In vitro plantlets were cultured on Murashige and Skoog (MS) medium [24] supplemented with 8.8 μM benzylaminopurine (BAP) and 30 g L⁻¹ sucrose. The pH of the medium was adjusted to 5.8, and it was solidified with 8 g L⁻¹ agar (agar-agar, Sigma Aldrich Inc., St. Louis, MO, USA).
LEDs offer several advantages over fluorescent bulbs, including longer lifespan, smaller size, and minimal heat production [3]. Additionally, LEDs can influence plant growth and the production of secondary metabolites, as shown in studies with Pfaffia glomerata [12]. The spectral distribution of light primarily affects plant growth via photosynthesis, influencing not only growth but also plant morphology. Photon flux density (PFD) also plays a role in shaping plant morphology, and interactions between light spectrum and intensity are crucial to understanding their combined effects on plant development [13].
Asexual propagation methods are the primary means of banana production, especially given the high sterility and polyploidy of cultivated banana varieties and hybrids [14]. However, traditional propagation techniques are associated with various plant diseases, such as black sigatoka, fusarium wilt, banana bunchy top virus, burrowing nematodes, and banana weevil borer [15]. Consequently, micropropagation has become a widely adopted method for producing disease-free, clean banana plant material [16–20]. Additionally, tissue culture allows for the mass propagation of elite banana varieties, promoting healthier, disease-free crops. The use of LEDs in micropropagation may offer benefits such as improved plant quality and reduced energy consumption. Previous studies have investigated the use of LEDs in banana in vitro cultures, focusing on specific wavelengths, LED ratios, or lower light intensities (45–75 μmol m⁻²s⁻¹ PPFD) [21–23].
The primary aim of this study was to assess the growth and development of in vitro ornamental banana plants under different light sources, comparing simple LEDs with traditional fluorescent lighting. In addition to growth parameters, the study also evaluated relative chlorophyll content, leaf stomatal characteristics, and anatomical features.
2. Materials and Methods
2.1. Plant Material and Culture Establishment
Two ornamental banana varieties, Musa ‘Little Prince’ and Musa ‘Truly Tiny’, were sourced from AgriStarts, Inc. (Apopka, FL, USA). These are dwarf varieties of the Cavendish banana, characterized by their compact growth and thick, dark green leaves. Musa ‘Little Prince’ has a robust trunk and is typically used as an ornamental plant indoors or as a landscape feature outdoors. Musa ‘Truly Tiny’ is an extremely dwarf variety, known for producing the smallest edible bananas in the world. Both varieties are highly desirable as ornamental plants and are commonly propagated through tissue culture, exhibiting similar growth rates.