Rice Genomics and Genetics 2015, Vol.6, No.1, 1-5
2
family had five rows of 15 single plants each. Each
family had five rows of 15 single plants each. The
recommended agronomic practices were followed
throughout the crop growth period. Biometrical
observations were recorded from five single plants per
family per replication, randomly selected.
The collected data in each F
4
generation were
subjected to estimate the correlation and path analysis
as explained by Singh and Chaudhary (1985) where
grain yield/plant was kept as resultant variable and
other yield component characters as causal variables.
The zinc and iron content were determined by using
Atomic absorption spectrophotometer. All the
statistical analysis were done by using GENRES
statistical software.
1.1 Estimation of iron and zinc content:
The rice grain samples were air dried to 12%~14%
moisture content and hand hulled using palm dehusker,
finally the brown rice was obtained. Brown rice was
polished by using sand paper (No.100). The polished
rice grains were powdered and used for analysis. Half
a gram of powdered rice grain sample with 12 ml of
triple acid mixture (9:2:1 Nitric: Sulphuric: Perchloric
acid) was kept for overnight digestion. The digested
samples were kept on a hot plate till the solution turns
colourless. The extract was diluted to 50 ml and fed to
the Atomic Absorption Spectrophotometer. For the
measurement of iron, FeSO
4
was used as standard and
for zinc, the standard was ZnSO4
.
The concentrations
were expressed as parts per million (ppm).
2 Results and Discussion
2.1 ADT37×IR68144-3B-2-2-3
Grain iron content ranged from 3.420 ppm to
5.420mm in F
4
generation of ADT37×IR68144-
3B-2-2-3 Table 1. Days to fifty per cent flowering
(0.526), plant height (0.538) number of productive
tillers per plant (0.448), number of filled grains per
panicle (0.687), kernel breadth after cooking (0.376),
breadth wise expansion ratio (0.240) and grain zinc
content (0.344) exhibited positive and significant
correlation with grain yield Table 2. These findings
were supported by Nagesh et al. (2012) for number of
productive tillers per plant in F
1
and Kalaimaghal
(2011) reported positive and significant association
with yield for plant height, number of productive
tillers (both the generations), hundred grain weight
(both the generations), kernel length and kernel
breadth in F
2
population, iron content in F
2
of the
cross ADT37×IR68144-3B-2-2-3. In path analysis
number of filled grains per panicle had positive and
very high direct contribution with yield followed by
kernel L/B ratio, and zinc content table3.
In path
analysis iron content had negatively high direct effect
with yield. Purusothaman (2010) and Krishna et al.
(2008) also reported that zinc content and kernel L/B
ratio had positive direct effect with yield.
2.2 TRY (R) 2×Mapillaisamba
Grain zinc content ranged from 1.62-1.86 ppm in F
4
generation of TRY (R) 2×Mapillaisamba Table 1.
Days to fifty per cent flowering (0.878), plant
height (0.773), hundred grain weight (0.903) linear
elongation ratio (0.940), kernel L/B ratio (0.676)
and zinc content (0.584), exhibited significant and
positive correlation with yield in F
4
generation
table2. Plant height, hundred grain weight, zinc
content and kernel breadth and kernel breath after
cooking exhibited high to very high positive direct
effect with yield table 3. These results were
supported by Nagesh et al. (2012) for plant height in
hybrids, Kalaimaghal (2011) in F
2
, F
3
generation for
zinc content
,
Chakraborty et al. (2010) for hundred
grain weight and Krishna et al. (2008) for kernel
breadth. Linear elongation ratio had negative direct
effect due to the high indirect effect of kernel length,
kernel breadth after cooking, breadth wise
expansion ratio and iron content. Hence, selection
based on plant height, hundred grain weight, zinc
content and kernel breadth of this cross will be
useful for improvement in rice.
Table 1 Iron and zinc content in parents and cross cominations
Characters
ADT37 ×IR68144-3B-2-2-3
TRY (R) 2 × Mapillaisamba
Iron content in (ppm) parents
P
1
3.48~3.71
P
2
4.39~4.42
P
1
3.64~3.79
P
2
2.47~3.14
Iron content (ppm) in F
4
Generation 4.215
2.42~3.57
Zinc content (ppm) in parents
1.77~1.93
1.05~1.22
0.83~0.86
3.50~4.08
Zinc content in F
4
generation
0.18~1.45
1.62~1.86
