3.1. Correlation Coefficients of Seed and Oil Yield per Plant with other Traits at Two Locations
3.1.1. Correlation of Seed and Oil Yield
Estimates of genotypic and phenotypic correlation coefficients at Holeta and Kulumsa environments are shown in Tables 2 and 3, respectively. The analysis of correlations in each location showed that genotypic correlation coefficients were generally higher than their corresponding phenotypic correlations indicating strong hereditary association among the traits due to genetic factors such as linkage and/or pleiotropic effect enabling consistent performance across wide range of environments as described by Waitt and Levin [36]. Seed and oil yield are very complex characters which are governed by polygenes and the result of numerous simple characters presumably showing considerable variations from one environment to another [30]. The correlation between the traits may be due to linkage or pleiotropy [2] or environment [1]. Similarly, a narrow difference between phenotypic and genotypic correlation coefficient was obtained for almost all the pairs of characters studied showing that masking or modifying effects of the environment was little demonstrating that the presence of an inherent association among these characters. Similar results were reported in linseed studies of Wakjira [37], Tadesse [33], Mulusew [19] and Worku [38].
Table 2
Phenotypic correlation coefficient between 17 morphoagronomic and oil traits of 126 linseed genotypes above diagonal at Holeta and below diagonal at Kulumsa in 2019/20
|
DF
|
DM
|
PH
|
PB
|
SB
|
NC
|
NSC
|
TSW
|
BYp
|
DF
|
|
0.87**
|
-0.79**
|
-0.52**
|
-0.14
|
-0.57**
|
-0.63**
|
-0.67**
|
-0.64**
|
DM
|
0.87**
|
|
-0.72**
|
-0.48**
|
-0.12
|
-0.61**
|
-0.62**
|
-0.76**
|
-0.60**
|
PH
|
-0.79**
|
-0.72**
|
|
0.60**
|
0.12
|
0.56**
|
0.70**
|
0.70**
|
0.64**
|
PB
|
-0.52**
|
-0.48**
|
0.60**
|
|
0.23**
|
0.52**
|
0.67**
|
0.64**
|
0.65**
|
SB
|
-0.16
|
-0.13
|
0.12
|
0.23**
|
|
0.27**
|
0.26**
|
0.23**
|
0.16
|
NC
|
-0.57**
|
-0.61**
|
0.56**
|
0.52**
|
0.27**
|
|
0.62**
|
0.68**
|
0.54**
|
NSC
|
-0.63**
|
-0.62**
|
0.70**
|
0.67**
|
0.27**
|
0.62**
|
|
0.76**
|
0.82**
|
TSW
|
-0.65**
|
-0.72**
|
0.66**
|
0.62**
|
0.23**
|
0.62**
|
0.74**
|
|
0.68**
|
BYP
|
-0.64**
|
-0.60**
|
0.64**
|
0.65**
|
0.17
|
0.54**
|
0.82**
|
0.66**
|
|
HI
|
0.33**
|
0.31**
|
-0.32**
|
-0.33**
|
0.1
|
-0.22*
|
-0.47**
|
-0.31**
|
-0.80**
|
CRB
|
0.09
|
0.03
|
-0.02
|
-0.04
|
-0.09
|
-0.04
|
-0.09
|
-0.07
|
-0.06
|
PRT
|
-0.01
|
0.06
|
-0.02
|
-0.03
|
0.04
|
0.02
|
-0.03
|
-0.01
|
-0.03
|
OA
|
0.07
|
0.12
|
-0.05
|
0.06
|
-0.01
|
-0.01
|
-0.03
|
0.01
|
-0.03
|
LN
|
0.1
|
0.05
|
-0.08
|
-0.14
|
-0.03
|
-0.04
|
-0.13
|
-0.07
|
-0.13
|
LNN
|
-0.03
|
-0.01
|
-0.01
|
-0.01
|
0.11
|
-0.01
|
0.01
|
0.07
|
0.01
|
OYP
|
-0.70**
|
-0.70**
|
0.71**
|
0.67**
|
0.27**
|
0.63**
|
0.83**
|
0.77**
|
0.80**
|
SYP
|
-0.77**
|
-0.78**
|
0.80**
|
0.75**
|
0.26**
|
0.71**
|
0.89**
|
0.84**
|
0.86**
|
Tabular r = 0.18 at 5%; r = 0.23 at 1% |
*and **: significant at p < 0.05 and p < 0.01 probability levels, respectively. DF = days to 50% flowering, DM = days to maturity, PH (cm) = plant height, PB = number of primary branches, SB = number of secondary branches, NC = number of capsules per plant, NSC = number of seeds per capsule, TSW (g) = thousand seed weight, BYP (kg) = biological yield per plant, HI (%) = harvest index, CRB (%) = carbohydrate, PRT (%) = crude protein, OA (%) = oleic acid, LN (%) = linoleic acid, LNN (%) = linolenic acid, OYP (%) = oil yield per plant and SYP (g) = seed yield per plant. |
Table 2
|
HI
|
CRB
|
PRT
|
OA
|
LN
|
LNN
|
OYP
|
Syp
|
DF
|
0.33**
|
0.07
|
0.01
|
0.04
|
0.07
|
-0.07
|
-0.69**
|
-0.77**
|
DM
|
0.30**
|
0.03
|
0.09
|
0.1
|
0.04
|
-0.07
|
-0.70**
|
-0.78**
|
PH
|
-0.31**
|
-0.03
|
0.01
|
-0.04
|
-0.06
|
0.02
|
0.70**
|
0.80**
|
PB
|
-0.33**
|
-0.06
|
-0.06
|
0.07
|
-0.14
|
0.01
|
0.68**
|
0.75**
|
SB
|
0.11
|
-0.05
|
0.05
|
0.01
|
-0.02
|
0.09
|
0.25**
|
0.25**
|
NC
|
-0.21*
|
-0.05
|
0.01
|
-0.01
|
-0.02
|
0.03
|
0.63**
|
0.71**
|
NSC
|
-0.47**
|
-0.1
|
-0.04
|
-0.02
|
-0.11
|
0.07
|
0.82**
|
0.89**
|
TSW
|
-0.31**
|
-0.06
|
-0.06
|
0.01
|
-0.07
|
0.11
|
0.79**
|
0.87**
|
BYP
|
-0.80**
|
-0.06
|
-0.04
|
-0.02
|
-0.11
|
0.04
|
0.79**
|
0.86**
|
HI
|
|
0.01
|
0.02
|
0.01
|
0.07
|
0.01
|
0.42**
|
-0.46**
|
CRB
|
0.02
|
|
-0.63**
|
-0.12
|
0.59**
|
-0.69**
|
-0.46**
|
-0.06
|
PRT
|
0.03
|
-0.68**
|
|
0.09
|
-0.24**
|
0.34**
|
0.13
|
-0.06
|
OA
|
0.02
|
-0.11
|
0.1
|
|
-0.14
|
0.09
|
0.06
|
0.02
|
LN
|
0.08
|
0.59**
|
-0.28**
|
-0.12
|
|
-0.28**
|
-0.36**
|
-0.11
|
LNN
|
0.02
|
-0.66**
|
0.32**
|
0.09
|
-0.30**
|
|
0.35**
|
0.06
|
OYP
|
-0.43**
|
-0.46**
|
0.18*
|
0.03
|
-0.37**
|
0.30**
|
|
0.90**
|
SYP
|
-0.46**
|
-0.06
|
-0.03
|
0.01
|
-0.12
|
0.02
|
0.91**
|
|
Tabular r = 0.18 at 5%; r = 0.23 at 1% |
*and **: significant at p < 0.05 and p < 0.01 probability levels, respectively. DF = days to 50% flowering, DM = days to maturity, PH (cm) = plant height, PB = number of primary branches, SB = number of secondary branches, NC = number of capsules per plant, NSC = number of seeds per capsule, TSW (g) = thousand seed weight, BYP (kg) = biological yield per plant, HI (%) = harvest index, CRB (%) = carbohydrate, PRT (%) = crude protein, OA (%) = oleic acid, LN (%) = linoleic acid, LNN (%) = linolenic acid, OYP (%) = oil yield per plant and SYP (g) = seed yield per plant. |
Table 3
Genotypic correlation coefficient between 17 morphoagronomic and oil traits of 126 linseed genotypes above diagonal at Holeta and below diagonal at Kulumsa in 2019/20
|
DF
|
DM
|
PH
|
PB
|
SB
|
NC
|
NSC
|
TSW
|
BYp
|
DF
|
|
0.91**
|
-0.87**
|
-0.61**
|
-0.15
|
-0.66**
|
-0.68**
|
-0.74**
|
-0.71**
|
DM
|
0.90**
|
|
-0.81**
|
-0.54**
|
-0.13
|
-0.67**
|
-0.66**
|
-0.80**
|
-0.65**
|
PH
|
-0.86**
|
-0.81**
|
|
0.73**
|
0.15
|
0.70**
|
0.81**
|
0.83**
|
0.76**
|
PB
|
-0.60**
|
-0.54**
|
0.73**
|
|
0.26**
|
0.62**
|
0.78**
|
0.71**
|
0.74**
|
SB
|
-0.16*
|
-0.13
|
0.15
|
0.26**
|
|
0.30**
|
0.29**
|
0.24**
|
0.19*
|
NC
|
-0.65**
|
-0.67**
|
0.70**
|
0.62**
|
0.30**
|
|
0.67**
|
0.76**
|
0.61**
|
NSC
|
-0.68**
|
-0.66**
|
0.82**
|
0.77**
|
0.29**
|
0.67**
|
|
0.83**
|
0.89**
|
TSW
|
-0.73**
|
-0.77**
|
0.80**
|
0.69**
|
0.25**
|
0.71**
|
0.82**
|
|
0.78**
|
BYP
|
-0.71**
|
-0.65**
|
0.76**
|
0.74**
|
0.20*
|
0.61**
|
0.89**
|
0.77**
|
|
HI
|
0.42**
|
0.39**
|
-0.41**
|
-0.44**
|
0.1
|
-0.29**
|
-0.57**
|
-0.44**
|
-0.82**
|
CRB
|
0.09
|
0.02
|
-0.05
|
-0.02
|
-0.1
|
-0.04
|
-0.09
|
-0.07
|
-0.06
|
PRT
|
0.01
|
0.08
|
0.01
|
-0.06
|
0.05
|
0.02
|
-0.04
|
-0.03
|
-0.04
|
OA
|
0.07
|
0.12
|
-0.05
|
0.06
|
0.01
|
-0.02
|
-0.04
|
0.01
|
-0.04
|
LN
|
0.1
|
0.04
|
-0.08
|
-0.15
|
-0.04
|
-0.04
|
-0.13
|
-0.08
|
-0.14
|
LNN
|
-0.05
|
-0.02
|
0.01
|
-0.03
|
0.13
|
-0.04
|
0.03
|
0.09
|
0.02
|
OYP
|
-0.74**
|
-0.71**
|
0.80**
|
0.74**
|
0.29**
|
0.66**
|
0.86**
|
0.83**
|
0.83**
|
SYP
|
-0.80**
|
-0.80**
|
0.90**
|
0.82**
|
0.27**
|
0.75**
|
0.93**
|
0.90**
|
0.90**
|
Tabular r = 0.18 at 5%; r = 0.23 at 1% |
*and **: significant at p < 0.05 and p < 0.01 probability levels, respectively. DF = days to 50% flowering, DM = days to maturity, PH (cm) = plant height, PB = number of primary branches, SB = number of secondary branches, NC = number of capsules per plant, NSC = number of seeds per capsule, TSW (g) = thousand seed weight, BYP (kg) = biological yield per plant, HI (%) = harvest index, CRB (%) = carbohydrate, PRT (%) = crude protein, OA (%) = oleic acid, LN (%) = linoleic acid, LNN (%) = linolenic acid, OYP (%) = oil yield per plant and SYP (g) = seed yield per plant. |
Table 3
|
HI
|
CRB
|
PRT
|
OA
|
LN
|
LNN
|
OYP
|
Syp
|
DF
|
0.42**
|
0.07
|
0.01
|
0.05
|
0.08
|
-0.08
|
-0.73**
|
-0.81**
|
DM
|
0.39**
|
0.03
|
0.08
|
0.11
|
0.04
|
-0.09
|
-0.71**
|
-0.80**
|
PH
|
-0.41**
|
-0.04
|
-0.01
|
-0.03
|
-0.07
|
0.03
|
0.79**
|
0.89**
|
PB
|
-0.44**
|
-0.06
|
-0.05
|
0.09
|
-0.15
|
-0.01
|
0.75**
|
0.82**
|
SB
|
0.11
|
-0.05
|
0.05
|
0.02
|
-0.02
|
0.1
|
0.27**
|
0.27**
|
NC
|
-0.29**
|
-0.04
|
0.02
|
0.02
|
-0.03
|
0.01
|
0.66**
|
0.75**
|
NSC
|
-0.57**
|
-0.09
|
-0.04
|
-0.02
|
-0.12
|
0.07
|
0.86**
|
0.93**
|
TSW
|
-0.46**
|
-0.07
|
-0.03
|
0.02
|
-0.06
|
0.13
|
0.83**
|
0.92**
|
BYP
|
-0.81**
|
-0.06
|
-0.04
|
-0.02
|
-0.12
|
0.06
|
0.83**
|
0.90**
|
HI
|
|
0.03
|
0.03
|
0.01
|
0.08
|
-0.02
|
-0.51**
|
-0.55**
|
CRB
|
0.02
|
|
-0.65**
|
-0.13
|
0.62**
|
-0.78**
|
-0.46**
|
-0.06
|
PRT
|
0.1
|
-0.70**
|
|
0.1
|
-0.26**
|
0.42**
|
0.16
|
-0.05
|
OA
|
-0.55**
|
-0.11
|
0.1
|
|
-0.14
|
0.12
|
0.06
|
0.02
|
LN
|
0.1
|
0.61**
|
-0.27**
|
-0.12
|
|
-0.34**
|
-0.38**
|
-0.11
|
LNN
|
0.01
|
-0.74**
|
0.38**
|
0.1
|
-0.34**
|
|
0.38**
|
0.06
|
OYP
|
-0.51**
|
-0.45**
|
0.18*
|
0.03
|
-0.39**
|
0.33**
|
|
0.91**
|
SYP
|
-0.55**
|
-0.05
|
-0.05
|
0.01
|
-0.12
|
0.02
|
0.91**
|
|
Tabular r = 0.18 at 5%; r = 0.23 at 1% |
*and **: significant at p < 0.05 and p < 0.01 probability levels, respectively. DF = days to 50% flowering, DM = days to maturity, PH (cm) = plant height, PB = number of primary branches, SB = number of secondary branches, NC = number of capsules per plant, NSC = number of seeds per capsule, TSW (g) = thousand seed weight, BYP (kg) = biological yield per plant, HI (%) = harvest index, CRB (%) = carbohydrate, PRT (%) = crude protein, OA (%) = oleic acid, LN (%) = linoleic acid, LNN (%) = linolenic acid, OYP (%) = oil yield per plant and SYP (g) = seed yield per plant. |
3.1.2. Correlation among Seed and Oil Yield and Yield Components
Genotypic and phenotypic correlations for all possible combinations of traits at phenotypic and genotypic correlation estimates between seed yield per plant and the various characters at Holeta and Kulumsa were presented in Table 2 and Table 3, respectively. At genotypic and phenotypic levels seed yield per plant had highly significant positive correlations with plant height, number of primary braches per plant, number of secondary braches per plant, number of capsules per plant, number of seeds per capsule, thousand seed weight, biological yield per plant and oil yield per plant, indicating that selection based on these parameters would considerably enhance seed yield per plant. These results partially agree with the finding of Tadesse [33] and Worku [38].
At both locations besides seed yield per plant, the oil yield per plant showed a highly significant positive correlation at genotypic and phenotypic levels with plant height, number of primary branches per plant, number of secondary branches per plant, number of capsules per plant, number of seeds per capsule, thousand seed weight, biological yield per plant and linolenic fatty acid, implying that selection based on these eight characters could enhance the oil yield per plant, which ultimately would lead to an increase in seed yield per plant. This result agrees with the finding of Wakjira [37], Tadesse. [33], Gauraha and Rao [10] and Mulusew [19], Reddy [27], Kumar [17], Kaur [16] and Patial [23].
Seed yield per plant had highly significant negative correlations at phenotypic and genotypic levels at both locations with days to flowering, days to maturity, and harvest index, suggesting that early maturity would favorably enhance seed yield per plant. This result agree with the finding of and Kumar [17], Kaur et al. [16] and Patial [23] and partially agree with findings of Tadesse [33] and Worku [38].
At both locations oil yield per plant had positive and highly significant phenotypic and genotypic correlation coefficients with plant height, number of primary branches, number of secondary branches, number of capsules per plant, number of seeds per capsule, thousand seed weight, biological yield per plant, linolenic fatty acid and seed yield per plant, indicating that selection based on these parameters would considerably enhance oil yield per plant. Crude protein content had positive significant phenotypic and genotypic correlation coefficient with oil yield per plant at Kulumsa, implying that selection based on crude protein content using phenotypic and genotypic correlation at Kulumsa could enhance the oil yield per plant. This result agrees with the finding of Wakjira [37] Gauraha and Rao [10] and Reddy [27], Mulusew [19], Kumar [17], Kaur [16] and Patial [23].
Besides oil yield per plant, seed yield per plant showed a highly significant positive correlation at genotypic and phenotypic levels with plant height, number of primary braches per plant, number of secondary braches per plant, number of capsules per plant, number of seeds per capsule, thousand seed weight and biological yield per plant, implying that selection based on these characters could enhance the seed yield per plant, which ultimately would lead to an increase in oil yield per plant. This result agrees with the finding of Gauraha and Rao [10], Reddy [27], Kumar [17], Kaur [16] and Patial [23].
Days to 50% flowering, days to maturity, harvest index, carbohydrate and linoleic fatty acid content had negative and highly significant phenotypic and genotypic correlation coefficients with oil yield per plant at both locations, suggesting that reduced linoleic fatty acid would favorably enhance oil yield per plant. This result agrees with the finding of Wakjira [37] and Mulusew [19].
At both locations, among all fatty acids, linoleic acid showed a highly significant negative association with linolenic acid at phenotypic and genotypic levels. This negative correlation of linolenic acid with linoleic acid can be best understood by the fatty acid biosynthesis pathway. You [39] found that both linoleic and linolenic acids have a common biosynthesis pathway, so one can increase at the cost of the other. Similar findings were also reported by Bayrak [3] and Pali & Mehta [21]. The results obtained in the present study indicate that high oil yield per plant will result in high linolenic acid and reduce linoleic acids. However, Pali & Mehta[21] suggested that an increase in oil yield per plant will lead to an increase in linolenic acid. Bayrak [3] and Bhatty [4] also observed a negative association of linoleic acid with linolenic acid. Considering the obtained results, the present study suggests that selection to increase oil yield per plant would not affect linseed oil quality, since selection does not affect total fatty acid compositions, despite the noticeable changes in different fatty acids.
3.2 The Phenotypic Path Coefficient Analysis of Seed Yield per Plant at Holeta and Kulumsa
Seed yield per plant was the dependent variable while other evaluated morphoagronomic traits, oil yield and fatty acid contents which are significantly correlated at phenotypic level were considered as independent variables. Direct and indirect effects of these components were determined on seed yield per plant and their contributions in each of the two environments are shown in Table 4. The path coefficient analysis at phenotypic level revealed at Holeta and Kulumsa, respectively that biological yield per plant (0.629 and 0.627) had the highest positive direct effect on seed yield per plant. Similarly, biological yield per plant had highly significant and positive correlations (rp= 0.86**, rp= 0.86**) with seed yield per plant in each location (Holeta and Kulumsa), respectively at phenotypic level, indicating a direct selection through biological yield per plant will be effective in order to improve seed yield per plant of linseed. These results are in agreement with the findings of Tariq [34]; Paul [25] for biological yield per plant and partially agree with the findings of Tadesse [33] for harvest index and biomass yield.
Table 4. Direct (bold and underlined) and indirect effects (off diagonal) of traits on seed yield per plant at phenotypic level at two location in 2019/20
Location
|
Trait
|
DF
|
DM
|
PH
|
PB
|
SB
|
NC
|
NSC
|
TSW
|
BYP
|
HI
|
OYP
|
SYP rp
|
Holeta
|
DF
|
0.026
|
-0.119
|
-0.071
|
-0.034
|
0.003
|
-0.025
|
-0.061
|
-0.103
|
-0.400
|
0.095
|
-0.082
|
-0.77**
|
Kulumsa
|
|
0.050
|
-0.145
|
-0.077
|
-0.037
|
0.003
|
-0.032
|
-0.062
|
-0.072
|
-0.399
|
0.096
|
-0.094
|
-0.77**
|
Holeta
|
DM
|
0.022
|
-0.136
|
-0.064
|
-0.031
|
0.002
|
-0.027
|
-0.061
|
-0.117
|
-0.375
|
0.087
|
-0.082
|
-0.78**
|
Kulumsa
|
|
0.043
|
-0.167
|
-0.070
|
-0.034
|
0.003
|
-0.034
|
-0.062
|
-0.080
|
-0.374
|
0.087
|
-0.093
|
-0.78**
|
Holeta
|
PH
|
-0.020
|
0.098
|
0.090
|
0.039
|
-0.002
|
0.025
|
0.068
|
0.107
|
0.404
|
-0.089
|
0.083
|
0.80**
|
Kulumsa
|
|
-0.039
|
0.120
|
0.097
|
0.043
|
-0.002
|
0.031
|
0.069
|
0.074
|
0.403
|
-0.090
|
0.095
|
0.80**
|
Holeta
|
PB
|
-0.013
|
0.066
|
0.054
|
0.064
|
-0.004
|
0.023
|
0.065
|
0.099
|
0.410
|
-0.095
|
0.080
|
0.75**
|
Kulumsa
|
|
-0.026
|
0.081
|
0.059
|
0.071
|
-0.004
|
0.029
|
0.066
|
0.069
|
0.407
|
-0.096
|
0.090
|
0.75**
|
Holeta
|
SB
|
-0.004
|
0.017
|
0.011
|
0.015
|
-0.018
|
0.012
|
0.026
|
0.035
|
0.101
|
0.031
|
0.029
|
0.25**
|
Kulumsa
|
|
-0.008
|
0.021
|
0.012
|
0.016
|
-0.020
|
0.015
|
0.026
|
0.026
|
0.104
|
0.028
|
0.036
|
0.26**
|
Holeta
|
NC
|
-0.015
|
0.084
|
0.051
|
0.034
|
-0.005
|
0.043
|
0.060
|
0.105
|
0.340
|
-0.061
|
0.074
|
0.71**
|
Kulumsa
|
|
-0.028
|
0.103
|
0.055
|
0.037
|
-0.005
|
0.056
|
0.061
|
0.070
|
0.339
|
-0.062
|
0.084
|
0.71**
|
Holeta
|
NSC
|
-0.016
|
0.085
|
0.063
|
0.043
|
-0.005
|
0.027
|
0.097
|
0.116
|
0.515
|
-0.134
|
0.097
|
0.89**
|
Kulumsa
|
|
-0.031
|
0.104
|
0.068
|
0.048
|
-0.005
|
0.035
|
0.099
|
0.082
|
0.514
|
-0.135
|
0.110
|
0.89**
|
Holeta
|
TSW
|
-0.017
|
0.104
|
0.063
|
0.041
|
-0.004
|
0.030
|
0.074
|
0.154
|
0.426
|
-0.089
|
0.093
|
0.87**
|
Kulumsa
|
|
-0.032
|
0.121
|
0.064
|
0.045
|
-0.005
|
0.035
|
0.073
|
0.111
|
0.414
|
-0.088
|
0.103
|
0.84**
|
Holeta
|
BYP
|
-0.016
|
0.081
|
0.058
|
0.042
|
-0.003
|
0.024
|
0.080
|
0.104
|
0.629
|
-0.228
|
0.093
|
0.86**
|
Kulumsa
|
|
-0.032
|
0.100
|
0.063
|
0.046
|
-0.003
|
0.030
|
0.081
|
0.073
|
0.627
|
-0.230
|
0.106
|
0.86**
|
Holeta
|
HI
|
0.009
|
-0.042
|
-0.028
|
0.021
|
-0.002
|
-0.009
|
-0.046
|
-0.048
|
-0.504
|
0.285
|
-0.049
|
-0.46**
|
Kulumsa
|
|
0.017
|
-0.051
|
-0.031
|
-0.024
|
-0.002
|
-0.012
|
-0.047
|
-0.034
|
-0.503
|
0.286
|
-0.057
|
-0.46**
|
Holeta
|
OYP
|
-0.018
|
0.095
|
0.063
|
0.044
|
-0.004
|
0.027
|
0.080
|
0.122
|
0.496
|
-0.119
|
0.118
|
0.90**
|
Kulumsa
|
|
-0.035
|
0.117
|
0.069
|
0.048
|
-0.005
|
0.035
|
0.082
|
0.086
|
0.499
|
-0.122
|
0.133
|
0.91**
|
Holeta Residual=0.027767 Kulumsa Residual=0.02908
**: significant at p < 0.01 probability levels. DF= days to 50% flowering, DM= days to maturity, PH (cm)= plant height, PB= number of primary branches, SB= number of secondary branches, NC= number of capsules per plant, NSC= number of seeds per capsule, TSW (g)= thousand seed weight, BYP (kg)= biological yield per plant, HI (%)= harvest index, OYP (%)= oil yield per plant and SYP (g)= seed yield per plant.
It was observed that thousand seed weight and oil yield per plant exhibited positive and relatively low direct effect on seed yield per plant at Holeta and Kulumsa (Table 4). Traits such as oil yield per plant and thousand seed weight exerted positive indirect effects on seed yield per plant via biological yield per plant in both environments (Table 4). Harvest index showed relatively higher negative indirect effect to seed yield per plant through biological yield per plant. Similar results were reported by Patial [23] where harvest index showed relatively higher negative indirect effect to seed yield per plant through biological yield per plant was observed.
Plant height, number of primary braches per plant, number of capsules per plant and number of seeds per capsule had negligible direct positive effect and positive, highly significant correlation at phenotypic level with seed yield per plant. Number of secondary branches per plant had negative direct effect but positive highly significant phenotypic correlation with seed yield per plant at both locations. These indicate that the indirect effects seem to be the reason of correlation. In such situations, the indirect causal factors must be considered simultaneously.
Days to 50% flowering and harvest index had positive direct effect but negative highly significant phenotypic correlation at both locations. Under these circumstances, a restricted selection model is to be followed, that is restrictions are to be imposed to nullify the undesirables indirect effects, in order to make use of the direct effects. Days to maturity had negative direct effect and negative highly significant correlation at phenotypic level at both locations, indicating selection of early maturity is effective for improving seed yield per plant.
The residual effects of the present study were 0.027767 and 0.02908 at Holeta and Kulumsa, respectively which means the characters in the path analysis expressed the variability in seed yield per plant by 97.2233% and 97.092%, respectively.
3.3 The Genotypic Path Coefficient Analysis of Seed Yield per Plant at Holeta and Kulumsa
The path coefficient analysis at genotypic level at Holeta and Kulumsa (Table 5) showed that biological yield per plant (0.5836 and 0.5841) had the highest positive direct effect on seed yield per plant. Similarly, biological yield per plant had highly significant and positive correlations (rp= 0.90**, rp= 0.91**) with seed yield per plant in each location (Holeta and Kulumsa) at genotypic level. This indicates a direct selection through biological yield per plant will be effective in order to improve seed yield per plant of linseed. These results are in agreement with the findings of Tariq [34]; Paul [25] for biological yield per plant and partially agree with the finding of Tadesse [33] for harvest index and biomass yield.
Table 5. Direct (bold and underlined) and indirect effects (off diagonal) of traits on seed yield per plant at genotypic level at two location in2019/20
Location
|
Trait
|
DF
|
DM
|
PH
|
PB
|
SB
|
NC
|
NSC
|
TSW
|
BYP
|
HI
|
OYP
|
SYP rg
|
Holeta
|
DF
|
0.054
|
-0.111
|
-0.109
|
-0.054
|
0.002
|
-0.012
|
-0.063
|
-0.146
|
-0.412
|
0.096
|
-0.053
|
-0.81**
|
Kulumsa
|
|
0.094
|
-0.143
|
-0.128
|
-0.057
|
0.002
|
-0.025
|
-0.056
|
-0.108
|
-0.412
|
0.094
|
-0.066
|
-0.80**
|
Holeta
|
DM
|
0.049
|
-0.123
|
-0.101
|
-0.048
|
0.002
|
-0.012
|
-0.061
|
-0.157
|
-0.382
|
0.089
|
-0.052
|
-0.80**
|
Kulumsa
|
|
0.085
|
-0.159
|
-0.119
|
-0.051
|
0.002
|
-0.026
|
-0.054
|
-0.115
|
-0.382
|
0.087
|
-0.063
|
-0.80**
|
Holeta
|
PH
|
-0.047
|
0.099
|
0.126
|
0.064
|
-0.002
|
0.012
|
0.075
|
0.162
|
0.441
|
-0.095
|
0.058
|
0.89**
|
Kulumsa
|
|
-0.081
|
0.128
|
0.148
|
0.068
|
-0.002
|
0.027
|
0.067
|
0.119
|
0.442
|
-0.092
|
0.071
|
0.90**
|
Holeta
|
PB
|
-0.033
|
0.066
|
0.092
|
0.088
|
-0.004
|
0.011
|
0.072
|
0.140
|
0.435
|
-0.102
|
0.055
|
0.82**
|
Kulumsa
|
|
-0.057
|
0.086
|
0.108
|
0.094
|
-0.004
|
0.024
|
0.063
|
0.103
|
0.433
|
-0.099
|
0.066
|
0.84**
|
Holeta
|
SB
|
-0.008
|
0.016
|
0.019
|
0.023
|
-0.015
|
0.005
|
0.027
|
0.047
|
0.112
|
0.025
|
0.020
|
0.27**
|
Kulumsa
|
|
-0.015
|
0.021
|
0.023
|
0.024
|
-0.014
|
0.011
|
0.024
|
0.037
|
0.114
|
0.023
|
0.026
|
0.28**
|
Holeta
|
NC
|
-0.036
|
0.083
|
0.089
|
0.055
|
-0.004
|
0.018
|
0.062
|
0.150
|
0.354
|
-0.067
|
0.048
|
0.75**
|
Kulumsa
|
|
-0.062
|
0.107
|
0.104
|
0.058
|
-0.004
|
0.038
|
0.055
|
0.106
|
0.355
|
-0.065
|
0.059
|
0.76**
|
Holeta
|
NSC
|
-0.037
|
0.081
|
0.102
|
0.068
|
-0.004
|
0.012
|
0.093
|
0.163
|
0.522
|
-0.132
|
0.063
|
0.93**
|
Kulumsa
|
|
-0.065
|
0.104
|
0.121
|
0.073
|
-0.004
|
0.026
|
0.082
|
0.123
|
0.522
|
-0.128
|
0.077
|
0.92**
|
Holeta
|
TSW
|
-0.040
|
0.098
|
0.104
|
0.063
|
-0.004
|
0.014
|
0.076
|
0.197
|
0.455
|
-0.105
|
0.061
|
0.92**
|
Kulumsa
|
|
-0.068
|
0.123
|
0.118
|
0.065
|
-0.004
|
0.027
|
0.067
|
0.149
|
0.449
|
-0.099
|
0.074
|
0.90**
|
Holeta
|
BYP
|
-0.038
|
0.080
|
0.095
|
0.066
|
-0.003
|
0.011
|
0.083
|
0.153
|
0.584
|
-0.188
|
0.061
|
0.90**
|
Kulumsa
|
|
-0.066
|
0.104
|
0.112
|
0.070
|
-0.003
|
0.023
|
0.073
|
0.114
|
0.584
|
-0.182
|
0.074
|
0.91**
|
Holeta
|
HI
|
0.023
|
-0.048
|
-0.052
|
-0.039
|
-0.002
|
-0.005
|
-0.053
|
-0.090
|
-0.475
|
0.230
|
-0.037
|
-0.55**
|
Kulumsa
|
|
0.040
|
-0.062
|
-0.061
|
-0.042
|
-0.002
|
-0.011
|
-0.047
|
-0.066
|
-0.476
|
0.224
|
-0.045
|
-0.58**
|
Holeta
|
OYP
|
-0.040
|
0.087
|
0.099
|
0.066
|
-0.004
|
0.012
|
0.080
|
0.164
|
0.484
|
-0.117
|
0.073
|
0.91**
|
Kulumsa
|
|
-0.070
|
0.113
|
0.119
|
0.069
|
-0.004
|
0.025
|
0.071
|
0.123
|
0.487
|
-0.113
|
0.089
|
0.92**
|
Holeta Residual=0.018241 Kulumsa Residual=0.018739
**: significant at p < 0.01 probability levels. DF= days to 50% flowering, DM= days to maturity, PH (cm)= plant height, PB= number of primary branches, SB= number of secondary branches, NC= number of capsules per plant, NSC= number of seeds per capsule, TSW (g)= thousand seed weight, BYP (kg)= biological yield per plant, HI (%)= harvest index, OYP (%)= oil yield per plant and SYP (g)= seed yield per plant.
Thousand seed weight and plant height exhibited positive direct effect on seed yield per plant at Holeta and Kulumsa (Table 5). Plant height and thousand seed weight exerted positive indirect effects on seed yield per plant via biological yield per plant in both environments (Table 4). Harvest index showed relatively higher negative indirect effect to seed yield per plant through biological yield per plant. Similar results were reported by Patial [23] where harvest index showed relatively higher negative indirect effect to seed yield per plant through biological yield per plant was observed.
Plant height, number of primary braches per plant, number of capsules per plant and number of seeds per capsule had positive negligible direct effect and positive highly significant correlation at genotypic level with seed yield per plant. Number of secondary branches per plant had negligible negative direct effect but positive highly significant genotypic correlation with seed yield per plant at both locations. These indicate that the indirect effects seem to be the reason of correlation. In such situations, the indirect causal factors must be considered simultaneously.
Days to 50% flowering and harvest index had positive direct effect but negative highly significant genotypic correlation at both locations. This indicates to impose restrictions to nullify the undesirables’ indirect effects, in order to make use of the direct effects.
Days to maturity had negative direct effect and negative highly significant correlation at genotypic level at both locations, indicating selection of early maturity is effective for improving seed yield per plant.
The residual effects of the present study were 0.018241 and 0.018739 at Holeta and Kulumsa, respectively which means the characters in the path analysis expressed the variability in seed yield per plant by 98.1759% and 98.1261%, respectively.
3.4 The Phenotypic Path Coefficient Analysis of Oil Yield per Plant at Holeta and Kulumsa
Oil yield per plant was the dependent variable while other evaluated traits were considered as independent variables. Direct and indirect effects of these components were determined on oil yield per plant and their contributions in each of the two environments are shown in Table 6. The path coefficient analysis at phenotypic level revealed at Holeta and Kulumsa, respectively that seed yield per plant (0.897 and 0.889) had the highest positive direct effect on oil yield per plant. Similarly, oil yield per plant had highly significant and positive correlations (rp= 0.90**, rp= 0.91**) with seed yield per plant in each location (Holeta and Kulumsa), respectively at phenotypic level, indicating the need for direct selection for this trait in order to improve oil yield per plant of linseed. These results are in agreement with the findings of Wakjira [37]; Tadesse [33]; Mulusew [19]; Tariq [34]; Paul [25] for biological yield per plant.
Table 6. Direct (bold and underlined) and indirect effects (off diagonal) of traits on oil yield per plant at phenotypic level at two location in 2019/20
Location
|
|
DF
|
DM
|
PH
|
PB
|
SB
|
NC
|
NSC
|
TSW
|
BYp
|
HI
|
CRB
|
PRT
|
LN
|
LNN
|
SYP
|
OYP rp
|
Holeta
|
DF
|
0.035
|
-0.035
|
0.024
|
-0.004
|
-0.001
|
0.016
|
-0.009
|
0.004
|
0.001
|
-0.003
|
-0.024
|
|
-0.003
|
-0.003
|
-0.691
|
-0.69**
|
Kulumsa
|
DF
|
0.033
|
-0.009
|
-0.009
|
0.002
|
-0.003
|
0.011
|
0.004
|
-0.002
|
0.002
|
-0.008
|
-0.042
|
0.001
|
-0.002
|
0.000
|
-0.683
|
-0.70**
|
Holeta
|
DM
|
0.030
|
-0.040
|
0.022
|
-0.004
|
-0.001
|
0.017
|
-0.009
|
0.004
|
0.001
|
-0.003
|
-0.011
|
|
-0.002
|
-0.003
|
-0.702
|
-0.70**
|
Kulumsa
|
DM
|
0.029
|
-0.010
|
-0.008
|
0.002
|
-0.002
|
0.012
|
0.004
|
-0.002
|
0.002
|
-0.007
|
-0.012
|
-0.007
|
-0.001
|
0.000
|
-0.695
|
-0.70**
|
Holeta
|
PH
|
-0.027
|
0.029
|
-0.030
|
0.005
|
0.001
|
-0.016
|
0.010
|
-0.004
|
-0.001
|
0.003
|
0.012
|
|
0.003
|
0.001
|
0.718
|
0.70**
|
Kulumsa
|
PH
|
-0.026
|
0.007
|
0.012
|
-0.003
|
0.002
|
-0.011
|
-0.005
|
0.002
|
-0.002
|
0.007
|
0.012
|
0.002
|
0.002
|
0.000
|
0.712
|
0.71**
|
Holeta
|
PB
|
-0.018
|
0.019
|
-0.018
|
0.008
|
0.001
|
-0.015
|
0.010
|
-0.004
|
-0.001
|
0.003
|
0.020
|
|
0.007
|
0.000
|
0.671
|
0.68**
|
Kulumsa
|
PB
|
-0.017
|
0.005
|
0.007
|
-0.005
|
0.004
|
-0.010
|
-0.005
|
0.002
|
-0.002
|
0.008
|
0.016
|
0.003
|
0.003
|
0.000
|
0.664
|
0.67**
|
Holeta
|
SB
|
-0.005
|
0.005
|
-0.004
|
0.002
|
0.005
|
-0.007
|
0.004
|
-0.001
|
0.000
|
-0.001
|
0.017
|
|
0.001
|
0.003
|
0.228
|
0.25**
|
Kulumsa
|
SB
|
-0.005
|
0.001
|
0.001
|
-0.001
|
0.017
|
-0.005
|
-0.002
|
0.001
|
0.000
|
-0.002
|
0.043
|
-0.004
|
0.001
|
0.000
|
0.228
|
0.27**
|
Holeta
|
NC
|
-0.020
|
0.025
|
-0.017
|
0.004
|
0.001
|
-0.028
|
0.009
|
-0.004
|
-0.001
|
0.002
|
0.017
|
|
0.001
|
0.001
|
0.637
|
0.63**
|
Kulumsa
|
NC
|
-0.019
|
0.006
|
0.007
|
-0.002
|
0.005
|
-0.019
|
-0.004
|
0.002
|
-0.001
|
0.005
|
0.020
|
-0.002
|
0.001
|
0.000
|
0.631
|
0.63**
|
Holeta
|
NSC
|
-0.022
|
0.025
|
-0.021
|
0.005
|
0.001
|
-0.017
|
0.015
|
-0.004
|
-0.001
|
0.004
|
0.034
|
|
0.005
|
0.002
|
0.797
|
0.82**
|
Kulumsa
|
NSC
|
-0.021
|
0.006
|
0.008
|
-0.003
|
0.004
|
-0.012
|
-0.007
|
0.002
|
-0.002
|
0.011
|
0.044
|
0.003
|
0.003
|
0.000
|
0.790
|
0.83**
|
Holeta
|
TSW
|
-0.023
|
0.031
|
-0.021
|
0.005
|
0.001
|
-0.019
|
0.011
|
-0.006
|
-0.001
|
0.003
|
0.021
|
|
0.003
|
0.004
|
0.783
|
0.79**
|
Kulumsa
|
TSW
|
-0.021
|
0.007
|
0.008
|
-0.003
|
0.004
|
-0.012
|
-0.005
|
0.003
|
-0.002
|
0.007
|
0.033
|
0.001
|
0.002
|
0.000
|
0.748
|
0.77**
|
Holeta
|
BYp
|
-0.022
|
0.024
|
-0.020
|
0.005
|
0.001
|
-0.015
|
0.012
|
-0.004
|
-0.001
|
0.007
|
0.021
|
|
0.005
|
0.002
|
0.774
|
0.79**
|
Kulumsa
|
BYp
|
-0.021
|
0.006
|
0.008
|
-0.003
|
0.003
|
-0.010
|
-0.006
|
0.002
|
-0.003
|
0.018
|
0.029
|
0.004
|
0.003
|
0.000
|
0.766
|
0.80**
|
Holeta
|
HI
|
0.012
|
-0.012
|
0.010
|
-0.003
|
0.001
|
0.006
|
-0.007
|
0.002
|
0.001
|
-0.009
|
-0.005
|
|
-0.003
|
0.000
|
-0.409
|
-0.42**
|
Kulumsa
|
HI
|
0.011
|
-0.003
|
-0.004
|
0.002
|
0.002
|
0.004
|
0.003
|
-0.001
|
0.002
|
-0.023
|
-0.007
|
-0.003
|
-0.002
|
0.000
|
-0.407
|
-0.43**
|
Holeta Residual=0.011324 Kulumsa Residual=0.006013
Holeta Residual=0.011324 Kulumsa Residual=0.006013
ns and **, nonsignificant and significant at p < 0.01 probability levels, respectively. DF= days to 50% flowering, DM= days to maturity, PH (cm)= plant height, PB= number of primary branches, SB= number of secondary branches, NC= number of capsules per plant, NSC= number of seeds per capsule, TSW (g)= thousand seed weight, BYP (kg)= biological yield per plant, HI (%)= harvest index, CRB(%)=Carbohydrate, PRT(%)=Protein, OA(%)=Oleic acid, LN(%)= Linoleic acid, LNN(%)= Linolenic aid and SYP (g)= seed yield per plant.
Table 6.Continued.
Location
|
|
DF
|
DM
|
PH
|
PB
|
SB
|
NC
|
NSC
|
TSW
|
BYp
|
HI
|
CRB
|
PRT
|
LN
|
LNN
|
SYP
|
OYP rp
|
Holeta
|
CRB
|
0.002
|
-0.001
|
0.001
|
0.000
|
0.000
|
0.001
|
-0.001
|
0.000
|
0.000
|
0.000
|
-0.357
|
|
-0.027
|
-0.026
|
-0.052
|
-0.46**
|
Kulumsa
|
CRB
|
0.003
|
0.000
|
0.000
|
0.000
|
-0.002
|
0.001
|
0.001
|
0.000
|
0.000
|
0.000
|
-0.466
|
0.077
|
-0.013
|
-0.003
|
-0.053
|
-0.46**
|
Holeta
|
PRT
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
0.13ns
|
Kulumsa
|
PRT
|
0.000
|
-0.001
|
0.000
|
0.000
|
0.001
|
0.000
|
0.000
|
0.000
|
0.000
|
-0.001
|
0.317
|
-0.112
|
0.006
|
0.001
|
-0.029
|
0.18*
|
Holeta
|
LN
|
0.003
|
-0.002
|
0.002
|
-0.001
|
0.000
|
0.001
|
-0.002
|
0.000
|
0.000
|
-0.001
|
-0.211
|
|
-0.046
|
-0.010
|
-0.096
|
-0.36**
|
Kulumsa
|
LN
|
0.003
|
-0.001
|
-0.001
|
0.001
|
-0.001
|
0.001
|
0.001
|
0.000
|
0.000
|
-0.002
|
-0.274
|
0.031
|
-0.023
|
-0.001
|
-0.109
|
-0.37**
|
Holeta
|
LNN
|
-0.002
|
0.003
|
-0.001
|
0.000
|
0.000
|
-0.001
|
0.001
|
-0.001
|
0.000
|
0.000
|
0.248
|
|
0.013
|
0.038
|
0.052
|
0.35**
|
Kulumsa
|
LNN
|
-0.001
|
0.000
|
0.000
|
0.000
|
0.002
|
0.000
|
0.000
|
0.000
|
0.000
|
0.000
|
0.308
|
-0.036
|
0.007
|
0.004
|
0.013
|
0.30**
|
Holeta
|
Syp
|
-0.027
|
0.031
|
-0.024
|
0.006
|
0.001
|
-0.020
|
0.013
|
-0.005
|
-0.001
|
0.004
|
0.021
|
|
0.005
|
0.002
|
0.897
|
0.90**
|
Kulumsa
|
Syp
|
-0.025
|
0.008
|
0.009
|
-0.003
|
0.004
|
-0.014
|
-0.006
|
0.002
|
-0.002
|
0.010
|
0.028
|
0.004
|
0.003
|
0.000
|
0.889
|
0.91**
|
Holeta Residual=0.011324 Kulumsa Residual=0.006013
Holeta Residual=0.011324 Kulumsa Residual=0.006013
ns and **, nonsignificant and significant at p < 0.01 probability levels, respectively. DF= days to 50% flowering, DM= days to maturity, PH (cm)= plant height, PB= number of primary branches, SB= number of secondary branches, NC= number of capsules per plant, NSC= number of seeds per capsule, TSW (g)= thousand seed weight, BYP (kg)= biological yield per plant, HI (%)= harvest index, CRB(%)=Carbohydrate, PRT(%)=Protein, OA(%)=Oleic acid, LN(%)= Linoleic acid, LNN(%)= Linolenic aid and SYP (g)= seed yield per plant.
It was observed that number of secondary branches per plant and linolenic fatty acid exhibited negligible positive direct effect on oil yield per plant and highly significant phenotypic correlation at both locations. Plant height, number of primary branches per plant, number of seeds per capsule and thousand seed weight had positive highly significant correlation at phenotypic level with oil yield per plant but the direct effect was negative and negligible, the indirect effects seem to be the cause of correlation.
Days to 50% flowering had negative highly significant correlation with oil yield per plant but positive negligible direct effect. This indicates to impose restrictions to nullify the undesirables’ indirect effects, in order to make use of the direct effects.
Days to maturity, harvest index, number of capsules per plant, biological yield per plant, carbohydrate content and linoleic fatty acid had negative highly significant correlation with oil yield per plant and negative direct effect on oil yield per plant. This indicates selection of reduced linoleic fatty acid content is important to improve oil yield per plant.
At Kulumsa crude protein content had positive significant correlation at phenotypic level with oil yield per plant but the direct effect was negative and negligible, then the indirect effects seem to be the cause of correlation.
The residual effects of the present study were 0.011324 and 0.006013 at Holeta and Kulumsa, respectively which means the characters in the path analysis expressed the variability in oil yield per plant by 99.8676% and 99.3987%, respectively.
3.4 The Genotypic Path Coefficient Analysis of Oil Yield Per Plant at Holeta and Kulumsa
The path coefficient analysis at genotypic level at Holeta and Kulumsa (Table 7), revealed that seed yield per plant (0.975 and 0.884) had the highest positive direct effect on oil yield per plant. Similarly, seed yield per plant had highly significant and positive correlations (rg= 0.91**, rg= 0.92**) with oil yield per plant in each location (Holeta and Kulumsa), at genotypic level. The genotypic correlation between seed yield per plant and oil yield per plant is almost equal to its direct effect, this shows genotypic correlation explains the true relationship and direct selection through seed yield per plant will be effective to improve oil yield per plant of linseed. These results are in agreement with the findings of Wakjira [37]; Tadesse [33]; Mulusew [19]; Tariq [34]; Paul [25]for seed yield per plant.
Table 7
Direct (bold and underlined) and indirect effects (off diagonal) of traits on oil yield per plant at genotypic level at two location in 2019/20
Location
|
|
DF
|
DM
|
PH
|
PB
|
SB
|
NC
|
NSC
|
TSW
|
BYP
|
HI
|
CRB
|
PRT
|
LN
|
LNN
|
SYP
|
OYP rg
|
Holeta
|
DF
|
0.053
|
-0.026
|
-0.009
|
0.001
|
-0.004
|
0.010
|
0.017
|
0.040
|
0.038
|
-0.023
|
-0.033
|
|
-0.002
|
-0.002
|
-0.787
|
-0.73**
|
Kulumsa
|
|
0.046
|
-0.029
|
-0.002
|
-0.003
|
-0.003
|
0.018
|
0.005
|
-0.005
|
0.002
|
-0.011
|
-0.043
|
0.000
|
-0.003
|
0.000
|
-0.711
|
-0.74**
|
Holeta
|
DM
|
0.048
|
-0.029
|
-0.008
|
0.001
|
-0.004
|
0.010
|
0.016
|
0.043
|
0.035
|
-0.022
|
-0.014
|
|
-0.001
|
-0.002
|
-0.775
|
-0.71**
|
Kulumsa
|
|
0.042
|
-0.033
|
-0.002
|
-0.003
|
-0.003
|
0.019
|
0.004
|
-0.005
|
0.002
|
-0.010
|
-0.007
|
-0.009
|
-0.001
|
0.000
|
-0.703
|
-0.71**
|
Holeta
|
PH
|
-0.046
|
0.023
|
0.010
|
-0.001
|
0.004
|
-0.011
|
-0.020
|
-0.044
|
-0.040
|
0.023
|
0.017
|
|
0.002
|
0.001
|
0.872
|
0.79**
|
Kulumsa
|
|
-0.040
|
0.026
|
0.002
|
0.004
|
0.003
|
-0.020
|
-0.005
|
0.005
|
-0.002
|
0.011
|
0.022
|
0.000
|
0.002
|
0.000
|
0.791
|
0.80**
|
Holeta
|
PB
|
-0.033
|
0.016
|
0.007
|
-0.002
|
0.008
|
-0.010
|
-0.019
|
-0.038
|
-0.040
|
0.025
|
0.028
|
|
0.003
|
0.000
|
0.799
|
0.75**
|
Kulumsa
|
|
-0.028
|
0.018
|
0.002
|
0.005
|
0.005
|
-0.017
|
-0.005
|
0.005
|
-0.002
|
0.011
|
0.011
|
0.006
|
0.004
|
0.000
|
0.723
|
0.74**
|
Holeta
|
SB
|
-0.008
|
0.004
|
0.002
|
-0.001
|
0.029
|
-0.005
|
-0.007
|
-0.013
|
-0.010
|
-0.006
|
0.024
|
|
0.001
|
0.003
|
0.263
|
0.27**
|
Kulumsa
|
|
-0.007
|
0.004
|
0.000
|
0.001
|
0.020
|
-0.008
|
-0.002
|
0.002
|
0.000
|
-0.003
|
0.046
|
-0.005
|
0.001
|
0.000
|
0.242
|
0.29**
|
Holeta
|
NC
|
-0.035
|
0.019
|
0.007
|
-0.001
|
0.009
|
-0.015
|
-0.017
|
-0.041
|
-0.032
|
0.016
|
0.019
|
|
0.001
|
0.000
|
0.732
|
0.66**
|
Kulumsa
|
|
-0.030
|
0.022
|
0.002
|
0.003
|
0.006
|
-0.028
|
-0.004
|
0.005
|
-0.001
|
0.008
|
0.017
|
-0.002
|
0.001
|
0.000
|
0.664
|
0.66**
|
Holeta
|
NSC
|
-0.037
|
0.019
|
0.008
|
-0.002
|
0.008
|
-0.010
|
-0.025
|
-0.044
|
-0.048
|
0.032
|
0.042
|
|
0.003
|
0.002
|
0.906
|
0.86**
|
Kulumsa
|
|
-0.032
|
0.021
|
0.002
|
0.004
|
0.006
|
-0.019
|
-0.007
|
0.005
|
-0.002
|
0.015
|
0.041
|
0.004
|
0.003
|
0.000
|
0.822
|
0.86**
|
Holeta
|
TSW
|
-0.040
|
0.023
|
0.008
|
-0.001
|
0.007
|
-0.012
|
-0.021
|
-0.053
|
-0.041
|
0.026
|
0.030
|
|
0.001
|
0.003
|
0.896
|
0.83**
|
Kulumsa
|
|
-0.033
|
0.025
|
0.002
|
0.004
|
0.005
|
-0.020
|
-0.005
|
0.007
|
-0.002
|
0.011
|
0.032
|
0.004
|
0.002
|
0.000
|
0.796
|
0.83**
|
Holeta
|
BYp
|
-0.038
|
0.019
|
0.008
|
-0.001
|
0.005
|
-0.009
|
-0.022
|
-0.042
|
-0.053
|
0.045
|
0.029
|
|
0.003
|
0.001
|
0.881
|
0.83**
|
Kulumsa
|
|
-0.033
|
0.021
|
0.002
|
0.004
|
0.004
|
-0.017
|
-0.006
|
0.005
|
-0.002
|
0.021
|
0.028
|
0.004
|
0.003
|
0.000
|
0.798
|
0.83**
|
Holeta
|
HI
|
0.022
|
-0.011
|
-0.004
|
0.001
|
0.003
|
0.004
|
0.014
|
0.024
|
0.043
|
-0.056
|
-0.013
|
|
-0.002
|
0.000
|
-0.533
|
-0.51**
|
Kulumsa
|
|
0.019
|
-0.013
|
-0.001
|
-0.002
|
0.002
|
0.008
|
0.004
|
-0.003
|
0.002
|
-0.026
|
-0.008
|
-0.003
|
-0.002
|
0.000
|
-0.485
|
-0.51**
|
Holeta Residual = 0.0042 Kulumsa Residual = 0.005 |
ns and **, nonsignificant and significant at p < 0.01 probability levels, respectively. DF = days to 50% flowering, DM = days to maturity, PH (cm) = plant height, PB = number of primary branches, SB = number of secondary branches, NC = number of capsules per plant, NSC = number of seeds per capsule, TSW (g) = thousand seed weight, BYP (kg) = biological yield per plant, HI (%) = harvest index, CRB(%) = Carbohydrate, PRT(%) = Protein, OA(%) = Oleic acid, LN(%) = Linoleic acid, LNN(%) = Linolenic aid and SYP (g) = seed yield per plant. |
Table 7
Location
|
|
DF
|
DM
|
PH
|
PB
|
SB
|
NC
|
NSC
|
TSW
|
BYp
|
HI
|
CRB
|
PRT
|
LN
|
LNN
|
Syp
|
OYP rg
|
Holeta
|
CRB
|
0.004
|
-0.001
|
0.000
|
0.000
|
-0.002
|
0.001
|
0.002
|
0.004
|
0.003
|
-0.002
|
-0.448
|
|
-0.014
|
-0.020
|
-0.059
|
-0.46**
|
Kulumsa
|
|
0.004
|
-0.001
|
0.000
|
0.000
|
-0.002
|
0.001
|
0.001
|
0.000
|
0.000
|
0.000
|
-0.461
|
0.073
|
-0.015
|
-0.002
|
-0.048
|
-0.45**
|
Holeta
|
PRT
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
0.16ns
|
Kulumsa
|
|
0.000
|
-0.003
|
0.000
|
0.000
|
0.001
|
-0.001
|
0.000
|
0.000
|
0.000
|
-0.001
|
0.321
|
-0.105
|
0.007
|
0.001
|
-0.045
|
0.18*
|
Holeta
|
LN
|
0.004
|
-0.001
|
-0.001
|
0.000
|
-0.001
|
0.001
|
0.003
|
0.003
|
0.006
|
-0.004
|
-0.279
|
|
-0.023
|
-0.009
|
-0.104
|
-0.38**
|
Kulumsa
|
|
0.005
|
-0.001
|
0.000
|
-0.001
|
-0.001
|
0.001
|
0.001
|
-0.001
|
0.000
|
-0.003
|
-0.283
|
0.028
|
-0.024
|
-0.001
|
-0.107
|
-0.39**
|
Holeta
|
LNN
|
-0.004
|
0.003
|
0.000
|
0.000
|
0.003
|
0.000
|
-0.002
|
-0.007
|
-0.003
|
0.001
|
0.348
|
|
0.008
|
0.025
|
0.055
|
0.38**
|
Kulumsa
|
|
-0.002
|
0.001
|
0.000
|
0.000
|
0.003
|
0.001
|
0.000
|
0.001
|
0.000
|
0.000
|
0.341
|
-0.040
|
0.008
|
0.003
|
0.019
|
0.33**
|
Holeta
|
SYP
|
-0.043
|
0.023
|
0.009
|
-0.002
|
0.008
|
-0.012
|
-0.023
|
-0.049
|
-0.048
|
0.031
|
0.027
|
|
0.002
|
0.001
|
0.975
|
0.91**
|
Kulumsa
|
|
-0.037
|
0.026
|
0.002
|
0.004
|
0.005
|
-0.021
|
-0.006
|
0.006
|
-0.002
|
0.014
|
0.025
|
0.005
|
0.003
|
0.000
|
0.884
|
0.92**
|
Holeta Residual = 0.0042 Kulumsa Residual = 0.005 |
ns and **, nonsignificant and significant at p < 0.01 probability levels, respectively. DF = days to 50% flowering, DM = days to maturity, PH (cm) = plant height, PB = number of primary branches, SB = number of secondary branches, NC = number of capsules per plant, NSC = number of seeds per capsule, TSW (g) = thousand seed weight, BYP (kg) = biological yield per plant, HI (%) = harvest index, CRB(%) = Carbohydrate, PRT(%) = Protein, OA(%) = Oleic acid, LN(%) = Linoleic acid, LNN(%) = Linolenic aid and SYP (g) = seed yield per plant. |
Plant height, number of primary branches per plant, number of secondary branches per plant, number of capsules per plant, number of seeds per capsule, thousand seed weight and linolenic fatty acid had positive highly significant correlation at genotypic level with oil yield per plant but the direct effect was negative or negligible. At Kulumsa crude protein content had positive significant correlation at genotypic level with oil yield per plant but the direct effect was negative and negligible, this indicates that the indirect effects seem to be the reason of correlation.
Days to 50% flowering had negative highly significant correlation with oil yield per plant but positive negligible direct effect. This is mainly due to unfavorable indirect effect on oil yield per plant via days to 50% flowering.
Days to maturity, harvest index, carbohydrate content and linoleic fatty acid had negative highly significant correlation with oil yield per plant and negative direct effect on oil yield per plant. This indicates selections of reduced linoleic fatty acid containing genotypes are important to improve oil yield per plant.
The residual effects of the present study were 0.0042 and 0.005 at Holeta and Kulumsa, respectively which means the characters in the path analysis expressed the variability in oil yield per plant by 99.58% and 99.5%, respectively.