SENSITIVITY OF THE PHOTOSYNTHETIC APPARATUS IN APPLE TREES UNDER WATER DEFICIT [CITLIVOST FOTOSYNTETICKÉHO APARÁTU JABLONÍ PŘI PŮSOBENÍ VODNÍHO DEFICITU]

Abstract

The domestic apple tree (Malus domestica Borkh.) is one of the most important fruit species in the world. At the same time, the area under cultivation is also decreasing, one of the reasons being drought. Drought adversely affects the physiological, biochemical and growth processes of plants. The effect of water deficit was monitored under partially controlled conditions of the foliar cover in selected apple genotypes: ‘Gala Galaval’, ‘Idared’, ‘Frosta’, B 11, HL 53, HL 155-05 in a container experiment, where water deficit was induced for 14 days followed by one week of rehydration. The experiment was carried out at developmental stages 31 BBCH to 67 BBCH. Among the physiological characteristics, pigment content, photosynthesis and transpiration rates, chlorophyll fluorescence were monitored. The results show that the effect of water deficit leads to a decrease in all the observed characteristics. Under the influence of rehydration, all physiological parameters increased, but the values of control plants were not reached. The rehydration period of 7 days is short for apple trees. The results show that the increase in transpiration values during the dry season in the varieties ‘Gala Galaval’ and ‘Frosta’ makes them unsuitable for drier areas. ‘Idared’, on the other hand, is a more plastic variety. The genotypes HL 53, HL 155-05 appear to be promising genotypes with potential for further research.

Keywords

• water deficit
• drought
• apple tree
• malus sylvestris
• gas exchange
• pigments
• fluorescence