104 Plant Tissue Culture 



lows: 20 g. Ca(N0 3 ) 2 , 20 g. Na 2 S0 4 , 6.5 g. KC1, 

 8 g. KN0 3 , 1.65 g. NaH 2 P0 4 , 0.45 g. MnS0 4 , 0.15 g. 

 ZnS0 4 , 0.15 g. H 3 B0 3 , and 0.075 g. KI are dis- 

 solved together in 8 liters of distilled water. 36 

 g. of MgS0 4 are dissolved in 2 liters of distilled 

 water. The two solutions are then mixed slowly, 

 stirring constantly. Some insoluble precipitate 

 may form in the bottom of the bottle. The result- 

 ing solution is stored in a dark bottle to prevent 

 growth of algae. Ten liters of this solution are 

 sufficient to make 100 liters of nutrient, taking 100 

 ml. for each liter of nutrient required. 



The stock solution of accessory organic mate- 

 rials is made up as follows: Three grams of 

 glycine, 500 mg. of nicotinic acid, 100 mg. of 

 pyridoxine, and 100 mg. of thiamin are dissolved 

 together in 1 liter of distilled water. This is 

 pipetted into Pyrex test tubes in 10 ml. aliquots 

 and stored in the icebox at - 5° C. A liter of this 

 stock will make 1000 liters of nutrient, taking 1 



* For callus only. 



**"Gelose" — presumably means agar, but is not so specified, 

 15, 72. 



t Extract of 100 mg. dried brewer's yeast (Harris). 



t Gautheret says merely : ' ' Knop solution, i strength, ' ' 72. Since 

 there are many different formulae in use for ' ' Knop solution, ' ' this 

 is indefinite. The concentrations given above correspond to a "i 

 strength solution" of the "dilute formula" given by Palladin, 449, 

 for use with young plants. The solution for mature plants is given 

 with a concentration 5 times that of the "dilute" solution and 10 

 times the concentration given in this table. 



§ Gautheret says: "Take 10 drops of Berthelot's solution to each 

 liter of nutrient," 72. Assuming 20 drops = 1 ml., Berthelot's, 136, 

 formula would give approximately the concentrations shown in this 

 table. 



