SSR Inst. Int. J. Life Sci., 6(6): 2694-2703, November 2020

 

Studies on Heterosis and Heterobeltiosis in Selected Quantitative Traits during Summer Season in Bivoltine Silkworm, Bombyx mori L.

 

Mir Nisar Ahmad1*, Bharath Kumar Neelaboina2, Shivkumar2, Kiran R3, Sukhen Roy Chowdhury4

 

1Scientist D, Silkworm Division, Central Sericultural Research and Training Institute, Central Silk Board, Pampore (J&K), India

2Scientist C, Silkworm Division, Central Sericultural Research and Training Institute, Central Silk Board, Pampore (J&K), India

3Scientist B, Silkworm Division, Central Sericultural Research and Training Institute, Central Silk Board, Pampore (J&K), India

4Director, Central Sericultural Research and Training Institute (CSR&TI), Central Silk Board, Pampore, Jammu & Kashmir, India

 

*Address for Correspondence: Dr. Mir Nisar Ahmad, Scientist-D, Silkworm Division, Central Sericultural Research and Training Institute (CSR&TI), Central Silk Board, Gallandar, Pampore-192121, Jammu & Kashmir, India

E-mail: mirnisarahmad@gmail.com

 

ABSTRACT- Background: The phenomenon of heterosis has been commercially exploited in agriculture, horticulture, animal husbandry, piggery, poultry and sericulture. Heterosis is the phenotypic result of gene interaction in heterozygotes and the degree of heterosis increases as the genetic similarities between two parent’s decreases.

Methods: The present study was carried out at Central Sericultural Research and Training Institute (CSR&TI), Central Silk Board, Gallandar, Pampore during summer 2019 (July-August) and extent of heterosis was studied in six quantitative traits viz., Cocoon yield per 10000 larvae by weight, Single cocoon weight, Single shell weight, Shell ratio, Filament length and Pupation rate in a set of 30 bivoltine silkworm hybrids along with three control hybrids. The data generated were analysed statistically and subjected to multiple trait Evaluation index (E.I).

 Results: The average relative heterosis values ranged from-5.59 (DUN6 X DUN22) to 4.94 (S8 X CSR27). Among the 30 hybrids studied only 13 hybrids showed a variable amount of relative heterosis. The average heterobeltiosis values ranged from -6.90 (Pam117 X DUN 22) to 3.08 (S8 X CSR27). Among the 30 hybrids, only 8 hybrids showed a variable amount of heterobeltiosis. Maximum relative heterosis and heterobeltiosis have been observed in filament length (17.14 & 14.73, respectively).

Conclusion: Hybrids having CSR 27, Pam 117, S8 and N5 as one of the parents have shown higher heterosis and heterobeltiosis. Among the hybrids S 8 X CSR27 and CSR27 X Pam117 have shown higher relative heterosis and heterobeltiosis. The results have also been confirmed through evaluation index values calculated on relative heterosis and heterobeltiosis.

Key Words: Cervical Cancer, Women, Perception Barriers, Effectiveness


INTRODUCTION- The silkworm, B. mori L (Lepidoptera: Bombycidae) is an insect of great importance for its production of silk, aptly named the queen of natural fibres [1]. This unique lepidopteran insect completes its life cycle while engineering an economically distinct structure made of silk called cocoon [2]. The lepidopteran species have been reared for silk production for more than 5000 years [3]. Since then, silkworms have undergone many evolutionary changes due to natural as well as manmade selections after several thousands of generations, thereby creating a wide genetic diversity [4].

Since so many years sericulture has proved to have considerable socio-economic relevance in India due to its suitability to small and marginal farmers and also due to low-cost investment. The major commercial silkworm rearing is being practised under temperate climatic conditions of Kashmir division of the Union Territory of Jammu & Kashmir during the spring season (May-June) only and about 15-20% rearers conduct second rearing during the autumn season (August-September). It has been observed that many rearers due to one reason or the other are unable to conduct rearing during the spring season and are interested in conducting rearing during summer season [5] (July-August) on the left overleaf of the spring season. It is to mention here that from a single set of the mulberry plantation, under recommended pruning schedule for Kashmir climatic conditions, the leaf is available for two rearings in a year i.e., spring and autumn. As summer season can also be exploited for a limited commercial rearing on left overleaf of spring flush or from a separate set of mulberry plantation pruned for harvesting leaf during the summer season[6], need was felt to identify silkworm hybrids suitable for rearing during the summer season. The Kashmir weather averages during summer months are depicted in Table 1.

 

Table 1: Kashmir Weather Averages for June, July and August 2019

Months

Min. Temp. (0C)

 

Max.  Temp. (0C)

 

Average Temp. (0C)

 

Average Precipitation/ Rainfall (mm)

Avg. Sunlight hours/Day

Relative Humidity (%)

June

14.0

29.0

21.5

36

7.5

57

July

18.0

31.0

24.5

61

8.0

62

August

18.0

30.0

24.0

62

7.5

67

 

MATERIALS AND METHOD

The present study was carried out at Central Sericultural Research and Training Institute (CSR&TI), Central Silk Board, Gallandar, Pampore during summer, 2019 (July-August). Six silkworm parental races viz., CSR27, Pam 117, S8, N5, DUN22 and DUN6 were selected based on their better performance during the summer season. The six races were crossed (Full diallel) resulting in 30 hybrid combinations. The extent of heterosis was studied in six quantitative traits viz., Cocoon yield per 10000 larvae by weight, Single cocoon weight, Single shell weight, Shell ratio, Filament length and Pupation rate in these 30 bivoltine silkworms (B. mori L.) hybrids along with three control hybrids viz., SH6 X NB4D2, CSR6 X CSR26 and CSR2 X CSR27. The standard rearing techniques were followed [7]. The parental races were reared in three replications each and the hybrids were reared in two replications per hybrid. 250 larvae were retained in each replication after 3rd moult.

The data generated for each trait was pooled and analysed to evaluate the performance of the parents as well as the degree of manifestation of heterosis and heterobeltiosis in the hybrids. The heterosis and heterobeltiosis in the F1 crosses were calculated by using the following formula:

 

Heterosis = F1–MPV / MPV × 100

           

Heterobeltiosis = F1–BPV/ BPV × 100

 

Where, F1= Mean of the hybrid, MPV= Mid parent value, BPV= Better parent value

Evaluation index values were calculated on the values of heterosis and heterobeltiosis obtained for all the traits. The evaluation index (EI) was ca1cuated as per the below-mentioned procedure [8].

 

Evaluation Index =   A – B / C × 10 + 50

Where,

A= Value obtained for a trait in a breed

B = Mean value of a trait of all the breed

C= Standard deviation of a trait of all the breeds

10 = Standard unit

50= Fixed value

The index value obtained for all the traits was combined and the average EI values were obtained. The EI value fixed for the selection of a line is 50 or >50. The genotype, which scored above the limit, is considered to possess greater economic value.

 

RESULTS- The average rearing and reeling performance of the parental races and the F1 crosses are presented in Table 2 and 3.

 

Table 2: Average rearing and reeling performance of the parental races during summer, 2019

S.No.

Race

Cocoon Yield/10000 larvae by wt. (kg)

Single Cocoon Weight(g)

Single Shell Weight(g)

Shell Ratio

(%)

Filament Length

(m)

Pupation rate

(%)

1

CSR 27

13.17

1.63

0.33

20.21

768

88.00

2

Pam 117

13.87

1.67

0.34

20.14

855

92.00

3

S 8

13.24

1.55

0.32

20.32

860

89.00

4

N 5

13.80

1.64

0.33

20.07

859

85.00

5

DUN 22

14.90

1.62

0.32

19.81

801

86.00

6

DUN 6

14.18

1.69

0.33

19.22

776

89.00

7

CSR 2

13.70

1.65

0.34

20.30

835

85.00

8

CSR 6

12.52

1.63

0.32

19.81

784

84.00

9

CSR 26

13.84

1.63

0.33

19.99

862

87.00

10

SH 6

14.20

1.70

0.31

17.96

744

92.00

11

NB4D2

13.80

1.56

0.29

18.26

776

92.00

MEAN

13.75

1.63

0.32

19.64

810.91

88.09

SD

0.62

0.05

0.01

0.82

44.09

2.98

 

Table 3: Average rearing and reeling performance of hybrids during summer, 2019

S.No

Hybrid

Cocoon Yield/10000 larvae by wt.(kg)

Single Cocoon Weight

(g)

Single Shell Weight

(g)

Shell Ratio

(%)

Filament Length (m)

Pupation rate

(%)

1

CSR 27 X Pam 117

15.38

1.63

0.34

20.57

869

92.00

2

CSR 27 X S 8

13.84

1.57

0.30

19.06

813

85.00

3

CSR 27 X N 5

14.74

1.60

0.29

18.17

844

92.00

4

Pam 117 X CSR 27

14.44

1.60

0.34

20.97

859

95.00

5

Pam 117 X S 8

13.84

1.65

0.32

19.43

809

86.00

6

Pam 117 X N 5

14.50

1.67

0.35

20.92

904

91.00

7

S 8 X CSR 27

14.18

1.59

0.33

20.71

914

94.00

8

S 8 X Pam 117

14.60

1.69

0.35

20.66

839

90.00

9

S 8 X N 5

13.78

1.56

0.30

18.87

842

91.00

10

N 5 X CSR 27

13.08

1.55

0.29

18.41

851

92.00

11

N 5 X Pam 117

13.30

1.50

0.32

20.96

927

93.00

12

N 5 X S 8

13.90

1.62

0.32

19.50

847

94.00

13

Pam 117 X  DUN 22

14.50

1.58

0.29

18.01

805

90.00

14

Pam 117 X DUN 6

14.64

1.55

0.32

20.27

896

93.00

15

CSR 27 X DUN 22

14.26

1.51

0.31

20.50

919

93.00

16

CSR 27 X DUN 6

14.06

1.58

0.30

18.63

817

85.00

17

DUN 22 X Pam 117

14.42

1.55

0.29

18.38

820

92.00

18

DUN 22 X CSR 27

14.40

1.69

0.34

19.83

812

88.00

19

DUN 22 X DUN 6

13.44

1.63

0.32

19.31

821

85.00

20

DUN 22 X S 8

14.28

1.67

0.33

19.51

840

90.00

21

DUN 22 X N 5

13.60

1.63

0.32

19.34

827

88.00

22

DUN 6 X Pam 117

14.28

1.68

0.33

19.39

790

85.00

23

DUN 6 X CSR 27

13.84

1.63

0.31

18.99

774

87.00

24

DUN 6 X DUN 22

12.56

1.56

0.30

18.94

756

88.00

25

DUN 6 X S 8

13.30

1.49

0.30

19.73

903

94.00

26

DUN 6 X N 5

14.66

1.62

0.32

19.54

803

91.00

27

S 8 X DUN 22

14.68

1.56

0.29

18.64

803

93.00

28

S 8 X DUN 6

14.70

1.55

0.32

20.27

801

94.00

29

N 5 X DUN 22

14.90

1.62

0.33

20.07

819

90.00

30

N 5 X DUN 6

14.20

1.54

0.30

19.10

798

91.00

Control 1

SH6XNB4D2

14.90

1.55

0.29

18.73

818

95.00

Control 2

CSR6XCSR26

12.27

1.55

0.31

19.74

876

88.00

Control 3

CSR2XCSR27

12.80

1.58

0.32

20.00

878

89.00

MEAN

14.07

1.59

0.31

19.55

839.21

90.42

SD

0.71

0.05

0.02

0.85

43.52

3.09

 

Heterosis- Perusal of data reveals that the extent of heterosis in cocoon yield ranged from -13.62 (DUN6 X DUN22) to 13.76 (CSR27 X Pam 117). The heterosis ranged from -9.37 (N5 X Pam 117) to 5.36 (DUN22 X S8) in single cocoon weight; -12.12 (N5 X CSR27 & DUN22 X Pam 117) to 6.06 (S8 X Pam 117) in single shell weight; -9.84 (Pam 117 X DUN22) to 4.25 (N5 X Pam 117) in shell ratio; -5.66 (Pam 117 X S8) to 17.14 (CSR27 X DUN22) in filament length and -6.08 (DUN6 X Pam 117) to 8.05 (N5 X S8) in pupation rate. The average relative heterosis values ranged from-5.59 (DUN6 X DUN22) to 4.94 (S8 X CSR27) (Table 4). Evaluation index was also calculated on the values of relative heterosis (Table 5). Data reveals that the same hybrids ranked in the first six positions based on the values of average relative heterosis as well as the evaluation index values.

 

Table 4: Heterosis values of the hybrids during summer, 2019

Hybrids

Cocoon Yield by wt.

Single Cocoon Weight

Single Shell Weight

Shell Ratio

Filament Length

Pupation rate

Avg. Heterosis

CSR 27 X Pam 117

13.76

-1.21

1.49

1.96

7.09

2.22

4.22

CSR 27 X S 8

4.81

-1.26

-7.69

-5.95

-0.12

-3.95

-2.36

CSR 27 X N 5

9.31

-2.14

-12.12

-9.78

3.75

6.36

-0.77

Pam 117 X CSR 27

6.80

-3.03

1.49

3.94

5.85

5.56

3.44

Pam 117 X S 8

2.10

2.48

-3.03

-3.95

-5.66

-4.97

-2.17

Pam 117 X N 5

4.81

0.91

4.48

4.05

5.48

2.82

3.76

S 8 X CSR 27

7.38

0.00

1.54

2.20

12.29

6.21

4.94

S 8 X Pam 117

7.71

4.97

6.06

2.13

-2.16

-0.55

3.03

S 8 X N 5

1.92

-2.19

-7.69

-6.56

-2.04

4.60

-1.99

N 5 X CSR 27

-3.00

-5.20

-12.12

-8.59

4.61

6.36

-2.99

N 5 X Pam 117

-3.87

-9.37

-4.48

4.25

8.17

5.08

-0.04

N 5 X S 8

2.81

1.57

-1.54

-3.44

-1.45

8.05

1.00

Pam 117 X  DUN 22

0.80

-3.95

-12.12

-9.84

-2.78

1.12

-4.46

Pam 117 X DUN 6

4.39

-7.74

-4.48

3.00

9.87

2.76

1.30

CSR 27 X DUN 22

1.60

-7.08

-4.62

2.45

17.14

6.90

2.73

CSR 27 X DUN 6

2.82

-4.82

-9.09

-5.50

5.83

-3.95

-2.45

DUN 22 X Pam 117

0.24

-5.78

-12.12

-7.98

-0.97

3.37

-3.87

DUN 22 X CSR 27

2.60

4.00

4.62

-0.90

3.51

1.15

2.50

DUN 22 X DUN 6

-7.57

-1.51

-1.54

-1.05

4.12

-2.86

-1.74

DUN 22 X S 8

1.49

5.36

3.13

-2.77

1.14

2.86

1.87

DUN 22 X N 5

-5.23

0.00

-1.54

-3.01

-0.36

2.92

-1.20

DUN 6 X Pam 117

1.82

0.00

-1.49

-1.47

-3.13

-6.08

-1.73

DUN 6 X CSR 27

1.21

-1.81

-6.06

-3.68

0.26

-1.69

-1.96

DUN 6 X DUN 22

-13.62

-5.74

-7.69

-2.95

-4.12

0.57

-5.59

DUN 6 X S 8

-2.99

-8.02

-7.69

-0.20

10.39

5.62

-0.48

DUN 6 X N 5

4.79

-2.70

-3.03

-0.53

-1.77

4.60

0.23

S 8 X DUN 22

4.34

-1.58

-9.38

-7.10

-3.31

6.29

-1.79

S 8 X DUN 6

7.22

-4.32

-1.54

2.53

-2.08

5.62

1.24

N 5 X DUN 22

3.83

-0.61

1.54

0.65

-1.33

5.26

1.56

N 5 X DUN 6

1.50

-7.51

-9.09

-2.77

-2.39

4.60

-2.61

SH6XNB4D2

6.43

-4.91

-3.33

3.42

7.63

3.26

2.08

CSR6XCSR26

-6.90

-4.91

-4.62

-0.80

6.44

2.92

-1.31

CSR2XCSR27

-4.76

-3.66

-4.48

-1.26

9.54

2.89

-0.29

MEAN

1.77

-2.48

-3.89

-1.80

2.71

2.60

-0.18

MAXIMUM

13.76

5.36

6.06

4.25

17.14

8.05

4.94

MINIMUM

-13.62

-9.37

-12.12

-9.84

-5.66

-6.08

-5.59

SD

5.49

3.73

5.18

4.18

5.55

3.72

2.64

 

Table 5: Evaluation Index on Heterosis values of the hybrids during summer, 2019

Hybrid

Cocoon Yield by wt.

Single Cocoon Weight

Single Shell Weight

Shell Ratio

Filament Length

Pupation rate

Avg. Heterosis

CSR 27 X Pam 117

71.84

53.40

60.39

61.39

57.89

48.98

66.66

CSR 27 X S 8

55.54

53.27

42.66

42.46

44.90

32.39

41.74

CSR 27 X N 5

63.73

50.91

34.11

33.30

51.87

60.11

47.77

Pam 117 X CSR 27

59.16

48.53

60.39

66.12

55.66

57.96

63.69

Pam 117 X S 8

50.60

63.30

51.66

47.25

34.92

29.65

42.46

Pam 117 X N 5

55.54

59.09

66.16

66.39

54.99

50.59

64.92

S 8 X CSR 27

60.22

56.65

60.48

61.96

67.26

59.70

69.38

S 8 X Pam 117

60.82

69.97

69.21

61.79

41.23

41.53

62.15

S 8 X N 5

50.27

50.78

42.66

41.00

41.44

55.38

43.13

N 5 X CSR 27

41.31

42.71

34.11

36.15

53.42

60.11

39.36

N 5 X Pam 117

39.73

31.53

48.86

66.87

59.84

56.67

50.54

N 5 X S 8

51.89

60.86

54.54

48.47

42.50

64.65

54.47

Pam 117 X  DUN 22

48.23

46.06

34.11

33.16

40.11

46.02

33.78

Pam 117 X DUN 6

54.77

35.90

48.86

63.88

62.90

50.43

55.61

CSR 27 X DUN 22

49.69

37.67

48.59

62.56

76.00

61.56

61.03

CSR 27 X DUN 6

51.91

43.73

39.96

43.54

55.62

32.39

41.40

DUN 22 X Pam 117

47.21

41.15

34.11

37.61

43.37

52.07

36.01

DUN 22 X CSR 27

51.51

67.37

66.43

54.55

51.44

46.10

60.14

DUN 22 X DUN 6

32.99

52.60

54.54

54.19

52.54

35.32

44.11

DUN 22 X S 8

49.49

71.02

63.55

50.07

47.17

50.70

57.76

DUN 22 X N 5

37.25

56.65

54.54

49.50

44.47

50.86

46.12

DUN 6 X Pam 117

50.09

56.65

54.63

53.18

39.48

26.67

44.15

DUN 6 X CSR 27

48.98

51.80

45.81

47.89

45.59

38.47

43.25

DUN 6 X DUN 22

21.97

41.26

42.66

49.64

37.69

44.54

29.50

DUN 6 X S 8

41.33

35.15

42.66

56.22

63.84

58.12

48.86

DUN 6 X N 5

55.50

49.41

51.66

55.43

41.93

55.38

51.54

S 8 X DUN 22

54.68

52.41

39.40

39.71

39.15

59.92

43.90

S 8 X DUN 6

59.93

45.07

54.54

62.75

41.37

58.12

55.37

N 5 X DUN 22

53.75

55.01

60.48

58.25

42.72

57.15

56.58

N 5 X DUN 6

49.51

36.51

39.96

50.07

40.81

55.38

40.80

SH6XNB4D2

58.49

43.49

51.08

64.88

58.86

51.77

58.57

CSR6XCSR26

34.21

43.49

48.59

54.78

56.72

50.86

45.71

CSR2XCSR27

38.11

46.84

48.86

53.68

62.31

50.78

49.59

 

Heterobeltiosis- Perusal of data reveals that the extent of heterobeltiosis in cocoon yield ranged from -15.70 (DUN6 X DUN22) to 10.89 (CSR27 X Pam 117). The heterobeltiosis ranged from -11.83 (DUN6 X S8) to 3.68 (DUN22 X CSR27) in single cocoon weight; -14.71 (DUN22 X Pam 117 & Pam 117 X DUN22) to 3.13 (DUN22 X S8) in single shell weight; -10.58 (Pam 117 X DUN22) to 4.07 (N5 X Pam 117) in shell ratio; -7.60 (DUN6 X Pam 117) to 14.73 (CSR27 X DUN22) in filament length and -7.61 (DUN6 X Pam 117) to 5.68 (CSR27 X DUN22) in pupation rate. The average heterobeltiosis values ranged from-6.90 (Pam 117 X DUN22) to 3.08 (S8 X CSR27) (Table 6). Evaluation index was also calculated on the values of heterobeltiosis (Table 7). Data reveals that the same hybrids ranked in the first six positions based on the values of average heterobeltiosis as well as the evaluation index values.

 

Table 6: Heterobeltiosis values of the hybrids during summer, 2019

Hybrids

Cocoon Yield by wt.

Single Cocoon Weight

Single Shell Weight

Shell Ratio

Filament Length

Pupation rate

Avg.Heterob-

eltiosis

CSR 27 X Pam 117

10.89

-2.40

0.00

1.78

1.64

0.00

1.99

CSR 27 X S 8

4.53

-3.68

-9.09

-6.20

-5.47

-4.49

-4.07

CSR 27 X N 5

6.81

-2.44

-12.12

-10.09

-1.75

4.55

-2.51

Pam 117 X CSR 27

4.11

-4.19

0.00

3.76

0.47

3.26

1.24

Pam 117 X S 8

-0.22

-1.20

-5.88

-4.38

-5.93

-6.52

-4.02

Pam 117 X N 5

4.54

0.00

2.94

3.87

5.24

-1.09

2.58

S 8 X CSR 27

7.10

-2.45

0.00

1.92

6.28

5.62

3.08

S 8 X Pam 117

5.26

1.20

2.94

1.67

-2.44

-2.17

1.08

S 8 X N 5

-0.14

-4.88

-9.09

-7.14

-2.09

2.25

-3.52

N 5 X CSR 27

-5.22

-5.49

-12.12

-8.91

-0.93

4.55

-4.69

N 5 X Pam 117

-4.11

-10.18

-5.88

4.07

7.92

1.09

-1.18

N 5 X S 8

0.72

-1.22

-3.03

-4.04

-1.51

5.62

-0.58

Pam 117 X  DUN 22

-2.68

-5.39

-14.71

-10.58

-5.85

-2.17

-6.90

Pam 117 X DUN 6

3.24

-8.28

-5.88

0.65

4.80

1.09

-0.73

CSR 27 X DUN 22

-4.30

-7.36

-6.06

1.43

14.73

5.68

0.69

CSR 27 X DUN 6

-0.85

-6.51

-9.09

-7.82

5.28

-4.49

-3.91

DUN 22 X Pam 117

-3.22

-7.19

-14.71

-8.74

-4.09

0.00

-6.33

DUN 22 X CSR 27

-3.36

3.68

3.03

-1.88

1.37

0.00

0.47

DUN 22 X DUN 6

-9.80

-3.55

-3.03

-2.52

2.50

-4.49

-3.48

DUN 22 X S 8

-4.16

3.09

3.13

-3.99

-2.33

1.12

-0.52

DUN 22 X N 5

-8.72

-0.61

-3.03

-3.64

-3.73

2.33

-2.90

DUN 6 X Pam 117

0.71

-0.59

-2.94

-3.72

-7.60

-7.61

-3.63

DUN 6 X CSR 27

-2.40

-3.55

-8.82

-1.20

-0.26

-2.25

-3.08

DUN 6 X DUN 22

-15.70

-7.69

-9.09

-1.46

-5.62

-1.12

-6.78

DUN 6 X S 8

-6.21

-11.83

-9.09

-2.90

5.00

5.62

-3.24

DUN 6 X N 5

3.39

-4.14

-3.03

-2.64

-6.52

2.25

-1.78

S 8 X DUN 22

-1.48

-3.70

-9.38

-8.27

-6.63

4.49

-4.16

S 8 X DUN 6

3.67

-8.28

-3.03

-0.25

-6.86

5.62

-1.52

N 5 X DUN 22

0.00

-1.22

0.00

0.00

-4.66

4.65

-0.21

N 5 X DUN 6

0.14

-8.88

-9.09

-4.83

-7.10

2.25

-4.59

SH6XNB4D2

4.93

-8.82

-6.45

2.57

5.41

3.26

0.15

CSR6XCSR26

-11.34

-4.91

-6.06

-0.35

1.62

1.15

-3.32

CSR2XCSR27

-6.60

-4.24

-5.88

-1.04

5.15

1.14

-1.91

MEAN

-0.92

-4.15

-5.29

-2.57

-0.42

0.95

-2.07

MAXIMUM

10.89

3.68

3.13

4.07

14.73

5.68

3.08

MINIMUM

-15.70

-11.83

-14.71

-10.58

-7.60

-7.61

-6.90

SD

5.81

3.69

5.03

4.21

5.40

3.70

2.62

 

Table 7: Evaluation Index on Heterobeltiosis values of the hybrids during summer, 2019

Hybrids

Cocoon Yield by wt.

Single Cocoon Weight

Single Shell Weight

Shell Ratio

Filament Length

Pupation rate

Avg. Heterob-

eltiosis

CSR 27 X Pam 117

70.33

54.74

60.52

60.33

53.81

47.43

65.48

CSR 27 X S 8

59.38

51.27

42.45

41.38

40.65

35.30

42.38

CSR 27 X N 5

63.30

54.63

36.42

32.14

47.54

59.73

48.33

Pam 117 X CSR 27

58.66

49.89

60.52

65.04

51.65

56.24

62.61

Pam 117 X S 8

51.20

57.99

48.83

45.70

39.80

29.81

42.55

Pam 117 X N 5

59.40

61.25

66.36

65.30

60.48

44.49

67.76

S 8 X CSR 27

63.80

54.61

60.52

60.67

62.41

62.62

69.65

S 8 X Pam 117

60.64

64.50

66.36

60.07

46.26

41.57

62.01

S 8 X N 5

51.34

48.02

42.45

39.14

46.91

53.51

44.48

N 5 X CSR 27

42.60

46.37

36.42

34.94

49.06

59.73

40.01

N 5 X Pam 117

44.51

33.66

48.83

65.77

65.44

50.38

53.39

N 5 X S 8

52.82

57.94

54.49

46.51

47.98

62.62

55.70

Pam 117 X  DUN 22

46.97

46.64

31.27

30.97

39.94

41.57

31.58

Pam 117 X DUN 6

57.16

38.81

48.83

57.65

59.67

50.38

55.11

CSR 27 X DUN 22

44.18

41.30

48.47

59.50

78.06

62.78

60.52

CSR 27 X DUN 6

50.12

43.60

42.45

37.53

60.56

35.30

42.96

DUN 22 X Pam 117

46.04

41.76