Response of two tomato lines to drought stress based on the proline content in fruits and yield

Abstract

Drought is one of the factors that most reduces crop productivity. Water deficit affects the morphological and physiological parameters of the plant, and some of them can be used as indicators of plant tolerance to drought. The aim of this experiment was to evaluate the effects of water deficit on proline content in fruits, as well as yield parameters of two tomato lines (M7 and R83), that in previous research showed a contrasting response in vegetative phase. Tomato plants were grown in a glasshouse in pots during three months after planting of seedlings. Two water regimes were applied (optimal field capacity and water deficit - reduction of water for 30% compared to control). The content of proline was significantly higher in the fruits of both tomato lines exposed to water stress. The increase in proline content under stress conditions compared to control was higher in fruits of line M7 (81.0%) compared to line R83 (35.4%). Our results showed that water deficit significantly affected fruit diameter, length and biomass of the fruit, but did not affect the number of fruits per plant in both tested tomato lines. The reduction of fruit yield in water deficit conditions was higher for line M7 (31.5%) in comparison to line R83 (20.7%). Based on the obtained results, the R83 line showed a potentially better response to drought stress at fruit level, which is in accordance with our research results conducted on the same lines in the vegetative phase.