%0 Artículo (Article) %A Cuadros G., Guillermo Andrés %I Corporación Colombiana de Investigación Agropecuaria (Agrosavia) %D 2019 %G Español (Spanish) %T Symbiotic asociation of arbuscular mycorrhizal fungi and the root system of cocoa (Theobroma cacao L.) seedlings: effect of formononetin and phosphorus availability at soil level %U http://hdl.handle.net/20.500.12324/35105 %X The symbiosis established between cacao plants and arbuscular mycorrhizal fungi (AMF) adds nutritional and competitive benefits for the plant, especially in conditions with a low availability of nutrients. We evaluated three levels of phosphorus (5, 20 and 40 ppm) and the presence or absence of isoflavone formononetin. A Phosphorus level of 14 ppm, without isoflavone or inoculation was the control. All treatments were inoculated with HFMA with the exception of the control. A completely randomized design was used. The morphological characters of the plant at 70, 110 and 150 days after inoculation were determined. The results showed no difference in the response to the morphological characters of the plant with the varied availability of isoflavone during the three sampling. The root length showed significant differences in the different sampling times (70, 110 and 150 days of inoculation), this response being dependent on the availability of P and plant-mycorrhizal interactions. The number of spores demonstrated differences between the samples of 110 and 150 days of inoculation in the presence and absence of isoflavone, suggesting an early stimulation in the establishment of the symbiotic relationship of formononetin in the process of germination and formation of fungal structures.