Biochemical and morphological variation among barley landraces
Sixty two barley (Hordeum vulgare L.) pure lines derived from landraces, mainly farmers' cultivars, were evaluated at two locations in north Shewa, Ethiopia with the aims (i) to know the extent of variability for quantitative characters and seed storage proteins profile, (ii) to determine their genetic relationships, and (iii) to evaluate their potential for improvement through selection. The genetic relationship as revealed by the hierarchical cluster analysis based on data from SDS-PAGE and quantitative characters explicitly showed tightly grouping of lines derived from landraces bearing the same name indicating the predominance of variation among the cultivars rather than within cultivars. Mean genetic distance between lines within cultivars was very low (0.094 in Mage to 0.567 in Kessele). Accordingly, genetic advance through selection for the different agronomic characters within cultivars was lower than the corresponding values observed for all landraces. Hence, progress through pure line selection cannot be warranted. Instead, rouging carefully the inferior biotypes or off types from farmers' cultivars may help exploit their maximum genetic potential than attempting to improve their productivity through pure line selection and evaluation method. Evaluation of landraces from other sources, from within or outside the environment, could be explored to get better yielding land races than the existing ones. In the long term, crossing may be scheduled between cultivars which appear to be diverse in order to maximise the potential gain from selection in the progeny.
Key Words: Cluster analysis, Ethiopia, genetic distance, Hordetun vulgare, pure line selection