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

fhe possibility <strong>of</strong> obtaining singLe genotJrpes wíth
siÌnultaneous inprovements in two or more characters was not
examined .
Selection <strong>of</strong> higher yielding lines should have been
possíb1e in C-70-1 aîd, C-?O-2, fieritabitlty for yietd was
moderatel-y high in C-?O-Z, $ras at a useful level in e-?O-L,
and in both there was significant genetÍc variance. The low
level <strong>of</strong> heritabil_íty in C-lO-j lndicated that, through the
experimental procedure used, improvernent over Bonanza could
not be made. However, despÍte C-?O-3 having the snaLlest
sample size (4I lines compared to lOj and. B?), the range <strong>of</strong>
lÍne mean yieLds was the greatest. In fact C-?O-3 contained
the highest yielding line in the study on a nean basís"
Therefore, lt appears reasonable that more thorough testing
<strong>of</strong> this population would be justified to ascertaín itrs
potential despite the low heritabllÍty estirnated for yie1d.
A.n underlying objective <strong>of</strong> this study was to determine
L82
whether high yietding short strawed genotype s could be select-
ed fron these populatl_ons. The results showed trends in_
dicating that yield improvements could be made in all <strong>height</strong>
clâsses within each populatl_on. fhe highest yielding llnes
were in the ta1l and intermediate <strong>height</strong> categories. Never_
theless, as evidenced by CZO3O11, the possibility <strong>of</strong> prod-
uclng significantly shorter material apparently equal Ín
yietd to the control diti exist.
îhe low number <strong>of</strong> semi-dwarf lines involved was a draw-
back Ín the present study. This, particularly in C-lO-2,