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Diversity and distribution of enset landraces (clones) were investigated in 300 randomly selected peasant households at ten different locations in the Sidama region of Ethiopia using presence-or-absence data. A total of 86 named landraces were recorded, making the region an area of remarkably high enset landrace diversity. A substantial fraction of the landraces had a restricted distribution range and low abundance while a number were moderately common with the remaining few being cosmopolitan. Regional distribution was positively correlated with local abundance, such that more widespread landraces were also typically more abundant (r = 0.78, p < .01). Landrace diversity was not evenly distributed throughout the region, the highest diversity being recorded in mountain areas (r = 0.71, p < .05). Farmers exchange planting materials extensively, resulting in a fairly high (up to 70%) coefficient of similarity among sites. Implications for the collection and conservation of enset genetic resources are discussed. 相似文献
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Nivaldo Peroni Paulo Yoshio Kageyama Alpina Begossi 《Genetic Resources and Crop Evolution》2007,54(6):1333-1349
This study focuses the inter-relationships among the men, the use, and the intra-specific 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. 相似文献
4.
为探讨有利于花椒园节肢动物群落结构的管理模式,2012年对云南省昭通市3种常见管理模式(粗放、免耕、精细)下花椒园节肢动物群落的组成和结构进行了系统调查。采用群落特征指数和主成分分析法对节肢动物群落特征、季节性变化及稳定性进行了研究。结果表明,调查区花椒园节肢动物群落由2纲9目97科318种组成,其中害虫主要种类为大青叶蝉(Tettigoniella viridis)、小绿叶蝉(Empoasca flavescens)、棉蚜(Aphis gossypii)和小长蝽(Nysius ercae),天敌主要种类为大灰食蚜蝇(Metasyrphus corolla)、斑食蚜蝇(Melanostoma scalare)、环腹瘿蜂属一种(Frigates sp.)和翠绿巨胸小蜂(Perilampus prasinus)。3种模式下,粗放模式丰富度(21.985 7)最高,但植食性类群亚群落个体比例(36.13%)也最高。免耕模式的多样性指数(3.649 1)、均匀性指数(0.694 3)和稳定性指数Ss/Si(0.074 7)、Nn/Np(0.557 2)、Sd/Sp(0.545 5)、Nd/Np(1.467 8)均高于其他两种模式。精细模式的优势度最高(0.193 1)、群落特征指数全年波动较大,受到外界干扰强烈。免耕模式下天敌对主要害虫的跟随作用较好且害虫爆发高峰期的虫口数量(最高81头)皆低于同时期粗放模式(最高189头)与精细模式(最高123头)。主成分分析表明粗放模式与精细模式下主导群落变化的主要因素为害虫,而免耕模式下天敌起到了主导作用,其对害虫的调控效果较好。因此综合考虑生态经济效益,免耕模式为有利于当地花椒种植的管理模式。 相似文献
5.
Garden floras interact with native biodiversity by providing resources for wildlife and by acting as a source of non-native species. Understanding the composition and richness of garden floras will help evaluate the relationships between these floras and the wider environment. The composition and richness of vascular plant floras were measured in a stratified sample of 61 urban, domestic gardens in Sheffield, UK, based on complete garden inventories. The entire garden flora contained 1166 species, of which 30% were native and 70% alien. Across gardens, aliens showed lower occupancy than natives, comprising 79% of the species recorded only once. The garden flora contained 146 plant families, which included 72% of the native, naturalised or recurrent casual families recorded in the wild in Britain and Ireland. Gardens contained on average 45% natives, irrespective of garden size. Garden area explained 30% of the variation in species richness within individual gardens. Doubling garden size led to an increase in species richness of 25%. The garden flora comprised 10% annuals, 63% biennial/perennials, 18% shrubs and 8% trees; shrubs were disproportionately composed of alien species. The floras of urban domestic gardens probably form the greatest source of potentially invasive alien plants. However, the plants found in domestic gardens have closer affinities with the uncultivated flora than is often perceived, and their role for wildlife in gardens deserves reassessment. Declines in garden size that result from recommendations on the density of new housing are unlikely to have major consequences for plant richness in gardens. 相似文献
6.
Hidetoshi Ikegami Hitoshi Nogata Keita Hirashima Mitsuo Awamura Takao Nakahara 《Genetic Resources and Crop Evolution》2009,56(2):201-209
Nineteen fig varieties and lines from Europe and Asia have been fingerprinted by ISSR, RAPD, and SSR markers, respectively,
using 13, 19, and 13 primer combinations. All primers produced 258 loci, with the highest number of loci (119) generated by
RAPD (R
p: 48.42). Clustering analysis was applied to the three marker datasets to elucidate the genetic structure and relationships
among these varieties. Mean genetic similarities were 0.787, 0.717, and 0.749, respectively, as determined using ISSR, RAPD,
and SSR. Each marker system produced incompletely separated clusters, although a weak binding group based on race type appeared
in the combined dataset. Comparisons of coefficients revealed no correlation between different similarity matrices; congruence
was observed between similarity matrices and co-phenetic matrices in all markers. Analysis of molecular variance (AMOVA) showed
that most of the total polymorphism was attributable to within-group variance (ISSRs + RAPDs, 97.41%; SSRs, 90.18%). These
results suggest that the genetic diversity of this fig population is low and that multiple marker utilization is critical
to estimate the relatedness of figs at the variety level. Additionally, it was presumed that ‘Houraihi’, the oldest variety
in Japan, was disseminated independently of other foreign varieties in the 17th century or before then. 相似文献
7.
Kamal K. Panda Anath B. Das Brahma B. Panda 《Genetic Resources and Crop Evolution》2009,56(5):629-637
Pandanus tectorius Parkinson (
P. fascicularis Lam.) of the family Pandanaceae constitutes one of the major bioresources of Ganjam coast, Orissa; used mainly in small scale
perfume industry for aromatic compound extracted from the male inflorescences. In order to establish genetic diversity, if
any related to perfume yield, samples of P. tectorius representing male populations from seven locations representing populations I–VII along the coastline of Orissa, India, were
analysed for somatic chromosome number, 4C genomic DNA content, randomly amplified polymorphic DNA (RAPD) as well as phytochemicals.
The somatic chromosome number in all the populations I–VII was 2n = 60. The chromosomes were of minute size without showing any remarkable structural variation. Like wise the average 4C DNA
content was 5.09 pg (≅4,912 Mbp) that showed no intra- or inter-population differences. Out of 54 decamer primers tested,
a total of 1,260 amplicons were obtained from 34 primers accounting 43.49% polymorphism. Molecular phylogenetic analysis of
the seven populations revealed two distinct branches, with populations II and III in one and the rest populations in the other
branch of the phylogenetic tree. It was important to note that the unique populations II and III confined to the Ganjam coast
of Orissa having RAPD markers: OPA 09–940 bp, OPA 09–705 bp, OPC 14–1,500 bp, OPC 14–700 bp, OPC 20–1,475 bp, OPC 20–1,350 bp,
OPC 20–920 bp and OPC 20–700 bp, were distinguished form the rest of the populations. The aforesaid populations (II and III)
are well known to produce aroma of high quality and yield, composed of primarily phenyl ethyl methyl ether (66.8–83%) and
terpinen-4-ol (5–12%) along with a number of other phyto-chemical compounds that support the flourishing perfume industry
and livelihood of the local people in the region. The findings underscored the possible role of local eco-geography in contributing
to the micro-evolution of unique high perfume yielding genotypes of P. tectorius that represented populations II and III at Ganjam coast, which were genetically distinct from the rest of the populations
revealed by RAPD analysis. 相似文献
8.
The recent loss of pollinating insects and out-crossing plants in agricultural landscapes has raised concern for the maintenance of ecosystem services. Wild bees have been shown to benefit from garden habitats in urban and suburban areas. We investigated the effects of distance from garden habitats on wild bees and seed set of a native out-crossing plant Campanula persicifolia, in intensively managed agricultural landscapes in Southern Sweden. Bee abundance and species richness, as well as plant seed set, were higher closer to gardens (<15 m) than further away (>140 m). This highlights private gardens as a landscape wide resource for pollinators but also the lack of sufficient pollination of wild plants in contemporary agricultural landscapes. 相似文献
9.
For the selection of donors with valuable characteristics for breeding, 39 thyme accessions were evaluated in three years
according to a staggered schedule. The criteria investigated were: winter hardiness, beginning of flowering, growth height,
yield of the dry herb, content of essential oil, composition of the essential oil, DNA content of cell nuclei and number of
chromosomes. The most strongly varying traits between the populations were the yield of dry herb, the content of essential
oil and the content of volatile phenols with coefficients of variation (CV) between CV 40% and 50%. The largest variation
within a population was detected for the yield of dry herb (CV 25–46%) and the content of essential oil (CV 17–48%). The homogeneity
of the populations was different. The minimal average coefficient of variation of all traits (CV 19%) was determined in the
population of the cultivar ‘Varico II’ and in a population from Lithuania. The ploidy level of T. vulgaris was diploid (2n = 30). 相似文献
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Giuseppina Logozzo Rosa Donnoli Leonardo Macaluso Roberto Papa Helmut Knüpffer Pierluigi Spagnoletti Zeuli 《Genetic Resources and Crop Evolution》2007,54(8):1763-1779
Common bean (Phaseolus vulgaris L.) was introduced in Europe from both Mesoamerican and Andean centres of origin. In this study, a collection including 544
accessions from all European regions showed that the Andean phaseolin types ‘T’ (45.6%) and ‘C’ (30.7%) prevailed over the
Mesoamerican ones ‘S’ (23.7%), and accessions with cuboid seed shape (34.9%), maroon coat darker colour seed (44.3%), uniform
seed colour (69.6%) were the most frequent. European accessions with phaseolin ‘S’ showed a significantly larger average seed
size compared to those from America in the same phaseolin class while those presenting ‘T’ and ‘C’ phaseolin did not. This
suggests that, during crop expansion in Europe, sampling or selection favoured the large-seeded races within the Mesoamerican
‘S’ gene pool or, possibly, introgression from Andean germplasm did occur. A core collection was developed using sampling
approaches based on the information available in the genebank databases and on phaseolin patterns. Four sampling strategies
were used: simple random sampling, and three random-stratified samplings, by logarithm of frequency of accessions by country,
by European region, and by phaseolin pattern, respectively. Two sampling strategies resulted in core collections significantly
different for phaseolin electrophoretic patterns from the whole collection. Stratification by phaseolin patterns increased
the frequency of ‘S’ types (‘C’ type = 33%, ‘T’ type = 5.7% and ‘S’ type = 31.3%). The core collections were validated using
seven seed characters, and no significant difference was observed in all strategies. This first developed European bean core
collection will help to assess the contribution of the two American gene pools to the European germplasm and their relative
importance for breeding purposes. 相似文献
12.
Small-fruited bitter gourds, the “pavel” and “pandi-pavel” described in Hortus Malabaricus, is nearly an extinct crop in Kerala
and rest of southern peninsular India. They are reported to have been cultivated extensively in the past. However, presently
its cultivation is restricted to a few home gardens in remote forest areas consequent on its replacement by large-fruited
cultivars over the last two centuries. Special traits like unique flavour, taste, medicinal properties and fruit fly tolerance
have enabled the perpetuation of this relict vegetable still in a few homesteads. Eleven named landraces have been collected
from South Western Ghats and Tamil Nadu plains and their seeds conserved in the genebank of NBPGR, New Delhi. Known as “uchie”
in Northern India and “methipavai” in Tamil, these miniature bitter gourds have different landrace names in specific pockets
of natural occurrence/cultivation. 相似文献
13.
David M. Cole Timothy L. White P. K. R. Nair 《Genetic Resources and Crop Evolution》2007,54(1):189-204
Knowledge of the effects of farmer practices on population genetic parameters of peach palm (Bactris gasipaes Kunth) is relevant to the improvement and conservation of the palm’s genetic resources. Microsatellite markers were used
to assess genetic diversity and population structure of peach palm in swidden-fallow agroforestry systems in northeastern
Peru. The study covered eight communities, comprising two study areas 160 km apart – one occupied by indigenous Amerindians
and the other by mixed race campesinos. Simultaneous analysis of an ex situ peach palm germplasm collection provided a means to compare population genetic parameters. Farmers who were surveyed on seed
selection practices for peach palm reported that an average of only four palms (4.3 for campesino and 1.5 for indigenous populations)
were used to provide seed for the establishment of the forest gardens sampled. As expected, inbreeding coefficients observed
within communities were relatively high (f = 0.105 − 0.210), however, observed heterozygosities within communities were also high (0.625–0.741). A metapopulation approach
was used to describe migration within and among regions, implying a hierarchical structure of gene flow which maintains relatively
high levels of genetic diversity. Seed migration was found to occur over longer distances (≤600 km) and at a higher frequency
(46% of palms sampled) in the indigenous study area, and a proportionally greater number of alleles was found (49 vs. 43 over
three loci) with twice as many private alleles occurring only in the indigenous populations. The farmers’ practice of preserving
remnant palms through successive swidden generations may have contributed to the maintenance of alleles by reducing the severity
of founder effects. Although the campesino study area exhibited a significant (20% of the variation; p < 0.01) isolation-by-distance relationship across 35 km distance, in general, both study populations had relatively limited
genetic structure (θ = 0.012–0.03), which is believed to have resulted from the exchange of seeds over long distances and
periods of time. 相似文献
14.
In western Germany, typical gardens of immigrant families were visited and periodically checked regarding their plant composition
and cultivation techniques. A preliminary inventory of the cultivated plants of the Langenberg region south of Bonn is given.
Chaerophyllum byzantinum Boiss. and Trachystemon orientalis (L.) G. Don as new crops, recently introduced from the wild flora of Turkey, and their utilization are shortly described.
Most gardening immigrants originate from farmers’ families and introduce local knowledge from their native countries. Personal
preferences to familiar or local varieties made them transfer the respective seeds or plants and in some cases even wild plants
to their new settling areas. Vicinity to German or immigrant gardeners from other nationalities allowed for exchange of seed
and experience. This way, German gardens became centers of increasing diversity for horticultural crops within the past few
decades. 相似文献
15.
Background River sediments are natural habitats of complex bacterial and fungal communities and therefore play a decisive role in the
mineralization process of organic matter in freshwater systems. By means of comparative temporal and spatial analyses of microbial
communities, the in situ impact of anthropogenically generated pollutants on these biofilm associations can be assessed and discriminated from seasonal
variations.
Aim The aim was the adaptation of hybridization with fluorescently labelled rRNA-targeted oligonucleotides (FISH) for the in situ characterization of the structural and functional diversity of native microbial communities in complex lotic sediments. The
impact of qualitatively and quantitatively different water pollutants on the microbial diversity, metabolic potential, and
relative abundance of characteristic bacterial groups was assessed by oligonucleotide probes on different phylogenetic levels.
In particular, sulfate reducing bacteria (SRB) were investigated to evaluate their potential applicability as microbial biomonitors
in sediments.
Methods Sediment samples from the German lowland rivers Elbe and Oder were investigated over 12 months with regard to physico-chemical
parameters and the composition of the attached microbial communities. Mechanical treatment including ultrasonification and
sagitation under aerobic conditions combined with the use of pyrophosphate ensured the equal dispersion of fixed microbial
cells within the sediment samples. The optimized whole-sediment FISH-technique was combined with an improved cell extraction
procedure and applied, due to the specific grain size fraction distribution, at the different sampling sites.
Resultsand discussion Up to 85.6% of the total bacterial cell counts as determined by DAPI (4’, 6-diamidino-2-phenylindole) staining could be successfully
monitored by the eubacterial oligonucleotide probe set EUB338, EUB338-II and EUB338-III, simultaneously indicating a high
proportion of Eubacteria and the high metabolic potential of the bacterial community. Desulfobacteriaceae could be detected by the specific probe SRB385Db in various relative percentages ranging from 2.4 to 16.0% of the total bacterial
cell counts. The total number of bacteria and the metabolic potential of sediment related bacteria were barely affected by
the different pollution pattern of the sampling sites.
Conclusions The pre-treatment step as conducted by cell extraction as well as the FISH hybridization procedure was successfully optimized
to the specific conditions present within freshwater sediments. Beside seasonal variations, particularly occurring at hydrologically
influenced sites, sampling sites with different pol lution levels could be successfully distinguished by the relative abundance
of Desulfobacteriaceae used as microbial indicator organisms.
Outlook The integration of ongoing insights into pollution induced changes of natural bacterial consortia should result in a system
of ecotoxicological classes representing the different ecological status of riverine systems. Physiological directed methods
like Community Level Physiological Profiling (CLPP) or Pollution Induced Community Tolerance (PICT), and structural techniques
as FISH or microarrays should be used to investigate the influence of harmful substances on the biodiversity in natural microbial
sediment communities. 相似文献
16.
Korarima (Aframomum corrorima (Braun) P.C.M. Jansen) production is declining mainly due to destruction of the plant’s natural habitat. A survey was conducted
in the three major korarima growing administrative zones, Gamo Gofa, Debub Omo and Kaffa in southern Ethiopia to assess indigenous
production practices, wealth status, farm based biodiversity and household characteristics using participatory rural appraisal
(PRA) and semi-structured questionnaires. The wealth is unevenly distributed among households and not significantly different
for korarima growers and non-korarima growers. Farmers acknowledged that shortage of shade trees; low yield and lack of improved
varieties had contributed to decrease in production area (PA). A total of three distinct named korarima landraces were recorded,
with a range from one to three on individual farms implying low farm based biodiversity. More households grew enset (Ensete ventricosum (Welw.) Cheesman) in Gamo Gofa and Kaffa while maize (Zea mays L.) was grown by nearly all households in Debub Omo. Only a few households grew korarima. Most of the household characteristics
significantly affected the PA of korarima. The correlation coefficients indicated that the relationship of household characteristics
were significant. Findings of this study suggest that the maintenance of shade trees on the main farm field is the main requirement
for korarima production. 相似文献
17.
Private, residential gardens form a substantial proportion of the undeveloped land in urban areas. Evaluating their role in supporting biodiversity is crucial to (i) predicting which plant and animal species can persist in towns and cities, (ii) understanding the regional impacts of urbanisation, and (iii) guiding sympathetic garden management by owners. To obtain baseline information on a poorly-studied component of garden biodiversity, we measured the size and composition of the cryptogam assemblages in 61 domestic gardens in the city of Sheffield, UK. A total of 67 bryophyte and 77 lichen taxa were recorded. Bryophytes ranged from 3 to 24 species per garden, with a mean richness of 11.3 species; lichens ranged from 2 to 30, with a mean of 14.9 species. Stone substrates supported the highest lichen richness, although minor substrates contributed unique species. Just over one fifth of bryophyte species were recorded in grass lawns, and these were more widespread than those of other habitats. Most cryptogams were scarce, with around one quarter of both bryophytes and lichens occurring in single gardens, and only 10% were found in more than half of the gardens. Garden area - correlated with substrate richness - and garden altitude were the only two factors explaining variation in cryptogam richness (bryophytes 39.1%, lichens 32.4%). Positive correlations existed among bryophyte, lichen and vascular plant richness, and these were only partially mediated by the effect of garden area. Therefore the opportunity remains for garden owners to support cryptogam richness, the most effective action being to enhance substrate diversity. 相似文献
18.
Juliana Massimino Feres Marcela Corbo Guidugli Moacyr Antonio Mestriner Alexandre Magno Sebbenn Ana Yamaguishi Ciampi Ana Lilia Alzate-Marin 《Genetic Resources and Crop Evolution》2009,56(6):797-807
Deforestation in southeast Brazil has led to the extinction of Hymenaea courbaril var. stilbocarpa and ex situ conservation has been established. In this study, the levels of genetic diversity and the effective population size of H. courbaril in a germplasm bank were investigated using six nuclear microsatellite loci. A total of 79 and 91 alleles were found in 65
seed-trees and their 176 offspring, respectively. Offspring have a higher average number of alleles per locus (A = 15.2) than seed-trees (A = 13.2), but lower observed heterozygosity (offspring: H
o = 0.566; seed-trees: H
o = 0.607). The estimate of outcrossing rate shows that the study population is perfectly outcrossed (t
m
= 0.978, P > 0.05). Significant deviations from random mating were detected through mating among relatives and correlated matings. The
average variance in effective population size for each family was 2.63, with a total effective population size retained in
the bank of 170.1. These results confirm that the preserved population of H. courbaril retains substantial genetic variability.
Moacyr Antonio Mestriner and Ana Lilia Alzate-Marin—CEEFLORUSP Members. 相似文献
19.
A. Buerkert M. Oryakhail A. A. Filatenko K. Hammer 《Genetic Resources and Crop Evolution》2006,53(1):91-97
After 23 years of war, current information about the biodiversity of crops in the Hindukush mountains of Afghanistan is scarce.
This study aimed at assessing the genetic composition of farmers wheat (Triticum spp.) populations through a survey of 21 randomly chosen cereal fields on both sides of the Panjsher river in the upper Panjsher
valley of Northern Afghanistan. A stratified sampling of wheat heads according to morphological differences was followed by
estimates of field size and grain yield and a formal interview with the landowner about the cropping sequence and the inputs
used. About 75% of the cereal fields were cropped in rotation systems with faba bean (Vicia faba L.), barley (Hordeum vulgare L.), potato (Solanum tuberosum L.), maize (Zea mays L.) or fallow. Manure application at between 2.3 and 5.3 t ha−1 was the major source of nutrient inputs at grain yield levels between 1.2 and 4.7 t ha−1. The morphological characterization of the collection revealed 19 taxonomically different varieties of bread wheat (Triticum aestivum L.) but also barley and triticale (Triticosecale Wittm.) grown in mixtures. Populations within one field consisted of up to seven botanical wheat varieties. Farmers did not
differentiate between morphological differences within such mixtures but identified their populations instead according to
grain color, cooking properties and resistance to mildew and frost. Triticum aestivum var. subferrugineum was the most widespread wheat variety and no effects of altitude on biodiversity of wheat was noted across the transect.
Particularly interesting was the occurrence of T. aestivum var. subferrugininflatum and var. subgraecinflatum which so far have only been reported from Mongolia. The finding of triticale indicated the active seed exchange with lowland
or long-distance seed sources. 相似文献
20.
Maria Soledad Ureta Miguel Cantamutto Alicia Carrera Carla Delucchi Monica Poverene 《Genetic Resources and Crop Evolution》2008,55(8):1267-1277
Two introduced wild species Helianthus annuus L. and H. petiolaris Nutt. have become widespread in central Argentina and overlap the sunflower crop region. Intermediate off-type plants between
the wild and cultivated species are often found, which is of concern because of the recent release of imidazolinone resistant
varieties and the likely use of genetically modified sunflower cultivars. The progeny of 33 off-type plants obtained from
14 representative sites of the diffusion area were studied to confirm hybrid origin. Germination, survival, morphological
traits and days to flowering confirmed hybridization between crop and both wild species, when compared to eight accessions
of typical wild plants. Some progenies were presumably crop–wild H. annuus hybrids, some originated from the cross of cultivated plants and H. petiolaris, and two were the advanced generation of a cultivated hybrid. Hence, morphological traits are a good clue for the identification
of spontaneous hybrid plants at field. The results indicate that crop–wild hybridization and introgression occur at various
places in central Argentina. This fact may represent a way to herbicide resistance escape and future transgene escape if GM
sunflower cultivars are released for commercial use. 相似文献