ROLE OF INHERITANCE IN CROP IMPROVEMENT

1. WELCOME

2. Presented By :
V. Rathod
ROLE OF INHERITANCE IN
CROP IMPROVEMENT
1

3. Content
Introduction
Types of Genetic Crosses
Types of Inheritance
Role of Inheritance
Review of Research Work
Conclusion
2

4. INHERITANCE
3

5. Inheritance- Genetic trait or characteristics that
is passed from parent to the next generation of
offspring.
Austrian monk Gregor J. Mendel who
formulated fundamental laws of heredity in early
1860s
 His work with garden pea (Pisum sativum)
 Over seven years, he made crosses with
24,034 plants

Called the “Father of Genetics’’
Gregor J. Mendel
(1822-1884)
INTRODUCTION
4

6. • alleles on corresponding
positions of homologous
chromosomes are
identical e.g. BB or bb
HOMOZYGOUS
• pairs of different alleles
are present on
corresponding positions
of homologous
chromosomes e.g. Bb
HETEROZYGOUS
5

7. Genotype & Phenotype
Genotype -
Describes the genetic
make-up (all of the
genes) of an
individual.
(e.g. RR, Rr, rr)
Phenotype - the
physical appearance
of a trait.
(e.g. red, white)
6

8. Which is the dominant allele?
Allele for purple colour [100% purple in F1 generation]
7

9.  •Dominant allele does not
completely express itself
F-1 progeny is the
intermediate of the two parents
 • For example, A cross
between red and white flowered
plants produced plants with
intermediate flower colour i.e.
pink colour in F1 and a
modified ratio of 1 red: 2 pink: 1
White in F2.
Incomplete dominance
8

10. CO-DOMINANCE
There are several genes that have two different dominant traits
If these two dominant traits are expressed at the same time we
call it codominance
Both traits are equally dominant
Co-Dominance genes are genes that express both alleles in the
pairing.
Red × White = Red and White
9

11. 10

12. An allele of one gene masks the expression of
alleles of another gene and expresses its own
phenotype instead.
Gene that masks = epistatic gene
Gene that is masked = hypostatic gene
EPISTASIS
11

13. • Epistatic gene interaction Gene is classified as follow
on the basis manner by which concerned genes
influence the expression of each other
1. Supplementary gene action (9:3:4)
2. Complementary gene action (9:7)
3. Inhibitory gene action (13:3)
4. Duplicate gene interaction (15:1)
5. Masking gene action (12:3:1)
6. Polymeric gene action (9:6:1)
Classification of epistatic gene interaction
12

14. TYPES OF GENETIC
CROSSES
Monohybrid cross
cross involving a single trait
Dihybrid cross
cross involving two traits
13

15. 14

16. Dihybrid Cross
Traits: Seed shape and seed color
Alleles: R round
r wrinkled
Y yellow
y Green
RrYy × RrYy
RY Ry rY ry RY Ry rY ry
All possible gamete combinations
15

17. Dihybrid Cross
RRYY RRYy RrYY RrYy
RRYy RrYy RrYy Rryy
RrYY RrYy rrYY rrYy
RrYy Rryy rrYy rryy
RY
Ry
rY
ry
RY Ry rY ry
Round / Yellow: 9
Round / Green: 3
Wrinled / Yellow : 3
Wrinkel / Green : 1
9: 3: 3: 1 Phenotypic
ratio
1:2:1:2:4:2:1:2:1
Gynotypic ratio
16

18. Monogenic inheritance
Monogenic inheritance- Traits that develop because of the
influence of a single gene locus are monogenic.
Also called as mendelian traits
Shows discrete characteristics eg. Flower color etc.
17

19. Polygene- Several genes governing by the same character
Polygenic inheritance- Single characteristics controlled by
multiple genes.
Also called cumulative inheritance or Quantitative
inheritance or Multiple factor inheritance
Gene involved in quantitative inheritance is known as
Polygenes.
Each gene contribute equally
 Environmental factors may also effect
Does not follow Mendelian ratio
Polygenic Inheritance
18

20. History of polygenic inheritance
Joseph Gottlieb Koleuter- Father of polygenic inheritance
Herman Nilsson – Elhe and East – First to discover polygenic
inheritance in kernel color in wheat
Charles B. Davenport and Gertrude C. Devenport-Discover that
the inheritance of skin color in human occurs by polygenic
inheritance
J. B.Koleuter C.B.Davenport H Nilsson
19

21. “Trait or Character-Any property of an individual showing
heritable variation is known as character or trait”
It includes morphological, physiological. biochemical and
behavioral properties
Plant characters are of two types
1. Quantitative or polygenic - yield, days to flowering , days
to maturity, seed oil content, protein, content, etc.
2. Qualitative or oligogenic - colour of stem, flower, seed,
pollen, seed shape and their shapes
Polygenic Characters
20

22. Each contributing allele in the series of multiple genes
produces an equal effect.
Effects of each contributing allele are cumulative or
additive.
 There is no dominance, rather, there exist pairs of
contributing and non-contributing alleles.
 There is no epistasis (masking of the phenotypes)
among genes at different loci.
There is no linkage involved.
The environmental conditions have considerable effect
on the phenotypic expression of polygenes for the
quantitative traits.
CHARACTERISTICS OF MULTIPLE GENES
21

23. Skin color in human
Eye color
Cob length in maize
Human height
Kernel color in wheat
Example of Multiple Factor Hypothesis
22

24. Polygenic Traits Monogenic Traits
1. Governed by several genes Governed by few genes
2.Effect of each gene is not detectable. Effect of each gene is detectable
3. Usually governed by additive genes. Governed by non-additive genes
4. Variation is continuous. Variation is discontinuous
5. Separation into different classes is
not possible
Separation into different classes is
possible
. 6. Highly influenced by environmental
factors.
Little influenced by environmental
factors
7. Statistical analysis is based on mean,
variances and covariances.
Statistical analysis is based on frequend
ratios
23

25. Role of inheritance
Improve the efficiency, predictability and
effectiveness of breeding efforts
Its studies can uncover genetic mechanism of
several traits
To formulate an efficient breeding programme for
developing high yielding varieties
Helps in developing genetic poulations
24

26. It’s only real source of genetic variation and
explain how certain species can survive in a
changing environment
Helps in alteration of generation
Altering the architecture of plants
Developing desirable traits
25

27. How to workout –INHERITANCE
Chi- square statistical method is use for analysis
•Karl Pearson, an English mathematician, applied statistics to
biological problems of heredity and evolution.
•He developed the Chi- square test (commonly known as X2) of
statistical significance which is commonly used in Mendelian and
population genetics.
•This is a test of statistical significance which is used to test the
significance of difference between observed and expected
frequencies or ratios.
•The general formula of X2 is as follows: X2 = ∑(0-E)²/E
• where, ∑ = summation,O = observed frequencies and E = expected
frequencies.
26

28.  In genetics, X2 test is usually used for three main purposes viz.,
 To test the validity of various segregation ratios,
 For detection of linkage
 Study of gene frequencies in population genetics.
 Testing of Segregation Ratios
 The significance of deviation of an observed segregation ratio
from a hypothetical one can be easily tested with the help of X2
test.
 The X2 value is worked out and the calculated value of X2 is
compared with table value of X2 at 5 % level of significance and
n-1 degree of freedom, where n is the number of segregation
classes .
 If the calculated value of X2 is higher than table value, it is
considered significant and vice versa
Application of X2 Test
27

29. Classes of
segregation
Observed
frequencies (O)
Expected
frequencies (E)
X² Value
( O-E)2/E
Red flower 145 150 (145-150) 2 /150
White flower 55 50 (55-50) 2 /50
Total 200 200 (O-E) 2 /E
Table 1. Calculation of X 2 value for two classes segregation ratio
( hypothetic Ratio 3:1)
28

30. 29

31. Case study -1
INHERITANCE STUDY OF FLOWER COLOR IN CHICKPEA
( Cicer arietinum L.)
M. Tarikul Hasan and Anil Chandra Deb*(2013)
Department of Genetic Engineering and
Biotechnology, University of Rajshahi,
Bangladesh
Parents –
pink flower-BARI chola-1, BARI chola-2, BARI chola-3, BARI
chola-4, BARI chola-5, BARI chola-6 and BARI chola-7
White flower- BARI chola-8
Research Material
30
Objective- To study inheritance of
flower color on chickpea

32. Cross Type
Parent/
Generation
Flower
color
Expected
Ratio
No of Plant
X² P value
Cross
no.
Male Female Observed Expected
1 V-8 × V-1
BARI-8 White
BARI-1 Pink
F1 Pink
F2 Pink 3 73 84.75
White 1 40 28.25 6.52 0.0116
2 V-8 × V-2
BARI-8 White
BARI-2 Pink
F1 Pink
F2 Pink 3 112 108.75
White 1 33 36.25 0.39 0.5323
3 V-8 × V-3
BARI-8 White
BARI-3 Pink
F1 Pink
F2 Pink 3 83 92.25
White 1 40 30.75 3.71 0.0541
4 V-8 × V-4
BARI-8 White
BARI-4 Pink
F1 Pink
F2 Pink 3 169 180.75
White 1 72 60.25 3.06 0.0802
Table 2: Chi-square analysis of chickpea flower colour segregation.
….Continue 31

33. Cross Type
Parent/
Generation
Flower
color
Expected
Ratio
No of Plant
X²
P
value
Cross
no
Male Female Observed Expected
5 V-8 × V-5
BARI-8 White
BARI-5 Pink
F1 Pink
F2 Pink 3 88 90
White 1 32 30 0.18 0.6714
6 V-8 × V-6
BARI-8 White
BARI-6 Pink
F1 Pink
F2 Pink 3 183 201
White 1 85 67 6.45 0.0111
7 V-8 × V-7
BARI-8 White
BARI-7 Pink
F1 Pink
F2 Pink 3 121 127.5
White 1 49 42.5 1.33 0.2488
8 V-4 × V-8
BARI-4 Pink
BARI-8 White
F1 Pink
F2 Pink 3 110 117
White 1 46 39 1.68 0.1959
Heterogeneity (df 7) 7.45 0.3836
32

34. Inheritance of flower colour in Chickpea
(Cicer arientinum L.)
Case study -2
Namrata Burse1*, A. N. Patil2 and
S. B. Sakhare (2017)
Dr. Panjabrao Deshmukh Krishi
Vidhyapeeth, Akola, Maharashtra
White- Gulak, PKV Kabuli-4, AKG-2002-1K, Chanoli, BGD 1076
pink -JAKI9218
Research Material
33
Objective- To study the inheritance of flower color

35. 34

36. Cross: seed parent (genotype) X
pollen parents (genotype)
Flower
colour
No. of plant
Expected
ratio
Chi-square
Observed Expected
X² P-value
d.f.
Cross I: JAKI-9218 X Gulak
F1 (JAKI-9218 X Gulak) Pink
F2(JAKI-9218 X Gulak)
Pink 311 325.5 3 0.6022
White 123 108.5 1 1.8065 0.1206 1
F1 X JAKI-9218 (B1) Pink 67 - - - - -
F1 X Gulak (B2) Pink 27 33 1 0.9167 0.1758 1
White 39 33 1 0.9167
Cross II: JAKI-9218 X PKV
Kabuli-4
F1 (JAKI-9218 X PKV Kabuli-4) Pink
F2(JAKI-9218 X PKV Kabuli-4)
Pink 263 255 3 0.2206 0.3164 1
White 77 85 1 0.6618
F1 X JAKI-9218 (B1) Pink 53 - - - - -
F1 X PKV Kabuli-4 (B2) Pink 34 29 1 0.6983 0.1892 1
White 24 29 1 0.6983
Cross III: JAKI-9218 X AKG-
2002-1K
F1 ( JAKI-9218 X AKG-2002-1K) Pink - -
F2 (JAKI-9218 X AKG-2002-1K)
Pink 288 283.5 3 0.0564 0.6345 1
White 90 94.5 1 0.1693
F1 X JAKI-9218 (B1) Pink 50 - - - - -
F1 X AKG-2002-1K (B2)
Pink 30 27.5 1 0.1455 0.5896 1
White 25 27.5 1 0.1455
Table 3. Inheritance of flower colour in different crosses of chickpea
…continue 35

37. Cross: seed parent
(genotype) X pollen
parents (genotype)
Flower
colour
No. of plant
Expected
ratio
Chi-
square
Observed Expected X² P-value d.f.
Cross IV: JAKI-9218 X
Chanoli
F1 (JAKI-9218 X Chanoli) Pink
F2 (JAKI-9218 X Chanoli)
Pink 282 295.5 3 0.5719 0.1304 1
White 112 98.5 1 1.7157
F1 X JAKI-9218 (B1) Pink 63 - - - - -
F1 X Chanoli (B2)
Pink 30 34 1 0.3603 0.3958 1
White 38 34 1 0.3603
Cross V: JAKI-9218 X
BGD 1076
F1 ( JAKI-9218 X BGD
1076)
Pink
F2 (JAKI-9218 X BGD
1076)
Pink 252 246 3 0.123 0.483 1
White 76 82 1 0.3689
F1 X JAKI-9218 (B1) Pink 55 - - - - -
F1 X BGD 1076 (B2) Pink 30 26 1 0.4711 0.3318 1
36

38. Inheritance of Flower Color and Spininess in Safflower
(Carthamus tinctorius L.)
Case study-3
M. H. Pahlavani, A. F. Mirlohi, And G. Saeidi (2004)
Department of Agronomy and Plant Breeding,
Gorgan University of Agricultural Sciences,
Isfahan, Iran
37
Parental line Abbreviation
Leaf
spininess
Saffire P1 Spiny
IUTC129 P2 Spineless
IUTM12 P3 Spineless
IUTE1449 P4 Spineless
IUTH13 P5 Spiny
IUTK115 P6 Spineless
Research Material
Objective- To determine the
inheritance mode and the
number of genes controling
spininess .

39. No of observed plants
Cross Generation
No of
expected
plant
X² P
1
P1 X P2(F1) 41 0 — — —
P1 X P2(F2) 94 27 90.8:30.3 0.46 0.495
2
P1 X PX(F1) 38 0 — — —
P1 X PX(F2) 61 17 58.5:19.5 0.42 0.514
3
P1 X P4(F1) 28 0 — — —
P1 X P4(F2) 91 26 87.8:29.3 0.48 0.488
4
P2 X P5(F1) 26 0 — — —
P2 X P5(F2) 74 25 74.3:24.8 0.003 0.987
Sum of chi-square (df= 4) — — — 1.37 0.849
Pooled data 320 95
311.25:103.7
5
0.73 0.393
Heterogeneity chi-square (df = 3) — — — 0.64 0.887
Table 4. Classification of the plants in the F1 and F2 generations for spiny and
spineless leaf based on a ratio of 3:1
38

40. Case study -4
Inheritance of Flower Color and Leaf Shape of Chickpea
(Cicer arietinum L.)
D. Atanasova and M. Mihov (2006)
Dobroudja Agricultural Institute, Bulgaria
white flower- Dweley, Sanford, Stepnoi 1
violet flowers Obraztsov chiflik 1, Krasnokutskii 123 wild species Cicer reticulatum and
Cicer echinospermum –
simple leaves- Dweley and Sanford
compound (normal) leaves Obraztsov chiflik 1, Krasnokutskii 123, as well as the lines
FLIP 91-176c, FLIP 91-46c and FLIP 88-68c
Material
39
Objective- To study the flower color and leaf
shape of chickpea

41. Cross
No.
Hybrid combination
Number of plants in F2
Ratio χ2 Р
All
Violet
flowers
White
flowers
1
Obraztsov chiflik 1 х
Dwelley
23 18 5 3:1 0.13 90-50
2
Obraztsov chiflik 1 х
Sanford
21 16 5 3:1 0.01 99-90
3
Stepnoi 1 х
Obraztsov chiflik 1
26 16 10 3:1 2.51 20-10
4
Krasnokutskii 123 х
Sanford
11 10 1 3:1 1.48 50-20
5
Stepnoi 1 х C.
reticulatum
172 126 46 3:1 0.27 90-50
6
Stepnoi 1 х
C. echinospermum
168 139 29 3:1 5.36 5-1
7
Stepnoi 1 х
Krasnokutskii 123
57 50 7 3:1 4.92 5-1
Table 5. Inheritance of chickpea flower colour
40

42. Cross
No.
Hybrid combination
Number of plants in F2
Ratio χ2 Р
All
Normal
Leaves
Simple
Leaves
1
Obraztsov chiflik 1 х
Sanford
52 39 13 3:1 0 99
2
Krasnokutskii 123 х
Sanford
11 8 3 3:1 0.03 90
3 Sanford х FLIP 91-176c 32 25 7 3:1 0.17 90-50
4 Dwelley х FLIP 91-46c 10 7 3 3:1 0.13 90-50
5 Dwelley х FLIP 88-68c 21 13 8 3:1 1.9 20-10
6
Obraztsov chiflik1 х
Dwelley
24 17 7 3:1 0.23 90-50
Table 6. Inheritance of chickpea leaf shape
41

43. CONCLUSION
The trait viz., flower colour, spininess, leaf type, all of
these are monogenic in nature.
 Knowledge concerning the inheritance of qualitative
characters helps the plant breeder in increasing efficiency of
selection.
The genetic inheritance of different morphological traits is
essential for selection of superior and desirable transgressive
segregants for genetic improvement of the crop.
42

44. Thanks
The Nations’
Inheritance