Natural auxins 



Figure 25. Histogram showing the 

 biological activity of a chromatogram 

 run in hopropanol + ammonia-]- water 

 (80; 10; 10) of an extract of 300 mg 

 {fresh weight) of apical meristems of 

 Adiatum pedatum, assayed with oat 

 first internodes. 



Figure 24. Histograms showing the biological 

 activity of chromatograms of tissue culture extracts 

 run in he x ane -\- water and assayed with first 

 internode sections. PTN = extract with 2/3 

 ether+ 1/3 ethanol (3-5 hours at 0°C) of 4-5 g 

 (fresh weight) of Parthenocissus tricuspidata 

 normal tissue grown in vitro for 5 months on 

 a medium containing sucrose, mineral salts, and 

 lAA (50 yjL). PTH = extract with 2/3 

 ether + 1/3 ethanol (2 hours at 0°C) of A g 

 (fresh weight) of Parthenocissus tricuspidata 



habituated' tissue, grown for 2 months on a 

 medium containing ordy sucrose and mineral salts. 

 PTG = extract with IjZ etker+lj'i ethanol 



(2 hours at O'C) of 3-75 g {fresh weight of 

 Parthenocissus tricuspidata crown-gall tissue 

 grown for three months on a medium containing 

 only sucrose and mineral salts. 



internodes. Figure 25 gives the results which demonstrate well that a good 

 picture of the auxins present in plant tissues can be obtained with a crude 

 extract, and with as little as 300 mg fresh weight of material. 



THE CHEMICAL IDENTIFICATION OF AUXINS ON THE CHROMATOGRAMS 



From the results presented so far, it is clear that one can detect numerous 

 biologically active substances on the chromatograms of plant extracts. This, 

 however, does not conclude our task. We want to know also the chemical 



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