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1.
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
2.
Total 65 lotus accessions in genus Nelumbo mainly collected from China, were subjected to random amplified polymorphic DNA (RAPD) markers to estimate the genetic diversity
and to test the genetic basis of the relationships between morphotypes and molecular markers. Seventeen primers generated
a total of 195 highly reproducible and discernible loci, among which 173 were polymorphic. Percent polymorphism varied from
66.7 to 100 with an average of 88.72, and five primers out of them, OPC05, OPG10, OPN20, OPP09 and OPS17, showed 100% polymorphism.
A relatively high genetic diversity was detected among all the samples with the similarity coefficient values ranging from
0.45 to 0.85, and Nei’s gene diversity (h) 0.30, and Shannon index (I) 0.46. The UPGMA dendrogram clustered 65 accessions in four clusters and the clustering pattern showed two groups, N. nucifera ssp. nucifera and those accessions related to the American lotus, and some special cultivars, landraces, hybrids and the American lotus.
Principal Coordinate Analysis (PCA) further indicated that the genetic diversity of Nelumbo accessions was not evenly distributed, instead, was presented by a clustered distribution pattern. Similar to the results
revealed by the dendrogram, two main groups representing the two subspecies of N. nucifera, as well as some special landraces, cultivars of Chinese lotus, the Japanese lotus and hybrids out of the two groups were
obtained. Neither the UPGMA dendrogram nor the PCA analysis exhibited strict relationship with geographic distribution and
morphotypes among the accessions. 相似文献
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5.
N. P. S. Dhillon R. Ranjana Kuldeep Singh I. Eduardo A. J. Monforte M. Pitrat N. K. Dhillon P. P. Singh 《Genetic Resources and Crop Evolution》2007,54(6):1267-1283
Diversity among 36 snapmelon landraces, collected from 2 agro-ecological regions of India (9 agro-climatic sub-regions), was
assayed using RAPD primers, morphological traits of plant habit and fruit, 2 yield-associated traits, pest and disease resistance
and biochemical composition (TSS, ascorbic acid, titrable acidity). Typical differences among accessions were observed in
plant and fruit characteristics and snapmelon germplasm with high titrable acidity and possessing resistance to downy mildew,
Cucumber mosaic virus, Zucchini yellow mosaic virus, Papaya ringspot virus, Aphis gossypii and Meloidogyne incognita was noticed in the collection. RAPD based grouping analysis revealed that Indian snapmelon was rich in genetic variation
and region and sub-region approach should be followed across India for acquisition of additional melon landraces. Accessions
of var. agrestis and var. momordica clustered together and there was a separate cluster of the accessions of var. reticulatus. Comparative analysis of the genetic variability among Indian snapmelons and an array of previously characterized reference
accessions of melon from Spain, Israel, Korea, Japan, Maldives, Iraq, Pakistan and India using SSRs showed that Indian snapmelon
germplasm contained a high degree of unique genetic variability which was needed to be preserved to broaden the genetic base
of melon germplasm available with the scientific community.
N. P. S. Dhillon and Ranjana contributed equally to this work and are considered the first authors. 相似文献
6.
Marc Moragues Marian Moralejo Mark E. Sorrells Conxita Royo 《Genetic Resources and Crop Evolution》2007,54(5):1133-1144
A comprehensive characterization of crop germplasm is critical to the optimal improvement of the quality and productivity
of crops. Genetic relationships and variability were evaluated among 63 durum wheat landraces from the Mediterranean basin
using amplified fragment length polymorphisms (AFLPs) and microsatellites markers. The genetic diversity indices found were
comparable to those of other crop species, with average polymorphism information content (PIC) values of 0.24 and 0.70 for
AFLP and microsatellites, respectively. The mean number of alleles observed for the microsatellites loci was 9.15. Non-metric
multi-dimensional scaling clustered the accessions according to their geographical origin with the landraces from the South
shore of the Mediterranean Sea closely related. The results support two dispersal patterns of durum wheat in the Mediterranean
basin, one through its north side and a second one through its south side. 相似文献
7.
Marie Malice Nicolas Martin Audrey Pissard Jorge A. Rojas-Beltran Antionio Gandarillas Pierre Bertin Jean-Pierre Baudoin 《Genetic Resources and Crop Evolution》2007,54(4):685-690
ISSR molecular markers have been used to investigate genetic diversity of oca (Oxalis tuberosa Mol.), an Andean neglected tuber crop species. Sampling procedure allowed a preliminary study of the genetic diversity at
the intra- and intervarietal levels. Twenty tuber lots conserved in situ in the microcentre of Candelaria and ex situ in the Toralapa Centre (Bolivia) were identified. Four ISSR primers amplified a total of 25 fragments of which 17 (68%) were
polymorphic. These experiments show that the structure of oca varieties is mainly based upon vernacular names with a greater
differentiation among tuber lots than within them, supporting agromorphological data. ISSR technique enlightened the existence
of heterogeneous varieties in oca and divergence between in situ and ex situ conservation strategies. These observations are potentially linked to the different ways of management of tubers in these
two conservation systems. 相似文献
8.
Bettina Heider Elke Fischer Tanja Berndl Rainer Schultze-Kraft 《Genetic Resources and Crop Evolution》2007,54(3):529-542
Pueraria montana var. lobata and P. phaseoloides originating from tropical Asia and parts of Oceania are ecologically and economically important legumes that are used as
green manure, cover crop or forage plants. Conservation and use of plant genetic resources require an understanding of the
extent and distribution of genetic diversity in any given region. In this study, genetic variation of five P. montana var. lobata and 16 P. phaseoloides accessions was analysed developing a random amplified polymorphic DNA (RAPD) marker methodology for Pueraria species and thereby creating basic data for follow-up research and the development of conservation strategies. Seeds were
collected from native populations in Bac Kan Province, a mountainous region in Northeast Vietnam. P. montana var. lobata presented a high level of variation with 54.3% of the detected markers being polymorphic, whereas P. phaseoloides exhibited an intermediate to high level of variation (45.5%). The P. montana var. lobata accessions clustered in congruence with their eco-geographical origin. For P. phaseoloides no correspondence between sampling sites and genetic differentiation was found. Inter-population differentiation was measured
as Jaccard's similarity coefficient (JSC). Mean JSC amounted to 0.35 in P. montana var. lobata and 0.52 in P. phaseoloides. Results are compared to other genetic studies of herbaceous legumes and conservation strategies are suggested. 相似文献
9.
Genetic diversity of seven Rhus L. species was assessed using random amplified polymorphic DNA (RAPDs) markers. Initially, 90 primers were screened, of which 25 produced reproducible amplification products. These primers generated a total of 296 bands, with an average of 11.8 bands per primer. Out of 296 bands scored, 236 (80%) were polymorphic and 62 (20%) were monomorphic. Primers OPC-05 and OPD-05 generated 100% polymorphic bands. The resolving power of primers ranged from 9.4 to 26.8. Similarity matrix values ranged from 0.45 to 0.63. The dendrogram generated using Unweighted Pair Group Method using Arithmetic Averages (UPGMA) grouped all the species of Rhus in one major group with two sister groups, whilst R. pyroides Burch. and R. dentata Thunb. were outliers. R. gerrardii (Harv. ex Engl.) Diels, R. glauca Thunb. and R. pentheri Zahlbr. constituted one sister group, while R. natalensis Bernh. ex C. Krauss and R. gueinzii Sond. were included in the other. The degree of genetic diversity observed between seven species of Rhus with RAPD markers suggest that this approach could be used for studying the phylogeny of the genus. 相似文献
10.
Cecilia Y. Kato Chifumi Nagai Paul H. Moore Francis Zee Minna S. Kim Denise L. Steiger Ray Ming 《Genetic Resources and Crop Evolution》2005,51(8):815-825
Pineapple (Ananas comosus (L.) Merr.) cultivars, often derived from somatic mutations, are propagated vegetatively. It has been suggested by isozyme data that there is little genetic variation among Smooth Cayenne cultivars. A thorough investigation of the genetic variation within the cultivated speciesAnanas comosus, particularly among commercial cultivars, will provide critical information needed for crop improvement and cultivar protection. One-hundred and forty-eight accessions ofA. comosus and 14 accessions of related species were evaluated with AFLP markers. The average genetic similarity ofA. comosus was 0.735 ranging from 0.549 to 0.972, suggesting a high degree of genetic variation within this species. With AFLP markers, discrete DNA fingerprints were detected for each commercial cultivar, breeding line, and intra-specific hybrid. Self-incompatibility, high levels of somatic mutation, and intraspecific hybridization may account for this high degree of variation. However, major cultivar groups of pineapple, such as Cayenne, Spanish, and Queen, could not be distinctively separated. These cultivar groups are based on morphological similarity, and the similar appearance can be caused by a few mutations that occurred on different genetic background. Our results suggest that there is abundant genetic variation within existing pineapple germplasm for selection, and discrete DNA fingerprinting patterns for commercial cultivars can be detected for cultivar protection. The genetic diversity and relationships of fourAnanas species are also discussed. 相似文献
11.
Genlou Sun 《Genetic Resources and Crop Evolution》2007,54(8):1737-1746
Elymus trachycaulus complex species are known for their morphological variability, but little is known about their genetic basis. The phylogenetic
relationships among the E. trachycaulus complex, and their systematic relation to other species in Triticeae remain unknown. Nucleotide diversity of ribulose-1,5
bisphosphate-carboxylase (rbcL) gene in E. trachycaulus complex species and several other Triticeae was first characterized and compared. A primary conclusion of the present study
is that nucleotide diversity for rbcL gene in E. trachycaulus species was detected with the estimates of nucleotide diversity θ = 0.00039 and π = 0.00043. The estimate of nucleotide diversity
in rbcL gene for species with different genome constitution here ranged from 0.00099 (π) and 0.00099 (θ) for the species with Ns
genome to 0.00226 (π) and 0.00291 (θ) for the species with St genome. The phylogenetic relationships of these species were
assessed using these rbcL sequences. A total of 47 variable positions including 19 parsimony-informative sites were detected among 24 accessions of
18 species/subspecies. The species with St, H/I and Ns genomes well separated from each other, and formed a three distinct
clades with higher bootstrap values support for both Parsimony and NJ analyses. The St genome containing species is sister
group of H/I genome containing species. Our result confirms that Pseudoroegneria is the maternal genome donor to these Elymus species studied here, regardless of their distribution. Elymus trachycaulus complex are more related to each other than to E. glaucescens, E. patagonicus, and E. solandri. This study suggested that Elymus species with StH genomes may form from multiple closely related sets of donors. 相似文献
12.
L. S. Rao P. Usha Rani P. S. Deshmukh P. A. Kumar S. K. Panguluri 《Genetic Resources and Crop Evolution》2007,54(6):1235-1244
Detection of genetic relationships between 19 chickpea cultivars and five accessions of its wild progenitor Cicer reticulatum Ladizinsky were investigated by using RAPD and ISSR markers. On an average, six bands per primer were observed in RAPD analysis
and 11 bands per primer in ISSR analysis. In RAPD, the wild accessions shared 77.8% polymorphic bands with chickpea cultivars,
whereas they shared 79.6% polymorphic bands in ISSR analysis. In RAPD analysis 51.7% and 50.5% polymorphic bands were observed
among wild accessions and chickpea cultivars, respectively. Similarly, 65.63% and 56.25% polymorphic bands were found in ISSR
analysis. The dendrogram developed by pooling the data of RAPD and ISSR analysis revealed that the wild accessions and the
ICCV lines showed similar pattern with the dendrogram of RAPD analysis. The ISSR analysis clearly indicated that even with
six polymorphic primers, reliable estimation of genetic diversity could be obtained, while nearly 30 primers are required
for RAPD. Moreover, RAPD can cause genotyping errors due to competition in the amplification of all RAPD fragments. The markers
generated by ISSR and RAPD assays can provide practical information for the management of genetic resources. For the selection
of good parental material in breeding programs the genetic data produced through ISSR can be used to correlate with the relationship
measures based on pedigree data and morphological traits to minimize the individual inaccuracies in chickpea. 相似文献
13.
Twenty nine germplasm lines of Chenopodium quinoa and two of Chenopodium berlandieri subsp. nuttalliae were evaluated for 12 morphological and 7 quality traits for two test seasons. The 19 traits were analyzed for cluster and
principal component analysis. The first four PCs contributed 78.70 % of the variability among the germplasm lines. The first
PC accounted for 39.5% of the variation and had inflorescence/plant, plant height and stem diameter as the traits with largest
coefficients, all with positive sign. The characters with greatest positive weight on PC2 were days to maturity (0.309), inflorescence length (0.260) and branches/plant. All the germplasm lines were grouped into
six clusters based on average linkage method. Cluster III had high values for seed yield and most of the quality traits but
showed a small seed size. The dendrogram separated the two lines of C. berlandieri subsp. nuttalliae from the quinoa lines. 相似文献
14.
The eleven most known landraces from central and southern Italy were analysed using ISSR markers on 15 randomly chosen individuals
for each landrace, with the aim of assessing genetic variation within and among landraces and possibly ascertaining their
origin and genetic relationships. A total of 164 loci were observed, 128 of which (78.05%) were polymorphic. Gene diversity
over all landraces was I = 0.3759. The highest within-landrace diversity was observed in samples from the Apennine ridge and for one Sicilian landrace;
on the other hand, samples from the small Sicily islands were less variable. Principal Component Analysis and AMOVA allowed
the discrimination of groups of landraces with higher similarity. Analyses indicate that the small Sicily islands landraces
are very closely related to one another and seem to be derived from the peninsular material; moreover, they help disclose
relationships among geographically close landraces. The knowledge so acquired can, therefore, contribute to elaborate strategies
for increasing the economical value of élite landraces and to protect producers from frauds. 相似文献
15.
Jorge Cunha Margarida Baleiras-Couto José P. Cunha Jorgete Banza Adelaide Soveral Luís C. Carneiro José E. Eiras-Dias 《Genetic Resources and Crop Evolution》2007,54(5):981-988
Wild populations of Vitis vinifera L.␣have been located in Portugal. Morphological characterization was carried out in three populations located in Alcácer
do Sal, Castelo Branco, and Montemor-o-Novo, and then compared using multivariate discriminant analysis. These populations
were from three different hydrological basins, therefore cross-pollination was not possible. It was verified that in each
population all plants were different. The data suggest that the frequency of female and male plants is rather variable in
wild populations. The morphology of the adult leaf, from the Alcácer do Sal population, had particular features when compared
with Castelo Branco and Montemor-o-Novo populations, which were more homogeneous. The length of teeth compared with width
at the end of the base, and the density of prostrate hairs between and on main veins (lower side) were the variables which
allowed the best discrimination among populations. 相似文献
16.
Agromorphological and molecular variability in the genus <Emphasis Type="Italic">Sesbania</Emphasis>
Green manuring especially in rice wheat cropping systems of many tropical and subtropical countries is regaining importance
due to increased fertilizer costs and environmental considerations. Many species of Sesbania genus have been reported as potential green manure crops. The genus is not well characterized and there is a lot of ambiguity
over the nomenclature and classification of the species of this genus. A pilot study based on agro-morphological and molecular
data was conducted to examine the interspecific and intraspecific variability in the selected species of Sesbania genus that were collected from diverse geographical locations and are recommended or traditionally used as green manures.
The study revealed a lot interspecific variability at both morphological and molecular level. It was also shown that species-specific
genetic markers could be generated. The potential use of such markers in Sesbania breeding program is discussed. The study also emphasizes the utilization of molecular profiling for proper identification
and classification of the species of this genus. In addition, various limitations in breeding and utilization of Sesbania as a green manure crop and the potential of a radiation induced late flowering mutant (Trombay Sesbania rostrata-1; TSR-1) for crop improvement is also discussed. 相似文献
17.
S. D. Segura G. Coppens d’Eeckenbrugge C. H. Ocampo P. Ollitrault 《Genetic Resources and Crop Evolution》2005,52(4):455-463
In a general study of banana passion fruit genetic resources, diversity was analyzed in the two main cultigens, P. tripartita
var. mollissima and P. tarminiana, and their closest wild relative, P. mixta, scoring isozyme bands (IDH,PGM,ACP,PGD,DIA,andPRX)
on288 plants from 31 accessions. Polymorphismandallelic richness, Nei diversity indices, and neighbor joining clustering showed
that variation was poor in the cultigens in northern and central Colombia, while P. mixta appeared much more polymorphic.
The populations of P. tripartita var. mollissima and P. mixta from southern Colombia and Ecuador show higher diversity values
and are clearly differentiated from those of central and northern Colombia. This geographic component of variation is even
stronger than the interspecific one, which suggests a close relation and a regular gene flow between these two species. In
contrast, all the accessions of P. tarminiana constitute a clearly differentiated group, even if some introgression with P.
tripartita var. mollissima is also suspected. The high variation observed in the southern region indicates the proximity of
a center of diversity for banana passion fruit and collecting in Ecuador, Peru and Bolivia is recommended. The high diversity
of P. mixta and the evidence of gene flow with P. tripartita var. mollissima constitute a favorable context for the implementation
of in situ conservation strategies. 相似文献
18.
M. C. Vaz Patto P. M. Moreira V. Carvalho S. Pego 《Genetic Resources and Crop Evolution》2007,54(7):1555-1563
The Portuguese maize bread (“broa”) manufactured from traditional maize landraces still plays an important economic and social
role on Central and Northern rural communities of the country. However the traditional maize landraces agricultural systems
are changing. Local maize landraces are in risk of disappearing because of the progressive adoption of hybrid varieties not
suitable for bread production. These changes are contributing to a major loss of genetic diversity. An expedition took place
in the Central region of Portugal (Beira Interior and Beira Litoral) with the purpose of collecting enduring maize landraces
with technological ability for bread production and to access the possibility of establishing a participatory plant breeding
and conservation program. A total of 51 different maize landraces and 175 other varieties of associated crops were collected.
Maize landraces showed to maintain high diversity and potential for improvement. The production relayed on small farms with
polycrop, quality oriented, sustainable systems. A participatory plant breeding and conservation program would be possible
on this region with the proviso that local authorities would be involved. This program would allow a higher valuation of these
maize populations, contributing to halt the current loss of these unique Portuguese maize landraces. 相似文献
19.
S. Desai Ch. Narayanaiah Ch. Kranti Kumari M. S. Reddy S. S. Gnanamanickam G. Rajeswara Rao B. Venkateswarlu 《Biology and Fertility of Soils》2007,44(1):229-234
Jatropha (Jatropha curcas L.) is a non-edible oil-seed plant with adaptability to marginal semi-arid lands and wastelands. The Indian Government is
promoting jatropha to reduce dependence on the crude oil and to achieve energy independence by the year 2012, under the National
Biodiesel Mission. Selected strains of Bacillus spp., either supplemented with or without chitin, were tested for their ability to promote growth of jatropha seedlings in
pot culture studies. The strains supported growth of jatropha seedlings up to 42 days after sowing. Among all strains, Bacillus pumilus (IM-3) supplemented with chitin showed over all plant growth promotion effect resulting in enhanced shoot length (113%),
dry shoot mass (360%), dry root mass (467%), dry total plant mass (346%), leaf area (256%), and chlorophyll content (74%)
over control. Treating seeds with strain IM-3 without chitin resulted in enhanced dry shoot mass (473%), dry total plant mass
(407%), and chlorophyll content (82%). However, Bacillus polymyxa (KRU-22) with chitin supported maximum root length (143%). Either strain IM-3 alone or in combination with other promising
strains could be promoted further for enhanced initial seedling growth of jatropha. 相似文献
20.
Hirut Kebede Gloria Burow Raviprakash G. Dani Randy D. Allen 《Genetic Resources and Crop Evolution》2007,54(4):885-895
Since Upland cotton (Gossypium hirsutum) is known to have relatively low levels of genetic diversity, a better understanding of variation and relationships among
possible sources of novel genes would be valuable. Therefore, analysis of genetic variation of the genus Gossypium, especially the diploids, which are the putative donors of the A and D genomes for the commercially important allotetraploid
cottons (AADD), G. hirsutum and G. barbadense, could provide important information about the feasibility of using these genetic resources for cotton improvement. The primary
objective of this study was to analyze the genetic diversity in A-genome diploid cotton species, G. herbaceum (A1) and G.␣arboreum (A2) by using microsatellite markers. Forty-one A-genome germplasm accessions were evaluated with 32 microsatellite loci.
Genetic similarities between A1 and A2 ranged from 0.62 to 0.86 with a mean of 0.70. Within each A-genome species similarities
ranged from 0.80 to 0.97 with a mean of 0.89 for A1 and from 0.82 to 0.98 with a mean of 0.89 for A2. A UPGMA tree and principal
coordinate analysis based on genetic similarity matrices showed distinct clusters consistent with the genomic groups. 相似文献