Effects of drought on morphological and physiological parameters of tomato leaf

It is well-known that drought stress is characterized by reduction of soil water content, diminished leaf water potential and turgor loss, stomatal closure and decreased rate of cell enlargement and growth. The magnitude of these changes and their consequences for plant metabolism, growth and development depends on the degree of stress and plant resistance to drought. The aim of presented results was to investigate the effects of drought on leaf characteristics (length, area and specific leaf area) and stomatal conductance in two different tomato cherry cultivars (LA1420 and Plovdiv).The experiment was conducted in glasshouse conditions. Plants were exposed to drought by withholding irrigation of substrate in the pots (soil water content ca.25%), while in control conditions plants received full substrate water holding capacity (soil water content ca. 75%). Leaf length was measured by ruler, their DW after drying procedure, while leaf area was measured by area meter. Specific leaf area (SLA) was calculated on the base of relationship between leaf area and leaf DW. Stomatal conductance was measured by porometer.Obtained results showed genotypic differences between tomato cultivars in the sensitivity of investigated parameters to drought. Higher stomatal sensitivity to drought and consequently bigger reduction of stomatal conductance and transpiration in cultivar LA1420 comparing to Plovdiv, contributed to the to ability of LA1420 plants to retain a relatively high level of leaf hydration necessary to sustained leaf area development in drought conditions.