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Molecular Plant Breeding 2013, Vol.5, No.7, 36
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Figure 3 Relationship pattern between wet gluten-protein ration
and protein content
This peculiar relationship of protein-gluten association
could also have altered certain other inter-related grain
components like gluten strength (sedimentation
volume), gluten quality (gluten index) and such
reports are available in literature (Drikvand et al.,
2013). To investigate it deeply, the pattern of
association among two traits was examined by scatter
diagram and polymer trend of order 2 was noted. Only
those relationships are presented where R
2
value was
higher ≥0.10. In wheat, there is hardly any quality
parameter which is strongly influenced by just one
component (Mohan et al., 2013a); therefore R
2
value of
≥0.10 in big populations (≥200 genotypes) cannot be
ignored. Gluten strength and gluten index are strongly
correlated. For high HMWGS, the relationships with
quality have been reported less strong (Weegels et al.,
1996).
In this study, relationship between wet gluten and
sedimentation volume was not very strong and the R
2
value was 0.05 and 0.01 in 5+10 and 2 12 wheats,
respectively. However, variation in the pattern could be
noticed between gluten strength with gluten index, two
strongly correlated grain qualities in wheat (Manthey et
al., 2000). Gluten index and sedimentation volume
were inter-related in this study as well but difference
lied in the magnitude of association (Figure 4).
Association between sedimentation volume and gluten
index was very strong in 5+10 group (R
2
: 0.49)
whereas in 2+12, this relationship was diluted (R
2
:
0.27). It was observed that incremental change brought
in gluten index through sedimentation volume was
sharp but started tapering at the higher levels. In 2+12
Figure 4 Relationship between gluten strength and gluten index
wheats, even though rate of increase in gluten index
was slow but it stayed consistent at different levels of
sedimentation volume. It illustrates that contribution of
gluten strength in flour much higher in 5+10 in
comparison to 2+12 wheats.
1.4 Influence on flour recovery
Flour extraction rate in Indian wheats is highly
influenced by grain hardness index, protein/ gluten
content and sedimentation volume (Mohan et al.,
2013c; Mohan and Gupta, 2014). Even though there
was hardly any difference in average flour yield of +10
and 2+12 wheats (68.8%) in this investigation,
variations were obvious in the response of wet gluten
and hardness of the grains (Figure 5). Wet gluten and
grain hardness index were found strongly associated
with flour yield in 2+12 wheats. In 5+10, contribution
of such traits was very limited and there was hardly any
trend. In 2+12 also, the response was good only up-to
certain threshold value which was 35ml in
sedimentation volume and 75 in grain hardness index.
Study demonstrated that flour recovery in 2+12 wheats
can be effectively enhanced through wet gluten and
grain hardness up-to certain limit. Such gains in flour
recovery cannot be harnessed in 2+12 wheats when wet
gluten content goes very high (≥35%) or the grain
becomes extremely hard (≥75).
Figure 5 Association of wet gluten and grain hardness with
flour recover
1.5 Relationship with product quality
Traditionally, protein and hardness are considered the
two most desirable attributes linked with dough
quality. When variations are found in relationship of
grain properties, product quality can also be affected.
Since wet gluten derived from per unit protein was