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1.
T. N. Zhebentyayeva G. L. Reighard D. Lalli V. M. Gorina B. Krška A. G. Abbott 《Tree Genetics & Genomes》2008,4(3):403-417
Amplified fragment length polymorphisms (AFLP) and targeted simple sequence repeats (SSR) were employed to assess genetic
similarity of North American apricots having natural resistance to plum pox virus (PPV) within diversified germplasm including
six nondomesticated apricot species. On a dendrogram constructed from 231 AFLP loci, the position of the North American cultivars
reflects relatedness to the European apricots and introgression of non-European germplasm as well. The occurrence of diagnostic
AFLP markers supports an introgression of Chinese germplasm into the North American PPV resistant assortment and supports
a different breeding history for ‘Stark Early Orange’ (SEO) and Goldrich-Harlayne lineages. Five SSR loci linked to the PPV
resistance region on G1 provided evidence that the investigated lineages (SEO and ‘Harlayne’–‘Goldrich’) have the same or
related source of resistance introduced presumably from Northern China. Possible introgression of genetic material from nondomesticated
apricots P. mandshurica sp, P. sibirica var. davidiana and P. mume sp. was detected and discussed.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
2.
Nationalization and Globalization Trends in the Wild Mushroom Commerce of Italy with Emphasis on Porcini (
Boletus edulis
and Allied Species). This paper presents an historical overview of wild mushroom commerce in Italy, with a focus on recent trends in the production
of porcini (Boletus edulis and closely allied species). Over the past century, two major trends—nationalization and globalization—have been apparent
in the wild mushroom commerce of Italy. First, a simplified national mushroom menu has emerged through processes of governmental
regulation and culinary fashion, but it has come at the expense of differing, localized mushroom traditions which may suffer
under the European Union’s free trade principles. Second, Italy has emerged as a focal point of a global market for a small
number of mushroom species—particular porcini. While the name porcini has become synonymous with Italian cuisine, and in spite
of a vibrant tradition of recreational mushroom collecting in Italy, most of the porcini commercially available in Italy or
exported by Italy are no longer of Italian origin. Porcini and other mushrooms now flow into Italy from all over the world—especially
from China and eastern Europe—and are then often exported as “Italian porcini.” This globalization of the wild mushroom trade,
while offering significant income to rural producers and processors around the globe, has other effects as well, for example,
a kind of national branding as “Italian” of globally-produced products, of which porcini is one, that is in direct opposition
to some of the European Union’s rules for regional denominations.
Processi di Nazionalizzazione e Globalizzazione nel Commercio Italiano dei Funghi spontanei, con Particolare Riguardo ai Porcini ( Boletus edulis e Specie Affini). Questo articolo presenta una panoramica storica sul commercio dei funghi spontanei in Italia, con particolare riguardo alle recenti tendenze nella produzione dei porcini (Boletus edulis e specie affini). Nello scorso secolo si sono osservate due tendenze principali—di nazionalizzazione e di globalizzazione—nel commercio dei funghi spontanei in Italia. In primo luogo si è affermata nel territorio nazionale una tradizione limitata al consumo di un numero contenuto di specie, sia per effetto di alcune normative che di mode culinarie, ma ciò è avvenuto a discapito di tradizioni locali più ricche, che potrebbero ulteriormente risentire dei principi per il libero scambio all’interno dell’Unione Europea. In secondo luogo, l’Italia si è posta in evidenza come un punto nodale per il mercato globale di alcune specie fungine, in particolare dei porcini. Nonostante quest’ultimo termine sia tradizionalmente associato alla cucina italiana, e nonostante esista in Italia una vivace e radicata tradizione nella raccolta amatoriale dei funghi, la maggior parte dei porcini ivi commercializzati (allo stato fresco, essiccati o variamente conservati) o esportati verso altri paesi non sono più di origine locale. I porcini e altre specie fungine giungono attualmente in Italia da ogni parte del mondo—in modo particolare dalla Cina e dall’Europa orientale—e sono successivamente spesso esportati come “prodotti Italiani.” Questo processo di globalizzazione del mercato dei funghi spontanei, pur offrendo un significativo introito ai raccoglitori e commercianti rurali su tutto il globo, è responsabile di altri effetti, come per l’appunto una sorta di marchio nazionale “Italiano” su alcuni prodotti di provenienza globale, come per l’appunto i porcini, cosa che contrasta con alcune delle regole dell’Unione Europea in materia di denominazioni regionali.相似文献
3.
Aphanomyces astaci (Saprolegniales, Oomycetes) is classified among the 100 world’s worst invasive species. This species is endemic to North
America and has been introduced into Europe by imports of their hosts, the North American crayfish species. As a consequence,
extensive mass mortalities involved several populations of the European crayfish. Here, we checked its occurrence in four
Italian populations of Procambarus clarkii, the most widespread alien crayfish in Italy. Digital image analyses and image processing techniques were used to select
micro-melanized areas in the subabdominal cuticle of 2–10 crayfish per population. All the selected areas tested positive
for A. astaci ITS nrDNA specific primers; moreover, the obtained sequences clearly corresponded to A. astaci, thus revealing that P. clarkii is an active carrier of this oomycete in Italy. Decisions are to be urgently made to control the spread of both P. clarkii and A. astaci for the conservation of the indigenous crayfish biodiversity. 相似文献
4.
Spartaco Gippoliti 《Biodiversity and Conservation》2012,21(6):1359-1364
The role of ex situ activities for the conservation of biodiversity, and of zoos and aquaria in particular, is open to continuing debate. The
present note highlights the conservation breeding potential of zoological gardens and aquaria in the European union, but it
also recognises the lack of a convincing scientific and legal framework that encourages ex situ activities for ‘exotic’ species. If ex situ programmes are considered essential for global biodiversity conservation, the EU should not limit itself to regulating zoos
through the zoo directive, but should actively promote and support their ex situ conservation activities. 相似文献
5.
Alginate encapsulation is a simple and cost-effective technique to preserve plant germplasm but there are only a few reports
available on preservation of encapsulated explants of two highly valuable groups of tropical trees, the eucalypts (Myrtaceae)
and mahoganies (Meliaceae). This study investigated alginate encapsulation for preservation of the eucalypt hybrid, Corymbia torelliana × C. citriodora, and the African mahogany, Khaya senegalensis. We assessed shoot regrowth of encapsulated shoot tips and nodes after storage for 0, 3, 6 and 12 months on media varying
in sucrose and nutrient content, under storage conditions of 14°C and zero-irradiance. Encapsulated explants of both trees
were preserved most effectively on high-nutrient (half-strength Murashige and Skoog) medium containing 1% sucrose, which provided
very high frequencies of shoot regrowth (92–100% for Corymbia and 71–98% for Khaya) and excellent shoot development after 12 months’ storage. This technique provides an extremely efficient means for storage
and exchange of eucalypts and mahoganies, ideally suited for incorporation into plant breeding and germplasm conservation
programs. 相似文献
6.
Pasquale L. Curci Domenico De Paola Gabriella Sonnante 《Molecular ecology resources》2016,16(2):562-573
In this study, new chloroplast (cp) resources were developed for the genus Cynara, using whole cp genomes from 20 genotypes, by means of high‐throughput sequencing technologies. Our target species included seven globe artichokes, two cultivated cardoons, eight wild artichokes, and three other wild Cynara species (C. baetica, C. cornigera and C. syriaca). One complete cp genome was isolated using short reads from a whole‐genome sequencing project, while the others were obtained by means of long‐range PCR, for which primer pairs are provided here. A de novo assembly strategy combined with a reference‐based assembly allowed us to reconstruct each cp genome. Comparative analyses among the newly sequenced genotypes and two additional Cynara cp genomes (‘Brindisino’ artichoke and C. humilis) retrieved from public databases revealed 126 parsimony informative characters and 258 singletons in Cynara, for a total of 384 variable characters. Thirty‐nine SSR loci and 34 other INDEL events were detected. After data analysis, 37 primer pairs for SSR amplification were designed, and these molecular markers were subsequently validated in our Cynara genotypes. Phylogenetic analysis based on all cp variable characters provided the best resolution when compared to what was observed using only parsimony informative characters, or only short ‘variable’ cp regions. The evaluation of the molecular resources obtained from this study led us to support the ‘super‐barcode’ theory and consider the total cp sequence of Cynara as a reliable and valuable molecular marker for exploring species diversity and examining variation below the species level. 相似文献
7.
Jennifer K Rowntree Silvia Pressel Margaret M Ramsay Aneta Sabovljevic Marko Sabovljevic 《In vitro cellular & developmental biology. Plant》2011,47(1):55-64
The use of in vitro techniques for conservation has been rising steadily since their inclusion in The Convention on Biological Diversity and
The Global Strategy for Plant Conservation. Unfortunately, bryophytes are often overlooked in conservation initiatives, but
they are important in a number of large-scale ecosystem processes, i.e. nutrient, water and carbon cycling. There is a long history of the use of tissue culture in cultivating bryophytes, and many
species respond well to in vitro techniques. For 6 yr (2000–2006), The Royal Botanic Gardens, Kew and the UK statutory conservation agencies supported a project
for the ex situ conservation of bryophytes. Living and cryopreserved collections of UK threatened species were successfully established and
the cryopreserved collection continues to be maintained. Other in vitro conservation collections are maintained over Europe, at botanic gardens, museums and by individual university researchers,
but there is no coherent European collection of bryophytes for conservation, or standardisation of techniques. A major issue
for many in vitro collections is the maintenance of within species genetic diversity. Such diversity is considered to be important, as it is
the basis by which populations of species can adapt to new conditions and evolve. We are proposing to establish a European
network for in vitro conservation of bryophytes. We envisage that this will include living collections, cryopreserved collections and spore collections.
Conservation of genetic diversity would be a priority and the collections would provide a valuable resource for conservation
initiatives and support research into rare and threatened species. 相似文献
8.
Daniel L. Potts W. Stanley Harpole Michael L. Goulden Katharine Nash Suding 《Biological invasions》2008,10(7):1073-1084
Changes in vegetation structure and composition, particularly due to the invasion of exotic species, are predicted to influence
biosphere-atmosphere exchanges of mass and energy. Invasion of Cynara cardunculus (cardoon or artichoke thistle), a perennial, non-native thistle in coastal California grasslands presently dominated by non-native
annual grasses, may alter rates of ecosystem CO2 exchange and evapotranspiration (ET). During spring and summer 2006, we compared midday maximum net ecosystem CO2 exchange (NEE) and ET among adjacent grassland plots where Cynara was present and where it was absent. Measurements of NEE supported the prediction that deeply-rooted Cynara increase midday ecosystem C-assimilation. Cynara-mediated shifts in NEE were associated with increases in ecosystem photosynthesis rather than changes in ecosystem respiration.
Furthermore, the presence of Cynara was associated with increased ET during the growing season. An increase in aboveground live biomass (a proxy for leaf area)
associated with Cynara invasion may underlie shifts in ecosystem CO2 and water vapor exchange. Following mid-growing season sampling during April, we removed Cynara from half of the Cynara-containing plots with spot applications of herbicide. Three weeks later, midday fluxes in removal plots were indistinguishable
from those in plots where Cynara was never present suggesting a lack of biogeochemical legacy effects. Similar to woody-encroachment in some semi-arid ecosystems,
Cynara invasion increases midday ecosystem CO2 assimilation and evapotranspiration rates and has the potential to increase C-storage in California coastal grasslands. 相似文献
9.
Bettina Heider Meike S. Andersson Rainer Schultze-Kraft 《Biodiversity and Conservation》2007,16(6):1617-1631
Flemingia macrophylla (Willd.) Kuntze ex Merr., a multi-purpose legume with potential as dry-season forage crop, mainly occurs in subhumid to humid
environments of tropical and subtropical Asia. Despite increasing interest in conservation of germplasm suitable for low-input
production systems information on the genetic diversity of F. macrophylla is extremely scarce. The creation of baseline data is supposed to contribute to more efficient conservation management and
to identify collecting strategies of novel germplasm. Random amplified polymorphic (RAPD) markers were used to investigate
the genetic variation among 37 F. macrophylla accessions. Germplasm analysed in this study originated from Bac Kan province, Northeast Vietnam. Eight primers generated
a total of 47 amplified RAPD loci of which 38 were polymorphic. Jaccard’s similarity coefficients among accessions ranged
from 0.069 to 1 with a mean of 0.67. The UPGMA dendrogram revealed three clusters along with three outliers. No correspondence
between geographic and genetic distance was found (Mantel test: R = 0.21; P = 0.016). Analysis of molecular variance (AMOVA) revealed significant (P < 0.001) differentiation between accessions collected in lowland and upland regions. Results of UPGMA clustering were confirmed
by the pattern of principle coordinates analysis (PCO) plotting. Future collecting strategies should target populations at
large distances and along the altitudinal range. Ex situ conservation should encompass those accessions that showed genetic
divergence. In situ conservation may consist of establishing a system of interconnected population fragments to guarantee
continuing genetic exchange via corridors and of rehabilitating degraded habitats. 相似文献
10.
Fernanda Kokowicz Pilatti Tarsis Aguiar Thiago Simões Erica E. Benson Ana Maria Viana 《In vitro cellular & developmental biology. Plant》2011,47(1):82-98
The Brazilian biomes (Amazon, Atlantic Forest, Cerrado, Caatinga, Pantanal, and Pampa) comprise one of the highest levels
of plant diversity in the world; however, non-sustainable practices, deforestation, and land use have resulted in significant
losses and fragmentation of the native forests. These ecosystems are now threatened and protection of their native plants
through ex situ conservation is an urgent necessity. Cryopreservation and in vitro conservation are complementary options for securing and protecting Brazil’s native plant species because their potential
economic value is critically important to develop strategies that will (1) support their sustainable utilization, (2) protect
against the over-exploitation of species growing in natural habitats, and (3) conserve the genetic diversity of germplasm
from species of different provenances. Biotechnological approaches will help to address future economic and environmental
demands placed upon already at-risk species. Conserving seed germplasm ex situ provides an additional safeguard against the risks (e.g., loss due to disease, climate change) of field conservation. Moreover, seed banks and cryobanks permit the long-term conservation
of a wider genetic base; this offsets the labor and space intensive costs of conserving in the active growing state. This
paper is a compilation of the current status of strategies applied for conserving Brazilian native plant species. 相似文献
11.
M.J. Iqbal O.U.K. Reddy K.M. El-Zik A.E. Pepper 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(4):547-554
Reliable information about the evolutionary and genetic relationships of various germplasm resources is essential to the establishment
of rational strategies for crop improvement. We used AFLPs to study the genetic relationships of 43 cultivars of Gossypium hirsutum representative of the genomic composition of modern ’Upland’ cotton. The study also included representatives of the related
tetraploid species Gossypium barbadense, as well as the diploid species Gossypium raimondii, Gossypium incanum, Gossypium herbaceum and Gossypium arboreum. We tested 20 primer combinations that resulted in a total of 3,178 fragments. At the species level, and above, genetic similarities
based on AFLPs were in agreement with the known taxonomic relationships. Similarity indices ranged from 0.25 to 0.99. Representatives
of the G. hirsutum germplasm resources utilized in North America, including secondary accessions collected by breeders in Central America (’Acala’,
’Tuxtla’, ’Kekchi’) and the southwestern US (’Hopi Moencopi’), formed a single cluster with exceedingly limited genetic diversity
(with many pairwise similarity indices >0.96) We concluded that these accessions were derived from the same genetic pool.
The early maturing or ’latifolium’ or ’Mexican Highlands’ cultigens from which these cultivars were derived appear to have
had extremely limited genetic diversity, perhaps as a result of a severe genetic bottleneck resulting from the selection pressures
of domestication. Outside of the major G. hirsutum cluster, well-supported phylogenies were inferred. Inside this cluster, phylogenies were obscured by limited diversity, reticulation
and lineage sorting. The implications of these findings for cotton improvement are discussed.
Received: 23 May 2000 / Accepted: 23 January 2001 相似文献
12.
Patricia Ann Okubara Camille M. Steber Victor L. DeMacon Nathalie L. Walter Timothy C. Paulitz Kimberlee K. Kidwell 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,119(2):293-303
The necrotrophic root pathogens Rhizoctonia solani AG-8 and R. oryzae cause Rhizoctonia root rot and damping-off, yield-limiting diseases that pose barriers to the adoption of conservation tillage
in wheat production systems. Existing control practices are only partially effective, and natural genetic resistance to Rhizoctonia has not been identified in wheat or its close relatives. We report the first genetic resistance/tolerance to R. solani AG-8 and R. oryzae in wheat (Triticum aestivum L. em Thell) germplasm ‘Scarlet-Rz1’. Scarlet-Rz1 was derived from the allohexaploid spring wheat cultivar Scarlet using
EMS mutagenesis. Tolerant seedlings displayed substantial root and shoot growth after 14 days in the presence of 100–400 propagules
per gram soil of R. solani AG-8 and R. oryzae in greenhouse assays. BC2F4 individuals of Scarlet-Rz1 showed a high and consistent degree of tolerance. Seedling tolerance was transmissible and appeared
to be dominant or co-dominant. Scarlet-Rz1 is a promising genetic resource for developing Rhizoctonia-tolerant wheat cultivars because the tolerance trait immediately can be deployed into wheat breeding germplasm through cross-hybridization,
thereby avoiding difficulties with transfer from secondary or tertiary relatives as well as constraints associated with genetically
modified plants. Our findings also demonstrate the utility of chemical mutagenesis for generating tolerance to necrotrophic
pathogens in allohexaploid wheat.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
P. A. Okubara and C. M. Steber contributed equally to this work. 相似文献
13.
Forty-five sorghum germplasm growing in the Eastern Highlands of Ethiopia were evaluated for 10 qualitative traits. Phenotypic
frequencies between the accessions from each of the nine Aanaas and Alemaya University, grouped in 10 localities were tabulated.
Phenotypic diversity index, H′, was analysed and the result indicated the between localities component of diversity to be relatively smaller than the variation
in H′ among characters within localities. The value of H′ for all sample germplasm ranged from 0.36 to 0.95 with a mean of 0.71. The results showed that there is a wide morpho-agronomical
diversity among the sample germplasm studied. This information can be used for the conservation of these germplasm resources
and future improvement work of the sorghum crop. 相似文献
14.
J.-M. Lacape D. Dessauw M. Rajab J.-L. Noyer B. Hau 《Molecular breeding : new strategies in plant improvement》2007,19(1):45-58
A series of 320 mapped simple sequence repeats (SSRs) have been used to screen the allelic diversity of tetraploid Gossypium species. Fourty-seven genotypes were analyzed representing (i) the wide spectrum of diversity of the cultivated pool and
of the primitive landraces of species G. hirsutum (‘marie-galante’, ‘punctatum’, ‘richmondi’, ‘morrilli’, ‘palmeri’, and ‘latifolium’, and ‘yucatanense’), and (ii) species
G. barbadense, G. darwinii and G. tomentosum. The polymorphism of 201 SSR loci revealed 1128 allelic variants ranging from 3 to 17 per locus. Neighbor-joining (NJ) method
based on genetic dissimilarities produced groupings consistent with the assignments of accessions both at species and at race
level. Our data confirmed the proximity of the Galapagos endemic species G. darwinii to species G. barbadense. Within species G. hirsutum, and as compared to the other 6 races, race yucatanense appeared as the most distant from cultivated genotypes. Race yucatanense
also exhibited the highest number of unique alleles. The important informative heterogeneity of the 201 SSR loci was exploited
to select the most polymorphic ones that were assembled into three series of genome-wide (i.e. each homoeologous AD chromosome
pair being equally represented) and mutliplexable (× 3) SSRs. Using one of these ‘genotyping set’, consisting of 39 SSRs (one
3-plex for each of the 13 AD chromosomes pairs) or 45 loci, we were able to assess the relationships between accessions and
the topology in the genetic diversity sampled. Such genotyping set of highly informative SSR markers assembled in PCR-multiplex,
while increasing genotyping throughput, will be applicable for molecular genetic diversity studies of large germplasm collections.
Electronic Supplementary Material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
15.
Ibrokhim Y. Abdurakhmonov Sukumar Saha Jonnie N. Jenkins Zabardast T. Buriev Shukhrat E. Shermatov Brain E. Scheffler Alan E. Pepper John Z. Yu Russell J. Kohel Abdusattor Abdukarimov 《Genetica》2009,136(3):401-417
Cotton is the world’s leading cash crop, but it lags behind other major crops for marker-assisted breeding due to limited
polymorphisms and a genetic bottleneck through historic domestication. This underlies a need for characterization, tagging,
and utilization of existing natural polymorphisms in cotton germplasm collections. Here we report genetic diversity, population
characteristics, the extent of linkage disequilibrium (LD), and association mapping of fiber quality traits using 202 microsatellite
marker primer pairs in 335 G. hirsutum germplasm grown in two diverse environments, Uzbekistan and Mexico. At the significance threshold (r
2 ≥ 0.1), a genome-wide average of LD extended up to genetic distance of 25 cM in assayed cotton variety accessions. Genome
wide LD at r
2 ≥ 0.2 was reduced to ~5–6 cM, providing evidence of the potential for association mapping of agronomically important traits
in cotton. Results suggest linkage, selection, inbreeding, population stratification, and genetic drift as the potential LD-generating
factors in cotton. In two environments, an average of ~20 SSR markers was associated with each main fiber quality traits using
a unified mixed liner model (MLM) incorporating population structure and kinship. These MLM-derived significant associations
were confirmed in general linear model and structured association test, accounting for population structure and permutation-based
multiple testing. Several common markers, showing the significant associations in both Uzbekistan and Mexican environments,
were determined. Between 7 and 43% of the MLM-derived significant associations were supported by a minimum Bayes factor at
‘moderate to strong’ and ‘strong to very strong’ evidence levels, suggesting their usefulness for marker-assisted breeding
programs and overall effectiveness of association mapping using cotton germplasm resources.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
16.
A landrace (‘Moscatella’) and a commercial cultivar (‘Starkspur Red’) of Malus pumila Mill. were maintained and proliferated in vitro for ≥ four years. A factorial experiment, planned to evaluate the response of the two cultivars in conservation in determined
slow growth conditions, was carried out for eighteen months. Single node cuttings were stored in 4 different media, at 4 °C,
in dark conditions, in microvessels to assess the feasibility of reducing space in in vitro gemplasm banks. Culture viability after storage was evaluated after 6, 8,12 and 18 months of storage. Both varieties showed
high survival percentages for up to a year of conservation, but the landrace's capability to resume growth dropped dramatically
afterwards. On the contrary, ‘Starkspur Red’ maintained substantially unchanged capacity of resuming vigorous growth after
18 months of conservation. Overall, microvessels appeared to be suitable for storing single node cuttings under slow growth
conditions up to a year at least. The described techniques could be useful for in vitro germplasm collections where frequent subculturing enhances the risk of genetic changes and personnel, energy and materials
costs limit the amount of genotypes that can be managed.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
17.
Hedia Bourguiba Lamia Krichen Jean-Marc Audergon Bouchaib Khadari Neila Trifi-Farah 《Plant Molecular Biology Reporter》2010,28(4):578-587
The impact of mapped microsatellites on the study of genetic diversity of Tunisian apricot accessions was assessed. The genetic
variability of 47 traditional apricot cultivars originating from several areas in Tunisia was investigated with 32 polymorphic
microsatellite loci selected for their location throughout the eight linkage groups of Prunus genome. The higher polymorphism and greater transportability of these markers among Prunus species were proved by the expected heterozygosity (He = 0.56) and Shannon’s index of diversity (I = 1.05), indicating that Tunisian apricot germplasm maintained a substantial level of genetic diversity. According to their
geographical origin, the genetic differentiation among groups (north, center, and south; Fst = 0.04) was lower, while the
gene flow among groups was consequent (Nm = 4.79), attesting a narrow genetic background of apricot in the country. Both unweighted
pair-group method with arithmetic mean dendrogram, based on Nei’s genetic distances and factorial correspondence analysis,
separated northern cultivars from central and southern cultivars, revealing the same molecular basis of apricot material in
the Center and the South of Tunisia. These results revealed the efficiency of mapped markers for genetic variability measurements
compared to randomly ones, however, no advantage was observed considering the genetic relationships among studied accessions. 相似文献
18.
Y. Djè D. Forcioli M. Ater C. Lefèbvre X. Vekemans 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(1-2):157-163
The level of genetic diversity and the population genetic structure of sorghum landraces from North-western Morocco have
been investigated based on direct field-sampling using both allozyme and microsatellite markers. As expected, microsatellite
markers showed a much higher degree of polymorphism than allozymes, but relative measures of genetic structure such as Wright’s
inbreeding coefficient F
IS and Nei’s coefficient of genetic differentiation G
ST were similar for the two sets of markers. Substantial inbreeding was found to occur within fields, which confirms that sorghum
is predominantly selfing under cultivation. Most of the genetic diversity in Moroccan landraces occurs within fields (more
than 85%), as opposed to among fields or among regions, a result which contrasts to those of studies based on accessions from
germplasm collections. It is suggested that individual fields of sorghum constitute valuable units of conservation in the
context of in situ conservation practices.
Received: 8 December 1998 / Accepted: 28 December 1998 相似文献
19.
Graziano Rossi Gilberto Parolo Laura A. Zonta Julie A. Crawford Andrea Leonardi 《Biodiversity and Conservation》2006,15(12):3881-3893
The purpose of this study was to determine the conservation status of a Salix herbacea L. population, located in the N-Apennines (Italy), toward the southern edge of the species’ distribution. A 3 year-long study
(1999–2001) was conducted to evaluate the effects of human trampling on Salix herbacea. Two stands, one trampled and one untrampled in the same site, were compared. The measured variables included: total vegetation
cover; cover and female catkin number of Salix herbacea. The trampled stand showed a decrease in both Salix cover and sexual reproduction. We suggest possible conservation strategies to preserve the Salix herbacea trampled stand from its local extinction. 相似文献
20.
Swen Follak 《Central European Journal of Biology》2011,6(3):457-469
Pueraria lobata (kudzu) is an invasive weed originating from East Asia. Local infestations have been recently observed in Switzerland and
northern Italy; however, the potential for P. lobata to spread and to become abundant and damaging in the Alpine countries is not known. The aim of this study was to project
the potential distribution of P. lobata under current climate in Switzerland, Austria and Slovenia and parts of northern Italy using the ecoclimatic model CLIMEX.
In addition, areas at risk were identified where P. lobata may occur as a strong and aggressive competitor. This was derived from the plants’ distribution and climatic requirements
in the south-eastern United States where the heaviest infestations occur. Projections show that 60.84% of the total land area
of northern Italy, followed by 47.08% of Slovenia, 21.01% of Austria and only 1.97% of Switzerland are climatically suitable.
P. lobata may become a troublesome weed due to very favourable climatic conditions only in some parts of northern Italy and Slovenia.
In climatically suitable areas, any occurrence of the plant should be carefully observed. In infested and highly climatically
suitable areas, there is a need for strategic management to prevent further spread of P. lobata. 相似文献