Preliminary high-throughput phenotyping analysis in grapevines under drought

This study reports correlative information between leaf water potential (Psi), total leaf area of droughted grapevines (Vitis vinifera L.) and non-destructive image analysis techniques. Four groups of 20 potted vines each were subjected to various irrigation treatments restoring 100% (control), 75%, 50% and 25% of daily water consumption within a 22-day period of drought imposition. Leaf gas exchanges (Li-Cor 6400), Psi (Scholander chamber), fluorescence (PAM - 2500), RGB and NIR (Scanalyzer 3D system, LerrmaTec GmbH phenotyping platform) data were collected before and at the end of drought imposition. Values of Psi in severely stressed vines (25%) reached -1.2 MPa pre-dawn, in turn stomata' conductance and photosynthesis reached values as low as approx. 0.02 mol H2O m(-2) s(-1) and 1.0 mu mol CO2 m(-2) s(-1), respectively. The high-throughput analysis preliminarily revealed a correlation between Psi(stem) and NIR Color Class (R-2=0.80), and that plant leaf area might be accurately estimated through imagine analysis (R-2=0.90).