Comparative Yield Analysis of Stem Rust Resistant Wheat Mutant Lines and Their Parent Varieties

Abstract

Wheat (Trticum aestivum L.) farmers in Kenya are faced with a major threat on their wheat farming from stem rust (Puccinia graminis f. sp tritici). Smallholder’s farmers are earning low income from their wheat farming but there’s high demand for wheat products. The interaction between wheat and stem rust in a favourable environment causes complete crop failure. This study aimed to assess yield potential of stem rust resistant mutant’s in comparison with their parent varieties. The objective was to select sample of high yielding stem rust resistant mutant lines to be introgressed into adaptable Kenyan wheat background. Seventeen wheat genotypes comprising eight mutant lines, two parents and seven commercial checks were evaluated. The experiments were conducted in the years 2012 and 2013 at University of Eldoret, KALRO Njoro and Kitale.  Randomized Complete Block Design with three replications was used to conduct the experiement. Yield data and stem rust response were collected and analysed. Response to stem rust was recorded based on modified Cobb’s scale while a severity was recorded on a scale of 0-100%. Grain yield ranged from 0.69-4.35 t ha-1 and disease response range from moderately resistant to susceptible. Genotype, location and genotype x location interaction for yield and disease response were significant at P < 0.05. Results showed two mutant lines SP-21 and SP-26 were high yielding and moderately resistant to stem rust. Considering high yields and stem rust resistance they were superior to their parents and can undergo further tests for future release.