Neotyphodium interactions with a native grass are driven by endophyte haplotype

Abstract

We examined the effect of endophyte infection, endophyte and host plant maternal genotype on traditional growth parameters. We also measured leaf water potential, leaf rolling, and stomatal density to provide explanations for differences in biomass production and relative growth rates. Our general findings show that Neotyphodium infection, Neotyphodium haplotype and its interaction with host maternal genotype influence Arizona fescue growth, and biomass production. Endophyte haplotype and its interaction with host maternal genotype is the most critical and consistent factor in influencing growth and physiological outcomes. Endophyte-host interactions are likely to be enormously complex because of the genetic and environmental variation that exists in natural populations. The outcome of these interactions in natural grass-endophyte systems is exceedingly difficult to predict based simply on the presence or absence of the endophyte. Keywords: growth rate, haplotype, leaf rolling, plant biomass, water potential, stomatal density