Arbuscular mycorrhizal fungal diversity in wheat agro-ecosystems in Southern Chile and effects of seed treatment with natural products

Abstract

Arbuscular mycorrhizal (AM) fungi are important for P uptake in Andisols cultivated with wheat. We assessed AM fungal diversity in field experiments established with wheat cultivated after AM host plants and non-host plants at three locations of the Araucanía Region. Wheat seed was treated with two natural products: Fosfobio (FOS), mixture of P-solubilizing bacteria and N 2 -fixing bacteria; and Myconate (MYC), product containing formononetin. For investigations of AM fungal diversity, soil samples were taken before planting and after harvest of wheat. The morphological spore analyses resulted in 26 species, belonging to 10 families and 16 genera; 5 species belonged to Acaulospora (31.2% of total), and 3 to Claroideoglomus (18.8%). Claroideoglomus claroideum was the prevalent while Ambispora leptoticha, Dominikia aurea, and Glomus badium presented the lowest frequency. The AM fungal species distribution was strongly dependent on the location, and richness at planting of wheat was higher when a non-host for AM fungi had been grown before. There appeared to be a tendency that through wheat cultivation, the richness of AM fungal species decreased from time of planting to harvest when the pre-crop was a non-host; when the pre-crop was AM host there was no apparent decrease in AM species richness through wheat cultivation. Natural products did not significantly influence grain yields. However, there was a tendency that MYC increased average grain yields by 7%. It is discussed that increased AM root colonization, as by MYC and improved P-uptake by AM fungi is more important than inoculation of seed with P-solubilizing microbes.

Analysis of Arbuscular Mycorrhizal Fungal Inoculant Benchmarks

“…This is not surprising as many results from greenhouse and field trials have also proven the positive effects of AMF inoculation. AMF inoculation primarily boost nutrient mobilization and uptake [ 26 , 53 , 54 , 55 , 56 , 57 ]. AMF inoculation enhances uptake and transportation of nutrients such as P, N, Mg, K, Fe, Cu, Zn and Mo.…”

“…Cereal production clearly dominated the inoculation market space due to relatively greater quantities of cereal crops cultivated on large arable lands globally. Furthermore, during the early growth stages of production, P becomes a limiting nutrient for cereals, especially for root development, therefore, mycorrhizal-based inoculants would be vital in P acquisition [ 55 ]. Horticulture is the other major target market for several inoculant products.…”

Functional land-use change effects on soil fungal communities in Chilean temperate rainforests

“…The opposite pattern was found in the plot representing an initial successional state (clear-cut forest), were richness and relative abundance of saprotrophic and EM fungi were lowest. While animal and plant communities have been shown to have a high degree of nestedness (James et al, 2012), this concept has rarely been applied to soil microbial communities (Castillo et al, 2016). Nestedness, however, should not be mistaken for community composition or structure; the latter refers to the abundance and type of species present in a community.…”

Phosphorus Acquisition Efficiency Related to Root Traits: Is Mycorrhizal Symbiosis a Key Factor to Wheat and Barley Cropping?

“…Aguilera et al ( 2014 , 2017 ) analyzing spore morphology on acidic soils under continuous wheat cropping, found 24 AM fungal species, being Acaulospora and Scutellospora the dominant genera. In another study under similar conditions in acidic soils, Castillo et al ( 2016b ) described 26 fungal species with a prevalence of Acaulospora and Claroideoglomus . This dominance of Acaulospora spores in soils cropped with wheat was also observed by Hu et al ( 2015 ) in North China and by Nadji et al ( 2017 ) in Algeria, however in the last study Glomeraceae species was also detected as highly abundant.…”