Elevated Temperature Increased Stomata Size and Leaf Photosynthesis in Shiraz Grapevine

The aim of this work was to investigate the effect of elevated temperature, and its interaction with water supply, on stomata size and leaf photosynthesis in shiraz grapevine in Barossa Valley (South Australia) The experiment combined two thermal regimes (control and elevated day/night temperature) and two water regimes (irrigated and water deficit). Temperature regimes were control with background ambient temperature, and elevated day/night temperature achieved with an open-top heating system that combines passive heating on clear days, active heating on overcast days and during the night, and mobile panels that regulate the release of excess heat as necessary. Stomata size was measured in using the technique of nail polish and sticky-tape imprints from the abaxial epidermis. Stomatal length and width were measured s with at a magnification of x 200. Li-Cor 6400 was used (Li-Cor Environmental Sciences, Lincoln, Nebraska, USA) to measure photosynthetic rate. We found that elevated temperature increased stomata size and leaf photosynthesis in Shiraz grapevine. This response likely contributes to evaporative cooling and adaptation to elevated temperature.