Schriften zu Genetischen Ressourcen - Genres

Results and discussion
M. SCHOLZ, B. RUGE and B. HACKAUF
Interspecific hybridisation between H. vulgare and H. bulbosum was used to extend
genetic variability in barley. Eleven offspring plants were analysed with respect to their
hybrid character. Nine out of eleven plants examined displayed 21 chromosomes (Fig.
1).
Fig. 1: 21 chromosomes of a F1 hybrid from a cross between H. vulgare and H.
bulbosum
The occurrence of four plants with 19 and 20 chromosomes, respectively, indicates the
elimination of chromosomes. Chromosomal instability is well known in triploid hybrids
(PICKERING 1992). Initially, the isozyme markers Lap2, Lap3 and Got1 were used to
identify H. bulbosum chromosomes 7H b , 4H b and 6H b , respectively (Fig. 2). Using these
markers, between one and three H. bulbosum chromosomes could be identified in
different F1 hybrids (Tab.1).
For the majority of analysed SSRs a more efficient amplification could be observed in H.
vulgare as compared to H. bulbosum, possibly due to primer mismatches in the latter
species. However, first results for HvALAAT and HvU56406 encoding an alanine
aminotransferase and a methyljasmonate-inducible lipoxygenase 2, respectively,
demonstrate the potential of SSR markers to identify H. vulgare × H. bulbosum hybrids
(Fig. 3). While HvALAAT has previously been mapped on chromosome 1H in barley, the
chromosomal localisation of HvU56406 is still unknown (RAMSAY et al. 2000). Additional
mapped SSR should enable to identify each of the seven chromosomes from H.
bulbosum.
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