Abundance and diversity of Schizophyllum commune spore clouds in the Caribbean detected by selective sampling

Selective spore trapping and molecular genotyping methods were employed to examine potential long-distance gene now among Caribbean populations of the common mushroom Schizophyllum commune. Spore-trap samples from five locati ons were analysed using restriction fragment polymorphisms of five enzymati cally amplified gene regions. Successful trappings suggested S. commune spo res to be abundant in the air, with an estimated sedimentation rate of appr oximate to 18 spores/m(2)/h. High levels of genetic diversity characterized the spore-trap samples, with as many as 12 alleles observed at a single lo cus (chitin synthase) over all samples. In addition, spore-trap samples sho wed significant among sample heterogeneity including geographical populatio n substructure. The ribosomal DNA (rDNA) intergenic spacer displayed the gr eatest allele frequency differences among samples, clearly separating the s amples into those possessing only a South American-type allele and those se gregating for both North and South American-type alleles. The molecular var iation provided no clear evidence for dispersal over large, aquatic barrier s within the Caribbean region, and instead suggested that spore-trapping ex periments are primarily reflective of the local, established population.