Pathological Anatomy ofDactylis glomerataInfected byStagonospora arenaria
- 1 January 1982
- journal article
- research article
- Published by Scientific Societies in Phytopathology®
- Vol. 72 (1) , 146-150
- https://doi.org/10.1094/phyto-77-146
Abstract
S. arenaria penetrated guard cells subsidiary cells, and long cells of orchardgrass leaves via penetration pegs from appressoria and via hyphal wedges between cells. Most penetrations attempts at guard and subsidiary cells were successful. A few penetrations occurred through stomatal openings. Penetration attempts at long cells were usually unsuccessful. Resistance to penetration was associated with papilla formation. Papillae were more frequently formed in long cells than in guard or subsidiary cells. Penetrated epidermal cells were colonized, and then the pathogen ramified intercellularly, but sparsely, in the mesophyll. Host responses began outside the margin of hyphal growth. As the typical purple leaf spot lesions developed, epidermal nuclei migrated toward the infection center, leucoplasts of mesophyll cells enlarged and became amber, and a dark amber gel formed between mesophyll cells. Some leaf tips, leaves, or plants formed large tan lesions. Tan lesions were characterized by development of diffuse light-brown pigment, collapse of mesophyll cells, and early disintegration of plastids, chloroplasts and nuclei. In tan lesions, hyphae emerged from stomata, grew across the surface, and entered other stomata. Hyphae rarely emerged from purple lesions.This publication has 0 references indexed in Scilit: