Infection by the chestnut blight fungus, Cryphonectria parasitica, can severely limit reproduction of diseased American chestnuts, Castanea dentata, by killing stems and branches with girdling cankers. In some parts of the US, the presence of a double-stranded RNA hyperparastite of the pathogen can reduce fungal growth rates. This reduction in pathogen growth allows the trees a chance to wall off cankers leading to recovery of the infected tree. We investigated the effect of recovery on the next generation by comparing seed production and weight, and seedling emergence, survival and growth among six populations of American chestnut: two healthy, two recovering, and two non-recovering. Seed production and mean seed weight varied significantly among the sites but was not related to disease status. Seed from one of the non-recovering sites was not viable. Greenhouse studies revealed a positive correlation between mean seed weight and seedling emergence, significant differences in seedling emergence among the two population types, and significant differences in final height among sites. In field experiments, three open plots and three caged plots were established at each site. Caged seedlings had significantly higher survivorship and larger size than seedlings from open plots. Overall survivorship differed among sites but was not related to disease status. Emergence in greenhouse and field studies was significantly correlated. These results indicate that environmental factors or herbivores may have a larger impact on seedling survival and growth than the disease status of the adult population.

Key words: Chestnut Blight