ABSTRACT
Clonality is the hallmark feature of 90% fungi. A clone is an agmetically derived descendant form of a single parent and is genetically identical at all loci with the parental genome. Consequently, it decelerates species diversity. Nevertheless, it provides a time- and resource-wise cheaper means to maintain adaptive genotypes and colonize new substrates/habitats. Given the genetic advantages of sexual reproduction and clonal multiplication, fungi harvest the benefits by accommodating both clonal and sexual phases in their life cycle. Yet, clonal multiplication is interrupted rarely once in 10,000 generations in yeasts. In Leotiomycetes and Sordariomycetes, each sexual generation depends on the participation of a mating type arising from the clonal phase. Clonal progenies are produced by costlier fragmentation through conversion of parental body or cheaper budding by development of a new progeny from stored parental resource. In fungi, evolution has proceeded from fragmenting clonals (2,843 species or 3%) in lower fungi to 97% budders in higher fungi. Hence, the former decelerates species diversity but the latter accelerates it. Another innovating approach has revealed that clonality is associated with tissue types. Clonality decreases from 90% in seven tissue typed fungi to 24% in 60 tissue typed angiosperms and zero percent in 200 tissue typed vertebrates.
