Ergovaline Variability in <i>Acremonium</i>‐Infected Tall Fescue Due to Environment and Plant Genotype

Abstract

Competitiveness and persistence of tall fescue ( Festuca arundinacea Schreb.) is superior when infected with the endophyte, Acremonium coenophialum Morgan‐Jones &amp; Gams. Acremonium ‐derived ergopeptine alkaloids impair animal productivity, and if reduced or eliminated would improve animal performance. This study was conducted to determine: (i) environmental influence on ergovaline concentration in A. coenophialum ‐infected tall fescue genotypes, and (ii) the extent that plant genotype influences ergovaline production by the endophyte. A field experiment evaluated five endophyte‐infected tall fescue genotypes grown at three locations (environments) during 2 yr. Plant genotypes, harvested every 28 d, differed in ergovaline concentration ( P &lt; 0.05) during spring months. Rank correlations of genotypes were high among harvest dates, locations, and years. A greenhouse experiment was used to evaluate ergovaline concentration among progeny from a reciprocal cross between a high‐ and a low‐ergovaline tall fescue genotype. Parents differed in ergovaline concentration by 630 μg kg −1 but produced similar F 1 progeny means that were not different from the midparent (415 μg kg −1 ). Both F 1 populations had similar ranges for ergovaline (122‐938 μg kg −1 ). Although subject to environmental influence, ergovaline production by tall fescue— Acremonium associations was partially dependent upon plant genotype.