Resumo

FRANCO-MORA, Omar  e  TANABE, Kenji. Polyamine content in anthers and during pollen germination in Pyrus pyrifolia Nakai. Agrociencia [online]. 2008, vol.42, n.5, pp.529-536. ISSN 2521-9766.

In two production cycles, 2003 and 2004, the polyamine content in anthers of Japanese pear (Pyrus pyrifolia Nakai), cvs. Niitaka, Housui and Choujuurou, was determined through the technique of high performance liquid chromatography, 3, 2, 1 and 0 d before anthesis (DBA). In the three cultivars, the putrescine content decreased from between 9.8 and 11.2, to 4.2 and 5.6 µmol g^-1 humid biomass (HB), when passing from 3 to 2 DBA. The spermidine content was higher (p<0.05) in Housui and Choujuurou than in Niitaka at 3 DBA and at day of onset of anthesis (DOA), but not at 2 and 1 DBA. The spermidine contents values were lower than 1 µmol g^-1 HB in Niitaka, whereas in Housui and Choujuurou they doubled from 4 to 8 and 3 to 6 µmol g^-1 HB, from 3 DBA to DOA. The reduction in putrescine suggests that there was synthesis of spermidine and spermine in the maturation of the pollen producing anthers. During the germination of pollen in both androfertile cvs., Housui and Choujuurou, at 0, 0.5, 1.5, 2, 3, 4, 6 and 8 h, an approximate germination of 90% was reached in 4 h. In this germination, putrescine decreased significantly (p<0.05) in the first 30 min and the spermidine in 4 h, in both cultivars. In contrast, the spermine increased significantly at 30 min and at 3 h, which suggests its biosynthesis during the germination of the pollen.

Palavras-chave : Pyrus pyrifolia; spermidine; spermine; germination of pollen; putrescine; pollen tube.

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