RECEPTIVITE DE CULTIVARS DE CEREALES DE PRINTEMPS A LA CONTAMINATION DES GRAINES SUR INFLORESCENCE PAR LES Fusarium SPP.

Abstract

The incidence of Fusarium spp. in seeds was determined in 21 samples of each of 34 lines of spring cereals, namely 13 lines of common wheat (Triticum aestivum), 13 lines of oats (Avena sativa) and 8 lines of barley (Hordeum vulgare), harvested in Québec in 1978. The number of surface-sterilized seeds displaying Fusarium on a selective agar medium was used as a basis of determination. Average infection in wheat cultivars was 11%, as against 15% in oats and in barley. Significant differences were found among cultivars in all three cereals, being the most marked in wheat and the least marked in barley. There is a significant negative correlation between plant height and seed infection of the lines involved in the three species: r = −0,61 (wheat), −0,66 (oats), −0,90 (barley). Life span of the crop is also significantly related to infection of wheat lines (r = +0,76). Moreover, lines of hard wheat (Neepawa, BW-20, Sinton) are all less infected than lines of soft wheat, just as lines of malting barley (OAC 21, Conquest, Bonanza) are all less infected than feed barley types.