the Water mode of plants. Measurement of water potential of runaways of plants

you are: the Water mode of plants

Existence of a tension of water in ksileme yields to us a fast method of definition of water potential of runaways, suitable for field researches. At pererezke a stalk the tension is eliminated and f ksilemy, containing almost pure water, falls almost to zero. thereof the cages of runaway which were earlier in balance with ksilemoj in which there was a tension, have an opportunity to absorb an additional quantity of water. While they soak up this water from ksilemy, the solution filling vessels ksilemy, is a little involved inside, receding from cut edge. the cut off runaway place in special thick-walled germetizirovannyj the container - a bomb for measurement of negative pressure, and fix it here so that the cut place was outside. To a bomb attach a cylinder with the compressed nitrogen and start to raise gradually pressure in it. This external pressure enclosed to runaway raises potential of pressure of cages of runaway owing to what water from them is squeezed out back in ksilemu. Watching in a microscope this process, try to seize the opportunity when the solution filling vessels ksilemy, will reach cut places. It is considered that pressure in a bomb during this moment equally (but it is opposite on a sign) to a tension existing in ksileme before the stalk has been cut. If vessels ksilemy have been filled by absolutely pure water the tension in them would be in accuracy to equally water potential of cages of runaway. (actually in ksilemnom juice there are dissolved salts, but their concentration is very low, and it is accordingly very insignificant considering it is the amendment.) the described method gives the chance to define quickly the water status of plants in the field so it is useful both to ecologists, and for agriculturists.