Fifty-six half-sib families of perennial ryegrass
(Lolium perenne), derived 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 and 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 affect 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 μg/g dry matter (DM)
(mean 0·15), with 14 families containing levels
of ergovaline >0·1 μg/g DM. Thus endophyte infection
may benefit the host in drought-prone areas
of Galicia, with an increased chance of E+ plants being favoured by
either natural or artificial selection.