Alkaloid content in Neotyphodium-infected seeds of perennial ryegrass wild populations from the North of Spain

摘要

The alkaloid content (lolitrem B and ergovaline) in Neotypohodium-infected seeds of 21 perennial ryegrass (Lolium perenne L.) wild populations from the North of Spain was analysed. The infection level in perennial ryegrass was low to moderate (average = 40.1 percent), ranging from 8 to 80 percent. In most of the populations (62 percent) the infection level was below 50 percent. In perennial ryegrass seeds, the average lolitrem B content was 1.1 ppm, ranging from 0.0 to 7.1 ppm and the average ergovaline content was 13.5 ppm, ranging from 1.0 to 36.2 ppm. The relationships between endophyte infection and alkaloid content were studied using Spearman's correlations. Significant correlations were found between endophyte infection and ergovaline (r = 0.59 at p < 0.01). The highest concentrations of lolitrem B and ergovaline were considered high enough to induce ryegrass staggers and fescue toxicosis but the species diversity in natural pastures of northern Spain can probably prevent the disorders. In pastures abundant in natural endophyte-infected perennial ryegrass, grazing seed heads should be avoided, because the highest levels of alkaloids are actually found in seeds.