PERENNIAL RYEGRASS ENDOPHYTES IN GALICIA, NORTHWEST SPAIN

Fifty-six half-sib families of perennial ryegrass (Lolium perenne), de rived from wild populations in Galicia, were examined for the presence of perennial ryegrass endophytes; 28 were endophyte-infected (E+) and 28 were endophyte-free (E-). All families were established in spaced- plant nurseries and trial plots at two locations in Galicia, in 1992. E+ families had a significantly (P < 0.05) higher first cut, spring an d total yield than E-families at one location in the third year after planting. At this location, water deficit was about 75% higher than at the other location in all three years of study. Endophyte did not aff ect crown rust susceptibility or forage quality (crude protein, water- soluble carbohydrate and in vitro digestibility). Ergovaline alkaloid concentration in the 28 E+ families varied from 0 to 0.55 mu g/g dry m atter (DM) (mean 0.15), with 14 families containing levels of ergovali ne >0.1 mu g/g DM. Thus endophyte infection may benefit the host in dr ought-prone areas of Galicia, with an increased chance of E+ plants be ing favoured by either natural or artificial selection.