Factors controlling drought resistance in grapevine (Vitis vinifera, chardonnay): application of a new microCT method to assess functional embolism resistance.

Premise: Quantifying resistance to embolism in woody plants is important for understanding their drought response. Methods to accurately quantify resistance to embolism continue to be debated.

Methods: We used a new microCT-based approach that quantifies embolized conduits and also analyzes conductive conduits by using an x-ray-dense, iodine-rich tracer that moves though the vascular system and can easily be observed in microCT images.

Embolism resistance of different aged stems of a California oak species (Quercus douglasii): optical and microCT methods differ from the benchtop-dehydration standard.

Vulnerability of xylem to embolism is an important trait related to drought resistance of plants. Methods continue to be developed and debated for measuring embolism. We tested three methods (benchtop dehydration/hydraulic, micro-computed tomography (microCT) and optical) for assessing the vulnerability to embolism of a native California oak species (Quercus douglasii Hook.

Direct comparison of four methods to construct xylem vulnerability curves: Differences among techniques are linked to vessel network characteristics.

During periods of dehydration, water transport through xylem conduits can become blocked by embolism formation. Xylem embolism compromises water supply to leaves and may lead to losses in productivity or plant death. Vulnerability curves (VCs) characterize plant losses in conductivity as xylem pressures decrease.