Rhynchosporium secalis is an ascomycete fungus that is the causal agent of barley and rye scald.
Morphology No sexual stage is known. The mycelium is hyaline to light gray and develops sparsely as a compact stroma under the cuticle of the host plant. Condia (2-4 x 12-20 μm) are borne sessilely on cells of the fertile stroma. They are hyaline, 1-septate, and cylindric to ovate, mostly with a short apical beak. Microconida have been reported, but their function is unknown. They are exuded from flasklike mycelial branches.
Host species Agropyron dasystachyum, A. desertorum, A. elmeri, A. intermedium, A. riparium, A. scabriglume, A. semicostatum, A. subsecundum, A. trachycaulum, A. trachycaulum var. trachycaulum, A. trachycaulum var. unilaterale Agrostis gigantea, A. stolonifera, A. tenuis Alopecurus geniculatus, A. pratensis Bouteloua gracilis, B. hirsuta Bromus aleutensis, B. carinatus, B. ciliatus, B. frondosus, B. inermis, B. pumpellianus, B. secalinus, B. vulgaris Calamagrostis arundinacea, C. epigejos Chrysopogon gryllus Critesion murinum Cynodon dactylon Dactylis glomerata Danthonia sp. Deschampsia cespitosa Elymus angustus, E. canadensis, E. chinensis, E. glaucus, E. junceus, E. repens, E. virginicus Festuca pratensis, F. rubra Hordeum aegiceras, H. brachyantherum, H. distichon, H. hexastichon, H. jubatum, H. leporinum, H. murinum, H. vulgare, H. vulgare var. nudum, H. vulgare var. trifurcatum Leymus condensatus, L. innovatus, L. triticoides Lolium multiflorum, L. perenne, L. rigidum Microlaena stipoides Panicum sp. Phalaris arundinacea Phleum pratense Poa annua, P. eminens, P. pratensis Quercus chrysolepis Roegneria sp. Secale cereale, S. montanum × Triticosecale sp.
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