Experiment 2 Determination of water saturation loss of plant tissue

Altation 2 Plants
Tissues
The determination of water saturation losses PrincipleAccording to physiological significance, the water conditions in plant tissues can be expressed in three different ways: natural water content, saturation water content and critical water content.1. Natural moisture content: The amount of water in a plant's tissues in a state of natural growth, called natural water content, or simply called plant moisture content.2. Saturated water content: That is, the water content of plant tissue when it absorbs water up to saturation.3. Critical water content: Plant damage occurs when the moisture content in the plant is reduced to a minimum water content level near the level of injury, which is below this level, and this minimum water content in the tissue is called critical water content.Using the above three water content values, it can be calculated that the water status of plants can be better indicated by the other two means, namely, natural saturation loss and critical saturation loss.natural saturation loss refers to the difference between the natural water content of plant tissue and the water content of fullness. Often expressed as a percentage of the saturated water content of the difference, the greater the difference, indicating that the plant water deficit is more serious.critical saturation loss refers to the difference between the saturated water content and the critical water content of the plant, which is often expressed as a percentage of the saturated water content. The higher this value, the stronger the plant's resistance to dehydration.Instrumentanalysis
balanceoven
or infrared lamp drying
metering paper sium
pliers absorbent paper operation step 1. The natural saturation loss if the natural fresh weight of plant tissue (W
f
), dry weight (W
d
) and saturated fresh weight (W
t
) can be calculated by relative moisture content method (see experiment 1), and the natural saturation loss can be calculated by pressing.According to the definition of relative water content and natural saturation loss in plant tissue, it can be seen that: natural saturation loss (%) - 1 - relative water content%Note: relative water content% method see experiment 1, so after the relative water content% can be found, you can know its natural saturation loss (%).2. Measure the critical saturation lossabout 10 pieces of plant leaves suspended indoors, so that it gradually dry for 56 hours, every 1 hour to remove two leaf weighing, and then immersed in water, to see if it can resume the expansion state, until the removed blade weighing, immersion in the water can no longer restore the expansion state (i.e. damage). At this point, the remaining blades can be taken to call their fresh weight, dried in a 100105 degrees C oven, weighing dry weight, at this time the difference between fresh weight and dry weight, that is, the critical water weight of the blade tissue (W
c
). A critical saturation loss can be reached by pressing according to the definition. The bottle says According to the measured natural saturation loss and critical saturation loss of plant tissue moisture, the degree of water demand of the plant at that time can be found.