LAUSR

Abstract Light quality can change the morphogenesis of seedlings through receptors. They absorb and interpret light in the red and blue regions of the spectrum, being a viable strategy to increase the morphophysiological quality of gabiroba seedlings [Campomanesia pubescens (DC.) O. Berg]. This species is native to the Cerrado, and has great ornamental, medicinal and food potential. The aim of this study was to analyze the morphological and physiological responses of C. pubescens seedlings grown in different light qualities, subsidizing future studies with ex vitro and in vitro propagation of this species. Light-emitting diodes (LEDs) were used at the monochromatic red (R) (600–700 nm), monochromatic blue (B) (400–490 nm), blue/red (1:1) and white (W) (400–700 nm) at 50 ± 5 μmol m−2 s−1, in a 16-h photoperiod. Biometry, dry matter, leaf area, leaf anatomy, chlorophyll fluorescence, chloroplast pigments and malondialdehyde content (MDA) were evaluated. Variations in growth and physiological parameters were observed in response to different light qualities. Oxidative damages were observed by the significant increase in MDA when seedlings were grown under red LED. This damage had negative repercussions on the biometric responses of plants, affecting their physiology. On the other hand, higher biometrics were observed when the plants were grown in white and blue-red LEDs. Greater stomatal density, stomatal functionality and, consequently, higher Fv/Fm, YII, led to a higher leaf and stem dry mass when grown in white and blue/red LEDs. This study contributed to a better understanding of the impact of different light qualities on the growth and development of C. pubescens seedlings and may contribute with more detailed studies to produce seedlings with better quality.