Claroideoglomeraceae - C. Walker & Schüßler

Glomoid Spore

Species in this mono generic family form typical glomoid spores that usually consist of a three-layered spore wall: a sloughing outer layer that stains dextrinoid in Melzer’s reagent, a middle laminate layer, and a thin inner layer that bridges the lumen of the subtending hypha and thus forming a “septum.” Species are differentiated by spore size and color of the middle laminate layer. Typical arbuscular mycorrhizas are formed, with vesicle formation highly varied depending on environment.

Species in this family were separated from previous inclusion in Glomus because they grouped in a distinct clade based on SSU sequences. LSU and beta-tubulin genes provide congruent support. However, rDNA-based species-level resolution is not as clear-cut as in other glomoid clades, possibly because of the persistence of ancestral polymorphisms in gene repeats (van Kuren et al., 2012).

References

• Schüßler, A and C. Walker C. 2010. The _Glomeromycota: a species list with new families._ Electronic copy available online at Glomeromycota PHYLOGENY.


• VanKuren, N. W., H. C. den Bakker, J. B. Morton, and T. Pawlowska. 2012. Ribosomal RNA gene diversity, effective population size, and evolutionary longevity in asexual Glomeromycota. Evolution doi:10.1111/j.1558-5646.2012.01747.x.