MODULATION OF CULTURE MEDIUM ON THE EX SITU CONSERVATION OF Neoregelia mucugensis Leme (BROMELIACEAE)1

Abstract

Bromeliads are the target of predatory extractivism and consequently many species are included in the red list of threatened species, such as those belonging to the genus Neoregelia. Although Neoregelia mucugensis has not been evaluated for the degree of threat, its exploitation is exclusively extractive and its occurrence in Chapada Diamantina-BA is subject to the action of fires that affect the region annually. In this context, applying techniques aimed at protecting this genetic resource is fundamental for both the maintenance of its natural populations and the ex situ conservation of this genetic material. Plant tissue culture techniques have been successfully applied for the conservation of several bromeliad species. One of the methods used is slow growth, which consists in reducing plant metabolism and consequently decelerating its growth, which allows the maintenance of in vitro plant collections without the need for subculture. In this context, the objective of this study was to test the reduction of salts in the culture medium and the addition of osmoregulators on the induction of slow growth of N. mucugensis. Plants were subjected to treatments composed of different concentrations of MS medium and mannitol for a period of 12 months, when then analyses were conducted to evaluate growth, chlorophyll content and regeneration capacity of shoots in vitro. It was found that the treatment containing MS ½ and 7.8 g.L-1 of mannitol is indicated for in vitro conservation of N. mucugensis with maintenance of the regenerative capacity of its tissues.

Adequação das condições de crescimento mínimo para a conservação in vitro de Vernonia condensata

“…Ainda para os autores supracitados, a redução das concentrações de sais do meio básico de cultivo é outra estratégia amplamente empregada para a conservação sob regime de crescimento mínimo. Porém, no estabelecimento in vitro de um banco de germoplasma da espécie Pfaffia glomerata (Spreng) Pederson, Lima et al (2021) observaram que a redução de 50% dos sais do meio de cultura MS foi a mais indicada para conservação in vitro de N. mucugensis, por ter promovido menor crescimento das plantas, além do alto índice de sobrevivência.…”

“…A partir de mudanças no ambiente de cultivo, como redução da temperatura e da intensidade luminosa, redução na concentração de sais e nutrientes no meio de cultura, adição de inibidores de crescimento e agentes osmóticos, é possível desacelerar ou suprimir totalmente o crescimento de células, tecidos e órgãos (Lima et al, 2021;J. Sá et al, 2021).…”

Germinación asimbiótica, conservación ex situ e in vitro regeneración de plantas de Catasetum integerrimum Hook

“…One of the methods used is slow growth, which reduces plant metabolism and consequently decelerates its development, which allows the maintenance of in vitro plant collections without the need for subculture (Chauhan et al, 2019;Santos Lima et al, 2021;Petrova et al, 2021). The slow growth procedure is called medium-term conservation or minimal growth storage (Muñoz et al, 2019).…”