A novel multiscale Monte-Carlo Ray Tracing (MCRT) model in the large eddy simulation-one-dimensional turbulence (LES-ODT) framework for participating gray media is developed. LES-ODT is based on a hybrid simulation of the large scales within LES and 1D ODT fine-resolution solutions embedded in the LES. Radiation is solved within the ODT domain at the subgrid scale where a combination of stochastic and deterministic solutions allows the treatment of different processes governing the transport and chemistry for scalars and momentum. The MCRT model is implemented in a non-homogeneous auto-ignition isotropic turbulence simulation and compared to direct numerical simulations (DNS) of the same configuration. This configuration exhibits complex coupling between turbulent transport and molecular processes, diffusion, reaction and radiation, under highly transient conditions. Implementation in the LES-ODT framework is performed for different cases of optical thicknesses. Results of the simulations are compared to DNS statistics. The comparison of the different statistics shows a satisfactory agreement. (C) 2016 Elsevier Ltd. All rights reserved.