Soil Tillage Affects the Community Structure of Mycorrhizal Fungi in Maize Roots

Abstract

In this study we tested whether communities of arbuscular mycorrhizal fungi (AMF) colonizing the roots of maize (Zea mays L.) were affected by soil tillage practices (plowing, chiseling, and no-till) in a long-term field experiment carried out in Tänikon (Switzerland). AMF were identified in the roots using specific polymerase chain reaction (PCR) markers that had been developed for the AMF previously isolated from the soils of the studied site. A nested PCR procedure with primers of increased specificity (eukaryotic, then fungal, then AMF species or species-group specific) was used. Sequencing of amplified DNA confirmed that the DNA obtained from the maize roots was of AMF origin. Presence of particular AMF species or species-group was scored as a presence of a DNA product after PCR with specific primers. We also used single-strand conformation polymorphism analysis (SSCP) of amplified DNA samples to check if the amplification of the DNA from maize roots matched the expected profile for a particular AMF isolate with a given specific primer pair.Presence of the genus Scutellospora in maize roots was strongly reduced in plowed and chiseled soils. Fungi from the suborder Glomineae were more prevalent colonizers of maize roots growing in plowed soils, but were also present in the roots from other tillage treatments. These changes in community of AMF colonizing maize roots might be due to (1) the differences in tolerance to the tillage-induced disruption of the hyphae among the different AMF species, (2) changes in nutrient content of the soil, (3) changes in microbial activity, or (4) changes in weed populations in response to soil tillage. This is the first report on community composition of AMF in the roots of a field-grown crop plant (maize) as affected by soil tillage.

Arbuscular mycorrhiza, rhizospheric microbe populations and soil enzyme activities in citrus orchards under two types of no-tillage soil management

“…The percentage of root length with arbuscules considered the major site of exchange between the fungus and host (Smith, 1995) was significantly higher in the soil layers above 40 cm in NN orchards compared to the NH orchards. This result shows that a natural grass cover is a better soil management system for improving citrus AM due to the changes in weeds populations in accordance with the earlier work by Jansa et al (2003). In our experiment, significantly higher spore numbers and hyphal length densities in the soil layers above 40 cm were observed in the NN orchards which might be due to the direct effects of increased numbers of plant species and a higher density of plant roots available for colonization.…”

Diversity of Arbuscular Mycorrhizal Fungi in Horticultural Production Systems of Southern Chile

“…represented each about 60 % of all AM fungal species found clearly the majority of the AMF community ( Figure 1). It is not surprising that most of AM fungi spores owned to the Glomus genus because this is the prevailing genus in agricultural soils among the AM species described so far (Jansa et al, 2003), and also in Chile, in a wheat-oat crop rotation with the application of different tillage systems in an Ultisol most species belonged to the genus Glomus (Castillo et al, 2006b). Similar results were obtained from European grasslands (Oehl et al, 2004).…”

Effects of different management practices on arbuscular mycorrhizal fungal diversity in maize fields by a molecular approach

“…In addition, OTU GIG_S26, grouping many sequences related to Gigasporales, was found in soil under all treatments. This finding was rather unexpected since members of this family are not usually detected (either as spores or sequences obtained from crop plants) in agricultural fields upon soil disturbance imposed either through agricultural use or by heavy landscaping machinery (Jansa et al 2003;Mathimaran et al 2007), but are in line with the results of Oehl et al (2005Oehl et al ( ,2010 based on spore identification tools from field samples. The results obtained with the GOCC56/GOCC427 primer pair highlights the difficulty of detecting Paraglomeraceae in root samples, as already reported by (Hijri et al 2006).…”