Alkaloid production and chinch bug resistance in endophyte-inoculated chewings and strong creeping red fescues

Four Chewings fescue and two strong creeping red fescue selections that had been artificially inoculated and stably maintained with four different end ophytes were evaluated in feeding trials with chinch bugs (Blissus leucopte rus hirtus). Significant differences in survival were found between the end ophyte-inoculated plants and their endophyte-free counterparts. After seven days, 54.2% of chinch bugs were alive on endophyte-free tillers versus onl y 7.4% of chinch bugs fed tillers from endophyte-inoculated plants. Some di fferences were also found among the various plant-endophyte combinations. I n Petri dish preference trials, chinch bugs showed a preference for the CA endophyte (obtained from a Chewings fescue) over the RC endophyte (obtained from a strong creeping red fescue) in Chewings fescue selection C1117. Onl y the inoculated plants produced erogvaline, peramine, and lolitrem B; more over, significant differences were found among the plant-endophyte combinat ions in the levels of these alkaloids. The Chewings selections C1117 and C1 090 produced more ergovaline, and C1090 more lolitrem B, than other plants, regardless of endophyte source. In the presence of the RC endophyte, more ergovaline and lolitrem B was produced than in the presence of the CA endop hyte regardless of plant genotype. Both host plant and endophyte, therefore , contributed factors that determined alkaloid production. No significant c orrelations between chinch bug survival and alkaloid levels were found, how ever, and overall, no one plant genotype or endophyte source proved to be s ignificantly more toxic than another to chinch bugs. Nevertheless, the resu lts clearly demonstrated that artificial inoculations of endophyte-free fes cue genotypes can produce plants with increased toxicity to chinch bugs.