SEXUAL-BEHAVIOR OF ARMILLARIA-HEIMII AND ARMILLARIA-MELLEA ISOLATES FROM AFRICA

Thirty isolates of Armillaria heimii from western, eastern and souther n Africa were cultured for fruit body production in the laboratory. Mo st isolates fruited easily. Investigation of single-spore progenies re vealed that all the isolates do not have the same sexual behaviour: so me are heterothallic and unifactorial while others are homothallic. Tw o African isolates belonging to the species Armillaria mellea also app eared homothallic. Unifactorial heterothallism has not previously been described in Armillaria species. Homothallic behaviour has been repor ted only in a rare European species Armillaria ectypa and in the Japan ese subspecies Armillaria mellea ssp. nipponica.