Determine Stomatal Number and Stomatal Index.

 Experiment

Determination stomatal number and stomatal index- pharmacognosy practical.

Object:

To determine stomatal number and stomatal index.

Reference:

1) Kokate C.K., Purohit A.P, "Pharmacognosy" Nirali Prakashan Pune, 42th edition 2008 pp: 6.4-6.5.

2) Khandelwal K.R. "Practical Pharmacognosy" Nirali Prakashan,Pune 19 edition, Reprint 2008 pp- 146.

Requirements:

Microscope, glass slide,cover slip, glycerin, forcep, cutter and plant leaf.

Theory:

Stomatal Number:

Stomatal number is defined as the average number of stomata per sq.mm of epidermis of the leaf. The actual number of the estimate of per sq.mm may very for the leaves of the some plants grown in different environment or the different climatic conditions. It is however soon that the ratio of the number of stomata to the total number of epidermal cell in a given area epidermis is fairly constant for any age of plant under different climatic condition.

Stomatal Index:

Stomatal index is the percentage of which the number of stomata from to the total number sales is stomata been counted as one cell index can be calculated by using following equation

S.I =      S       ×100

 E+S

Where,  S= No. of stomata per unit area.

            E= no.  of epidermal cell present in the same area.

Procedure:

1. At first take (any plants) leaf, cut its upper and lower epidermis.
2. Then put it on the glass slide with the help of forcep 
3. After that add 2-3 drops of glycerin and cover it with glass cover slip.
4. Then observe it under the microscope and count the stomata on upper and lower layers.

Calculation:

For upper layer :

Stomata per unit area (S) =  X.   

No. of  epidermal cells in same unit area (E) =  y 

Here X and Y are the number 1,2,3,4.....

Formula  S.I =      S       ×100 

                                E+S

Where,  S= No. of stomata per unit area.

            E= no.  of epidermal cell present in the same area.

#Now put the value in formala and get the answer.

For lower layer: 

Calucated in the same way as above.

Result:

The no. of stomata found in Upper layer ______

And the stomatal index is _____%

Where as the no. of stomata found in lower layer is_____ and stomatal index is_______%