Breeding Potential of Exotic Barley Germplasm

Utilization of exotic germplasm offers an approach to broaden genetic variability in breeding populations. This study was conducted in order to 1) compare germplasm of exotic origin with adapted Swedish barleys with respect to genetic differences and 2) to evaluate first cycles of pre-breeding i.e. agronomic traits in complex exotic x adapted crosses. Allozyme studies showed the following Nei\u27s gene diversities among parents: 0.13 (adapted parents), 0.16 (landraces) and 0.25 (H. spontaneum). Cluster analysis based both on allozyme and agronomic data indicated that parental groups were genetically divergent. Earliness, straw length, number of ears per plant and thousand kernel weight (TKW) were studied. The best sources for earliness were adapted parents and landraces. Mean straw length was greatest in H. spontaneum lines. Number of ears per plant was quite similar in all groups. The highest TKW was among landraces and adapted parents. Hybrids from the complex crossing programme exceeded parents in earliness and TKW. An index composed from the four traits showed the most favorable frequency distributions for adapted parents and hybrids. Both genetic and agronomic studies indicate that new variation from exotic germ plasm may be introduced into barley breeding material. In addition, through recombination, agronomically valuable genotypes can be obtained and they can be utilized in long-term breeding programes