Nuclear changes induced by the nematode Longidorus elongatus in root-tips of ryegrass, Lolium perenne.

The plant ectoparasitic nematode Longidorus elongatus induces distinct changes in the root-tip nuclei of perennial ryegrass (Lolium perenne L.). There was an initial shift in DNA content into the 4C category, followed by further increases with values intermediate between 8C and 16C present after eight days. Nuclear size was reduced after six days due to increased nuclear division during hyperplasia. Nuclear DNA content and size decreased in galls older than eight days as a result of nuclear disintegration induced by L. elongatus. In cells near to the feeding site, nuclei became split into several, small globules. In more distant nuclei DNA-containing material became dispersed throughout the cytoplasm. In the oldest galls, cells were largely devoid of nuclei.