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1.
Amplified Fragment Length Polymorphisms (AFLPs) were employed within the taxonomically difficult Solanum nigrum L. complex in order to characterize the genetic diversity present in a collection of the Gatersleben Genebank, to classify taxonomically unknown material, and to correlate the clustering of the examined accessions with their geographic origin. The results from AFLP analyses using two primer combinations on 44 entries from five species led to the detection of four major clusters, simultaneously uncovering significant differences in the levels of genetic diversity within or between species. S. americanumexhibited the highest infraspecific variation despite close geographic origins, simultaneously being placed in a clearly separated cluster in comparison to the other examined species of the complex. In addition, these other species showed even less interspecific variation than was found at the infraspecific level in S. americanum. In terms of taxonomy, the application of AFLPs helped in the classification of 13 black nightshade accessions formerly only listed as Solanum sp. This also was confirmed by morphological determination. Furthermore, one accession formerly classified as S. physalifolium var. nitidibaccatum i) clustered with AFLPs and ii) was identified morphologically as S. villosum. Contradictory classifications remain for two further entries from the same species, found within the S. nigrum cluster after AFLP analyses, while belonging to S. physalifolium var. nitidibaccatum according to herbarium specimen. Finally, as indicated by the information on provenance in geographically separated subclusters in S. americanum and partially in S. villosum, clues on the currently unknown origin of accessions from the genebank seem feasible by AFLP data. 相似文献
2.
A standard electrophoretic method for wheat cultivar identification was used on single seeds to analyse the genetic integrity
of 11 wheat (Triticum aestivum L.) accessions after up to 24 seed reproductions in the Gatersleben genebank. It was clearly demonstrated that the gliadin
pattern of single seeds can be used to analyse the genotype composition of wheat accessions. Stability of electrophoretic
banding patterns was detected in eight accessions. Very week genetic drift was observed in three accessions. Our investigations
confirm experiences of the successful utilisation of protein markers for cultivar verification and genetic integrity testing
and demonstrate the high standard of wheat accessions maintenance in the Gatersleben genebank. 相似文献
3.
The collection, identification and maintenance of genebank accessions of the genus Trifolium is a major task because of the large number of genera and their occasional morphological similarity. We investigated whether
the measurement of nuclear DNA content can serve as an additional criterion for identification of mislabeled accessions. Relative
nuclear DNA content was determined by flow cytometry measurements for a total of 151 genebank accessions of 23 Trifolium species with notable agronomical value. Among 23 species analyzed, 15 were found to possess a uniform relative nuclear DNA
content, with intraspecific variability of the majority of analyzed species lower than 5%. Within six Trifolium species, 1–2 atypical accessions with outstanding differences in relative DNA content, chromosome number and morphological
features were found. In T. hybridum and partially in T. ambiguum these outstanding differences could be ascribed to variations in accession ploidy level. For the remaining atypical accessions,
the determined nuclear DNA content, chromosome number and morphological features were not related to those characteristic
of the species. Additionally taxonomic identity of atypical accessions was determined using ITS region sequencing and morphological
observations. We propose flow cytometric measurements of nuclear DNA content as simple and reliable technique which can be
used at seedling stage to verify identity and genetic stability of Trifolium genebank accessions. 相似文献
4.
Axel Diederichsen 《Genetic Resources and Crop Evolution》2008,55(3):419-440
A characterization of 10,105 accessions of hexaploid cultivated oat (Avena sativa L. sensu lato) from 85 countries of the Plant Gene Resources of Canada (PGRC) collection was conducted at Saskatoon, Saskatchewan,
Canada. Eight environmentally stable morphological characters (panicle type, panicle erectness, panicle density, lemma colour,
dorsal awn of lemma, ligula, major infraspecific group), differentiated into 18 character states, were used to define genetically
distinct morphological groups. Comparisons of oat diversity from different countries, among the major infraspecific groups
and among Canadian oat cultivars registered between 1886 and 2002 were possible. The 10,105 accessions represented 118 different
morphological groups. The number of accessions in each morphological group was unevenly distributed with the 13 most frequent
morphological groups including 90% of the accessions. The most frequent morphological groups in the PGRC collection were identical
with the most frequent types of Canadian oat cultivars. The greatest richness of diversity was found in oat from countries
with temperate climates and intensive oat breeding programmes. The oat accessions comprised 8,754 accessions of common hulled
oat, 183 accessions of hull-less oat and 1,168 accessions of red oat. For red oat (A. byzantina C. Koch), West Asia was richest in diversity. The USA could be considered a secondary centre of diversity for red oat and
Canada a secondary centre of diversity for hull-less oat. Morphological diversity of oat cultivars released in Canada increased
during the twentieth century. The morphological groups were related to formal taxonomical infraspecific classifications of
A. sativa. Applications of the concept of defining morphological groups for phenotyping a large germplasm collection are demonstrated
discussed. 相似文献
5.
H.B. Singh A. Singh A. Tripathi S.K. Rai R.S. Katiyar J.K. Johri S.P. Singh 《Genetic Resources and Crop Evolution》2003,50(4):339-343
Seventy accessions of coriander (Coriandrum sativum L.) were screened for resistance against stem gall, a severe disease caused by Protomyces macrosporus Unger., with the goal to select the resistant cultivars. The accessions PH-7, Pant Haritima, COR-17 and COR-2 were highly resistant. These may be used as the parents to breed high yielding accessions resistant to stem gall disease. 相似文献
6.
M. Costea D. M. Brenner F. J. Tardif Y. F. Tan M. Sun 《Genetic Resources and Crop Evolution》2006,53(8):1625-1633
The ‘Morelos’ accessions of Amaranthus from Mexico demonstrate taxonomic ambiguity at the basic morphologic level. The main cause is the enormous morphological
and genetic variation exhibited by the species in the genus. Although basic morphological criteria can be applied to herbarium
specimens or germplasm collections for quick taxonomic identification, the morphological data alone can be misleading. To
ascertain the taxonomic identity of the ‘Morelos’ accessions and their hypothesized species affiliation to Amaranthus caudatus or Amaranthus cruentus, we conducted a comparative analysis of phylogenetic relationships among these taxa/accessions using amplified fragment length
polymorphism (AFLP) and micromorphology methods. Based on AFLP data, all the controversial ‘Morelos’ accessions can be consistently
placed into a single A. cruentus species clade, which is clearly separated from the A. caudatus species clade. The AFLP-based phylogenetic relationship of ‘Morelos’ and delimitation of A. cruentus and A. caudatus are further supported by micromorphology, showing that the combination of these techniques can provide more reliable data
for germplasm identification than each method used alone. 相似文献
7.
Axel Diederichsen 《Genetic Resources and Crop Evolution》2007,54(3):661-678
An overview of ex situ collections of cultivated flax (Linum usitatissimum L.) and 53 other species of the genus Linum L. is presented. The names of 33 genebanks in 23 countries preserving Linum germplasm and the species preserved at these places are provided. World genebanks engage in ex situ preservation of about
48,000 accessions of cultivated flax (Linum usitatissimum). However, possibly only 10,000 accessions of these are unique. Of the ca. 200 species of the genus Linum, other than L. usitatissimum, 53 are reported to be represented in the world’s ex situ collections with a total of about 900 accessions. Of these, 279
accessions alone refer to the wild progenitor of cultivated flax, Linum bienne Mill. However, L. bienne from the region of origin of cultivated flax is rarely represented in genebank collections. References to publications describing
the techniques for ex situ conservation and the infraspecific variation of cultivated flax are made. It is suggested that
taxonomic species delimitation within the genus Linum is in need of clarification and that the variation in Linum species for ornamental use or use in breeding is investigated. 相似文献
8.
9.
10.
The domestication of cultivated flax (Linum usitatissimum L. subsp.usitatissimum) is briefly discussed.
Using data documented as a matter of routine in genebank work, 63 accessions of cultivated flax from the flax germplasm collection
of the Gatersleben Genebank are compared with 73 accessions of its wild progenitor pale flax (subsp.angustifolium (Huds.) Thell.), which have been observed in systematic field trials. Range of variation, genetically based variation, heritability
and correlation of several characters are considered, especially with respect to the influence of domestication.
Cultivated flax shows higher variation in the characters of generative plant parts, while pale flax varies more in the vegetative
parts of the plant.
The character correlations are similar in both subspecies. Of the 29 characters studied in pale flax the parameters describing
tillering, height of plant, weight of seeds, width of petals and width of leaves are especially suitable for distinguishing
between different accessions. In spite of the high heritabilities of most of the characters, the influence of the environment
is significant in most cases. 相似文献
11.
An ecogeographical analysis of the V. narbonensis complex and V. bithynica was conducted using herbarium specimens and genebank accessions. 956 specimens were included in the study from 26 herbaria, with geographical and ecological data recorded for each specimen. A distribution map of each taxa was produced, and the geographical and ecological preferences of each taxa were analysed and discussed. The taxa with the widest distribution were found to be V. narbonensis, V. bithynica and V. johannis, and the rarest taxa were V. galilaea var. galilaea and V. narbonensis var. aegyptiaca. The complex includes three endemic species; V. hyaeniscyamus, V. kalakhensis and V. eristalioides. The complex as a whole, was most frequently collected from grasslands, as a weed in cultivated fields and in wasteland. It showed a strong preference for calcareous soils. It was found that the quality of the passport data varied widely, but that in general the specimens from more recent collections included more detailed passport data. Herbarium specimens are invaluable in ecogeographic studies as the information obtained can be used as a guide for future collecting missions and in determining areas of importance when collecting material for conservation. Finally as the whole plant is available, the identification of each specimen can be checked. 相似文献
12.
Oryza officinalis complex is the largest and the most complicated group in the genus Oryza L., consisting of about ten species with the B, C, BC, CD, and E genomes. Taxonomy and identification of the species, particularly those with the B, C and BC genomes, are difficult due to the similar morphology and overlapping distribution of some species. The difference in ploidy levels of some species adds more complexity. In the present study, we surveyed 64 accessions of rice germplasm in the O. officinalis complex using RFLP analysis of PCR-amplified Adh genes in addition to chromosome counting. The results confirmed that all O. rhizomatis accessions are diploids with the C genome, whereas all O. minuta accessions are tetraploids having the BC genome. However, both diploid and tetraploid forms were found for the accessions identified in the genebank as O. officinalis, O. punctata and O. eichingeri. The tetraploid form of O. officinalis with the BC genome is exclusively distributed in India and has been described as O. malampuzhaensis. The tetraploid form of O. punctata which has been called O. schweinfurthiana by some workers was found to be as widely distributed as its diploid form in Africa. It is noteworthy that two accessions that had been determined as tetraploid O. officinalis were actually belonging to a species with the CD genome (O. latifolia). Our results promote a better understanding of the genomic constitutions of many accessions in the O. officinalis complex and correct determination of the genebank material, which serves as an important basis of germplasm cataloguing for further research and utilization. 相似文献
13.
Genetic diversity in Ethiopian hexaploid and tetraploid wheat germplasm assessed by microsatellite markers 总被引：4，自引：3，他引：4
Sentayehu Alamerew Sabina Chebotar Xiuqiang Huang Marion Röder Andreas Börner 《Genetic Resources and Crop Evolution》2004,51(5):559-567
The genetic diversity of a subset of the Ethiopian genebank collection maintained at the IPK Gatersleben was investigated applying 22 wheat microsatellites (WMS). The material consisted of 135 accessions belonging to the species T. aestivum L. (69 accessions), T. aethiopicum Jacubz. (54 accessions) and T. durum Desf. (12 accessions), obtained from different collection missions. In total 286 alleles were detected, ranging from 4 to 26 per WMS. For the three species T. aestivum, T. aethiopicum and T. durum on average 9.9, 7.9 and 7.9 alleles per locus, respectively, were observed. The average PIC values per locus were highly comparable for the three species analysed. Considering the genomes it was shown that the largest numbers of alleles per locus occurred in the B genome (18.4 alleles per locus) compared to A (10.1 alleles per locus) and D (8.2 alleles per locus) genomes. Genetic dissimilarity values between accessions were used to produce a dendrogram. All accessions could be distinguished, clustering in two large groups. Whereas T. aestivum formed a separate cluster, no clear discrimination between the two tetraploid species T. durum and T. aethiopicum was observed. 相似文献
14.
The management of genebank collections of cultivated potato is costly due to the need for in vitro maintenance and virus eradication. Therefore, it is important to set up conservation strategies, which prevent duplicates
entering the collections. In this study, 32 Nordic potato landraces were studied for 57 morphological traits and analysed
for amplified fragment length polymorphism (AFLP). Most landraces could be distinguished based on the morphological characters,
except five accessions. Using five primer combinations to generate 114 reproducible AFLPs, of which 63 (55%) were polymorphic,
the five morphologically indistinguishable accessions were placed into two groups with identical AFLP patterns, suggesting
that some of the accessions were redundant for long-term preservation. The AFLP data showed that the Nordic collection of
potato landraces is composed of genetically different clones, and morphological analysis revealed a wide range of variability.
This variability seems to be distributed randomly over the Nordic region since the cluster analysis based on AFLPs and morphological
traits revealed no grouping based on the country of origin. Principal component analysis suggests that fewer morphological
traits than used in this study will be sufficient to discriminate between different genotypes of cultivated potato (Solanum tuberosum L.). Future possibilities for rationalising potato collections are discussed. 相似文献
15.
Mahendra P. Darokar Suman P. S. Khanuja Ajit Kumar Shasany Sushil Kumar 《Genetic Resources and Crop Evolution》2001,48(6):555-558
Brahmi (Bacopa monnieri) is atraditional Indian medicinal plant known for its natural nootropicaction of saponins present in large amount in its shoots. Acollection of 24 B.monnieri accessions from differentagro-climatic zones of India and an introduction from Malaysiamaintained in the field genebank at CIMAP was analysed for RAPDvariation. Among the 40 random primers tested, 29 primers generatedone or more polymorphic bands. The number of polymorphic bandsgenerated was primer dependent, ranging from 2 to maximum of 8.Similarity matrices were generated from the RAPD data on the basis ofNei's estimates of similarity indices and dendrograms wereconstructed based on UPGMA clustering. All the accessions were foundto be in the range of 0.8–1.0 of similarity, which isindicative of a narrow genetic base among the various accessions witha medium level of polymorphism. It was possible to differentiateindividual accessions, showing differences in morphological andgrowth properties at DNA level. The observed low levels of geneticvariation were attributed to interplay of sexual and vegetative modesof reproduction and similarity of local environments in habitats ofB. monnieri. 相似文献
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17.
Landrace accessions have long been recognized as an important source of genetic diversity for crop species, and landraces are stored in genebanks across the world as genetic resources for future crop development. Landraces are also an important part of the human cultural heritage and as such they have been used for genetic studies to make inferences about historical agriculture. However, surprisingly little is known about the within-accession diversity of landrace crops of different species. In order to evaluate the diversity of Swedish landraces we used microsatellite markers to genotype accessions of four species (barley, pea, oats and rye), both extant genebank material and 114-year-old seed samples of similar geographic origin and type. We found consistently high levels of within-population genetic diversity in the historical material, but varying and often lower diversity levels in the genebank accessions. We also make tentative conclusions about how representative the genebank material is to what was originally cultivated in its reported area of origin and suggest that the true identity of the genebank accessions is unclear and that historical seed collections should be a more appropriate material for the study of historical agriculture. 相似文献
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19.
Jean-Pierre Labouisse Bayetta Bellachew Surendra Kotecha Benoît Bertrand 《Genetic Resources and Crop Evolution》2008,55(7):1079-1093
The aim of this article is to provide an overview of the current situation of coffee genetic resources that are dwindling
at an alarming rate in Ethiopia, the centre of diversity of Coffea arabica. Firstly, we describe the coffee growing systems (forest coffee, semi-forest coffee, garden coffee and plantation coffee)
and recent research on the genetic diversity of the coffee planting material associated with those systems. Whilst the maximum
genetic diversity revealed by DNA-based markers is found in the forest coffees of the south-western highlands, the natural
habitat of C. arabica, the taxonomy of coffee landraces is particularly rich in garden coffee systems located in ancient growing zones such as
Harerge in eastern Ethiopia. After reviewing the factors involved in the genetic erosion of the Ethiopian genepool, we give
an update on the status of coffee genetic resources conserved ex situ in the field genebank of the Jimma Agricultural Research Centre, with 4,780 accessions spread over 10 research stations located
in the main production areas, and in the main genebank of the Institute of Biodiversity Conservation located in Choche (Limu)
with 5,196 accessions conserved. Lastly, we mention the in situ conservation operations currently being implemented in Ethiopia. Improving our knowledge of the genetic structure of Ethiopian
forest and garden coffee tree populations as well as genetic resources conserved ex situ will help to plan the future conservation strategy for that country. To this end, modern tools as DNA-based markers should
be used to increase our understanding of coffee genetic diversity and it is proposed, with the support of the international
scientific community and donor organizations, to undertake a concerted effort to rescue highly threatened Arabica coffee genetic
resources in Ethiopia.
相似文献
| Jean-Pierre LabouisseEmail: |
20.
Perennial kale is a rare leafy vegetable and forage crop that is mainly vegetatively propagated and therefore expensive to
conserve ex situ. A genebank collection of 47 perennial kales and 34 reference samples from the main Brassica oleracea crop types were characterized with seven microsatellite markers in order to verify potential redundancies and to obtain more
insight in the position of perennial kales within B. oleracea. Based on the obtained results and on data from previous studies, the collection was reduced with 49% to 24 perennial kales.
Considering this level of reduction, it was estimated that the investments made for the final verification by microsatellite
analysis are returned after only 4-year time. A principal coordinate plot clearly separated the perennial kales from the other
crop types of B. oleracea, except in one case. This deviating accession of vegetatively preserved perennial kale clustered closely together with the
single seed-preserved accession of perennial kale included in the study. These two accessions occupied an intermediate position
between the group of vegetatively propagated perennial kales and the group of seed-propagated Brassica accessions, suggesting a hybridization background with another B. oleracea crop type. The microsatellite study demonstrated a close genetic relationship among the investigated perennial kales and
their unique position within B. oleracea. 相似文献