| genetic diversity and adaptedness in tetraploid avena barbata and its diploid ancestors avena hirtula and avena wiestii. | avena barbata, a tetraploid grass, is much more widely adapted and successful in forming dense stands than its diploid ancestors. the success of such polyploids has often been attributed to heterosis associated with ability to breed true for a highly heterozygous state in which allelic differences between the parents are fixed in the polyploid by chromosome doubling. we have examined the relationship between genetic diversity and adaptedness for 14 allozyme loci in a. barbata and its diploid anc ... | 1991 | 1996323 |