Progeny analysis by isozyme markers in the polyploid liverwort Plagiochasma rupestre

Crossing experiments showed that the polyploid (n = 18) bisexual liverwort Plagiochasma rupestre is capable of self-fertilization, as well as cross-fertilization. Progeny of natural and controlled fertilizations were analysed with respect to segregation of two isozyme markers. No segregation was observed in offspring from field-fertilized sporophytes. Induced fertilizations showed that esterase activity is controlled by one locus. The activity of glutamate-oxaloacetate transaminase is controlled by two genes. Isozyme patterns are explained by genome duplication (n = 18), but the two chromosome sets behave independently. Allopolyploidy seems therefore to be the most likely origin of the duplication. Keywords: bryophytes, progeny analysis, isozymes, polyploidy.