Cross prediction studies on spring barley
The genetical and environmental control of a number of characters
of agronomic importance in barley has been investigated by triple test
cross (TTC) and linear model-fitting analyses.
Additive and dominance genetic effects are observed for height,
maturity, yield and yield component characters with the exception of
tiller number, which was found to be almost totally controlled by
environmental factors. Epistasis was found to be important only for
grain number, although it was observed in other characters (notably neck
Other analyses on the same data set have also been made to detect
the presence of genotype x environment interactions and linkage in the
above characteristics, together with phenotypic and genotypic
correlations between them.
Only height at harvest and 1000 grain weight appeared to have
potential for early generation selection. As a result, efficient
prediction of the potential of a particular cross for the majority of
characters of agronomic importance is shown to be necessary and
The second part of this work involved testing the effectiveness of
cross-prediction methods based on the results of the genetical analyses.
It is shown that the potential of a cross to produce superior inbred
lines can be successfully predicted from TTC and model-fitting analyses.
The prediction methods have been shown to be successful in
identifying the cross from a number of crosses with the greatest
potential in respect of both single characters and pairs of characters.
It is shown that yield itself can be studied successfully in this way,
as well as those characters with high heritability such as height and
1000 grain weight. Furthermore it is shown that an estimate of the
additive genetic variance necessary for making the predictions, of
similar accuracy to that obtained from the TTC, can be Je<-ive