Figure 2.

Predicted progeny fitness, compatibility, mutualism effectiveness and transmission efficiency as a function of genetic diversity in allogamous species. Upper panel: progeny fitness (continuous lines, left axis) and expected level of compatibility between Neotyphodium endophytes and host plants (dashed lines, right axis) in relation to genetic distance between mating parents. Lower panel: effectiveness of the mutualistic interaction between endophytes and host plants (continuous lines, left axis) and endophyte transmission efficiency (dashed lines, right axis) in relation to the genetic distance between mating parents. White, grey and dark-grey zones represent a progressive increment in the genetic distance between mating parents (x-axis) with the corresponding intra-population, inter-population and inter-species crossings.