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1.
Temporal variation of diversity in Italian durum wheat germplasm 总被引:1,自引:0,他引:1
Giovanni Figliuolo Mariarosaria Mazzeo Ivana Greco 《Genetic Resources and Crop Evolution》2007,54(3):615-626
The aim of this work is to analyse the temporal change of genetic diversity in Italian durum wheat germplasm. The germplasm
deployed in this study (158 accessions), belonging to 5 different historical classes, was characterised for its microsatellite
and gliadin markers. The level of genetic diversity (He), based on gliadin and SSR markers results – on average – greater in indigenous landraces present in Italy before 1915, with
the exception of pure line material which had been selected from landraces (showing highest level of heterozigosity for gliadin
markers). Genotypes obtained from crosses or mutagenesis (referring to the 1950–1960 period) along with those resulting from
crosses between CIMMYT lines and old materials (1970s and beyond) were also genetically more diverse. Forty-nine percent of
indigenous landraces were genetically heterogeneous. Nine out of 53 landrace accessions were able to capture 4 different SSR
private alleles. It is speculated that the reduction of allele richness is an indicator of the genetic erosion of the pre-breeding
germplasm and it is pointed out that the implementation of appropriate methods of genetic conservation of this germplasm is
a priority for breeding and food safety. 相似文献
2.
Sukyeung Lee Yu-Mi Choi Myung-Chul Lee Do Yoon Hyun Sejong Oh Yeonju Jung 《Genetic Resources and Crop Evolution》2018,65(6):1591-1602
Glutenin largely determines wheat bread baking quality. As high-molecular-weight glutenin subunit (HMW-GS), related to Glu-1 loci, determines wheat flour elasticity, it correlates strongly with bread-making quality. This study was aimed at clarifying genetic variations in bread-making characteristics between East and West Asian wheat landrace germplasms, by investigating HMW-GS allelic composition of 1068 wheat accessions. Herein, the accession number having reported HMW-GS pattern in previous studies was 855. However, the accession number with newly detected HMW-GS patterns was 114. These new HMW-GS patterns were classified into 4 types based on similarity. Eight Korean accessions with these four types were identified. Concerning landrace germplasm nature, 99 accessions showed heterogeneous patterns caused by seed mixture. The Glu-1 loci allelic variation analysis, revealed that the percentages of Glu-A1c (73.6%), Glu-B1b (60.2%), and Glu-D1a (68.5%) were highest at Glu-A1, Glu-B1, and Glu-D1 loci, respectively. The incidence of preferable alleles for bread baking was high in Chinese accessions. In bread-making quality evaluation using Glu-1 score, 24 among 35 accessions with full score were from China. The polymorphic information content index of each origin based on HMW glutenin subunit combination showed that West Asian and neighboring-regional landraces, excluding Afghanistan ones, were more diverse than East Asian landraces excluding Chinese ones. Cluster analysis based on Glu-1 allelic combination showed that many Korean, Japanese, and Afghan accessions were in the same group. However, many Chinese and other West Asian accessions were in the other group despite geographical distance. 相似文献
3.
Evaluation of genetic diversity of bread wheat landraces from Pakistan by AFLP and implications for a future collection strategy 总被引:1,自引:0,他引:1
Ryoko Hirano Akira Kikuchi Makoto Kawase Kazuo N. Watanabe 《Genetic Resources and Crop Evolution》2008,55(7):1007-1015
We used amplified-fragment-length polymorphism (AFLP) markers to evaluate genetic variation in a set of bread wheat (Triticum aestivum L.) landraces and improved materials. Landraces collected from different geographic and agro-ecological zones in Pakistan
in 1987, 1989 and 1991 were separated into two groups based on their geographic origins: northern (Himalaya) and south-western
(Balochistan) Pakistan. Six AFLP primer combinations detected 453 AFLP markers in the 43 landrace accessions and four high-yield
varieties (HYVs). Of these, 225 (49.67%) were rare (shared with < 5% of all accessions). Among these rare alleles, 23 (10.22%)
were common in the Himalaya (shared with > 10% of accessions collected there) but were not found in Balochistan. We conclude
that there is a higher probability of collecting rare alleles at overall, but which are in contrast locally common ones in
the Himalayan region. Gene diversity was 0.17 in the Himalayan group and 0.15 in the Balochistan group. Considerable genetic
variability was found in both groups. Accessions from different agro-ecological zones were indistinguishable by cluster analysis,
indicating intensive seed trading within the country. Cluster analysis indicated that the landraces and the HYVs are genetically
distinct; suggesting that genetic erosion of wheat landraces has been unlikely taken in place. This study provides an example
of how analysis of existing materials and data, can serve as a basis for future collection planning and conservation policies. 相似文献
4.
Genetic Diversity and Relationships of Wheat Landraces from Oman Investigated with SSR Markers 总被引:4,自引:3,他引:4
P. Zhang S. Dreisigacker A. Buerkert S. Alkhanjari A. E. Melchinger M. L. Warburton 《Genetic Resources and Crop Evolution》2006,53(7):1351-1360
Little is known about genetic diversity and geographic origin of wheat landraces from Oman, an ancient area of wheat cultivation.
The objectives of this study were to investigate the genetic relationships and levels of diversity of six wheat landraces
collected in Oman with a set of 30 evenly distributed SSR markers. The total gene diversity, (HT), conserved in the three durum wheat (Triticum durum desf.) landraces (HT = 0.46) was higher than in the three bread wheat (Triticum aestivum L.) landraces (HT = 0.37), which were similar to Turkish and Mexican bread wheat landraces calculated in previous studies. Genetic variation
partitioning (GST) showed that variation was mainly distributed within rather than among the durum (GST = 0.30) and bread wheat (GST = 0.19) landraces. Based on modified Rogers’ distance (MRD), the durum and bread wheat landraces were distinct from each
other except for a few individuals according to principal coordinate analysis (PCoA). One bread wheat landrace (Greda) was
separated into two distinct sub-populations. A joint cluster analysis with other landraces of worldwide origin revealed that
Omani bread wheat landraces were different from other landraces. However, two landraces from Pakistan were grouped somewhat
closer to Omani landraces indicating a possible, previously unknown relationship. Implications of these results for future
wheat landrace collection, evaluation and conservation are discussed. 相似文献
5.
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
6.
Yvonne Lokko Alfred Dixon Sam Offei Eric Danquah Martin Fregene 《Genetic Resources and Crop Evolution》2006,53(7):1441-1453
A study was conducted to determine the extent of genetic diversity among African cassava (Manihot esculenta Crantz) accessions resistant to the cassava mosaic virus disease (CMD), using simple sequence repeat (SSR) markers. The accessions
included a breeding stock (clone 58308), five improved lines, 62 CMD resistant and 10 CMD susceptible landraces. Genetic diversity
was assessed among accessions in five cluster groups derived from UPGMA analysis on data from 18 SSR primer pairs. Average
gene diversity, He, was high in all cluster groups, with an average heterozygosity of 0.591 ± 0.061. The estimator of inbreeding
Fis revealed a low level of inbreeding within groups and averaged −0.262 ± 0.142. Gene diversity among all accessions was
51.4% and gene diversity within cluster groups was 46.6%, while 4.8% was due to diversity between the different cluster groups.
The amount of genetic differentiation measured by Gst and Fst were 9.6% and 12.1% respectively, indicating a weak genetic
structure. 相似文献
7.
P. Routray O. Basha M. Garg N. K. Singh H. S. Dhaliwal 《Genetic Resources and Crop Evolution》2007,54(6):1315-1326
Seed samples of 27 landraces of wheat were collected from farmers’ fields of hilly areas of Himalaya in Uttaranchal state
of India during April 2004. Genetic diversity among 41 genotypes (cultivars and landraces of wheat) was studied using morphological
traits, microsatellite markers and SDS-PAGE of HMW-GS. The dendrogram and PCA (Principal Component Analysis) based on morphological
data clearly separated landraces of wheat from cultivars. In the dendrogram based on microsatellite markers data all the wheat
cultivars released after the introduction of high yielding dwarf wheat varieties from CIMMYT, used in this study, were grouped
separately with the exception of NP4. The pre-green revolution indigenous varieties grouped with landraces suggesting that
the same had been probably developed through selection among landraces in India. The landraces had higher diversity for HMW-glutenin
subunits coded by Glu-B1, with distinct subunit combinations 6 + 8, 7 + 9, 13 + 16, than within the wheat cultivars analyzed. Most of the landraces
except IITR10 and IITR14 are clearly distinct from the indigenous and modern wheat cultivars released in India in the 20th
century. More than half of the landraces were heterogeneous mixture of plants with different glume color, awnness, grain color
and HMW-GS profile and hence need purification through single plant selection. Some of the landraces with resistance to yellow
rust and powdery mildew and distinct HMW-GS subunits can be used in appropriate breeding programs. It will be desirable to
conserve and protect the landraces as geographical indications of Uttaranchal. 相似文献
8.
S. Al Khanjari K. Hammer A. Buerkert M. S. Röder 《Genetic Resources and Crop Evolution》2007,54(6):1291-1300
Results of archaeological studies indicate a millennia-old cultivation history for wheat (Triticum spp.) in Oman. However, in spite of numerous collection surveys and efforts for phenotypic characterization of Omani wheat
landraces, no attempts have been made using molecular tools to characterize this germplasm. To fill this gap, 29 microsatellite
markers revealing 30 loci were used to study the genetic diversity of 38 tetraploid wheat landrace accessions comprising the
species T. dicoccon, T. durum and T. aethiopicum. A total of 219 alleles were detected whereby the number of alleles per locus ranged from 2 to 16 with an average number
of 7.1 alleles per locus. The highest number of alleles occurred in the B genome with on average 7.9 alleles per locus as
compared to the A genome with 6.5 alleles per locus. Heterogeneity was detected for all microsatellites except for GWM 312, GWM 601 and GWM 192B with an average heterogeneity over all primers and lines of 14.4%. Approximately 10% of the accessions contained rare alleles
with an average allele frequency <4%. Gene diversity across microsatellite loci ranged from 0.26 to 0.85. The pairwise comparison
of genetic similarity ranged from 0.03 to 0.91 with an average of 0.2. Cluster analysis revealed a clear separation of the
two species groups T. dicoccon versus T. durum and T. aethiopicum. Within the species clusters regional patterns of subclustering were observed. Overall, this study confirmed the existence
of a surprisingly high amount of genetic diversity in Omani wheat landraces as already concluded from previous morphological
analyses and showed that SSR markers can be used for landraces’ analysis and a more detailed diversity evaluation. 相似文献
9.
Jemanesh K. Haile Karl Hammer Ayele Badebo Miloudi M. Nachit Marion S. Röder 《Genetic Resources and Crop Evolution》2013,60(2):513-527
A set of 77 markers was used to describe the genetic diversity in a group of 58 tetraploid wheat accessions. Analysis was performed using 31 neutral SSR markers, 31 SSR/STS markers linked with reported major stem rust resistance genes and 15 SSR markers linked with QTL identified for resistance to Ethiopian stem rust races of Puccinia graminis Pers. f. sp. tritici Eriks. et E. Henn. (Pgt),including Ug99. The material consisted of 32 (Triticum durum s.l. incl. T. aethiopicum Jakubz., Triticum turgidum and Triticum polonicum) landraces and 22 registered T. durum varieties from Ethiopia that were released 1966–2009 and four T. durum varieties from ICARDA. A total of 720 alleles were detected. Considering the three marker sets, the mean number of alleles was higher for major stem rust resistance gene linked markers (9.9) followed by neutral SSR markers (9.2) and markers linked with QTL for stem rust resistance (8.5). Dendrograms derived from UPGMA analysis grouped the accessions into two major clusters. The principal component analysis based on the combination of the three marker sets formed three groups. The 1st group was composed of all the improved varieties, whereas the 2nd and the 3rd group contained the landraces. All the landraces that formed the 3rd group were susceptible to Ethiopian stem rust races of Pgt including Ug99. The information on the extent of the genetic diversity of the improved varieties obtained in this investigation will be helpful for developing appropriate breeding strategies to broadening the genetic base of durum wheat varieties in further breeding programmes. 相似文献
10.
11.
T. W. Eschholz P. Stamp R. Peter J. Leipner A. Hund 《Genetic Resources and Crop Evolution》2010,57(1):71-84
Between 1930 and 2003 with emphasis on the 1940s maize landraces (Zea mays L. ssp. mays) from all over Switzerland were collected for maintenance and further use in a new Swiss breeding program. The genetic relationship
and diversity among these accessions stored in the Swiss gene bank is largely unknown. Our hypothesis was that due to the
unique geographic, climatic, and cultural diversity in Switzerland a diverse population of maize landraces had developed over
the past three centuries. The aims were to characterize the genetic diversity of the Swiss landraces and their genetic relationship
with accessions from neighbouring regions as well as reviewing their history, collection, and maintenance. The characterization
and grouping was based on analyses with ten microsatellite markers. Geographic, cultural, and climatic conditions explained
a division in two distinct groups of accessions. One group consisted of landraces collected in the southern parts of Switzerland.
This group was related to the Italian Orange Flints. The other group contained accessions from northern Switzerland which
were related to Northern European Flints in particular German Flints. Historic evidence was found for a frequent exchange
of landraces within the country resulting in a lack of region-specific or landrace-specific genetic groups. The relatively
large separation between the accessions, indicated by high F
ST (0.42), might be explained partly by a bottleneck during the collection and maintenance phase as well as by geographical
and cultural separation of north and south of the country. Due to the high genetic diversity, the accessions here are a potential
resource for broadening the European flint pool. 相似文献
12.
Ganka Ganeva Victor Korzun Svetlana Landjeva Zaprjanka Popova Nikolai K. Christov 《Genetic Resources and Crop Evolution》2010,57(2):273-285
The genetic diversity in a Triticum durum Desf. collection, consisting of 102 Bulgarian landraces, nine Bulgarian and 25 introduced cultivars was studied using 14
highly polymorphic microsatellite markers. A total of 100 alleles were identified, with an average of 7.14 alleles per marker.
The gene diversity values (He) of the markers for the total samples ranged from 0.23 (WMS357 and WMS631) to 0.77 (WMS46),
with an average of 0.52. Within the landraces that were collected from 18 sites in Southern Bulgaria showed 2–11 alleles per
locus with an average of 6.07. The microsatellite analysis suggests that the genetic diversity among landraces is lower compared
to the diversity levels for durum wheat in countries close to the main centers of wheat domestication. Breeding activities
have caused significant reduction of the allelic polymorphism, elimination of rare alleles, and increase in the number of
common alleles and the frequency of dominating alleles. 相似文献
13.
Farzad Fayaz Mohsen Mardi Mostafa Aghaee Farrokh Darvish Reza Talebi 《Archives of Agronomy and Soil Science》2013,59(10):1339-1357
This study was undertaken to compare patterns of agronomic characters and yellow pigment content diversity between Iranian durum landraces and modern varieties. In four field experiments, a collection of 127 accessions of landraces and 23 modern cultivars tetraploid wheat representing Iranian and global genetic diversity were tested under optimum and rain-fed conditions. Across the environments, the yellow pigment concentrations ranged from 1.85 mg kg?1 to 8.95 mg kg?1 in the field-grown samples. Multivariate analysis detected five groups, four including landraces and one comprising modern cultivars. As a group, modern cultivars were the most productive and showed high mean values for harvest index, grains per spike and yellow pigment, but they had the lowest plant height. Landraces had the highest mean number of spikes per m2 and 1000-kernel weight, but were characterized by low plant height and yellow pigment content. Clustering analysis also showed that, based on yield and yellow pigment content, the accessions in different groups were of different origins, suggesting that there was no clear relationship between accessions and geographical diversity. According to our results, Iranian landraces can be particularly useful as germplasm in breeding programmes to improve spikes per m2 and 1000-kernel weights. 相似文献
14.
15.
Stina Christensen Roland von Bothmer Gert Poulsen Lorenzo Maggioni Marianne Phillip Bente Anni Andersen Rikke Bagger Jørgensen 《Genetic Resources and Crop Evolution》2011,58(5):657-666
AFLP markers were used to characterize diversity and asses the genetic structure among 17 accessions of kale landraces, cultivars
and wild populations from Europe. The range of average gene diversity in accessions was 0.11–0.27. Several landraces showed
higher levels of diversity than the wild populations and one cultivar had the lowest diversity measures. The landraces that
were most genetically diverse were from areas where kales are known to be extensively grown, suggesting in situ conservation in these areas as a supplement to storage of seeds in gene banks. An analysis of molecular variance (AMOVA)
showed that 62% of the total variation was found within accessions. For most accessions, genetic distance was not related
to geographic distance. Similarities among accessions were probably not caused by recent gene flow since they were widely
separated geographically; more likely the relationship among them is due to seed dispersal through human interactions. Our
results indicate that a kale population found in a natural habitat in Denmark was probably not truly wild but most likely
an escape from a cultivated Danish kale that had subsequently become naturalized. 相似文献
16.
Naoki Yamanaka Masrom Hasran Dong He Xu Hiroshi Tsunematsu Salma Idris Tomohiro Ban 《Genetic Resources and Crop Evolution》2006,53(5):949-954
We used AFLP analysis to explore the genetic relationship and diversity between and within 4 Mangifera species. We analyzed 35 accessions comprising 8 cultivars and 3 landraces of M. indica L., 11 landraces of M. odorata Griff., 7 landraces of M. foetida Lour., and 6 landraces of M. caesia Jack. Using 8 primer combinations produced a total of 518 bands, 499 (96.3%) of which were polymorphic among the 35 accessions.
Clustering analysis showed that all 35 accessions were basically classified into 4 groups corresponding to the 4 Mangifera species. Our results indicate that the genetic relationship of these 4 Mangifera species based on AFLP analysis is in good agreement with their classification by classic methods. In addition, it was clearly
revealed the genetic diversity between and within 4 Mangifera species. The findings obtained in this study are useful for the breeding in Mangifera species. 相似文献
17.
Ethiopia is a centre of diversity and hosts rich genetic resources of tetraploid wheats. Through time, the wheat materials
were subject to genetic erosion. Closer investigation was made to assess the status of loss, and identify the possible causes
by studying two districts from East Shewa. Information from primary and secondary sources was reviewed and analysed. Farmers
identified 26 tetraploid wheat landraces (21 from Akaki and 17 from Ejere), which were once widely grown in the area. Of these,
only six were currently available. Compared to the formerly available number of landraces, the loss of diversity in the study
area was estimated to be 77%. In the Ejere locality, the loss was 100% before the launching of the on farm landrace conservation
programme, and for Akaki it was 95%. Major factors that contributed to the loss include: (1) introduction and expansion of
bread wheat varieties; (2) expansion of tef; (3) lack of a mechanism to re-supply seeds of tetraploid wheat landraces; (4)
decline in size of landholdings; (5) changes in land use and cropping patterns; (6) lack of policy support; and (7) expansion
of improved tetraploid wheat varieties. The lessons from this study underscore the importance of strengthening the local seed
supply system as a prerequisite for sustaining on farm conservation of landraces. Moreover, it is necessary to initiate diversity
studies focusing on the distribution and status of tetraploid wheat landraces across the country. Complementing these by molecular
analyses is essential in order to assess the genetic distinctness of the landraces. 相似文献
18.
More than 100?years ago, before the rediscovery of Mendel’s laws of inheritance, Nazareno Strampelli started a deliberate crossing programme among Italian and foreign bread wheat genotypes that led to the constitution of over 100 varieties and allowed Italy to significantly increase wheat production. Several varieties enjoyed worldwide popularity and were instrumental in the success of many other breeding programmes. To better understand the reasons of these accomplishments, 84 accessions, representing 50 Strampelli varieties, were characterized for glutenin storage proteins and AFLP patterns, in order to confirm their identification and to assess their genetic diversity. The molecular markers analysis confirmed the correct attribution of most accessions and highlighted the broad genetic variation existing among Stampelli’s varieties. Some genotypes, deemed incompatible with the available pedigree data, were removed from the final analysis. A limited within-variety diversity among genotypes was probably due to incomplete homogeneity and stability of Strampelli materials, but also to the use of heterogeneous local populations as parents. 相似文献
19.
Angela R. Piergiovanni 《Genetic Resources and Crop Evolution》2013,60(1):325-333
The increasing consumers’ request for new speciality wheat derivatives and the possible widening of marketing opportunities is giving to both landraces and old varieties, new chance of on farm survival providing a low cost way to safeguard these important genetic resources. A farmer’s consortium acting in north-western Italy, is attempting the introduction of some old bread wheat landraces in marginal environments of Piedmont and Liguria regions. The reason of this attempt is the local market demand of old bread varieties suitable for the preparation of traditional cakes and biscuits. Three Italian bread wheat landraces, a mixture of durum and bread wheat landraces and three modern varieties were evaluated. The entries were cropped in Val Borbera and Val d’Aveto (Piedmont and Liguria region, respectively) in the same growing season (2009–2010). The high variation of gliadin profile detected within the landraces indicates that all have retained the genetic heterogeneity typical of the old wheat landraces. In consequence of the health-promoting effects of whole grain consumption, eleven nutritional and technological traits of whole flours were investigated. The analysis of collected data revealed appreciable differences among the flours obtained from the landraces and the modern varieties. These differences can be mainly attributed to the intensive breeding carried out on bread wheat in the last century. The results of this study suggest that the old bread wheat landraces could have good chance of survive on farm when their characteristics fulfil the requirements of local communities. 相似文献
20.
Antonio M. De Ron María C. Menéndez-Sevillano Marta Santalla 《Genetic Resources and Crop Evolution》2005,51(8):883-894
The phenotypic variation found in four common bean (Phaseolus vulgaris L.) complex primitive landraces, among a group of accessions collected in Northwestern Argentina in several missions is described, with particular attention to the wide diversity found in some small areas. It is presented a hypothesis about the maintenance of such diversity in bean mixtures or complex primitive landraces that grow close to their wild relative. Wide diversity regarding to seed type and plant characteristics was displayed by the landraces MCM-SV (composed of 11 lines), MCM-292 (14 lines), MCM-298 (5 lines) and VAV-3716 (14 lines). Food uses of dry seed and fresh pod seemed to be more relevant than the aesthetic use although all of them were presumably considered by humans for centuries resulting in the current phenotypes of these complex primitive landraces. Additionally, some weedy types (intermediate between wild and domesticated types) were detected in the landracesMCM-292 and MCM-298. The four complex landraces described consisted of highly diverse mixtures and they could play a role in breeding to enlarge the genetic basis of domesticated bean varieties belonging to the Andean gene pool. 相似文献