An Optically Efficient Method for observing Single Plant Cells from Shake Cultures during Growth and Division

Abstract

THE ease with which the individual cells of callus cultures of tissues of higher plants separate from each other has led to several successful methods of growing them singly. Muir, Hildebrandt and Riker¹ grew a single crown-gall callus cell on a piece of filter paper over a large callus of the same strain. Torrey² placed many separate cells around a nurse callus; some of the former divided once or more during the subsequent two weeks. Bergmann³ made a considerable advance by utilizing a plating method for individual cells of tobacco and of bean. Of the numerous separate cells in a thin plate of agar medium, individuals were followed by time-lapse photography during their division. Optical quality of the pictures was poor due to the necessity of observation through the bottom of a Petri dish and a layer of agar. A perusal of these methods or an attempt to duplicate them makes the investigator conscious of their deficiencies; there is no possibility of observing the single cell in the first and growth is recognized only when it has formed a callus that is visible to the unaided eye, the second has most of the disadvantages of the hanging-drop, and the third suffers from poor optical quality.