Sustainable strategies for irrigation in salt-prone Mediterranean: SALTMED

The effects of salinity on growth and yield of tomato varieties growing in a greenhouse in Spain were also investigated. Salinity reduced the commercial yield, mainly due to a decrease in fruit weight and to a lesser extent by a reduction in fruit number and by increasing blossom end rot in fruits. Evaluation of pre-treatment of seedlings with drought or salinity in the laboratory demonstrated that tomato plants 'haloconditioned' at the 3-5-day-old stage produced more shoot and root biomass than non-conditioned control plants. The physiological traits, 'root Na selectivity', 'leaf tissue tolerance', 'leaf-to-leaf tolerance' and the 'K/Na ratio' were evaluated as tools for breeding varieties with enhanced tolerance to salt. Selectivity and K/Na appeared to be the most promising characters for breeding purposes. Heritability of physiological traits was estimated in a set of 135 F8 recombinant inbred lines from a cross between Lycopersicon pimpinellifolium and L. esculentum. Heritabilities of water use efficiency (WUE) were particularly high, in both control and saline conditions.