Genetic diversity in sexual diploid and apomictic tetraploid populations of Paspalum notatum situated in sympatry or allopatry

Daurelio, Lucas D.; Espinoza, Francisco; Quarín, Camilo Luis; Pessino, Silvina Claudia

doi:10.1007/s00606-003-0070-6

Cited by 61 publications

(70 citation statements)

References 20 publications

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“…If other wild diploids were identified, they could have been used to introduce novel variation in P. notatum, but, until now, no other diploids have been located outside the Argentinian region of P. notatum var. saurae (Pozzobon & Valls, 1997;Daurelio et al, 2004). The objective of the present work was to determine chromosome numbers, chromosome associations at diakinesis and metaphase I, and pollen viability in accessions of P. notatum which are part of a breeding project.…”

Section: Introductionmentioning

confidence: 98%

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Cytogenetic data for Paspalum notatum Flügge accessions

Dahmer

Schifino-Wittmann

Dall'Agnol

et al. 2008

Sci. agric. (Piracicaba, Braz.)

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Several species of the genus Paspalum L. are important forages, due to quality, productivity and tolerance to environmental stresses. Chromosome numbers, meiotic configurations and pollen fertility were evaluated in a collection of 85 accessions of Paspalum notatum Flügge and in seven accessions of Pensacola (P. notatum var saurae). All P. notatum accessions were tetraploid, with 2n = 4x = 40, except one diploid accession, considered as an escape of Pensacola. All Pensacola plants had 2n = 2x = 20. Meiotic configurations at diakinesis and metaphase I varied among tetraploid accessions, from plants with only bivalents to plants with high frequency of quadrivalents. Pollen fertility varied from 82.5 to 95.9% among diploid accessions and from 72.4 to 97.9% among the tetraploid. Due to the apomictic mode of reproduction of tetraploid P. notatum, meiotic irregularities can be maintained by the plants without harming their propagation. At the same time, pollen fertility should be high enough to assure endosperm development, since the species is pseudogamous. Wild diploid P. notatum populations, apart from the endemic P. notatum var saurae are very rare. From a plant breeding point of view, all the examined tetraploid accessions are potentially male-fertile and could be used as males in crosses. Key words: apomixis, chromosome numbers, meiotic configurations, plant breeding, pollen fertility DADOS CITOGENÉTICOS PARA ACESSOS DEPaspalum notatum FLÜGGE RESUMO: Muitas espécies do genus Paspalum L. são importantes forragens, devido à qualidade, produtividade e tolerância para o stress ambiental. Números cromossômicos, configurações meióticas e fertilidade do pólen foram analisados em uma coleção de 85 acessos de Paspalum notatum Flügge e sete acessos de Pensacola (P. notatum var saurae). Todos os acessos de P. notatum eram tetraplóides, com 2n = 4x = 40, com exceção de um diplóide, considerado como escape de Pensacola. Todas as plantas de Pensacola examinadas tinham 2n = 2x = 20. Foi verificada variação entre os acessos tetraplóides quanto às configurações cromossômicas em diacinese e metáfase I, desde plantas com apenas bivalentes até aquelas com alta freqüência de quadrivalentes. A fertilidade do pólen variou de 82,5 a 95,9% entre os acessos diplóides e de 72,4 a 97,9% entre os tetraplóides. Devido ao modo de reprodução apomítico de P. notatum tetraplóide, irregularidades meióticas podem ser mantidas sem prejuízo da propagação. Ao mesmo tempo, a fertilidade do pólen deve ser suficientemente alta para assegurar a formação do endosperma, já que a espécie é pseudogâmica. Diplóides silvestres de P. notatum, além do endêmico P. notatum var saurae são muito raros. Do ponto de vista do melhoramento, todos os tetraplóides são potencialmente macho-férteis e poderiam ser utilizados como genitores masculinos em cruzamentos. Palavras-chave: apomixia, números cromossômicos, configurações meióticas, melhoramento genético, fertilidade do pólen

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Section: Introductionmentioning

confidence: 98%

“…Moraes-Fernandes et al (1973) found only the tetraploid level among the 16 Brazilian (Rio Grande do Sul) and one introduced accession from P. notatum. Daurelio et al (2004) reported that despite a search in other regions of Argentina, the diploids are all botanically P. notatum var. saurae and restricted to Northeastern and Central-Eastern Argentina.…”

mentioning

confidence: 99%

Cytogenetic data for Paspalum notatum Flügge accessions

Dahmer

Schifino-Wittmann

Dall'Agnol

et al. 2008

Sci. agric. (Piracicaba, Braz.)

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“…In these conditions, native species of the genus Paspalum have advantages over the exotic species because of the greater adaptation and great intra-and interspecific variability in forage-related traits (Pereira et al, 2012;Daurelio et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Genetic gain in apomictic species of the genus Paspalum

et al. 2017

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1The objective of this work was to provide means to obtain genetic gain in apomictic species of the genus Paspalum by identifying traits that simultaneously show high correlation and heritability. Thus, to determine the amount of phenotypic variation due to genetic and environmental effects and the degree of association between leaf dry matter production and other traits of forage interest that are easy to select and measure will bring agility and economy in the selection of forage species. The experiment was conducted in the years 2009/10 and 2010/11 in the municipalities of Eldorado do Sul and Augusto Pestana, RS, Brazil, in a randomized complete block design with three replicates. The increase in the direct selection pressure on total and leaf dry matter of apomictic accesses of the genus Paspalum is enhanced by a greater contribution of genetic effects than environmental effects on the composition of the phenotypic variance. Efficient genetic gain in leaf production is achieved by indirect selection of total dry matter, which is a trait of high heritability and easy to select and measure.

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“…Ploidy levels reported include 2x, 3x, 4x, 5x, 6x, 7x, 8x, 10x, and 12x, and species consisting only of sexual-diploid cytotypes are relatively uncommon. Apparently, sexual-diploids are distributed in rather restricted areas, as well as certain hybrid combinations (Quarín and Lombardo, 1986;Urbani et al, 2002;Daurelio et al, 2004). Moreover, groups previously thought of as rather simple autopolyploid assemblages have turned out to be complex interspecific hybrid groups (Vaio et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

“…According to Bennett and Bashaw (1966), "every desirable characteristic of a forage plant can be found in some Paspalum species". A copious literature on the cytogenetics of Paspalum and its relationship to ploidy levels, reproductive systems, natural hybridization, genomic associations, and anatomical adaptations has accumulated during the last decades (Burson, 1983;Quarín, 1997, 1998;Daurelio et al, 2004;Machado et al, 2005; and references therein), regarding especially some polyploid hybrid complexes that include highly valuable forage species, as in the case of P. dilatatum Poir. Unfortunately, collections and data on genetics and reproduction from non-foraging species are far scarcer.…”

Section: Introductionmentioning

confidence: 99%

Unusual chromosome numbers in Paspalum L. (Poaceae: Paniceae) from Brazil

Peñaloza¹,

Côrtes²,

Pozzobon³

et al. 2008

Genet. Mol. Res.

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ABSTRACT. Somatic chromosome numbers were determined for 20 new germplasm accessions of Paspalum, belonging to 17 species collected in Brazil. Chromosome number is reported for the first time for P. reduncum (2n = 18), P. cinerascens (2n = 20), P. cordatum (2n = 20), P. filgueirasii (2n = 24), P. ammodes (2n = 36), P. bicilium (2n = 40), P. heterotrichon (2n = 40), and P. burmanii (2n = 48). New cytotypes were confirmed for two germplasm accessions of P. carinatum (2n = 30) and P. trachycoleon (2n = 36), one of P. clavuliferum (2n = 40) and one of P. lanciflorum (2n = 40), indicating variability in these species. The remaining chromosome numbers reported here confirm previous counts. The unexpected chromosome numbers 2n = 18, 24, 36, and 48 in Paspalum species, which are usually shown to be multiples of 10, suggest that much more collection and cytogenetic characterization are necessary to assess the whole chromosomal and genomic multiplicity present in the genus, which seems to be much more diverse than currently thought to be.

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Genetic diversity in sexual diploid and apomictic tetraploid populations of Paspalum notatum situated in sympatry or allopatry

Cited by 61 publications

References 20 publications

Cytogenetic data for Paspalum notatum Flügge accessions

Cytogenetic data for Paspalum notatum Flügge accessions

Genetic gain in apomictic species of the genus Paspalum

Unusual chromosome numbers in Paspalum L. (Poaceae: Paniceae) from Brazil

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