Alternative methods of estimating the water potential at turgor loss point in Acer genotypes

Abstract

Background Selecting for drought tolerance in urban tree species can have a significant influence on survival rates, aftercare requirements and performance. The water potential at turgor loss point (π tlp ) is gaining popularity as a trait to help determine drought tolerance to aid tree selection. Therefore, it is important to understand if differing methods used to measure or calculate π tlp deliver consistent results. Results The sensitivity of three methods used to determine this valuable selection parameter were evaluated. A classical pressure chamber, pressure–volume (P–V) curve method was compared with vapour-pressure osmometer (Vapro ® ) and dewpoint hygrometer (WP4C) methods. These methods were evaluated using closely related cultivars of Acer platanoides and A. pseudoplatanus ‘Negenia’. Conclusion Both the osmometer and hygrometer methods ranked genotypes with a very high similarity (R s = 1, R 2 = 0.96) and were able to identify significant differences between cultivars. This is the first study to demonstrate suitability of the dewpoint hygrometer in comparison to the vapour-pressure osmometer to measure π tlp . The P–V method was unable to identify differences between the cultivars tested. The Vapro and WP4C provide greater applicability than the conventional P–V method to studies requiring both high throughput and high sensitivity. Consistency of measurement type is however highly recommended in future studies as some differences were observed between Vapro and WP4C. Electronic supplementary material The online version of this article (10.1186/s13007-019-0410-3) contains supplementary material, which is available to authorized users.

Using botanic gardens and arboreta to help identify urban trees for the future

“…This analysis supports previous studies conducted with Acer (Sjöman et al., 2015) that the technique of using vapor pressure osmometry to predict Ψ P0 (via Ψ π100 ) is sensitive enough to resolve differences in drought tolerance between closely related genotypes. From a practical perspective, the technique has been proven to be more time efficient (Bartlett, et al., 2012) and more sensitive than pressure‐volume curves (Banks & Hirons, 2019): a more traditional technique used to determine Ψ P0 in leaves. Therefore, it is likely to be a useful technique to identify which plant lineages are likely to be contributing to drought tolerance within novel breeding programs.…”

“…From a practical perspective, the technique has been proven to be more time efficient and more sensitive than pressure-volume curves (Banks & Hirons, 2019): a more traditional technique used to determine Ψ P0 in leaves. Therefore, it is likely to be a useful technique to identify which plant lineages are likely to be contributing to drought tolerance within novel breeding programs.…”

Aerosol Impacts on Water Relations of Camphor (Cinnamomum camphora)

“…The hypothesis of lower leaf water potential at wilting (i.e., turgor loss point, π tlp ) by aerosols was also not confirmed. π tlp is considered another important determinant of ecological and physiological drought tolerance, which is also strongly correlated with the cell solute potential at full hydration (i.e., osmotic potential, π o ) (Bartlett et al, 2012a , b ; Banks and Hirons, 2019 ). Previous research has focused on π tlp of plant species such as woody species, crops, and herbaceous grassland species, concluding that this indicator of drought tolerance varied across species and environmental conditions; π tlp is as well correlated slightly with several leaf functional traits such as leaf dry matter, leaf vulnerability to hydraulic failure, leaf toughness, and leaf thickness (Maréchaux et al, 2015 ; Griffin-Nolan et al, 2019 ).…”

“…where C o is the molar solute concentration (mmol kg −1 ), R is the universal gas constant 8.3144598E-0.6 (m 3 MPa K −1 mol −1 ), T is the temperature (K) (Khare, 2015 ). Due to the strong correlation between π o and π tlp (Bartlett et al, 2012a ), π tlp was then calculated from π o by using the adapted regression Equation (2) from previous research (Bartlett et al, 2012b ; Sjöman et al, 2015 ; Banks and Hirons, 2019 ):…”

Evaluation of Alnus subcordata for urban environments through assessment of drought and flooding tolerance

“…The vapour pressure osmometry technique for prediction of Ψ P0 (via Ψ π100 ) is sensitive enough to resolve differences in drought tolerance between different treatments. From a practical perspective, the technique has been proven to be more time-efficient (Bartlett et al, 2012b) and more sensitive than pressure-volume curves (Banks & Hirons, 2019), a more traditional technique used to determine Ψ P0 in leaves. Therefore vapour pressure osmometry can be used to identify plant lineages likely to contribute to drought tolerance.…”