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1.
K. B. Singh B. Ocampo 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(3):418-423
Chickpea (Cicer arietinum L.) ranks third in the world, and first in the Mediterranean basin, for production among pulses. Despite its importance as
a crop and considerable research effort, traditional breeding methods have so far been unable to produce cultivars with a
large impact on chickpea production. Interspecific hybridization is known to improve yield in many crops. Therefore, an attempt
was made to increase the seed yield in chickpea through the introgression of genes from wild relatives at the International
Center for Agricultural Research in the Dry Areas (ICARDA), Syria, from 1987 to 1995. Four crosses, ILC 482 (C. arietinum)×ILWC 179 (C. echinospermum) and ILC 482×ILWC 124 (C. reticulatum) and their reciprocals, were made. Pedigree selection was used to advance the material. Heterosis was recorded visually in
F1s, and single plant measurements for seed yield were recorded in F2 populations. Promising and uniform progenies were bulked in the F5 generation. Out of 96 F6 lines, 22 were selected on the basis of seed yield and other agronomic characters, and evaluated in a replicated trial for
seed yield and 14 agronomical, morphological and quality characters. A high level of heterosis was observed in F1s. Several F2 plants produced two to three times more seed yield than the best plant from the cultigen. Nine F7 lines out-yielded the cultigen parent by up to 39%. Over 2 years, 12 lines had a higher yield than the cultigen parent. These
lines were not only high yielding but also free of any known undesirable traits from the wild species, such as spreading growth
habit, pod dehiscence, and non-uniform maturity. Quality traits, such as seed shape, type, colour, weight, and testa texture,
protein content, cooking time and an organoleptic test of a Middle East dish, Homos Bi-Tehineh, were also similar to the cultigen parent. Both C. echinospermum and C. reticulatum contributed towards the increased yield.
Received: 11 July 1996 / Accepted: 15 November 1996 相似文献
2.
A. Marhic S. Antoine-Michard J. Bordes M. Pollacsek A. Murigneux M. Beckert 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(4):520-525
Two cycles of androgenetic in vitro doubled haploid (DH) plant production and intermating were implemented in an experimental
synthetic population of maize. In vitro traits, including androgenetic embryo production, the regeneration potential and the
frequency of spontaneous chromosome doubling, were studied. The success of the regenerated plants to self pollinate was also
observed. Impressive genetic progress is reported for all the steps of the androgenetic process including seed set. Differential
genetic progress is recorded according to the trait measured. Using a set of Mendelian and molecular markers that mapped to
the different maize chromosomes, we were able to characterize the variation in the genetic variability in the population.
Progress in the in vitro response was not found to be associated with any noticeable decline in global genetic variability.
In addition, the QTL chromosomic regions tested, which were involved in androgenetic response, were not found to be subjected
to a strong variation during the breeding experiment. Some phenotypical and morphological traits were also evaluated, and
these showed that there was no depreciation effect in the agronomic value of the population. DH plant production and intermating
the regenerated plants may be considered for the introduction and use of androgenesis in material which responds poorly.
Received: 3 October 1997 / Accepted: 25 November 1997 相似文献
3.
The genetic diversity of annual wild soybeans grown in China 总被引:13,自引:0,他引:13
Y. S. Dong B. C. Zhuang L. M. Zhao H. Sun M. Y. He 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,103(1):98-103
Annual wild soybeans (Glycine soja), the ancestors of cultivated soybeans (G. max), are important sources of major genes for resistance to pests, diseases and environmental stresses. The study of their genetic
diversity is invaluable for efficient utilization, conservation and management of germplasm collections. In this paper, the
number of accessions, the variation of traits, the genetic diversity indexes (Shannon index) and the coefficient of variation
were employed to study the geographical distribution of accessions, genetic diversity of characters and genetic diversity
centers of annual wild soybean by statistical analysis of the database from the National Germplasm Evaluation Program of China.
Most annual wild soybeans are distributed in Northeast China, and the number of accessions decreases from the Northeast to
other directions in China. The genetic diversity indexes (Shannon index) were 0.49, 0.74, 0.02, 0.55, 1.45, 2.41, 1.27 and
1.89 for flower color, sootiness of seed coat, cotyledon color, pubescence color, hilum color, leaf shape, stem type and seed
color, respectively. Coefficients of variation were 7.1%, 28.7%, 76.43% and 18.2% for protein content, oil content, 100-seed
weight and days to maturity, respectively. Three genetic diversity centers, the Northeast, the Yellow River Valley and the
Southeast Coasts of China, are proposed based on the geographical distribution of the number of accessions, genetic diversity
and the multivariate variation coefficient. Based on these results and Vavilov’s theory of crop origination, two opposing
possible models for the formation of the three centers are proposed, either these centers are independent of each other and
the annual wild soybeans in these centers originated separately, or the Northeast center was the primary center for annual
wild soybeans in China, while the Yellow River Valley center was derived from this primary center and served as the origin
for the Southeast Coast center.
Received: 25 June 2000 / Accepted: 18 October 2000 相似文献
4.
Combining genetic gain and diversity by considering average coancestry in clonal selection of Norway spruce 总被引:3,自引:0,他引:3
Y. Q. Zheng D. Lindgren O. Rosvall J. Westin 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(8):1312-1319
Genetic relationship within a population can be measured by average coancestry. This can also be expressed as an effective
number which represents the relative genetic diversity of the population. The goal of breeding can be formulated to maximise
genetic value minus average coancestry times a constant (the “penalty constant”). An iterative search algorithm can then be
used to find the best selections for meeting this goal. Two such algorithms, one for a fixed number of selections and the
other for a variable optimum number, were applied to select a mixture of field-tested Norway spruce clones with known parents.
The results were compared with those from the conventional method of restricting parental contributions to the selected population
as a means to control diversity. Coancestry-adjusted selection always yielded more gain than restricted selection at a given
effective population size (except under circumstances where the methods were equivalent). Expressed another way, at any given
level of gain, coancestry-adjusted selection maintained a larger effective population size than did restricted selection.
The relative superiority of coancestry-adjusted selection declined when the effective population size approached the lowest
value, that at which no penalty or restriction was applied. The method was extended by the second search algorithm to optimise
the selected number of clones. The optimal number of clones can be rather large when diversity is heavily valued, but the
reduction in genetic gain becomes large.
Received: 7 April 1997 / Accepted: 9 June 1997 相似文献
5.
Phylogenetic analysis in the genus Cicer and cultivated chickpea using RAPD and ISSR markers 总被引:5,自引:0,他引:5
Iruela M Rubio J Cubero JI Gil J Millán T 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(4):643-651
Seventy five accessions belonging to 14 species of the genus Cicer were analysed with PCR-based molecular markers to determine their phylogenetic relationships. Eight of the species were annuals
and included the Section Monocicer which contains cultivated chickpea (Cicer arietinum L.). The remaining six species were perennials (five from Section Polycicer and one from Section Acanthocicer). More than
one accession per species was analysed in most of the wild species; within C. arietinum, 26 accessions including Kabuli and Desi types, were studied. RAPD analyses using 12 primers gave 234 polymorphic fragments. Variability
within species was detected. A dendrogram based on the Jaccard similarity index showed that the distribution pattern of variability
between species was related to both growth habit and geographical origin. An accession of Cicer reticulatum was closer to accessions of Cicer echinospermum than to the four remaining of C. reticulatum, suggesting the possibility of gene flow between species. Cluster analysis for cultivated chickpea differentiated Kabuli and
Desi types but we did not detect a clear relationship between groups and the geographical origin of the accessions.
Received: 5 April 2001 / Accepted: 13 July 2001 相似文献
6.
Levels of genetic diversity at different stages of the domestication cycle of interior spruce in British Columbia 总被引:3,自引:0,他引:3
M. U. Stoehr Y. A. El-Kassaby 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(1):83-90
Concerns over the reductionist nature of the domestication of forest-tree species focus on the possibility of potential genetic
erosion during this process. To address these concerns, genetic diversity assessments in a breeding zone the Province of British
Columbia “interior” spruce (Picea glauca×engelmanni) program was conducted using allozyme markers. Genetic-variation comparisons were made between natural and production (seed
orchard) populations as well as seed and seedling crops produced from the same breeding zone’s seed orchard. The natural population
sample consisted of a total of 360 trees representing three stands within each of three watersheds present in the Shuswap-Adams
low-elevation zone of interior British Columbia. Small amounts of genetic differentiation were observed among the nine natural
populations (4%) and this was attributable to extensive gene flow Consequently, the sum of these nine populations was considered as a baseline for the genetic variation present in the breeding
zone. The comparisons between the seed orchard and the breeding zone produced a similar percentage of polymorphic loci while the expected hetrozygosity (0.207 vs 0.210) and the average number of alleles per locus (2.7 vs 2.4) were slightly lower in the seed orchard. A total
of seven natural populations’ rare alleles were not present in the orchard population, while one allele was unique to the orchard. The %P increased to 70.6% in the seedlot, but dropped to the natural populations level (64.7%) in the plantation. The observed increase
in %P was a result of pollen contamination in the orchard. It is suspected that the reduction in the plantation was caused by an
unintentional selection in the nursery. Simulated roguing in the orchard did not drastically reduce even if up to 50% of the orchard’s clones were rogued. However, roguing was associated with a reduction in the average number
of alleles per locus (i.e., sampling effect).
Received: 2 January 1996 / Accepted: 24 May 1996 相似文献
7.
S. Kicherer G. Backes U. Walther A. Jahoor 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(6):881-888
The Hordeum vulgare accession ’HOR 1063’ was crossed with the barley cultivar Krona, and 220 doubled haploid lines were produced based on this
cross. A molecular map was constructed based on RFLP markers. Field trials were performed over 2 years and at two locations.
In field trials, resistance to leaf rust by means of artificial infection, heading date, plant height and Kernel weight were
assessed. For leaf rust resistance, 4 QTLs were localised, that explained 96.1% of the genetic variation. One QTL on chromosome
4H confirmed a position found in another genetic background and one mapped to the same position as Rph16 on chromosome 2H. All digenic effects decreased the effects of the respective QTLs. In addition to the denso-locus and the hex-v locus, other QTLs influencing heading date, plant length and kernel weight were found in this cross.
Received: 16 July 1999 / Accepted: 7 September 1999 相似文献
8.
Use of SAMPL for a study of DNA polymorphism,genetic diversity and possible gene tagging in bread wheat 总被引:5,自引:0,他引:5
Roy JK Balyan HS Prasad M Gupta PK 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(2-3):465-472
Selective Amplification of Microsatellite Polymorphic Loci (SAMPL) technology was used in bread wheat for the first time for a study of genetic diversity, genotype identification
and gene tagging. The diversity studies involved 55 wheat genotypes and two SAMPL primer pairs (SAMPL-6 and SAMPL-7, each
with a M-CAG primer), which together gave 43 polymorphic bands out of a total of 87 SAMPL bands. The average polymorphic information
content (PIC) of SAMPL primers was 0.221 and that of SAMPL markers was 0.264. The marker index of SAMPL markers was 9.61.
The genetic similarity (GS) coefficients for 1,485 pairs of genotypes ranged from 0.35 to 0.96 with an average of 0.65. A
dendrogram was prepared on the basis of a similarity matrix using the UPGMA algorithm, which corresponded well with the results
of principal component analysis (PCA). From a total of 55 genotypes, 54 could be distinguished using the SAMPL banding patterns
of both primers. For gene tagging, 568 bands from a total of 1,185 SAMPL bands detected polymorphism between each of the three
pairs of parents differing for grain protein content (GPC), pre-harvest sprouting tolerance (PHST) and grain weight (GW).
An association of six bands with GPC, of seven bands with PHST and four bands with GW was observed using bulked segregant
analysis (BSA).
Received: 5 April 2001 / Accepted: 17 May 2001 相似文献
9.
A genetic linkage map of durum wheat 总被引:14,自引:6,他引:14
A. Blanco M. P. Bellomo A. Cenci C. De Giovanni R. D’Ovidio E. Iacono B. Laddomada M. A. Pagnotta E. Porceddu A. Sciancalepore R. Simeone O. A. Tanzarella 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(5-6):721-728
A genetic linkage map of tetraploid wheat [Triticum turgidum (L.) Thell.] was constructed using segregation data from a population of 65 recombinant inbred lines (RILs) derived from
a cross between the durum wheat cultivar Messapia and accession MG4343 of T. turgidum (L.) Thell. ssp dicoccoides (Korn.) Thell. A total of 259 loci were analysed, including 244 restriction fragment length polymorphisms (RFLPs), one PCR
(polymerase chain reaction) marker (a sequence coding for a LMW (low-molecular-weight) glutenin subunit gene located at the
Glu-B3 locus), seven biochemical (six seed-storage protein loci and one isozyme locus) and seven morphological markers. A total
of 213 loci were mapped at a LOD≥3 on all 14 chromosomes of the A and B genomes. The total length of the map is 1352 cM and
the average distance between adjacent markers is 6.3 cM. Forty six loci could not be mapped at a LOD≥3. A fraction (18.6%)
of the markers deviated significantly from the expected Mendelian ratios; clusters of loci showing distorted segregation were
found on chromosomes 1B, 3AL, 4AL, 6AL and 7AL. The durum wheat map was compared with the published maps of bread wheat using
several common RFLP markers and general features are discussed. The markers detected the known structural rearrangements involving
chromosomes 4A, 5A and 7B as well as the translocation between 2B-6B, but not the deletion on 2BS. This map provides a useful
tool for analysing and breeding economically important quantitative traits and for marker-assisted selection, as well as for
studies of genome organisation in small grain cereal species.
Received: 5 January 1998 / Accepted: 31 March 1998 相似文献
10.
A. Singh M. S. Negi J. Rajagopal S. Bhatia U. K. Tomar P. S. Srivastava M. Lakshmikumaran 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(1-2):272-279
Genetic diversity was estimated in 37 neem accessions from different eco-geographic regions of India and four exotic lines
from Thailand using AFLP markers. Seven AFLP selective primer combinations generated a total of 422 amplification products.
The average number of scorable fragments was 60 per experiment, and a high degree (69.8%) of polymorphism was obtained per
assay with values ranging from 58% to 83.8%. Several rare and accession-specific bands were identified which could be effectively
used to distinguish the different genotypes. Genetic relationships within the accessions were evaluated by generating a similarity
matrix based on the Jaccard index. The phenetic dendrogram generated by UPGMA as well as principal correspondence analysis
separated the 37 Indian genotypes from the four Thai lines. The cluster analysis indicated that neem germplasm within India
constitutes a broad genetic base with the values of genetic similarity coefficient ranging from 0.74 to 0.93. Also, the Indian
genotypes were more dispersed on the principal correspondence plot, indicating a wide genetic base. The four lines from Thailand,
on the other hand, formed a narrow genetic base with similarity coefficients ranging from 0.88 to 0.92. The lowest genetic
similarity coefficient value (0.47) was observed between an Indian and an exotic genotype. The level of genetic variation
detected within the neem accessions with AFLP analysis suggests that it is an efficient marker technology for delineating
genetic relationships amongst genotypes and estimating genetic diversity, thereby enabling the formulation of appropriate
strategies for conservation and tree improvement programs.
Received: 20 October 1998 / Accepted: 28 November 1998 相似文献
11.
Chimerism in grapevines: implications for cultivar identity,ancestry and genetic improvement 总被引:10,自引:0,他引:10
Franks T Botta R Thomas MR Franks J 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,104(2-3):192-199
In the course of DNA profiling of grapevine cultivars using microsatellite loci we have occasionally observed more than two
alleles at a locus in some individuals and have identified periclinal chimerism as the source of such anomalies. This phenomenon
in long-lived clonally propagated crops, such as grapevine, which contains historically ancient cultivars, may have a role
in clonal differences and affect cultivar identification and pedigree analysis. Here we show that when the two cell layers
of a periclinal chimera, Pinot Meunier, are separated by passage through somatic embryogenesis the regenerated plants not
only have distinct DNA profiles which are different from those of the parent plant but also have novel phenotypes. Recovery
of these phenotypes indicates that additional genetic differences can exist between the two cell layers and that the Pinot
Meunier phenotype is due to the interaction of genetically distinct cell layers. It appears that grapevine chimerism can not
only modify phenotype but can also impact on grapevine improvement as both genetic transformation and conventional breeding
strategies separate mutations in the L1 and L2 cell layers.
Received: 14 March 2001 / Accepted: 22 May 2001 相似文献
12.
J. Garcia-Mas M. Oliver H. Gómez-Paniagua M.C. de Vicente 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(5-6):860-864
Three different types of molecular markers, RAPD, AFLP and RFLP were used to measure genetic diversity among six genotypes
of Cucumis melo L. Each line represented a different melon genotype: Piel de Sapo, Ogen, PI161375, PI414723, Agrestis and C105. A number
of polymorphic RAPD, AFLP and RFLP bands were scored on all materials and the genetic similarity measured. Clustering analysis
performed with the three types of markers separated the genotypes into two main groups: (1) the sweet type, cultivated melons
and (2) the exotic type, not cultivated melons. While the data obtained suggest that all three types of markers are equally
informative, AFLPs showed the highest efficiency in detecting polymorphism.
Received: 30 December 1999 / Accepted: 24 January 2000 相似文献
13.
Microsatellites and RFLP probes from maize are efficient sources of molecular markers for the biomass energy crop Miscanthus 总被引:5,自引:0,他引:5
P. Hernández G. Dorado D. A. Laurie A. Martín J. W. Snape 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(4):616-622
A survey of Gramineae markers was carried out with the aim of developing cost-effective methods for the molecular analysis
of Miscanthus species. Ten out of twenty Gramineae RFLP probes from ”anchor” sets hybridized well to Miscanthus DNA while all 15 maize probes tested cross-hybridized successfully, showing similar patterns in both species. Cross-taxa
amplification of maize microsatellite primers was then tested. This showed that 57 out of 76 (75%) give highly reproducible
amplification with Miscanthus DNA. Amplification products differed in size from those in maize but there was no bias toward higher or lower molecular weights.
Microsatellite polymorphism produced by 17 primer pairs was studied in detail in a panel of 11 Miscanthus clones belonging to the species Miscanthus
sinensis, Miscanthus sacchariflorus, Miscanthus ×giganteus and Miscanthus condensatus. Intra- and inter-specific length polymorphisms were frequent between the tested Miscanthus clones with length polymorphisms being found for all primer pairs, detecting 3–22 alleles. Polymorphism information content
(PIC) values for microsatellites ranged from 0.48 to 0.94 with an average of 0.83. Species-specific amplicons were produced
by two microsatellites. Genetic similarity coefficients of the Miscanthus clones ranged from 0.35 to 0.92, with an average of 0.57. Five polymorphisms were studied in a segregating population, where
they showed Mendelian inheritance. In addition, two microsatellite markers mapping 1.3-cM apart on maize chromosome 7 were
linked in Miscanthus at an estimated distance of 8 cM, suggesting collinearity. The high transferability of microsatellite markers from maize
will enhance the power and resolution of genome analysis in Miscanthus.
Received: 14 April 2000 / Accepted: 9 June 2000 相似文献
14.
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
15.
云南省作物种质资源的研究现状及利用前景 总被引:1,自引:0,他引:1
云南是中国作物种质资源最为丰富的省份之一,已收集保存各类作物种质资源2万余份,并在水稻、小麦、玉米、甘蔗、茶叶、油料、花卉等资源的利用方面开展了一系列的研究,取得了丰硕的成果。本文将在分析云南作物种质资源利用研究的基础上,论述云南作物种质资源在育种、科研、国际交流等方面的利用途径与发展前景。 相似文献
16.
广西地方稻种资源核心种质构建和遗传多样性分析 总被引:1,自引:0,他引:1
以丁颖分类体系分组原则与组内逐层聚类取样方法,对8609份广西地方栽培稻资源表型数据信息进行分析,通过对表型保留比例等评价指标的多重比较确定核心种质总体取样比例,构建出占总体样本5%(414份)的广西地方栽培稻资源初级核心种质。初级核心种质能代表总体遗传变异的89%。用34对SSR分子标记对初级核心种质进行遗传多样性分析,结果表明:广西地方栽培稻资源有较高的遗传多样性(等位基因数A为4.91,Nei’s多样性指数为0.574)。就Nei’s遗传多样性指数而言,粳稻高于籼稻,晚稻高于早稻,水稻高于陆稻,糯稻高于粘稻;来自桂中的稻种资源具有最高的遗传多样性。研究最终利用SSR数据,把414份初级核心种质压缩50%后形成209份核心种质,核心种质基因保留比例达到98%以上,有效代表了广西地方栽培稻资源多样性水平。 相似文献
17.
The use of microsatellites for detecting DNA polymorphism, genotype identification and genetic diversity in wheat 总被引:35,自引:0,他引:35
M. Prasad R. K. Varshney J. K. Roy H. S. Balyan P. K. Gupta 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(3-4):584-592
A set of 20 wheat microsatellite markers was used with 55 elite wheat genotypes to examine their utility (1) in detecting
DNA polymorphism, (2)in the identifying genotypes and (3) in estimating genetic diversity among wheat genotypes. The 55 elite
genotypes of wheat used in this study originated in 29 countries representing six continents. A total of 155 alleles were
detected at 21 loci using the above microsatellite primer pairs (only 1 primer amplified 2 loci; all other primers amplified
1 locus each). Of the 20 primers amplifying 21 loci, 17 primers and their corresponding 18 loci were assigned to 13 different
chromosomes (6 chromosomes of the A genome, 5 chromosomes of the B genome and 2 chromosomes of the D genome). The number of
alleles per locus ranged from 1 to 13, with an average of 7.4 alleles per locus. The values of average polymorphic information
content (PIC) and the marker index (MI) for these markers were estimated to be 0.71 and 0.70, respectively. The (GT)n microsatellites were found to be the most polymorphic. The genetic similarity (GS) coefficient for all possible 1485 pairs
of genotypes ranged from 0.05 to 0.88 with an average of 0.23. The dendrogram, prepared on the basis of similarity matrix
using the UPGMA algorithm, delineated the above genotypes into two major clusters (I and II), each with two subclusters (Ia,
Ib and IIa, IIb). One of these subclusters (Ib) consisted of a solitary genotype (E3111) from Portugal, so that it was unique
and diverse with respect to all other genotypes belonging to cluster I and placed in subcluster Ia. Using a set of only 12
primer pairs, we were able to distinguish a maximum of 48 of the above 55 wheat genotypes. The results demonstrate the utility
of microsatellite markers for detecting polymorphism leading to genotype identification and for estimating genetic diversity.
Received: 15 May 1999 / Accepted: 27 July 1999 相似文献
18.
Comparison of multivariate methods for the analysis of genetic resources and adaptation in Phytolacca dodecandra using RAPD 总被引:2,自引:0,他引:2
K. Semagn A. Bjornstad B. Stedje E. Bekele 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(7):1145-1154
The extent of genetic differentiation among 17 Ethiopian populations (249 individuals) of Phytolacca dodecandra (Endod) sampled along altitudinal gradients that varied from 1600 to 3000 m was investigated using random amplified polymorphic
DNA (RAPD). The populations were classified into three altitude groups: lowland (1600–2100 m), central-highland (2101–2500
m) and highland (2500–3000 m). Seventy polymorphic loci scored from 12 RAPD primers, singly or in combination with ecogeographical
variables (altitude, longitude, latitude, temperature and rainfall), were used for principal component, discriminant, correlation,
and stepwise multiple regression analyses. Principal component analysis (PCA) clearly differentiated lowland and the central-highland
populations from those of the highlands independent of their geographical regions. Canonical discriminant analysis separated
the lowland plants from those of the highlands with the central-highland plants being intermediate. Classificatory discriminant
analysis corrected classification of 92.8% of the 249 plants into their respective three altitude groups. Multiple regression
analysis identified a strong association between some RAPDs and altitude, temperature and rainfall, while the variation in
most RAPDs was explained by combinations of the different ecogeographical variables. It is hypothesised that the different
altitude groups may be (1) chemical and/or physiological ecotypes produced as a result of complex interactions of altitude
with climatic and/or edaphic factors, or (2) different in ploidy levels. The significant correlations obtained between population
means from some RAPDs and altitude and temperature as well as the strong association of some RAPDs with the ecogeographical
variables in the multiple regression analysis suggest that part of the RAPD polymorphism could be adaptive, and responsive
to environmental selection.
Received: 15 December 1999 / Accepted: 12 February 2000 相似文献
19.
S. M. Udupa F. Weigand M. C. Saxena G. Kahl 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(1-2):299-307
The poor definition of variation in the ascochyta blight fungus (Ascochyta rabiei) has historically hindered breeding for resistance to the chickpea (Cicer arietinum L.) blight disease in West Asia and North Africa. We have employed 14 RAPD markers and an oligonucleotide probe complementary
to the microsatellite sequence (GATA)4 to construct a genotype-specific DNA fragment profile from periodically sampled Syrian field isolates of this fungus. By
using conventional pathogenicity tests and genome analysis with RAPD and microsatellite markers, we demonstrated that the
DNA markers distinguish variability within and among the major pathotypes of A. rabiei and resolved each pathotypes into several genotypes. The genetic diversity estimate based on DNA marker analysis within pathotypes
was highest for the least-aggressive pathotype (pathotype I), followed by the aggressive (pathotype II) and the most-aggressive
pathotype (pathotype III). The pair-wise genetic distance estimated for all the isolates varied from 0.00 to 0.39, indicating
a range from a clonal to a diverse relationship. On the basis of genome analysis, and information on the spatial and temporal
distribution of the pathogen, a general picture of A. rabiei evolution in Syria is proposed.
Received: 10 January 1998 / Accepted: 23 January 1998 相似文献
20.
M. Pillay E. Ogundiwin D. C. Nwakanma G. Ude A. Tenkouano 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2001,102(6-7):965-970
The genetic diversity and phylogenetic relationships of 29 East African highland banana (Musa spp.) cultivars and two outgroup taxa, M. acuminata Calcutta 4 and Agbagba were surveyed by RAPD analysis. A genetic similarity matrix was established based on the presence
or absence of polymorphic amplified fragments. Phylogenetic relationships were determined by UPGMA cluster analysis. RAPDs
showed that the highland bananas are closely related with a narrow genetic base. Nevertheless, there were sufficient RAPD
polymorphisms that were collectively useful in distinguishing the cultivars. The dendrogram was divisible into a major cluster
composed of all the AAA highland banana cultivars and Agbagba (AAB) and a minor cluster consisting of Kisubi (AB), Kamaramasenge
(AB) and Calcutta 4 (AA). Several subgroups are recognized within the major cluster. RAPD data did not separate beer and cooking
banana cultivars. Our study showed that RAPD markers can readily dissect genetic differences between the closely related highland
bananas and provide a basis for the selection of parents for improvement of this germplasm.
Received: 28 June 2000 / Accepted: 1 August 2000 相似文献