Abstract
A description is provided for Leptosphaeria nodorum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Triticum spp. Also on many other genera in the Gramineae including Agropyron, Cinna, Dactylis, Deschampsia, Elymus, Festuca, Glyceria, Hordeum, Hystrix, Lepturus, Melica, Poa, Psamma, Secale, Stipa (Sprague, 1950). DISEASE: Glume blotch of wheat. Causes discoloured to brown lesions on glumes, culms and leaves. Leaf lesions are 1 cm long, elongated, elliptical, golden brown, surrounded by a diffuse, lighter margin becoming darker and bearing pycnidia. Similar brown lesions occur on glumes where they spread from the apices downwards, and bear pycnidia and perithecia. Perithecia are also formed on dead glumes and culms. The heads of wheat may become blackened, producing shrivelled kernels of abnormal structure. Germinating seedlings may also be attacked with subsequent loss of vigour. GEOGRAPHICAL DISTRIBUTION: Africa (Ethiopia, Kenya, Malawi, Morocco, Rhodesia, South Africa, Tanzania, Uganda, Zambia); Asia (China, Formosa (Taiwan), India, Japan, U.S.S.R.); Australasia (Australia, New Zealand); Europe (Austria, Belgium, Bulgaria, Czechoslovakia, Denmark, France, Germany, Great Britain, Greece, Ireland, Italy, Latvia, Netherlands, Norway, Poland, Portugal, Rumania, Spain, Sweden, Switzerland, U.S.S.R., Yugoslavia); North America (Canada, U.S.A.); South America (Argentina, Bolivia, Brazil, Uruguay). (CMI Map 283, ed. 2, 1954; Herb IMI.) TRANSMISSION: Frequently seed-borne (Noble et al., 1958; Hewett, 1965), persisting in a viable condition in seed up to 7 yr. in Canada (31: 596). Also surviving in wheat stubble and crop residues and after 1 yr. in straw kept in dry storage (43, 4g, 2589). Conidia have remained viable in pycnidia after 18 months in the open (Weber, 1922).
Étude des conditions optimales permettant la pycniogenèse de Phaeosphaeria (Leptosphaeria) nodorum (Müll) Hedj agent de la septoriose du blé
