A Unisexual Male Culture of Chalara Quercina

Abstract

In crosses between isolates from Minnesota and West Virginia, culture 805 failed to act as female in repeated trials. When this culture having light mycelium was crossed with a bisexual culture with dark mycelium, the 23 F₁ single ascospore cultures segregated into light male and dark bisexuals. The compatibility factors separated independently of sex or color of mycelium. Other isolates have shown this apparent inability to act as female. It is not yet known Whether unisexual male mutants occur in nature.