Schriften zu Genetischen Ressourcen - Genres

H. GRAUSGRUBER, H. BOINTNER, R. TUMPOLD and P. RUCKENBAUER
zone. As a result of these efforts Austrian spring barley cultivars were successfully
registered also in other European countries in the last decades.
In this study the genetic improvement in grain yield, yield components and agronomic
traits was determined over three seasons under the low-rainfall conditions of the
Pannonic climate zone.
Materials and methods
Experiments involving 24 genotypes (Tab. 1) were carried out over three seasons
(1999-2001). In seven trials the increase in grain yield, yield components and agronomic
traits achieved by barley breeding during the period of 1832 to 1996 was estimated.
The field trials were carried out in Groß Enzersdorf, Raasdorf and Vienna under
natural conditions. No fungicides were applied to control diseases, and tall
genotypes were not supported in order to prevent yield losses.
Diseases, time to heading and plant height were recorded during the vegetation period.
From three trials, 10 to 15 single plants from inside the plots were analysed for
the yield components number of spikes per plant, number of kernels per spike and
thousand kernel weight (TKW). In four trials kernel number per square meter (KN)
was deduced from the relationship between grain yield (GY) and the yield components:
GY = KN * TKW. Subsequently the number of kernels per plant and yield per
plant was deduced from the germinated seeds per square meter. Harvested grains
were analysed for test weight and % protein and % malt extract (fine grind). The latter
quality traits were determined using NIRS. An overall resistance score was calculated
according to OBERFORSTER (1997), however, modified in a way that the score
was calculated for each replicate and not over the replicates for the respective trials.
Results
No significant improvement over the period of more than 130 years was observed for
time to heading and test weight. For the single yield components, genetic improvement
was generally observed only since the 1960s (Tab. 2). Almost all cultivars
which were originally selected for regions with higher rainfall, e.g., Tuxer, ‘Fisser’ and
‘Martha’, performed below the observed trends over time (Fig. 1a).
Correlation analyses between the yield components revealed for all three seasons
that yield per plant was primarily a function of the number of spikes per plant, followed
by TKW. The number of kernels per spike was only of less influence. Hence,
the genetic improvement in grain yield was above all due to the ability of modern cultivars
to produce more spikes per unit area.
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