Hi Ali!

I believe the most used methods to measure xylem embolism are based on the reduction of hydraulic conductivity in roots, stems or leaves. As a starting point you can have a look at the John Sperry Lab webpage: (http://bioweb.biology.utah.edu/sperry/methods.html)

And I also recommend you to read the following paper:

Melcher PJ, Holbrook NM, Burns MJ, Zwieniecki MA, Cobb AR, Brodribb TJ, Choat B, Sack L. 2012. Measurement of stem xylem hydraulic conductivity in the laboratory and field. Methods in Ecology and Evolution, 3, 685-694

I hope it helps!

It surprised me,thanks a lot.

You can try with a SAP flow and dendrometer systems. This methods are very used and developed in fruit trees (vineyard and olive mainly)

Thanks Mr.Lioreda about your attention.

You're wellcome

Hi Ali,

The Xyl'em apparatus we have developed to measure xylem embolism is based on the 'Sperry' apparatus. The system is available from Bronkhorst. Visit my web site for more details: http://herve.cochard.free.fr/Techniques.htm

H Cochard

Dear Ali,

I really can recommend the XYL'EM apparatus; it is very reliable and easy to operate. However, if you first would like to test the methodology I would recommend to build the classic Sperry-apparatus yourself, it is easily done. We often use this setup in remote regions.

Furthermore, special care should be taken how the samples are handled, i.e. are the samples air cut or submersed in water, recut and connected to the system under water, and maybe even as important, what solution is used for the conductivity measurements, I would recommend degased distilled water with 10mM KCl and 1mM CaCl2.

Cheers, Bernhard

I don't have enough Facilities in my university and ... but I have to try every method like your method...anyway Thanks about your attention dear Bernhard

Abohassan, If you do not have enough facilities, or $$$, you can also measure changes in stem hydraulic conductance on the cheap. To do this, you can measure the volume flow rate through a stem or petiole sample by measuring the change in volume flow rate using: graduate pipettes (use one with the appropriate resolution per volume flow rate), a stop watch and a meter stick (a syringe helps too). Excise your samples under clean water, wrap the end of the sample with tightly pulled parafilm, attach liquid filled soft tubing that fits the stem end snugly, ensure that there are no leaks (tighten tube to stem attachment with a small cable tie to reduce leaks), attach this liquid filed tube to a water reservoir and place the reservoir above the sample (for every 1-cm change in height from the stem end to the water reservoir meniscus will increase the pressure to the stem end by 1 mbar). Attach the graduated pipette to a liquid filled syringe (see picture) so that you can adjust the meniscus in the pipette and attach this to the distal end of the stem. Using a stop watch,. measure the change in volume flow rate and time, measure the length of the segment etc to make your calculation of hydraulic conductance. To remove embolism, apply several pressure flushes following protocols described in the literature and then re-measure stem hydraulic conductance under the same conditions to calculate the percent change in stem conductance.

Here is a closeup. I use luerlock fittings. These are rather cheap and water tight and it makes connecting the tubes a lot easier.

On the water: degrassing might be important (can be done using cooking). I think adding KCl will give more stable measures over time. Also the water should be free of debris and particles. (So you might want to filter it). Degassed water will absorb gass over time again, so keep it in a closed bottle and it might be good to avoid keeping it in a fridge (since solubility of gasses is higher at cold temperature).

We used quite successfully a gravimetrical system (two water containers at different heights ) and a balance to measure water flow. (Depending on the size of your sample you need about 0.1 to 0.01 g of accuracy on the balance. )

After I degassed water, I put a tubing siphon at the bottom of the container and poured a 10 mm thick layer of pharmaceutical grade olive oil over the surface to prevent diffusion of atmospheric gases into the water below (this was the method used by Kordan, HA 1972 Journal of Applied Ecology 9: 527-533; and Kordan 1975 Annals of Botany 39:249-256 - oldies but goodies!).

Good luck.