Basic HTML Version
Plant Gene and Trait, 2013, Vol.4, No.3, 9
-
16
http://pgt.sophiapublisher.com
13
Figure 1 Genotypic correlation co-efficient for different
characters on grain yield under different population density
levels in grain amaranthus
Note: DFF: Days to 50 per cent flowering; LAF: Leaf area at
50 per cent flowering; LI: Length of the primary inflorescence;
DI: Diameter of the inflorescence; FWI: Fresh weight of the
inflorescence; NR: Number of rachis per inflorescence; LR:
Length of the rachis per inflorescence; NSB: Number of
secondary branches per inflorescence; TCC: Total carbohy-
drates content; PC: Protein content
The genotypic correlation coefficients of component
traits with grain yield per plot were partitioned into
direct and indirect effects through path coefficient
analysis (Tables 5~8). In the present study the direct
effects of all the component traits on grain yield
showed high fluctuation in direction as well as in
magnitude under four plant density levels. The traits
viz.,
fresh weight of the inflorescence, length of the
primary inflorescence and number of secondary
branches per inflorescence which were identified as
yield attributing traits based on correlation and
intercorrelation studies, fresh weight of the
inflorescence was found to be the most important
contributing trait as it significantly improves the grain
yield per plant in all the four plant density levels. In
path analysis, as in case of correlation studies, these
traits had very high positive direct effects on grain
yield in all the plant density levels (Figure 2). In
addition to that, leaf area at 50 per cent flowering,
length of the primary inflorescence and number of
secondary branches per inflorescence also identified
as the most important yield contributing traits from
the path analysis in all the four plant density levels.
The length of the rachis per inflorescence had high
positive direct effect on grain yield per plant in all the
density levels except very high density. These results
confirm that the fresh weight of the inflorescence
should be given prime importance in selection
programme for improvement of grain yield in grain
amaranthus irrespective of plant density levels. The
positive direct effect was exhibited by plant height in
high and normal plant densities, whereas in very high
and low plant density levels this trait showed high and
very high negative direct effects. The other yield
contributing trait diameter of the
inflorescence had
direct positive effect on grain yield in all density
levels except high density level (D
2
). Total carbohy-
drates and protein content showed high positive direct
effects on grain yield in very high density and also
protein content recorded low positive direct effect
under low plant density. In the present study, days to
50 per cent flowering and number of rachis per
inflorescence recorded negative direct effects in all the
density levels. Total carbohydrates recorded high and
Figure 2 Direct and indirect effects of different characters on
grain yield under different plant density levels in grain
amaranthus
Note: DFF: Days to 50 per cent flowering; LAF: Leaf area at
50 per cent flowering; LI: Length of the primary inflorescence;
DI: Diameter of the inflorescence; FWI: Fresh weight of the
inflorescence; NR: Number of rachis per inflorescence; LR:
Length of the rachis per inflorescence; NSB: Number of
secondary branches per inflorescence; TCC: Total carbohy-
drates content; PC: Protein content