Natural auxins 



extract. Indications of the presence of growth inhibitors can be seen, 

 especially in the ether extract. When the amount of tissue extracted with 

 ether is increased, the inhibitory regions around Rf 0-5 and Rf 0-9 become 

 very marked. Thus, this first example shows that different extracting 

 solvents may give different auxin pictures, both quantitatively and qualita- 

 tive'ly. As far as quantities are concerned, with the tissue used in this 



3-5 - 



2-0- 



'111 



f-5 



2-5- 



2-0 



1-5 - 



Acetone i 



^1 

 Ether 



^It^i 



li 



rtil 



I ! 



I 



I 



Ethyl acetate i 



111' 



Figure 1. Histograms showing the biological 

 activity of substances extracted ivith different 

 solvents from tomato ovary tissues. The unripe 

 tomato fruits (male sterile mutant of the var. 

 John Baer) were harvested 20 days after hand- 

 pollination and lyophilized. 100 mg {dry 

 weight) of the lyophilized powder were 

 extracted for 3 hours at C with the indicated 

 solvent. The crude extracts were concentrated 

 under reduced pressure and chromatographed 

 in KOpropanol +2?>°o ammonia + water (80; 

 10; 10) {vjv). When the solvent front had 

 travelled 20 cm past the initial spot, the paper 

 strips ( Whatman No. 1 paper) were air-dried 

 and cut into twenty 1 cm segments. Each of 

 these paper segments was incubated with 0-5 c.c. 

 of solution and ten oat coleoptile sections. The 

 elongation of these sections after about 20 hours 

 is plotted along the orditmte axis of the diagrams. 

 The position of the paper segment on the 

 original chromatogram is plotted in Rf units 

 along the other axis. 



particular instance, ethyl acetate and especially methanol were better than 

 ether. 



A second example is taken from another fruit, the bean. Lyophilized bean 

 seeds, dissected out of the pods about 8 days after pollination, were extracted 

 for 5 hours at 0°C in the dark with 10 c.c. each of absolute methanol, 

 absolute ethanol, or anhydrous ethyl acetate. The aliquot extracted with 

 ethyl acetate was washed at the end with absolute ethanol and the two 

 extracts combined. The chromatograms were developed in the same solvent 



