TPQK-1000 Plant Leaf Porometer

Stoma is the main outlet of water vapor from the internal to the external during transpiration, and also the channel for photosynthesis and respiration to exchange gas with the outside, thus affecting the processes of transpiration, photosynthesis and respiration. The closing and opening of stoma are controlled by guard cells. The wall thickness of guard cells is different, and cellulose microfibrils are connected with the cell wall, which leads to stomatal opening. When guard cells swelled with water, the thinner outer wall was easy to elongate and expand outward, but microfibrils were difficult to elongate, so stoma opened and transpiration was strengthened. Stoma control the entry and exit of carbon dioxide, so it is related to photosynthesis and respiration. Therefore, the measurement of transpiration rate and stomatal conductance is of great significance to agricultural research, teaching, horticulture research and forestry research.