Seed priming in Clitoria ternatea L. with multi-walled carbon nanotubes: A physicochemical and morphological approach

Clitoria ternatea L. is valued for its ornamental characteristics, medicinal properties, and culinary uses. However, efficient production of this species is constrained by seed coat dormancy, which impedes germination and seedling production. This study aimed to explore the physicochemical and morphological aspects of C. ternatea seeds, focusing on overcoming dormancy by applying multi-walled carbon nanotubes (MWCNTs) functionalized with carboxylic acid. The seeds were characterized by their physical, chemical, and mineral composition. Characterization included color dominance, geometry, thousand seed weight, and moisture content analyses. The seeds were treated with different concentrations (0, 100, 200, 400, 800 mg L-1) of multi-walled carbon nanotubes (MWCNT) during 24 hours of soaking. Then the germination rates were evaluated and morphological analysis was performed using scanning electron microscopy. Regarding the morphometry of the seeds, they were characterized by an oblong shape, a predominance of black tegument coloration, high levels of proteins, carbohydrates, lipids, fibers, and the presence of minerals such as potassium, magnesium, iron, and calcium. Seeds soaked in MWCNTs at a concentration of 200 mg L-1 exhibited an increase in germination percentage and the formation of normal seedlings compared to the control group (seeds soaked in water). The results suggest that MWCNTs can help to overcome seed dormancy and improve the quality of the resulting seedlings. Image analysis and scanning electron microscopy were crucial in understanding the physicochemical characteristics of the seeds and their changes upon exposure to MWCNTs.