THE DISTINCTNESS AND DIVERSITY OF ETHIOPIAN BARLEYS

The relative diversity and distinctness of Ethiopian barleys has been investigated using (1) morphology/isozyme/hordein polymorphisms and (2 ) RFLP markers. In the former a set of 51 landraces from over the whol e of Ethiopia was compared with Iranian landraces based on data from p revious studies and new hordein data. The two sets of landraces were f ound to have a comparable diversity. The Ethiopian ones are more diver se morphologically (5 traits), are similar in numbers of alleles per p rotein locus (17 loci) and in genetic differentiation, but are less di verse in average heterozygosity per locus and degree of polymorphism. However, on the basis of the hordein data the two sources of germplasm are very distinct. The correlation between morphological and protein diversity is very low. In the RFLP study 28 probes evenly distributed across the genome were used to analyse 43 Ethiopian landraces (represe nted by one single genotype) and to compare them with modern cultivars from North America, Europe and Japan, as well as 3 landraces from Ira n, 1 from Nepal, and 1 accession of H. spontaneum from Afghanistan. Th e major finding was that the Ethiopian germplasm appears to be signifi cantly less diverse than the modern germplasm but that it is genotypic ally very distinct. The apparent contradiction between a high diversit y of useful genes coming from Ethiopia and an apparently low diversity at the DNA level is discussed.