Spatial distribution of mycelia of the liana (L-) biotype of the agaric Crinipellis perniciosa (Stahel) Singer in tropical forest.

A detailed investigation of the Liana biotype (L-biotype) of Crinipellis perniciosa (Stahel) Sing, was conducted in Ecuador. Basidiocarps of the L-biotype were consistently found in association with stems or debris of the liana Arrabidaea verrucosa (Standl) A. Gentry, although no symptoms associated with witches'broom disease, were observed. Debris colonized by the L-biotype were often connected via pseudosclerotial pads to living sterns of A. verrucosa. Pairings between 87 isolates obtained from basidiocarp stipe tissues or liana bark cores from three sites permitted 37 somatic compatibility groupings (SCGs) to be defined. In all cases these were found to be very restricted in geographical distribution, a situation which contrasts markedly with the distribution of SCGs in the pathogenic and non-outercrossing eocoa biotype. Mating pairings between single basidiospore isolates confirmed chat the outercrossing mechanism of the L-biotype is muitialletic and that no significant biological barriers to gene flow exist between coastal and Amazonian populations. Several lines of evidence suggested that mycelia belonging to the same SCG (= genet) were isogenic. Correlations between field observations and the distributions of both SCGs and mating type factors art- discussed in relation to patterns of dispersal, establishment and spread of this fungus.