Optimization of the production of mycorrhizal inoculum on substrate with organic fertilizer

Abstract

The system for production of inoculum of arbuscular mycorrhizal fungi (AMF) using sand and vermiculite irrigated with nutrient solution is promising. However, organic amendments added to the substrate can stimulate sporulation of AMF and replace the nutrient solution. The aim of this study was to maximize the production of AMF (Acaulospora longula, Claroideoglomus etunicatum, Dentiscutata heterogama and Gigaspora albida) using selected organic substrates (vermicompost, coir dust and Tropstrato) together with sand and vermiculite. The production of spores varied among the tested AMF and according to the organic source added to the substrate. The vermicompost promoted higher sporulation of A. longula in relation to the other AMF and substrates. The Tropstrato® inhibited the sporulation of D. heterogama while the reproduction of C. etunicatum was not affected by the organic compounds. The inoculum of A. longula also showed a high number of infective propagules and promoted biomass accumulation in maize plants. The system of inoculum production using sand and vermiculite + 10% vermicompost favors the production of infective inoculum of A. longula with the fungus benefiting growth of corn plants.

Enhancement of Colonisation of Soybean Roots by Arbuscular Mycorrhizal Fungi Using Vermicompost and Biochar

“…These results agree with [16] who found that a block treated with biochar alone recorded the highest abundance of spores, compared to blocks treated with a combination of biochar and mycorrhiza, and attributed this to the slow adjustment of the introduced mycorrhizal species to the environment. The results of this study also agree with [21], who found that substrates treated with vermicompost produced the highest number of mycorrhizal spoeres compared with substrates treated with coir dust and Topstrato TM . They attributed this to the high levels of phosphorous in the substrate provided by vermicompost, which played an improtant role in production of AM fungi propagules.…”

“…Furthermore, genera such as Glomus and Acaulospora produce small spores and are able to survive by adapting their sporulation patterns under unfavourable conditions like aridity [22]. The results of this study also agree with [21], who found that members of the Gigasporaceae family generally produce few spores and are incapable of colonising from hyphal fragments.…”

“…The results of this study differ with [25] who found that mycorrhizal colonisation and arbuscule formation significantly decreased with the increase of green compost in soil. [21] Suggested that some substances present in organic composts could have a phytotoxic effect and/ or inhibit the development of AM fungi.…”

Development of Carrier Based in Vitro Produced Arbuscular Mycorrhizal (AM) Fungal Inocula for Organic Agriculture

“…[41-43, 8, 44, 45]. Addition of organic residues to the substrate is known to increase AM fungal sporulation hence leading to increased inoculum production [46][47][48][49]. Douds et al [8] successfully produced AM fungal inoculum in compost mixed with vermiculite, perlite, or horticultural potting media and observed that the propagule numbers were maximum in vermiculite based media.…”

“…Addition of P increased both root growth and the percentage of root length colonized by AM fungi. If AM fungal isolates are produced in organic substrate with high P levels it is likely that the isolates will be more adapted to conditions of high P [51,49]. However, the overall least AM fungal interaction was observed in treatments 14 and 15.…”