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There were no variation among pure cultures as well as in
mixtures for ear length. This character was, therefore, not
taken up for further analysis. For number of tillers per
meter row length there were highly significant differences
for pure cultures as well as for the mixtures. The range for
parents was from 85.7 (ML-323) to 147.0 (ML-378) whereas for
mixture it ranged from 81.7 (ML-246+ML-419) to 137.3
(ML-270+ML-293). Although the magnitude of mean squares due
to pure cultures is much larger than that due to mixture the
variation in the latter appeared to be larger. In the pure
culture group one of the lines viz. ML-328 had exceptionally
high tiller number and may have contributed to the
variation. Otherwise the variation in mixture as a group
seems to be more. This is encouraging because tiller number
is one of the primary components of yield and if positively
interacting genotypes could be spotted out these would
result in increase in grain yield.
There were significant differences among progenies for seed
size. The differences due to pure cultures, mixtures and the
contrast between the two groups were also highly
significant. For pure cultures the seed size varied from
24.8 g for ML-328 g to 35.5 g for ML-270. The corresponding
range in case of mixtures was from 25.0 g (ML-293+ML-328) to
34.2 g (ML-267+ML-270). The general trend appears that when
two parents with almost similar seed size are mixed together
the mixture also has the seed size in the same range. For
instance ML-246, ML-267, ML-319 and ML-326 have a seed size
of 29.1, 28.8 and 28.9 respectively. The mixtures
ML-246+ML-267, ML-246+ML-319, ML-246+ML-326, ML-267+ML-319,
ML-267+ML-326 and ML-319+ML-326 had a seed size of 28,9,
29.3, 30.6, 29.6, 28.4 and 30.3 g respectively. Similarly,
when two lines (ML-270 and ML-412) with bold seeds are grown
in a mixture it results into bolder seeds. It is encouraging
to note that the seed size is not reduced at least, even if
only one of the parents is bold seeded in the mixture.
For grain yield the differences were highly significant for
pure culture and the comparison pure culture vs mixtures.
The range for pure cultures for grain yield from 500.0
(ML-328) to 1243.3 (ML-410). The corresponding range for the
mixture was from 623.3 (ML-246+ML-293) to 1383.3
(ML-323+ML-412). Both the lower and the upper yield levels
are higher in case of mixtures as compared with the pure
cultures. It is, however, not possible to establish to
definite trend between the pure cultures and mixtures.
Although ML-323+ML-412 and ML-412+ML-419 two top yielding
mixtures included one of the highest yielding pure cultures
(ML-412) it did not maintain the high performance in all
cases. On the contrary, however, wherever one of the two
poorest yielding lines (ML-246 and ML-328) were present the
mixture resulted into relatively lower yield level. It is
thus clear that for obtaining good yield in a multiline the
'nicking ability' even of the high-yielding components must
be high. The usefulness of the studies like the present one
for plant height and seed size has already been brought out
by JAIN & MOSHA (1974).
Table 2. Progeny means for
different charactrs
Combining ability analysis
The analysis of variance (Table 1)
indicated that the variance due to gca was highly
significant for all the characters studied. However, sca
variance was important in case of days to 50 per cent
heading, tiller number, seed size and grain yield. The ratio
between the two variances ranged from 1.46 for seed size to
96.01 for days to 50 per cent heading. This indicated that
the additive effects were much more important in the
material and it may be possible to select for better general
combining ability in case of all the characters studied.
The estimates of general combining ability effects for
different characters in respect of the parents are given in
Table 3.
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