Prediction of a possible co-evolutionary process is critical in a plant-pathogen interaction basing on a host plant’s origin, its molecular characteristics and involved pathogen’s history. Therefore, two successive screening experiments in completely randomized design were set up at Muguga-south glasshouses in Kenya. The study objective was to determine whether the resistant napier grass accessions exhibited any indications of selection preference to origin as may have been influenced by the African pathogen. Smutted tiller numbers and subsequently proportions of smutting among the accessions were determined to enable the within and across evaluation of the accessions’ neighbour joining groups. The accessions exhibited observable differences with 67.9% and 32.1% smutting and not smutting respectively. Further, on across evaluation of the respective groups; the Southern Africa neighbour joining group had the most asymptomatic accessions at 35.29% whereas the USA 1 and 2 had the least at 5.88%. On within the groups’ evaluation, the Southern Africa and USA 2 had the highest and least relative resistance indices of 0.2900 and -1.2606 respectively. Whereas, for the relative susceptibility indices the USA 2 had the highest and Southern Africa group the least at 0.2940 and -0.1732 respectively. The results suggest that resistance trait selection preference seems to be skewed towards accessions whose origin is from Africa especially south of Africa where the grass traces its origin at the Zambezi valley.
