Bacteria associated with Glomus clarum spores influence mycorrhizal activity

• Published in: Soil biology & biochemistry 2003-03, Vol.35 (3), p.471-478
• Main Authors: Xavier, Lisette J.C, Germida, James J
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Arbuscular mycorrhizal fungi; Biological and medical sciences; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Inhibition; Spore associated bacteria; Stimulation; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...)
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/S0038-0717(03)00003-8

The effects of bacteria associated with arbuscular mycorrhizal fungal (AMF) spores on spore germination, growth in vitro and on the pea-AMF symbiosis were evaluated. Bacterial colonies were recovered from untreated Glomus clarum NT4 spores and NT4 spores decontaminated with 5% chloramine-T for 30, 45 and 60 min on five different media. Both G+ and G− bacteria were recovered from untreated NT4 spores, whereas only G+ bacteria were isolated from decontaminated spores. An in vitro assessment of the effect of spore-associated bacteria on clean, decontaminated NT4 spores revealed that (i) most of the bacteria isolated from untreated spores generally did not significantly alter spore function, (ii) some bacteria isolated from clean, decontaminated spores inhibited or stimulated NT4 spore germination, (iii) stimulation of spore germination occurred only when bacteria were in contact with spores, and (iv) inhibition of spore germination was the result of volatile bacterial metabolites. A stimulatory bacterial isolate, Bacillus pabuli LA3, significantly ( P