Quinoa (Chenopodium quinoa Willd.) is a highly nutritious Andean seed crop which shows great potential to grow under a range of different stress environments. The objective of this study was to investigate the effect of drought on water regime and the growth of quinoa variety KVL52 in controlled conditions. The results of the present experiment indicate that the reaction of quinoa plants to drought are based on drought avoidance mechanisms: reduced transpiration and sustained water uptake. Transpiration was reduced due to the decrease of stomatal conductance and leaf area development. These results could be of practical importance for testing the possibility of growing quinoa as a new drought resistant crop in Serbia.

The effects of drought (partial root-zone drying-PRD and regulated deficit irrigation-RDI) and full irrigation (FI) on the expression of ABA biosynthetic genes (TAO1 and NCED), EIL1 gene and ABA content in the leaves of tomato wild-type (WT) and flacca mutant were investigated. Results confirmed differences in the expression of the investigated genes under the investigated treatments, during treatment duration as well as between investigated WT and flacca plants. The most significant differences between WT and flacca were found under PRD treatment. The similar expression pattern of all genes in the WT plants could indicate synergistic signaling pathways for ABA and ethylene. In flacca, reduced NCED and significant EIL1 expression might reflect the increase in ethylene production, which could influence the ABA signaling and production that occurred under PRD. Drought also induced an increase in ABA content that is most expressed in flacca under RDI.

Traditional crop varieties are useful sources of desirable characteristics for developing new cultivars with improved nutritive and sensory attributes. The aim of this study was to evaluate the fruit-quality parameters in three traditional tomato genotypes: pink, yellow and dark colors. The results showed that yellow-colored tomatoes had the highest TSS/TTA ratio and antioxidative activity, but the lowest content of lycopene and β-carotene. The genotypic differences in the carotenoid components were also confirmed by Raman spectroscopy. The advantage of the yellow-tomato genotype related to fruit-quality compounds compared to the other genotypes indicated its potential in a breeding program.

The reaction of leaf growth to drought stress is controlled by various hormones, among which ABA is one of the most important. The aim of this study was to examine the effects of ABA deficiency on tomato leaf response under severe drought stress. Therefore, ABA-mutant (flacca) and wild type (Ailsa Craig) were selected for research and in the stage of second flower truss anthesis plants were exposed to severe water deficit. The effects of severe drought on wild-type leaves and flacca mutant showed that, as a result of reduced ABA concentrations, flacca plants were exposed to a higher degree of stress than wild-type leaves, which had a negative impact on the examined physiological and biochemical parameters. Severe drought caused stomatal closure, decreased water potential, specific leaf area, and chlorophyll concentrations in the leaves in both genotypes, but this was more pronounced in the mutant. Wild-type plants have accumulated more vitamin C and ABA and have a higher total antioxidant capacity in the leaves in dry conditions than flacca mutants, which contribute to their better adaptive response to stress. Based on this, it can be assumed that the ABA mutation has led to a decrease in the capacity for oxidative stress products caused by severe drought stress.

Tomato fruit growth and productivity are complex processes depending on the interaction between physiological, genetic and environmental factors. Under current climate conditions of drought and scarce water supply, the challenge is to increase water use efficiency and to sustain tomato yield. Partial root-zone drying technique (PRD) is one of the irrigation methods with the potential to increase the water use efficiency and sustain the yield of many crops including tomato. The aim of presented results was to investigate the effects of PRD on tomato fruit growth, the activity of cell wall-associated peroxidase and ABA content in pericarp of tomato cultivar Ailsa Craig.The experiment was done in controlled conditions and plants under PRD received 70% of water given to full irrigated plants (FI) plants. In PRD irrigation is applied to one half of the root system while the other half dried down and then the treatment was reversed. ABA content in fruit pericarp was measured by ELISA test and cell wall-associated peroxidase activity by a guaiacol test.Fruit growth parameters showed that the maximal growth rate was significantly higher in FI plants than PRD but because the longer period of cell expansion the final diameter of PRD tomato fruits was slightly higher in PRD than in FI fruits. ABA content in tomato pericarp declined during the tomato development until the end of cell growth phase without significant differences between PRD and FI treated plants. The activity of peroxidase was significantly higher in PRD compared to FI. The significantly increase in the activity of enzyme cell wall-associated peroxidase in tomato fruit pericarp under PRD conditions coincided with the end of cell growth and the beginning of the ripening process. These results pointed out that this enzyme may control tomato fruit maturation