Resumen
- n many global regions where multiple P. infestans genotypes and multiple host species are present, some degree of host specialization has been observed, both in terms of the frequency of recurrent clonal lineages on each host, and in terms of within-lineage genotypic and phenotypic variation. For example, multiple studies in the USA have demonstrated that the US-8 lineage is common on potato, but very seldom infects tomato (Wangsomboondee et al., 2002; Danies et al., 2012; Peters et al., 2014). In studies where inoculations onto tomato and potato leaflets have been carried out, isolates are often found to be more aggressive on one host than another.