Influence of water stress on the nutritional quality of peach fruits

Abstract

Climate change, especially in arid and semi-arid areas, affects the production of fruit trees. In this region, fruit tree production requires an efficient water supply that maintaining safe and stable yields. The aim of this work is to study the influence of irrigation modes on the nutritional peach fruit quality and the control of water stress indicators rates. Our experiment was carried out at the CRRA Sidi Bouzid (Central-West of Tunisia). It focused on four varieties of peach (Prunus persica L), two early varieties (Flordastar (FS) and Early Maycrest (EMC)), a seasonal variety (Rubirich (RUB)) and a late variety (O'Henry (O'H)). Three different irrigation treatments were applied to the experimental plot: full irrigation (T1; 100% ETc), sustained deficit irrigation (T2; 50% ETc) and cyclical deficit irrigation (T3). The contents of total sugar, protein, and proline as well as some bioactive compounds and stress indicators (MDA, H2O2) were quantified in the exocarp and mesocarp of the fruit. The results showed that O’H fruits are the richest in phenolic compounds, as well as they have significant antioxidant activity. While, both FS tissues accumulated more sugar (55.15 and 81.31g/100g in the mesocarp and exocarp, respectively). Protein level was much higher under T2 and T3 treatments compared to the control treatment (T1) in all varieties. Water stress mainly T2 had significantly stimulated the accumulation of proline in the mesocarp of FS (the content increased from 0.61 to 2.1 µmol/100 g MS). In addition, in the four varieties, the cyclic water treatment (T3) has a significant effect on the accumulation of sugar and phenolic compounds. In conclusion, T3 seems to be the most adequate water regime to be applied in semi-arid region, saving water resources and maintaining fruit quality.