Relationship between pollen morphology and chromosome numbers in Brazilian species of Lippia L. (Verbenaceae)

Sousa, Saulo Marçal de; Pierre, Patrícia Maria Oliveira; Torres, Giovana Augusta; Davide, Lisete Chamma; Viccini, Lyderson Facio

doi:10.1590/s0001-37652013005000010

Cited by 14 publications

(8 citation statements)

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“…The cytotype of Lippia alba with 30 chromosomes described as a diploid by Bose and Choudhury (1960) may itself have a polyploid origin and could in fact be a diploid‐like cytotype, which originated by ancient whole genome duplication events, later acquiring disomic behavior. This hypothesis is supported by different authors who hypothesized the basic chromosome number for Lippia as x = 5 (Sanders, 2001; Viccini et al, 2006; Campos et al, 2011; Sousa et al, 2012, 2013) and reinforce the view that polyploidy has played an important role in the evolution of the genus. The fact that we have found a 2 n = 38 cytotype, intermediate between a 2 n = 30 diploid and a 2 n = 45 triploid, that produces some viable pollen is suggestive of a chromosomal base number of below n = 15.…”

Section: Discussionsupporting

confidence: 55%

“…Seven sections are recognized in the genus Lippia (Troncoso, 1974), with section Zapania being the most complex. Considering the data available so far, this section has both the lowest and the highest chromosome number and DNA content recorded (2 n = 20 from L. rubella and 2 n = 56 from L. rotundifolia and L. lacunosa ) including at least three species with high chromosome numbers suggestive of polyploidy: L. lacunosa (2 n = 56), L. rotundifolia (2 n = 56) and L. diamantinensis (2 n = 52) (Viccini et al, 2006; Campos et al, 2011; Sousa et al, 2012, 2013). Lippia alba (Mill.)…”

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confidence: 97%

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Lippia alba(Verbenaceae): A new tropical autopolyploid complex?

Reis

Sousa

Vale

et al. 2014

American J of Botany

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• Premise of the study: Tropical regions have high species diversity, and polyploidization is a major mechanism of speciation in plants. However, few cases of natural polyploidy have been reported in tropical regions. Lippia alba, is a tropical, aromatic shrub with a wide distribution, extensive morphological plasticity, and several chemotypes. The species has long been recognized as a diploid with 2n = 30 chromosomes. Recently, two variations in chromosome number (2n = 60; 2n = 12-60) have been reported, suggesting the occurrence of polyploidy within the species.• Methods: Flow cytometry was used to investigate the genome size in 106 accessions from 14 Brazilian States. Conventional and molecular cytogenetic techniques and pollen viability analysis were employed to characterize each chromosome number observed.• Key results: The DNA 1C-value varied from 1.17 to 3.45 pg, showing a large variation in genome size. Five distinct chromosome numbers were observed (2n = 30, 38, 45, 60, 90); three are cytogenetically described here for the first time. The 5S rDNA signals varied proportionally according to each chromosome number, but 45S rDNA sites did not. High rates of meiotic irregularity were observed, mainly in cytotypes with higher chromosome numbers.• Conclusions: The data provide new support for the occurrence of a polyploid series in Lippia alba. We provide a hypothesis for how this complex may have arisen. Other cryptic polyploid complexes may remain undiscovered in tropical regions.

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Section: Discussionsupporting

confidence: 55%

mentioning

confidence: 97%

Lippia alba(Verbenaceae): A new tropical autopolyploid complex?

Reis

Sousa

Vale

et al. 2014

American J of Botany

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“…O tamanho do grão de pólen em várias espécies tem relação com o nível de ploidia (Raseira & Raseira, 1996). A relação positiva entre o nível de ploidia e tamanho do pólen tem sido relatada para vários gêneros de plantas poliploides, como Avena L. (Katsiotis & Forsberg, 1995), Mentha L. (Celenk et al 2008) e Lippia L. (Sousa et al 2013). Conforme Simioni et al (2004) plantas que produzem grãos de pólen com 30% a 40% de incremento no tamanho, quando comparados com grãos considerados normais, servem como um indicativo de grãos de pólen não reduzidos.…”

Section: Acessosunclassified

Estimativa da viabilidade polínica de araçazeiro (Psidium cattleianum Sabine) através de distintos métodos de coloração

Hister

Tedesco

2016

Rev. bras. plantas med.

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RESUMO:A análise histoquímica dos grãos de pólen através do uso de corantes permite a determinação de sua viabilidade polínica. O objetivo deste estudo foi comparar a eficiência dos corantes orceína acética 2% e reativo de Alexander modificado, para estimar a viabilidade polínica de vinte acessos de araçazeiro (Psidium cattleianum Sabine) -uma árvore de frutos muito apreciados que também é utilizada para fins medicinais. Botões florais na pré-antese foram coletados e fixados em etanol:ácido acético (3:1) por 24 horas, após os botões foram transferidos para etanol 70% e mantidos sob refrigeração. A técnica de esmagamento das anteras foi utilizada no preparo das lâminas. Para cada acesso foram preparadas 2 lâminas por corante e analisados 500 grãos de pólen por lâmina. A viabilidade polínica foi estimada através da porcentagem de grãos de pólen viáveis. De modo geral, observou-se que os grãos de pólen corados com orceína acética 2% apresentaram viabilidade alta, acima de 98,1%, e os acessos não diferiram entre si. A viabilidade polínica através da coloração com a solução de Alexander variou de 43% (acesso Silveira Martins 1) a 97% (acesso Candelária 1), mostrando que provavelmente exista variabilidade genética entre os acessos. Em apenas dois acessos não houve diferença significativa entre os valores de viabilidade encontrados através dos dois corantes testados. Conclui-se então que a orceína acética 2% superestimou a viabilidade polínica de P. cattleianum e que o reativo de Alexander é o mais preciso, devido a sua dupla coloração (verde de malaquita + fucsina ácida). Assim, indica-se o reativo de Alexander para análise de estimativa da viabilidade polínica de genótipos de araçá envolvidos em um programa de melhoramento genético. Palavras-chave:Araçá, orceína acética, reativo de Alexander, viabilidade polínica ABSTRACT: Estimation of pollen viability of strawberry guava (Psidium cattleianum Sabine) through distinct staining methods. The histochemical analysis of pollen grains through the use of stains makes it possible to determine their pollen viability. The purpose of this study was to compare the efficiency of 2% acetic orcein and Alexander's stain modified, in estimating the pollen viability of twenty strawberry guava accessions (Psidium cattleianum Sabine) -a valued fruit tree which is used for medicinal purposes. Pre-anthesis flower buds were collected and fixed in ethanol:acetic acid (3:1 v/v) for 24 hours at room temperature, subsequently they were stored in 70% ethanol under refrigeration. The anther squash technique was performed for slide preparation. In each accession two slides per stain and 500 pollen grains were analyzed. The pollen viability was estimated according to the percentage of viable pollen grains. Overall, it was observed that pollen grains stained with 2% acetic orcein evinced a high viability, higher than 98,1%, and the accessions did not differ. The pollen viability estimated with Alexander's stain varied from 43% (accession of Silveira Martins 1) to 97% (accession of Candelária 1), in...

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“…Katisiotis and Forsberg (Mabberly, 1987;Ohri et al, 2004;Kundu and Schmidt, 2011, www.SL.ku. (2005) and Celenk et al (2008) have reported this positive relationship between ploidy level and pollen size for several plant genera in natural or artificially induced polyploids. Sousa et al (2013), however, found a positive association between the chromosome number and size of pollen grains and also between the length and width of the colpi in species of Lippia L. (Verbenaceae). Campos et al (2011) also observed a positive correlation between chromosome number and the DNA C-value for 28 species of Lippia L. (Verbenaceae).…”

Section: Discussionmentioning

confidence: 96%

Pollen heteromorphism in Schleichera Lour. (Sapindaceae), observed in surface soil samples from central India

Quamar¹,

Thakur²,

Singh³

et al. 2021

Acta Palaeobotanica

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Angiosperms display striking variation of pollen morphological features within and between populations of the same species, as well as within individual plants. We describe and illustrate variation of pollen aperture number, which is called pollen heteromorphism, in Schleichera Lour. (Sapindaceae) from surface soil samples collected from central India, based on combined observations from light microscopy (LM) and confocal laser scanning microscopy (CLSM). Tri-zono-parasyncolporoidate pollen grains are, in general, known to occur in Schleichera Lour., but occasional tetra-zono-parasyncolporoidate pollen is also recorded, for the first time, from Chhattisgarh State, central India. Changes in ploidy level (diploidy/polyploidy), chromosome number, the C-value of DNA, completion of meiosis, as well as environmental factors and/or pollination ecology could be driving the occurrence of pollen heteromorphism. The present study could provide insights into the phylogeny and systematics, and has implications for pollen preservation as well.

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Relationship between pollen morphology and chromosome numbers in Brazilian species of Lippia L. (Verbenaceae)

Cited by 14 publications

References 16 publications

Lippia alba(Verbenaceae): A new tropical autopolyploid complex?

Lippia alba(Verbenaceae): A new tropical autopolyploid complex?

Estimativa da viabilidade polínica de araçazeiro (Psidium cattleianum Sabine) através de distintos métodos de coloração

Pollen heteromorphism in Schleichera Lour. (Sapindaceae), observed in surface soil samples from central India

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