The DNA Content of Nuclei in Pea Root Nodules

Abstract

The Occurrence of nuclei and different DNA classes has been investigated in sections of pea root nodules using the techniques of Feulgen photometry. Four distinct classes, 2C, 4C, 8C, and 16C, were observed. When the positions of nuclei in the four classes were poltted a definite distribution in the nodule section was observed. An outer cortex of 2C Cells and an inner cortex of 4C cells, both uninfected, enclose a central infected zone containing cells with 8C and 16C nuclei. The development of this particular structure from the nodule meristem is discussed.