Physiological potential of bell pepper seeds under heat and salt stress

Peppers (Capsicum annuum L.) are a nutritionally important vegetable grown in Brazil. Abiotic stresses, such as heat and salt, directly affect the germination process of seeds and compromise their yield. This study aimed to evaluate the effects of heat and salt stress on the physiological potential of bell pepper seeds. The experiment was conducted using a completely randomized design arranged in a 4x5 factorial scheme: heat stress with four temperatures (20 degrees C, 25 degrees C, 30 degrees C, and 35 degrees C) and salt stress with five concentrations of NaCl (0.00, 0.075, 0.150, 0.225, and 0.300 mM). The physiological potential of the seeds was assessed using germination and vigor tests. The interaction between temperature and NaCl concentration significantly influenced all the variables studied. In germination, first germination count, germination speed index, and seedling length, the effect of the interaction was adjusted to a quadratic regression, in which there was a decrease in the variables mentioned until approximately the concentration of 0.150 mM NaCl for the concentrations of 0.225 and 0.300 mM, there was an increase, but it was not superior to the control (0.00 mM). Bell pepper seeds are sensitive to heat and salt stress in which the physiological potential of the seeds was negative at temperatures of 20 degrees C and 35 degrees C and with increasing concentrations of NaCl, highlighting the importance of strategies to optimize germination and initial growth of seedlings under such conditions.