Effect of infection by the endophytic fungus Acremonium lolii on growth and nitrogen uptake by perennial ryegrass (Lolium perenne) in flowing solution culture

摘要

Clonal tillers of a L. perenne genotype, either with or without A. lolii, were grown under natural light in flowing nutrient solutions with mineral N maintained automatically at concn of 3 or 30M NH4NO3 for 28 d. Uptake of N was monitored daily and dry matter production was assessed by sequential harvesting. The presence of endophyte had no significant effect on shoot or root biomass production at either N level, but shoot:root ratios were significantly increased by endophyte infection at both Nlevels at some harvests. All plants absorbed NH+4 preferentially to NO-3 and the ratio was not affected by endophyte infection. Also, infection did not affect total N content of plants, which was significantly more in plants at the higher than at the lower N level. It is concluded that endophyte infection had only minor effects on growth and N economy of the plant, under the conditions imposed in the experiment.