This research was performed in a semi-controlled greenhouse of the "Estación Experimental Canchones", in which the evolution of the effect of the mycorrhizal fungi over the growth parameters, differentiation, biomass, stress indicators and biochemical indicators for the production of the horticultural seedlings; and the percentage of mycorrhization obtained was evaluated. Inodorous type honeydew melon was used as the plant model. The mycorrhizal fungus Glomus intraradices Schenk and Smith, commercially known as MYCOSYM TRITON, was used for the inoculation at the moment of sowing with doses of 0; 20; 40 and 80 spores per plant. A completely randomized design was used; analysis used a factorial analysis variance (ANOVA) with the a posteriori LSD, using the statistical software INFOSTAT and an alpha value of 0.05. The results obtained in the destructive sample on the 50th day after sowing showed that the treatment with 40 spores per plant produced maximum root biomass, low etiolation index, a high value of the proportion of dry root weight to dry shoot weight. However, the activity of both endogenous and induced enzymes of nitrate reductase measured in the leaves was unaffected. We conclude that the symbiotic association between the roots of the melon plants and the mycorrhizal species Glomus intraradices produced a greater root biomass and very favorable conditions for transplanting.