Light-emitting diodes (LEDs) have become very popular for the production of horticultural crops. LEDs represent an alternative lighting source to regular fluorescent (FL) bulbs, increasing the quality of plants and minimizing production costs. LEDs also provide selective light intensity and quality, suitable for commercial micropropagation. The objective of this study was to evaluate the growth and development of in vitro ornamental bananas under different light sources. Two ornamental banana varieties were selected for this study: Musa ‘Little Prince’ and Musa ‘Truly Tiny’. Light quality and intensity of three different light sources were evaluated: LED-1 (116 μmol m−2 s−1), LED-2 (90 μmol m−2 s−1), and FL (100 μmol m−2 s−1). Length and biomass of plantlets were greater under LED-1 compared to FL but not significantly different from LED-2. The fresh and dry weight of shoots and roots, number of leaves, and number and length of roots were not significantly different between treatments. Chlorophyll content was greater under LEDs. Leaf number and stomata number and size were greater under FL. Our results indicate that shoot length and biomass could be improved by optimizing light quality and intensity. Different responses to light sources between the two banana varieties also indicated a genotype effect.

Brassavola nodosa (L.) Lindl. is an epiphytic orchid with great potential for the ornamental plant industry. The lack of information on propagation and production techniques limits the development of large-scale commercial production. Furthermore, this species is experiencing a reduction in population due to habitat destruction, the impact of climate change, and over-collection from native habitats. This study aimed at developing an efficient protocol for micropropagation of B. nodosa, which could be valuable towards the large-scale commercial production as well as for conservation of this species. Six different concentrations of plant growth regulators (BA or IBA, with or without adenine sulfate) were evaluated in modified Murashige and Skoog (MS) medium for shoot multiplication. In addition, two concentrations of either NAA or IBA were evaluated for rooting. Explants were cultured under three different culture media conditions: semi-solid medium, liquid medium (partial immersion), and liquid medium (complete immersion). Results indicate that B. nodosa could be successfully micropropagated in liquid culture with partial immersion. The modified MS medium supplemented with 2.0 mg L−1 BA and 30.0 mg L−1 adenine sulfate resulted in higher multiplication rates. Rooting was obtained using either 0.5 mg L−1 NAA or 1.0 mg L−1 IBA with no significant differences between both rooting treatments. Plantlets achieved 100% ex vitro survival after 30-d acclimatization.

Brassavola nodosa (L.) Lindl. is a tropical epiphytic orchid showing characteristics of interest for the ornamental nursery industry. However, problems with traditional propagation methods limit the development of a large-scale commercial production system. In addition, this species is considered endangered due to the reduction in population caused by habitat destruction, climate change and overcollection from native areas. The use of micropropagation has been investigated for this species, and the use of liquid in vitro systems showed potential for use of temporary immersion bioreactors for micropropagation of B. nodosa. This study evaluated the e ciency of the SETIS™ bioreactor system for the micropropagation of B. nodosa by adjusting parameters of immersion (frequency and duration) and by comparing it to conventional semi-solid culture systems. Results indicate that temporary immersion of B. nodosa explants with a frequency of 2 h and duration of 2 min returned the highest multiplication rates, with 4.6 shoots produced per explant compared with 2.8 shoots per explant in semi-solid agarbased systems. The use of bioreactors also promoted increased growth and development and in vitro rooting, therefore improving survival and facilitating acclimatization of in vitro-derived plantlets. This is the rst study demonstrating a successful protocol for large-scale micropropagation of B. nodosa using SETIS™ bioreactors, which could have signi cant value and impact for the commercial production of this species as well as for conservation purposes. Key MessageMicropropagation of Brassavola nodosa was achieved using SETIS temporary immersion bioreactors, showing good multiplication rates, increased growth and development and in vitro rooting, thus improving survival and acclimatization ex vitro.

Orchids, with their astonishingly stunning flowers, dominate the international floricultural market. They are considered prized assets for commercial applications in pharmaceutical and floricultural industries as they possess high therapeutic properties and superior ornamental values. The alarming depletion of orchid resources due to excessive unregulated commercial collection and mass habitat destruction makes orchid conservation measures an extreme priority. Conventional propagation methods cannot produce adequate number of orchids, which would meet the requirement of these ornamental plants for commercial and conservational purposes. In vitro orchid propagation using semi-solid media offers an outstanding prospect of rapidly producing quality plants on a large scale. However, the semi-solid (SS) system has shortcomings with low multiplication rates and high production costs. Orchid micropropagation using a temporary immersion system (TIS) overcomes the limitations of the SS system by reducing production costs and making scaleup and full automation possible for mass plant production. The current review highlights different aspects of in vitro orchid propagation using SS and TIS and their benefits and drawbacks on rapid plant generation.

Culture medium and light are important factors that affect the process of in vitro propagation of plants. Particularly for orchids, diverse culture media have been evaluated for micropropagation of many species and hybrids. More recently, light-emitting diodes (LEDs) have become widely used in agriculture, including micropropagation commercial operations, resulting in increased production and reduced costs compared to traditional fluorescent lights. Brassavola nodosa (L.) Lindl. is an orchid, with great potential for commercialization as a potted flowering plant due to the beauty and fragrance of its inflorescences. In this study, we evaluated the effects of culture media (VW, MS, and ½ MS) and light sources (three LED sources and one fluorescent light source) on the micropropagation of B. nodosa orchids. VW medium resulted in the best growth and development of in vitro shoots compared to MS and ½ MS media. Light sources with lower intensity, such as LED-3 (80 μmol m−2 s−1 PPFD) resulted in the best plant performance in vitro, while LED-2 (1015 μmol m−2 s−1 PPFD) showed the best plant performance ex vitro. Rooting was obtained in vitro without the need for a rooting phase. Survival ex vitro was 100%, with the successful growth and development of in vitro-derived plantlets during acclimatization.