Evaluation of Inoculation Methods and Resistance of some Sorghum Genotypes to Bacterial Leaf Streak (Xanthomonas campestris pv. holcicola)

Abstract

Six methodologies of inoculation were compared under field condition. Application of finely ground-infected leaves in leaf whorls and spraying with bacterial suspension after wounding leaves with sterile fine sand gave the most uniform and consistent results. Using
these methods of inoculation, 121 sorghum genotypes were screened for resistance to Xanthomonas campestris pv. holcicola (Xch) under field and greenhouse conditions at the Alemaya University Research Center (eastern Ethiopia) after insuring effective inoculation method. Out of the 121 sorghum genotypes examined in the greenhouse, 31, 35 and 54 lines were resistant, moderately resistant and susceptible, respectively. In the field study, 87.5%, 5% and 7.5% of the genotypes were resistant, moderately resistant and susceptible, respectively. In this study it was possible to identify that 25 sorghum genotypes were found to be resistant to sorghum bacterial leaf streak both at the seedling and adult stages of growth with the desirable agronomic characteristics. These genotypes could form the basis for a breeding program to develop sorghum cultivars more resistant to this disease under cool growing conditions of Hararghe Highlands.