Maturação de sementes de Aechmea bromeliifolia (Rudge) Baker e Vriesea paraibica Wawra (Bromeliaceae)

Abstract

-(Seed maturation of Aechmea bromeliifolia and Vriesea paraibica (Bromeliaceae)). Studies on seed physiology can contribute to conservation and restoration of native vegetation, mainly for the ex situ conservation. Seed maturation is important to assist in the correct time for harvesting fruit, in order to obtain seeds with higher physiologic potential. Despite the ecological importance of many Bromeliaceae species, there is a lack of knowledge about their seeds. In this study the physical and physiological changes during fruit and seed ripening of Vriesea paraibica Wawra and Aechmea bromeliifolia (Rudge) Baker were analyzed. The flowers were tagged during anthesis and fruit harvest was carried out weekly or fortnightly, depending on the species, until the seeds were naturally dispersed. Water content and dry mass were measured by gravimetric method (103 ºC for 17 hours) and seed germination was performed in plastic box (gerbox) with paper filter at 25 °C under a photoperiod of 8 hours of light and 16 hours of darkness for 30 days. The results showed that Aechmea bromeliifolia seeds reached physiological maturity from 65 to 72 days after anthesis and for Vriesea paraibica, 285 days after anthesis. The external visual characteristics of fruits and seeds can be used as a tool to estimate fruit harvesting in order to reach the maximum seed physiological quality for the species. However, the decision for seed harvesting should be confirmed by water content and dry mass of V. paraibica and A. bromeliifolia seeds Key words: Bromeliad, germination, harvest point, physiological maturity RESUMO -(Maturação de sementes de Aechmea bromeliifolia (Rudge) Baker e Vriesea paraibica Wawra (Bromeliaceae)). O conhecimento sobre a fisiologia de sementes pode contribuir para a conservação e restauração da vegetação nativa, especialmente quanto à conservação ex situ. Dentre estes estudos, os de maturação são importantes para auxiliar no momento correto de coleta, permitindo a obtenção de sementes com elevado potencial fisiológico. Apesar da importância ecológica de muitas espécies de Bromeliaceae, pouco se conhece quanto às suas sementes. No presente estudo foram analisadas as modificações físicas e fisiológicas durante a maturação de frutos e sementes de Vriesea paraibica Wawra e Aechmea bromeliifolia (Rudge) Baker. As flores foram marcadas durante a antese e as coletas de frutos realizadas semanal ou quinzenalmente, dependo da espécie, até que as sementes fossem dispersas naturalmente. Foram determinados o teor de água e o conteúdo de massa seca, pelo método gravimétrico (103 ºC por 17 horas) e o teste de germinação das sementes foi conduzido em gerbox forrado com papel filtro a 25 ºC e fotoperíodo de 8 horas de claro por 16 horas de escuro, durante 30 dias. Os resultados permitiram concluir que as sementes de A. bromeliifolia atingiram a maturidade fisiológica em período próximo a 65-72 dias após a antese e as de V. paraibica aos 285 dias. O acompanhamento das modificações externas visuais de frutos e sementes pode auxil...

Maturation and Desiccation Tolerance in Seeds of Sesbania virgata (Cav.) Pers.

“…In Erythrina speciosa seeds, Molizane et al (2013) observed pronounced spaces in the osteosclereid region and parenchyma cells during final stages of maturation, due to the drastic drop in water content, which was also observed for S. virgata seeds in the present study, observing that during desiccation, the cells reduce their size due to water loss and the intercellular spaces become visible between the osteosclereids In the absence of drying, there was an increase in germination values as the seeds advanced throughout the developmental stages until their maximum at 85 DAA. (Figure 5).…”

Germination and survival of Aechmea gamosepala on different substrates

“…The prospect of new ornamental plants from native species expands the product offering to the market of flowers (Tognon et al, 2016), in this context stands out the bromeliads, which annually have dozens of new species inserted in the ornamental plant trade (Pulido et al, 2018;Negrelle and Anacleto, 2019).…”

“…The use of bromeliads as ornamental plants was intensified in Brazil after the seventies with the introduction of this group of plants in landscaping projects, finding great acceptance among the population and also among architects and landscapers (Negrelle and Anacleto, 2019).…”

“…The extraction of bromeliads for commercial purposes is also registered in the States of Rio de Janeiro, Bahia, Espirito Santo and Santa Catarina, however Parana is the region where this practice had greater adherence, especially among the vulnerable and impoverished communities who saw in the facilitated extraction the possibility of obtaining income (Negrelle and Anacleto, 2019).…”

Germination of spineless Bromelia laciniosa Mart. ex Schult (Bromeliaceae) seeds subjected to chemical scarification

“…SCIENTIFIC NOTES / NOTAS CIENTÍFICAS et al, 2010). Other problems pointed out for these plants are the long flowering period and the lack of uniformity in the fruit maturation process (Molizane et al, 2013), increasing the need for research on the ideal harvesting point, which for many species is based on fruit color.…”