Research Article | | Peer-Reviewed

Genetic Variability and Heritability of Morpho-Agronomic Traits, Oil Yield and Fatty Acid Components in Linseed (Linumusitatissimum L.) Germplasm in Ethiopia

Received: 29 April 2024     Accepted: 17 May 2024     Published: 8 July 2024
Views:       Downloads:
Abstract

Comprehensive information on genetic variability and selection parameters is very crucial to design breeding strategies. However, very limited information is available in Ethiopian linseed germplasm. Therefore, the present study was conducted to estimate genetic variability, broad sense heritability and genetic advance; and determine selection for 19 quantitative traits using 126 genotypes (120 Ethiopian linseed accessions and six released varieties). The analysis of variance showed highly significant (P < 0.01) differences for all of the traits demonstrating the presence of high genetic diversity among the studied linseed genotypes. Higher differences between PCV and GCV estimates were observed for seed yield per plant and biological yield per plant, signifying the importance of environmental factors influence. High heritability coupled with high genetic advance was observed for seed yield per plant and biological yield per plant, indicating that this high heritability is due to additive gene effects and therefore, selection can be effective for the improvement of linseed for these traits. In addition, moderate heritability coupled with moderate genetic advance was recorded for oil yield per hectare, number of capsules, number of secondary branches, days to maturity, seed yield per hectare and plant height. These results indicated the existence of intermediate expression in these traits for both additive and dominance gene effect. In the present study, high heritability coupled with high GAM was observed for seed yield per plant and biological yield per plant, indicating greater contribution of additive gene action for the expression of these traits; and therefore, improvement can be achieved through selection in these traits.

Published in International Journal of Biomedical Science and Engineering (Volume 12, Issue 2)
DOI 10.11648/j.ijbse.20241202.11
Page(s) 19-33
Creative Commons

This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.

Copyright

Copyright © The Author(s), 2024. Published by Science Publishing Group

Keywords

Additive Effect, Coefficient of Variation, Genetic Advance

1. Introduction
Linum usitatissimum is one of the nearly 230 species of the family Linaceae which comprises about 14 genera. Linum usitatissimum is an annual herbaceous whose genus Linum includes nearly two thirds of the total species of the Linaceae family. Despite this remarkable diversity, linseed is the only cultivated species in that family . Flax is a self-pollinated species with a genome size approximately 370 Mb . There is a general consensus that the species may have originated in the regions east of the Mediterranean Sea towards India and spread throughout Asia and Europe. Linseed was first domesticated in the region known as the Fertile Crescent . Divergent selection applied over thousands of years has resulted in fiber and linseed types which are the same species but differ considerably in morphology, anatomy, physiology and agronomic performance . The linseed type, grown for oil extracted from the seed, is a relatively short plant which produces many secondary branches compared to the flax type, grown for the fiber extracted from the stem, which is taller and less branched .
Flax has been a source of food, feed, fiber, and medicine for more than 8,000 years . Linseed oil provides health benefits mainly due to its high content in omega-3 alpha linolenic acid (55-57%). Moreover, linseed oil has valuable attributes in paints and varnishes because of its unique drying properties that result from its distinctive fatty acid composition . The lignans contained in linseeds have been shown to have beneficial properties against breast, colon, prostate and thyroid cancer, and in lowering relative risk factors for heart disease .
Linseed produced on 48285.56 hectares of land by 544606 farmers and produced 44398.432 tons in Ethiopia during 2021/22 Meher season. Linseed is the fourth largest produced oil crop in which it accounted 24.65, 9.25 and 8.2% of farmers, cultivated land and total production of oil crops, respectively. The average national yield was 0.919t ha-1 . The low productivity in Ethiopia might be associated with the narrow genetic base and non-availability of high yielding varieties, cultivation in marginal lands and vulnerability to biotic and abiotic stresses .
Genetic variability plays the fundamental role in any plant breeding program. Quantifying genetic diversity present in crop species is of greatest importance as it provides the basis of selection for traits of interest . Additionally, reliable estimates of genetic and environmental variations are helpful in estimating the heritability and predicted genetic gain from selection . Overall, comprehensive knowledge on genetic variability, heritability and genetic advance allows geneticists and breeders to design breeding strategies for the improvement of crop productivity and quality .
Heritability and genetic advance are important selection parameters . Heritability estimates can be grouped as broad sense heritability or narrow sense heritability . Broad sense heritability provides information on the relative magnitude of genetic and environmental variation in specific population . Genetic advance is the measure of genetic gain under selection and depends on genetic variability, heritability and selection intensity. Genetic advance also indicates the mode of gene action in the expression of traits and helps in choosing breeding methods . Thus, heritability estimates coupled with genetic advance are more reliable and helpful in predicting the gain under selection than individual consideration of the parameters .
In linseed, genetic variability studies had been conducted by many researchers Debelo ; Mhiret and Heslop, ; Worku ; Mulusew ; Tadele ; Adugna and Labuschagne, using quantitative traits and proved the presence of high genetic variation among studied genotypes. Heritability and genetic advance had also been estimated for yield and related traits by several authors, Ashok ; Hussain ; Kumar ; Tadele ; Adugna and Labuschagne, . However, in Ethiopia large number of linseed genotypes (accessions) was collected by BID (Institute of Biodiversity) but, very limited research has been done in Ethiopian. Therefore, the present study was conducted to estimate genetic variability, heritability and genetic advance of morpho agronomic traits, oil yield and fatty acid components to determine selection in Ethiopian linseed accessions.
2. Materials and Methods
2.1. Experimental Sites
The study was conducted during 2019/20 in central Ethiopia in two locations, namely, Holeta (9°03′41”N, 38°30′44″ E) and Kulumsa (08°01′10”N, 39°09′11″ E). Holeta and Kulumsa are agricultural research stations of Ethiopian Institute of Agricultural Research (EIAR). These two sites represent agro-ecology of highland oil crops in Ethiopia. Holeta and Kulumsa are situated at an altitude of 2400 and 2200 m above sea level and receive a total rainfall of 976 and 820 mm, respectively. The mean minimum and maximum temperatures at Holeta site range from 6.1 to 22.4°C. Kulumsa has an average minimum and maximum temperature of 10.5 and 22.8°C. Holeta and Kulumsa has nitosol and luvisol soil types and soil PH 4.9 and 6, respectively .
Table 1. Weather conditions of Holeta and Kulumsa Research Centers during cropping season 2019/20.

Weather variable

Minimum temperature (°C)

Maximum temperature (°C)

Precipitation (mm)

Month

Holeta

Kulumsa

Holeta

Kulumsa

Holeta

Kulumsa

January

8

8.2

24

22.8

15.9

19

February

9

9.2

25

23.7

41.6

67

March

11

10.9

26

24.6

73.3

86

April

12

12

25

24.8

91.9

120

May

12

12.1

25

24.4

89.4

82

June

11

11.2

24

23.2

106.3

90

July

12

11.2

22

21.2

211

122

August

12

11

22

21

203.9

135

September

11

10.7

22

21.4

132.3

107

October

9

10.6

23

23

36.7

38

November

7

9

23

22.6

8

11

December

7

7.5

23

23

6

9

Mean

10.08

10.30

23.67

22.98

84.69

73.83

Source: Metrology Stations of Holeta and Kulumsa Agricultural Research Centers
Figure 1. Map of linseed accessions collected from Tigray (Yellow), Amhara (Blue), Oromia (Red) and SNNP (Light green) Admnistrative Regions of Ethiopia.
2.2. Descriptions of Experimental Materials
A total of 126 genotypes were evaluated of which the seeds of 120 accessions were obtained from Ethiopian Biodiversity Institute (EBI) collected from Tigray, Amhara, Oromia and SNNP administrative regions and different geographic regions and altitudes (1480 to 3440 m.a.s.l.) (Figure 1). The seeds of six improved varieties were obtained from Holeta and Kulumsa Agricultural Research Centers. Belay-96, Berene and Chilalo (Kulumsa-1) released in 1997, 2001 and 2006, respectively, while Jeldu, Kasa-2 and Bekoji released in 2010, 2012 and 2014, respectively . Seven altitude classes were made using the formulae: K = l + 3.32log10n and i = Range/K (Agarwal, ); Where i = class interval width, K = number of classes and n = sample size.
2.3. Experimental Design and Management
The experiment was conducted under field conditions and laid out using alpha lattice design , with two replications, at each location. In each replication there are 21 blocks and six plots in each block at each location. Each entry was planted in two rows plots of three meters in length, with an inter-row and intra-row spacing of 0.2 m and 0.1 m, respectively. The field management practices were practiced as the standard agronomic practices recommendation for linseed production by Holeta and Kulumsa Agricultural Research Centers .
2.4. Data Collected
Data for days to 50% flowering and days to maturity were recorded from all plants at each plot. The growth traits and yield components viz. plant height (cm), primary branches, secondary branches, number ofcapsules, number of seeds per capsule, 1000 seed weight (g), biological yield per plant (g), harvest index (%), seed yield per plant and seed yield (kg/ha) data were collected from ten randomly taken plants at each plot. Carbohydrate (%), crude protein (%), oleic acid (%), linoleic acid (%), linolenic acid (%), oil yield per plant and oil yield per hectare (kg/ha) were determined from samples taken from seeds collected for each genotype at each location.
2.5. Data Analysis
All the data were subjected to analysis using SAS software . The combined analysis of variance (ANOVA) over two locations (Holeta and Kulumsa) was carried out according to the model:
Pijk = µ + gi + bk(j)(s) + rj(s) + ls + (gl)is + eijks
Where: Pijks = phenotypic value of ith genotype under jthreplication at sth location and kth incomplete block within replication j and location s; µ = grand mean; gi = the effect of ith genotype; bk(j)(s) = the effect of incomplete block k within replication j and location s; rj(s) = the effect of replication j within location s; ls = the effect of location s; (gl)is = the interaction effects between genotype and location; and eijks = the residual or effect.
Estimation of Genetic Parameters
Phenotypic and genotypic variances and coefficients of variation
Estimates of variance components were computed using the formula suggested by Burton and De Vane as follows.
1. Genetic variance σg2=MSg-MSgllr at combined over two locations
2. Variance due to genotype by environment interaction= σgl2=MSgl-MSer
3. Intrablock error variance σe2=MSe
4. Phenotypic variance σp2=σg2+σgl2+σe2
Where, σ2gl = variance due to genotype by environment interaction, l = location,
σ2e = combined intra block error variance.
Estimation of phenotypic and genotypic coefficient of variations
Phenotypic coefficient variation, PCV=σp2x̅ ×100%
Genotypic coefficient of variation, GCV=σg2x̅×100%
x̅=Population mean of the character being evaluated
Heritability in broad sense
Heritability in the broad sense for quantitative traits will be computed using the formula suggested by Singh and Chaudhary :
H=σg2σp2×100%
Where,
H=Heritability in broad sense.
σg2=Genotypc variance
σp2=Phenotypic variance
Expected genetic advance: absolute genetic advance and as percent of mean at 5% selection intensity (k) will be calculated as suggested by Allard as follows:
GA=k*σp*H
Where,
GA=Expected genetic advance,
σp=Phenotypic standard deviation on mean basis,
H=Heritability in broad sense,
k=Selection differential (k=2.06 at 5% selection intensity)
Genetic advance as percent of mean (GAM) will be computed to compare the extent of predicted genetic advance of different traits under selection using the formula:
GAM=GAx̅*100%
Where,
GA=Expected genetic advance,
GAM=Genetic advance as percentage of mean
3. Results and Discussion
3.1. Coefficient of Variation (CV)
The coefficient of variation (CV) over the entire genotypes (Table 2) showed the least CV was from Linolenic acid (5.22%) whereas the highest CV from biological yield per plant (26.32%). Although the CV for precision varies greatly with the characters measured and type of plant, the above CV for linseed showed high precision in the measure of linolenic acid .
Accessions collected from SNNP and commercial varieties were with the least CVs (Table 3) for about 52.63% and 10.53% of morpho-agronomic traits, oil yield and fatty acid components, respectively. That is accessions from SNNP and commercial varieties were less variable.
Comparisons among altitudinal classes of accessions for CVs (Table 4) showed that accessions from altitude class I (1480-1700 m) were with the highest CV for number of secondary branches followed by biological yield per plant, but least CVs for linolenic acid oleic acid, days to 50% flowering, 1000-seed weight and linoleic acid. Accessions from altitude class II (1730-1970 m) showed the highest CVs for biological yield per plant followed by number of secondary branches, but with least CVs for oleic acid and linolenic acid. Accessions from altitude class III (1980-2210 m) were with the highest CV for biological yield per plant and number of secondary branches, but least CVs for linolenic acid and crude protien. Accessions from altitude class IV (2220-2460m) were with the highest CVs for biological yield per plant, number of secondary branches, number of capsules, oil yield per plant and oil yield per hectare, but least CVs for linolenic acid and crude protein.
Accessions from altitude class V (2480-2700 m) were with the highest CVs for biological yield per plant, number of capsules, number of secondary branches, and oil yield per plant, seed yield per plant, oil yield and seed yield per hectare. Accessions from altitude class VI (2710-2950 m) were with the highest CVs for number of capsules, biological yield per plant, days to maturity, oil yield per plant, seed yield per plant, oil yield and seed yield per hectare but with least CVs for oleic acid and linolenic acid. Accessions from altitude class VII (3040-3440 m) were with the highest CVs for biological yield per plant, number of capsules, oil yield per plant and oil yield per hectare but with least CVs for oleic acid and linolenic acid. This indicates that linseed accessions tend to be highly variable towards the higher altitude classes than the lowest altitude classes. This finding disagreed with the findings of Work who reported as linseed accessions tend to be highly variable towards the lowest altitude classes than to the highest altitude classes.
3.2. Mean Value
Accessions collected from Oromia showed the highest mean value (Table 3) for plant height, number of primary branches, number of secondary branches, and number of seeds per capsule, 1000-seed weight, biological yield per plant, oil yield per plant, seed yield per plant, oil and seed yield per hectare. Accessions collected from Tigray showed the highest mean values for days to maturity and harvest index. The highest mean values for number of capsules, crude protein, oleic acid, linoleic acid and linoleneic acid were from accessions collected from SNNP. In contrary, as Worku and Mulusew reported, low days to maturity and oleic acid showed from linseed accessions collected from Tigray, respectively. Accessions from Tigray showed the highest mean value for days to maturity but the least mean value for plant height. Oromia and SNNP were similar with the results reported by Mhret and Heslop for number of capsules and linolenic acid. The highest mean value for crude protein and oleic acid were from accessions collected from Tigray and SNNP . Commercial varieties revealed high mean values for days to 50% flowering and carbohydrate content.
Accessions collected from altitude class I (1480-1700 m) (Table 4) showed the least mean values for days to maturity, oleic acid and linolenic acid, but the highest mean values for plant height, number of primary branches, number of capsules, 1000-seed weight, harvest index, carbohydrate content and seed yield per plant. This indicates that linseed accessions from low altitudes adapt to mature early using the available short cycle of rain fall. This is in agreement with the reports of Worku and Mulusew on linseed accessions.
Accessions collected from altitude class II (1730-1970 m) were with the least mean value for days to 50% flowering and linoleic acid, but with highest mean value for biological yield, oil yield per plant and oil yield per hectare. Accessions collected from altitude class III (1980-2210 m) showed the least mean value for crude protein and maximum mean value for number of seeds per capsule. Accessions collected from altitude class IV (2220-2460 m) showed least mean value for plant height, number of primary branches, and number of seeds per capsule, 1000-seeds weight, biological yield, and oil yield per plant, seed yield per plant, oil yield and seed yield per hectare. Accessions collected from altitude class V (2480-2700 m) were with least mean values of number of capsules and harvest index. Accessions collected from altitude class VI (2710-2950 m) showed least mean value only for number of secondary branches.
Accessions collected from altitude class VII (3040-3440 m) were with the highest mean value for days to 50% flowering, days to maturity, number of secondary branches, crude protein, oleic acid, linolenic acid and seed yield per hectare, but with least mean value for carbohydrate content. This is in agreement with the finding by Worku that the number of secondary branches tends to be inversly correlated with 1000-seed weight, and the smallest seeds are found in areas with the high rainfall.
Mulusew and Worku reported that mean values are useful to determine variations within and between populations. Therefore, linseed accessions from Oromia and those from the high altitude class VII (3040-3440 m) are relatively high productive than the accessions from other regions and altitude classes, respectively. Accessions from lowest altitude class took 51and 50, and from highest altitude class, 61 and 63 days to flowering, and from flowering to maturity, respectively. This could be due to positive effect of longer growing season on growth. Maturing in the rainy season decreases the oil yield and seed yield per hectare and causes seed decay in linseed. This also agree with the report of Workuet . Therefore, adapting to longer flowering and maturity time in higher altitudes characterized with longer rainy season is advantageous for linseed to flower and mature towards the end of the rainy season.
Table 2. Mean, Std., Min., Max and CV forentire linseed genotypes (120 accessions and six commercial varieties).

Parameter

Character

DF

DM

PH

PB

SB

NC

NSC

TSW

BYP

HI

Mean

52.73

106.53

59.91

8.51

18.56

46.58

7.11

6.91

14.97

32.76

Std

5.6

18.09

8.54

1.13

4.46

9.85

0.89

0.79

3.94

4.02

Min

41

87.65

43.73

6.04

10.78

23.15

5.73

4.97

7.89

22.63

Max

66.26

151.2

76.51

11.2

25.87

69.68

9.48

8.15

28.67

44.92

CV%

10.63

16.98

14.26

13.31

24.02

21.14

12.53

11.49

26.32

12.28

Table 2. Continued.

Parameter

Character

CRB

PRT

OA

LN

LNN

OYP

SYP

OYD

SYD

Mean

26.27

19

22.07

9.26

50.52

190.69

4.68

953.47

2341.47

Std

3.56

1.38

1.6

1.33

2.64

36.7

0.78

183.5

391.06

Min

12.57

16.07

16.67

7.61

43.78

119.06

3.11

595.3

1555

Max

33.03

24.82

25.71

14.7

58.03

313.64

6.43

1568.2

3215

CV%

13.56

7.26

7.25

14.39

5.22

19.25

16.71

19.25

16.7

DH= Days to heading, DM= Days to maturity, PH (cm) = Plant height, PB= Primary branches, SB= Secondary branches, NC= Number ofcapsules, NSC= Number of seeds per capsule, TGW=1000-grain weight, BYP=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, SYP=Seed yield Perplant, OYD= Oil yield and SYD= Seedyield
Table 3. Mean, Std, CV and Range of morpho-aronomic traits, oil yield and fatty acid components by Administrative Regions.

Adm. Reg

Parameter

DF

DM

PH

PB

SB

NC

NSC

TSW

BYP

HI

TIGRAY

mean

53.29

111.5

57.21

8.04

18.77

41.91

6.78

6.53

13.82

33.6

(30 accessions)

Std

6.52

20.93

9.15

1.12

4.4

10.24

0.8

0.85

4.16

4.77

CV%

12.24

18.77

15.99

13.99

23.45

24.44

11.73

13.05

30.06

14.19

Range

25.26

63.55

32.78

5.06

14.83

36.95

3.65

2.86

20.78

22.29

AMHARA

MEAN

52.88

105.71

60.15

8.53

18.73

47.42

7.19

6.99

15.15

32.41

(46 accessions)

Std

5.37

17.08

8.31

1.08

4.46

9.21

0.9

0.72

3.69

3.71

CV%

10.15

16.16

13.82

12.67

23.79

19.41

12.46

10.35

24.34

11.45

Range

23.08

61.63

31.45

4.96

14.94

44.36

3.69

3.07

18.28

21.06

OROMIA

MEAN

50.75

101.68

63.07

9.09

19.02

50.25

7.41

7.22

16.29

32.62

(39 accessions)

Std

5.2

16.88

8.56

1.21

4.46

9.23

1

0.78

4.58

4.48

CV%

10.24

16.6

13.57

13.32

23.45

18.37

13.45

10.8

28.1

13.73

Range

20.89

54.97

28.71

3.94

13.71

39.9

3.15

2.69

17.56

19.35

SNNP

MEAN

53.54

101.56

61.42

8.48

15.29

51.06

7.16

7.11

14.33

33.25

(5 accessions)

Std

0.17

6.99

0.43

0.4

0.62

7.07

0.11

0.13

0.95

1.53

CV%

0.32

6.89

0.7

4.67

4.02

13.85

1.58

1.79

6.66

4.59

Range

0.24

9.89

0.61

0.56

0.87

10

0.16

0.18

1.35

2.16

COMM. VAR

MEAN

55.61

110.74

58.26

8.47

14.97

45.24

6.81

6.83

13.86

32.74

(6 varieties)

Std

4.51

18.61

6.27

0.69

4.61

11.55

0.52

0.89

1.83

1.31

CV%

8.12

16.8

10.77

8.17

30.78

25.54

7.62

13.03

13.18

3.99

Range

11.67

49.49

16.36

1.86

12.75

31.56

1.46

2.28

5.5

3.51

Table 3. Continued.

Adm. Reg

Parameter

CRB

PRT

OA

LN

LNN

OYP

SYP

OYD

SYD

TIGRAY

Mean

26.46

19.04

22.27

9.53

50.55

175.9

4.37

879.5

2186.33

(30 accessions)

Std

3.15

1.09

1.34

1.74

2.61

33.99

0.82

170

410.4

CV%

11.9

5.72

6.01

18.21

5.16

19.32

18.77

19.32

18.77

Range

15.86

4.91

4.78

7.07

11.8

132.58

3.32

662.9

1660

AMHARA

Mean

26.19

19.03

21.96

9.21

50.6

192.98

4.72

964.9

2358.85

(46 accessions)

Std

3.34

1.31

1.73

1.07

2.53

35.8

0.73

179

366.19

CV%

12.77

6.88

7.88

11.63

5.01

18.55

15.52

18.55

15.52

Range

17.61

6.92

9.04

5.48

11.66

194.58

3.22

972.9

1610

OROMIA

Mean

25.79

18.98

22.01

8.61

50.61

208.15

5.05

1041

2522.61

(39 accessions)

Std

3.55

1.25

1.51

0.74

2.87

37.32

0.81

186.6

407.23

CV%

13.77

6.57

6.86

8.62

5.66

17.93

16.14

17.93

16.14

Range

17.1

6.89

6.11

2.35

12.02

139.31

2.74

696.5

1370

SNNP

Mean

22.03

21.08

23.9

10.56

51.99

200.98

4.7

1005

2350

(5 accessions)

Std

13.37

5.29

0.56

4.16

6.75

48.8

0.1

244

49.5

CV%

60.71

25.09

2.34

39.46

12.99

24.28

2.12

24.28

2.11

Range

18.91

7.48

0.79

5.89

9.55

69.01

0.14

345

70

COMM. VAR

Mean

29.47

17.93

21.92

10.44

48.68

169.55

4.46

847.7

2231.67

(6 varieties)

Std

2.07

1.79

1.87

1.23

1.42

24.45

0.59

122.3

293.22

CV%

7.04

9.98

8.54

11.83

2.92

14.42

13.14

14.42

13.14

Range

4.47

4.96

4.68

3.68

4.41

68.6

1.62

343

810

For character codes see Table 2.
Table 4. Mean, Std, CV and Range of morpho-aronomictrais, oil yield and fatty acid components by altitude classes.

Altitude

Parameter

DF

DM

PH

PB

SB

NC

NSC

TSW

BYP

HI

class I

Mean

51.36

99.30

63.54

8.73

18.66

50.53

7.14

7.22

14.89

33.98

(1480-1700)

Std

2.64

7.11

5.70

0.73

5.62

7.28

0.48

0.39

2.79

3.61

(9 accessions)

CV%

5.13

7.16

8.98

8.30

30.13

14.40

6.71

5.43

18.71

10.62

Range

8.48

19.67

17.19

2.46

14.43

22.27

1.51

1.34

7.97

11.74

class II

Mean

50.80

101.98

61.71

8.67

17.40

45.76

7.16

7.04

15.64

32.39

(1730-1970)

Std

4.83

13.67

7.29

1.09

4.15

8.17

0.90

0.69

4.37

4.20

(25 accessions)

CV%

9.51

13.41

11.81

12.59

23.87

17.85

12.51

9.80

27.96

12.97

Range

20.89

55.43

28.71

3.73

14.97

30.33

3.37

2.51

19.15

21.38

class III

Mean

53.42

107.37

59.48

8.53

19.13

48.20

7.19

6.93

14.68

33.28

(1980-2210)

Std

5.32

18.72

8.46

1.10

4.28

8.36

0.86

0.75

3.55

3.63

(27 accessions)

CV%

9.95

17.43

14.22

12.87

22.38

17.35

11.93

10.83

24.18

10.92

Range

19.26

55.65

28.19

3.54

14.83

27.52

3.03

2.53

11.72

13.07

class IV

Mean

53.82

109.10

57.19

8.04

19.58

46.07

7.03

6.78

14.67

32.38

(2220-2460)

Std

5.84

19.95

7.83

1.06

4.96

10.49

1.04

0.88

4.00

3.98

(19 accessions)

CV%

10.85

18.29

13.69

13.24

25.35

22.76

14.75

13.02

27.27

12.29

Range

18.33

56.40

26.95

4.56

14.63

37.56

3.25

2.99

13.46

13.84

class V

Mean

52.84

108.67

58.77

8.65

19.18

44.55

7.14

6.79

15.29

32.06

(2480-2700)

Std

6.74

21.44

10.11

1.37

4.41

11.98

1.06

0.92

5.05

5.08

(23 accessions)

CV%

12.76

19.73

17.20

15.81

22.98

26.90

14.79

13.51

33.05

15.85

Range

24.36

63.55

32.48

4.61

14.62

43.27

3.75

2.86

20.78

22.29

class VI

Mean

53.22

108.85

61.05

8.50

16.77

45.93

7.10

6.85

14.76

32.70

(2710-2950)

Std

7.48

23.15

11.33

1.43

3.27

13.34

1.06

1.07

3.96

3.20

(9 accessions)

CV%

14.05

21.27

18.55

16.88

19.51

29.04

14.89

15.68

26.83

9.78

Range

21.70

61.62

31.31

4.66

11.28

42.77

2.87

3.06

13.25

11.55

class VII

Mean

61.74

124.82

61.42

8.44

20.70

47.98

7.05

6.95

14.76

33.83

(3040-3440)

Std

5.51

17.74

10.26

1.20

3.06

9.92

0.75

0.74

3.24

4.80

(8 accessions)

CV%

10.53

16.43

16.70

14.23

14.78

20.67

10.57

10.69

21.95

14.20

Range

14.46

50.72

25.05

2.85

10.05

28.82

1.84

2.08

7.58

14.97

Table 4. Continued.

Altitude

Parameter

CRB

PRT

OA

LN

LNN

OYP

SYP

OYD

SYD

class I

Mean

28.23

18.67

21.15

9.33

49.44

192.2

4.9

961.02

2385

(1480-1700)

Std

2.18

1.22

1.08

0.54

2.34

20.09

0.47

100.47

235.4

(9 accessions)

CV%

7.71

6.54

5.12

5.76

4.74

10.45

9.6

10.45

9.6

Range

6.49

3.98

2.68

1.3

7.89

63.61

1.38

318.08

690

class II

Mean

24.99

19.42

22.18

8.92

50.96

200.65

4.82

1003.27

2408.6

(1730-1970)

Std

4.85

1.63

1.32

1.27

3.03

39.62

0.77

198.13

383.59

(25 accessions)

CV%

19.42

8.38

5.93

14.23

5.94

19.75

15.93

19.75

15.93

Range

17.7

6.92

4.83

5.88

10.98

174

2.74

869.98

1370

class III

Mean

26.8

18.63

22.28

9.25

49.79

190.14

4.71

950.68

2355.37

(1980-2210)

Std

2.59

1.02

1.82

1.38

2.62

33.17

0.76

165.83

381.92

(27 accessions)

CV%

9.67

5.49

8.16

14.96

5.26

17.44

16.21

17.44

16.21

Range

7.8

4.91

6.42

5.95

10.42

109.45

2.44

547.21

1220

class IV

Mean

26.62

18.97

22.1

9.48

50.89

183.45

4.54

917.24

2269.21

(2220-2460)

Std

2.48

0.86

2.05

1.57

2.22

38.87

0.79

194.38

397.61

(19 accessions)

CV%

9.32

4.55

9.28

16.53

4.36

21.19

17.52

21.19

17.52

Range

9.41

3.88

9.04

7.04

8.54

132.61

2.69

663.09

1345

class V

Mean

25.44

19.12

21.81

9.1

51.09

190.22

4.58

951.12

2288.04

(2480-2700)

Std

3.76

1.49

1.69

1.61

2.51

41.71

0.93

208.55

464.37

(23 accessions)

CV%

14.77

7.8

7.73

17.71

4.92

21.93

20.29

21.93

20.3

Range

18.82

7.51

6.5

5.59

11.43

144.89

3.32

724.46

1660

class VI

Mean

26.86

19.02

22.25

9.18

50.36

186.36

4.65

931.83

2326.11

(2710-2950)

Std

2.22

1.43

0.77

0.7

2.55

38.98

0.97

194.92

485.93

(9 accessions)

CV%

8.26

7.54

3.48

7.63

5.06

20.92

20.89

20.92

20.89

Range

7.15

4.9

2.19

2.09

7.04

113.41

2.86

567.01

1430

class VII

Mean

24.8

19.88

22.65

9.37

51.87

199.04

4.77

995.22

2452.22

(3040-3440)

Std

4.51

1.61

1.15

0.86

3.02

40.17

0.74

200.85

369.86

(8 accessions)

CV%

18.18

8.07

5.09

9.13

5.83

20.18

15.51

20.18

15.51

Range

13.26

4.22

3.53

2.38

9.69

122.08

1.82

610.39

910

For character codes see Table 2.
3.3. Analysis of Variance (ANOVA)
The analysis of variance (ANOVA) computed for each location for 19 quantitative traits of linseed genotypes revealed the presence of highly significant differences among genotypes for all traits. Combined analysis of variance across locations (Holeta and Kulumsa) for the different characters is presented in Table 5. The location variance showed non-significant differences for all traits except days to 50% flowering, days to maturity, plant height, seed yield per plant and seed yield per hectare (kg ha-1). The interaction variance between genotypes x location was found non-significant for all the traits indicating consistence performance of the genotypes across locations. Mean square due to genotype showed highly significant differences (P<0.01) for all traits, indicating that presence of genotypic variation among the tested linseed genotypes. Mulusew and Worku also reported variations among on linseed landraces and commercial varieties for morpho-agronomic and biochemical traits evaluated at different locations in Ethiopia. Many other authors also reported significant variations among linseed genotypes for morpho-agronomic traits, oil yield and fatty acid composition in Ethiopia .
3.4. Estimates of Variances and Genetic Parameters
3.4.1. Estimates of Variances
Estimates of genotypic (2g), genotype by environment interaction (2g*l), pooled error (environmental) (2e) and phenotypic (2p) variances were estimated for the studied traits (Table 6). Phenotypic variance was relatively high for the traits like seed yield per hectare, days to maturity and number of capsules. This indicated that the phenotypic expression of these traits was greatly influenced by environmental factors; and selection on phenotypic bases of these traits may not be effective for genetic improvement unless the environmental conditions are optimized. Similarly, in another studies, relatively higher phenotypic variance for days to 50% flowering, days to maturity, number of primary branches, seed yield per plot, oleic acid, linoleic acid, linolenic acid and crude protein content were reported by Mulusew . On the contrary, degree of difference between phenotypic variance and genotypic variance was relatively low for number of seeds per capsule, 1000-seed weight and number of primary branches. This shows that the phenotypic expression of these traits was relatively less affected by environmental factors; and selection on phenotypic bases of these traits will be effective. Gemechu and Gudeta also indicated lower degree of difference between phenotypic and genotypic variances for days to 50% flowering and biomass. However, the same authors reported relatively high and low degree of differences between phenotypic and genotypic variances for days to maturity and harvest index, respectively. This variation of phenotypic expression of the two traits between studies might be mainly due to differences in environmental conditions of the two research sites.
3.4.2. Coefficients of Variation
Genetic (GCV) and phenotypic (PCV) coefficients of variability values for 19 traits varied from 1.32% to 3.52% for oil yield per plant and 28.02%to 34.98% for seedl yield per plant, respectively (Table 6). Estimates of GCV and PCV had been reported for the same traits of linseed by previous investigators (Gemechu and Gudeta, ; Debelo ; Tadele ; Adugna ). It has been reported that GCV and PCV values, > 20%, 10-20% and < 10% are regarded as high, moderate and low, respectively .
High GCV value was obtained for traits seed yield per plant and biological yield per plant (Table 6). This indicated the existence of considerable genotypic variability among linseed genotypes for these traits and greater influence of genetic factors for the expression of this trait. High GCV estimate for seed yield per plant and biological yield per plant was reported by several authors, Ashok ; Singh ; Tadele . Moderate GCV value was obtained for traits like number of secondary branches, number of capsules, seed yield per hectare and days to maturity (Table 6). In line with the present results, moderate GCV was reported by Kumar for number of secondary branches; by Singh et al. (2019) for seed yield per plant; and by Tadele for seed yield per hectare and days to maturity.
Low GCV value was obtained for traits like linoleic acid, plant height, carbohydrate content, number of primary branches, number of seeds per capsule, harvest index, days to 50% flowering, 1000-seed weight, oil yield per hectare, oleic acid, crude protein, lenolenic acid and oil yield per plant (Table 6). Similarly, low GCV estimates were reported by Gemechu and Gudeta for days to 50% flowering, days to maturity and number of seeds per capsule; and Debelo for plant height, days to maturity, days to flowering and oil content. However, on the contrary, low GCV estimate was reported by Singh for number of secondary branches; and by Debelo for days to maturity. These differences might be due to differences between sets of accessions used for the studies or environmental conditions of research sites where genotypes were grown for characterization.
High PCV was revealed for seed yield per plant (34.98%), biological yield per plant (33.27%), number of secondary branches (23.37%) and number of capsules (20.87%) (Table 6). These results reflected the presence of considerable phenotypic variation among linseed genotypes for these traits. The high PCV estimates for seed yield per plant, biological yield per plant, number of secondary branches and number of capsules were in harmony with the previous reports by several authors .
In the present study, moderate PCV values were exhibited for traits like seed yield per hectare, days to maturity, linoleic acid, carbohydrate content, plant height, numberof primary branches, harvest index, number of seeds per capsule, 1000-seed weight and days to 50% flowering. On the hand, low PCV was observed for oil yield per hectare, crude protein content, oleic acid, linolenic acid and oil yield per plant, indicating existence of lesser phenotypic variability among linseed genotypes that might be due to higher influence of environmental factors for the expression of the traits. In agreement with the present result, low PCV estimate for oil yield per plant and moderate PCV for harvest index was reported by Fekadu . However, in contrast to the present study, low PCV estimate was reported by Rajanna for traits like days to 50% flowering, plant height and number of seeds per capsule; and by Singh for plant height. These differences might be due to differences in genetic bases of the studied materials for these traits or higher influence of environmental factors for their expression.
Higher differences between PCV and GCV estimates were observed for number of secondary branches, number of capsules and biological yield per plant, (Table 6) indicating the complexity of these traits and the importance of environmental factors in influencing the expression of these traits. High differences between PCV and GCV were also reported inlinseed by previous authors (Gemechu and Gudeta, ; Debelo ) for biological yield per plant, number of secondary branches and number of capsules. Similar results were reported by Fekadu for number of capsules and biologicalyield per plant. However, difference between PCV and GCV estimates was relatively very slight in the case of linolenic acid and oil yield per plant, signifying minimal influence of environment and a reasonable effect of genotypic factors on the expression of these traits.
Table 5. Mean squares from combined analysis of variance for 19 morpho-agronomic traits and seed biochemical contents of 126 linseed genotypes evaluated at Holeta and Kulumsa during 2019/20 main cropping season.

LOC

REP

REP (LOC)

BLOC (REP)

GEN

GEN*LOC

ERROR

CV%

S.V

(d.f=1)

(d.f=1)

(d.f=1)

(d.f=40)

(d.f=125)

(d.f=125)

(d.f=210)

Days to 50% flowering

2.14**

38.12ns

25.52ns

9.05ns

68.84**

20.47ns

15.26

7.41

Days to maturity

2.41**

38.11ns

25.51ns

131.54ns

718.36**

187.77ns

161.94

11.95

Plant height (cm)

2.47**

38.12ns

25.52ns

32.03ns

153.93**

55.59ns

36.27

10.05

Number of primary branches

0.31ns

38.11ns

25.51ns

0.71ns

2.58**

0.93ns

0.74

10.08

Number of secondary branches

0.15ns

38.12ns

25.52ns

8.57ns

40.44**

15.49ns

9.66

16.75

Number ofcapsules per plant

0.24ns

38.11ns

25.51ns

35.62ns

209.72**

68.17ns

49.98

15.18

Number of seeds per capsule

0.51ns

38.11ns

25.52ns

0.52ns

1.64**

0.58ns

0.42

9.12

1000 seeds weight (g)

0.11ns

38.12ns

25.52ns

0.85ns

1.34**

0.54ns

0.34

8.42

Biological yield per plant (g)

0.73ns

38.11ns

25.51ns

8.34ns

72.05**

11.78ns

7.71

18.55

Harvest index (%)

0.83ns

38.12ns

25.52ns

8.54ns

38.4**

16.77ns

7.5

8.36

Carbohydrate (%)

0.58ns

38.11ns

25.51ns

3.36ns

31.62**

15.08ns

5.41

8.85

Crudeprotein (%)

0.25ns

38.11ns

25.52ns

0.93ns

4.24**

1.92ns

0.92

5.04

Oleic acid (%)

0.52ns

38.25ns

25.51ns

1.12ns

5.45**

1.93ns

1.39

5.35

Linoleic acid (%)

0.15ns

38.11ns

25.57ns

0.48ns

4.16**

1.77ns

0.83

9.84

Linolenic acid (%)

0.85ns

38.11ns

25.55ns

2.38ns

16.36**

3.88ns

2.98

3.41

Oil yield per plant (g plant-1)

0.42ns

37.85ns

23.75ns

8.32ns

65.35**

39.92ns

37.47

3.21

Seed yield per plant (g plant-1)

1.26**

36.83ns

22.57ns

7.01ns

8.05**

1.17ns

0.74

18.38

Oil yield (kg ha-1)

0.62ns

21629.41ns

14479.5ns

13793.53ns

74197.99**

18711.63ns

17681.47

13.95

Seed yield (kg ha-1)

2.21**

38.12ns

25.51ns

80171.48ns

321226.5**

85662.7ns

81946.74

12.23

ns and **, non-significant and significant at P<0.01, respectively. Loc = Location, Gen = Genotype, Gen*Loc = Genotype by location interaction and CV (%) = Percentage of coefficient of variation. Number in parenthesis indicates the degree of freedom.
Table 6. Estimates of coefficients of variation, heritability and genetic advance for 19 Morpho agronomic traits, oil yield and fatty acid components in 126 (120 accessions and 6 commercial varieties) linseed genotypes (2019/20).
In general, coefficients of genotypic and phenotypic variation suggest that there is good scope for improvement through selection for seed yield per plant and biological yield per plant. Similar results were reported for traits like number of capsules, seed yield per plant and biological yield per plant in linseed accessions .
3.4.3. Broad Sense Heritability
Heritability estimates for traits under study varied from 14.11% for oil yield per plant to 64.18% for seed yield per plant (Table 3). According to Johnson , these heritability estimates can be classified as low (< 30%), moderate (30-60%) and high (> 60%) levels. Hence, high heritability estimate was recorded for seed yield per plant and biological yield per plant. This result indicated that expression of these traits were least influenced by the environmental factors, signifying a close correspondence between genotype and phenotype due to a relatively smaller contribution of environment to phenotypic expression. However, selection may not be useful for these traits, because broad sense heritability is based on total genetic variance which includes both fixable (additive) and non-fixable (dominance and epistatic) variances . Similarly, Singh reported high heritability estimates for seed yield per plant and biological yield per plant.
Traits like harvest index, 1000-seed weight, linoleic acid, number of primary branches, number of secondary branches, oleic acid, plant height, number of seeds per capsule, number of capsules, days to 50% flowering, seed yield per hectare, days to maturity, oil yield per hectare and linolenic acid revealed moderate level of heritability. For such traits, phenotypic expression is influenced by environmental factors and the non-additive gene effects; and hence, genetic improvement through selection is difficult due to masking effects of the environment on the genotypic effects . Further, the lowest heritability estimate was recorded for oil yield per plant (14.11%), carbohydrate content (28.75%) and crude protein (29%); these indicated that a small proportion of the phenotypic variation is caused by variation in genotypes, signifying that the phenotypic expression of this trait was highly influenced by environmental factors with less contribution of genetic factors. In agreement with the present results, moderate level of heritability was reported by Gemechu and Gudeta for plant height and number of primary branches and Debelo reported moderate level of heritability for number of primary branches.
3.4.4. Genetic Advance
In present study, genetic advance as a percent mean (GAM) ranged from 1.02% oil yield per plant to 46.25% for seed yield per plant (Table 6). These results indicated that selecting the top 5% of the accessions could result in an advance of 1.02% to 46.25% over the respective population mean. As suggested by Johnson , estimates of genetic advance can be classified as low (< 10%), moderate (10-20%) and high (> 20%).
High GAM was recorded for seed yield per plant and biological yield per plant. These results indicated that the expressions of these traits are mainly governed by additive gene effects; and therefore, improvement of such trait can be achieved through selection. In harmony to the present findings, Gemechu and Gudeta reported high GAM for number of capsules per plant, seed yield per plant and biological yield per plant. Similarly, Rajanna reported high GAM for linoleic acid, linolenic acid, number of capsules and seed yield per plant.
On the contrary, oil yield per hectare, number of capsules, number of secondary branches, days to maturity, seed yield per hectare and plant height revealed moderate level of GAM. In addition, low genetic advance was recorded for traits like linoleic acid, number of seeds per capsule, number of primary branches, days to 50% flowering, carbohydrate content, harvest index, 1000-seed weight, oleic acid, linolenic acid, crude protein and oil yield per plant. This indicated that expression of these traits is governed by non-additive gene effects; and hence, heterosis breeding may be useful for the improvement of these traits than selection. Similarly, Gemechu and Gudeta reported low GAM for number of seeds per capsule in linseed accessions. However, in contrast to the present results, Gemechu and Gudeta reported moderate level of GAM for days to maturity, number of secondary branches and plant height. Additionally, Rajanna reported moderate level of GAM for days to maturity and 1000 seed weight. These differences might be due to difference in magnitude of the different gene effects or the influence of environmental factors.
3.4.5. Scope of Selection
In the present study, high heritability coupled with high GAM was observed for seed yield per plant and biological yield per plant (Table 6), indicating greater contribution of additive gene action for the expression of these traits; and therefore, improvement can be achieved through selection in these traits. Similarly, Gemechu and Gudeta reported high heritability coupled with high GAM for seed yield per plant and biological yield per plant. However, it is not necessary for a trait showing high heritability to exhibit high GAM or the vise-versa .
In addition, moderate heritability coupled with moderate genetic advance was recorded for oil yield per hectare, number of capsules, number of secondary branches, days to maturity, seed yield per hectare and plant height. These results indicated the existence of intermediate expression in these traits for both additive and dominance gene effect. Similar results were reported for days to maturity by Debelo ; Rajanna . Furthermore, moderate heritability coupled with low GAM was recorded for linoleic acid, number of seeds per capsule, number of primary branches, days to 50% flowering, harvest index, 1000-seed weight, oleic acid and linolenic acid, suggesting that the expression of these traits is governed by non-additive gene action. However, the exhibited moderate heritability might be mostly due to favorable influence of the environment rather than the genetic factors. Additionally, low heritability and low GAM were recorded for carbohydrate content, crude protein and oil yield per plant, indicating that the expression of these traits is governed by non-additive gene effects; and inf1uenced negatively by environmental effects. In general, these results indicate the predominance of non-additive gene action in the inheritance of carbohydrate content, crude protein and oil yield per plant, suggesting that selection may not be effective for the improvement of these traits, and rather heterosis breeding may be useful. Similar suggestion was given for the traits exhibiting non-additive gene action .
4. Conclusions
In conclusion, the analysis of variance showed the presence of high genetic diversity among the studied linseed genotypes. Traits like number of secondary branches and number of capsules were highly influenced by the environment factors compared to other traits. The role of additive gene action was high for seed yield per plant and biological yield per plant; and therefore, selection can do improvement on these traits. High heritability coupled with high GAM was observed for seed yield per plant and biological yield per plant showing that the high heritability is most likely due to additive gene effects; and the importance of selection for the improvement of linseed for these traits. On the contrary, the role of additive gene effects was low for carbohydrate content, crude protein and oil yield per plant indicating limited scope of selection for improvement for these traits; rather heterosis breeding may be useful.
Abbreviations

HARC

Holeta Agricultural Research Center

KARC

Kulumsa Agricultural Research Center

EIAR

Ethiopian Institute of Agricultural Research

EBI

Ethiopian Biodiversity Institute

SNNP

Southern Nations and Nationalities Administrative Region

Author Contributions
Tadesse Ghiday: Conceptualization, Data curation, Formal Analysis, Methodology, Writing – original draft, Writing – review & editing
Wasu Mohammed: Conceptualization, Data curation, Formal Analysis, Methodology, Resources, Software, Supervision, Writing – review & editing
Yemane Tsehaye: Conceptualization, Funding acquisition, Investigation, Methodology, Project administration, Resources, Software, Supervision, Validation, Visualization
Adugna Wakjira: Funding acquisition, Investigation, Project administration, Resources, Supervision, Validation
Chemeda Daba: Formal Analysis, Investigation, Methodology, Software, Validation, Writing – original draft, Writing – review & editing
Tesfaye Desasa: Formal Analysis, Methodology, Software, Validation, Visualization, Writing – original draft, Writing – review & editing
Conflicts of Interest
The authors declare no conflicts of interest.
References
[1] Diederichsen A, Kusters PM, Kessler D, Bainas Z, Gugel RK. Assembling a core collection from the flax world collection maintained by plant gene resources of Canada. Genet Resour Crop Evol. (2013) 60: 1479–85.
[2] Kaur, V., Singh, M., Wankhede, D. P., Gupta, K., Langyan, S., Aravind, J., Thangavel, B., Yadav. S. K., Kalia, S., Singh, K. and Kumar, A. 2023. Diversity of Linum genetic resources in global genebanks: from agro-morphological characterisation to novel genomic technologies: A review Front. Nutr. 10: 1165580.
[3] Mhiret WN, Heslop-Harrison JS. Biodiversity in Ethiopian linseed (Linum usitatissimum L.): molecular characterization of landraces and some wild species. Genet Resour Crop Evol. (2018) 65: 1603–14.
[4] Vavilov, N. I. (1951). The Origin, Variation, Immunity and Breeding of Cultivated Plants, Vol. 13. The Ronald Press Company, New York, pp. 20–43.
[5] Hoque A, Fiedler JD, Rahman M. Genetic diversity analysis of a flax (Linum usitatissimum L.) global collection. BMC Genomics. (2020) 21: 557.
[6] Adugna, W. and Labuschagne, M. T. 2004. Diversity analysis in Ethiopian and some exotic collections of linseed. S. Afr. J. Plant Soil 21: 53-58.
[7] Worku N, Heslop-Harrison JS, Adugna W. Diversity in 198 Ethiopian linseed (Linum usitatissimum) accessions based on morphological characterization and seed oil characteristics. Genet Resour Crop Evol. (2015) 62: 1037–53.
[8] Liu FH, Chen X, Long B, Shuai RY, Long CL. Historical and botanical evidence of distribution, cultivation and utilization of Linum usitatissimum L. (flax) in China. Veget Hist Archaeobot. (2011) 20: 561–6.
[9] Zare S, Mirlohi A, Saeidi G, Sabzalian MR, Ataii E. Water stress intensified the relation of seed color with lignan content and seed yield components in flax (Linum usitatissimum L.). Sci Rep. (2021) 11: 23958.
[10] DinsaYadetaDabalo, Chandra Sekhar Singh, B. and BulchaWeyessa. 2020. Genetic variability and association of characters in linseed (Linumusitatissimum L.) plant grown in central Ethiopia region. Saudi Journal of Biological Sciences, 27(8): 2192–2206.
[11] van Zeist W, Bakker-Heeres JAH. Evidence for linseed cultivation before 6,000 B.C. J Archaeol Sci. (1975) 2: 215–9.
[12] De Silva SF, Alcorn J. Flaxseed lignans as important dietary polyphenols for cancer prevention and treatment: chemistry, pharmacokinetics, and molecular targets. Pharmaceuticals. (2019) 12: 68.
[13] Adolphe JL, Whiting SJ, Juurlink BH, Thorpe LU, Alcorn J. Health effects with consumption of the flax lignan secoisolariciresinol diglucoside. Br J Nutr. (2020) 103: 929–38.
[14] ESS (Ethiopian Statistics Service). 2022. Agricultural Samples Survey 2021/22 (2014 E.C.) Volume I. Report on Area and Production of Major Crops (Private Peasant Holdings, Meher Season), statistical bulletin 59, Addis Ababa, April, 2022.
[15] Hussain ME, Goyal VK, Paul PJ, Yadav Y, Jha UC, Moitra PK. Assessment of genetic variability, diversity, and identification of promising lines in linseed germplasm for harnessing genetic gain in central plain of the Indian subcontinent. J Plant Breed Crop Sci. (2022) 14: 12–20.
[16] Kumar M, Patel M, Chauhan R, Tank C, Solanki S. Delineating multivariate divergence, heritability, trait association and identification of superior omega-3-fatty acid specific genotypes in linseed (Linum usitatissimum L.). Genetika. (2021) 53: 825–36.
[17] Tadele Tadesse, Parven A, Singh H, Bulcha Weyessa. Estimates of variability and heritability in linseed germplasm. Int J Sustain Crop Prod. (2010) 5: 8–16.
[18] Mulusew Fikere, Firew Mekbib, Adugna Wakjira. Seed oil diversity of Ethiopian linseed (Linum usitatissimum L.) landraces accessions and some exotic cultivars. Afr J Biochem Res. (2013) 7: 76–85.
[19] Mulusew Fikre Ali, Firew Mekbib, Adugna Wakjira. Morphological diversity of Ethiopian linseed (Linum usitatissimum L.) landrace accessions and non-native cultivars. J Plant Breed Genet. (2014) 2: 115–24.
[20] Johnson HW, Robinson HF, Comstock R. (1955). Estimates of Genetic and Environmental Variability in Soybeans. Agronomy J, 47(7): 314-318.
[21] Rajanna B, Gangaprasad S, Shanker Goud I, Dushyantha Kumar BM, Girijesh GK and Sathish KM. Genetic variability, heritability and genetic advance of yield components and oil quality parameters in linseed (Linum usitatissimum L.). International Journal of Chemical Studies 2020; 8(1): 1768-1771.
[22] Vipin Kumar Singh, SA Kerkhi, ShivendraPratap Singh and PrakritiTomar. Study on genetic variability, heritability and genetic advance for grain yield and yield component traits (Linumusitatissimum L.). Journal of Pharmacognosy and Phytochemistry (2019) 8: 761-765.
[23] You FM, Jia G, Xiao J, Duguid SD, Rashid KY, Booker HM, et al. Genetic variability of 27 traits in a core collection of flax (Linum usitatissimum L.). front. Plant Sci. (2017) 8: 1636.
[24] Saroha A, Pal D, Kaur V, Kumar S, Bartwal A, Aravind J, et al. Agro-morphological variability and genetic diversity in linseed (Linum usitatissimum L.) germplasm accessions with emphasis on flowering and maturity time. Genet Resour Crop Evol. (2022) 69: 315–33.
[25] Ashok Kumar Meena, Sandhya Kulhari and Manoj Kumar (2023). Genetic variability, heritability and correlation coefficient in linseed (Linum usitatissimum L.). The Pharma Innovation Journal 2023; 12(3): 3011-3015.
[26] HARC. Annual Research Report for the Period 2015/16; Holeta Agricultural Research Centre: Oromia, Ethiopia, 2016.
[27] KARC. Annual Research Report for the Period 2015/16; Kulumsa Agricultural Research Centre: Oromia, Ethiopia, 2016.
[28] EAA (Ethiopian Agriculture Authority). 2021. Plant Variety Release, Protection and Seed Quality Control Directorate, Crop Variety Register, Issue No. 24, June 2021, Addis Ababa, Ethiopia.
[29] Agarwal, B. L. (1996). Basic Statistics, 3rd ed. New Age International (P) Limited, New Delhi, 713 pp.
[30] Patterson and Williams; A new class of resolvable incomplete block design, Biometrika Vol, 63. No. 1 (April, 1976), pp 83-92.
[31] SAS Institute (2001). SAS software. SAS Institute INC., Cary. NC. USA.
[32] Burton GW, Devane EH. Estimating heritability in tall fescue (Festuca arundinaceia) from replicated clonal material. Agronomy Journal. 1953; 45: 478-481.
[33] Singh RK, Chaudhary BD (1985). Biometrical Methods in Quantitative Genetics Analysis. Kalyanin publishers, New Delhi-Ludhiana.
[34] Allard RW (1960). Principles of plant breeding. John Wiley and Sons.
[35] Gomez, K. A., Gomez, A. A., 1984. Statistical procedure for Agriculture Research. John Willey and Sons, Singapore.
[36] Gemechu Nedi Terfa and Gudeta Nepir Gurmu. Genetic variability, heritability and genetic advance in linseed (Linum usitatissimum L) genotypes for seed yield and other agronomic traits. Oil Crop Science. (2020) 156–160.
[37] Deshmukh, S. N., Basu, M. S. and Reddy, P. S. 1986. Genetic variability, character association and path coefficient analysis of quantitative traits in Virginia bunch varieties of groundnut. Indian Journal of Agricultural Sciences 56: 816-821.
[38] Fekadu Amsalu. 2020. Estimates of heritability, genetic and principal components analysis for yield and its traits in linseed genotypes (Linumusitatissimum L.) in central highlands of Ethiopia. International Journal of Research in Agriculture and Forestry, 7(9): 01-06.
[39] Singh, P. and Narayanan, S. S. 1997. Biometrical Techniques in Plant Breeding. Kalyani Publishers. New Delhi, India.
Cite This Article
  • APA Style

    Ghiday, T., Mohamed, W., Tsehaye, Y., Wakjira, A., Daba, C., et al. (2024). Genetic Variability and Heritability of Morpho-Agronomic Traits, Oil Yield and Fatty Acid Components in Linseed (Linumusitatissimum L.) Germplasm in Ethiopia. International Journal of Biomedical Science and Engineering, 12(2), 19-33. https://doi.org/10.11648/j.ijbse.20241202.11

    Copy | Download

    ACS Style

    Ghiday, T.; Mohamed, W.; Tsehaye, Y.; Wakjira, A.; Daba, C., et al. Genetic Variability and Heritability of Morpho-Agronomic Traits, Oil Yield and Fatty Acid Components in Linseed (Linumusitatissimum L.) Germplasm in Ethiopia. Int. J. Biomed. Sci. Eng. 2024, 12(2), 19-33. doi: 10.11648/j.ijbse.20241202.11

    Copy | Download

    AMA Style

    Ghiday T, Mohamed W, Tsehaye Y, Wakjira A, Daba C, et al. Genetic Variability and Heritability of Morpho-Agronomic Traits, Oil Yield and Fatty Acid Components in Linseed (Linumusitatissimum L.) Germplasm in Ethiopia. Int J Biomed Sci Eng. 2024;12(2):19-33. doi: 10.11648/j.ijbse.20241202.11

    Copy | Download

  • @article{10.11648/j.ijbse.20241202.11,
      author = {Tadesse Ghiday and Wassu Mohamed and Yemane Tsehaye and Adugna Wakjira and Chemeda Daba and Teasfaye Disasa},
      title = {Genetic Variability and Heritability of Morpho-Agronomic Traits, Oil Yield and Fatty Acid Components in Linseed (Linumusitatissimum L.) Germplasm in Ethiopia
    },
      journal = {International Journal of Biomedical Science and Engineering},
      volume = {12},
      number = {2},
      pages = {19-33},
      doi = {10.11648/j.ijbse.20241202.11},
      url = {https://doi.org/10.11648/j.ijbse.20241202.11},
      eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijbse.20241202.11},
      abstract = {Comprehensive information on genetic variability and selection parameters is very crucial to design breeding strategies. However, very limited information is available in Ethiopian linseed germplasm. Therefore, the present study was conducted to estimate genetic variability, broad sense heritability and genetic advance; and determine selection for 19 quantitative traits using 126 genotypes (120 Ethiopian linseed accessions and six released varieties). The analysis of variance showed highly significant (P < 0.01) differences for all of the traits demonstrating the presence of high genetic diversity among the studied linseed genotypes. Higher differences between PCV and GCV estimates were observed for seed yield per plant and biological yield per plant, signifying the importance of environmental factors influence. High heritability coupled with high genetic advance was observed for seed yield per plant and biological yield per plant, indicating that this high heritability is due to additive gene effects and therefore, selection can be effective for the improvement of linseed for these traits. In addition, moderate heritability coupled with moderate genetic advance was recorded for oil yield per hectare, number of capsules, number of secondary branches, days to maturity, seed yield per hectare and plant height. These results indicated the existence of intermediate expression in these traits for both additive and dominance gene effect. In the present study, high heritability coupled with high GAM was observed for seed yield per plant and biological yield per plant, indicating greater contribution of additive gene action for the expression of these traits; and therefore, improvement can be achieved through selection in these traits.
    },
     year = {2024}
    }
    

    Copy | Download

  • TY  - JOUR
    T1  - Genetic Variability and Heritability of Morpho-Agronomic Traits, Oil Yield and Fatty Acid Components in Linseed (Linumusitatissimum L.) Germplasm in Ethiopia
    
    AU  - Tadesse Ghiday
    AU  - Wassu Mohamed
    AU  - Yemane Tsehaye
    AU  - Adugna Wakjira
    AU  - Chemeda Daba
    AU  - Teasfaye Disasa
    Y1  - 2024/07/08
    PY  - 2024
    N1  - https://doi.org/10.11648/j.ijbse.20241202.11
    DO  - 10.11648/j.ijbse.20241202.11
    T2  - International Journal of Biomedical Science and Engineering
    JF  - International Journal of Biomedical Science and Engineering
    JO  - International Journal of Biomedical Science and Engineering
    SP  - 19
    EP  - 33
    PB  - Science Publishing Group
    SN  - 2376-7235
    UR  - https://doi.org/10.11648/j.ijbse.20241202.11
    AB  - Comprehensive information on genetic variability and selection parameters is very crucial to design breeding strategies. However, very limited information is available in Ethiopian linseed germplasm. Therefore, the present study was conducted to estimate genetic variability, broad sense heritability and genetic advance; and determine selection for 19 quantitative traits using 126 genotypes (120 Ethiopian linseed accessions and six released varieties). The analysis of variance showed highly significant (P < 0.01) differences for all of the traits demonstrating the presence of high genetic diversity among the studied linseed genotypes. Higher differences between PCV and GCV estimates were observed for seed yield per plant and biological yield per plant, signifying the importance of environmental factors influence. High heritability coupled with high genetic advance was observed for seed yield per plant and biological yield per plant, indicating that this high heritability is due to additive gene effects and therefore, selection can be effective for the improvement of linseed for these traits. In addition, moderate heritability coupled with moderate genetic advance was recorded for oil yield per hectare, number of capsules, number of secondary branches, days to maturity, seed yield per hectare and plant height. These results indicated the existence of intermediate expression in these traits for both additive and dominance gene effect. In the present study, high heritability coupled with high GAM was observed for seed yield per plant and biological yield per plant, indicating greater contribution of additive gene action for the expression of these traits; and therefore, improvement can be achieved through selection in these traits.
    
    VL  - 12
    IS  - 2
    ER  - 

    Copy | Download

Author Information
  • Ethiopian Institute of Agricultural Research, Holeta Agricultural Research Center, Holeta, Ethiopia

  • Haramaya University, Faculty of Environment and Plant Science, Haramaya University, Dire Dawa, Ethiopia

  • Mekele University, Faculty of Environment and Plant Science, Mekele University, Mekele, Ethiopia

  • Ethiopian Institute of Agricultural Research, Holeta Agricultural Research Center, Holeta, Ethiopia

  • Oromia Institute of Agricultural Research, Addis Ababa, Ethiopia

  • Ethiopian Institute of Agricultural Research, Holeta Agricultural Research Center, Holeta, Ethiopia

  • Abstract
  • Keywords
  • Document Sections

    1. 1. Introduction
    2. 2. Materials and Methods
    3. 3. Results and Discussion
    4. 4. Conclusions
    Show Full Outline
  • Abbreviations
  • Author Contributions
  • Conflicts of Interest
  • References
  • Cite This Article
  • Author Information