Chestnuts bred for blight resistance depart nursery with distinct fungal rhizobiomes.

Restoration of the American chestnut (Castanea dentata) is underway using backcross breeding that confers chestnut blight disease resistance from Asian chestnuts (most often Castanea mollissima) to the susceptible host. Successful restoration will depend on blight resistance and performance of hybrid seedlings, which can be impacted by below-ground fungal communities. We compared fungal communities in roots and rhizospheres (rhizobiomes) of nursery-grown, 1-year-old chestnut seedlings from different genetic families of American chestnut, Chinese chestnut, and hybrids from backcross breeding generations as well as those present in the nursery soil.