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1.
Fifteen amplified fragment length polymorphism (AFLP) EcoRI/MseI‐based primer combinations with five selective bases (Eco RI‐ANN, MseI‐CN) were used to estimate genetic diversity among 45 line varieties of cultivated cornsalad and 19 genebank accessions classified into nine different species related to cornsalad. Polymorphic fragments were scored for calculation of Jaccard's coefficient of genetic similarity (GS). The average GS estimate in elite germplasm (GS = 0.90) was substantially higher than in exotic germplasm (GS = 0.47). UPGMA‐cluster analysis revealed genetic relationships among recently bred varieties, old varieties and genebank accessions. Analysis of molecular variance indicated almost threefold variability within sets compared with between sets due to a high level of polymorphism among wild species. Sources for increasing genetic diversity in elite germplasm of cornsalad were suggested and a duplicate among the genebank accessions was detected. AFLPs could be considered a powerful tool for genetic diversity estimation in cornsalad germplasm and are recommended for systematic fingerprinting of remaining cornsalad species. 相似文献
2.
Water yam (Dioscorea alata L.) is the most widely cultivated food yams. Despite its importance, its production is limited by anthracnose disease caused
by Colletotrichum gloeosporioides (Penz.). The use of resistant yam varieties is the most reliable approach of management of this disease. The speed and precision
of breeding can be improved by the development of genetic linkage maps which would provide the basis for locating and hence
manipulating quantitative traits such as anthracnose resistance in breeding programmes. An F1 diploid population was developed
by crossing ‘Boutou’ a female clone (with field resistance to anthracnose) with ‘Pyramide’ (susceptible). A linkage map was
generated with 523 polymorphic markers from 26 AFLP primer combinations. The resulting map covered a total length of 1538 cM
and included 20 linkage groups. It is the most saturated of all genetic linkage maps of yam to date. QTL analysis of anthracnose
resistance was performed based on response to two isolates of C. gloeosporioides. Resistance to anthracnose appeared to be inherited quantitatively. Using a LOD significance threshold of 2.6 we identified
a total of nine QTLs for anthracnose resistance. The phenotypic variance explained by each QTL ranged from 7.0 to 32.9% whereas
the total amount of phenotypic variation for anthracnose resistance explained by all significant QTLs varied from 26.4 to
73.7% depending on the isolate and the variable considered. These QTLs displayed isolate-specific resistance as well as broad
spectrum resistance. The availability of molecular markers linked to the QTLs of anthracnose resistance will facilitate marker-assisted
selection in breeding programmes. 相似文献
3.
Genetic diversity of 18 Brassica nigra accessions was estimated using amplified fragment length polymorphism (AFLP) marker technology. Two B. rapa and two B. juncea accessions were selected as outliers in the study. Eight AFLP primer combinations generated a total of 426 bands, of which 79% were polymorphic. The UPGMA method was employed to construct a dendrogram based on the Jaccard's similarity coefficient. The accessions of B. rapa separated from those of B. nigra at a genetic similarity coefficient of 0.27 while those of B. juncea did so at 0.5. The genetic similarity coefficients within the B. nigra accessions ranged from 0.58 to 0.86. Based on these coefficients it was concluded that the B. nigra accessions show high levels of genetic variation. These results have significant implications in the crop improvement programmes for the agronomically important crop B. juncea, an amphidiploid of B. nigra and B. rapa. Two incorrectly labelled B. nigra accessions were also identified. These accessions were found to cluster with those of B. juncea accessions. This result demonstrates the great value of AFLP markers in the management of genebanks. 相似文献
4.
Zingiber zerumbet (L) Smith, a wild clonal species related to the cultivated ginger (Zingiber officinale Roscoe), is a potential resistance donor for soft rot disease in ginger caused by Pythium aphanidermatum (Edson) Fitzp. In this study we evaluated the genetic diversity and P. aphanidermatum resistance of 74 Z. zerumbet accessions belonging to 15 populations from eight districts in Kerala state, India. The disease index (DI) of the accessions
varied from 0% to 72.24% and the accessions could be separated into six frequency classes according to their DI values. More
than 65% of the accessions had a DI < 20%. Eight accessions were found to be immune to the infection. The relative frequency
of resistant accessions was higher in the central and northern regions of Kerala. Amplified fragment length polymorphism (AFLP)
analysis of Z. zerumbet accessions using five primer combinations yielded 215 bands in total, of which 175 (81.4%) were polymorphic. Nei’s genetic
diversity (h) of 0.2738 and Shannon information index (I) of 0.4012 revealed a high genetic diversity in Z. zerumbet unexpected for a clonal species. In the UPGMA dendrogram, accessions were clustered mostly according to their geographical
origin and no clear correspondence was observed between the clustering pattern of accessions and their responses to Pythium aphanidermatum. The study revealed high genetic diversity and variability for pathogen resistance among Z. zerumbet accessions and confirmed the value of Z. zerumbet as a potential donor for soft rot resistance for the genetic improvement of ginger. 相似文献
5.
Summary Random amplified polymorphic DNA (RAPD) analysis was carried out to evaluate polymorphism and genetic similarity between 39 Mediterranean mandarin genotypes. One hundred eleven amplification products were identified using 21 random primers. An average of 2.2 RAPD markers was obtained for each primer, corresponding to 42% of the amplification products. Genotype-specific RAPD markers were also found, mainly in known hybrids. UPGMA cluster analysis revealed the low level of genetic variation between accessions of Mediterranean mandarins, whereas their hybrids with other Citrus species showed greater genetic dissimilarity. Twenty accessions yielded very similar patterns, suggesting either that they could be a single clone, or that the technique was not able to detect genomic variation. However, for the other specimens genetic polymorphism can easily be detected by RAPD, although the genetic variation between accessions was quite low. The large number of hybrids and the low polymorphism between accessions support the hypothesis that Mediterranean mandarins are all true hybrid of Common mandarins (Citrus reticulata Blanco). 相似文献
6.
Melissa de Oliveira Santos-Garcia Rosângela Maria Simeão Resende Lucimara Chiari Maria Imaculada Zucchi Anete Pereira de Souza 《Euphytica》2011,178(2):185-193
Stylosanthes capitata and S. guianensis are important forage legumes for tropical areas. The only available estimates of S. capitata and S. guianensis outcrossing rates were based on morphological markers, and the genus is considered as being mainly self-pollinated. Here
we describe an estimation of the outcrossing rate in S. capitata and S. guianensis using microsatellite markers. The outcrossing rates were estimated in S. capitata and S. guianensis open-pollinated populations of 20 progenies consisting of ten individuals each. The multi locus outcrossing rate for S. capitata was estimated using 10 polymorphic loci, whereas five microsatellites were used for S. guianensis. The multi locus outcrossing rates for S. capitata and S. guianensis were 31 and 26%, respectively, suggesting a mixed mating system with predominance of autogamy. Comparison of single locus
and multi locus estimates of outcrossing rates indicated that little inbreeding other than selfing occurred. The estimated
Wright’s fixation index of the parental generation was lower than expected based on the multi locus outcrossing rate, possibly
resulting from the use of some heterozygous breeding genotypes for the study. The data on the outcrossing rate described here
are potentially useful for breeding programs and for maintenance of germplasm collections of these Stylosanthes species. 相似文献
7.
Genetic diversity of eight selected Argentinean garlic clones (Allium sativum L.) were investigated at the DNA level with the amplified fragment length polymorphism DNA (AFLP) procedure. A total of 405
unambiguous bands were identified by six primer combinations of EcoR I +3 and Mse I +3, of those, 398 showed a clear polymorphism, representing 98% of the total bands. A presence/absence matrix was constructed
with the polymorphic bands, and a dendrogram was obtained from it with the UPGMA method. The accessions showed different levels
of similarity ranging between 0.24 and 0.97, using the coefficient of Jaccard. The dendrogram showed six arbitrary groups.
Accessions typically considered as different clones show similarities between 0.97 and 0.495. The garlic clones were clustered
according to the physiological group and bulb color. We could detect an association between AFLP and the geographical origin
of the clones. The potential use of AFLP could allow not only the differentiation among species, but also between botanical
varieties and well-defined ecotype groups. This is the first report of the use of AFLP to characterize Argentinean garlic
clones.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
9.
The objectives of this study were to optimize RAPD and AFLP techniques in B. catharticus, and to determine the genetic variability of populations and commercial prairie grass cultivars with the aforementioned molecular
markers. Two populations with contrasting morphological characteristics were evaluated from individual and bulked DNA samples
using RAPD markers. Both analyses showed a similar information about inter population variability. Each accession was sampled
by a single leaf bulk of 10 plants. Accession similarities were established with 276 RAPD and 714 AFLP bands using Jaccard
similarity coefficient. The dendrogram of the accessions using RAPD markers showed that they shared high similarity values
(>94%). A similar result was obtained with AFLP markers (similarity values >98%), revealing a narrow genetic basis in the
analyzed accessions. Consequently, molecular characterization of germplasm should be considered in addition to morphological
criteria, to choose the parental genotypes for breeding programs of this forage crop. The AFLP technique was more efficient
to detect DNA polymorphism in our experiments and unique fingerprints were detected for all the accessions. RAPD is a simple
and non expensive technique, suitable to estimate genetic similarity.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
10.
11.
Cultivation of sunflower (Helianthus annuus L.) is strongly affected by Sclerotinia sclerotiorum. To identify new sources of genetic diversity for sunflower breeding 25 sunflower inbred lines were analysed using eight Amplified Fragment Length Polymorphism (AFLP) primer combinations and their genetic similarities (GS) were estimated. Data were used to develop a Unweighted Pair Group Method using Arithmetic Averages (UPGMA) dendrogram. GS values of 0.58‐0.98 were observed but with no separate groupings dependant on oil quality. The inbred lines were screened for their reaction to inoculation with Sclerotinia sclerotiorum (Lib.) de Bary. Sunflower heads were artificially inoculated with S. sclerotiorum in three environments. Head infection was monitored after 1 week (lesion length) and 2 weeks (head rot). The F5 generation of a cross between a resistant (SWS‐B‐04) and a susceptible inbred line (SWS‐B‐01) was also tested for sclerotinia reaction across three environments. Significant differences in sclerotinia resistance, moderate heritabilities and a high correlation between the two assessments were observed. Inbred lines with a high level of resistance could be identified. These lines can be used for further breeding to improve sunflower sclerotinia resistance and to develop superior new hybrids. 相似文献
12.
Genetic diversity and relationships among pea cultivars revealed by RAPDs and AFLPs 总被引：10，自引：0，他引：10
In order to obtain an overview of the genetic diversity present within the set of pea cultivars released in Germany, 21 cultivars were analysed at the DNA level by random amplified polymorphic DNAs (RAPDs) and amplified fragment length polymorphisms (AFLPs), as well as for agronomic traits. Yield of grain cultivars ranged from 2.95 to 3.87 t/ha. Based on the screening of 60 RAPD primers and 32 Eco RI + 3/Mse I+3 AFLP primer combinations, 20 RAPD primers and 11 Eco RI + 3/MseI+ 3 primer combinations generating polymorphic and distinct fragments were chosen for estimation of genetic diversity. Twenty RAPD primers amplified a total of 314 scorable bands ranging from about 262 bp to 1996 bp. Of these, 175 fragments (55.7%) were polymorphic. Based on these data, genetic similarity (GS) was estimated between 0.80 (‘Lisa’ vs.‘Grapis’) and 0.94 (‘Bohatyr’ vs. ‘Sponsor’; mean GS = 0.88). Eleven AFLP primer combinations led to the amplification of 949 scorable fragments ranging from 43 to 805 bp and of these, 462 (48.7%) were polymorphic. Genetic similarity based on AFLPs was calculated between 0.85 (‘Lisa’ vs.‘Laser’) and 0.94 (‘Bohatyr’ vs. ‘Sponsor’, mean GS = 0.90). Correlation of genetic similarity estimated on RAPDs and AFLPs was estimated at r = 0.79** using Spearman's rank correlation coefficient and at r = 0.84 by the Mantel test, respectively. UPGMA cluster analysis carried out on these data separately for RAPDs and AFLPs and on the combined data reflected, to some extent, pedigree relationships and cophenetic correlations (r = 0.89 for RAPDs, r = 0.88 for AFLPs, and r = 0.93 RAPDs + AFLPs) indicate a good fit of respective clusters to genetic similarity data. The correlation of cluster analyses to pedigree information and the impact on parental genotype selection is discussed. 相似文献
13.
Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), is an important insect pest which causes severe economic losses in wheat (Triticum spp.). Among the various U.S. RWA biotypes, biotype 1 (RWA1) and biotype 2 (RWA2) are the most prevalent and most virulent
on cultivated genotypes. Although many sources of resistance to these biotypes are available among landraces, their relatedness
should be characterized to permit their more efficient use in breeding programs. In this study, 38 hexaploid accessions resistant
to biotype 1 and/or biotype 2 were evaluated for genetic diversity based on amplified fragment length polymorphisms (AFLP).
Fifteen AFLP selective primer combinations were used to genotype these accessions, resulting in 893 amplicons. Of these, 274
(30.6%) informative polymorphic bands were used for genetic diversity analysis. Genetic similarity coefficients ranged from
0.47 to 0.87 among the resistant accessions, indicating high genetic diversity among them. Cluster analysis grouped the 38
accessions into two major clusters, I and II, including resistant lines for RWA1 and RWA2. The study indicated that accessions
in the National Small Grains Collection conferring RWA1 or RWA2 resistance comprise a diversified population which should
support introgression efforts and provide genetic diversity for future breeding for RWA resistance. 相似文献
14.
The amplified fragment length polymorphism (AFLP) procedure was applied to a diverse panel of wheat (Triticum aestivum L. em. Thell.) accessions and sixty-nine of the recombinant inbred lines (RILs) from the widely used genetic mapping population
derived from the cross of Opata 85 and W7984. Most (76.8%) bands were monomorphic among T. aestivum accessions. The majority of bands monomorphic in T. aestivum also were present in the synthetic wheat parent (W7984). Ten primer pairs generated 153 polymorphic AFLP bands, 140 of which
could be assigned to a chromosome location and were relatively evenly distributed on the genetic linkage map. AFLP loci in
T. aestivum were distributed throughout the genome; they generally have only one detectable sequence variant; and they exhibit monogenic
dominant mendelian inheritance. Frequencies of polymorphic bands in the germplasm sampled are in the range that enables informative
cluster analyses as well as map-based diversity and association analysis studies. AFLP bands mapped to individual loci in
the Opata 85/W7984 RIL population will frequently be polymorphic in other crosses or germplasm, irrespective of whether the
band arises from the T. aestivum parent or the synthetic wheat parent.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
15.
Tef is an important cereal crop in Ethiopia. This study was conducted to investigate (1) genetic diversity within and among three Eragrostis species (E. tef, E. pilosa and E. curvula), and (2) the relationship between E. tef, E. pilosa and E. curvula. A total of 529 AFLP markers were obtained, out of which 58% (368) were polymorphic, using 10 primer, combinations. The three species were separated distinctly using amplified fragment length polymorphism (AFLP), However, diversity revealed at the morphological trait level was not commensurate with that observed for AFLP. This was due to the small number of morphological traits available and their interaction with the environment. Within tef, ‘Rubicunda’ and DZ‐01‐1093 were found to be distantly related to the rest of the tef accessions. The diversity within species was such that E. pilosa was the most diverse followed by E. curvula and E. tef. Moreover, E. pilosa was more closely related to E. tef than E. curvula. Therefore, further study is needed of E. pilosa accessions and of ‘Rubicunda’ and DZ‐01‐1093 in a crossing programme to generate a population for selection and/or genetic mapping. A total of 19 cultivars or accessions had one or more unique fragments using one or more AFLP primers, indicating the potential of the technology in fingerprinting tef in a breeding or seed multiplication programme. 相似文献
16.
P. Ramasamy M. A. Menz P. J. Mehta S. Katilé L. A. Gutierrez-Rojas R. R. Klein P. E. Klein L. K. Prom J. A. Schlueter W. L. Rooney C. W. Magill 《Euphytica》2009,165(3):597-606
Anthracnose, caused by the fungus Colletotrichum sublineolum is one of the most destructive diseases of sorghum and has been reported in most areas where the crop is grown. Several control
strategies have been developed but host plant resistance has been regarded as the most effective strategy for disease control.
Here, we describe the search for molecular markers that co-segregate with Cg1, a dominant gene for resistance originally identified in cultivar SC748-5. To identify molecular markers linked with the
Cg1 locus, F2:3 plants derived from a cross to susceptible cultivar BTx623 were analyzed with 98 AFLP primer combinations. BTx623 was chosen
as the susceptible parent because it is also one on the parents used in creating RFLP and AFLP maps and BAC libraries for
sorghum. Four AFLP markers that cosegregate with disease resistance were identified, of which Xtxa6227 mapped within 1.8 cM of the anthracnose resistance locus and all four AFLP markers have been previously mapped to the end
of sorghum linkage group LG-05. Sequence scanning of BAC clones spanning this chromosome led to the discovery that Xtxp549, a polymorphic simple sequence repeat (SSR) marker, mapped within 3.6 cM of the anthracnose resistance locus. To examine
the efficacy of Xtxa6227 and Xtxp549 for marker-assisted selection, 13 breeding lines derived from crosses with sorghum line SC748-5 were genotyped. In 12 of
the 13 lines the Xtxa6227 and Xtxp549 polymorphism associated with the Cg1 locus was still present, suggesting that Xtxp549 and Xtxa6227 could be useful for marker-assisted selection and for pyramiding of Cg1 with other genes conferring resistance to C. sublineolum in sorghum. 相似文献
17.
18.
试验取30个枣树优良主栽品种进行AFLP分子标记,并进行遗传聚类分析,以期获得不同枣树品种之间的亲缘关系特征。从64对引物组合中筛选出9对重复性和稳定性好的引物组合,总共扩增出399条清晰条带,即对枣品种基因组399个位点进行了检测,其中共有位点85个,多态性位点314个,多态性百分率78.70%,可鉴别出所有供试品种。UPGMA聚类表明,30个枣树品种的相似系数在0.4654-0.8231之间,平均相似系数为0.6223,在相似系数0.666处,可将供试的30个枣树品种分为6类,为枣树品种分类及亲缘关系分析提供了有力参考。 相似文献
19.
DNA amplification fingerprinting (DAF) techniques were used to evaluate genetic relationships among 24 randomly selected white lupin (Lupinus albus L.) accessions originating from four endemic regions. Parameters affecting DAF were optimized to obtain high resolution and reproducible banding patterns. DNA amplification was tolerant to a wide range of both template and primer concentrations but sensitive to Mg2+ concentration, and annealing temperature and time. Pure template DNA was found to be essential for obtaining reproducible banding patterns. Primer annealing occurred at multiple sites, permitting detection of polymorphism using only a single primer. Of 56 octamer primers tested, 22 yielded highly polymorphic DAF bands that could be used to distinguish closely related accessions. Genetic similarity coefficients were calculated and a dendrogram, using the unweighted pair group method with arithmetic average (UPGMA), was constructed. A high level of genome diversity was found among the accessions, but several from the Middle East and West Africa tended to cluster together. The results support the future use of DAF markers for the characterization and identification of white lupin germplasm. 相似文献
20.
Genetic relationships between Southern African Solanum retroflexum Dun. and other related species measured by morphological and DNA markers 总被引：1，自引：0，他引：1
In this study, the genetic relationship between 14 genotypes of black nightshade, most which were part of the Solanum nigrum complex, was investigated. Fifteen morphological characters were measured and used to compile a dendrogram. Amplified fragment
length polymorphism (AFLP) markers were also used to assess the level of polymorphism between the 14 Solanum genotypes. Three EcoR I/Mse I primer combinations with three selective nucleotides per primer were used for screening the respective genotypes. Multiple
polymorphisms could be detected to the extent that all the genotypes studied could be distinguished, using any single primer
combination, thus showing the usefulness of AFLP's for this purpose. Up to 43 polymorphic bands were detected with a single
primer combination among the 14 different genotypes. The three primer combinations generated a total of 359 bands, of which
222 (62%) were clearly polymorphic. This data was used to compile a dendrogram. Both the morphological and AFLP marker analysis
clearly separated the different genotypes into similar groups.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献