共查询到20条相似文献,搜索用时 140 毫秒
1.
Dobrovolskaya O Saleh U Malysheva-Otto L Röder MS Börner A 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2005,111(7):1322-1329
In total 70 genebank accessions comprising 50 hexaploid, 12 tetraploid and 8 diploid wheats of the Gatersleben collection
were selected based on the screening of the passport data for identical cultivar names or accession numbers of the donor genebanks.
Twelve potential duplicate groups consisting of three to nine accessions with identical names/numbers were selected and analysed
with DNA markers (microsatellites). A bootstrap approach based on re-sampling of both microsatellite markers and alleles within
marker loci was used to test for homogeneity. Although several homogeneous groups were identified it became clear that cultivar
name identity alone did not allow the determination of duplicates. A combination of SSR-analysis followed by the bootstrap
method and database survey considering the botanical classification and other data (origin, growth habit and donor) available
is recommended in order to determine duplicates. A procedure for the identification of duplicates and their further handling
in ex situ genebanks is discussed. 相似文献
2.
P. Bertin D. Grégoire S. Massart D. de Froidmont 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(1):148-156
Spelt and common wheat constitute two of the six groups of the hexaploid wheats with an AABBDD genome. Spelt culture has been
progressively replaced by that of common wheat which out-yields spelt under high-input conditions. In the last decades, spelt
breeders intended to introduce the yield-potential and bread-making qualities of common wheat into spelt, by frequent crossings
between accessions of these two different groups. The present study aims at determining the genetic basis of modern spelt
cultivars in terms of intra-group variability and inter-group (spelt vs common wheat) distances, by using microsatellite markers
developed for common wheat. The allelic composition of 30 spelt and nine common wheat accessions was determined at 17 microsatellite
loci. The coefficient of co-ancestry (ƒ) and the genetic distances (1 - proportion of shared alleles) based upon allelic composition
were calculated for all pairs of accessions. Two dendrograms were constructed using the UPGMA method. Amplification products
were found for all loci on most accessions. A total of 113 alleles was identified, of which 60.2% were specific to spelt or
common wheat. The correlation between (1 –ƒ ) and the genetic distance was high (0.701***). The mean pairwise genetic distance
was 0.656 ± 0.181 over the 39 accessions, 0.706 ± 0.14 among common wheat and 0.573 ± 0.172 among spelt. The mean genetic
distance between spelt and wheat was 0.782 ± 0.113. The two dendrograms were in accordance with each other and clearly separated
the spelt from the common wheat accessions. It is concluded that microsatellites developed for common wheat and distances
based on the proportion of shared alleles are powerful tools for reconstructing phylogenies in spelt, and that the genetic
basis of modern spelt cultivars is narrow despite frequent crosses made with bread wheat.
Received: 26 January 2000 / Accepted: 26 May 2000 相似文献
3.
S. Siju K. Dhanya S. Syamkumar T.E. Sheeja B. Sasikumar A.I. Bhat V.A. Parthasarathy 《Biochemical Systematics and Ecology》2010
Development of a robust set of 18 genomic microsatellite markers from turmeric (Curcuma longa L.) and its effective utilization in estimating the genetic diversity of 20 turmeric accessions are described. A total of 103 alleles were detected with an average of 5.7 alleles per locus. These markers displayed varied levels of polymorphism as evident from its discriminating power ranging from 0.19 to 0.70. The UPGMA cluster analysis of genetic distance values resolved the 20 turmeric accessions into five main groups. Three sets of genetically identical accessions were detected within the analyzed accessions, suggesting a revisit of the germplasm collection strategy based on vernacular identity. The entire grouping pattern of the entities was loose and independent of their geographical origins. These polymorphic SSR markers would be useful for the population genetic studies and germplasm management of turmeric. 相似文献
4.
F. F. Fuentes E. A. Martinez P. V. Hinrichsen E. N. Jellen P. J. Maughan 《Conservation Genetics》2009,10(2):369-377
Quinoa (Chenopodium quinoa Willd.) is a staple seed crop in the Andean region of South America. Improving quinoa productivity is a primary food-security
issue for this region, and has been part of the impetus for the establishment of several new quinoa breeding programs throughout
the Andean region. Chilean quinoa has been characterized as morphologically diverse and bifurcated into coastal and highland
ecotypes. The success of emerging breeding programs will rely heavily on the development of core germplasm collections and
germplasm evaluation—especially of the coastal quinoa ecotypes that are often neglected in traditional breeding programs.
Thus, the objective of this study was to characterize and quantify the genetic diversity within 28 Altiplano and 31 coastal
Chilean accessions of quinoa using microsatellite markers. To facilitate the analysis, we also report the development of seven
sets of fluorescent multiplexed microsatellite PCR reactions that result in genetic information for 20 highly polymorphic
microsatellite loci. A total of 150 alleles were detected among the quinoa accession, ranging from 2 to 20 alleles per locus
and an average 7.5 allele/locus. Both cluster (UPGMA) and principal component analyses separated the accessions into two discrete
groups. The first group contained quinoa accessions from the north (Andean highlands) and the second group consisted of accessions
from the south (lowland or coastal). Three accessions from Europe were classified into the southern quinoa group. The data
obtained in the diversity analyses highlights the relationships within and among northern and southern Chilean quinoa accessions
and provides the quinoa scientific community with a new set of easy to use and highly informative genetic markers. 相似文献
5.
Young-Il Cho Jong-Hyun Park Chul-Won Lee Won-Hee Ra Jong-Wook Chung Jung-Ro Lee Kyung-Ho Ma Seok-Young Lee Kang-Seob Lee Myung-Chul Lee Yong-Jin Park 《Genes & genomics.》2011,33(2):187-195
Sixteen polymorphic microsatellite (SSR) markers, developed from an SSR-enriched genomic DNA library of sesame (Sesamum indicum L.), were used to assess genetic diversity, phylogenetic relationships, and population structure among 150 sesame accessions collected from 22 countries. A total of 121 alleles were detected among the sesame accessions. The number of detected alleles varied from 2 to 18, with an average of 7.6 alleles per locus. Polymorphism information content values ranged from 0.03 to 0.79, with an average of 0.42. These values indicated an excess of heterozygous individuals at 16 loci and an excess of homozygous individuals at three loci. Of these, 32 genotype-specific alleles were identified at 11 of 16 polymorphic SSR markers. Cluster analyses were performed by accession and population, revealing a complex accession distribution pattern with mean genetic similarity coefficient of 0.45 by accession and 0.52 by population. The wide variation in genetic similarity among the accessions revealed by SSRs reflected a high level of polymorphism at the DNA level. Model-based structure analysis revealed the presence of three groups that were basically consistent with the clustering results based on genetic distance. These findings may be used to augment the sesame germplasm and to increase the effectiveness of sesame breeding. 相似文献
6.
Genetic diversity in Elymus caninus as revealed by isozyme, RAPD, and microsatellite markers. 总被引:10,自引:0,他引:10
Genetic diversity of 33 Elymus caninus accessions was investigated using isozyme, RAPD, and microsatellite markers. The three assays differed in the amount of polymorphism detected. Microsatellites detected the highest polymorphism. Six microsatellite primer pairs generated a total of 74 polymorphic bands (alleles), with an average of 15.7 bands per primer pair. Three genetic similarity matrices were estimated based on band presence or absence. Genetic diversity trees (dendrograms) were derived from each marker technique, and compared using Mantel's test. The correlation coefficients were 0.204, 0.267, and 0.164 between isozyme and RAPD distance matrices, RAPD and microsatellite distance matrices, and between isozyme and microsatellite distance matrices, respectively. The three methodologies gave differing views of the amount of variation present but all showed a high level of genetic variation in E. caninus. The following points may be drawn from this study whether based on RAPD, microsatellite, or isozyme data: (i) The Icelandic populations are consistently revealed by the three dendrograms. The congruence of the discrimination of this accession group by RAPD, microsatellite, and isozyme markers suggests that geographic isolation strongly influenced the evolution of the populations; (ii) The degree of genetic variation within accessions was notably great; and (iii) The DNA-based markers will be the more useful ones in detecting genetic diversity in closely related accessions. In addition, a dendrogram, which took into account all fragments produced by isozymes, RAPDs, and microsatellites, reflected better the relationships than did dendrograms based on only one type of marker. 相似文献
7.
Marion S. Röder Jens Plaschke Susanne U. König Andreas Börner Mark E. Sorrells Steven D. Tanksley Martin W. Ganal 《Molecular & general genetics : MGG》1995,246(3):327-333
The potential of microsatellite sequences as genetic markers in hexaploid wheat (Triticum aestivum) was investigated with respect to their abundance, variability, chromosomal location and usefulness in related species. By screening a lambda phage library, the total number of (GA)n blocks was estimated to be 3.6 x 104 and the number of (GT)n blocks to be 2.3 x 104 per haploid wheat genome. This results in an average distance of approximately 270 kb between these two microsatellite types combined. Based on sequence analysis data from 70 isolated microsatellites, it was found that wheat microsatellites are relatively long containing up to 40 dinucleotide repeats. Of the tested primer pairs, 36% resulted in fragments with a size corresponding to the expected length of the sequenced microsatellite clone. The variability of 15 microsatellite markers was investigated on 18 wheat accessions. Significantly, more variation was detected with the microsatellite markers than with RFLP markers with, on average, 4.6 different alleles per microsatellite. The 15 PCR-amplified microsatellites were further localized on chromosome arms using cytogenetic stocks of Chinese Spring. Finally, the primers for the 15 wheat microsatellites were used for PCR amplification with rye (Secale cereale) and barley accessions (Hordeum vulgare, H. spontaneum). Amplified fragments were observed for ten primer pairs with barley DNA and for nine primer pairs with rye DNA as template. A microsatellite was found by dot blot analysis in the PCR products of barley and rye DNA for only one primer pair. 相似文献
8.
部分耐盐小麦品种(系)SSR位点遗传多样性研究 总被引:8,自引:3,他引:5
选择有多态性的32对SSR引物对80个小麦耐盐品种(系)进行遗传差异研究,共检测出155个等位变异,平均每个位点上有4.75个等位变异;供试80份耐盐小麦品种(系)来源广泛,遗传基础丰富,表现出较高的遗传多样性,遗传相似系数范围在0.26~0.81;聚类分析结果显示,冬性小麦品种(系)聚为一大类;春性小麦品种(系)也聚为一大类;一些系谱相同或相近的品种(系)遗传相似系数较大;A、B、D基因组中SSR位点平均等位变异差异不大,以B基因组较高. 相似文献
9.
Jéssica Rosset Ferreira Jorge Fernando Pereira Caroline Turchetto Euclydes Minella Luciano Consoli Carla Andréa Delatorre 《Genetics and molecular biology》2016,39(1):86-96
Barley is a major cereal grown widely and used in several food products, beverage production and animal fodder. Genetic diversity is a key component in breeding programs. We have analyzed the genetic diversity of barley accessions using microsatellite markers. The accessions were composed of wild and domesticated barley representing genotypes from six countries and three breeding programs in Brazil. A total of 280 alleles were detected, 36 unique to Brazilian barley. The marker Bmag120 showed the greatest polymorphism information content (PIC), with the highest mean value found on chromosome three, and the lowest on chromosomes four and six. The wild accessions presented the highest diversity followed by the foreign genotypes. Genetic analysis was performed using Principal Coordinates Analysis, UPGMA clustering, and Bayesian clustering analysis implemented in Structure. All results obtained by the different methods were similar. Loss of genetic diversity has occurred in Brazilian genotypes. The number of alleles detected in genotypes released in 1980s was higher, whereas most of the cultivars released thereafter showed lower PIC and clustered in separate subgroups from the older cultivars. The use of a more diverse panel of genotypes should be considered in order to exploit novel alleles in Brazilian barley breeding programs. 相似文献
10.
Carina Mendes Loiola Alinne Oliveira Nunes Azevedo Leandro E. C. Diniz Wilson Menezes Arag?o Carlos Diego de O. Azevedo Pedro Henrique A. D. Santos Helaine Christine C. Ramos Messias Gonzaga Pereira Semíramis R. Ramalho Ramos 《PloS one》2016,11(3)
The diversity and genetic relationships among two accessions of tall coconut palms collected in Brazil and seven accessions introduced from different geographic regions of the world were analyzed using 25 microsatellite primers, 19 of which were polymorphic and detected between 4 and 10 alleles per locus, with an average of 6.57. The observed and expected heterozygosity ranged from 0.25 and 0.40 in the Rennell Islands Tall (RIT) accession to 0.54 and 0.62 in the Polynesian Tall (PYT) accession. The analysis of genetic structure resulted in the formation of five distinct groups. The first group was formed by the accessions Brazilian Tall—Praia do Forte (BRTPF), Brazilian Tall—Merepe (BRTMe) and West African Tall (WAT); the second group consisted of Malaysian Tall (MLT); the third group of RIT; the fourth group of Vanuatu Tall (VTT); and the fifth group of Rotuman Tall (RTMT), Tonga Tall (TONT) and PYT. The dendrogram based on the nearest-neighbor method detected the formation of two main groups and five subgroups, indicating that the genetic relationships of the accessions are based on their geographic regions of origin. The analyses revealed genetic relationships between the accessions collected in Brazil and the accession from Africa, and among palms from South East Asia and the South Pacific, confirming the common origin of these accessions. The information obtained in this study can guide decisions on germplasm conservation activities and the efficient selection of genetically divergent parents for use in coconut breeding programs in Brazil, which are attempting to select for disease resistance, mainly to lethal yellowing, among other characteristics. 相似文献
11.
Assessment of genetic diversity within and among germplasm accessions in cultivated sorghum using microsatellite markers 总被引:6,自引:0,他引:6
Y. Djè M. Heuertz C. Lefèbvre X. Vekemans 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(6):918-925
Microsatellite markers are increasingly being used in crop plants to discriminate among genotypes and as tools in marker-assisted
selection. Here we evaluated the use of microsatellite markers to quantify the genetic diversity within as well as among accessions
sampled from the world germplasm collection of sorghum. Considerable variation was found at the five microsatellite loci analysed,
with an average number of alleles per locus equal to 2.4 within accessions and 19.2 in the overall sample of 25 accessions.
The collection of sorghum appeared highly structured genetically with about 70% of the total genetic diversity occurring among
accessions. However, differentiation among morphologically defined races of sorghum, or among geographic origins, accounted
for less than 15% of the total genetic diversity. Our results are in global agreement with those obtained previously with
allozyme markers. We were also able to show that microsatellite data are useful in identifying individual accessions with
a high relative contribution to the overall allelic diversity of the collection.
Received: 10 August 1999 / Accepted: 27 August 1999 相似文献
12.
Sethy NK Shokeen B Edwards KJ Bhatia S 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(8):1416-1428
Paucity of polymorphic molecular markers in chickpea (Cicer arietinum L.) has been a major limitation in the improvement of this important legume. Hence, in an attempt to develop sequence-tagged microsatellite sites (STMS) markers from chickpea, a microsatellite enriched library from the C. arietinum cv. Pusa362 nuclear genome was constructed for the identification of (CA/GT)
n
and (CT/GA)
n
microsatellite motifs. A total of 92 new microsatellites were identified, of which 74 functional STMS primer pairs were developed. These markers were validated using 9 chickpea and one C. reticulatum accession. Of the STMS markers developed, 25 polymorphic markers were used to analyze the intraspecific genetic diversity within 36 geographically diverse chickpea accessions. The 25 primer pairs amplified single loci producing a minimum of 2 and maximum of 11 alleles. A total of 159 alleles were detected with an average of 6.4 alleles per locus. The observed and expected heterozygosity values averaged 0.32 (0.08–0.91) and 0.74 (0.23–0.89) respectively. The UPGMA based dendrogram was able to distinguish all the accessions except two accessions from Afghanistan establishing that microsatellites could successfully detect intraspecific genetic diversity in chickpea. Further, cloning and sequencing of size variant alleles at two microsatellite loci revealed that the variable numbers of AG repeats in different alleles were the major source of polymorphism. Point mutations were found to occur both within and immediately upstream of the long tracts of perfect repeats, thereby bringing about a conversion of perfect motifs into imperfect or compound motifs. Such events possibly occurred in order to limit the expansion of microsatellites and also lead to the birth of new microsatellites. The microsatellite markers developed in this study will be useful for genetic diversity analysis, linkage map construction as well as for depicting intraspecific microsatellite evolution. 相似文献
13.
The use of microsatellite markers for detection of genetic diversity in barley populations 总被引:41,自引:0,他引:41
D. Struss J. Plieske 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(1-2):308-315
A barley lambda-phage library was screened with (GA)n and (GT)n probes for developing microsatellite markers. The number of repeats ranged from 2 to 58 for GA and from 2 to 24 for GT. Fifteen
selected microsatellite markers were highly polymorphic for barley. These microsatellite markers were used to estimate the
genetic diversity among 163 barley genotypes chosen from the collection of the IPK Genebank, Germany. A total of 130 alleles
were detected by 15 barley microsatellite markers. The number of alleles per microsatellite marker varied from 5 to 15. On
average 8.6 alleles per locus were observed. Except for GMS004 all other barley microsatellite markers showed on average a
high value of gene diversity ranging from 0.64 to 0.88. The mean value of gene diversity in the wild forms and landraces was
0.74, and even among the cultivars the gene diversity ranged from 0.30 to 0.86 with a mean of 0.72. No significant differences
in polymorphism were detected by the GA and GT microsatellite markers. The estimated genetic distances revealed by the microsatellite
markers were, on average , 0.75 for the wild forms, 0.72 for landraces and 0.70 among cultivars. The microsatellite markers
were able to distinguish between different barley genotypes. The high degree of polymorphisms of microsatellite markers allows
a rapid and efficient identification of barley genotypes.
Received: 26 November 1997 / Accepted: 19 January 1998 相似文献
14.
应用微卫星标记研究西藏野生大麦的遗传多样性 总被引:9,自引:0,他引:9
以西藏不同地区的106份野生大麦为材料,其中包括50份野生二棱大麦(HS),27份野生瓶形大麦(HL)和29份野生六棱大麦(HA),用Liu等(1996)发表的SSR连锁图的每个连锁群的两个臂的不同位置上选取3~5个共30个SSR标记,研究了西藏3类野生大麦的遗传多样性。结果表明,这3类野生大麦在遗传组成及等位变异频率分布上存在着明显的遗传分化。在总样本中,共检测到229个等位变异,平均每个SSR位点检测到7.6个等位变异,其中70个为这3类野生大麦间共同的等位变异,等位变异数在这3类野生大麦间有明显的差异,亚种问的遗传多样性明显高于亚种内的遗传多样性。其遗传多样性大小顺序为HS〉HL〉HA。聚类分析表明,野生二棱大麦、野生六棱大麦分别聚在不同的两类,而野生瓶形大麦中各有约50%的材料分别聚在这两类。根据本研究及前人研究结果,我们认为中国栽培大麦是从野生二棱大麦经野生瓶形大麦向野生六棱大麦进化的。该结果支持了栽培大麦起源的“野生二棱大麦单系起源论”的观点。 相似文献
15.
Evaluation of the genetic diversity in conventional and modern rapeseed cultivars is essential for conservation, management
and utilization of these genetic resources for high yielding hybrid production. The objective of this research was to evaluate
a collection of 86 oilseed rape cultivars with 188 simple sequence repeat (SSR) markers to assess the genetic variability,
heterotic group identity and relationships within and between the groups identified among the genotypes. A total of 631 alleles
at 188 SSR markers were detected including 53 and 84 unique and private alleles respectively, which indicated great richness
and uniqueness of genetic variation in these selected cultivars. The mean number of alleles per locus was 3.3 and the average
polymorphic information content was 0.35 for all microsatellite loci. Unweighted Pair Group Method with Arithmetic Mean clustering
and principal component analysis consistently divided all the cultivars into four distinct groups (I, II, III and IV) which
largely coincided with their geographical distributions. The Chinese origin cultivars are predominantly assembled in Group
II and showed wide genetic base because of its high allelic abundance at SSR loci while most of the exotic cultivars grouped
into Group I and were highly distinct owing to the abundant private and unique alleles. The highest genetic distance was found
between Group I and IV, which mainly comprised of exotic and newly synthesized yellow seeded (1728-1 and G1087) breeding lines,
respectively. Our study provides important insights into further utilization of exotic Brassica napus accessions in Chinese rapeseed breeding and vice versa. 相似文献
16.
Amani Ben Naceur Ramzi Chaabane Mouldi El-Faleh Chedly Abdelly Dalila Ramla Ahmed Nada Mahmoud Sakr M’barek Ben Naceur 《Journal of Genetic Engineering and Biotechnology》2012,10(1):13-21
It was demonstrated that some North Africa barley accessions have diverse tolerance sources for abiotic stresses and a good nutritional quality, but the studies done were incomplete since they were realized separately in each country apart.To implement a more complete analysis, 31 barley accessions originated from North Africa (Algeria, Tunisia and Egypt) were analyzed using 11 SSR markers selected from the seven barley linkage groups for studying the genetic diversity among these chosen barley accessions.Over the 11 SSR markers, a total of 478 reproducible bands were scored with an average of 2.13 alleles/primer and the average polymorphism information content of 0.5.Genetic distance analysis of the 31 accessions showed a large genetic diversity and high number of different groups. The most accessions are clustered according to their eco-geographical origin, according to their pedigree and agronomic characters or according to the caryopsis character (hulled or naked caryopsis). This high number of obtained groups is an invaluable aid in crop improvement strategies and confirms the opinion suggesting that North Africa could be a secondary center of origin of barley. The various growing conditions and the multiple uses of barley in each country may be the cause of the large variability of the barley germplasm in each region. 相似文献
17.
Roa AC Chavarriaga-Aguirre P Duque MC Maya MM Bonierbale MW Iglesias C Tohme J 《American journal of botany》2000,87(11):1647-1655
Microsatellite amplification was performed on cassava (Manihot esculenta) and six other different species (all wild) of the Manihot genus. We used ten pairs of microsatellite primers previously developed from cassava, detecting 124 alleles in a sample of 121 accessions of the seven species. The number of alleles per locus ranged from four to 21 alleles, and allelic diversity was greater in the wild species than in cassava. Seventy-nine alleles, including unique ones, were detected in the wild species but were not found in the crop. The lower level of heterozygosity in some wild species probably resulted from a combination of fine-scale differentiation within the species and the presence of null alleles. Overall, microsatellite primers worked across the genus, but, with increasing genetic distance, success in amplifying loci tended to decrease. No accession of M. aesculifolia, M. carthaginensis, and M. brachyloba presented a banding pattern at locus Ga-140; neither did one appear for M. aesculifolia at locus Ga-13. Previous work with amplified fragment length polymorphism (AFLP) markers and this microsatellite analysis show that these three wild taxa are the most distant relatives of the crop, whereas the wild forms M. esculenta subsp. flabellifolia and M. esculenta subsp. peruviana appear to be the closest. 相似文献
18.
Ives Bruno M. Efombagn Juan C. Motamayor Olivier Sounigo Albertus B. Eskes Salomon Nyassé Christian Cilas Ray Schnell Maria J. Manzanares-Dauleux Maria Kolesnikova-Allen 《Tree Genetics & Genomes》2008,4(4):821-831
The genetic diversity of 400 accessions collected in cacao farms, 95 GenBank, and 31 reference accessions was analyzed using
the 12 microsatellite markers. The GenBank and reference accessions were subdivided into 12 accession groups (AG) that belong
to the traditional cacao genetic groups (GG) Lower Amazon Forastero (LA), Upper Amazon Forastero (UA), Trinitario, and Criollo
(Cr). The 12-microsatellite loci revealed a total of 125 alleles, 113 of which were present in the farm accession group (FA).
The within and between group variation for all AGs accounted respectively for 81% and 19% of the total molecular variation.
The average F
is for the FA was 0.15 suggesting a moderate level of inbreeding. Significant differences for the level of gene diversity were
found between the farm (0.50), GenBank (0.42 to 0.62), and reference (0.10 to 0.60) AGs. Genetic differentiation among AGs
was variable with F
st values varying between 0.14 and 0.57 for the different AGs. Analysis using a Bayesian model-based method showed the existence
of a high level of admixture for the farm accessions group. The LA genes were most represented in the FA (54%), followed by
UA (33%) and Cr (7%). The genes of LA were also the most represented in the GenBank (48%), followed by UA (24%) and Cr (14%).
Only 14% and 6% of the genes of the GenBank and farm accessions, respectively, could not be attributed to any of the reference
GGs. The results suggest the predominating presence of LA genes in the Cameroon farm accessions and a high level of admixture,
with apparent presence of genes of more than three GGs in most accessions. The traditional Trinitario types appear to have
almost disappeared from farmers fields. The admixture must be the result of hybridization and recombination of these genes
from the different GGs in seed gardens and in farmers’ fields. The use of selected farm accessions will depend on the GG that
it belongs to and also on their level of heterozygosity. Further implications of the results for breeding and for introduction
of new germplasm into the Cameroon GenBank are discussed. 相似文献
19.
Qiong Zhang Jing Li Yongbo Zhao Schuyler S. Korban Yuepeng Han 《Plant Molecular Biology Reporter》2012,30(3):539-546
China, one of the primary centers of genetic diversity for the genus Malus, is very rich in wild apple germplasm. In this study, genetic diversity in 29 Malus accessions, including 12 accessions from 7 Chinese Malus species, 4 Chinese landraces, and 13 introduced apple cultivars, was assessed using a set of 19 single-locus simple sequence repeat (SSR) markers distributed across all 17 linkage groups of the apple genome. The number of alleles detected at each locus ranged from 2 to 11, with an average of 5.3 per SSR marker. In some accessions, 16 unique alleles were identified. Ten out of these 16 unique alleles (62.5%) were detected exclusively in wild species, indicating that these Chinese wild apple species have considerable genetic diversity and can be used in breeding programs to increase the genetic diversity of apple cultivars. Using 19 SSRs, an unweighted pair-group method with arithmetic average cluster analysis was conducted, and the resulting dendrogram revealed that all cultivars, except for E??peMeBckoe, were clustered together in the same group. The Russian cultivar E??peMeBckoe was closely related to the Chinese crabapple Baihaitang (M. prunifolia), with a high similarity coefficient value of 0.94. Of the two M. sieversii accessions used, one accession showed a close relationship to apple cultivars, while the other accession was closely related to wild apple species, suggesting the presence of a wider genetic diversity in Chinese M. sieversii species. The influence of SSR marker selection on genetic diversity analysis in this Malus collection was also discussed. 相似文献
20.
Genetic diversity in date palm germplasm from Sudan representing 37 female and 23 male accessions was investigated using 16 loci of microsatellite (SSR) primers. Eight female accessions from Morocco were included as reference material. The tested SSR markers showed a high level of polymorphism. A total of 343 alleles were detected at the 16 loci. The number of alleles per marker ranged from 14 to 44 with an average of 21.4 per locus. A high level of expected heterozygosity was observed among Sudan cultivars (0.841), Morocco cultivars (0.820) and male accessions (0.799). The results indicate that the genetic groups of the Sudan cultivars and/or males do not follow a clear geographic pattern. However, the morocco group showed significant differentiation in relation to the Sudan groups, as measured by F (ST) values and genetic distances. The effect of the methods of pollination and cultivar selection on the genetic structure was clearly detected by the weak clustering association that was observed for the majority of accessions originating from Sudan and Morocco as well. This suggests the need for further investigation on the genetic diversity of Sudanese date palm germplasm. A deeper insight will be revealed by a detailed analysis of populations originating from different geographic locations. 相似文献