To my knowledge, greenflies (Aphidoidea) were used for phloem sap collection. But I'm not sure, whether there is some modern device being used nowadays.

Tomas maybe this paper can help you:

Estimation of canopy average mesophyll conductance

using d13C of phloem content

NEREA UBIERNA & JOHN D. MARSHALL

PCE 2011

Also dont hesitate to contact with Nerea she is really kind and helpful person

I am not an expert of trees (I have carried out some experiments on phloem sap from herbaceous crops). Anyway,

usually the collection of phloem sap from trees is carried out according to three different approach: a) phloem bleeding technique; b) phloem exudation technique; c) analysis of sugars extracted from leaves.

I suggest you to read the following paper (where the three different approaches are compared): Gessler et al. 2004 Plant Biology, 6, 721-729.

Two methods that would be applicable are using EDTA to collect phloem sap or alternatively if there is suitable aphid species you could try aphid stylectomy. The attached papers detail the methods.

Long-distance transport of L-ascorbic acid in potato

Luigi Tedone, Robert D Hancock, Salvatore Alberino, Sophie Haupt, Roberto Viola

BMC Plant Biology 2004, 4:16 (17 September 2004)

Synthesis of L-ascorbic acid in the phloem

Robert D Hancock, Diane McRae, Sophie Haupt, Roberto Viola

BMC Plant Biology 2003, 3:7 (24 November 2003)

Used the pressure chamber method that sap is come out and collect the from pipette.that is cell sap but i dont know that is pholem sap or xylem sap

Depending on the species, you can also use "bleeding" and "exsudation" techniques:

A. Gessler, H. Rennenberg, C. Keitel. 2004. Stable Isotope Composition of Organic Compounds Transported in the Phloem of European Beech - Evaluation of Different Methods of Phloem Sap Collection and Assessment of Gradients in Carbon Isotope Composition during Leaf-to-Stem Transport. Plant Biology Volume 6, Issue 6, pages 721–729.

http://onlinelibrary.wiley.com/doi/10.1055/s-2004-830350/full

hi, gattward,

some methods to collect phloem sap are

1. YAG laser beam (Collection of Pure Phloem Sap from Wheat and its Chemical Composition)

2. insect laser technique (Collection and Chemical Composition of Pure Phloem Sap from Zea mays L.)

3. Book Title: Plant Proteomics : Methods and Protocols; Series: Methods in Molecular Biology | Volume: 355 | Pub. Date: Sep-22-2006 | Page Range: 27-35

4.http://www.apsnet.org/publications/phytopathology/backissues/Documents/1982Articles/Phyto72n06_667.pdf

5. using a capillary (Effect of Potassium Supply on the Rate of Phloem Sap Exudation

and the Composition of Phloem Sap of Ricinus communis)

6. using a tiny syringe (http://5e.plantphys.net/article.php?ch=2&id=136)

7. Phloem sap collection from lettuce (Lactuca sativa L.): Chemical comparison among collection methods

8. Phloem sap collection from lettuce ( Lactuca sativa L.): Methodology and yield....

All the best...

I just noticed that the reference I gave was already there... Nevertheless, just one comment about these two methods. Bleeding method only works in species with thin bark (e.g. beech, eucalyptus), and even in this case you must do several cuttings until you get one place with enough phloem pressure to get the phloem out. The exudation method is not as clean, since you may get part of the cellular content outside the phloem, but it can work in any type of bark (we tried with oak, pine, in this case we remove the dead part of bark and keep only the "fresh" one).

cheers,

Pitter

Anyone have the full paper cited by Juan Pedro Ferrio? >>

A. Gessler, H. Rennenberg, C. Keitel. 2004. Stable Isotope Composition of Organic Compounds Transported in the Phloem of European Beech - Evaluation of Different Methods of Phloem Sap Collection and Assessment of Gradients in Carbon Isotope Composition during Leaf-to-Stem Transport. Plant Biology Volume 6, Issue 6, pages 721–729.

Thank you all, for contrubutions..

in a previous reply to this topic, Giovanni Dinelli posted it as an attachment

Dear Tomas

The two following papers of Andrew Merchant might be helpful. In addition to the Gessler, Rennenberg, Keitel 2004 paper mentioned above you might want to have a look at the two older papers from our group (Schneider et al 1996 and Gessler et al 1998) were we characterized the amino acid concentration in the phloem of European beech applying the exudation technique.

Cheers

Arthur

MERCHANT A., Wild B., Richter A., Bellot S., Adams M.A. & Dreyer E., (2011) Compound-specific differences in 13C of soluble carbohydrates in leaves and phloem of 6 month old Eucalyptus globulus (Labill). Plant Cell and Environment (in press).

MERCHANT A., Peuke A.D., Keitel C., Macfarlane C., Warren C. & Adams M.A. (2010) Phloem sap and leaf δ13C, carbohydrates and amino acid concentrations in Eucalyptus globulus change systematically according to flooding and water deficit treatment. Journal of Experimental Botany, 61, 1785-1793.

Soluble N compounds in trees exposed to high loads of N: a comparison between the roots of Norway spruce (Picea abies) and beech (Fagus sylvatica) trees grown under field conditions

Author(s): Gessler, A.; Schneider, S.; Weber, P.; et al.

Source: New Phytologist Volume: 138 Issue: 3 Pages: 385-399

Soluble N compounds in trees exposed to high loads of N: A comparison of spruce (Picea abies) and beech (Fagus sylvatica) grown under field conditions

Author(s): Schneider, S.; Gessler, A.; Weber, P.; et al.

Source: New Phytologist Volume: 134 Issue: 1 Pages: 103-114 Published: 1996

Hello Dr. Gessler, I got almost all, except the first. do you have the full paper?

Dear James

it is attached

Hi,

The EDTA exudation technique already mentioned is the most easy and general way. The aphid stylectomy technique (whether through laser or electrical cutting) is the most tedious but the most precise one may guess.

You may find a lot of references with variants from the EDTA technique (just search a combination ofd phloem x EDTA in a plant oriented db); if you need a quick (& poorly published...) ref/pdf to the insect technique, just see attached to next comment (I need to fetch the pdf... :-)/

Cheers

Here it is, a short work on the comparison of insect technique with a reference tech (not EDTA this time; lupins is unique by its pod bleeding aptitude... it has been chosen by Plant physiologists -Pate group, AUS, and others- for a lot of seminal phloem studies.

Yvan