The role of arbuscular mycorrhizal fungi in grain production and nutrition of sorghum genotypes: Enhancing sustainability through plant-microbial partnership

The responsiveness of 3 landrace (open-pollinated) sorghum cultivars and 3 modern (commercial) hybrids to arbuscular mycorrhizal (AM) fungi and commercial fertilizers were assessed. Sorghum genotypes were selected to represent a range of sorghum breeding development. This comparison was conducted to link grain production and quality with crop nutrition strategies (AM symbiosis versus fertility amendments). The open-pollinated cultivars produced an average of 206% more vegetative biomass and 285% more grain per plant, compared to commercial hybrids when grown with AM fungi and no fertilization. Furthermore, the average protein production of open-pollinated cultivars was 320% greater, compared to hybrids grown under the same low-fertility conditions. Percent AM root colonization was 149% greater in open-pollinated cultivars compared to hybrids, and across all genotypes, AM colonization was significantly correlated with total grain mineral content. Sorghum cultivars were significantly more responsive to mycorrhizal symbiosis than commercial hybrids for nutrient uptake and subsequent grain production and quality, while hybrids were significantly more responsive to fertilization.