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1.
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
2.
K. Persson R. von Bothmer M. Gullord E. Gunnarsson 《Genetic Resources and Crop Evolution》2006,53(4):857-866
Phenotypic diversity for agronomic characteristics was determined in an experiment with 29 landraces and 14 improved varieties
of rye from the Nordic area, Germany and Poland. The accessions were scored for 12 characters. Effects of the location, year,
type, and country of origin for landraces were investigated with analysis of variance. Phenotypic variations for the traits
were estimated using the Shannon–Weaver diversity index. The genetic variation was high, with an average of H 0 = 0.566. The landraces from Norway, Sweden and Finland showed the highest variation, whereas the improved varieties had the
lowest. The German material also had low variation but the status of this material is uncertain. The genetic diversity showed
that 70% of the variation was found within the accessions. A cluster analysis was carried out to identify the relationship
between the accessions. The material grouped into eight clusters, where clusters I to V included landraces from Sweden, Finland
and Norway, except for cluster III, which included one improved variety from Denmark. Cluster VI comprised a single Swedish
landrace from Gotland. Most of the improved varieties were in cluster VII and the last cluster contained accessions from Germany
and Sweden. 相似文献
3.
Ambiguity exists about the level of genetic diversity represented by farmer crop varieties, how it develops over time and
how it relates to the diversity comprised by formal varieties. As part of an interdisciplinary technological/sociological
study on farmer management of gene flow, upland rice (Oryza sativa L.) and late millet (Pennisetum glaucum (L.) R.Br.) from The Gambia were investigated for morphological and molecular variation. The goal of these analyses was to
obtain insight into the level of crop genetic diversity of farmer’s materials planted in several case study villages in The
Gambia. For both crops, samples were collected from villages and various research institutes. Based on variety names, different
rice and millet varieties were expected to be used in different villages. In fact, there was a large overlap in genetic diversity
for both crops, masked by the use of synonyms. The considerable similarity in rice genetic diversity between villages most
likely results from the exchange of varieties between farmers. For millet this seems the result of development of varieties
from the same gene pool. Some farmer varieties of rice, however, are apparent hybrid forms between the species O. sativa and O. glaberrima Steud., and farmer varieties in general displayed higher levels of genetic diversity than formal varieties. This indicates
that, for rice, genetic diversity develops in farmers’ fields and may have potential use in formal breeding programs. 相似文献
4.
5.
Abdelfattah Badr Hanaa H. El-Shazly Linda E. Watson 《Genetic Resources and Crop Evolution》2008,55(1):21-31
The origin and ancestry for Egyptian clover, Trifolium alexandrinum, was examined using AFLP data. The data support a close relationship of T. alexandrinum accessions from Syria and Egypt to T. apertum, T. berytheum, and T. salmoneum. However, crossability and geographic distributions suggest that T. apertum is an unlikely progenitor. In contrast, T. salmoneum appears to be the most probable progenitor for Syrian material of Egyptian clover, although a close relationship to T. berytheum was also revealed. The ability of these species to cross freely indicates that T. salmoneum and T. berytheum may be regarded as the primary ancestors from, which man domesticated Egyptian clover through artificial selection in Syria.
Following domestication, the earlier forms of the crop species could have been taken into rain-fed cultivation in Palestine
and irrigated cultivation in Egypt. In this regard, the domestication of Egyptian clover may be analogous to other crops,
such as barley and wheat, which were also domesticated in the Fertile Crescent and taken into cultivation in the Nile Valley.
It appears that genetic improvement of the crop occurred in Egypt after cultivation, and that the varieties that were developed
in Egypt were later distributed worldwide. 相似文献
6.
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
7.
The genetic diversity and the relationships among a collection of Brassica napus L. European populations were evaluated using random amplified polymorphic DNA markers. The study included 33 accessions of
B. napus collected from Galicia (northwestern Spain) and 18 British cultivars, 16 accessions of B. napus and two accessions of Brassica oleracea L. used as controls. DNA from 25 individuals per population was analyzed using 18 decamer primers. One hundred thirty-eight
amplification products were scored of which 105 were polymorphic. These bands ranged in size from 350 to 2500 base pairs.
Similarity coefficients and cluster analysis were computed and six groups were obtained. Cluster I was the largest and included
all the landraces from northwestern Spain, except two accessions that grouped separately into Clusters III and IV, respectively.
A low level of genetic variability was detected among the B. napus Spanish genotypes, while considerable diversity was present among the British ones, which grouped into three groups, two
main clusters and one group formed by one accession. Cluster II included all commercial varieties grown in Great Britain whereas
Cluster V grouped local varieties maintained by the growers for many years. Cluster VI was a singularity formed by one entry.
British accessions of B. oleracea had the greatest dissimilarity with all the other populations and grouped separately in Clusters VII and VIII. As conclusion,
B. napus landraces used in northwestern Spain as leafy-green vegetable probably have an independent origin from B. napus crops grown in other European regions. Besides, separate domestication in northwestern Spain and Great Britain for a different
end use might have led to two distinct gene pools. 相似文献
8.
Morphological and molecular diversity analysis among the Indian clones of <Emphasis Type="Italic">Sesuvium portulacastrum</Emphasis> L. 总被引:1,自引:1,他引:0
Vinayak H. Lokhande Tukaram D. Nikam Vikas Y. Patade Penna Suprasanna 《Genetic Resources and Crop Evolution》2009,56(5):705-717
Sesuvium portulacastrum L. (seapurslane) is a halophyte used as pioneer species in sand dune fixation and stabilization of saline soil. Studies on
the morphological and molecular diversity were carried out for the 14 clones of Sesuvium collected from the different coastal regions of India. Significant differences were observed for morphological traits viz.,
length, width, diameter and area of leaf, internodal distance and stem diameter for different clones when compared with the
clone from Gujarat state (GJ1). A UPGMA dendrogram for morphological traits based on the Pearson’s similarity coefficient
clustered the clones into three groups considering 80% polymorphism as criteria. Molecular diversity among the clones was
studied using Randomly Amplified Polymorphic DNA (RAPD), Internal Transcribed Spacer (ITS) and markers specific to Ac homologous region. Of the total 749 RAPD loci amplified with 70 random primers, 294 were polymorphic with 39.25% diversity.
A phylogenetic tree constructed with UPGMA and SHAN, grouped the clones into three major clades based on RAPD data. The molecular
diversity studied with ITS and markers specific to Ac homologous region revealed 37.50% and 66.66% polymorphism and clustered the clones into three and four clades, respectively.
The genetic diversity analysis revealed wide variations among the S. portulacastrum clones, reflecting a high level of diversity within the species which might be due to anthropogenic impact and geographic
environmental conditions. Further, the various clones from the different eco-geographic coastal localities might have originated
from native places of wild abundance. To the best of our knowledge, this is the first attempt to evaluate both morphological
and genetic diversity among the Sesuvium clones collected from the distant habitats of the coastal regions of the India. 相似文献
9.
Genetic Variation and Population Structure in a Eurasian Collection of <Emphasis Type="Italic">Isatis tinctoria</Emphasis> L. 总被引:2,自引:0,他引:2
Giorgia Spataro Paola Taviani Valeria Negri 《Genetic Resources and Crop Evolution》2007,54(3):573-584
Isatis tinctoria L. is a biennial species which was cultivated in Europe until the 18th century to produce indigo, a pigment used for dyestuffs.
Today there is renewed interest in this ancient crop because of a market demand for natural dyes. Cultivation of the species
appears to be particularly suitable for marginal areas. Information about the evolutionary and genetic patterns of I. tinctoria is needed if varieties or to be developed in future breeding programs. The aim of this study was to assess the genetic variation
and similarity levels among and within natural populations of I. tinctoria from Europe and central Asia. Fifteen populations were used to carry out the genetic analyses with AFLP and SAMPL molecular
markers. Data collected were analysed by the UPGMA method and were used to perform AMOVA. The results are consistent with
the hypothesis that the crop originated in an eastern centre of origin and moved westward giving rise to a gene pool that
is quite different from the original. The wide within-population variation revealed by this study suggests that effective
breeding work to develop varieties suitable for marginal environments can be carried out easily. 相似文献
10.
Gemechu Keneni Mussa Jarso Tezera Wolabu Getnet Dino 《Genetic Resources and Crop Evolution》2005,52(5):551-561
A field experiment was conducted in 2001 at Holetta and Kulumsa, Ethiopia, to study genetic diversity in Ethiopian faba bean
(Vicia faba L.) landraces. One hundred sixty random germplasm accessions were grown in an alpha lattice design with two replications. Data
on 12 traits were collected and analyzed. Significant differences were observed among the accessions for most of the traits
(except number of pods/podding nodes) at each location even though differences pooled over location were mostly non-significant.
Cluster analysis distinguished seven diversity classes of different sizes. Accessions from the northern half of the country
(North and South Wello, North Gonder and North Shewa) were closely related while those from the southern part of the country
(Arsi) were highly diverse. Cumulative effects of a number of characters dictated differentiation of the accessions into clusters.
Some overlapping were encountered between accessions from the northern and those from the southern parts of the country. The
study revealed that accessions from different regions might have similar genetic background and those from the same origin
might also have different genetic background. Therefore, geographic diversity should not necessarily be used as an index of
genetic diversity and parental selection should be based on a systematic study of genetic diversity in a specific population.
Genetic distances between most of the clusters were significant that crosses between parents selected out of them are expected
to generate desirable progenies. Future germplasm collection, conservation and utilization strategies should put more focus
not only on inter-regional diversity in the country as a whole but also on intra-regional diversity in Arsi. 相似文献
11.
Mehboob-ur-Rahman Tahira Yasmin Nabila Tabbasam Ihsan Ullah Muhammad Asif Yusuf Zafar 《Genetic Resources and Crop Evolution》2008,55(3):331-339
Genetic diversity is an area of concern for sustaining crop yield. Information on genetic relatedness/diversity among Gossypium arboreum L. cultivars/genotypes is scanty. We have used random amplified polymorphic DNA (RAPD) analysis to assess the genetic divergence/relationship
among 30 genotypes/cultivars of G. arboreum. Of 45 primers surveyed, 63% were polymorphic. Out of the total number of loci amplified, 36% were polymorphic. The calculated
genetic similarity between the cultivars/genotypes was in the range of 47.05–98.73%. Two genotypes, HK-244 and Entry-17, were
the most distantly related. The average genetic relatedness among all the genotypes was 80.46%. However, most of the cultivated
varieties showed a close genetic relationship, indicating a narrow genetic base in comparison to the non-cultivated germplasm.
The calculated coefficients were used to construct a dendrogram using the unweighted pair group of arithmetic means (UPGMA)
algorithm, which grouped the genotypes/cultivars into two major and three smaller clusters. The study is the first comprehensive
analysis of the genetic diversity of G. arboreum germplasm and identifies cultivars that will be useful in extending the genetic diversity of cultivated varieties and future
genome mapping projects. 相似文献
12.
13.
C. Tara Satyavathi K. V. Bhat C. Bharadwaj S. P. Tiwari V. K. Chaudhury 《Genetic Resources and Crop Evolution》2006,53(5):1069-1079
AFLP technique was used to assess genetic diversity in 72 soybean varieties under cultivation in India. Selected 12 AFLP primer
pairs produced 1319 products of which 1257 were polymorphic (95%). Wide variations were observed for the number of amplification
products, percent polymorphism and average polymorphism information content (PIC). The Jaccard's similarity indices (J) based on the AFLP profiles of the 72 soybean varieties were subjected to UPGMA cluster analysis. The dendrogram generated
revealed four major clusters, which were strongly supported by the high bootstrap values obtained from analyses of 1000 bootstrap
samples. In addition, the Mantel's test for cophenetic correlation with r = 0.955 indicated very good fit of the varieties to a group in the cluster analysis. Some correspondence between the clustering
pattern and the pedigree, place of release or target area of the variety was observed. Overall moderately high genetic diversity
was observed which appears to be due to the higher genetic diversity prevalent in 12 of the varieties included in three diverse
clusters and was indicative of the need to include more diverse germplasm in the soybean improvement programs. 相似文献
14.
Toan Duc Pham Tri Minh Bui Gun Werlemark Tuyen Cach Bui Arnulf Merker Anders S. Carlsson 《Genetic Resources and Crop Evolution》2009,56(5):679-690
Sesame (Sesamum indicum L.) is a traditional oil crop cultivated throughout South East Asia. To estimate the genetic diversity of this crop in parts
at the region, 22 sesame accessions collected in Vietnam and Cambodia were analyzed using 10 RAPD markers. The 10 primers
generated 107 amplification products of which 88 were polymorphic fragments (83%). Genetic diversity of all populations was
Ht = 0.34 when estimated by Nei’s genetic diversity and species diversity was H′sp = 0.513 when estimated by Shannon diversity index. Genetic distance ranged from 0.03 to 0.43, with a mean genetic distance
of 0.23. The unweighted pair group method with arithmetic averages (UPGMA) cluster analysis for the 22 accessions divided
the material in four groups. The dendrogram revealed a clear division among the sesame accessions based on their geographical
region. Interestingly, some geographically distant accessions clustered in the same group, which might indicate the human
factor involved in the spreading of sesame varieties. The high level of polymorphism shown suggests that RAPD techniques can
also be useful for the selection of parents in sesame (Sesamum indicum L.) breeding program and for cultivar differentiation. 相似文献
15.
Gemechu Keneni Mussa Jarso Tezera Wolabu Getnet Dino 《Genetic Resources and Crop Evolution》2005,52(5):539-549
An experiment was conducted in 2001 at Holetta and Kulumsa, Ethiopia, to study the extent and pattern of genetic diversity
in Ethiopian field pea (Pisum sativum L.) landraces. One hundred forty-eight germplasm accessions were grown in an alpha lattice design with 2 replications. Data
on 12 traits were collected and analyzed. Differences among the accessions were significant for most of the traits (except
number of seeds/ pod) at each location even though differences pooled over location were mostly non-significant. The accessions
were grouped into five clusters of different sizes. Accessions from the southern part of the country (Arsi) distributed overall
clusters while those from the northern half (North and South Wello, North Gonder and North Shewa) fell into clusters C1 to C3. Cumulative effects of a number of characters dictated differentiation of the accessions into clusters. There was no definite
relationship between geographic diversity and genetic diversity as overlapping was encountered in clustering pattern among
accessions from different parts of the country. Accessions from different regions might have similar genetic background and
those from the same origin might also have different genetic background. Therefore, geographic diversity should not necessarily
be used as an index of genetic diversity and parental selection should be based on a systematic study of genetic diversity
in a specific population. Genetic distances among most of the clusters were significant that crosses between parents selected
out of them are expected to generate desirable genetic recombination. Selection should also consider the special advantages
of each cluster and each accession within a cluster. Future germplasm collection, conservation and breeding efforts should
focus not only on inter-regional diversity but also on intra-regional diversity. 相似文献
16.
Makiko Mimura Clarice J. Coyne Marie W. Bambuck Thomas A. Lumpkin 《Genetic Resources and Crop Evolution》2007,54(3):497-508
Edamame [Glycine max (L.) Merr.] is a type of soybean selected for fresh or frozen vegetable use at an immature stage. Since edamame has a similar
protein content, milder flavor, nuttier texture, and is easier to cook when compared to grain soybean, it is being promoted
as a new vegetable for global consumption. Global production will require breeding programs for local adaptation; however,
limited research has been published on genetic diversity of edamame varieties for the assessment of genetic resources. Simple
sequence repeats (SSRs) were used to study the genetic diversity among 130 accessions, including edamame cultivars and landraces
from Japan, China and the US, and also the new breeding lines in the US. Although it is assumed that elite edamame cultivars
would have narrow genetic diversity, seventeen SSRs detected polymorphism to distinguish 99 of the 130 accessions. The cluster
analysis generated nine clusters and 18 outliers. Genetic diversity within Japanese edamame was lower than that within Chinese
vegetable soybean accessions (maodou), even though only 10 Chinese maodou were analyzed compared to 107 Japanese edamame.
Cluster analysis revealed that the patterns of SSR diversity in edamame can generally distinguish maturity classes and testa
color. We concluded that Japanese edamame have a narrow genetic base different from others and that SSRs can describe the
patterns of genetic diversity among the elite vegetable soybean. 相似文献
17.
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
18.
Mohammad Moghaddam Bahman Ehdaie J. Giles Waines 《Genetic Resources and Crop Evolution》2000,47(3):323-334
Genetic variation and its distribution within and among 23 populations of Triticum urartu collected from Syria, Lebanon, Turkey, Armenia, and Iran was estimated using isozyme markers at eight polymorphic loci. The number of alleles per locus (A= 1.21), percentage polymorphic loci (P= 20.1%), and mean gene diversity (He= 0.024) were relatively low. In a population from Lebanon, a high number of alleles per locus (A= 2.13) and percentage polymorphic loci (P= 87.5%) was found. On average, genetic variation among populations (GST= 0.407) was smaller than within-population variation (0.593). However, different patterns of genetic structure were found among various geographic regions. Interpopulation variation was highest for the Iranian populations (0.89) followed by the Turkish populations (0.66). A reverse pattern was observed for the Syrian (0.11) and for the Lebanese (0.13) populations. The Armenian populations exhibited similar interpopulation and within-population variation. Principal component and cluster analyses resulted in distinct grouping of the geographically proximal populations, with the exception of the two Iranian populations. The Turkish populations were different from the neighboring Armenian populations compared to other countries. The populations from southern Syria and those from Lebanon also exhibited a high degree of genetic diversity. The two most heterozygous loci, Mdh-2 and Pgi-2, separated the populations along the first and second principal components, respectively. Most of the rare alleles were scattered sporadically throughout the geographic regions. Rare alleles with high frequencies were found in the Turkish and Armenian populations. These results indicated that different geographic regions require specific sampling procedures in order to capture the range of genetic variation observed in T. urartu populations. 相似文献
19.
Hironori Katayama Shiho Adachi Toshiya Yamamoto Chiyomi Uematsu 《Genetic Resources and Crop Evolution》2007,54(7):1573-1585
Iwateyamanashi (Pyrus ussuriensis var. aromatica) is one of the Pyrus species which grows wild in Japan. The number of Iwateyamanashi trees has been decreasing, so conservation and evaluation
is urgently needed. Over 500 accessions of Pyrus species collected from Iwate in northern Tohoku region are maintained at Kobe University as an Iwateyamanashi germplasm collection.
In order to investigate the genetic diversity, five SSR (simple sequence repeat) markers, developed from Japanese and European
pear were examined for 86 Pyrus individuals including 58 accessions from Iwate. These SSR loci could discriminate between all the Iwate accessions except
for 10 that bear seedless fruit, as well as determine the genetic diversity in Iwateyamanashi germplasms. High levels of variation
were detected in 41 alleles and the mean observed heterozygosity across 5 loci was 0.50 for the Iwate accessions. Seedless
accessions sharing identical SSR genotype with the local pear variety “Iwatetanenashi” were supposed to have been propagated
vegetatively via grafting. In an UPGMA phenogram, Japanese pear varieties (P. pyrifolia) were clustered into two groups with some Iwate accessions including seedless ones. Another 38 Iwate accessions were not
clustered clearly, and there was no clear relationship between these accessions and geographical distribution or morphological
characters. Allele frequency revealed that the Iwate accessions were genetically more divergent than the Japanese pear varieties.
Most Japanese pears possessed a 219 bp deletion at a spacer region between the accD and psaI genes in the chloroplast DNA (cpDNA), but other Pyrus species and two Iwateyamanashi trees did not. In the Iwate accessions, 79.3% had a deletion type cpDNA and others had a standard
type cpDNA without deletion. These results are indicative of the wide range of genetic diversity in the Iwate accessions which
include Japanese pear varieties. A combination of SSR and cpDNA analyses revealed high heterogeneity in Iwateyamanashi and
coexistence of Iwateyamanashi and hybrid progeny with P. pyrifolia. These could be reasons for the wide range of continuous morphological variation described previously. 相似文献
20.
Hojjatollah Saeidi Badradin Ebrahim Sayed Tabatabaei Mehdi Rahimmalek Majid Talebi-Badaf Mohammad Reza Rahiminejad 《Genetic Resources and Crop Evolution》2008,55(8):1231-1238
The diploid goatgrass Aegilops
tauschii is considered the D-genome donor of bread wheat and has probably a centre of diversity in north of Iran. In order to measure
the genetic diversity of and the relationships among different populations, varieties and subspecies belonging to Ae. tauschii in Iran, DNA was extracted from 48 accessions of Ae. tauschii collected across the geographic range of the species in the Country and the genetic diversity was assessed using AFLPs based
on eight PstI/MseI +3 primer pairs resulted in 277 bands, 198 of which were polymorphic. High level polymorphism was detected, with an average
of polymorphism rate of 0.715; relatively low genetic similarity (0.455) between accessions and significant difference between
the lowest (0.179) and the highest genetic similarity (0.817). The Iranian Ae. tauschii populations showed high level of genetic diversity. The populations studied were divided into two groups: one group was mainly
representing Northern populations collected from Southern Caspian Sea shore and the other group was mainly representing Northeast
and Northwest populations. Based on the results of this study, it can be suggested that Ae. tauschii possesses two separate gene-pools in Iran: Northern and Northeastern–Northwestern. Considering the needs for introducing
new characteristics and alleles for wheat improvement purposes, Ae. tauschii Iranian gene-pool is assumed to be of high importance for more investigation in the future. 相似文献