Genetic variability in barley (Hordeum vulgare L.) landraces from Ethiopia as measured by morphological characters and SDS-page of seed storage proteins

Abstract

Data on 44 barley landraces comprising collections and farmers’ cultivars from north Shewa, Ethiopia were studied for variability in morphological characters and Sodium Dodecyl Sulphate Polyacrylamide Gel Electophoresis (SDS-PAGE) of seed storage proteins. The phenotypic frequencies of morphological characters (qualitative and quantitative) were analysed by the Shanon Weaver diversity index (H’) to estimate within landrace genetic variability for individual characters. Variability for seed protein banding patterns was assessed by SDS-PAGE. Both morphological and SDS-PAGE data demonstrated the variability existing in the landraces. H’ values pooled over morphological characters ranged from 0.12 to 0.58. Among the qualitative characters, landraces showed higher levels of polymorphism for spike type than for kernel color, spike density and caryopsis type (covered or naked). Caryopsis type was the least diverse character observed. Diversity for quantitative characters pooled over landraces was generally very high especially for number of seeds spike-1 and days to maturity with respective H’ values of 0.90 and 0.98. DS-PAGE data based on representative lines from each landrace showed very low to high within landrace variability for banding patterns. Lines from landraces differed from each other in number and migration distances of bands. Some landraces that looked uniform for spike morphology also showed differences in banding patterns. It was also observed, on the other hand, that some landraces displaying different spike characters and hence assumed to exhibit differences of comparable magnitude in storage protein variability did not reveal much differences. Variability between landraces was higher than within landraces and variability within farmers’ cultivars was lower than within accessions. Clustering results of landraces from SDS-PAGE data were different in composition from those formed by morphological characters. Clustering from morphological data highlighted distinct grouping of landraces based on similarities in morphological characters whereas SDS-PAGE data did not depict such distinctness.