Productivity versus drought adaptation in olive leaves: Comparison of water relations in a modern versus a traditional cultivar
Abstract
The physiological traits that set the tradeoff between productivity and drought adaptation in plants are still under debate. To reveal these traits, we compared the water relations of two olive (Olea europaea) cultivars: “Barnea”—a highly productive modern cultivar; and “Souri”—a drought‐adapted traditional cultivar. We hypothesized that Souri has lower hydraulic conductivity and lower hydraulic vulnerability. The hypothesis was tested at the leaf level. The soil volumetric water content (θ), stem water potential (ΨS), and gas exchange were measured in both cultivars while they dried until a significant reduction in their maximal photochemical potential (Fv/Fm S, approaching zero at −8 MPa compared with S, while maintaining near optimal (Fv/Fm). However, both cultivars significantly reduced their Fv/Fm (θ, suggesting that the capability to sustain a low θ is not the issue. Instead, Souri's lower transpiration enabled it to withstand a longer drought while avoiding low θ. Barnea's larger xylem vessels and hydraulic conductivity supported higher stomatal conductance (gs) and assimilation rate, which nurtured its higher productivity but resulted in quick depletion of θ. These results suggest that hydraulic resistance or the ability to sustain low θ do not set the tradeoff between productivity and drought adaptation in olive leaves.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 24, 2021
- Source ID
- 10.1111/ppl.13580
Entities
People
- Arnon Dag
- Hanita Zemach
- May Avraham
- Oded Barzilai
- Uri Hochberg
- Yonatan Sorek
Organizations
- Hebrew University of Jerusalem