*3.3. Stomata Analysis*

In this study, stomata were present in both adaxial and abaxial leaf surfaces of both banana varieties under the different light sources, thus characterizing them as amphistomatic (Figure 3). Light source influenced stomata number of both banana varieties (Table 2). Some significant differences were observed between lighting treatments, following the same pattern observed for relative chlorophyll content. Overall, there were no significant differences in the effect of light sources on the adaxial number of stomata (AdSN) for both banana varieties, except for LED-2 and FL, which were slightly higher than LED-1 (Table 2). For the adaxial surface, plantlets had an average leaf stomata number per mm2 of 22.8 and 24.4 under LED-1, 28.4 and 25.8 for LED-2, and 30.0 and 32.0 under FL for Musa 'Little Prince' and Musa 'Truly Tiny', respectively (Table 2). A similar trend was observed for the abaxial number of stomata per mm2 (AbSN) for both varieties with 75.4 and 92.0 under

LED-1, 67.6 and 94.2 under LED-2 and 83.6 and 101.6 under FL for Musa 'Little Prince' and Musa 'Truly Tiny', respectively (Table 2). The size of the stomata evaluated by length and width showed some variation for both adaxial and abaxial surfaces under the different light sources and for both varieties. The length of the adaxial surface stomata (AdSL) was higher for 'Little Prince' under FL but not significantly different for 'Truly Tiny' under LED-2 and FL (Table 2). The length of the abaxial surface stomata (AbSL) was higher for both varieties under LED-2 and FL (Table 2). The width of the adaxial surface stomata (AdSW) was higher for both varieties under FL, but for the abaxial surface stomata (AbSW), width showed no significant differences (Table 2).

**Figure 3.** Stomatal prints of abaxial and adaxial leaf surfaces of in vitro banana leaves (Musa 'Little Prince' and 'Truly Tiny') under different light sources. LED-1 = 116 μmol m−<sup>2</sup> s−1; LED-2 = 90 μmol m−<sup>2</sup> s<sup>−</sup>1, fluorescent lighting (FL) = 100 μmol m−<sup>2</sup> s<sup>−</sup>1. Bars = 50 μm.

**Table 2.** Effects of light sources on stomata number (per mm2) and size (μm) in leaves of two ornamental banana varieties grown *in vitro*; Musa 'Little Prince' and 'Truly Tiny'. LED-1 = 116 μmol m−<sup>2</sup> s<sup>−</sup>1; LED-2 = 90 μmol m−<sup>2</sup> s<sup>−</sup>1; fluorescent light (FL) = 100 μmol m−<sup>2</sup> s<sup>−</sup>1.


\* Means within columns followed by the same letter are not significantly different at *p* ≤ 0.05 according to the LSD (Least Significance Difference) test. The tests were conducted independently within each parameter (adaxial and abaxial stomata number, adaxial and abaxial stomata size). AdSN = Adaxial Stomata Number; AbSN = Abaxial Stomata Number; AdSL = Adaxial Stomata Length; AbSL = Abaxial Stomata Length; AdSW = Adaxial Stomata Width; AbSW = Abaxial Stomata Width.
