ABSTRACT. Tissue culture techniques have been employed for bromeliad mass propagation by means of the morphogenetic route of nodular cluster cultures (NCs). This study aimed to assess protein, carbohydrate and global DNA methylation (GDM) level dynamics during NCs induction from Vriesea reitzii seeds. Seeds were inoculated into Murashige and Skoog (MS) liquid medium supplemented with 4 µM α-naphthaleneacetic acid (NAA) to induce NCs and in culture medium without plant growth regulators to form normal seedlings. Samples collected at 0, 3, 7, 10, 14, and 21 days of culture were analyzed. All parameters assessed showed the same variation pattern. However, seeds inducing NCs showed significantly lower starch (6.0 mg g-1 FM), carbohydrate (10.7 mg g-1 FM) and GDM (11.0%) levels than seeds forming normal seedlings after 21 days in culture. On the other hand, the protein content (9.1 mg g-1 FM) was significantly higher during induction. NCs induction process through seeds is the result of gene reprogramming in the explant, which leads to morphological, biochemical and metabolic alterations. This involves dedifferentiation, high cell proliferation, high energy demand and protein synthesis, which is related to elevated metabolic activity.

O objetivo do trabalho foi caracterizar fisiologicamente a compatibilidade reprodutiva de sete cultivares de ameixeira-japonesa (Prunus salicina Lindl) por meio de hibridações, análise de frutificação efetiva e do crescimento de tubos polínicos (CTP). O frui set foi determinado 40 dias após as hibridações controladas, realizadas a campo. O grau de compatibilidade foi avaliado invivo, para determinar o CTP. A cv. América apresentou bom fruit set quando polinizada com as cvs. Rosa Mineira (26,7%), Amarelinha (8,7%) e Reubennel (12,7%). Os cruzamentos 'Gulf Blaze' x 'Gulf Rubi', 'Gulf Rubi' x 'Gulf Rubi' e 'Gulf Rubi' x 'Gulf Blaze' obtiveram um fruit set de 11,36%, 3,84% e 9,94%, respectivamente. Na polinização em laboratório, os tubos polínicos atingiram o óvulo ou ovário nesses cruzamentos, com exceção da autopolinização da 'Gulf Rubi'. No campo, não houve frutificação efetiva na autopolinização da 'América' e 'Gulf Blaze' e no cruzamento da 'América' x 'Pluma 7'. Os tubos polínicos nesses cruzamentos não chegaram a atingir o óvulo, com exceção da autopolinização da 'Gulf Blaze'. Concluiu-se que apenas os cruzamentos entre 'América' x 'Pluma 7' são incompatíveis, e a cultivar América é autoincompatível.

The objective of this study was to physiologically characterize the reproductive compatibility of seven Japanese plum cultivars (Prunus salicina Lindl) through hybridization, fruit set and pollen tube growth (PTG) analysis. The fruit set was determined 40 days after the controlled hybridization and was carried out under field conditions. The degree of compatibility was evaluated in vivo, to determine the PTG. The cv. América had good fruit set when pollinated with cvs. Rosa Mineira (26.7%), Amarelinha (8.7%) and Reubennel (12.7%). The crosses between 'Gulf Blaze' x 'Gulf Rubi', 'Gulf Rubi x Gulf Rubi' and 'Gulf Rubi x Gulf Blaze' had fruit set of 11.36%, 3.84% and 9.94% respectively. In the laboratory tests PTG reached the egg or the ovary in all these crosses, with the exception of self-pollination of 'Gulf Rubi'. In the field, no fruit set in self-pollination of 'América' and 'Gulf Blaze' and the cross between 'América x Pluma 7' was observed. The PTG in these crosses did not reach the egg, with the exception of self-pollination of 'Gulf Blaze'. It was concluded, that only the cross between 'América' x 'Pluma 7' is incompatible, and America is a self-incompatible cultivar.