Conservation of Vriesea flammea L.B.Sm., an endemic Brazilian bromeliad: effects of nutrients and carbon source on plant development

Abstract

<jats:p>Abstract Bromeliaceae is restricted to the Neotropical region and has a high degree of endemism, which contributes to increased biodiversity because of the diverse morphological characteristics of individuals. In order to develop an in vitro conservation technology to obtain plants for reintroduction, seeds of Vriesea flammea L.B.Sm. were collected, sterilized and germinated in culture medium. The plants obtained were cultured for 180 days in MS medium with different concentrations of mineral nutrients (25 and 50% of nitrogenous salts and macronutrients), and different concentrations of sucrose (20, 30, 40, 50 and 60 g L-1), and then acclimatized for 150 days on commercial substrate. When seeds were sterilized directly, only 4% of them were contaminated, whereas sterilization of capsules resulted in 43.6% contaminated seeds. Germination rates above 80% were recorded. Low concentrations of nitrogenous salts and macronutrients produced greater than 76% survival and promoted greater in vitro plant development than the complete MS medium. The development of the aerial system, root system, fresh mass and photosynthetic pigments were positively related to sucrose concentration in vitro. The highest sucrose concentration also indirectly promoted greater development of the aerial system and fresh mass of acclimatized plants. We established conditions for in vitro cultivation and acclimatization for efficient propagation of V. flammea with a view towards conservation of the species or reestablishment of natural populations.</jats:p>

Morphological, physiological features and differences of Vriesea splendens ’Fire’ plants during in vitro multiplication and rooting

“…The supplementation of certain accessories (such as B5 vitamins) increased shoot proliferation and fresh weight of V. scalaris, specimens with larger number shoots also had larger weight (Da Silva et al, 2009). In case of V. flammea, higher sucrose concentrations (up to 60 g l -1 ) promoted larger fresh mass (Sasamori et al, 2020).…”

“…In case of Vrieseas, mainly endangered, endemic Brazilian species used for in vitro studies in order to lowering pressures on their natural, treated populations (Tamaki et al 2011). As induction phase, mostly sterilized seeds of V. cacuminis (Resende at al., 2016), V. scalaris (Da Silva et al, 2009); V. gigantea and V. philippocoburgii (Droste et al, 2005); V. heliconioides (Hernández-Meneses et al, 2018); V. flammea (Sasamori et al, 2020) were placed on total or half-strength Murashige & Skoog (1962) MS or Knudson (1946 K medium. Besides seeds, capsules also disinfected, but this method resulted higher contamination (Sasamori et al, 2020).…”

“…As induction phase, mostly sterilized seeds of V. cacuminis (Resende at al., 2016), V. scalaris (Da Silva et al, 2009); V. gigantea and V. philippocoburgii (Droste et al, 2005); V. heliconioides (Hernández-Meneses et al, 2018); V. flammea (Sasamori et al, 2020) were placed on total or half-strength Murashige & Skoog (1962) MS or Knudson (1946 K medium. Besides seeds, capsules also disinfected, but this method resulted higher contamination (Sasamori et al, 2020). In certain cases, young or basal leaves successfully used as explants in order to establish in vitro nodular cultures of V. reitzii (Alves et al, 2006;Dal Vesco & Guerra, 2010) and V. scalaris (Da Silva et al, 2009).…”

“…In the next steps, plant growth regulators such as BAP, GA3, NAA, IBA (Resende et al, 2016;Hernández-Meneses et al, 2018), KIN (Da Silva et al, 2009), 2-iP, 2,4-D (Alves et al, 2006;Dal Vesco & Guerra, 2010) or other accessories like activated charcoal (Droste et al, 2005), ascorbic acid, hydrolysed casein, B5 vitamins (Da Silva et al, 2009 were added so as to stimulate multiplication and rooting. Not only hormones but also the effect of different concentrations of sucrose was examined during in vitro development and acclimatization of V. inflata (Freitas et al, 2015) and V. flammea (Sasamori et al, 2020). However, Vrieseas have slow growth (as usual in case of the other bromeliads, moderate development is typical), their acclimatization was not difficult, especially when in vitro plantlets were cultured previously on media with GA3 (Resende et al, 2016;Hernández-Meneses et al, 2018) or lower values of MS macronutrients (Sasamori et al, 2020) or sucrose (Freitas et al, 2015).…”

“…Not only hormones but also the effect of different concentrations of sucrose was examined during in vitro development and acclimatization of V. inflata (Freitas et al, 2015) and V. flammea (Sasamori et al, 2020). However, Vrieseas have slow growth (as usual in case of the other bromeliads, moderate development is typical), their acclimatization was not difficult, especially when in vitro plantlets were cultured previously on media with GA3 (Resende et al, 2016;Hernández-Meneses et al, 2018) or lower values of MS macronutrients (Sasamori et al, 2020) or sucrose (Freitas et al, 2015).…”