DEVELOPMENT OF LODGING RESISTANT BARLEY (Hordeum vulgare L.) LINES USING MUTATION BREEDING

Abstract

Barley (Hordeum vulgare L.) is one of the most important cereal crops in Kenya and the world’s fourth most important cereal grown mainly for fodder and beer production. Major constraints to high yield in barley include pests, diseases, changing climatic conditions, land fragmentation and most importantly lodging which causes yield losses of up to 60% and hence reduced grain yield per unit area due to shading of crop which results in reduced grain size. Kenyan varieties are prone to lodging which inevitably translates into severe yield losses that constrain farmers’ earnings hence the need to use mutation breeding to create genetic variability and develop lodging resistant lines. Barley seeds were irradiated at 300GY. A mutant (M1) population was established and two sets of 1000 heads selected. The resultant M2 seeds were planted in Njoro and Mau-Narok where selection was done using lodging scale (1-9), height of the plant, number of seeds per head, stem diameter and head size. Genetic diversity was tested at M2 using SSR markers to determine the presence of SSR marker for Btwd1 gene associated with lodging resistance. Of the 102 selected mutant lines, 61 lines had the band and 41 did not amplify. Data for various traits found significant differences among them. Correlation studies at M3, showed that head size, small stem diameter and height increase the chances of lodging. The results obtained from this study are of great help in future barley research where five resistant lines confirmed to have the presence of SSR markers to Btwd1 identified will be used in breeding.