Plant life cycle
Plant life cycle (i.e., annual, biennial, and perennial) can influence
susceptibility of plants to pathogens
(Clay 1995). Certain
pathogens are more likely to infect and persist in perennial than annual
plant populations because annual plants do not have overlapping
generations, so this advantage of annual plant species is specific to
horizontally transmitted pathogens. Whereas, pathogens that depend on
alternative mechanisms to persist such as vertical transmission (i.e.,
transmission from seeds to mature plants, instead of horizontal
transmission between plants), free-living infective stages, and
alternative hosts would persist among annual plant species
(Thrall et al.1993; Borer et al. 2007). To our knowledge, no studies have
determined the prevalence of pathogens in plant species with different
life-cycles.