ARBUSCULAR MYCORRHIZA PROTECT AN ANNUAL GRASS FROM ROOT PATHOGENIC FUNGI IN THE FIELD

Citation
Kk. Newsham et al., ARBUSCULAR MYCORRHIZA PROTECT AN ANNUAL GRASS FROM ROOT PATHOGENIC FUNGI IN THE FIELD, Journal of Ecology, 83(6), 1995, pp. 991-1000
Citations number
47
Categorie Soggetti
Ecology
Journal title
ISSN journal
00220477
Volume
83
Issue
6
Year of publication
1995
Pages
991 - 1000
Database
ISI
SICI code
0022-0477(1995)83:6<991:AMPAAG>2.0.ZU;2-A
Abstract
1 Seedlings of the annual grass Vulpia ciliata ssp. ambigua were inocu lated in the laboratory with a factorial combination of the cosmopolit an root pathogen Fusarium oxysporum and an arbuscular mycorrhizal (AM) fungus (a Glomus sp.) before being planted out into a natural populat ion of V. ciliata at Mildenhall, UK, from which both fungi had been is olated. 2 At both 62 and 90 days after transplantation, inoculation wi th Glomus sp. had not increased plant P concentrations, but had protec ted the plants from the deleterious effects off. oxysporum infection o n shoot and root growth, apparently by suppressing pathogen developmen t in roots. The effects of Glomus sp. on plant performance were neglig ible in the absence of F. oxysporum. 3 After transplantation, comparis ons made of the root-infecting mycofloras of uninoculated plants and p lants inoculated only with Glomus sp. showed that the latter developed fewer naturally occurring infections of F. oxysporum and Embellisia c hlamydospora, two species of fungi which are correlated with reduction s in fecundity in natural populations of V. ciliata. 4 These results c onfirm conclusions from previous experiments that the main benefit sup plied by AM fungi to V. ciliata is in protection from pathogenic fungi , rather than improved P uptake, and indicate that AM colonization sig nificantly alters the root-infecting mycoflora of V. ciliata. We propo se that AM fungi may confer similar benefits in other plant species, w hich may account for the difficulty in demonstrating a benefit of AM f ungi to the P nutrition of host plant species under natural conditions .