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Home → Publications → American Chestnut Proceedings → 1982 → Summary of Relationships Among Swollen Superficial Cankers, Survival of American Chestnut Trees, and Hypovirulence in Endothia Parasitica at Southeastern Forest Experiment Station

Summary of Relationships Among Swollen Superficial Cankers, Survival of American Chestnut Trees, and Hypovirulence in Endothia Parasitica at Southeastern Forest Experiment Station

ABSTRACT.--Sixty-seven blight cankers on American and European chestnut trees yielded Endothia parasitica with hypovirulence (H) from 3 percent of the 1,240 isolates. One isolated American chestnut from near Bonair, Tennessee, yielded 28 of the 37 H isolates. American chestnut sprouts were killed 15 months after inoculation by virulent isolates but usually healed over after inoculations with H isolates. Bark patches from swollen superficial (SS)cankers used to inoculate American chestnuts have caused normal, lethal cankers 79 percent of the time after two growing seasons. Single compatible H isolates, combinations of H isolates including a compatible one, and 28 randomly selected H isolates when applied to wounded cankers have enhanced healing and prolonged tree survival in comparison to wounded check trees. Nonwounded cankers sprayed with conidia from compatible H isolates are healing as well as wounded cankers painted with mycelium in agar. Wounded and nonwounded check trees have 86 percent mortality in contrast to 29 percentt ree mortality in the H treatments.


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Author(s): E. George Kuhlman

Publication: American Chestnut Proceedings - 1982