표제지

목차

I. 서언 11

II. 연구사 14

1. 페튜니아 일대 잡종에서 생육과 개화관련 형질의 상호관계 및 조합능력 14

2. 페튜니아의 꽃 관련 형질 유전 15

3. 페튜니아 온도감응형 웅성불임 계통의 선발과 이를 이용한 일대잡종 20

III. 페튜니아 일대 잡종에서 생육과 개화관련 형질의 상호관계 및 조합능력 22

1. 서언 22

2. 재료 및 방법 24

3. 결과 26

4. 고찰 39

5. 적요 41

IV. 페튜니아의 꽃 관련 형질 유전 42

1. 서언 42

2. 재료 및 방법 45

3. 결과 47

4. 고찰 56

5. 적요 61

V. 페튜니아 온도감응형 웅성불임 계통의 선발과 이를 이용한 일대잡종 62

1. 서언 62

2. 재료 및 방법 65

3. 결과 69

4. 고찰 81

5. 적요 84

VI. 종합고찰 85

VII. 인용문헌 93

VIII. 적요 102

1. 페튜니아 일대 잡종에서 생육과 개화관련 형질의 상호관계 및 조합능력 102

2. 페튜니아의 꽃 관련 형질 유전 103

3. 페튜니아 온도감응형 웅성불임 계통의 선발과 이를 이용한 일대잡종 104

ABSTRACT 106

List of Tables

Table 1. List of major nuclear genes for flower characters in Petunia hybrida. 16

Table 2. Growth characteristics of petunia parents used in the experiment. 26

Table 3. Correlation coefficients between growth characters in parents and F₁ hybrids. 27

Table 4. Analysis of variance for combining ability and the estimates of variance components for growth characters in Petunia hybrida. 29

Table 5. GCA effects of 6 parents for growth characters in Petunia hybrida. 30

Table 6. SCA effects for growth characters of 6-parent diallel cross in Petunia hybrida. 31

Table 7. Heritability of 7 growth characters in Petunia hybrida 32

Table 8. Growth and flowering characteristics of petunia parents used in the experiment. 33

Table 9. Correlation coefficients between growth and flowering characters in parents and F₁ hybrids. 33

Table 10. Analysis of variance for combining ability and the estimates of variance components for growth and flowering characters in Petunia hybrida. 35

Table 11. GCA effects of 6 parents for growth and flowering characters in Petunia hybrida. 36

Table 12. SCA effects for growth and flowering characters of 6-parent diallel cross in Petunia hybrida. 37

Table 13. Heritability of growth and flowering characters in Petunia hybrida. 38

Table 14. Color intensity of corolla of 5 parents and their hybrids in Petunia hybrida. 47

Table 15. Segregation of corolla color in F₂ and BC₁F₁ of the reciprocal cross in Petunia hybrida. 49

Table 16. Segregation of corolla color in F₂ of the C×D (Blue×White) in Petunia hybrida. 51

Table 17. Flower diameter of parents and their hybrids in Petunia hybrida. 53

Table 18. Segregation of flower size in F₂ and BC₁F₁ of the reciprocal cross in Petunia hybrida. 53

Table 19. Segregation of flower shape in F₂ and BC₁F₁ of the reciprocal cross in Petunia hybrida 55

Table 20. The number of seeds per capsule, germination percentage, days to flowering, and character uniformity of the male sterile lines. 70

Table 21. The growth characteristics of selected male sterile lines in Petunia hybrida. 71

Table 22. The flowering characteristics of selected male sterile lines in Petunia hybrida. 72

Table 23. The rate of pollination by self-crossing during spring and summer of the selected male sterile lines. 73

Table 24. The effect of temperature on pollen grain production of the selected male sterile lines. 74

Table 25. The growth and flowering characteristics of the male parents. 75

Table 26. The number of seeds per capsule, germination percentage, and days to flowering of the cross combinations utilizing MS lines. 76

Table 27. The flowering characteristics of the cross combinations utilizing male sterile lines. 78

Table 28. The growth characteristics of the cross combinations utilizing male sterile lines. 79

Table 29. Heterosis effect for flowering and growth of the cross combinations utilizing male sterile lines. 80

List of Figures

Fig. 1. Pedigree of the lines used in correlation coefficient analysis and combining ability test in Petunia hybrida. 25

Fig. 2. Effect of crossed A×D on the leaf shape in Petunia hybrida. 28

Fig. 3. Effect of crossed D×A on the plant height and number of flowers in Petunia hybrida. 34

Fig. 4. Effect of crossed F×G on the stem diameter and internode length in Petunia hybrida. 34

Fig. 5. Pedigree of the lines used in the inheritance of flower color in Petunia hybrida. 46

Fig. 6. Reciprocal effects of corolla color of A×D (Pink×White, left) and D×A (White×Pink) in Petunia hybrida. 50

Fig. 7. Segregation of corolla color in F₂ of the G× (Red×hite) in Petunia hybrida. 50

Fig. 8. Lightness (L*) of corolla color in F₁ and F₂ population of the G×D (Red×White) in Petunia hybrda. 51

Fig. 9. Segregation of corolla color in F₂ of the F×C (Yellow×Blue) in Petunia hybrida. 52

Fig. 10. Segregation of corolla color in F₂ of the C×D (Blue×White) in Petunia hybrida. 52

Fig. 11. Segregation of flower size in F₂ population of G×D (Small×Large) in Petunia hybrida. 54

Fig. 12. Segregation of flower shape in F₂ of F×G (Round×Star) in Petunia hybrida. 54

Fig. 13. Pedigree of the male sterile lines in Petunia hybrida used in the experiment. 67

Fig. 14. Pedigree of the male parent lines in Petunia hybrida used in the experiment. 68

Fig. 15. Stamens of male fertile (left) and male sterile (middle and right). 69

Fig. 16. Pollen grains of male sterile (left) and male fertile (light, ×200). 69

Fig. 17. Pedigree of F₁ hybrid breeding used male sterile lines in Petunia hybrida. 83

 To test the correlation, combining ability and heterosis in F₁ hybrids in Petunia hybrida, six inbred lines with different growth and flowering characteristics were diallel crossed and investigated the leaf length, leaf width, number of leaves, leaf area, number of branches, fresh weight, dry weight, plant height, stem diameter, internode length, peduncle length, flower height and number of flowers.

To analyze the inheritance of corolla color, flower size and flower shape in F₁ and F₂ generation, five inbred lines with different corolla color and flower type were inter-crossed, and investigated the expression appearance in F₁ and segregation ratio in F₂. To test the possibility of F₁ hybrids in Petunia hybrida utilizing male sterile (MS) lines, investigated the characteristics and heterosis of combinations crossed between the MS lines of maternal plant and the normal inbred (S7) of paternal plant.

1. Correlation and Combining Ability of Growth and Flowering in F₁ Hybrids by diallel cross in Petunia hybrida

The correlation and combining abilities of growth and flowering characters were studied in the combination of 15 crosses F₁ from the partial six-parent diallel cross in Petunia hybrida.

The leaf area, fresh weight, and dry weight showed high positive correlation together with the other growth characters such as leaf length, leaf width, number of branches, and number of leaves. The mean squares of general combining ability (GCA) and specific combining ability (SCA) were highly significant for all the growth characters. The mean square values of GCA were greater than those of SCA for all the characters, showing preponderance of additive gene actions for these characters. GCA effect was high in the lines of D and G for leaf length and fresh weight, and in the lines of C and D for number of branches, number of leaves, leaf area, and fresh weight. The crosses of DxE, DxG, and ExG exhibited high SCA effect for all the growth characters such as leaf length, leaf width, number of branches, number of leaves, leaf area, fresh weight, and dry weight. The broad sense heritability was generally high compared to narrow sense one in the 7 characters. The highest heritability of the broad and narrow sense was shown in the leaf width and dry weight.

The plant height showed highly positive correlation with stem diameter, internode length, and number of flowers. The mean squares of general combining ability (GCA) and specific combining ability (SCA) were highly significant for all the growth and flowering characters. The mean square values of GCA were greater than those of SCA for all the characters, showing preponderance of additive gene actions for these characters. The lines of G and C for plant height and A, D, and G for number of flowers showed relatively high GCA effects. The crosses of ExG, AxG, and DxE exhibited high SCA effects on plant height, stem diameter, internode length, peduncle length, and number of flowers. The broad sense heritability was generally high compared to narrow sense one. Plant height and peduncle length of the characters related to growth and flowering showed the highest heritability of the broad and narrow sense.

2. Inheritance of Flower Characters in Petunia hybrida

This experiment was conducted to determine inheritance of corolla color, and to determine effects of inheritance on the flower size between a large flower (glandiflora) and a small flower (multiflora), and the flower shape among star, round, and pentagon ones by utilizing the inter crosses of the inbred lines (S7) in Petunia hybrida.

Five inbred lines of distinct corolla colors, such as the pink, purple, white, red, and yellow were inter crossed by a diallel cross. Almost all hybrids showed medium of color intensity for lightness (L*) and value (V). Segregation observed in the progenies among parents with white, red, and pink corolla indicated monogenic inheritance, but that both yellow x purple corolla and purple x white corolla showed digenic inheritance.

The larger showed as complete dominant in F₁ generation, and large to small sized flowers appeared a ratio of 3 to 1 in F₂. As for flower shape, it was shown that the intermediate hybrid in F₁, and segregated to 1 maternal, 2 intermediate, and 1 paternally shaped flower in F₂, indicating incomplete dominant pattern.

3. Selection of Male Sterile Lines Response to the Temperature, and Their F₁ Hybrids in Petunia hybrida

This experiment was carried out to select male sterile (MS) lines, determine types of MS by exposing to various temperatures and evaluate F₁ hybrids utilizing inbred lines of petunia under high temperature for the purpose of saving labour in producing seeds.

The thirteen MS lines with different flower colors and growth characteristics derived from several kinds of commercial cultivar were selected and self-crossed at low temperature during spring from 1993 to 2000. Among the 13 MS lines, 3 lines with light pink flower color, 6 lines with pink, a line with deep pink, a line with purple, a line with deep purple, and a line with red flower color. The 5 lines showed below 15.0cm and 3 lines with above 20.0 cm in plant height.

To distinguish the type of MS, all the selected MS lines were exposed to the temperature of 15, 20, 25, and 30℃ in the growth chamber. When exposed to the temperature of 15℃, all the lines had pollen grains in the anther, indicating of fertile nature, mean while almost all the lines had a few pollen grains at 20℃ under microscopic observation. All the lines, however, had no pollen at 25℃ and 30℃. In March and April, all the lines produced seeds by selfing them in a greenhouse with night temperature of 15~20℃. However, the percentage of fertility was low (20~75%) as well as the number of seeds in a capsule was low (less than 100) compared to those of normal inbred lines. In summer, from July to August, all the lines of MS did not have pollen grains, thus they did not produce seeds by self-pollination. The results of this experiment, therefore, suggest that the type of MS in petunia lines can be classified as cytoplasmic male sterility.

The F₁ hybrids by crossing between the MS lines of maternal plant and the normal inbred (S7) of paternal plant, which were self-pollinated every year from 1993 to 2000, showed uniform growth and flowering characteristics. The 11 F₁ combinations including 'MS-1 x MF-11' produced above 150 seeds per a capsule and germinated above 80% from the seeds with high heterosis in growth and flowering. These F₁ hybrids are possible recommended for saving labour in producing many seeds having uniform growth and flowering characteristics.