Blue and red LED lighting effects on plant biomass, stomatal conductance, and metabolite content in nine tomato genotypes

A collection of nine tomato genotypes was chosen based on their diversity, phylogeny, availability of genome information, and agronomic traits. The objective of the study was to characterize the effect of red and blue LED (light-emitting diode) lighting on physiological, morphological, developmental, and chemical parameters. Two LED light treatments were imposed: (1): 100% red and (2): 88% red/12% blue (peak emission at 662 and 456 nm for red and blue light, respectively). The combination of blue and red LED lighting increased total dry matter in seven of the nine genotypes compared to red. Upward or downward leaf curling was observed in all genotypes in the 100% red treatment. Stomatal conductance was not affected much by additional blue light, but blue light increased chlorophyll and flavonol contents in three genotypes. The exposure of tomato plants to a combination of red and blue LEDs alleviated leaf morphological abnormalities and enhanced plant biomass, and variably affected stomatal conductance and secondary metabolism compared to red light alone.