Home • Absidia padenii NRRL 2977 v1.0
Figure 1) Fusiform chlamydospores of A. padenii. Figure 2) deliquesced sporangial wall of A. padenii. Images by Kerry O'Donnell.
Figure 1) Fusiform chlamydospores of A. padenii. Figure 2) deliquesced sporangial wall of A. padenii. Images by Kerry O'Donnell.

Absidia padenii NRRL 2977 (= CBS 172.67 = RSA 1211) was isolated originally from a pea plant exhibiting signs of root rot by J. Paden, Prosser, Washington in 1962.  This isolate was originally placed in the newly described monotypic genus, Chlamydoabsidia (Hesseltine & Ellis 1966) within the Mucoraceae (Mucorales).  However, two years later Mil’ko (1968) reclassified it in Absidia as A. padenii.  The latter classification is supported by molecular phylogenetic data, which indicates this species is deeply nested within Absidia.  This genus is currently classified in the newly circumscribed mucoralean family Cunninghamellaceae (Walters et al. 2013).  Absidia padenii produces distinctive pigmented, fusiform chlamydospores in the aerial mycelium (Fig. 1) and columellate, multispored sporangia in which the sporangial wall deliquesces at maturity (Fig. 2).  Isolate NRRL 2977 does not reproduce sexually and is presumed to be heterothallic.  The whole-genome of Absidia padenii should help elucidate evolution within the Cunninghamellaceae of the Mucorales and other early diverging fungi.

References

Hesseltine CW & Ellis JJ. 1966. Species of Absidia with ovoid sporangiospores. I. Mycologia 58:761–785.
Mil’ko AA. 1968. De nomenclatura mucoralium nonnullorum clavibus diagnosticis specierum Circinellae, Thamnidii et Kickxellae adjectis. Nov. Syst. Plant. non Vascul. 1968:79–88.
Walther G, Pawłowska J, Alastruey-Izquierdo A, Wrzosek M, Rodriguez-Tudela JL, et al. 2013. DNA barcoding in Mucorales: an inventory of biodiversity. Persoonia 30:11–47.