Initial Growth and Stomatal Characteristics of <i>Capsicum </i>Accessions Under PEG-Induced Water Stress In Vitro

Water stress compromises morphological and physiological aspects of pepper plants (Capsicum spp.), affecting their development. Polyethylene glycol (PEG) is widely used to simulate drought conditions in vitro, making it possible to assess crop tolerance to water restriction and assist in the selection of more resilient varieties. This study aimed to evaluate the in vitro germination, initial growth, and stomatal characteristics of ornamental pepper accessions subjected to different levels of water stress induced by PEG 6000. The study assessed seven pepper accessions and five concentrations of PEG 6000 (0%, 5%, 10%, 15%, and 20%) in Murashigue and Skoog media. Under PEG-induced water deficit conditions, no germination occurred at concentrations above 5%, unlike other studies observed with Capsicum. This result highlights the effect of genotype on tolerance to PEG levels. Water deficit resulted in a 13.1% reduction in germination compared to the control (p&lt;0.05), in addition to significantly affecting the percentage of dry matter in the shoot and roots. A decrease in stomatal density (51.6 to 35.4 stomata mm⁻²) and in the width of the stomatal midpoint (from 14.16 µm to 12.62 µm) was also observed. Among the genotypes evaluated, accessions CPCE 020, CPCE 018, and CPCE 011 showed better performance under stress, demonstrating greater tolerance to water deficit.