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 how exotic mat
erial affected agronomic performance in complex crosses. Allozyme stud
ies showed the following Nei's gene diversities among parents: 0.13 (a
dapted parents), 0.16 (landraces) and 0.25 (H. spontaneum). Cluster an
alysis indicated that parental groups were genetically divergent. Earl
iness, straw length, number of ears per plant and thousand kernel weig
ht (TKW) were studied. Variation in agronomic traits showed the follow
ing pattern: landraces > H. spontaneum > adapted lines. The best sourc
es for earliness were adapted parents and landraces. Mean straw length
was greatest in H. spontaneum lines. Number of ears per plant was qui
te similar in all groups. The highest TKW was among landraces and adap
ted parents. Hybrids from the complex crossing programme exceeded pare
nts in earliness and TKW. An index composed from the four traits showe
d the most favorable frequency distributions for adapted parents and h
ybrids. Both genetic and agronomic studies indicate that new valuable
variation from exotic germplasm may be introduced into barley breeding
material.