Ultrastructural Cytochemistry of Secretory Granules of Esophageal Glands of Meloidogyne incognita

C. A. Sundermann, R. S. Hussey


Ultrastructural cytochemical tests for several enzymes, proteins, carbohydrates, and nucleic acids were conducted on secretory granules oÐ dorsal and subventral esophageal glands of preparasitic second-stage juveniles and the dorsal gland of adult females of Meloidogyne incognita. Secretory granules in the subventral glands of juveniles stained positive for acid phosphatase. Peroxidase, DNase, RNase, cellulase, and nucleic acids were not detected in these granules. Secretory granules in the dorsal gland of adult females stained positive for peroxidase (pH 7.6) in 50% of the tests, Acid phosphatase,[beta]-glucuronidase, DNase, RNase, polyphenoloxidase, cellulase, and carbohydrates were not detected in dorsal gland granules in adult females. Positive staining with cobalt thiocyanate, a stain for amino groups of basic proteins, occurred in secretory granules in the dorsal gland, ribosomes, and chromatin in adult females. Ribosomes, nuclei, and secretory granules of the dorsal gland of adult females intensely stained when incubated in three reagents specific for nucleic acid. Key words: cytochemistry, Meloidogyne incognita, secretory granule, esophageal gland, enzyme, root-knot nematode, electron microscopy.

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