Intraspecific ITS Polymorphism inScutellospora castanea(Glomales, Zygomycota) Is Structured within Multinucleate Spores

Identification and Isolation of Two Ascomycete Fungi from Spores of the Arbuscular Mycorrhizal Fungus Scutellospora castanea

“…The fact that the isolated Leptosphaeria sp. contained sequences very closely matching those of T1 and T3 (9,20) makes it very likely that the previously reported sequences T1 and T3 also came from a fungus in the Leptosphaeria genus living inside healthy S. castanea spores rather than as contaminants on the surface of the spores as previously suggested (24). The further observation of fungal hyphae inside S. castanea spores with a morphology similar to that of the isolated Leptosphaeria sp.…”

“…However, at present, very few genes other than rRNA genes have been studied in these fungi. Several studies have shown that genetic diversity of the internal transcribed spacer (ITS) exists among and within single spores (9,16,22). Six different ITS1-5.8S-ITS2 types (T1 to T6) from S. castanea were reported (8).…”

“…Six different ITS1-5.8S-ITS2 types (T1 to T6) from S. castanea were reported (8). The 5.8S sequences published by Hijri et al (9) were subsequently used in a phylogenetic analysis of Glomales and other fungi (20). This analysis showed that the highly divergent sequences T1, T3, T5, and T6 clustered within the ascomycetes (with Phoma-Leptosphaeria as the closest relatives to T1 and T3).…”

Detection and Identification of Bacterial Endosymbionts in Arbuscular Mycorrhizal Fungi Belonging to the Family Gigasporaceae

“…The success of AM fungi in evolution is mainly due to their central role in the capture of nutrients from the soil (29). Despite recent breakthroughs in our knowledge of the molecular basis of plant-fungus interactions (1, 12), many aspects of the biology of AM fungi, particularly their genomes, are still obscure due to their biotrophic status, their multinuclear condition, and an unexpected level of genetic variability (13,15,17).…”

“…The success of AM fungi in evolution is mainly due to their central role in the capture of nutrients from the soil (29). Despite recent breakthroughs in our knowledge of the molecular basis of plant-fungus interactions (1, 12), many aspects of the biology of AM fungi, particularly their genomes, are still obscure due to their biotrophic status, their multinuclear condition, and an unexpected level of genetic variability (13,15,17).A further level of complexity is due to the presence of cytoplasmic structures initially termed bacterium-like organisms (BLOs) that have been found in different AM fungal species (Glomus calidonium, Acaulospora laevis, Gigaspora margarita) by electron microscopy (7,18,21,27). A combined morphological and molecular approach has shown that BLOs in the spores of G. margarita (isolate BEG 34) are true bacteria (6).…”