Analysis of plant water potential pressure chamber for studying plant water potential
This Simple Electrical Sock Boarding Machine takes a very limited space. It is widely used in the small scale production unit. It's a highly recommended economic boarding machine within the quantity of 10 sets of Sock Knitting Machine. Simple Sock Boarding Machine Automatic Sock Boarding Machine,Sewing Packing Machine,Sock Forming Machine,Steam Sock Boarding Machine Shaoxing Rainbowe Machinery Co., Ltd. , http://www.rainbowe-machinery.com
The basic principle for determining the water potential of a plant using a plant water potential stress chamber is that under balanced conditions (without water flow in the plant), the water potential in the mesophyll cells is equal to that of the xylem. However, when a leaf or branch is cut from a plant, the pressure potential of the xylem juice will increase from a negative value. The value, the dialysis of the water in the xylem cells, invaded the mesophyll cells, causing the xylem sap's liquid surface to recede from the cut ends of the petioles or shoots, forming a meniscus. When sufficient pressure is exerted on the leaves or branches from the outside, the water will be forced out from the mesophyll cells, causing the meniscus to call back to the cutting end. Under this equilibrium condition, the pressure in the pressure chamber read from the pressure gauge should be equal in value to the pressure of the xylem before cutting. The equilibrium pressure measured from the plant water potential pressure chamber is the water potential of the intact leaf or branch, but The opposite sign is negative.
For ease of transportation, the components of the plant water potential pressure chamber device are connected by wire ports. As long as the assembly is tightened, no air leakage is required. When sampling and measuring, the growth condition, age, and site of the sample strain should be consistent to reduce the deviation between measurement repeats. Desert, petiole is very short, and some plant leaves are degraded. We use shoots as the material. After cutting the shoot from the plant, cut the end, pass through the clamping screw hole, pass through the rubber plug hole, then screw the clamping screw, rubber washer and sample together onto the clamping valve. The tightness of the clamping screw should be suitable. Too tight will break the young petiole or branch, too loose and will leak. This can be grasped as long as several tests are done. Finally, the cover and the main body of the pressure chamber are screwed tightly to be observed. For ease of observation, the exposed petioles or branches are cut to be as flat as the surface of the pressure chamber cover. Open the valve of the compressed nitrogen bottle, use a needle valve to adjust the amount of air intake, control the speed of the pressure rise, the speed of the pressure rise depends on the level of the plant water potential, the plant water potential is high, the pressure rises slowly, about 5 seconds An increase of 1 kgf/cm2 is appropriate; the water potential of the plant is low, and the rate of pressure rise can be slightly faster, and it takes about 5 minutes to measure it once. The speed at which the pressure rises is controlled for ease of observation. The pressure rises quickly and xylem sap emerges quickly. It is often easy to overdo it, too late to read, the pressure rises too slowly, and time is wasted.
As the pressure increases, the juice oozes out from the cut surface of the xylem, from little to large, gradually forming a spherical shape, bursting to a certain pressure, and releasing bubbles. When the first bubble is released, immediately close the needle valve and read the value on the pressure gauge. The plant's water potential pressure chamber device is well sealed, the pointer on the pressure gauge can be maintained for a certain period of time without falling, and there is enough time to record the reading. If there is a leak, the pointer will drop immediately and the reading will be faster. After the sample is measured, open the deflation valve and release the gas. The pointer on the pressure gauge returns to 0 to open the pressure chamber cover and measure the next sample according to the above method.