Best of presentation prepared for better understanding of biparental mating design under the guidance of Dr. S.K. Singh.

1. Biparental
Mating
Lokesh Gour
DEPARTMENT OF PLANT BREEDING & GENETICS
JAWAHARLAL NEHRU KRISHI VISHWA VIDYALAYA
JABALPUR , MADHYA PRADESH (INDIA)
Guided by:-
Dr. S.K. Singh, Assistant Professor

2. Introduction
 Comstock R.E. and Robinson H.F. (1948,1952)
 Commonly F2 generation of pure lines strains are selected and crossed
in definite fashion
 The paper of them were been cited in over 105 publications since 1961.
Three deigns of
biparental
mating

3. ☺ It involves F2, P1 and P2 generations of a single cross.
☺ It requires 3 crop season for generating material and fourth season for
evaluation
☺ It provides information about additive and dominance components of
genetic variance
☺ It helps in choice of breeding procedure for genetic improvement of
polygenic characters
☺ Analysis is based on second order statistics
Characteristics

4. Genetical assumptions of biparental cross
 Random distribution of genotypes in relation to variation
 Random choice of plants for mating
 Regular diploid segregation
 Absence of epistasis
 Absence of linkage
 Equal survival of all genotypes
 Absence of maternal effects
 Lack of multiple allelism

5. North Carolina
Design 1
North Carolina
Design 2
North Carolina
Design 3
Biparental Mating
Nested Design
&
Hierarchical
design
Factorial
Design
-

6. Material used for Biparental Mating
Population Parent 1
Parent 2
F2
Progenies
Half sib
(male group)
Full sib
(females/males)

7. Steps of biparental mating
1. Selection of parents Hmm !!!
Having
contrasting
characters

8. 2. Making Original Cross
F1 seed
P1 P2

9. 3. Growing F1 and F2 Progeny
F2 seed
F1 F1

10. 4. Making Cross in F2
F2 Population now
crossing done in
definite fashion
F2 Seed

11. 5. Evaluation of Crosses
Replicated Trial
For
Observations
Randomly selecting

12. 6. Biometrical Analysis
Computation of Sum of
Squares
Genetical Interpretations
Analysis of Variance
(ANOVA)
Component of Variances

14. Nested Design
Males Females
3
4
9
10
11
12
13
14
15
16
Males Females
1
2
1
2
3
4
5
6
7
8

15. Factorial Design
Males Females
F1 F2 F3 F4
M1 X X X X
M2 X X X X
M3 X X X X
M4 X X X x

16. North Carolina Design 3
Males Females
P1 P2
Set I
M1 X X
M2 X X
M3 X X
M4 X X
Set II
M5 X X
M6 X X
M7 X X
M8 X X

17. Variances analysed in NCD
The variance among single crosses is
divided into
Two
fractions
Three
fractions
Two
fractions
(i) Variance among males -
which is equal to ¼ VA
(ii) Variance due to females –
which is equal to ¼ VA + ¼
VD
(i) Variance due males -
equals to ¼ VA
(ii) Variance due to females -
equals to ¼ VA
(iii) Variance due to male x
female - equals to ¼ VD
(i) Variance among males -
equals to ½ VA
(ii) Variance due to male x
female - equals to ½ VD

18. Evaluated Features of NCD Design
1. Each male is mated to a different set of females
2. Equal to the number of females used in set x number of
sets
3. Total number of crosses is equal to ns
4. Presence of maternal effect
1. Each male is mated to the same set of females
2. Total number of cross is equal to mf
3. Evaluation is equal to mns
4. Presence of maternal effect
1. Each male is mated to the same set of females
2. Each sat consists of 2m crosses
3. Evaluation is equal to 2ns
4. Absence of maternal effect
NCD I
NCD II
NCD III

20. 1. Maternal effect
NCD I NCD II NCD III
?

21. 2. Area requirement
NCD I
NCD II
NCD III
More
Medium
Least

22. Use of North Carolina Design
1. Effective in breaking undesirable linkages- mating randomly selected plants
in segregating population
2. Selection of suitable breeding procedure- for polygenic characters
3. Can be used for self as well as cross pollinated species
4. Creation of variability- creating heterozygosity
5. Biparental mating permits evaluation of segregating (F2 or later generation)
population of an individual cross made between two inbred lines
6. It provides information about two components of genetic variance i.e
additive and dominance variance
7. This technique helps in the selection of suitable breeding procedures

23. Problems of North Carolina Design
1. Not applicable to the segregating populations of three way, double and multiple
crosses
2. Not permit several segregating crosses simultaneously
3. Does not provide information about the epistatic variance
4. Analysis is difficult as it based on second order statistics

25. S.NO NCD 1 NCD 2 NCD 3
1. Each male is mated to a
different group of females
Each male is mated to a
same group of females
Each male is mated to both
inbred parents of original
cross.
2. ‘f’ crosses were obtained ‘mf’ crosses were obtained ‘2m’crosses were obtained
3. Variance is divided into 2
fractions , due to males
and due to females.
Variance is divided into 3
fractions, due to males, due
to females and due to
male x female
Variance is divided into 2
fractions due to male and
due to male x female
4. Variance due to male
provide an estimate of
additive variance (D)
Variance due to male and
female provide an esimate
of additive variance (D)
Variance due to male
provide an estimate of
additive variance (D)
5. Variance due to female
provide an estimate of
additive (D) and
dominance variance (H)
Variance due male x female
provide an estimate of
dominance variance (H)
Variance due to male x
female provide an estimate
of dominance variance(H)

26. NCD 1 NCD 2 NCD 3
6. Requires 10 – 12 times
more area than design 3.
Requires 2-4 times more
area than design 3.
Requires much less area
than design 1 and 2.
7. Influenced by the presence
of maternal effects.
Influenced by the presence
of maternal effects.
Not affected by the
presence of maternal
effects.
8 Involves F2 Plants in
crossing
Involves F2 Plants in
crossing
Involves F2, P1 and P2
Plants in crossing
9. This is least powerful
design
This is intermediate design This is most powerful
design