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Cytology and Histology

Formation and Histopathology of Galls Induced by Ustilago esculenta in Zizania latifolia. H. C. Yang, Former graduate student, Department of Plant Pathology, Chung Hsing University; L. S. Leu, Senior Specialist, Plant Protection Center, Taiwan. Phytopathology 68:1572-1576. Accepted for publication 8 June 1978. Copyright © 1978 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-68-1572.

“Kah-peh-sung,” or “water shoot,” widely used as a vegetable in the Orient, is a gall induced by Ustilago esculenta in the stem tissues of Zizania latifolia. Histological studies and tissue isolations revealed hyphae of the fungus distributed systemically throughout the stem tissues, particularly near the apical meristem. No hyphae were found in leaf and root tissues. The hyphae grew intracellularly and intercellularly. They were present mostly in the parenchyma, but invasion of vascular bundles in young tissues was common. In the gall, the hyphae disintegrated the cells by digesting the parenchyma cell wall. Subsequently, the hyphae grew into the increased space to form a hyphal cluster. Then the hyphae in the cluster became fragmented, forming teliosporogenic hyphae and, later, teliospores. Dimensions of the teliospore sori averaged 1 × 5 to 6 mm, but the longest one measured 18 mm in length.