- 22. ' 



CHROMTOGRAPHIC METHODS AND THE CHLOROPLAST PIGMENTS 

 OF HIGHER PLANTS AND GREEN ALGAE 



THE COURSE OF INVESTIGATION 



Objectives 



Wien exploratory tests with chromatographic adsorption methods in- 

 dicated that the chloroplast pigments of leaves could be separated in 

 columns of powdered sugar »5 and in colxomns of magnesia » » * -'j a 

 systematic investigation of the photosynthetic pigments of various kinds 

 of plants was undertaken. The early studies in this series, carried 

 out in collaboration with Drs. Winston M, Manning and Garret Hardin » , 

 soon revealed that the chromatographic methods were effective with all 

 kinds of fat-soluble chloroplast pigments from various species of plants, 



At the beginning of these studies, it was believed that diverse 

 plants adapted to a great variety of environmental conditions might 

 yield a corresponding variety of chloroplast pigments. For a time, this 

 presumption was supported, because several new chlorophylls and many 

 new carotenoid pigments were discovered. But as the observations in- 

 creased, it became clear that the individual chloroplast pigments are 

 not distributed randomly through the plant kingdom. On the contrary, 

 certain pigments and certain combinations of pigments occur only in 

 plants that belong to taxonomioally related groups. Conversely, the 



chloroplast pigments reflect relationships among the species of the 



1 2 

 major taxonomic classes ' , 



This correlation between chloroplast pigments and plant classifi- 

 cation has now been confirmed and extended by supplementary investiga- 

 tions of the pigments of many additional plants including species from 



