Candle soot colloids enhance tomato (Solanum lycopersicum) seed germination and seedling quality

The effect of candle soot colloids, a novel nanomaterial from candle combustion that we developed previously, on tomato (Solanum lycopersicum) seed germination and seedling vigor was investigated. Candle soot colloids were applied at different concentrations and hydrophobicities to tomato seeds and germination parameters and seedling vigor characteristics, such as length, fresh weight, dry weight, chlorophyll, and carotenoids, were measured. It was found that candle soot colloids significantly improved germination speed, seedling length, and seedling fresh weight compared to the control. The adherence of soot particles to the trichomes on the seed surface, which may help seeds retain moisture and stay hydrated, was observed. The chemical composition of the soot samples was analyzed using gas chromatography-time of flight mass spectrometry and two different chemical constituents in hydrophilic and hydrophobic soot samples that may affect seed germination were identified. A new potential use of candle soot colloids as plant growth-promoting agents and insights into the effects of nanomaterials on plant physiology and biochemistry were revealed by this study.