Effect of light and sucrose on photoautotrophic and photomixotrophic micropropagation of Physalis angulata

The biotechnological interest in genus Physalis has increased in the last decades, however, there are still few micropropagation studies of this genus. The objective of this study was to evaluate P. angulata photoautotrophic and photomixotrophic micropropagation with gas exchange under seven light spectra and five concentrations of sucrose. Lighting were yellow, blue, white, red, green, red + blue LEDs and natural light filtered by mesh. Sucrose concentrations were 0, 7.5, 15, 22.5 and 30 g.L-1. Phytotechnical, anatomical features and photopigment contents were evaluated through stem and root segment length, leaf number, leaf area, chlorophyll a and b contents, carotenoids, adaxial epidermis, palisadic and spongy parenchyma and abaxial epidermis. The data were compared by Scott-Knott's mean test and principal components analysis using the R software. Comparing the variables within lighting types, it was observed that only the screen treatment, screen-filtered natural illumination, obtained assessment in all variables. Comparing the levels of sucrose, it was observed that the treatment 15 g.L-1 sucrose obtained the highest number of averages with maximum evaluation. It was concluded that the natural light filtered by screen with 50% of shading allowed the photoautotrophic micropropagation of P. angulata. Better development results were observed in photomixotrophic micropropagation with 15 g.L-1 of sucrose.

The Growth Improvement of Grammatophyllum scriptum (Lindl.) Bl. In Vitro Plantlet using Photoautotrophic Micropropagation System

To improve the growth of Grammatophyllum scriptum (Lindl.) Bl. in vitro plantlet, a photoautotrophic micropropagation system (PMS) was developed by growing in vitro plantlet on VW medium with varying concentration of sucrose (0, 5, 10, and 20 g/L) and additional carbon dioxide from the air (bottle covered with cap or filter). The result showed that the leaf length would increase up to 6.5 cm with PMS and it would keep growing by the adding of 5 g/L sucrose. Average number of leaves increased by 6.7 strands with PMS and the addition of sucrose increased the average quantity of leaves up to 7.7 strands. Average number and root length would increase with PMS and would even increase more with 5 g/L sucrose addition. PMS with 5 g/L sucrose can increase chlorophyll a and b concentration. The number of stomata per unit area in PMS was lower than closed culture. This shows that PMS can increase the growth of G. scriptum in vitro plantlet and the growth increase would be effective if it is combined with sucrose addition.