage of Amazonian Dark Earths for production of crops that are nutrient–demanding or
pH–sensitive crops that have higher values in the nearby regional market of Manaus. 相似文献
4.
James Angus Fraser André B. Junqueira Nicholas C. Kawa Claide P. Moraes Charles R. Clement 《Human ecology: an interdisciplinary journal》2011,39(4):395-406
A recent archaeological survey demonstrates that one of the most durable of all forms of pre-Columbian landscape transformation,
Amazonian Dark Earths (ADE; soils formed by pre-Columbian settlement), are widespread along the course of the Madeira River,
Central Amazonia, Brazil. We hypothesize that processes of crop cultivation and management by human populations today in landscapes
that were intensively transformed during the pre-Columbian period will diverge from those in environments where human agency
has not left such a heavy footprint. In order to test this hypothesis, we compare bitter manioc fields, homegardens and secondary
forests on ADE with those on non-anthropogenic soils along the lower and middle Madeira River. We demonstrate that crop species
and landrace populations diverge on anthropogenic and non-anthropogenic soils as a result of the interaction between human
selection and management, soil physical and chemical properties, and plant responses over time. Hence, crop species selection
and abundance and therefore agrobiodiversity is contingent on anthropogenic soils in Central Amazonia. 相似文献
5.
“Made in Brazil”: Human Dispersal of the Brazil Nut (
Bertholletia excelsa
, Lecythidaceae) in Ancient Amazonia. The Brazil nut, Bertholletia excelsa, is a colossal tree of terra firme forest whose seeds represent the most important non-timber forest product in Amazonia. Its peculiarly inefficient dispersal
strategy and discontinuous distribution have led some to hypothesize anthropogenic origins, but evidence to date has been
inconclusive. Here we present results of a multidisciplinary study addressing this question. A review of the geographic distribution
of B. excelsa and comparison with that of similar Lecythis species suggest a number of anomalies that are consistent with a recent and wide colonization of Bertholletia. Published studies and field observations indicate that anthropogenic disturbance facilitates Brazil nut regeneration. Recent
genetic studies showing no sequence diversity and no geographical structuring of within-population variability support a rapid
and recent irradiation from an ancestral population. Historical linguistic analysis of indigenous terms for Brazil nut suggests
a northern/eastern Amazonian origin for Bertholletia, with a concomitant spread of Brazil nut distribution or cultivation to the south and west. Such an expansion would have
been particularly facilitated by the emergence of intensive bitter manioc cultivation and networks of interethnic trade beginning
in the first millennium C.E. Together, ecological, phytogeographic, genetic, linguistic, and archeological data reinforce
the hypothesis that ancient Amazonian peoples played a role in establishing this emblematic and economically important rainforest
landscape. 相似文献
6.
Jing Zhang Yan Liu Dan Yu Hongze Song Jingjin Cui Tao Liu 《Journal of applied phycology》2011,23(2):165-171
Hybridization of gametophytes, continuous self-crossing and targeted selection were utilized to breed a new Laminaria variety. After five-generation selection breeding, the new variety “Rongfu” was obtained. Its male parent “Yuanza No.10”
was the high-yield cultivation variety, and its female parent was variety “Fujian” which could tolerate relatively high seawater
temperature. “Yuanza No.10” and “Fujian” were different but complement in their morphological characteristics and biological
habits. Variety “Rongfu” was bred through their hybridization which exhibited high-yield potential and high seawater temperature
tolerance. The results of traits evaluation in consecutive years showed that “Rongfu” attained higher yields by 24–27% compared
to the control (widely used commercial variety) and also contained considerable amounts of iodine, mannitol, and algin. When
seawater temperature was 18–21°C, the blade growth of “Rongfu” was maintained and tissue loss by abrasion was significantly
lower than the control. Since the adoption of variety “Rongfu” in 2001, its cultivation areas have been extended to Shandong,
Fujian and Guangdong province and have reached 14,133 ha currently, i.e., almost one-tenth of the total cultivation areas
of Laminaria in China. The results of Random Amplified Polymorphic DNA analysis showed that the relationship between “Rongfu” and other
cultivation varieties in China was very close. 相似文献
7.
Homegardens on Amazonian Dark Earths, Non-anthropogenic Upland, and Floodplain Soils along the Brazilian Middle Madeira River
Exhibit Diverging Agrobiodiversity. We test the hypothesis that the agrobiodiversity associated with homegardens on three different soils—upland Amazonian Dark
Earths (ADE) and Oxisols (OX), and Fluvent Entisols (FL)—commonly found along the middle Madeira River in the municipality
of Manicoré, Amazonas State, Brazil, is different due to the contrasting biotic, abiotic, and cultural settings specific to
each of these soils. Using data from interviews with 63 farmers about food and utility species, we compare structural and
floristic characteristics of homegarden agrobiodiversity. The density of individuals is higher on ADE than on the other soils
(mean ± standard deviation: 715 ± 363 on ADE, 474 ± 283 on OX, 642 ± 399 on FL). ADE and OX have higher species richness (28.2 ± 5.6
on ADE, 25 ± 3.7on OX, 23.6 ± 5 on FL), while ADE and FL have a greater degree of domestication (2 ± 0.6 on ADE, 1.3 ± 0.5
on OX, 2.3 ± 0.6 on FL). ADE and OX have greater proportions of richness, density, and coverage composed of South American
species, while FL has greater proportions of richness and density composed of Old World species. ADE has higher proportions
of density and coverage of Mesoamerican species. Floristic composition is also different between soils: ADE occupies an intermediate
position, composed of species associated with each of the other soil types and species that are most common on ADE. These
differences in agrobiodiversity emerge through the interaction of human agency, plant responses, and the unique properties
of soils in relation to socioeconomic and historical trajectories over time. 相似文献
8.
Estela Quintero‐Vallejo Yannick Klomberg Frans Bongers Lourens Poorter Marisol Toledo Marielos Peña‐Claros 《Biotropica》2015,47(2):152-161
Amazonian Dark Earths (ADE) are the result of human modification of the Amazonian landscape since pre‐Columbian times. ADE are characterized by increased soil fertility compared to natural soils. In the Amazonian forest, soil fertility influences understory herb and fern species composition. However, little research has been done to evaluate the effect of ADE on the composition of the understory community. We evaluated the effects of ADE and soil in 36 plots (150 m × 4 m) established in a Bolivian moist forest (La Chonta). For each plot, we determined soil nutrients, and the composition, richness, and abundance of terrestrial fern, angiosperm herb, and understory palm species. We found that the presence of ADE created a gradient in soil nutrients and pH that affected the understory species composition especially of ferns and palms. Additionally, the higher nutrient concentration and more neutral soil pH on ADE soils caused a decrease of ferns species richness. We therefore conclude that the current composition of the understory community in this particular Bolivian forest is a reflection of past human modifications of the soil. 相似文献
9.
Karine Louise dos Santos Nivaldo Peroni Raymond Paul Guries Rubens Onofre Nodari 《Economic botany》2009,63(2):204-214
Traditional Knowledge and Management of
Feijoa (Acca sellowiana)
in Southern Brazil. This paper investigates traditional knowledge of the use and management of Acca sellowiana in southern Brazil. Fifty-six informants from three rural communities were assigned to one of four subgroups (“maintainers,”
“managers,” “cultivators,” or “users”) based on their responses regarding management and use of A. sellowiana. Traditional knowledge related to use of this species is widespread among rural residents, but traditional knowledge related
to management is fragmented depending on whether one uses, manages, or cultivates the species. Knowledge held in rural communities
suggests that A. sellowiana could play an expanded role in local economies as well as biodiversity conservation. We suggest that participatory research
could stimulate greater local use as well as on-farm conservation of A. sellowiana. 相似文献
10.
The redistribution of soil water by tree root systems 总被引:29,自引:0,他引:29
Plant roots transfer water between soil layers of different water potential thereby significantly affecting the distribution
and availability of water in the soil profile. We used a modification of the heat pulse method to measure sap flow in roots
of Grevillea robusta and Eucalyptus camaldulensis and demonstrated a redistribution of soil water from deeper in the profile to dry surface horizons by the root system. This
phenomenon, termed “hydraulic lift” has been reported previously. However, we also demonstrated that after the surface soils
were rewetted at the break of season, water was transported by roots from the surface to deeper soil horizons – the reverse
of the “hydraulic lift” behaviour described for other woody species. We suggest that “hydraulic redistribution” of water in
tree roots is significant in maintaining root viability, facilitating root growth in dry soils and modifying resource availability.
Received: 26 January 1998 / Accepted: 15 April 1998 相似文献
11.
C. P. Peña-Venegas T. J. Stomph G. Verschoor J. A. Echeverri P. C. Struik 《Human ecology: an interdisciplinary journal》2016,44(1):1-15
Outsiders often oversimplify Amazon soil use by assuming that abundantly available natural soils are poorly suited to agriculture and that sporadic anthropogenic soils are agriculturally productive. Local perceptions about the potentials and limitations of soils probably differ, but information on these perceptions is scarce. We therefore examined how four indigenous communities in the Middle Caquetá River region in the Colombian Amazon classify and use natural and anthropogenic soils. The study was framed in ethnopedology: local classifications, preferences, rankings, and soil uses were recorded through interviews and field observations. These communities recognized nine soils varying in suitability for agriculture. They identified anthropogenic soils as most suitable for agriculture, but only one group used them predominantly for their swiddens. As these communities did not perceive soil nutrient status as limiting, they did not base crop-site selection on soil fertility or on the interplay between soil quality and performance of manioc genetic resources. 相似文献
12.
Yingxin Huang Xueyong Zhao Hongxuan Zhang Wisdom Japhet Xiaoan Zuo Yayong Luo Gang Huang 《Journal of Plant Biology》2009,52(3):210-219
We monitored the allometric effects for greenhouse-grown Agriophyllum squarrosum plants in response to variations in population density and the availability of soil nutrients and water. Biomass allocations
were size-dependent. The plasticity of roots, stems, leaves, and reproductive effort was “true” in response to changes in
nutrient content. At a low level of soil minerals, plants allocated more resources to the development of roots and reproductive
organs than to leaves, but data for stem allocations were consistent for tradeoffs between the effects of nutrients and plant
size. The plasticities of leaf allocation and reproductive effort were “true” whereas those of root and stem allocations were
“apparent” in response to fluctuations in soil water, being a function of plant size. Decreasing soil water content was associated
with higher leaf allocation and lower reproductive effort. Except for this “apparent” plasticity of leaf allocation, none
was detected with population density on biomass allocation. Architectural traits were determinants of the latter. For roots,
the determining trait was the ratio of plant height to total biomass; for stems and reproduction, plant height; and for leaves,
the ratio of branch numbers to plant height. 相似文献
13.
Fossil species ofMelanopsis from a freshwater formation in the Jordan Valley (near Al-Qarn) were investigated and the deposits containing these species
are formally described as Al-Qarn Formation. Four species were found:Melanopsis buccinoidea
Olivier,M. tchernovi
Heller & Sivan,M. costata
Olivier andM. aaronsohni
Blanckenhorn.Melanopsis costata was represented by two groups, “stepped” and “non-stepped”, the latter differing in its lower figurativity index. Intermediates
were found betweenM. buccinoidea andM. tchernovi; they may be hybrids. TheMelanopsis assemblage bridges the faunal gap, in the Jordan Valley, between the 2 Ma lake of ‘Erq el Ahmar on the one hand and the 0.8–1.7
Ma lake of ‘Ubeidiya on the other. This suggests an early Pleistocene age of about 1.8 million years for the Al-Qarn Formation. 相似文献
14.
Walter W. Ferguson 《Primates; journal of primatology》1992,33(2):273-279
In response to a critique byFerguson (1989),Leonard (1991) reiterates most of his original arguments for supporting “Australopithecus afarensis”Johanson, White, andCoppens, 1978 as a single species. He disregards the principle of morphological equivalence by comparing the dental metrics and morphology
of a hominid with those of species of the Pongidae, which do not correspond with the degree of variation in hominids, instead
of with those of species of the Hominidae. He fails to refute clear evidence that the range of variation of dental metrics
and morphology in “A. afarensis” exceeds that seen in species of the Hominidae. On the basis of extreme variation, “A. afarensis” is, therefore, interpreted as representing a composite species. 相似文献
15.
Over two consecutive years in the North Bank Plain Zone of Assam, India, during the spring growing season (February–June)
of- 2006 and 2007 we examined effects of morpho-physiological characteristics of rice (Oryza sativa L.) plants in relation to methane (CH4) emission from paddy fields. Traditional cultivar “Agni” and modern improved cultivar “Ranjit” were grown in light textured
loamy soil under irrigation. A higher seasonal integrated methane flux (E
sif) was recorded from “Agni” compared to “Ranjit”. Both cultivars exhibited an emission peak during active vegetative growth
and a second peak at panicle initiation. Leaf and tiller number, leaf area, length, and volume of root were greater in “Agni”,
but grain yield and yield-related parameters such as increased photosynthate partitioning to panicles at the expense of roots
were greater in “Ranjit”. “Ranjit” also photosynthesed faster than “Agni” during panicle development but slower than “Agni”
at tillering. In both the years, a higher soil organic carbon content was recorded in plots of “Agni”. Our results suggest
that in “Agni” enhanced diversion of photosynthate to roots resulted in more substrate being available to methanogenic bacteria
in the rhizosphere. Additionally, the more extensive vegetative growth of this cultivar may enhance methane transport from
the soil to the above-ground atmosphere. 相似文献
16.
Tea plant [Camellia
sinensis (L.) O.Kuntze)] is one of the most popular non-alcoholic beverage crops in the world today. In recent years, many clonal
tea cultivars have been developed and widely planted to replace the diverse traditional tea populations. In this article,
we study the relationships between classifications based on simple sequence repeat (SSR) markers and on morphological traits
for 185 tea plant cultivars. Results show that the genetic diversity index (H) is between 0.229 and 0.803, and the mean value is 0.543; the observed heterozygosity (H
o) ranges from 0.103 to 0.683, with an average of 0.340, while the genetic identity varies from 0.267 to 0.984. Based on tea-making
properties, the genetic diversity in the “black-green tea” group is much higher than in the “Oolong tea” group. Based on morphological
traits, cluster analysis classifies the 185 cultivars into three groups, “group I,” “group II” and “group III.” Most cultivars
are related based on the geographical origin and their genetic backgrounds. 相似文献
17.
Rhizodegradation is a technique involving plants that offers interesting potential to enhance biodegradation of persistent
organic pollutants such as polycyclic aromatic hydrocarbons (PAHs). Nevertheless, the behaviour of PAHs in plant rhizosphere,
including micro-organisms and the physico-chemical soil properties, still needs to be clarified. The present work proposes
to study the toxicity and the dissipation of phenanthrene in three artificially contaminated soils (1 g kg-1 DW). Experiments were carried out after 2 months of soil aging. They consisted in using different systems with two plant
species (Ryegrass—Lolium perenne L. var. Prana and red clover—Trifolium pratense L. var. fourragère Caillard), three kinds of soils (a silty-clay-loam soil “La Bouzule”, a coarse sandy-loam soil “Chenevières”
and a fine sandy-loam soil “Maconcourt”). Phenanthrene was quantified by HPLC in the beginning (T
0) and the end of the experiments (30 days). Plant biomass, microbial communities including mycorrhizal fungi, Rhizobium and PAH degraders were also recorded. Generally phenanthrene contamination did not affect plant biomass. Only the red clover
biomass was enhanced in Chenevières and La Bouzule polluted soils. A stimulation of Rhizobium red clover colonisation was quantified in spiked soils whereas a drastic negative phenanthrene effect on the mycorrhization
of ryegrass and red clover was recorded. The number of PAH degraders was stimulated by the presence of phenanthrene in all
tested soils. Both in ryegrass and red clover planted soils, the highest phenanthrene dissipation due to the rhizosphere was
measured in La Bouzule soils. On the contrary, in non-planted soils, La Bouzule soils had also the lowest pollutant dissipation.
Thus, in rhizospheric and non-rhizospheric soils the phenanthrene dissipation was found to depend on soil clay content. 相似文献
18.
Four strains of the phytopathogenic bacteriumCorynebacterium fascians (Tilford)Dowson were selected from our isolates and deposited in the Czechoslovak National Collection of Type Cultures (CNCTC) of the Institute
of Hygiene and Epidemiology in Prague. Two very virulent (Cor 83/82 “UPR” and Cor 82/81 “UP”) and one avirulent (Cor 81/80
“CP1b”) pelargonium strains, producing acid from rhamnose, were isolated from fasciations onPelargonium zonale W. One avirulent celery strain ofC. fascians (Cor 80/80 “CF4a”) was isolated from a root expiant ofApium graveolens L. growing on a nutrient mediumin vitro. Morphological, cultural, physiological and biochemical characteristics of these selected Czechoslovak isolates were compared
with the American patented strain cotype ATCC 12974. 相似文献
19.
The maintenance of exceptionally high numbers of folk varieties by the Piaroa people of the Venezuelan Amazon is considered.
We cataloged 113 manioc folk varieties, their nomenclature, use and relevant characters, revealing significant insights into
the role of manioc in Piaroa social life. Through a qualitative investigation of the cultivation, processing and symbolic
significance of manioc (Manihot esculenta) in two Piaroa regions over a period of 18 years, we have found that such agrobiodiversity can only be fully explained by
a combination of multiple factors, including pragmatic and ecological considerations, the subtle and complex diversity of
Piaroa manioc preparations and a variety of sociocultural factors, such as manioc’s role as a mediator of social relationships
and as a marker of cultural and social heritage.
相似文献
Stanford ZentEmail: |
20.
Dieter Korn 《Pal?ontologische Zeitschrift》2003,77(2):445-470
The anti-Darwinian “Typostrophe Theory” of O.H.Schindewolf can be put to the test by revisiting the ammonoid examples on which this macroevolutionary model was founded. It is shown
that none of the three theoretical elements saltationism, internalism, and cyclism can be supported by empirical data obtained
from ammonoid research. Putative saltations (“Typogenesis”) were feigned because of the lack of knowledge of intermediate
forms. Internalistic and orthogenetic development (“Typostasis”) can only be favoured by neglecting possible functions of
morphological characters. Preprogrammed extinction of “degenerated” clades (“Typolysis”) is unlikely when ruling out anthropocentric
views regarding ammonoid morphology. In terms of evolution of Palaeozoic ammonoids, there is no basis for the preference of
the “Typostrophe Theory” or some of its composing elements, including the “Type Concept” and “Proterogenesis”, over the Darwinian
evolutionary model and the Modern Synthesis.
相似文献