Rhynchosporium secalis explained

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.^[1]

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.

Sources

• Index Fungorum
• USDA ARS Fungal Database

Notes and References

1. Book: Mathre , D.E. . Compendium of barley diseases . American Phytopathological Society . 1997 . 120 .