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1.
Ferrier-Cana E Geffroy V Macadré C Creusot F Imbert-Bolloré P Sévignac M Langin T 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,106(2):251-261
A complex ancestral resistance (R) gene cluster, localized at the end of linkage group B4, and referred to as the B4 R gene cluster, has been previously genetically characterized. The B4 R gene cluster existed prior to the separation of the two major gene pools of cultivated common bean and contains several resistance specificities effective against the fungus Colletotrichum lindemuthianum. In this paper we report the molecular analysis of four expressed resistance gene candidates (RGCs) that map at the B4 R-cluster and co-localize with R-specificities or R-QTLs effective against C. lindemuthianum. These RGCs have been isolated from two genotypes that are representative of the two major gene pools of common bean: the BA8 and BA11 RGCs originating from the Mesoamerican BAT93 genotype, and the JA71 and JA78 RGCs originating from the Andean JaloEEP558 genotype. These RGCs encode NBS-LRR resistance-like proteins that are closely similar to the tomato I2 R-protein. Based upon sequence comparisons and genetic localization, we established that these four bean RGCs belong to two different subfamilies of R-sequences independently of their gene pool of origin. No feature discriminating the four RGCs according to their gene pool of origin has been observed yet. Comparative sequence analyses of the full-length RGCs and their flanking genomic sequences confirmed the ancestral origin of the B4 R-cluster. 相似文献
2.
Geffroy V Sévignac M Billant P Dron M Langin T 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2008,116(3):407-415
Anthracnose, caused by the hemibiotrophic fungal pathogen Colletotrichum lindemuthianum is a devastating disease of common bean. Resistant cultivars are economical means for defense against this pathogen. In the
present study, we mapped resistance specificities against 7 C. lindemuthianum strains of various geographical origins revealing differential reactions on BAT93 and JaloEEP558, two parents of a recombinant
inbred lines (RILs) population, of Meso-american and Andean origin, respectively. Six strains revealed the segregation of
two independent resistance genes. A specific numerical code calculating the LOD score in the case of two independent segregating
genes (i.e. genes with duplicate effects) in a RILs population was developed in order to provide a recombination value (r) between each of the two resistance genes and the tested marker. We mapped two closely linked Andean resistance genes (Co-x, Co-w) at the end of linkage group (LG) B1 and mapped one Meso-american resistance genes (Co-u) at the end of LG B2. We also confirmed the complexity of the previously identified B4 resistance gene cluster, because four
of the seven tested strains revealed a resistance specificity near Co-y from JaloEEP558 and two strains identified a resistance specificity near Co-9 from BAT93. Resistance genes found within the same cluster confer resistance to different strains of a single pathogen such
as the two anthracnose specificities Co-x and Co-w clustered at the end of LG B1. Clustering of resistance specificities to multiple pathogens such as fungi (Co-u) and viruses (I) was also observed at the end of LG B2. 相似文献
3.
Geffroy V Sévignac M De Oliveira JC Fouilloux G Skroch P Thoquet P Gepts P Langin T Dron M 《Molecular plant-microbe interactions : MPMI》2000,13(3):287-296
Anthracnose, one of the most important diseases of common bean (Phaseolus vulgaris), is caused by the fungus Colletotrichum lindemuthianum. A "candidate gene" approach was used to map anthracnose resistance quantitative trait loci (QTL). Candidate genes included genes for both pathogen recognition (resistance genes and resistance gene analogs [RGAs]) and general plant defense (defense response genes). Two strains of C. lindemuthianum, identified in a world collection of 177 strains, displayed a reproducible and differential aggressiveness toward BAT93 and JaloEEP558, two parental lines of P. vulgaris representing the two major gene pools of this crop. A reliable test was developed to score partial resistance in aerial organs of the plant (stem, leaf, petiole) under controlled growth chamber conditions. BAT93 was more resistant than JaloEEP558 regardless of the organ or strain tested. With a recombinant inbred line (RIL) population derived from a cross between these two parental lines, 10 QTL were located on a genetic map harboring 143 markers, including known defense response genes, anthracnose-specific resistance genes, and RGAs. Eight of the QTL displayed isolate specificity. Two were co-localized with known defense genes (phenylalanine ammonia-lyase and hydroxyproline-rich glycoprotein) and three with anthracnose-specific resistance genes and/or RGAs. Interestingly, two QTL, with different allelic contribution, mapped on linkage group B4 in a 5.0 cM interval containing Andean and Mesoamerican specific resistance genes against C. lindemuthianum and 11 polymorphic fragments revealed with a RGA probe. The possible relationship between genes underlying specific and partial resistance is discussed. 相似文献
4.
Characterization of all chromosomes of the Andean G19833 bean genotype was carried out by fluorescent in situ hybridization. Eleven single-copy genomic sequences, one for each chromosome, two BACs containing subtelomeric and pericentromeric repeats and the 5S and 45S ribosomal DNA (rDNA) were used as probes. Comparison to the Mesoamerican accession BAT93 showed little divergence, except for additional 45S rDNA sites in four chromosome pairs. Altogether, the results indicated a relative karyotypic stability during the evolution of the Andean and Mesoamerican gene pools of P. vulgaris. 相似文献
5.
V Geffroy D Sicard J C de Oliveira M Sévignac S Cohen P Gepts C Neema T Langin M Dron 《Molecular plant-microbe interactions : MPMI》1999,12(9):774-784
The recent cloning of plant resistance (R) genes and the sequencing of resistance gene clusters have shed light on the molecular evolution of R genes. However, up to now, no attempt has been made to correlate this molecular evolution with the host-pathogen coevolution process at the population level. Cross-inoculations were carried out between 26 strains of the fungal pathogen Colletotrichum lindemuthianum and 48 Phaseolus vulgaris plants collected in the three centers of diversity of the host species. A high level of diversity for resistance against the pathogen was revealed. Most of the resistance specificities were overcome in sympatric situations, indicating an adaptation of the pathogen to the local host. In contrast, plants were generally resistant to allopatric strains, suggesting that R genes that were efficient against exotic strains but had been overcome locally were maintained in the plant genome. These results indicated that coevolution processes between the two protagonists led to a differentiation for resistance in the three centers of diversity of the host. To improve our understanding of the molecular evolution of these different specificities, a recombinant inbred (RI) population derived from two representative genotypes of the Andean (JaloEEP558) and Mesoamerican (BAT93) gene pools was used to map anthracnose specificities. A gene cluster comprising both Andean (Co-y; Co-z) and Mesoamerican (Co-9) host resistance specificities was identified, suggesting that this locus existed prior to the separation of the two major gene pools of P. vulgaris. Molecular analysis revealed a high level of complexity at this locus. It harbors 11 restriction fragment length polymorphisms when R gene analog (RGA) clones are used. The relationship between the coevolution process and diversification of resistance specificities at resistance gene clusters is discussed. 相似文献
6.
Thiago Lívio P. O. Souza Everaldo G. de Barros Claudia M. Bellato Eun-Young Hwang Perry B. Cregan Marcial A. Pastor-Corrales 《Molecular breeding : new strategies in plant improvement》2012,30(1):419-428
Single nucleotide polymorphisms (SNPs) were discovered in common bean (Phaseolus vulgaris L.) via resequencing of sequence-tagged sites (STSs) developed by PCR primers previously designed to soybean shotgun and bacterial artificial chromosome (BAC) end sequences, and by primers designed to common bean genes and microsatellite flanking regions. DNA fragments harboring SNPs were identified in single amplicons from six contrasting P. vulgaris genotypes of the Andean (Jalo EEP 558, G 19833, and AND 277) and Mesoamerican (BAT 93, DOR 364, and Rudá) gene pools. These genotypes are the parents of three common bean recombinant inbred line mapping populations. From an initial set of 1,880 PCR primer pairs tested, 265 robust STSs were obtained, which could be sequenced in each one of the six common bean genotypes. In the resulting 131,120?bp of aligned sequence, a total of 677 SNPs were identified, including 555 single-base changes (295 transitions and 260 transversions) and 122 small nucleotide insertions/deletions (indels). The frequency of SNPs was 5.16 SNPs/kb and the mean nucleotide diversity, expressed as Halushka??s theta, was 0.00226. This work represents one of the first efforts aimed at detecting SNPs in P. vulgaris. The SNPs identified should be an important resource for common bean geneticists and breeders for quantitative trait locus discovery, marker-assisted selection, and map-based cloning. These SNPS will be also useful for diversity analysis and microsynteny studies among legume species. 相似文献
7.
Marília Lobo Burle Jaime Roberto Fonseca James A. Kami Paul Gepts 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,121(5):801-813
Brazil is the largest producer and consumer of common bean (Phaseolus vulgaris L.), which is the most important source of human dietary protein in that country. This study assessed the genetic diversity and the structure of a sample of 279 geo-referenced common bean landraces from Brazil, using molecular markers. Sixty-seven microsatellite markers spread over the 11 linkage groups of the common bean genome, as well as Phaseolin, PvTFL1y, APA and four SCAR markers were used. As expected, the sample showed lower genetic diversity compared to the diversity in the primary center of diversification. Andean and Mesoamerican gene pools were both present but the latter gene pool was four times more frequent than the former. The two gene pools could be clearly distinguished; limited admixture was observed between these groups. The Mesoamerican group consisted of two sub-populations, with a high level of admixture between them leading to a large proportion of stabilized hybrids not observed in the centers of domestication. Thus, Brazil can be considered a secondary center of diversification of common bean. A high degree of genome-wide multilocus associations even among unlinked loci was observed, confirming the high level of structure in the sample and suggesting that association mapping should be conducted in separate Andean and Mesoamerican Brazilian samples. 相似文献
8.
Manon M. S. Richard Stéphanie Pflieger Mireille Sévignac Vincent Thareau Sophie Blanchet Yupeng Li Scott A. Jackson Valérie Geffroy 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2014,127(7):1653-1666
Key message
The Co - x anthracnose R gene of common bean was fine-mapped into a 58 kb region at one end of chromosome 1, where no canonical NB-LRR-encoding genes are present in G19833 genome sequence.Abstract
Anthracnose, caused by the phytopathogenic fungus Colletotrichum lindemuthianum, is one of the most damaging diseases of common bean, Phaseolus vulgaris. Various resistance (R) genes, named Co-, conferring race-specific resistance to different strains of C. lindemuthianum have been identified. The Andean cultivar JaloEEP558 was reported to carry Co-x on chromosome 1, conferring resistance to the highly virulent strain 100. To fine map Co-x, 181 recombinant inbred lines derived from the cross between JaloEEP558 and BAT93 were genotyped with polymerase chain reaction (PCR)-based markers developed using the genome sequence of the Andean genotype G19833. Analysis of RILs carrying key recombination events positioned Co-x at one end of chromosome 1 to a 58 kb region of the G19833 genome sequence. Annotation of this target region revealed eight genes: three phosphoinositide-specific phospholipases C (PI-PLC), one zinc finger protein and four kinases, suggesting that Co-x is not a classical nucleotide-binding leucine-rich encoding gene. In addition, we identified and characterized the seven members of common bean PI-PLC gene family distributed into two clusters located at the ends of chromosomes 1 and 8. Co-x is not a member of Co-1 allelic series since these two genes are separated by at least 190 kb. Comparative analysis between soybean and common bean revealed that the Co-x syntenic region, located at one end of Glycine max chromosome 18, carries Rhg1, a major QTL contributing to soybean cyst nematode resistance. The PCR-based markers generated in this study should be useful in marker-assisted selection for pyramiding Co-x with other R genes. 相似文献9.
I. N. Wagara A. W. Mwang'ombe J. W. Kimenju R. A. Buruchara R. Jamnadass P. A. O. Majiwa 《Journal of Phytopathology》2004,152(4):235-242
Genetic diversity of 50 Phaeoisariopsis griseola isolates collected from different agroecological zones in Kenya was studied using group‐specific primers and amplified fragment length polymorphism (AFLP) markers. Group‐specific primers differentiated the isolates into Andean and Mesoamerican groups, corresponding to the two common‐bean gene pools. Significant polymorphisms were observed with all the AFLP primer combinations used, reflecting a wide genetic diversity in the P. griseola population. A total of 207 fingerprints was generated, of which 178 were polymorphic. Cluster analysis of the polymorphic bands also separated the isolates into the two groups defined by group‐specific primers. All the isolates examined were grouped into three virulence populations; Andean, Afro‐Andean and Mesoamerican, and their genetic diversity measured. On average, greater diversity (91%) was detected within populations than between populations (9%). The genetic distance between Andean and Mesoamerican populations was higher (D = 0.0269) than between Andean and Afro‐Andean (D = 0.0095). The wide genetic diversity reported here has significant implications in breeding for resistance to angular leaf spot and should be taken into consideration when screening and deploying resistant bean genotypes. 相似文献
10.
11.
The common bean (Phaseolus vulgaris) is one of the most important crop plants. About 50% of its genome is composed of repetitive sequences, but only a little
fraction was isolated and characterized so far. In this paper, a new repetitive DNA family from the species, named PvMeso, was isolated and characterized in both gene pools of P. vulgaris (Andean and Mesoamerican) and related species. Two fragments, 1.7 and 2.3 kb long, were cloned from BAC 255F18, which has
previously shown a repetitive pattern. The subclone PvMeso-31 showed a terminal block in chromosome 7. This subclone contains a 1,705 bp long, AT-rich repeat with small internal
repeats and shares a 1.2 kb region with PvMeso-47, derived from the 2.3 kb fragment. The presence of this repetitive block was restricted to Mesoamerican accessions
of the common bean. In P. acutifolius, P. leptostachyus and Andean P. vulgaris, only a faint, 2.3 kb fragment was visualized in Southern experiments. Moreover, in Mesoamerican accessions, two other fragments
(1.7 kb and 3.4 kb) were strongly labelled as well. Taken together, our results indicate that PvMeso is a recently emerged, repeat family initially duplicated in chromosome 11, on ancestral Mesoamerican accession, and
later amplified in chromosome 7, after the split of the two major gene pools of the common bean. 相似文献
12.
Structure of genetic diversity in the two major gene pools of common bean (Phaseolus vulgaris L., Fabaceae) 总被引:1,自引:0,他引:1
Myounghai Kwak Paul Gepts 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(5):979-992
Domesticated materials with well-known wild relatives provide an experimental system to reveal how human selection during
cultivation affects genetic composition and adaptation to novel environments. In this paper, our goal was to elucidate how
two geographically distinct domestication events modified the structure and level of genetic diversity in common bean. Specifically,
we analyzed the genome-wide genetic composition at 26, mostly unlinked microsatellite loci in 349 accessions of wild and domesticated
common bean from the Andean and Mesoamerican gene pools. Using a model-based approach, implemented in the software STRUCTURE,
we identified nine wild or domesticated populations in common bean, including four of Andean and four of Mesoamerican origins.
The ninth population was the putative wild ancestor of the species, which was classified as a Mesoamerican population. A neighbor-joining
analysis and a principal coordinate analysis confirmed genetic relationships among accessions and populations observed with
the STRUCTURE analysis. Geographic and genetic distances in wild populations were congruent with the exception of a few putative
hybrids identified in this study, suggesting a predominant effect of isolation by distance. Domesticated common bean populations
possessed lower genetic diversity, higher F
ST, and generally higher linkage disequilibrium (LD) than wild populations in both gene pools; their geographic distributions
were less correlated with genetic distance, probably reflecting seed-based gene flow after domestication. The LD was reduced
when analyzed in separate Andean and Mesoamerican germplasm samples. The Andean domesticated race Nueva Granada had the highest
F
ST value and widest geographic distribution compared to other domesticated races, suggesting a very recent origin or a selection
event, presumably associated with a determinate growth habit, which predominates in this race.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
13.
A. Maquet I. Zoro Bi M. Delvaux B. Wathelet J.-P. Baudoin 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(5-6):980-991
Genetic diversity and structure within a Lima bean (Phaseolus lunatus L.) base collection have been evaluated using allozyme markers. The results obtained from the analysis of wild and cultivated
accessions confirm the existence of Andean and Mesoamerican gene pools characterised by specific alleles. Wild and cultivated
accessions of the same gene pool are grouped. The Andean natural populations have a very limited geographic distribution between
Ecuador and northern Peru. The Mesoamerican wild form extends from Mexico up to Argentina through the eastern side of the
Andes. Andean and Mesoamerican cultivated accessions of pantropical distribution contribute substantially to the genetic diversity
of the Lima bean base collection. Population genetic parameters, estimated from allozymes, confirmed the predominant selfing
mating system of the Lima bean. The selfing mating system, the occurrence of small populations, and low gene flow lead to
an interpopulation gene diversity (DST=0.235) higher than the intrapopulation gene diversity (HS=0.032). On the basis of the results, guidelines are given to preserve and exploit the genetic diversity of this threatened
species. The results also confirm the independent domestication of the Lima bean in at least two centres, one of which is
located at medium elevation in the western valleys of Ecuador and northern Peru.
Received: 3 June 1997 / Accepted: 17 June 1997 相似文献
14.
Kami J Poncet V Geffroy V Gepts P 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(6):987-998
The APA family of seed proteins consists of three subfamilies, in evolutionary order of hypothesized appearance: phytohaemagglutinins
(PHA), α-amylase inhibitors (αAI), and arcelins (ARL). The APA family plays a defensive role against mammalian and insect
seed predation in common bean (Phaseolus vulgaris L.). The main locus (APA) for this gene family is situated on linkage group B4. In order to elucidate the pattern of duplication and diversification
at this locus, we developed a BAC library in each of four different Phaseolus genotypes that represent presumptive steps in the evolutionary diversification of the APA family. Specifically, BAC libraries
were established in one P. lunatus (cv. ‘Henderson: PHA+ αAI− ARL−) and three P. vulgaris accessions (presumed ancestral wild G21245 from northern Peru: PHA+ αAI + ARL−; Mesoamerican wild G02771: PHA+ αAI + ARL+; and Mesoamerican breeding line BAT93: PHA+ αAI + ARL−). The libraries were constructed after HindIII digestion of high molecular weight DNA, obtained with a novel nuclei isolation procedure. The frequency of empty or cpDNA-sequence-containing
clones in all libraries is low (generally <1%). The Henderson, G21245, and G02771 libraries have a 10× genome coverage, whereas
the BAT93 library has a 20× coverage to allow further, more detailed genomic analysis of the bean genome. The complete sequence
of a 155 kbp-insert clone of the G02771 library revealed six sequences belonging to the APA gene family, including members
of the three subfamilies, as hypothesized. The different subfamilies were interspersed with retrotransposon sequences. In
addition, other sequences were identified with similarity to chloroplast DNA, a dehydrin gene, and the Arabidopsis flowering
D locus. Linkage between the dehydrin gene and the D1711 RFLP marker identifies a potential syntenic region between parts of common bean linkage group B4 and cowpea linkage group
2 相似文献
15.
Sparvoli Francesca Lanave Cecilia Santucci Annalisa Bollini Roberto Lioi Lucia 《Plant molecular biology》2001,45(5):587-597
Lectin-related polypeptides are a class of defence proteins found in seeds of Phaseolus species. In Lima bean (P. lunatus), these proteins and their genes have been well characterized in the Andean morphotype, which represents one of the two gene pools of this species. To study the molecular evolution of the lectin family in Lima bean we characterized the polypeptides belonging to this multigene family and cloned the genes belonging to the Mesoamerican gene pool. The latter gene pool contains components similar to those of the Andean pool, namely: an amylase inhibitor-like (AIL), an arcelin-like (ARL) lectin and the less abundant Lima bean lectin (LBL). These proteins originate from an ancestor gene of the lectin type which duplicated to yield the lectin gene and the progenitor of ARL and AIL. In this species. ARL represents an evolutionary intermediate form that precedes AIL. Phylogenetic analysis supports an Andean origin for Lima bean. The molecular evolutionary studies were extended to the genes of common bean and demonstrated that true lectin genes and the ancestor of lectin-related genes are the result of a duplication event that occurred before speciation. Lima and common bean followed different evolutionary pathways and in the latter species a second duplication event occurred that gave rise, in Mesoamerican wild genotypes, to arcelin genes. 相似文献
16.
S. A. Angioi D. Rau G. Attene L. Nanni E. Bellucci G. Logozzo V. Negri P. L. Spagnoletti Zeuli R. Papa 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,121(5):829-843
This study focuses on the expansion of Phaseolus vulgaris in Europe. The pathways of distribution of beans into and across Europe were very complex, with several introductions from
the New World that were combined with direct exchanges between European and other Mediterranean countries. We have analyzed
here six chloroplast microsatellite (cpSSR) loci and two unlinked nuclear loci (for phaseolin types and Pv-shatterproof1). We have assessed the genetic structure and level of diversity of a large collection of European landraces of P. vulgaris (307) in comparison to 94 genotypes from the Americas that are representative of the Andean and Mesoamerican gene pools.
First, we show that most of the European common bean landraces (67%) are of Andean origin, and that there are no strong differences
across European regions for the proportions of the Andean and Mesoamerican gene pools. Moreover, cytoplasmic diversity is
evenly distributed across European regions. Secondly, the cytoplasmic bottleneck that was due to the introduction of P. vulgaris into the Old World was very weak or nearly absent. This is in contrast to evidence from nuclear analyses that have suggested
a bottleneck of greater intensity. Finally, we estimate that a relatively high proportion of the European bean germplasm (about
44%) was derived from hybridization between the Andean and Mesoamerican gene pools. Moreover, although hybrids are present
everywhere in Europe, they show an uneven distribution, with high frequencies in central Europe, and low frequencies in Spain
and Italy. On the basis of these data, we suggest that the entire European continent and not only some of the countries therein
can be regarded as a secondary diversification center for P. vulgaris. Finally, we outline the relevance of these inter-gene pool hybrids for plant breeding. 相似文献
17.
An investigation was made of the phylogenetic relationships among wild accessions of Lima bean (Phaseolus lunatus) and wild allies of Mesoamerican and Andean origins, using electrophoresis of seed storage proteins and isozymes. Mesoamerican wild species are phylogenetically more distant fromP. lunatus than Andean species, and apparently belong to the tertiary gene pool of Lima bean. The Andean wild species, which are investigated for the first time, reveal a high similarity to the Lima bean, and particularly with its Mesoamerican gene pool. These Andean species probably constitute a secondary gene pool of Lima bean, and are thus of considerable interest in the context of genetic improvement of the crop. Based on these observations, an Andean origin is suggested for the Andean wild species and forP. lunatus. These results point out the importance of collecting and conserving AndeanPhaseolus germplasm. 相似文献
18.
Tania Gioia Giuseppina Logozzo Giovanna Attene Elisa Bellucci Stefano Benedettelli Valeria Negri Roberto Papa Pierluigi Spagnoletti Zeuli 《PloS one》2013,8(10)
Common bean diversity within and between Mesoamerican and Andean gene pools was compared in 89 landraces from America and 256 landraces from Europe, to elucidate the effects of bottleneck of introduction and selection for adaptation during the expansion of common bean (Phaseolus vulgaris L.) in Europe. Thirteen highly polymorphic nuclear microsatellite markers (nuSSRs) were used to complement chloroplast microsatellite (cpSSRs) and nuclear markers (phaseolin and Pv-shatterproof1) data from previous studies. To verify the extent of the introduction bottleneck, inter-gene pool hybrids were distinguished from “pure” accessions. Hybrids were identified on the basis of recombination of gene pool specific cpSSR, phaseolin and Pv-shatterproof1 markers with a Bayesian assignments based on nuSSRs, and with STRUCTURE admixture analysis. More hybrids were detected than previously, and their frequency was almost four times larger in Europe (40.2%) than in America (12.3%). The genetic bottleneck following the introduction into Europe was not evidenced in the analysis including all the accessions, but it was significant when estimated only with “pure” accessions, and five times larger for Mesoamerican than for Andean germplasm. The extensive inter-gene pool hybridization generated a large amount of genotypic diversity that mitigated the effects of the bottleneck that occurred when common bean was introduced in Europe. The implication for evolution and the advantages for common bean breeding are discussed. 相似文献
19.
Genetic variation inPhaseolus lunatus (Lima bean) was investigated at isozyme and DNA levels. Sixty cultivated accessions, including representatives of the Mesoamerican and Andean gene pools and intermediate types, were analyzed for variability at 17 isozyme loci. Some accessions were also examined for restriction fragment length polymorphism (RFLP) at the rDNA level. These data were used to construct two dendrograms showing clear separation in two distinct groups corresponding to each of the gene pools and an intermediate one probably representing a transitional group. 相似文献
20.
María De La Fuente Ana M. González Antonio M. De Ron Marta Santalla 《Molecular breeding : new strategies in plant improvement》2013,31(3):501-516
Most studies on the genetic diversity of common bean (Phaseolus vulgaris L.) have focussed on accessions from the Mesoamerican gene pool compared to the Andean gene pool. A deeper knowledge of the genetic structure of Argentinian germplasm would enable researchers to determine how the Andean domestication event affected patterns of genetic diversity in domesticated beans and to identify candidates for genes targeted by selection during the evolution of the cultivated common bean. A collection of 116 wild and domesticated accessions representing the diversity of the Andean bean in Argentina was genotyped by means of 114 simple sequence repeat (SSR) markers. Forty-seven Mesoamerican bean accessions and 16 Andean bean accessions representing the diversity of Andean landraces and wild accessions were also included. Using the Bayesian algorithm implemented in the software STRUCTURE we identified five major groups that correspond to Mesoamerican and Argentinian wild accessions and landraces and a group that corresponds to accessions from different Andean and Mesoamerican countries. The neighbour-joining algorithm and principal coordinate clustering analysis confirmed the genetic relationships among accessions observed with the STRUCTURE analysis. Argentinian accessions showed a substantial genetic variation with a considerable number of unique haplotypes and private alleles, suggesting that they may have played an important role in the evolution of the species. The results of statistical analyses aimed at identifying genomic regions with consistent patterns of variation were significant for 35 loci (~20 % of the SSRs used in the Argentinian accessions). One of these loci mapped in or near the genomic region of the glutamate decarboxylase gene. Our data characterize the population structure of the Argentinian germplasm. This information on its diversity will be very valuable for use in introgressing Argentinian genes into commercial varieties because the majority of present-day common bean varieties are of Andean origin. 相似文献