Polyploidy and evolution in plants.

Wendel, Jonathan F.; Doyle, J Eff J.; Henry, Robert J

doi:10.1079/9780851999043.0097

Cited by 91 publications

(75 citation statements)

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“…Relatively little is known about the genetic and functional consequences of uniting two divergent genetic systems into a common nucleus in only one parental cytoplasm (Wendel and Doyle, 2005). A critical period in this process is during and immediately after allopolyploid formation, when two distinct genomes are first brought into contact, thereby requiring a diverse array of accommodation (Liu et al, 2001).…”

Section: Resultsmentioning

confidence: 99%

“…Some evidence indicates that both autopolyploidy and allopolyploidy are common in nature, and that the latter probably predominates (Ramsey and Schemske, 1998;Soltis et al, 2004;Wendel and Doyle, 2005).…”

Section: Introductionmentioning

confidence: 99%

“…Traditionally, polyploidy refers to either duplication of a single genome (autopolyploidy) or to the combination of two or more differentiated genomes (allopolyploidy) (Wendel and Doyle, 2005). Some evidence indicates that both autopolyploidy and allopolyploidy are common in nature, and that the latter probably predominates (Ramsey and Schemske, 1998;Soltis et al, 2004;Wendel and Doyle, 2005).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Genome elimination during microsporogenesis in two pentaploid accessions of Brachiaria decumbens (Poaceae)

Ricci¹,

Pagliarini²,

Valle³

2010

Genet. Mol. Res.

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ABSTRACT. Polyploidy is a prominent and significant force in plant evolution, taking place since ancient times and continuing until today. Recent cytogenetic studies in the genus Brachiaria using germplasm collected from wild African savannas in the 1980s revealed that most species and accessions within species are polyploid. Diploid, tetraploid, and pentaploid accessions have been found. We found asynchronous meiosis during microsporogenesis, followed by genome elimination, in two pentaploid (2n = 5x = 45) accessions (D53 and D71) of a hardy, invasive pasture grass, introduced from Africa to Brazil, Brachiaria decumbens. In these accessions, chromosomes paired as 18 bivalents and nine univalents during diakinesis, suggesting that these accessions resulted from a recent event of natural hybridization. The lack of chromosome associations in the genomes suggests that these accessions resulted from hybridization between two genotypes that are not closely related, with low genome affinity and with different meiotic rhythms. This supposition is reinforced by the meiotic behavior of the nine univalents, which were always laggard in relation to the other chromosomes and eliminated as micronuclei Genome elimination in Brachiaria decumbens in microspores. The behavior of these accessions, which have an odd level of ploidy and confirmed genome elimination, supports the general assumption that a polyploid accession can undergo a new event of polyploidization by natural hybridization (neopolyploidyzation). This evidence for natural hybridization in Brachiaria shows that this is a wild genus in an ongoing evolutionary process.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Genome elimination during microsporogenesis in two pentaploid accessions of Brachiaria decumbens (Poaceae)

Ricci¹,

Pagliarini²,

Valle³

2010

Genet. Mol. Res.

View full text Add to dashboard Cite

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“…Two nucleoli were also recently reported in hybrids of Brachiaria Boldrini et al, 2009Boldrini et al, , 2010. The genetic and functional consequences of uniting 2 divergent genetic systems into a common nucleus in only 1 parental cytoplasm can only be speculated at present (Wendel and Doyle, 2005). According to Liu et al (2001), the critical periods of this process are during and immediately after allopolyploidy formation, when the 2 distinct genomes are first brought into contact, thereby requiring a diverse array of accommodations.…”

Section: Meiotic Behavior and Evidence Of Recent Natural Hybridizationmentioning

confidence: 99%

Complete asynapsis resulting in 2n pollen formation in Paspalum jesuiticum Parodi (Poaceae)

Filho¹,

Santos²,

Souza³

et al. 2014

Genet. Mol. Res.

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ABSTRACT. Cytological investigation revealed complete asynapsis during microsporogenesis in 2 wild accessions of Paspalum jesuiticum collected in distinct Brazilian regions. Both accessions were hexaploid (2n = 6x = 60) and 60 univalents could be counted at diakinesis. In this phase, the majority of meiocytes exhibited univalents with both chromatids. After alignment at the metaphase plate, the chromatids segregated to the poles. Only 1 meiotic division (equational) occurred, and after cytokinesis, a dyad with 2n microspores was formed. The genetic constitution of the 2n gametes was equivalent to that of first division restitution (FDR). Since recombination did not occur, 100% transmission of parental heterozygosity could be expected from the FDR 2n gametes. The meiotic behavior of both accessions suggested that they resulted from a recent natural hybridization event. The potential use of the 2n gametes in Paspalum breeding programs has been discussed.

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“…Many studies have demonstrated that genetic and epigenetic changes, triggered by hybridization and whole genome duplication, play major roles in phenotypic expression [13][14][15][16], which in turn determines the fitness of newly formed polyploids [17]. Several important crops such as wheat, cotton and canola are allopolyploid and contain two or more different genomes [10,18].…”

Section: Phenotypic Variation and Hybrid Vigor In Polyploidsmentioning

confidence: 99%

Polyploidization and epigenetics

Gao

et al. 2011

Chin. Sci. Bull.

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The occurrence of polyploidy, or whole genome duplication, can result in instantaneous speciation. Because new polyploids are immediately reproductively isolated from their non-polyploid congeners, polyploidization has played an important role in the diversification of flowering plants and some vertebrates. Newly formed polyploids must respond to this instantaneous genomic change, which resembles "genome shock" syndrome to survive and reproduce successfully. Epigenetic changes, which do not cause changes to the sequence of DNA, can significantly contribute to the survival of and ultimately to the evolutionary success of new polyploids. Epigenetic regulation, both transcriptional and post-transcriptional, entails changes in DNA methylation, gene status and/or nucleolus dominance. These changes provide effective and flexible ways for a new polyploid to respond quickly to the enormous change in genetic material, to survive and potentially reproduce. We examine and assess certain epigenetic phenomena and possible pathways that may facilitate the evolutionary success of polyploid organisms.

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Polyploidy and evolution in plants.

Cited by 91 publications

References 0 publications

Genome elimination during microsporogenesis in two pentaploid accessions of Brachiaria decumbens (Poaceae)

Genome elimination during microsporogenesis in two pentaploid accessions of Brachiaria decumbens (Poaceae)

Complete asynapsis resulting in 2n pollen formation in Paspalum jesuiticum Parodi (Poaceae)

Polyploidization and epigenetics

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