Viabilidade polínica como seleção assistida no programa de melhoramento genético de triticale

Zanotto, Maira; Brammer, Sandra Patussi; Nascimento, A. do; Scagliusi, S. M. M.

doi:10.1590/s1413-70542009000700064

Cited by 13 publications

(10 citation statements)

References 5 publications

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“…This occurs because some meiotic abnormalities only have an effect during the germination stage and do not influence pollen viability (Junqueira Filho et al, 2003). Similar results have been reported for other genotypes of hexaploid triticale (Rosa et al, 2006;Zanotto et al, 2009).…”

Section: Meiotic Index and Pollen Viabilitysupporting

confidence: 90%

Backcrossing to increase meiotic stability in triticale

et al. 2015

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ABSTRACT. Triticale (X Triticosecale Wittmack) is an intergeneric hybrid derived from a cross between wheat and rye. As a newly created allopolyploid, the plant shows instabilities during the meiotic process, which may result in the loss of fertility. This genomic instability has hindered the success of triticale-breeding programs. Therefore, strategies should be developed to obtain stable triticale lines for use in breeding. In some species, backcrossing has been effective in increasing the meiotic stability of lineages. To assess whether backcrossing has the same effect in triticale, indices of meiotic abnormalities, meiotic index, and pollen viability were determined in genotypes from multiple generations of triticale (P 1 , P 2 , F 1 , F 2 , BC 1a , and BC 1b ). All analyzed genotypes exhibited instability during (2015) meiosis, and their meiotic index values were all lower than normal. However, the backcrosses BC 1a and BC 1b showed the lowest mean meiotic abnormalities and the highest meiotic indices, demonstrating higher stability. All genotypes showed a high rate of pollen viability, with the backcrosses BC 1a and BC 1b again exhibiting the best values. Statistical analyses confirmed that backcrossing positively affects the meiotic stability of triticale. Our results show that backcrossing should be considered by breeders aiming to obtain triticale lines with improved genomic stability.

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Section: Meiotic Index and Pollen Viabilitysupporting

confidence: 90%

Backcrossing to increase meiotic stability in triticale

et al. 2015

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“…However, in virtue of being practical and fast, they can rapidly generate additional information that may orientate breeders in their choice of genitors, in works involving controlled pollinations. Acetocarmine and propionic carmine are the most used dyes to determine pollen viability, also in routine analyses (Zanotto et al, 2009). In another study using two hybrids between B. ruziziensis and B. brizantha, these same authors observed less than 35% of viable pollen grains, as well as meiotic abnormalities such as irregular chromosome segregation, chromosome adherence and abnormal cytokinesis, which probably affected the viability of the pollen (Risso-Pascotto et al, 2005a).…”

Section: Resultsmentioning

confidence: 99%

Obtaining tetraploid plants of ruzigrass (Brachiaria ruziziensis)

et al. 2014

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-The objective of the present work was to induce chromosome doubling in genotypes of Brachiaria ruziziensis with potential for production of good-quality biomass and tolerance/resistance to stress caused by aluminum and spittlebugs. Germinated seeds of B. ruziziensis were immersed in 0.1% colchicine solution for 2 or 3 hours. Ploidy level was determined by flow cytometry and confirmed by chromosome count. Fertility of the tetraploid plants was assessed through evaluation of pollen viability by staining. There was no statistical difference with regard to seedling survival and number of duplicate seedlings between the treatments. Survival rate was 8%, of which 11.45% were tetraploid genotypes. The mean viability of pollen grains from the evaluated tetraploid plants ranged from 51.75 to 55.50%. So, the tetraploids plants obtained from genotypes of a bred population of ruzigrass produce fertile pollen, in percentages that render crosses viable in genetic breeding programs.

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“…Studies using acetocarmine 1% in 52 genotypes of Triticale, an intergeneric hybrid originated from crossing between tetraploid wheat and diploid rye, showed that the average percentage of viable pollen grains in the genotypes ranged from 68.6% to 98.8%. These values are considered high among genetically distinct genotypes (ZANOTTO et al, 2009). Acetocarmine 1% and propionic carmine 1% are widely used in routine analysis; however, they may be inadequate for some species, as thick exine of pollen grains can hamper dye penetration.…”

Section: Resultsmentioning

confidence: 99%

Morphology and pollen viability of Lolium multiflorum Lam.

et al. 2012

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Study and characterization of pollen grains are essential for different areas, especially taxonomy, genetic improvement, phylogeny, and paleobotany. As yet, there are no reports on pollen morphology of genotypes of naturalized Lolium multiflorum Lam., introduced cultivars or breeding populations, diploid or polyploid. Ten genotypes of annual ryegrass (L. multiflorum) were evaluated for the viability of pollen grains using propionic carmine and Alexander's stains, while morphology was assessed by the acetolysis technique. Measures of polar axis (P), equatorial diameter (E), exine thickness, and analysis of pollen grains were obtained by scanning electron microscopy (SEM). All genotypes showed high rate of pollen viability (> 89%) for both stains. There were differences between genotypes in the following quantitative traits: polar axis, equatorial diameter, exine, endexine, ektexine, and P/E ratio. Pollen grains were characterized as small, monoporates, with circular and non-prominent apertures. In addition to helping distinction of pollen grains, morphometric differences can be used later to compare ploidy levels, thus assisting in breeding programs of the species.Index terms: Scanning electron microscopy, ryegrass, acetolysis. RESUMOO estudo e a caracterização do grão de pólen são fundamentais para diferentes áreas, em especial, para a taxonomia, o melhoramento genético, a filogenia e a paleobotânica. Para genótipos de Lolium multiflorum Lam., naturalizados no Brasil, cultivares introduzidas ou populações de melhoramento, diploides e poliploides, não existem relatos sobre a caracterização morfopolínica. Nesse trabalho foram analisados dez gentótipos de azevém anual (L. multiflorum). A viabilidade dos grãos de pólen foi verificada por coloração com os corantes carmim propiônico e Alexander e a morfologia por meio da técnica de acetólise, sendo obtidas medidas do eixo polar (P), do diâmetro equatorial (E), e da espessura da exina, e análise dos grãos de pólen por microscopia eletrônica de varredura (MEV). Todos os genótipos avaliados apresentaram alta taxa de viabilidade polínica (>89%) para os dois corantes utilizados. Houve diferença entre os genótipos para os caracteres quantitativos eixo polar, diâmetro equatorial na vista equatorial, exina, endoexina, ectoexina e razão P/E. Os grãos de pólen foram caracterizados como pequenos, monoaperturados, com abertura não proeminente e com âmbito circular. As diferenças morfométricas entre os grãos-de-pólen podem auxiliar na distinção entre os mesmos e, posteriormente, serem utilizadas para comparação entre os níveis de ploidia, auxiliando, assim, nos programas de melhoramento da espécie.Termos para indexação: Microscopia de varredura, azevém, acetólise.

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Viabilidade polínica como seleção assistida no programa de melhoramento genético de triticale

Cited by 13 publications

References 5 publications

Backcrossing to increase meiotic stability in triticale

Backcrossing to increase meiotic stability in triticale

Obtaining tetraploid plants of ruzigrass (Brachiaria ruziziensis)

Morphology and pollen viability of Lolium multiflorum Lam.

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