OOGENESIS IN SEVERAL FREE-LIVING AND PLANT-PARASITIC NEMATODES

Abstract

Two techniques were used in preparation of nematode material for the present study of nematode chromosomes. These were (a) the squash method (using propionic-orcein in staining) and (b) the paraffin embedding method. A new technique, using 2% agar blocks, was employed in the handling of small nematodes. Oogenesis in a cyst-forming nematode (Heterodera sp.), two root-knot nematodes (Meloidogyne incognita (Kofoid and White, 1919) Chitwood, 1949, and Meloidogyne hapla Chitwood, 1949), and a free-living nematode (Diplogaster sp.), was studied using slide material prepared by the squash method. Chromosome numbers were determined for the most part in the primary oocyte. It is suggested that chromosome numbers may eventually be of some use in the determination of plant-parasitic nematode species.