Comparative assessment of isozyme diversity in barley from Ethiopia and Tibet
Zhang, Q., X. Dai and M. A. Saghai Maroof. 1992. Chinese Journal of Genetics 19:119-126, Allerton Press,Inc.,New York.
ABSTRACT It was proposed over half a century ago that there were two major gene centers of cultivated barley (Hordeum vulgare L.): Ethiopia and Tibet. However, the relative amounts of genetic diversity in these two regions have never been critically assessed. In this paper, we analyzed genetic variation at six isozyme loci (Est1, Est2, Est3, Est4, Acp1 and Got1) for a total of 777 barley accessions from Ethiopia and Tibet. Very striking differences were observed between barleys from these two regions both in single locus allelic frequency and in multilocus genotype combination. The results also showed that about equal amounts of genetic variation were present in these two regions when genetic diversity was evaluated at single locus level, while the degree of genetic diversity was significantly higher in Tibetan barley than that of Ethiopian barley when multilocus genotype combinations were assessed. Comparison of allelic composition between this analysis and previously reported studies showed that there were alleles at almost every locus that were observed in other parts of the world but not found in these two regions. The implication of these results in germplasm conservation was discussed.
Key words Hordeum vulgare L., isozyme, genetic diversity, gene centers, population genetics