Evaluation of advanced wheat (Triticum aestivum L.) lines for stem rust (Puccinia graminis f. sp. tritici) resistance and yield

Stem rust disease caused by Puccinia graminis f. sp tritici is a major challenge to wheat (Triticum aestivum) production in Kenya and other wheat growing countries of Africa and Asia. The current study aimed at evaluating sixty four wheat genotypes for stem rust resistance at seedling stage in a greenhouse; as well assessing the genotypes for stability in adult plant resistance to stem rust and yield across three sites in Kenya in an alpha lattice design with three replications. Seedling disease Infection Type (IT) ranged from “0” (immune) to “4” (susceptible), while adult plant infection assessed by disease Coefficient of Infection (CI) and Area Under Disease Progress Stairs (AUDPS) ranged from means of 0.2 to 1.7 and 30.2 to 1174.2, respectively. Mean grain yield ranged from 2.0 to 7.8 t ha-1. Genotype, location and genotype × location interaction for the AUDPS, CI, and yield were significant (P  0.01). There was a significant (P  0.01) linear and inverse relation of grain yield to AUDPS and CI. Considering the disease response, yield potential, and yield stability, genotypes KSL 42 and KSL 3 were consistently well ranked. These genotypes are suitable candidates for utilization in yield and stem rust resistance improvement programs in Kenya and potentially in other major wheat growing areas in Kenya and potentially in other major wheat growing areas globally, where stem rust is significant.