CHAPTER 6 Hybridization Breeding
杂交育种
Hybridization – Crossing
? Sexual Crossing
? Asexual Crossing
? Distant Crossing - interspecific Crossing
? Intraspecific Crossing – inter-varietal Crossing
In this chapter,Hybridization Breeding
i.e,CROSS BREEDING
1,What is Cross Breeding? P.85
Crossing with different genotypes
Trials for identification and Selection
New cultivar(s)
Types of Cross Breeding,
§ 1 The Conception and Significance of Cross
Breeding
杂交育种的概念和意义
? Combination Breeding 组合育种,Combination of diff,genes
? Transgression Breeding 超亲育种, Accumulation of minor poly-
genes
2,Significance of Cross Breeding
The most widely used breeding method in present
The most fruitful breeding method in present (p.86)
The combined use with other breeding methods
§ 2 Selection and Combination of Parents
亲本选择和选配
1,Selection of Parents 亲本选择
The Importance
Pre-condition of successful breeding
The Principles p.87
Large number of source materials
Obvious objective characters
Local popularized varieties
Genetic characteristics of the objective characters
2,Combination of Parents
(1) Significance
Key to successful breeding,
(2) Principles
1) More advantages,less disadvantages; Complementary
2) Large genetic differences
3) High Combining ability,
GCA,Additive gene effects
SCA,Heterosis effects (non-additive)
Good cultivars are not always good parents
4) Salient objective characters in one or both parents,with a high
inheritability
5) Select one locally popularized cultivar as one of the parents
(3) Successful Selection and combination of parents in cross breeding
Tab,6-1,p,90
§ 3 Modes of Cross and the Techniques
杂交方式和技术
1,Modes of Cross,Number of parents
Modes of combination
(1) Single Cross
A× B or A/B (Cytoplasm from A)
B× A or B/A (Cytoplasm from B)
(2) Multiple Cross
1） Three way cross
(A× B)× C or A/B//C （ Cytoplasm of A,C=1/2)
2） Double Cross
(A× B)× (C× D) or A/B//C/D
(A× B)× (A× C) or A/B//A/C (A=1/2)
3） Tetra Cross
A/B//C/3/D (D=1/2)
4) Convergent Cross
A/B//C/D /3/ E/F//G/H
(3) Backcross
A/B//A A/B//B
(4) Multiple Parental Cross
A/(B+C+D+E)
2,Techniques of Crossing
(1) Regulation/timing of flowering stages
(2) Emasculation
(3) Pollination
(4) Post management
§ 4 Selection of the Offspring
杂种后代的选育
1,Cultivation of the offspring
? Assurance of the offspring for normal growth
? Uniformity of cultivation and management
? Appropriate conditions for identification of special
characters (i.e,disease/stress resistance)
2,Selection of the offspring (Methods)
(1) Pedigree Selection
A,Outline of the Procedure
1) F1 generation Selection of combinations
2) F2 generation Large segregation,the key
selection generation,large population,Individual
selection,sufficient selected plants
3) F3 generation Plant rows,individual selection
based on performance of plant families
4) F4 and later generations growing of groups of
plant families,selection for uniform,stable families,
identified in line plots (sequentially planted with CK
plots inserted)
B,The Basis and Effect of Selection in Different Generations
1) The inheritability of Characters
? Characters of high H2 Select in Lower generations
? Characters of low H2 Select in Higher generations
2) Individual and family (line) performance
Lower H2 vs Higher H2
3) Field evaluation plus indoor evaluation
Combined selection
(2) Bulk Selection (混合选择）
Bulk sowing of F2 – F4…
Removal of only the evident inferior individuals
Bulk harvest of seeds for next generation
Selection in basically stable populations (F5 – F8),
Individual selection for one or two generations
The best line for yield trials
New cultivar for release
? COMPARISON OF PEDIGREE SELECTION TO BULK
SELECTION (系谱选择法与混合选择法比较）,
1) Pedigree selection
? Early selection (F2); earlier concentrated on fewer
superior plant lines
? Clear pedigree History in each selected family (line),
Breeding experience
? Shorter breeding term
? Favorable for qualitative traits or highly inheritable
traits
? High probability of lost of desirable genes; Heavy field
work
2) Bulk Selection
? Bulk growing
? Selection in late generations,less work in field
? Quantitative traits and lowly inheritable traits
favorable,good for accumulation of poly-genes
? No pedigree records for selected lines
? Affection of natural selection
? Long term of breeding
(3) Other Selection Methods
1) Derived line (pedigree) method (衍生系统法）
2) Single seed descent method （单粒传法）
3) Group bulk selection method （集团混合法）
……
( Left for self study)
1,The Procedure of Cross breeding
§ 5 Breeding Procedure and the Methods of
Acceleration of the breeding progress
杂交育种程序和加快育种进程的方法
F0 Parents
F1 Hybrid
F5-6 Stable lines,Plant
rows,Yield test
F4 Families groups,
Stable lines
F2 Population
F3 Families(plant rows)
F7-10 Stable lines,
Yield trials
Selection of parents,
Crossing
Big segregation,Selection of
desirable single plants
Selection of Combinations
Mainly yield tests,Identifying for
superior lines
Similar to work in F3
Plant row test,Selection of
superior plants in suerior rows
Replicated yield trials,
Regional Trials,Productive
trials
Pr
oc
ed
ur
e o
f P
ed
igr
ee
M
eth
od
2,Methods to Accelerate Breeding Progress
(1) Faster generation progress 加快繁育世代进程
1) Adding generations in other places
2) Adding generations locally
3) Adding generations with artificial facilities
(2) Faster Trial Progress 加快试验进程
1) Earlier yield test
2) Over passing generations
3) Multiple location test
§ 6 Backcross Breeding
回交育种
1,Concept of Backcross
Backcross A/B//A…
Backcross Breeding p.104
A
Current parent
B
Non-current
parent
×
F1× A
BC1F1× A
BC2F1× A
BC3F1× A
BC4F1× A
回交育种的程序
2,Particular Characteristics and Significance of
Backcross Breeding 回交育种的特点和意义
1) Variation controllable,selection possible in alien places
2) Easy in selection of objective characters
3) Favorable in breaking genetic linkage
4) The resultant varieties are Easily popularized
Shortcomings,
Efficient only for improvement of a few Characters
The Significances,
? Transfer of disease/pest resistant genes
? Transfer of male sterility
? Improvement of a few demerits in current cultivars
without changing the adaptation
3,Brief Techniques in Backcross Breeding
回交育种技术要点
(1) Selection of Parents
Non-current parent
Current parent
(2) Cross,Backcross and Selection (Breeding procedure)
Dominant genes (cross / backcross continued) Fig,6.5
Recessive genes (Cross / backcross alternated) Fig,6.6
(p,109-110)
(3) Times of backcross
Requirements for improvement
Linkage of genes
Attribute of characters
(3) Number of Plants for Backcross
Number of plants,
ρ ）（
α ）
-1lg
-1l g (?m
Number of genes to be transferred
Gene pairs 1 2 3 4 5 6
Frequency of
Genotype 1/2 1/4 1/8 1/16 1/32 1/64
0.95 4.3 10.4 22.4 46.3 95 191
Probability
0.99 6.6 16.0 34.5 71.2 146 296
4,Other Forms of Backcross Breeding
回交育种的其他方式
(1) Stepwise Backcross Multiple resistant breeding
(2) Convergent Backcross Fig.6.7,p,113
(3) Backcross Pedigree Method
(Self study part)
Class Test (2)
Explanation of Concepts,
1,Natural selection
2,Artificial selection
3,Individual selection
4,Bulk selection (Mass selection)
5,Group bulk selection
Till Next Chapter
杂交育种
Hybridization – Crossing
? Sexual Crossing
? Asexual Crossing
? Distant Crossing - interspecific Crossing
? Intraspecific Crossing – inter-varietal Crossing
In this chapter,Hybridization Breeding
i.e,CROSS BREEDING
1,What is Cross Breeding? P.85
Crossing with different genotypes
Trials for identification and Selection
New cultivar(s)
Types of Cross Breeding,
§ 1 The Conception and Significance of Cross
Breeding
杂交育种的概念和意义
? Combination Breeding 组合育种,Combination of diff,genes
? Transgression Breeding 超亲育种, Accumulation of minor poly-
genes
2,Significance of Cross Breeding
The most widely used breeding method in present
The most fruitful breeding method in present (p.86)
The combined use with other breeding methods
§ 2 Selection and Combination of Parents
亲本选择和选配
1,Selection of Parents 亲本选择
The Importance
Pre-condition of successful breeding
The Principles p.87
Large number of source materials
Obvious objective characters
Local popularized varieties
Genetic characteristics of the objective characters
2,Combination of Parents
(1) Significance
Key to successful breeding,
(2) Principles
1) More advantages,less disadvantages; Complementary
2) Large genetic differences
3) High Combining ability,
GCA,Additive gene effects
SCA,Heterosis effects (non-additive)
Good cultivars are not always good parents
4) Salient objective characters in one or both parents,with a high
inheritability
5) Select one locally popularized cultivar as one of the parents
(3) Successful Selection and combination of parents in cross breeding
Tab,6-1,p,90
§ 3 Modes of Cross and the Techniques
杂交方式和技术
1,Modes of Cross,Number of parents
Modes of combination
(1) Single Cross
A× B or A/B (Cytoplasm from A)
B× A or B/A (Cytoplasm from B)
(2) Multiple Cross
1） Three way cross
(A× B)× C or A/B//C （ Cytoplasm of A,C=1/2)
2） Double Cross
(A× B)× (C× D) or A/B//C/D
(A× B)× (A× C) or A/B//A/C (A=1/2)
3） Tetra Cross
A/B//C/3/D (D=1/2)
4) Convergent Cross
A/B//C/D /3/ E/F//G/H
(3) Backcross
A/B//A A/B//B
(4) Multiple Parental Cross
A/(B+C+D+E)
2,Techniques of Crossing
(1) Regulation/timing of flowering stages
(2) Emasculation
(3) Pollination
(4) Post management
§ 4 Selection of the Offspring
杂种后代的选育
1,Cultivation of the offspring
? Assurance of the offspring for normal growth
? Uniformity of cultivation and management
? Appropriate conditions for identification of special
characters (i.e,disease/stress resistance)
2,Selection of the offspring (Methods)
(1) Pedigree Selection
A,Outline of the Procedure
1) F1 generation Selection of combinations
2) F2 generation Large segregation,the key
selection generation,large population,Individual
selection,sufficient selected plants
3) F3 generation Plant rows,individual selection
based on performance of plant families
4) F4 and later generations growing of groups of
plant families,selection for uniform,stable families,
identified in line plots (sequentially planted with CK
plots inserted)
B,The Basis and Effect of Selection in Different Generations
1) The inheritability of Characters
? Characters of high H2 Select in Lower generations
? Characters of low H2 Select in Higher generations
2) Individual and family (line) performance
Lower H2 vs Higher H2
3) Field evaluation plus indoor evaluation
Combined selection
(2) Bulk Selection (混合选择）
Bulk sowing of F2 – F4…
Removal of only the evident inferior individuals
Bulk harvest of seeds for next generation
Selection in basically stable populations (F5 – F8),
Individual selection for one or two generations
The best line for yield trials
New cultivar for release
? COMPARISON OF PEDIGREE SELECTION TO BULK
SELECTION (系谱选择法与混合选择法比较）,
1) Pedigree selection
? Early selection (F2); earlier concentrated on fewer
superior plant lines
? Clear pedigree History in each selected family (line),
Breeding experience
? Shorter breeding term
? Favorable for qualitative traits or highly inheritable
traits
? High probability of lost of desirable genes; Heavy field
work
2) Bulk Selection
? Bulk growing
? Selection in late generations,less work in field
? Quantitative traits and lowly inheritable traits
favorable,good for accumulation of poly-genes
? No pedigree records for selected lines
? Affection of natural selection
? Long term of breeding
(3) Other Selection Methods
1) Derived line (pedigree) method (衍生系统法）
2) Single seed descent method （单粒传法）
3) Group bulk selection method （集团混合法）
……
( Left for self study)
1,The Procedure of Cross breeding
§ 5 Breeding Procedure and the Methods of
Acceleration of the breeding progress
杂交育种程序和加快育种进程的方法
F0 Parents
F1 Hybrid
F5-6 Stable lines,Plant
rows,Yield test
F4 Families groups,
Stable lines
F2 Population
F3 Families(plant rows)
F7-10 Stable lines,
Yield trials
Selection of parents,
Crossing
Big segregation,Selection of
desirable single plants
Selection of Combinations
Mainly yield tests,Identifying for
superior lines
Similar to work in F3
Plant row test,Selection of
superior plants in suerior rows
Replicated yield trials,
Regional Trials,Productive
trials
Pr
oc
ed
ur
e o
f P
ed
igr
ee
M
eth
od
2,Methods to Accelerate Breeding Progress
(1) Faster generation progress 加快繁育世代进程
1) Adding generations in other places
2) Adding generations locally
3) Adding generations with artificial facilities
(2) Faster Trial Progress 加快试验进程
1) Earlier yield test
2) Over passing generations
3) Multiple location test
§ 6 Backcross Breeding
回交育种
1,Concept of Backcross
Backcross A/B//A…
Backcross Breeding p.104
A
Current parent
B
Non-current
parent
×
F1× A
BC1F1× A
BC2F1× A
BC3F1× A
BC4F1× A
回交育种的程序
2,Particular Characteristics and Significance of
Backcross Breeding 回交育种的特点和意义
1) Variation controllable,selection possible in alien places
2) Easy in selection of objective characters
3) Favorable in breaking genetic linkage
4) The resultant varieties are Easily popularized
Shortcomings,
Efficient only for improvement of a few Characters
The Significances,
? Transfer of disease/pest resistant genes
? Transfer of male sterility
? Improvement of a few demerits in current cultivars
without changing the adaptation
3,Brief Techniques in Backcross Breeding
回交育种技术要点
(1) Selection of Parents
Non-current parent
Current parent
(2) Cross,Backcross and Selection (Breeding procedure)
Dominant genes (cross / backcross continued) Fig,6.5
Recessive genes (Cross / backcross alternated) Fig,6.6
(p,109-110)
(3) Times of backcross
Requirements for improvement
Linkage of genes
Attribute of characters
(3) Number of Plants for Backcross
Number of plants,
ρ ）（
α ）
-1lg
-1l g (?m
Number of genes to be transferred
Gene pairs 1 2 3 4 5 6
Frequency of
Genotype 1/2 1/4 1/8 1/16 1/32 1/64
0.95 4.3 10.4 22.4 46.3 95 191
Probability
0.99 6.6 16.0 34.5 71.2 146 296
4,Other Forms of Backcross Breeding
回交育种的其他方式
(1) Stepwise Backcross Multiple resistant breeding
(2) Convergent Backcross Fig.6.7,p,113
(3) Backcross Pedigree Method
(Self study part)
Class Test (2)
Explanation of Concepts,
1,Natural selection
2,Artificial selection
3,Individual selection
4,Bulk selection (Mass selection)
5,Group bulk selection
Till Next Chapter
