Mating and Fruiting Studies of Auricularia Delicata and A. Fuscosuccinea

ABSTRACT

Single-spore isolates were obtained from three collections of Auricularia delicata from the People's Republic of China and five collections of A. fuscosuccinea: one each from the Northern Marianas Islands, Ryukyu Islands and Florida, and two from Brazil. A typical bifactorial pattern was observed in self-crosses of one of the A. delicata stocks and in the A. fuscosuccinea stocks from the Northern Marianas Islands and Florida. In these stocks, nuclear migration was not observed in A≠B≠ crosses and false-clamped mycelia derived from A≠B= crosses were stable. Mating patterns could not be determined in the remaining five stocks. Where reactions occurred, few true clamps and mostly false clamps were observed. The reason for the reduced ability or inability of these stocks to cross is believed to be due to the length of time that the basidiocarps had been dried prior to obtaining spore deposits. All combinations of interstock crosses of A. delicata, and the Northern Marianas Islands x Ryukyu Islands and Brazil x Brazil crosses of A. fuscosuccinea were compatible and typical basidiocarps developed from dikaryons. The Florida stock was intersterile with all other stocks, and those from the Northern Marianas Islands and Ryukyu Islands were intersterile with those from Brazil. Intersterile reactions were characterized by a zone of aversion, at the contact zone, where the monokaryons grew together. Fruiting studies indicate that the presence/absence of the medulla in Auricularia and the merulioid to porose-reticulate hymenium in A. delicata are inherent characteristics and not environmental modifications. However, the basidiocarp color was more variable in A. fuscosuccinea than described in the literature.

Key Words:

• Auricularia
• bifactorial incompatibility
• fruiting
• heterobasidiomycetes
• mating