Arbuscular mycorrhizal species vary in their impact on nutrient uptake in sweet corn (Zea mays) and butternut squash (Cucurbita moschata)

Abstract

An increasing demand for organic produce, coupled with the need to reduce reliance on the diminishing resource of rock phosphate, has bolstered interest in the use of arbuscular mycorrhizae (AMF) as a biofertilizer. AMF are symbiotic fungi that colonize the roots of most crops and transfer nutrients from the soil to their hosts in exchange for carbon. While past studies have shown that mixed AMF communities grown from field soil can increase the yield of many crops, the targeted use of individual AMF species on host plants is a promising avenue to enhance nutrient uptake. We inoculated sweet corn (Zea mays) and butternut squash (Cucurbita moschata) seedlings with nine individual species of AMF and one mixed indigenous population to determine the most beneficial symbionts for enhancing mineral nutrient concentration and yield. Overall, level of root colonization was correlated with phosphorus (P) concentration of aboveground biomass. Corn and squash grown in association with AMF species in the Rhizophagus genus had the highest level of root colonization and tissue P concentration. Claroideoglumus etunicatum and Gigaspora margarita increased calcium (Ca) and magnesium (Mg) concentration in corn and Gigaspora rosea increased calcium in squash. S. constrictum and G. rosea positively impacted sweet corn seedling biomass. Based on this evidence, AMF species vary in their benefit to plant nutrient uptake and the most beneficial species depend on host. Further research on the effectiveness of inoculating individual AMF species across a range of hosts and ecosystems will prove useful in the development of host-targeted AMF biofertilizers.

Linking soil health to human health: Arbuscular mycorrhizae play a key role in plant uptake of the antioxidant ergothioneine from soils

“…Differences in the impact of AMF species on nutrient uptake and growth of plant hosts have been documented, and species with a greater ability to access and transfer nutrients to host plants at lower C costs better benefit plant health. (Carrara & Heller, 2022; Cavagnaro et al, 2005; Feddermann et al, 2008; Hart & Reader, 2002; Lanfranco et al, 2018; Munkvold et al, 2004). Past work on mycorrhizal nitrogen (N) uptake and transfer to host plants has shown that direct mycorrhizal uptake of amino acids from soil is an important component of the plant‐mycorrhizal N economy (Talbot & Treseder, 2010; Whiteside et al, 2012).…”

“…For this reason, the black bean trial included three additional AMF inoculations compared with the asparagus trial. We chose to use all available species based on our previous work that found a range of colonization efficiencies across AMF and host species in corn ( Z. mays ) and butternut squash ( Cucurbita moschata ) (Carrara & Heller, 2022). Wheat and oat were inoculated with only Scutellospora calospora and Claroideoglomus etunicatum based on previous trials completed in our lab that showed that inoculation with these species had the highest colonization efficiency of these hosts (data not shown).…”

Divergent colonization traits, convergent benefits: different species of arbuscular mycorrhizal fungi alleviate Meloidogyne incognita damage in tomato

“…It has been observed that either Rhizophagus spp. or F. mosseae have an advantage over other AMF species in root colonization on different plant hosts (e.g., Blažková et al 2021 ; Carrara and Heller 2022 ; Jansa et al 2008 ; Säle et al 2021 ; Voříšková et al 2019 ). A rapid colonization rate could provide them with greater ability to compete with PPN for space in the rhizosphere and/or the roots.…”

“…and Gigaspora spp. show increased magnesium and calcium uptake (Carrara and Heller 2022 ). Also, a recent study found that different genetic organization (dikaryotic versus homokaryotic) of strains within the same species ( Rhizophagus irregularis ) can differentially affect the response of plants to mycorrhizas (Terry et al 2023 ).…”

Inoculation of black turtle beans (Phaseolus vulgaris) with mycorrhizal fungi increases the nutritional quality of seeds

“…This observed variability in the benefits of mycorrhizal inoculation on host plants is likely due to a range in the plant C costs of nutrient return across AMF species. The most cost‐effective AMF species, or the AMF species with the highest nutrient acquisition efficiency, provides the greatest benefit to plant fitness (Carrara & Heller, 2022; Carrara et al., 2023; Carrara et al., 2023; Kiers et al., 2011; Van't Padje et al., 2021; Werner & Kiers, 2015). As such, trials that assess plant responses to inoculation with a variety of individual AMF species are a promising avenue toward developing host‐targeted inocula that can enhance nutrient uptake and crop yield to the greatest extent.…”