No abstract

S U M M A R YIsolates from C. purpurea sclerotia occurring naturally on Phragmites communis usually sporulated vigorously on the culture medium employed, and their failure to produce alkaloid in vitro was associated with a thin white growth form. Such isolates also failed to produce sclerotia on the host plants tested. A variant having a plectenchymatic morphology in vitro and producing a thick pigmented non-sporulating growth form yielded alkaloid (up to approximately 300 ,ug/ml mainly AS-9 and A9-10 lysergic acids and chanoclavine) in surface or submerged culture and developed typical ergot sclerotia (containing 0.2-0-4 yo alkaloid, mainly ergotoxine and ergotamine) in uivo.Improved alkaloid yield in vitro was obtained from a strain reselected after passing through a parasitic phase.Aetiological aspects of the P. communis ergot are discussed. I N T R O D U C T I O NDuring a programme of research, carried out over several years, a large number of isolates from C.purpurea sclerotia collected from various host plants have been screened for the production of ergot alkaloid in vitro. This paper presents details of one of the very few alkaloid-producing strains which were found and describes comparative studies with related strains involving growth and alkaloid production in vitro and in vivo. M A T E R I A L S A N D M E T H O D SAlkaloid assay, culture media and conditions, host plant inoculation, and sclerotial germination were as previously described (Mantle, 1969). I n submerged culture the first (seed) stage flasks were incubated for 7 days at 24 "C, homogenized in an Atomix blender for 20 sec, and a 10 yo inoculum transferred to second-stage flasks.Where a third stage was used, this was inoculated with a 10 % transfer from 3-day-old second-stage flasks.Ascospore septa and nuclei were demonstrated by cotton blue and Giemsa staining, respectively. 426 P. G. MANTLEHost plant material was obtained as follows :Svalofs winter rye (short-strawed

During the summer of 1992 renal failure was diagnosed in 232 grazing cattle in 85 herds on the west coast of Norway. The salient clinical signs were depression, anorexia and melaena or fresh blood in the faeces; diarrhoea was also commonly observed. The serum concentrations of creatinine, urea, magnesium and phosphorus, and the activities of glutamate dehydrogenase, aspartate aminotransferase and creatine kinase were above normal and the serum calcium concentration was below normal. Post mortem examinations consistently revealed renal tubular necrosis. In some cases there was liver necrosis and also erosions at the base of the tongue, in the oesophagus and in the jejunum and colon. The toxicity was probably caused by the plant Narthecium ossifragum (bog asphodel).

No abstract

No abstract