Morphology and viability of castor bean genotypes pollen grains/Morfologia e viabilidade de graos de polen de genotipos de mamoneira

• Published in: Acta scientiarum. Agronomy 2016-01, p.77
• Main Authors: Diamantino, Maria Selma Alves Silva, de Carvalho Costa, Maria Angelica Pereira, Soares, Taliane Leila, Morais, Daniel Vieira, Silva, Simone Alves, de Souza, Everton Hilo
• Format: Article
• Language: Spanish
• ISSN: 1679-9275

The objective of this work was to characterize the morphology and viability of the pollen of 15 genotypes of castor bean (Ricinus communis L.) and to generate information that can assist in the selection of highly promising male parents for future use in genetic improvement programs aimed at producing seeds for oil extraction. Acetolysis and scanning electron microscopy was used to characterize the morphology of the pollen. The viability of the pollen grains was estimated by in vitro germination and colorimetric analysis (acetocarmine 2% and 2, 3, 5-triphenyltetrazolium chloride 1%). For the in vitro germination, pollen grains were grown in 10 types of solidified culture medium consisting of different concentrations of sucrose, boric acid, calcium nitrate, magnesium sulfate and potassium nitrate. The pollen grains had the following characteristics: medium size, isopolar and subspheroidal shape, radial symmetry, circular ambit, 3-colporate, elongated endoapertures, tectate exine and granulated sexine. The acetocarmine dye overestimated pollen viability. The media M5 and M8 were the most efficient at promoting the germination of pollen grains. The studied genotypes had high levels of viability and can therefore be used as male parents in genetic improvement programs. Keywords: Ricinus communis L., in vitro germination, colorimetric analysis, pollen tube. O objetivo deste trabalho foi caracterizar a morfologia e a viabilidade polinica em quinze genotipos de mamoneira (Ricinus communis L.), a fim de gerar informacoes que possam auxiliar a selecao de genitores masculinos altamente promissores para posterior utilizacao em programas de melhoramento, tendo em vista a producao de sementes para a extracao de oleos. As descricoes morfopolinicas foram feitas a partir da acetolise e microscopia eletronica de varredura. A viabilidade dos graos de polen foi estimada por meio da germinacao in vitro e analise colorimetrica (carmim acetico 2% e 2, 3, 5-cloreto de trifeniltetrazolio 1%). Para a germinacao in vitro, graos de polen foram inoculados em dez tipos de meio de cultura, constituidos de diferentes concentracoes de sacarose, acido borico, nitrato de calcio, sulfato de magnesio e nitrato de potassio e solidificado. Os genotipos apresentam grao de polen de tamanho medio, isopolares, subesferoidal, simetria radial, ambito circular, 3-colporados, endoaberturas lalongadas, exina tectada e sexina granulada. O corante carmim acetico superestima a viabilidade de polen. Os mei