Diurnal gas exchange: interaction between foliar and non‐foliar tissues

Fruit growth results from the balance between influx of water, nutrients and assimilates and losses due to fruit transpiration and respiration (Windt et al., 2009). Water influx in the fruits occurs in part through the xylem in competition with the rest of the plant, and for that reason fruit growth is sensitive to changes in foliar transpiration (Hanssens et al., 2015). Assimilates can originate from foliar photosynthesis or from the fruit itself in proportion that varies between species (Cocaliadis et al., 2014; Simkin et al., 2020). For example, the surface area of a mature green cucumber (Cucumis sativa L.) fruit is comparable with that of a functional leaf and makes an important contribution in term of photo-assimilates to fruit growth (Sui et al., 2017). In tomato, fruit photosynthesis is present at early developmental stage, but there is still a debate on the importance of its contribution to the growth (Cocaliadis et al., 2014). Therefore, gas exchange can be an important determinant of the fruit growth even though its diurnal variations are not well characterized, especially in interaction with foliar tissues.

In this project, you will perform diameter measurements and diurnal gas exchange measurements on attached fruits of tomato/cucumber at different developmental stage using a custom gas exchange chamber (Li-6800). To study the effect of the whole plant on the fruit gas exchange, the plant canopy will be subjected to different diurnal environmental conditions (high/Low light, High [CO2]).

Used skills

  • Gas exchange measurements
  • Data analysis

Interested in doing a BSc or MSc thesis at HPP? Please contact the HPP student coordinator Katharina Hanika.