Untitled

Pagliarini, Maria Suely; Takayama, S.Y.; Freitas, Patrícia matias de; Carraro, L. R.; Adamowski, E V; Silva, N.; Batista, L. A. R.

doi:10.1023/a:1003660327223

Cited by 23 publications

(8 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Accessions from the Paspalum collection used in the whole germplasm analysis. The ID, BRA code, species, botanical groups, origin, chromosome numbers and the reference for the chromosome number determination are shown [23,31,32,114,122-126]. …”

Section: Supplementary Materialsmentioning

confidence: 99%

See 1 more Smart Citation

Genetic variation in polyploid forage grass: Assessing the molecular genetic variability in the Paspalumgenus

et al. 2013

View full text Add to dashboard Cite

BackgroundPaspalum (Poaceae) is an important genus of the tribe Paniceae, which includes several species of economic importance for foraging, turf and ornamental purposes, and has a complex taxonomical classification. Because of the widespread interest in several species of this genus, many accessions have been conserved in germplasm banks and distributed throughout various countries around the world, mainly for the purposes of cultivar development and cytogenetic studies. Correct identification of germplasms and quantification of their variability are necessary for the proper development of conservation and breeding programs. Evaluation of microsatellite markers in different species of Paspalum conserved in a germplasm bank allowed assessment of the genetic differences among them and assisted in their proper botanical classification.ResultsSeventeen new polymorphic microsatellites were developed for Paspalum atratum Swallen and Paspalum notatum Flüggé, twelve of which were transferred to 35 Paspalum species and used to evaluate their variability. Variable degrees of polymorphism were observed within the species. Based on distance-based methods and a Bayesian clustering approach, the accessions were divided into three main species groups, two of which corresponded to the previously described Plicatula and Notata Paspalum groups. In more accurate analyses of P. notatum accessions, the genetic variation that was evaluated used thirty simple sequence repeat (SSR) loci and revealed seven distinct genetic groups and a correspondence of these groups to the three botanical varieties of the species (P. notatum var. notatum, P. notatum var. saurae and P. notatum var. latiflorum).ConclusionsThe molecular genetic approach employed in this study was able to distinguish many of the different taxa examined, except for species that belong to the Plicatula group, which has historically been recognized as a highly complex group. Our molecular genetic approach represents a valuable tool for species identification in the initial assessment of germplasm as well as for characterization, conservation and successful species hybridization.

show abstract

Section: Supplementary Materialsmentioning

confidence: 99%

“…Chromosome number, type of polyploidy, reproduction mode and genomes found in the Paspalum species based on the literature [17,27,30-32,102-104,106-108,110,113,114],[122,124,125,127-157]. …”

Section: Supplementary Materialsmentioning

confidence: 99%

Genetic variation in polyploid forage grass: Assessing the molecular genetic variability in the Paspalumgenus

et al. 2013

View full text Add to dashboard Cite

show abstract

“…This screening method can be used routineously in breeding programs, since only viable unreduced pollen are of importance. 2n pollen producers are characterised by abnormalities during meiosis (Islam and Shepherd 1980;Bretagnolle and Thompson 1995;Pagliarini et al 1999;El Mokadem et al 2002). The identification of the mechanisms behind the formation of unreduced gametes is complex, because different cytological mechanisms may operate within one individual.…”

Section: Observed In Lilies Thatmentioning

confidence: 99%

Occurrence of viable unreduced pollen in a Begonia collection

Dewitte¹,

Eeckhaut²,

Huylenbroeck³

et al. 2009

Euphytica

View full text Add to dashboard Cite

Polyploidy is widespread in plants and has played a major role in the evolution and diversification of the plant kingdom. Unreduced (2n) gametes are an interesting tool for polyploidisation and the creation of genetic variation in plant breeding. Especially in ornamentals, polyploidisation can broaden attractive features within a species. A Begonia collection was screened on the occurrence of 2n pollen with the aid of four different techniques: pollen size measurement, flow cytometric analysis of nuclei isolated from germinated and non germinated pollen, investigation of the microsporogenesis and analysis of progeny. In ten of the 70 screened genotypes (B. dregei, B. pearcei, B. 'Anna Christina', B. 'Bubbles', B. 'Florence Rita', B. 'Orococo', B. 'Rubaiyat', B. 'Spatflacier', B. 'Tamo' and B276), large pollen were observed with a rather spherical than normal ellipsoidal shape. Flow cytometric data proved that these aberrantly shaped pollen were associated with 2n ploidy levels, although they were not always viable. Meiotic aberrations in these large pollen producers resulted mainly in dyads although also monads, triads and polyads were observed. Successful crosses were obtained with B. dregei, B. 'Orococo', and B276 as pollinators; DNA content had increased in all or a part of the progeny. The results show that the occurrence of 2n pollen is not a rare phenomenon in Begonia

show abstract

“…“Lineño” in the second meiotic division caused the formation of dyads and triads, if the absence of cytokinesis was present in both cells of the dyad, then two restituted nuclei were generated and therefore, two 2n gametes; however, if the failure was present in only one of the cells of the dyad then a triad with two n gametes and one 2n gamete was produced. 2n microspores resulting from the absence of cytokinesis have been reported in several genera, such as Paspalum and Brachiaria (Pagliarini et al 1999; Boldrini et al 2006), Solanum spp. (Werner and Peloquin 1987), Lolium (Wagenvoort and Den Nijs 1992) and Medicago (Pfeiffer and Bingham 1983), where the failure in cytokinesis was present in both the first and second meiotic divisions, thus generating dyads and triads.…”

Section: Discussionmentioning

confidence: 99%

Meiotic restitution mechanisms involved in the formation of 2n pollen in Agave tequilana Weber and Agave angustifolia Haw

2012

View full text Add to dashboard Cite

A cytological analysis of the microsporogenesis was carried out in the Agave tequilana and A. angustifolia species. Several abnormalities such as chromosomal bridges, lagging chromosomes, micronuclei, monads, dyads and triads were found. The morphological analysis of the pollen, together with the above-mentioned 2n microspores, allowed us to confirm the presence of 2n pollen as well as its frequency. In both A. tequilana and A. angustifolia two different mechanisms were observed: the first mechanism, a failure in the cytokinesis in meiosis II caused the formation of dyads with two 2n cells and triads containing two n cells and one 2n cell; the second mechanism, involves an abnormal spindle, which caused the formation of triads with two n cells and one 2n cell. Likewise, the presence of monads was detected in both species, these, might be caused by a failure of the cytokinesis in both meiotic divisions. This is the first report about the presence of a Second Division Restitution mechanism (SDR) which causes the formation of 2n pollen in the genus Agave. The genetic implications of the presence of 2n pollen in the genus Agave are discussed.

show abstract

Untitled

Cited by 23 publications

References 25 publications

Genetic variation in polyploid forage grass: Assessing the molecular genetic variability in the Paspalumgenus

Genetic variation in polyploid forage grass: Assessing the molecular genetic variability in the Paspalumgenus

Occurrence of viable unreduced pollen in a Begonia collection

Meiotic restitution mechanisms involved in the formation of 2n pollen in Agave tequilana Weber and Agave angustifolia Haw

Contact Info

Product

Resources

About