Extensive research has been devoted to evaluating potential
genotype-environment interactions. However, plant breeders are still in
need of a simple way to describe how genotypes respond to different
locations and years. In an environmentally diverse state like Oregon,
significant genotype-environment interactions do occur The resulting lack
of association between actual and genotypic potential yield performance
makes it difficult to select genotypically superior lines. This study was
prompted to evaluate the extent of such an interaction and compare
various yield stability models.
A significant genotype-environment interaction encompassing lines,
environments, and years was discovered for each individual year analyzed
and for the combined analysis of 1992, 1994 and 1995, and 1989
through 1994. Most lines evaluated during 1992, 1994 and 1995 were
adapted to low yielding environments. However, two genotypes
(OR880172 and OR880525) exhibited broad adaptation. Stephens and
Mac Vicar were less adapted to the relatively high yielding Chambers site
than the other genotypes tested during 1992, 1994 and 1995 due to
Septoria tritici infections. The most stable genotypes during the combined
1992, 1994 and 1995 and 1989-1994 seasons were OR870831, Madsen
and OR8500933H. Gene was the most desirable genotype based on
stability and yield for both the combined 1992, 1994 and 1995 and 1989-1994 seasons. Due to an inability to adapt to higher yielding
environments, the cultivar Rohde was the least stable genotype during the
same combined periods. High and low temperatures and precipitation had
minor yet significant effects on yield responses at all three sites during
various periods identified.
Advanced winter wheat selections and cultivars were grown in
three diverse environments and compared over different time periods. Due
to trial design and the objective of identifying superior genotypes from a
set tested in target environments a combination of two methods, stability
variance and a selection index, emerged as the most appropriate
techniques. These approaches are considered the most appropriate
because they use the mean of the trial as a gauge for measuring stability. / Graduation date: 1997
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/34082 |
| Date | 09 May 1997 |
| Creators | Larson, Mark J., 1962- |
| Contributors | Kronstad, Warren E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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