Histopathology of Ditylenchus destructor on Peanut.

The time and mode of entry, and development of Ditylenchus destructor in peanut were studied in field and greenhouse experiments. Few nematodes were present in the cortex of the roots. At 90-120 days after planting, D. destructor was observed in the exocarp at the base of the pod near the point of connection with the peg. The peg was invaded from this primary infection site. The endocarp of the hull was usually penetrated through openings at the base of the mesocarp and sometimes at the pod apex. Numerous D. destructor were present in the testa and the vascular bundles. Nematodes were found in the embryo but not in the cotyledons. The histopathology of D. destructor closely resembles that of the peanut testa nematode, Aphelenchoides arachidis Bos.