A “paper bridge” system to improve in-vitro propagation of arbuscular mycorrhizal fungi

Botany ◽  
2010 ◽  
Vol 88 (6) ◽  
pp. 617-620 ◽  
Author(s):  
Yolande Dalpé ◽  
Sylvie Seguin

The in-vitro culture of arbuscular mycorrhizal fungi on excised roots, especially when performed on bi-compartmented Petri dishes, has proven to be an efficient system for the production of root-free fungal material. However, even after the contact between fungal hyphae and the excised roots in the proximal root compartment has occurred, up to several weeks may be required for the fungal runner hyphae to cross the median Petri dish wall and reach the distal fungal compartment. This delay is particularly long for the cultivation of slow-growing strains that usually colonize the substrate less aggressively. The delay is due to the difficulty the runner hyphae have in crossing the median Petri dish wall that separates compartments. To facilitate the passage of the fungus across the median wall, a “paper bridge” system has been devised and tested with a number of arbuscular mycorrhizal fungal strains. This method substantially accelerated fungal propagation and simplified the manipulations necessary. The proposed paper-bridge system is described and its advantages discussed.

2001 ◽  
Vol 79 (10) ◽  
pp. 1161-1166 ◽  
Author(s):  
John N Klironomos ◽  
Miranda M Hart ◽  
Jane E Gurney ◽  
Peter Moutoglis

Arbuscular mycorrhizal fungal communities in northern temperate ecosystems must function during extremes in environmental conditions. However, it is not known if arbuscular mycorrhizal fungi that co-exist in soil communities have similar tolerances to stresses such as drought and freezing. The phenology of arbuscular mycorrhizal fungi was determined over one year in a community in southern Ontario, Canada. Five fungal species from the same community were then used to inoculate five plant species, in all possible combinations, and were subjected to either a freezing treatment or a drought treatment after which new seedlings were transplanted into the treated pots. The percent colonization of roots of each plant species was measured as the difference in mean colonization from the control. Freezing reduced percent colonization in almost every case, whereas drought resulted in both increased and decreased percent colonization. Fungal species responded differently to the treatments, and there was a pronounced plant × fungus effect. These results support the hypothesis that distinct functional groups of arbuscular mycorrhizal fungi exist, and these may determine plant community structure.Key words: arbuscular mycorrhizal fungi, freezing, drying, functional diversity.


HortScience ◽  
2013 ◽  
Vol 48 (7) ◽  
pp. 897-901 ◽  
Author(s):  
Cinta Calvet ◽  
Amelia Camprubi ◽  
Ana Pérez-Hernández ◽  
Paulo Emilio Lovato

Inoculum of arbuscular mycorrhizal fungi, with growing use in horticulture, is produced mainly in two technically different cultivation systems: in vivo culture in symbiosis with living host plants or in vitro culture in which the fungus life cycle develops in association with transformed roots. To evaluate the effectiveness and the infectivity of a defined isolate obtained by both production methods, a replicated comparative evaluation experiment was designed using different propagules of Rhizophagus irregularis produced in vivo on leek plants or in vitro in monoxenic culture on transformed carrot roots. The size of the spores obtained under both cultivation methods was first assessed and bulk inoculum, spores, sievings, and mycorrhizal root fragments were used to inoculate leek plantlets. Spores produced in vitro were significantly smaller than those produced in vivo. Although all mycorrhizal propagules used as a source of inoculum were able to colonize plants, in all cases, leek plants inoculated with propagules obtained in vivo achieved significantly higher mycorrhizal colonization rates than plants inoculated with in vitro inocula. Inoculation with in vivo bulk inoculum and in vivo mycorrhizal root fragments were the only treatments increasing plant growth. These results indicate that the production system of arbuscular mycorrhizal fungi itself can have implications in the stimulation of plant growth and in experimental results.


Author(s):  
Yuying Ma ◽  
Huanchao Zhang ◽  
Daozhong Wang ◽  
Xisheng Guo ◽  
Teng Yang ◽  
...  

Arbuscular mycorrhizal fungi (AMF) provide essential nutrients to crops and are critically impacted by fertilization in agricultural ecosystems. Understanding shifts in AMF communities in and around crop roots under different fertilization regimes can provide important lessons for improving agricultural production and sustainability. Here, we compared the responses of AMF communities in the rhizosphere (RS) and root endosphere (ES) of wheat ( Triticum aestivum ) to different fertilization treatments: Non-fertilization (Control), mineral fertilization only (NPK), mineral fertilization plus wheat straw (NPKS), and mineral fertilization plus cow manure (NPKM). We employed high-throughput amplicon sequencing and investigated the diversity, community composition, and network structure of AMF communities to assess their responses to fertilization. Our results elucidated that AMF communities in the RS and ES respond differently to fertilization schemes. Long-term NPK application decreased the RS AMF alpha diversity significantly, whereas additional organic amendments (straw or manure) had no effect. Contrastingly, NPK fertilization increased the ES AMF alpha diversity significantly, while additional organic amendments decreased it significantly. The effect of different fertilization schemes on AMF network complexity in the RS and ES were similar to their effects on alpha diversity. Changes to AMF communities in the RS and ES correlated mainly with the pH and phosphorus level of the rhizosphere soil under long-term inorganic and organic fertilization regimes. We suggest that the AMF community in the roots should be given more consideration when studying the effects of fertilization regimes on AMF in agroecosystems. Importance Arbuscular mycorrhizal fungi are an integral component of rhizospheres, bridging the soil and plant systems and are highly sensitive to fertilization. However, surprisingly little is known about how the response differs between the roots and the surrounding soil. Decreasing arbuscular mycorrhizal fungal diversity under fertilization has been reported, implying a potential reduction in the mutualism between plants and arbuscular mycorrhizal fungi. However, we found opposing responses to long-term fertilization managements of arbuscular mycorrhizal fungi in the wheat roots and rhizosphere soil. These results suggested that changes in the arbuscular mycorrhizal fungal community in soils do not reflect those in the roots, highlighting that the root arbuscular mycorrhizal fungal community is pertinent to understand arbuscular mycorrhizal fungi and their crop hosts’ responses to anthropogenic influences.


2017 ◽  
Vol 31 (1-2) ◽  
pp. 17-24
Author(s):  
Hari Prasad Aryal

 The technique of in vitro propagation of Arbuscular mycorrhizal fungi has been developed over the past few decades and opens up areas of studying plant-fungi interactions. It is a scientific break through, especially for the study of the Arbuscular mycorrhizal fungi, since these obligate symbionts depend on host plant. The objective of this paper is to find out the in vitro culture of Arbuscular Mycorrhizal Fungi using Root Organ Culture technique. Ascertain of root colonization of these fungi could be affected in vitro without undertaking complex and complicated culture conditions. This could form an economically viable technique for root organ culture of Arbuscular mycorrhizal fungi.


Mycorrhiza ◽  
2009 ◽  
Vol 19 (5) ◽  
pp. 347-356 ◽  
Author(s):  
Liesbeth Voets ◽  
Ivan Enrique de la Providencia ◽  
Kalyanne Fernandez ◽  
Marleen IJdo ◽  
Sylvie Cranenbrouck ◽  
...  

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