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  • Factors controlling drought resistance in grapevine ( Vitis vinifera , chardonnay): application of a new micro CT method to assess functional embolism resistance
Title: Factors controlling drought resistance in grapevine ( Vitis vinifera , chardonnay): application of a new micro CT 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 microCTimages. Many previous microCTstudies assumed that all conduits were initially conductive, which may not be the case if there are developing or occluded conduits. We compared microCTresults to a standard benchtop dehydration method and a centrifuge method. During dehydration, we measured gas exchange and quantified water potential at mortality.

 Results

Our microCTcurves agreed with previously published microCTcurves from the same greenhouse‐grown cultivar. We found a significant difference in embolism estimates if we assumed that all water‐filled conduits were functional rather than only those containing tracer. Embolism estimates from microCTdiffered from both the benchtop and centrifuge methods. The benchtop and centrifuge methods did not differ from one another.

 Conclusions

The new microCTmethod presented here is valuable in sampling species that may contain nonconductive conduits. Disagreement between microCTand two other methods was likely due to differences in the ways they quantify embolism. MicroCTassess the theoretical effect of embolism, whereas benchtop and centrifuge methods directly measure hydraulic conductivity. The theoretical approach does not fully account for the resistances of flow through a complex 3D vascular network.

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PAR ID:
10457515
Author(s) / Creator(s):
 ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
American Journal of Botany
Volume:
107
Issue:
4
ISSN:
0002-9122
Page Range / eLocation ID:
p. 618-627
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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