RESUMO -O presente trabalho teve por objetivo a avaliação da perda da tolerância à dessecação (TD) em sementes de peltophorum dubium durante e após a germinação. As sementes foram colocadas para germinar e, ao atingirem 1, 3 e 5 mm de raiz primária (68% de umidade), foram desidratadas em sílica gel, até atingirem o grau de umidade inicial (8%), sendo em seguida reidratadas e avaliadas quanto à sobrevivência (retomada do crescimento e formação de plântulas normais). Procedimento semelhante foi adotado para os ensaios realizados durante a embebição, onde foram amostradas 100 sementes divididas em quatro repetições de 25 para cada um dos seguintes tempos de embebição: 12, 24, 48, 60 e 72 horas. Em seguida, foram selecionados diferentes pontos de interesse (12, 48 e 60 horas de embebição e raízes primárias com 1 mm de comprimento) para determinação da quantidade de DNA nuclear, afim de analisar possível correlação entre início do ciclo celular e perda da TD. Com relação ao comportamento de sementes germinadas submetidas à secagem e reidratação, para os três comprimentos de raízes primárias amostradas, não houve sobrevivência. Foi observada queda progressiva na sobrevivência de sementes de peltophorum dubium relacionada ao tempo de embebição, e posterior secagem e reidratação, sugerindo que a perda da TD desta espécie acontece nos estágios iniciais da germinação, antes da protrusão da radícula. Sementes embebidas por 12 h, 24 h, 48 h, 60 h, 72 h e aquelas germinadas, com 1 mm de comprimento radicular, apresentaram índices iguais a 98%, 93%, 83%, 35%, 17% e 0% de sobrevivência respectivamente. Os estudos relacionados ao conteúdo de DNA nuclear não demonstram correlação entre retomada do ciclo celular e perda da TD.Termos para indexação: DNA nuclear, ciclo celular, peltophorum dubium. EVALUATION OF THE LOSS OF DESICCATION TOLERANCE AND NUCLEAR DNA CONTENT IN SEEDS OF peltophorum dubium (SPRENG.) TAUBERT DURING AND AFTER GERMINATIONABSTRACT -The objective of this study was to investigate the loss of desiccation tolerance (DT) in seeds of peltophorum dubium (Sprengel) Taubert, during and after germination. p. dubium seeds were sown, removed after germination when the primary root lengths reached 1, 3 and 5 mm
The aim of this study was to evaluate DNA integrity and to identify ultrastructural changes in the primary root of Peltophorum dubium seeds subjected to drying, since these changes may reflect the germination capacity. Seeds were germinated and were dehydrated when reached 1 mm in length of the primary root, until reaching different moisture contents, being then rehydrated and evaluated in relation to survival. After this procedure, different points of interest (control, 20% and 10% moisture content) were selected to evaluate DNA and cell ultrastructure integrity in order to detect possible cellular changes in primary roots after dehydration. When dried down to 32% moisture, there was no influence on the growth resumption of the germinated seeds, but when they were dehydrated to 20% moisture, the survival was reduced to 67%, reaching nullity in the survival with drying to 8% moisture. By the evaluation of ultrastructural changes in root cells, it was observed that drying to approximately 20% moisture content marked the onset of damages by desiccation, both physiologically and ultrastructurally. Drying to levels close to 10% moisture content was not only responsible for total disorganization and rupture of membranes, but also promoted intracellular collapse. Loss of genomic DNA integrity was observed during drying.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.