Effects of reduced plant height on breeding requirements and ...

association with test weight can be partially accounted for
in a sinilar fashion, but the main explanation cones from
the assoeiation <strong>of</strong> kernel weight and plumpne ss, since,
plump kernels have an increased width to length ratio,
therefore pack more tightly and have a higher weight per
unit volume. Since the plunper kernels in thÍs naterial
were the heavier kernels, the association <strong>of</strong> kernel weight
and test vreÍght would be expected.
the correlation <strong>of</strong> kernel weight with days in post-
anthesis probably reflects the fact that the weight <strong>of</strong> the
kernels develops during this peri.od. The negatrve reration-
ship wíth heading date exl_sted. because, the earller a geno_
type fJ.owered in a finite growing season, the longer was
it's grain deve lopment time.
Fhe posítLve relatÍonship between kernel weight and
lodging was due to the type <strong>of</strong> 1odglng measured and the
nature <strong>of</strong> the material studied.
Negatíve associations existed between kernel weight
and alphå-amylase and soluble amino-nitrogen Levels, in
particular in C-?0-Ì and C-?O-2, suggesting that lines with
heavÍer kernels become heavier via inereased carbohydrate
deposLtion ât the expense <strong>of</strong> nitrogenous compounds. llow_
ever, the significant posÍtive assocíatLon between kernel
weight and percent barley nÍtrogen in C-?O-2 indicated that,
at least in that popul_ation, nitrogen depositíon was not
hampered in the heavier kernel lines, sugge sting that the
yleld to nitrogen negatj.ve relationshÍp nnay not be either
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