ES1061747U - Device for measuring the hydraulic conductivity of xylem - Google Patents

Abstract

Xylem hydraulic conductivity meter characterized in that it allows the simultaneous measurement of several samples and consists of the following elements: a) pressurization device that supplies water at a pressure between 0.01 and 0.15 bar. b) conduit for the transport of water from the pressurization device to the samples of conductive plant tissue, a mechanism that regulates the perfusion of water through the samples being included in said conduction. c) between 2 and 20 devices that contain the samples of plant conductive tissue, particularly roots, stems and petioles, said devices being located in a container that keeps them under water. d) graduated elements for measuring the volume of water perfused through each sample of plant conductive tissue individually. (Machine-translation by Google Translate, not legally binding)

Description

Hydraulic conductivity meter xylem.

Technical sector

Farming. Plant Physiology

State of the art

Since models began to be used Biology simulation, the interest in studying the transport of sap in the xylem (axial flow) of plants subject to conditions Different has been increasing.

Several authors have carried out measurements of hydraulic conductivity in different organs of the plant of numerous species, to clarify the functional significance of the resistances involved (Beckman CH, Keller JL. 1977. Vessels do end! Phytopatology 67, 954-956); Laurus nobilis (Salleo S, Nardini A, Pitt F, Lo Gullo MA. 2000. Xylem cavitation and hydraulic control of stomatal conductance in Laurel ( Laurus nobilis L.). Plant, Cell and Environment 23, 71-79; Salleo S, Lo Gullo MA, DePaoli D, Zippo M. 1996. Xylem recovery from cavitation-induced embolism in young plants of Laurus nobilis : A possible mechanism. New Phytologist 132, 47-56); Olea europaea (Salleo S, Lo Gullo MA. 1983. Water transport pathways in nodes and internodes of 1-year-old twigs of Olea Europaea L. Giornale Botanico Italiano 117, 63-74); Acer saccharum (Sperry JS, Donnelly JR, Tyree MT. 1988. Seasonal occurrence of xylem embolism in Sugar maple ( Acer saccharum ). American Journal of Botany 75, 1212-1218; Tyree MT, Yang SD. 1992. Hydraulic conductivity recovery versus water pressure in xylem of Acer saccharum, Plant Physiology 100, 669-676); Vitis vinifera Salleo S, Rosso R, Lo Gullo MA. 1982. Hydraulic architecture of Vitis vinifera L. and Populus deltoides Bartr. 1-year-old twigs: I - Hydraulic conductivity (LSC) and water potential gradients. Giornale Botanico Italiano 116, 15-27; Populus deltoides (Larson PR, Isebrands JG. 1978. Functional significance of nodal constricted zone in Populus deltoides . Canadian Journal of Botany-Revue Canadienne de Botanique 56, 801-804; Salleo S, Rosso R, Lo Gullo MA. 1982. Hydraulic architecture of Vitis vinifera L. and Populus deltoides Bartr. 1-year-old twigs: I - Hydraulic conductivity (LSC) and water potential gradients. Giornale Botanico Italiano 116, 15-27; Tyree MT, Alexander J, Machado JL. 1992. Loss of hydraulic conductivity due to water-stress in intact juveniles of Quercus rubra and Populus deltoides . Tree Physiology 10, 411-415); Thuja occidentalis (Tyree MT, Graham MED, Cooper KE, Spleens LJ. 1983. The hydraulic architecture of Thuja occidentalis, Canadian Journal of Botany-Revue Canadienne de Botanique 61, 2105-2111), etc.

The hydraulic conductivity (K_ {h}, gs <-1m MPa <-1>) reflects the efficiency of the water conduction of the xylem (Salteo S, Rosso R, Lo Gullo MA. 1982. Hydraulic architecture of Vitis vinifera L. and Populus deltoides Bartr. 1-year-old twigs: I - Hydraulic conductivity (LSC) and water potential gradients. Italian Giornale Botanico 116, 15-27), and is defined as the flow conducted through the vessels, divided by the pressure gradient. The pressure gradient is the difference in pressure between the ends of the conductive tissue segment, divided by the length of the segment. Thus, the conductivity is expressed as: K_ {h} = \ frac {Q} {\ Delta P} l where Q is the flow rate expressed in g / s, l is the length in m of the xylem in the sample and ΔP is the pressure difference in MPa.

Other authors (Salleo, S., MA Lo Gullo and F. Oliveri. 1985. Hydraulic Parameters Measured in 1-Year-Old Twigs of some Mediterranean Species with Diffuse-Porous Wood: Changes in Hydraulic Conductivity and Their Posible Functional Significance. Journal of Experimental Botany, Vol. 36, No. 162, pp. 1-11, January 1985) measured the volume of flow that passed through the internodes of Vitis vinifera , Populus deltoides and Olea europaea using a system consisting of an inlet pipette and another outlet, full of perfusion solution. The flow volume was calculated by measuring the volume displaced in both pipettes.

Sperry et al. (Sperry JS, Donnelly JR, Tyree MT. 1988. Seasonal occurrence of xylem embolism in Sugar maple ( Acer saccharum ). American Journal of Botany 75, 1212-1218) designed a system to measure conductivity in branch segments, using an induced flow by gravity. The perfusion solution was stored in a tank pressurizing compressed air from where the sample was injected or using an elevated container (gravity flow). The solution that perfused the bouquet was taken to a container located on an electronic scale. The weight variation was recorded on a computer connected to the balance. This device only allowed measuring the conductivity of a single stem segment in each measurement.

There are equipment on the market that includes microcameters capable of measuring small flows, existing several models that operate in certain ranges of flows (HFPM and HCFM-XP from Dynamax Inc., Iberfluid Instruments, Bronkhorst High-Tech, etc.). However, not always they are suitable in cases of extremely conductivities low, such as those found in olive branches and others species with conductive vessels of reduced diameter. Given the variability in the conductivity of the different organs of the different species under study, the capable equipment covering such a wide range of flows has a high cost. This cost is multiplied if the measure is required Simultaneous multiple samples.

The equipment presented in this application allows simultaneous measurement of multiple tissue samples plant conductor. It adapts to the variability present in the nature, especially in cases of very low values of conductivity. For its design and the elements that compose it it would cost less than the available equipment which together with Simultaneity of measurement results in low cost per sample analyzed.

Explanation of the invention.

The object of the present invention is a meter Xylematic hydraulic conductivity that allows measurement simultaneous of several samples and consists of the following elements:

a) pressurization device that supplies water at a pressure between 0.01 and 0.15 bar

b) conduction for the transport of water from the pressurization device towards conductive tissue samples plant, being included in said conduit a mechanism that allow to regulate the perfusion of water through the samples.

c) between 2 and 20 devices containing the samples of plant conductive tissue, particularly roots, stems and petioles, said devices being located in a vessel that keeps them underwater

d) graduated elements for measuring the volume of water pre-set through each sample of conductive tissue Vegetable individually.

It can be used as a device for pressurization a column of water between 0.1 and 1.5 m equipped with an elevated tank.

As a mechanism that allows perfusion regulation of water through the samples a system of al minus two valves that control the inlet and relief, or a three way solenoid.

The pipes are manufactured in any transparent material that allows observation of the flow through thereof, particularly polyethylene or glass and the Devices containing samples are of any material that has enough elasticity to adjust correctly and avoid leaks, particularly silicone or latex.

The meter may additionally include a high pressure device, particularly a pump, which allows raise the pressure up to 2 bars to eliminate the embolism present under natural conditions in the xylem vessels of plants. In In this case, the assembly must have at least two maneuver valves to regulate the entry of water from the water column or from the high pressure device or alternatively a three-way solenoid for the same purpose.

Brief description of the figures

Figure 1: General scheme of the meter xylem conductivity

Figure 2: Meter prototype configuration of xylem conductivity

Figure 3: Detail of pipettes and syringes to zero

Figure 4: Detail of solenoid and power supply system

Figure 5: Pressure device for treatment Disbursed

Detailed description of the invention

The object of the present invention is a device that allows to measure the hydraulic conductivity of the conductive vessels of plants. Hydraulic conductivity Xylem is the conductive capacity of the vessels that lead the sap from the root to the leaves, through trunks and branches. To obtain the conductivity of an organ of a plant, it is done pass an aqueous solution through a stem (or root) sample of known length, by applying a water column of known height and the pre-set volume is measured in a span of set time In general, the repetition of the measure to arrive at conclusions regarding the characteristics hydraulics of the material, so it is very useful to be able to Process the largest number of samples simultaneously. This reduces Labor and costs per processed sample. The equipment currently available on the market do not allow measurement Simultaneous samples and they are also expensive equipment. He equipment presented in this application allows measurement of several simultaneous samples and by components and materials necessary for its construction would cost much less than existing equipment in the market.

The meter consists of a series of tubes that conduct the water (or aqueous solution) simultaneously towards several samples of stems (or roots) of plants. The water is injected into the samples at preset pressures by means of a water column of known height. The default flow for each Sample is collected by tubes and the volume is obtained using graduated elements. Perfusion time is measured allowing obtain the flow rate (volume per unit of time). Water flow towards the samples is controlled by a series of valves that it allows the opening and closing, as well as the suppression of the water pressure in the samples, in order to stop perfusion in instant form. It has a bucket where the samples to measure and that allows the manipulation of the samples under the water to prevent air from entering tissue vessels conductor, which would cause occlusion of the vessels by embolism. The equipment is complemented by a device that allows high pressure water infusion to eliminate possible embolisms present in the conductive vessels. Measuring the flow preset, the height of the water column and the length of the samples it is possible to obtain the hydraulic conductivity (Kh) of the samples, before and after the disbursed treatment, thus obtaining the degree of embolism present in the sample. Be get the adaptation samples of different conductivity and diameter, using tubes of different diameter and elements of volume measurement according to the magnitude of the flows expected

A general scheme of the Xylem conductivity meter.

The device consists of a water column (1) which supplies water at a known pressure (h). This is led to samples of plant conductive tissue (6) by tubes (5). To the open the inlet valve (2), keeping the relief valve pressure (3) closed, water circulates through the system, perfusing the samples. Once the time has elapsed default to perform the measurement, simultaneously closes the inlet valve (2) and the relief valve (3) is opened to the effects of completely stopping the infusion of water through the samples. The volume of water infused in each sample is measured with the graduated volume measuring elements (7). The samples are placed and handled under water in an arranged bucket for this purpose (8). The maneuver valves (9) allow you to choose between work using the water column or pressurized water from the corresponding device. This one would connect in the site (10) indicated in the scheme.

In order to keep the value of the water column during measurement, a tank with a Enough volume so that your water level does not vary at length of the measurement, due to the effect of the water flow towards the samples.

The xylem conductivity meter is complements with elements that allow a treatment of disbursed with high pressure.

The high pressure device could be a pump or other element capable of raising water pressure to 1.5 at 2 bars, enough to eliminate the embolism present in natural conditions in the xylem vessels of plants. Bliss Pressurized water is stored in a reservoir that connects to the meter of conductivity at point (10) of figure 1. The device for pressure has a pressure gauge to measure the pressure reached and the required maneuver valves to adjust it to the value wanted.

The equipment allows, measuring the flow preset, the height of the water column and the length of the Samples obtain the hydraulic conductivity (Kh) of the samples. If this measurement is performed before and after the treatment of disbursed, the degree of embolism present in the sample.

Embodiment of the invention

Figure 2 shows the configuration of a prototype of the xylem conductivity meter.

The device consists of a column of water that supplies water at a known pressure measured by the piezometer (2). The elevated tank (1) fulfills the function of keep the value of the water column unchanged during measurement, since it has a sufficient capacity so that its Water level does not vary significantly throughout the measurement (due to the effect of the water flow to the samples).

Water enters the system through the inlet pipe (18), goes through the solenoid (3) and continues through the tube sample feeding (16). This is distributed and conducted to samples of plant conductive tissue (6) by multiple connections (4) and tubes (5). The samples are placed and they manipulate under water in a bucket arranged for this purpose (8). The maneuver valves (9) allow you to choose between working using the water column or with pressurized water from the boiler This is connected at the site (10) indicated in the scheme. The water flow of the system is controlled by a solenoid (3) which is operated by the electrical control panel (15) that contains a switch and a 220v-24v transformer AC. When the solenoid is activated, the passage of water between the tubes 18 and 16 and the water passes from the elevated tank to the samples of plant tissue (eg: segments of stems or roots).

0.2 ml pipettes with graduations have been used 0.002 ml, as measuring elements of the perfused volume in each sample. The pipettes are mounted on a horizontal support and can easily be exchanged for others, which may vary according to the volume that is expected to be measured depending on the material Vegetable to use.

While this prototype was implemented to measure 5 samples simultaneously (see figure 3), it is possible measure a larger number of samples, adding the tubings and corresponding pipettes. The diameters of the tubes where connect the samples will depend on the diameter of them.

It has been used for pipes pipes transparent polyethylene, while the tubes connecting the plant samples are silicone, material that has enough elasticity to adjust properly and avoid leaks.

Before starting the measurement, the entire system pipes must be filled completely with water to prevent entry of air to the conductive vessels of the plant sample.

Likewise, the pipettes of volume measurement (7), which is achieved by actuating manually the three-way valves (11) and the syringes (14).

After the default time has elapsed to perform the measurement, the solenoid is activated by dashboard switch. This action interrupts the connection between tubes 16 and 18 and simultaneously connect tube 16 with the relief tube 17, which returns excess water to the bucket (8) in order to completely stop the infusion of water to Through the samples. The volume of water infused in each Sample is measured by graduated pipettes (7).

In the implementation of this prototype, have replaced valves (2) and (3) with a three-way solenoid (see figure 4) electrically operated (24v, 4w), of the type of used in the hydraulic control of irrigation valves. He is himself connects to an electrical panel with a bipolar switch and a 220v-24v AC transformer. This ensures the simultaneity of water supply cutting operations and pressure relief. Said solenoid can be operated. manually by a switch or automatically by a timer In this prototype the solenoid is activated manually. The two maneuver valves (9) can be replaced by a single manual or operated three-way valve electrically (solenoid), also automating this function.

The xylem conductivity meter is complements with elements that allow a treatment of disbursed with high pressure. This prototype has used the following pressure device detailed in the Figure 5:

The compressed air tube (1) provides the pressure required to the boiler (2). It consists of a air chamber (3) and a chamber that is filled with water (5) separated by an elastic membrane (4). Pressurized water is connected by means of the tube (6) to the water inlet of the meter Xylem hydraulic conductivity (10 in Figure 1). For the alternating operation with high pressure or through the column of water interlock keys for the maneuvers (9 in the Figure 1). The water pressure supplied by the boiler is regulates by means of an air stopcock and a pressure gauge.

The equipment allows, measuring the flow perfused, the height of the water column and the length of the Samples obtain the hydraulic conductivity (Kh) of the samples. If this measurement is performed before and after the treatment of disbursed, the degree of embolism present in the sample.

Claims (8)

1. Xylematic hydraulic conductivity meter characterized in that it allows the simultaneous measurement of several samples and consists of the following elements: a) pressurization device that supplies water at a pressure between 0.01 and 0.15 bar b) conduction for the transport of water from the pressurization device towards conductive tissue samples plant, being included in said conduit a mechanism that allow to regulate the perfusion of water through the samples. c) between 2 and 20 devices containing the samples of plant conductive tissue, particularly roots, stems and petioles, said devices being located in a vessel that keeps them underwater d) graduated elements for measuring the volume of perfused water through each sample of conductive tissue Vegetable individually. 2. Xylem hydraulic conductivity meter according to claim 1, characterized in that the pressurization device consists of a water column of a height between 0.1 and 1.5 m provided with an elevated tank. 3. Xylematic hydraulic conductivity meter according to claims 1 and 2, characterized in that the mechanism that allows to regulate the perfusion of water through the samples is a system of at least two valves that control the inlet and the relief. 4. Xylematic hydraulic conductivity meter according to claims 1 and 2, characterized in that the mechanism that allows to regulate the perfusion of water through the samples is a three-way solenoid. 5. Xylem hydraulic conductivity meter according to claims 1-4, characterized in that the water column and the pipes are of any transparent material that allows the observation of the flow through them, particularly polyethylene or glass, and because the devices that The samples contain are of any material that has sufficient elasticity to properly adjust and prevent leaks, particularly silicone or latex. 6. Xylem hydraulic conductivity meter according to claims 1-5, characterized in that it additionally includes a high pressure device, particularly a pump, which allows the pressure to be raised up to 2 bars to eliminate the embolism present in natural conditions in the xylem vessels of the plants. 7. Xylem hydraulic conductivity meter according to claim 6, characterized in that it includes at least two maneuvering valves to regulate the entry of water from the water column or from the high pressure device. 8. Xylem hydraulic conductivity meter according to claim 6, characterized in that it includes a three-way solenoid for regulating the entry of water from the water column or from the high pressure device.