A high-throughput approach for quantifying turgor loss point in grapevine.

Area of Science:

• Plant physiology
• Agricultural science
• Environmental science

Background:

• Quantifying crop drought tolerance is crucial for agricultural adaptation to climate change.
• Drought response traits in grapevines are key research areas in viticulture.
• Turgor loss point (TLP) is an important indicator of plant drought tolerance, but its estimation via pressure-volume (P-V) curves is labor-intensive.

Purpose of the Study:

• To evaluate the efficacy of a dewpoint hygrometer for rapid estimation of TLP in grapevines.
• To compare TLP measurements from a dewpoint hygrometer with traditional P-V curve analysis.
• To assess the dewpoint hygrometer's ability to detect intraspecific variation in TLP across grapevine clones and species.

Main Methods:

• Leaf samples from 12 Vitis vinifera subsp. vinifera clones and one Vitis riparia were analyzed.
• TLP was measured using both a dewpoint hygrometer and traditional P-V curves.
• Statistical analyses, including correlation and t-tests, were used to compare the two methods at leaf and species/clone levels.

Main Results:

• Dewpoint hygrometer measurements of TLP closely approximated P-V curve results at the leaf level (r² = 0.254, Spearman's ρ = 0.459).
• At the species/clone level, dewpoint hygrometer and P-V curve TLP estimates were statistically correlated (r² = 0.304) and conserved rankings.
• The dewpoint hygrometer method, taking 10-15 minutes per measurement, captured fine-scale intraspecific TLP variation, unlike P-V curves (2-3 hours per measurement).

Conclusions:

• The dewpoint hygrometer is a viable, high-throughput tool for rapidly estimating TLP in grapevines.
• This method allows for increased replication in assessing drought tolerance traits, benefiting crop screening.
• The dewpoint hygrometer's efficiency can significantly aid research in grapevine and other crop drought tolerance.