Genome differentiation, natural hybridisation and taxonomic relationships among Eleocharis viridans, E. niederleinii and E. ramboana (Cyperaceae)

2017 ◽  
Vol 30 (2) ◽  
pp. 183 ◽  
Author(s):  
Carlos Roberto Maximiano da Silva ◽  
Thaíssa Boldieri de Souza ◽  
Rafael Trevisan ◽  
María Socorro González-Elizondo ◽  
José Marcelo Domingues Torezan ◽  
...  
Keyword(s):  
Random Amplified Polymorphic Dna ◽  
In Situ Hybridisation ◽  
Analysis Data ◽  
Rdna Site ◽  
Genetic Groups ◽  
Genomic In Situ Hybridisation ◽  
35S Rdna ◽  
Natural Hybridisation ◽  
Taxonomic Approach ◽  
Numerical Variation

The role of natural hybridisation and genome changes in the differentiation and speciation of Eleocharis (Cyperaceae) was addressed through the study of the following three closely related species of the polyphyletic series Tenuissimae: Eleocharis viridans Kük. ex Osten, E. ramboana R.Trevis & Boldrini and E. niederleinii Boech., which often reproduce asexually. Molecular and cytogenetic data were used to understand the genomic and karyotypic relationships in the group. Genomes were compared using internal transcribed spacer–cleaved amplified polymorphic sequence (ITS-CAPS) marker and confirmed with random amplified polymorphic DNA, which allowed identification of different genetic groups, with clear evidence of natural hybrids. Karyotype analysis showed numerical variation from 2n = 20–42, with occurrence of chromosome heteromorphisms and polymorphisms, including variability in 35S rDNA site numbers. Meiotic studies demonstrated irregular pairing in some samples, which is associated with hybridisation and asexual reproduction. Genomic in situ hybridisation (GISH) reactions were conducted using two well defined genetic groups as probes, with 2n = 20 and normal meiosis. Probes were tested against each one of the genetic groups and showed positive, partial and negative GISH results, which supported the molecular analysis data. The results indicated that the three studied species are undergoing an intense process of genomic and karyotypic re-arrangement, which results in overlapping of morphological and genomic characteristics. The present study has exemplified the value of an integrative taxonomic approach to solve conflicts in species delimitation in groups undergoing hybridisation.

Effects of the diploidisation process upon the 5S and 35S rDNA sequences in the allopolyploid species of the Dilatata group of Paspalum (Poaceae, Paniceae)

2019 ◽  
Vol 67 (7) ◽  
pp. 521
Author(s):  
Magdalena Vaio ◽  
Cristina Mazzella ◽  
Marcelo Guerra ◽  
Pablo Speranza
Keyword(s):  
Evolutionary Dynamics ◽  
In Situ Hybridisation ◽  
5S Rdna ◽  
Its Region ◽  
Variable Number ◽  
Rrna Genes ◽  
Fluorescence In Situ Hybridisation ◽  
Rdna Sites ◽  
35S Rdna ◽  
Genome Restructuring

The Dilatata group of Paspalum includes species and biotypes native to temperate South America. Among them, five sexual allotetraploids (x = 10) share the same IIJJ genome formula: P. urvillei Steud, P. dasypleurum Kunze ex Desv., P. dilatatum subsp. flavescens Roseng., B.R. Arrill. & Izag., and two biotypes P. dilatatum Vacaria and P. dilatatum Virasoro. Previous studies suggested P. intermedium Munro ex Morong & Britton and P. juergensii Hack. or related species as their putative progenitors and donors of the I and J genome, respectively, and pointed to a narrow genetic base for their maternal origin. It has not yet been established whether the various members of the Dilatata group are the result of a single or of multiple allopolyploid formations. Here, we aimed to study the evolutionary dynamics of rRNA genes after allopolyploidisation in the Dilatata group of Paspalum and shed some light into the genome restructuring of the tetraploid taxa with the same genome formula. We used double target fluorescence in situ hybridisation of 35S and 5S rDNA probes and sequenced the nrDNA internal transcribed spacer (ITS) region. A variable number of loci at the chromosome ends were observed for the 35S rDNA, from 2 to 6, suggesting gain and loss of sites. For the 5S rDNA, only one centromeric pair of signals was observed, indicating a remarkable loss after polyploidisation. All ITS sequences generated were near identical to the one found for P. intermedium. Although sequences showed a directional homogeneisation towards the putative paternal progenitor in all tetraploid species, the observed differences in the number and loss of rDNA sites suggest independent ongoing diploidisation processes in all taxa and genome restructuring following polyploidy.

Genome structure and evolution in the allohexaploid weed Avena fatua L. (Poaceae)

Genome ◽  
1999 ◽  
Vol 42 (3) ◽  
pp. 512-518 ◽  
Author(s):  
Q Yang ◽  
L Hanson ◽  
M D Bennett ◽  
I J Leitch
Keyword(s):  
Ribosomal Dna ◽  
Genomic Structure ◽  
In Situ Hybridisation ◽  
Avena Fatua ◽  
The Other ◽  
Morphological Data ◽  
Avena Species ◽  
Intergenomic Translocations ◽  
Genomic In Situ Hybridisation

Allohexaploid wild oat, Avena fatua L. (Poaceae; 2n = 6x = 42), is one of the world's worst weeds, yet unlike some of the other Avena hexaploids, its genomic structure has been relatively little researched. Consequently, in situ hybridisation was carried out on one accession of A. fatua using an 18S-25S ribosomal DNA (rDNA) sequence and genomic DNA fromA. strigosa (AA-genome diploid) and A. clauda (CC-genome diploid) as probes. Comparing these results with those for other hexaploids studied previously: (i) confirmed that the genomic composition of A. fatua was similar to the other hexaploid Avena taxa (i.e., AACCDD), (ii) identified major sites of rDNA on three pairs of A/D-genome chromosomes, in common with other Avena hexaploids, and (iii) revealed eight chromosome pairs carrying intergenomic translocations between the A/D- and C-genomes in the accession studied. Based on karyotype structure, the identity of some of these recombinant chromosomes was proposed, and this showed that some of these could be divided into two types, (i) those common to all hexaploid Avena species analysed (3 translocations) and (ii) one translocation in this A. fatua accession not previously observed in reports on other hexaploid Avena species. If this translocation is found to be unique to A. fatua, then this information, combined with more traditional morphological data, will add support to the view that A. fatua is genetically distinct from other hexaploid Avena species and thus should retain its full specific status.Key words: wild oats, Avena, genomic in situ hybridisation (GISH), intergenomic translocations, ribosomal DNA.

Random amplified polymorphic DNA fingerprints of the eight taxa of Trichinella and their comparison with allozyme analysis

Parasitology ◽  
1995 ◽  
Vol 110 (4) ◽  
pp. 401-407 ◽  
Author(s):  
C. Bandi ◽  
G. la Rosa ◽  
M. G. Bardin ◽  
G. Damiani ◽  
S. Comincini ◽  
...  
Keyword(s):  
Random Amplified Polymorphic Dna ◽  
Biological Data ◽  
Allozyme Data ◽  
Routine Identification ◽  
Muscle Larvae ◽  
Rapd Fingerprints ◽  
Polymerase Chain ◽  
Taxonomic Approach ◽  
Pcr Conditions

SUMMARYEight taxa have recently been proposed as being encompassed by the genus Trichinella on the basis of allozyme and biological data. In this paper we show that an analogous 8 taxon structure for this genus results from the random amplified polymorphic DNAs (RAPDs). Five 10-mer or 20-mer primers were used under different polymerase chain reaction (PCR) conditions to produce multiband RAPD fingerprints from muscle larvae of 40 isolates of Trichinella spp. The resulting RAPD data were analysed following the numerical taxonomic approach, and the resulting classification was compared to that derived from allozyme data. The agreement found between allozymes and RAPDs, while supporting the polyspecific structure of the genus Trichinella, confirms the potential of RAPDs as a tool for the detection of cryptic species. The selected primers were tested on individual muscle larvae in an attempt to standardize a RAPD assay for the routine identification of the 8 taxa of Trichinella. Only 1 of the 5 primers yielded reproducible fingerprints from the single larvae. Using this primer, the 5 species and the 3 other taxa of the genus Trichinella can be identified in a single assay without the need for massive in vivo parasite production.

scholarly journals Presence and Persistence of Legionella spp. in Groundwater

2005 ◽  
Vol 71 (2) ◽  
pp. 663-671 ◽  
Author(s):  
Joana Costa ◽  
Igor Tiago ◽  
Milton S. da Costa ◽  
António Veríssimo
Keyword(s):  
Legionella Pneumophila ◽  
Random Amplified Polymorphic Dna ◽  
Acid Methyl Ester ◽  
Gene Exchange ◽  
Rapd Profile ◽  
Genetic Groups ◽  
Acid Methyl ◽  
Groundwater Samples ◽  
Rapd Pcr ◽  
Reference Strains

ABSTRACT Groundwater samples (111) from six different boreholes located in two geographical areas were examined for the presence of legionellae over a 7-year period. The number of Legionella isolates detected was generally low. The colonization of the aquifers was not uniform, and the persistence of Legionella was independent of the hydraulic pumps and the plumbing system present in the borehole. A total of 374 isolates identified by fatty acid methyl ester analysis belonged to Legionella pneumophila, L. oakridgensis, L. sainthelensi, and L. londiniensis. In area 1, L. oakridgensis constituted the major population detected, exhibiting only one random amplified polymorphic DNA (RAPD)-PCR profile. L. sainthelensi strains were less frequently isolated and also displayed a single RAPD profile, while L. pneumophila was only sporadically detected. In contrast, L. pneumophila comprised the vast majority of the isolates in area 2 and exhibited six distinct RAPD patterns, indicating the presence of different genetic groups; three L. londiniensis RAPD types were also detected. Two of the L. pneumophila and one of the L. londiniensis RAPD types were persistent in this environment for at least 12 years. The genetic structure of L. pneumophila groundwater populations, inferred from rpoB and dotA gene sequences, was peculiar, since the majority of the isolates were allied in a discrete group different from the lineages containing most of the type and reference strains of the three subspecies of L. pneumophila. Furthermore, gene exchange events related to the dotA allele could be envisioned.

scholarly journals Breeding Aspects of Selected Ornamental Bulbous Crops

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1709
Author(s):  
Agnieszka Marasek-Ciolakowska ◽  
Dariusz Sochacki ◽  
Przemysław Marciniak
Keyword(s):  
Genetic Diversity ◽  
In Situ Hybridisation ◽  
Flower Colour ◽  
Genetic Fidelity ◽  
Vase Life ◽  
Interspecific Hybridisation ◽  
In Vitro Techniques ◽  
Genomic In Situ Hybridisation ◽  
Molecular Cytogenetic Techniques

This article provides an overview of the origin, genetic diversity and methods and trends in breeding of selected ornamental geophytes (Lilium, Tulipa, Narcissus and Hippeastrum). The role of interspecific hybridisation and polyploidisation in assortment development is reviewed. A great variety of cultivars with traits of interest have been generated over the last century by using classical breeding. Geophyte breeders have been interested in a diversity of traits, including resistance to diseases, flower colour and shape, long lasting flowering and a long vase life. Shortening the long breeding process of many geophytes by reducing the juvenile phase and using in vitro techniques are reviewed. Currently, the breeding process has been enhanced by using modern molecular cytogenetic techniques. Genomic in situ hybridisation is frequently used, among other techniques, for genome differentiation in interspecific hybrids, and for assessment of the extent of intergenomic recombination in backcross progenies. Furthermore, several molecular marker techniques are used for verification of hybrid status, identification of genetic diversity, confirmation of the genetic fidelity of in vitro propagated plants and construction of high-density linkage maps. Recently, a myriad of new plant breeding technologies, such as cisgenetics and genome editing technologies have been used to improve the traits of ornamental geophytes, an endeavour that is discussed here. Breeding trends, cultivar novelties as well a new cultivars registered by international authorities during the last five years are presented in detail.

scholarly journals Introgression of yellow flower colour in Buddleja davidii by means of polyploidisation and interspecific hybridisation

2011 ◽  
Vol 38 (No. 3) ◽  
pp. 96-103 ◽  
Author(s):  
K. Van Laere ◽  
J. Van Huylenbroeck ◽  
E. Van Bockstaele
Keyword(s):  
Chromosome Doubling ◽  
In Situ Hybridisation ◽  
Flower Colour ◽  
Plant Morphology ◽  
F1 Hybrids ◽  
Interspecific Crosses ◽  
Interspecific Hybridisation ◽  
Yellow Colour ◽  
Buddleja Davidii ◽  
Genomic In Situ Hybridisation

To introduce yellow colour in the commercial Buddleja davidii (2n = 4x = 76) assortment, an interspecific breeding programme with B. globosa (2n = 2x = 38) was started. The first step was to perform chromosome doubling in B. globosa. Two of the obtained tetraploid B. globosa plants were subsequently used as male parent in interspecific crosses with the white flowering B. davidii cv. Nanhoensis Alba. In total 182 interspecific crosses were made and 18 F1 hybrids were obtained. Genome size measurements, chromosome counts and genomic in situ hybridisation (GISH) analysis proved the hybrid nature of most of the F1 hybrids. Plant morphology also expressed hybrid characteristics. F1 seedlings inherited the yellowish flower colour from B. globosa. As for many other woody ornamentals, the creation of hybrids through interspecific hybridisation along with polyploidisation offers new opportunities for breeding in Buddleja.

scholarly journals Characterization of Phytophthora capsici Isolates from Processing Pumpkin in Illinois

Plant Disease ◽  
2005 ◽  
Vol 89 (2) ◽  
pp. 191-197 ◽  
Author(s):  
S. Z. Islam ◽  
M. Babadoost ◽  
K. N. Lambert ◽  
A. Ndeme ◽  
H. M. Fouly
Keyword(s):  
Mating Type ◽  
Random Amplified Polymorphic Dna ◽  
Phytophthora Capsici ◽  
Group Analysis ◽  
Genetic Distances ◽  
Growth Patterns ◽  
Pair Group ◽  
Genetic Groups ◽  
The Mean

This study was conducted to investigate pathogenic, morphologic, and genetic variations among Phytophthora capsici isolates from processing pumpkin (Cucurbita moschata) fields in Illinois. Random amplified polymorphic DNA (RAPD) markers were employed to assess genetic variation among 24 isolates of P. capsici from 10 individual fields at six locations. Unweighted mean pair group analysis clustered isolates into six groups. The genetic distances ranged from 0.03 to 0.45. Inoculation of pumpkin seedlings in the greenhouse revealed that the isolates belonged to six distinct genetic groups differing significantly (P = 0.05) in virulence. Isolates tested exhibited four growth patterns in culture: cottony, rosaceous, petaloid, and stellate. P. capsici isolates, including an ATCC isolate (ATCC-15427), with cottony growth pattern did not grow at 36°C. The mean oospore diameter of A1 mating type isolates was greater than that of A2 mating type isolates. Nine of 24 isolates tested produced chlamydospores in V8-CaCO3 liquid medium.

Interspecific chromosomal rearrangements in monosomic addition lines of Allium

Genome ◽  
2001 ◽  
Vol 44 (5) ◽  
pp. 929-935 ◽  
Author(s):  
L Barthes ◽  
A Ricroch
Keyword(s):  
Genomic Dna ◽  
Chromosomal Rearrangements ◽  
In Situ Hybridisation ◽  
Crossing Over ◽  
Dna Repeats ◽  
Addition Lines ◽  
Genomic In Situ Hybridisation ◽  
Chromatin Transfer ◽  
Alien Addition Lines

Monosomic alien addition lines (MAALs) are useful for assigning linkage groups to chromosomes. We examined whether the chromosomal rearrangements following the introduction of a single onion (Allium cepa) chromosome into the Allium fistulosum genome were produced by homeologous crossing over or by a nonreciprocal conversion event. Among the monosomic lines available, 17 were studied by fluorescent genomic in situ hybridisation, using total A. cepa genomic DNA as the probe and total A. fistulosum genomic DNA as the competitor. In this way, rearrangements such as chromosomal translocations between A. cepa and A. fistulosum were identified as terminal regions consisting of tandem DNA repeats. Homeologous crossing over between the two closely related genomes occurred in 4 of the 17 lines, suggesting that such events are not rare. On the basis of a detailed molecular cytogenetic characterisation, we identified true monosomic alien addition lines for A. cepa chromosomes 3, 4, 5, 7, and 8 that can reliably be used in genetic studies.Key words: chromatin transfer, genomic in situ hybridisation, GISH, monosomic alien addition lines, MAALs, Allium.

Genetic differentiation among and within three red mahoganies (series Annulares), Eucalyptus pellita, E. resinifera and E. scias (Myrtaceae)

2009 ◽  
Vol 22 (5) ◽  
pp. 332 ◽  
Author(s):  
Son Le ◽  
Catherine Nock ◽  
Michael Henson ◽  
Mervyn Shepherd
Keyword(s):  
Ecological Factors ◽  
Taxonomic Status ◽  
Genetic Structuring ◽  
Eucalyptus Pellita ◽  
Genetic Groups ◽  
Commercial Species ◽  
Biogeographical Regions ◽  
Natural Hybridisation ◽  
Cape York ◽  
The Relationship

The red mahogany group (Eucalyptus ser. Annulares Blakely) includes some of the most important commercial species (i.e. Eucalyptus urophylla S.T.Blake) worldwide for forestry in the subtropics and tropics. However, the taxonomic status of some species in this group is unclear and the relationship among and genetic structuring within some species is unresolved. The present study examined genetic variation at 13 microsatellite loci in E. pellita F.Muell., E. resinifera Smith and E. scias L.Johnson & K.Hill. Despite close geographical proximity and natural hybridisation in northern Queensland, E. resinifera and E. pellita remain genetically distinct as taxa. Within E. pellita, two genetic groups were clearly resolved, one from New Guinea and one from Queensland (Cape York Peninsula populations were not sampled). Geographic structuring was also evident in E. resinifera, with northern Queensland populations separating from those from Fraser Island southwards. Ecological factors and species disjunctions were implicated in the genetic substructuring of these two taxa because patterns of geographic variation aligned with biogeographical regions. E. scias was indistinguishable from southern E. resinifera and its three subspecies could not be resolved.

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