The biochemical and genetic characterization of the Glomeromycota has been hindered by their biotrophic nature, which impedes laboratory culturing. This obstacle was eventually surpassed with the use of root cultures and, most recently, a method which applies sequencing of single nucleus from spores has also been developed to circumvent this challenge. The first mycorrhizal gene to be sequenced was the small-subunit ribosomal RNA (SSU rRNA).
