Page 5 - Triticeae Genomics and Genetics

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Triticeae Genomics and Genetics 2014, Vol.5, No.1, 1-6
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2
methods for the improvement of the barley. A lot of
information on nature and relative magnitude of
genetic components of variation (additive and
dominance) have been generated by generation mean
analysis, but literature on barley in respect of fixable
and non fixable gene effect is meager. Therefore, the
present study was planned to investigate genetics of
days to ear emergence, days to maturity, no. of
effective tillers/plant, and weight of grains/main spike
(g), no. of grain/spike and 1000-grain weight (g) by
using six-generations of the three crosses under
normal and saline sodic soil conditions.
1 Materials and Methods
The inheritance of genetic parameters were studies
using six generations of three crosses of barley namely
DL 88 × K 560, K 603 × Azad, RD 2552 × NDB 1020
by applying generation mean analysis. Six generations
of these crosses viz., P
1
, P
2
, F
1
, F
2
, BC
1
and BC
2
were
grown separately in Randomized Block Design with
three replications in two environments, one sown in
normal soil and other sown in saline sodic soil during
the same season. Planting were done in row of 3 m
long. Row to row distance was kept 25 cm apart. The
parent (P
1
and P
2
) and F
1
s were sown in 2 rows, while
back cross generations and F
2
generation were sown in
5 and 6 respectively 6 rows of 3 m length. The
experiment was carried out during the 2011-2012 at
KVK Chhatarpur Farm, J.N.K.V.V Jabalpur Madhya
Pradesh. Fifteen random plants in parent and F
1
generation, 60 plants in F
2
generation and 45 plants in
back cross generations were used for recording
observations for six traits in each replication. The
analysis of variance for RBD was carried out
following Panse and Sukhatme (1967). The scaling
test was performed to test the estimates of
six-parameter model using the digenic epistatic model
of Hayman, 1958. The scaling tests ‘A’, ‘B’ ‘C’ and D
was used to test the adequacy of the
additive-dominance model.
2 Results and Discussion
Results of the scaling tests revealed that out of four
scaling tests one or two scales were found significant
in all the three crosses for most of the characters.
Therefore, the six-parameter model to detect gene
effects was applied in all the characters. The estimates
of m, d, h, i, j and l of six parameter model for all the
characters are presented in Table 1.Mean data and
standard error of the six generations with five crosses
for nine traits were calculated. The earliness in ear
emergence and days to maturity along with dwarf
stature have been considered as desirable traits in
barley as it is mainly grown as a rainfed crop. Crosses
found superior to their respective parents was RD
2552 × NDB 1020 for effective tillers/plant
(10.57±0.39) .The crosses of DL 88 × K 560, RD
2552 × NDB 1020, recorded maximum number of
grains/main spike (64.43±0.39 and 92.03±0.46
respectively). The crosses RD 2552 × NDB 1020
registered maximum 1000 grain weight (40.20±0.36)
while DL 88 × K 560 gave maximum grain yield/plant
(26.97±0.33 g).
A simple additive-dominance model was inadequate
as inferred from the significance of all traits. The
additive, dominance and epistatic types of gene
interaction in each cross for different traits were found
different from each other (Table 1). Comparison of
estimates of gene effect with respect to magnitude as
well as significance reveled that additive (d) was of
greater importance than to the dominance (h) gene
effects for no. of effective tillers/plant, length of main
spike and grain yield/plant in the RD 2552 × NDB
1020 cross. Thus, selection for no. of effective
tillers/plant and 1000-grain weight will be effective in
early segregating generations. Both additive (d) and
dominance (h) effects were pronounced in crosses
DL88 × K560 for weight of grains/spike, grain
yield/plant and RD 2552 × NDB 1020 for no. of
grains/spike.
The dominance (h) effect was more important than
additive gene effects (d) in the inheritance of
1000-grain weight in the DL88 × K560 cross. The
genetic effects for these characters suggested that
selection for these characters will not be effective in
segregating generations. Higher magnitude of
dominance (h) component than the additive (d)
component suggested that the parents involved in the
crosses were in dispersion phase and dominance
component was more important for these characters.
Vimal and Vishwakarma (1999) also reported
predominance of non-additive gene action for yield
and yield components in barley.
Estimates of additive × additive (i), additive ×
dominance (j) and dominance × dominance (l)
interactions indicated that the additive × additive (i)