Hatching of Meloidogyne incognita Eggs in the Neutral Carbohydrate Fraction of Root Exudates of Gnotobiotically Grown Alfalfa

R. A. Hamlen, J. R. Bloom, F. L. Lukezic


Meloidogyne incognita eggs were hatched in soil sterilized by gamma kradiation and wetted with root exudates from alfalfa plants in different stages of development and subjected to various levels of clipping. Carbohydrate components of the exudates were identified by gas chromatography-mass spectrometry. Although significant stimulation of hatch was detected in exudates of seedling and flowering plants, the practical importance of the increase is doubtful as hatch in distilled water was always greater than 50%. Hatch did not differ among exudate samples from clipped plants. Incubation of eggs in soil moistened with 10[sup-][sup7] to 10[sup-]³ M solutions of glucose did not result in increased hatching over that in distilled water. Key Words. Plant age, clipping effect, glucose effect, Medicago sativa, root-knot nematode.

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