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Cytology and Histology

Stem Nematode Infection of Resistant and Susceptible Cultivars of Alfalfa. B. M. Reed, Former graduate student, School of Biological Sciences, Oklahoma State University, Stillwater 74074; P. E. Richardson(2), and C. C. Russell(3). (2)Associate professor, School of Biological Sciences, Oklahoma State University, Stillwater 74074; (3)Associate professor, Department of Plant Pathology, Oklahoma State University, Stillwater 74074. Phytopathology 69:993-996. Accepted for publication 2 May 1979. Copyright 1979 The American Phytopathological Society. DOI: 10.1094/Phyto-69-993.

Chromatin content of granular cells surrounding nematode-induced cavities was increased in both resistant and susceptible cultivars of alfalfa. Increases were consistent in 8- and 12-day infections of Buffalo, a susceptible cultivar, but chromatin content of Washoe, a resistant cultivar, decreased after 8 days. Cellular disruption was progressive in both cultivars. After 16–18 days of infection, cells of Washoe were not functioning, whereas cells of Buffalo were disrupted but still functioning. Mechanical disruption of cells with a fine glass rod did not cause galling. Ligninlike reactions around wounds were stronger in Washoe than in Buffalo.