Tolerance of eggplant (Solanum melongena L.) seedlings to stress factors

• Main Authors: Agnieszka Sękara, Renata Bączek-Kwinta, Andrzej Kalisz, Stanisław Cebula
• Format: Article
• Language: English
• Published: Polish Botanical Society 2012-12-01
• Series: Acta Agrobotanica
• Subjects: eggplant; seedlings; heat stress; chilling stress; osmotic stress; H2O2 stress
• Online Access: https://pbsociety.org.pl/journals/index.php/aa/article/view/1308

The aim of the present study was to describe eggplant (Solanum melongena L.) tolerance to stress factors in the seedling stage as a basis for future studies on cross-tolerance to other stressors in subsequent stages of growth. After germination (3 days / 26oC), ‘Epic F1’ seedlings were exposed to chilling stress (3, 6 and 9oC × 48 h-1), heat stress (35, 40 and 45oC × 2 h-1), osmotic stress (mannitol 0.2; 0.6 and 1.0 M x 2 h-1), and oxidative stress (H2O2 0.2; 0.4 and 0.6 M × 2 h-1). A linear measurement of seedling radicle growth, electrolyte leakage and external symptoms of radicle damage under the stress conditions, compared to the non-stressed control, were analyzed. It was found that stressors in all experimental combinations caused a morphological and physiological response from eggplant seedlings. A significant reduction in linear growth of radicles, showed as an absolute length and as a percentage of the control, was found in the treatments exposed to chilling stress (3 and 6oC), heat stress (35, 40 and 45oC), osmotic stress (0.2, 0.6 and 1.0 M mannitol) as well as oxidative stress (0.2, 0.4 and 0.6 M H2O2). The changes in seedling length as a result of stress factors did not always correspond with the changes in seedling mass. Electrolyte leakage in the treatments exposed to the following stressors: 3 and 6oC as well as 0.6 M H2O2, was significantly greater than that observed in control plants. Based on the obtained results and microscopic observations of radicle damage, the following stressors can be identified as those which cause a physiological response without severe damage: 9oC × 48 h-1 (chilling stress), 35oC × 2 h-1 (heat stress), 0.2 M mannitol × 2 h-1 (osmoticum), and H2O2 0.2 M × 2 h-1 (oxidation factor). We propose these stressors as a basis for future studies on plant acclimation and hardening to other stresses.