University of California

Studies on Diplodia and Diplodia-like fungi: II. Effects of nitrogen sources on growth, sporulation, and certain taxonomic characters


M. M. Satour
R. K. Webster
W. B. Hewitt

Authors Affiliations

M. M. Satour was Postgraduate Research Plant Pathologist, Department of Plant Pathology, Davis. He is now with the Department of Plant Pathology, Ministry of Agriculture, Orman, Giza, United Arab Republic; R. K. Webster was Assistant Professor of Plant Pathology and Assistant Plant Pathologist in the Experiment Station, Davis; W. B. Hewitt was Professor of Plant Pathology and Plant Pathologist in the Experiment Station, Davis.

Publication Information

Hilgardia 39(22):631-653. DOI:10.3733/hilg.v39n22p631. September 1969.

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Twenty-eight nitrogen sources (20 amino acids, 2 amide derivatives of amino acids, 4 organic nitrogen, and 2 inorganic nitrogen) were used for culture of six isolates of Diplodia natalensis and one isolate each of D. zeae, D. macrospora, Botryodiplodia theobromae, Botryosphaeria ribis, Physalospora rhodina, and a Sphaeropsis sp. Isolates were grown in synthetic liquid media and on synthetic agar media, supplemented singly with the different sources of nitrogen. Nitrogen compounds influenced mycelial growth and pigmentation, pycnidial size and orientation with respect to the substrate, presence of hairs on pycnidia, morphology of pycnidia and stromata and pycnidiospores, and exudation of the pycnidiospores. Results indicate that Diplodia and other related genera of fungi may use a wide diversity of nitrogen sources, but that the source may alter the taxonomic characters currently used to delimit this group of fungi.

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Satour M, Webster R, Hewitt W. 1969. Studies on Diplodia and Diplodia-like fungi: II. Effects of nitrogen sources on growth, sporulation, and certain taxonomic characters. Hilgardia 39(22):631-653. DOI:10.3733/hilg.v39n22p631
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