Bajra, Maize, Rice hybrids using male sterility

1. An Assignment On
General Scenario Of Hybrid Seed
SUBMITTED TO:-
Dr. A. K. Sharma
SUBMITTED BY:-
Navreet Kaur Rai
(M. Sc. (Ag.) Previous yr.)

2. Outline
• Introduction
• History of Hybrids
• Development of Hybrid
• Hybrid seed produvtion in Bajra
• Hybrid seed production in Maize
• Hybrid seed production in Rice
• Merits of Hybrids
• Achievements of Hybrid Varieties

3. Introduction
• Hybrid varieties: Hybrid varieties are the first generation (F1)
from crosses between two purelines, inbreds, open pollinated
varieties, clones or other populations that are genetically dissimilar.
• Pureline: It is the progeny of single self – fertilized homozygous
plant.
• Inbred line: It is a nearly homozygous line obtained by continues
inbreeding in a cross-pollinated crop followed by selection.
• Single cross: When two inbred lines or pure lines are crossed to
produce the F1 hybrid, it is known as single cross.

4. Contd…
• Double cross: When two single crosses are crossed the resulting
hybrid population is known as double cross.
• Three-way cross: It is a cross between aa single cross and an
inbred to give hybrid population.
• Top cross: When an inbred is crossed with an open pollinated
variety, it is known as an inbred variety cross or a top cross.
• Polycross: It is the progeny of a line produced through random
pollination by a number of selected lines.
• Varietal cross: When two open pollinated varieties are mated it
is known as varietal cross or population cross.

5. History of Hybrids :-
• Hybrids were first commercially exploited in Maize.
• In 1908, Shull suggested a method for producing single cross hybrids
in Maize.
• The double cross scheme was proposed by Jones in 1918.
• The first double cross maize hybrid was produced at the Connecticut
Agricultural Experimental Station and grown in Connecticut in 1921
and was named as Burr Learning Hybrid.
• The concept of topcross hybrids for preliminary screening of inbreds
was proposed by Davis in 1927.

6. Contd…
• In india, intensive research for the development of hybrid maize
began in 1952 when Coordinated Maize Improvement Project
began in collaboration with the Rockefeller Foundation.
• In 1961, Four hybrids of Maize were released; Ganga 1, Ganga 101,
Ranjit and Deccan.
• The first hybrid variety of Jowar, CSH 1, was releases in 1964.
• First hybrid In Bajra was HB1.

7. National Scenario -
• BAJRA
– India is the largest producer of this crop both in terms of area
(7.12mha) and production (8.06 MT) , with an average productivity of
1132 kg per ha.
– The hybrids are cultivated on 70% of the total pearlmillet area,
leading to 124% increase in productivity since 1986-90.
• MAIZE
– Maize is the third most important food crop in India after Rice and
Wheat.

8. – Area under hybrid seeds in 2010-11 is estimated to be 60% of total
area under Maize cultivation.
– Productivity in India is - 2.43 t per ha.
• RICE-
– Rice is staple food of more than 60% of the world population.
– In India, area under Rice cultivation is 44.6 mha and production is
about 3 tonn per ha.
– Around 3+ million hactares area is under Hybrid Rice cultivation in
India in 2016 which is around 7% of the total Rice cropped area.

9. Development Of Hybrid
• Breeding for hybrids involves three steps:
1. Development of Inbred lines
2. Evaluation of Inbred lines-
a. Phenotypic evaluation
b. Top Cross Test
c. Single Cross Evaluation
d. Prediction of the performance of Double
Cross Hybrids
3. Commercial utilization of the crosses for seed production

10. Hybrid seed
production in-
Bajra

11. Classification –
– BOTANICAL NAME: Pennisetum glaucum
– FAMILY: Poaceae (Gramineae)
– ORIGIN: West Africa
– CHROMOSOME NO. : 2n=2x=14
MODE OF POLLINATION-
– Bajra is predominantly Protogynous and Cross-pollinated crop.
– Wind is major pollinator.

12. Why hybrid bajra?
• Enhancement of grain and fodder yield.
• Improvement of quality.
• Increase resistance to pests and diseases.
• Increase wider adaptability.
• Varieties for new season.
• Low cost of production.
• Tolerant to biotic and abiotic stresses.
• Uniformity and high productivity.

13. Breeding Technique For Hybrid Seed Production
-
• The hybrid seed in Bajra is produced by utilizing CYTOPLASMIC GENETIC MALE
STERILITY system (CGMS).
• The cytoplasmic male sterile source used in Bajra is Tift-23A identified by G. W. Burton
at Tifton Georgia, USA.
• Lines involved – A, B and R-lines
• A-line: It is the male sterile parent line.
- Stable sterility.
- Well developed floral traits for outcrossing.
- Easily, wide-spectrum and strongly to be restored.
• B-line: The fertile-counterpart of A-line and is used to maintain A-line (Maintainer line).
- Well-developed floral traits with large pollen load.

14. Contd…
• R-line: Strong restore ability (carries genes for fertility restoration).
- Good combining ability.
- Taller than A- line.
- Large pollen load, normal flowering traits and timing.
• CGMS system is based upon-
1. A cytoplasm that produce male-sterility.
2. A gene that restores fertility.
• Steps involved in CGMS system in Bajra-
A. Maintenance of A and B-line.
B. Maintenance of R-line.
C. Commercial hybrid seed production (A x R).

15. SOME Male sterile lines in bajra-
• Coastal Plain Experiment Station, Tifton, Georgia, USA - Tift 23A,
Tift 23DA, Tift 18A.
• PAU ,Ludhiana, India - Pb 111A, Pb 101A, Pb 201-Pb 215A.
• IARI, New Delhi, India - 5141 A, 5054 A, 3893 A, 3383 A, 5071 A,
5540 A, 5184 A.
• ICRISAT ,India - 81A, 833A, 834A, 841A, 842A, 843A, 851A,
852A
• MAHYCO Ltd. ,India - MS1, MS2, MS4-MS9, MS11-MS14

16. Commercial Hybrid Seed
Production-
• Nuclear seed-
»By Ear to Row method
• Breeder seed-
»A X B line
• Foundation seed-
»A X B line
• Certified seed-
»A X R line ( To produce hybrid)

17. Identification Of Potential Hybrid Parents (A-, B-
and R- lines) :-
• Potential male and female parents for hybrid seed production are
identified by crossing male-fertile plants (inbreds, varieties,
germlasm, breeding stocks in advanced generations, etc.) to male-
sterile line ( A-line) and observing their corresponding hybrids in
small plots of an observation nursery.
MALE FERTILE X MALE STERILE
F1
• A few plants of each cross are subjected to a Bagging Test, i.e.,
covering a few panicles with paper bags before anthesis, and
observing seed-set under the bag after a few weeks.

18. Contd...
• A normal bisexual fertile panicle would exhibit nearly 100% seed set
whereas in crosses with A-lines, the following 3 types of hybrids are
encountered.
1. HYBRIDS HAVE NO SEED-SET :- i.e., male sterility is maintained in these
hybrids. The corresponding pollen parent is classified as a non-
restorer/maintainer or B-line ans as a potential new A-line.
2. HYBRIDS EXHIBITING COMPLETE SEED-SET UNDER THE BAG :- i.e.,
male fertility has been completely restored in these hybrids. The
corresponding pollen parent is classified as a potential male-
parent/restorer line or R-line and could be useful in producing hybrids.

19. Contd...
3. HYBRIDS EXHIBITING PARTIAL SEED SET UNDER THE BAG :- Such hybrids
and their male parents are rejected for further studies because
experience shows that it is difficult to extract stable R-lines or B-lines
from such parents.

21. A. Maintenance of A-line (Male Sterile Line) and
B-line (Foundation seeds) :-
• Grow A-line and its corresponding maintainer, B-line together in an isolated
plot.
• The usual planting ratio is-4:2 OR 1:1 (4 lines of A-line and 2 lines of B-line) with
4-6 borders of B-line around the field.
• Isolation requirement – 1000m from other bajra fields.
• Some Cultural Practices –
Seed rate – A-line: 1.5kgs/ha (Drilling)
- 600-650gms (Transplanting)
B-line: 0.75kgs/ha (Drilling)
- 200-300gms (Transplanting)

22. Field layout

23. Contd…
Main field preparation - Formed into Rigdes and Furrows
Spacing- RxR= 70-90cms ; PxP= 20-25cms
• Follow the recommended package of practices as that of normal
cultivation.
• Pollen produced by B-line fertilizes the male-sterile plants (A) and
seed produced thus, gives rise to the A-line again.
• Roguing shuld be done frequently to produce high quality seed.
• Harvesting- Harvest male rows first and then harvest female rows
to avoid mechanical mixture.
• Seed yeild- 3-4 q/ha.

24. B. Maintenance of R-line :-
• It is produced in an isolated field.
• In Bajra, R-line could be either an inbred line or open
pollinated variety which can be multiplied as variety.
• Isolation distance – 1000m
• Roguing is must for eradication of off-types.
• Purity of parental seed is very important because it affects the
quality of hybrid seed that is generated.

25. C. Commercial Hybrid Seed Production :-
• The hybrid seed is produced by crossing male sterile line (A-line)
with the restore line in an isolated field.
• Planting Ratio: 4:2 or 6:2 ( 4 or 6 lines of A-line and 2-lines of R-line)
• Isolation requirement : 200m
• Roguing is done timely.
• All other practices are same as that of maintenance of male sterile
line.
• Synchronization of flowering is must and if there is any difference
in flowering then it can be adjusted by cultural practices.

26. Steps Of Synchronisation Of Flowering:
Withholding irrigation
Application of DAP 1%
Staggered sowing
JERKING – It is done 20-25 days after transplanting or 30-40 days after
direct sowing. The early formed earheads of the first tillers are pulled out
or removed which will result in uniform flowering of all the tillers.
• The synchronisation problem is less in Bajra due to-
• Tillering habit
• Supply of continuous pollen
• Flight capacity of pollen
• Pollen viability and stigma receptivity are longer

28. A & R

29. Some Commercial Bajra Hybrids -

33. Hybrid Seed Production In-
Maize

34. Classification-
– BOTANICAL NAME: Zea mays
– FAMILY: Poaceae (Gramineae)
– ORIGIN: Mexico
– CHROMOSOME NO. : 2n=20
MODE OF POLLINATION –
– Maize is a Cross-pollinated and
Protandrous species.

35. Male part-
Tassels
FEMALE
PART- SILK

36. Characteristics Of Hybrid
Maize :-
• It is uniform in appearance.
• It has vigour.
• It is high yielding.
• A particular hybrid can be selected for specific pest and
disease resistance or draught tolerance.

37. Hybrid Seed ProductionHybrid seed of maize may gwnerally be produced from following different cross
combinations –
• Single cross:- (AxB)
Eg.:- DMH-2(Cl-4 x KDM-10) ,NAH-2049(147-F2#89 x MAI-105)
• Double corss:- (AxB) x(CxD)
Eg.:- Deccan(CM 104 x CM 105) X ( CM 202 x CM 201),
Ganga-1( CM 101 x CM 102) X ( CM 200 x CM 202)
• Three-way cross:- (AxB) x C
Eg.:- Ganga-5(CM 202 x CM 111) X CM 500
• Double top cross:- (AxB) x Composite
Eg.:- Ganga Safed, Histarch, Ganga-4

38. Single-Cross Hybrid Production-
• Foundation seed production.
• Cross between two unrelated inbred lines.
• Planting Ratio: 4:2 Seed Rate: Female- 10kgs/ha
Male- 5kgs/ha
• Detasselling – When CMS line is not used the seed parent has to be detasselled so that
it will be fertilized by the pollen from the male parent. Removal of the tassel from the
female parent before shedding pollen is called detasselling.
• Non-synchronization of Flowering:-
-Good seed set in seed parent can be achieved by chronological adjustment of
pollen shedding and silking respectively.
-Prolongation of effective flowering period, planting design, efficient alteration of
rows planting ratio, staggered planting are some of measures which are effectively used
to ensure maximum synchronization and good seed set.

41. Advantages of Single Cross Hybrids-
• High acceptability among the farmers and requires only two parents.
• Tolerant to biotic and abiotic stresses.
• Quick and higher percentage of germination.
• Faster growth and more uniform.
• Single cross hybrids are homogeneous whereas all other kinds of
hybrids areheterogeneous.
• Less yield reduction under nutrient stress condition.
• Low cost of production.
• Food,income and nutritional security for resource-poor farm families.

42. Double-Cross Hybrid Production-
• Double Cross Hybrid are produced by crossing 2 different
single crosses.
• It is commercial seed production method (Certified Seeds).
• Planting Ratio: 6:2
• Isolation req. – 200m
• Detasseling, rouging and all other practices are must.
ADVANTAGES OF DOUBLE-CROSS HYBRIDS-
• Double cross hybrid seed production is a practical and
economical way of producing adequate seeds for farmers
because both parents are hybrids.

43. • They are also more variable than single or 3-way crosses thus
allowing breeders to bring more different desirable
characteristics together into one hybrids.
• Double cross plants have a longer pollination period.
DISADVANTAGE OF DOUBLE-CROSS HYBRIBS-
• The fields of double cross hybrids donot possess the “eye appeal”
of single cross hybrids because the plants and ears tend to be
more variable and they may be more difficult to obtain a high
level of disease and insect resistance compared to single crosses.

44. • Three parents are involved in three-way cross hybrid formation.
• The female of a three-way hybrid is a single-cross hybrid (AXB),
while the male is an inbred line (C).
• Three-way hybrid seed is produced on a single-cross plants so that
yield and quality may be equal, or nearly so, to double-cross
hybrid seed.
• Three way crosses are more variable than single crosses and less
variable than double crosses.

45. Stages In Commercial Hybrid Seed
Production-
• PRODUCTION OF THE BREEDER:-
–The breeder selects and produces the seed for the inbred lines.
–Breeder seed is used for foundation or basic seed production.
• PRODUCTION OF FOUNDATION OR BASIC SEED:-
–Foundation seed is the first multiplication of the breeder
seed(inbred lines).
–This is also the stage in which the single cross hybrid will be
produced for the three-way or double cross hybrids.
–Enough seed of the parents should be produced in order to
produce the hybrid seed.

46. • PRODUCTION OF CERTIFIED SEED:-
– It is the last stage in seed multiplication.
–Seed companies usually contract approved and capable farmers to
plant the foundation seed to ensure:
 Genetic purity
 To produce enough seed for the farmers.
–The seed fields are constantly checked for:
 isolation,
 off-types and purity.
–Harvested seed is verified for defects, adequate germination rate
and freedom from pests and diseases.

47. Hybrid Seed Production
In-
Rice

48. Classification -
–BOTANICAL NAME: Oryza sativa
–FAMILY: Poaceae (Gramineae)
–ORIGIN: South-east Asia
–CHROMOSOME NO. : 2n= 24
MODE OF POLLINATION -
–Rice is a self pollinated crop.

49. Hybrid Rice -
• Prof. Yuan Long Ping is the father of
hybrid rice in China.
• In general, the hybrid rice gives 1.0
ton more yield than the best variety
available.
• At present many rice hybrids have
been developed in the country from
different states.
• The first rice hybrid have been
developed in India by ANGRAU.

50. Benefits-
• Improvement in yield.
• More tillers will produced.
• Seed requirement reduced.
• Decrease in environmental pollution through lowered use of
chemical fertilizers and agrochemicals.
• Substantial water savings.

51. Production of Hybrid Rice-
• Three techniques are generally used-
1. Two –line system : Involves the use of photoperiod or
temperature sensitive genetic male sterile system.
2. Three –line system : by utilizing CGMS system.
Source of male sterile cytoplasm used in wild abortive.
3. By using Chemical Emasculants : Chemicals are used
to kills or sterilise the male gamete.
• However, 3-line system is successful.

52. • It involves following steps-
1. Maintenance of parental lines - Foundation seed
2. Commercial hybrid seed production - Certified seed
• The 3-line system involves 3 lines- A, B and R-line
–A-line: It is Male Sterile Line.
–B-line: Maintainer Line
–R-line: Restorer Line

54. Maintenance of A-line or Hybrid Seed
Production -
• Transplanting young seedlings less than 14 days old.
• Careful transplanting of single seedlings per hill.
• Transplanting in square pattern, preferable with 25x25 cm spacing.
• Planting Ratio : 2:8, 2:6 or 3:8
• Isolation requirement : Foundation seed- 200m
Certified seed- 100m
• Spacing : A-line : 15x15 cm
B-line : 20x15 or 30x15 cm
R-line : 20x15 or 30x15 cm

55. Contd…
• Emphasis on organic fertilizers.
• Weeding should be done to increase aeration as well as weed
control.
• Alternate wetting and drying upto the panicle initiation stage
through irrigation by way of a thin film of standing water.
• Some Rice Hybrids :- APRH-1, APRH -2, MGR-1, Pusa RH- 10, etc.

56. Methods Of Increasing Out–Crossing Rate-
• Paddy is highly self-pollinated crop and the extent to natural cross-
pollinated is very less.
• Hence to increase the out crossing rate certain methods should be
followed like-
1. FLAG LEAF CLIPPING : Flag leaves are taller than panicles and are
the main obstacles for pollen dispersal and cross-pollination.
–Hence, flag leaf should be removed one or two days before heading.
–The flag leaf should be cut to half or 2/3 of the blade from the tip.

57. 2. SPRAYING OF GA3: Application of GA3 increases the
internode length and the panicles will be fully exerted from
the flag leaves.
3. ROPE PULLING: Rope pulling should be done at peak
flowering time, which helps in shaking of male plants and
dispersal of pollen grains.

58. Some Rice Hybrids -

59. Basmati -
• Basmati is a variety of long, slender-grained aromartic rice
which is traditionally from the Indian subcontinenet.
• Basmati rice has a typical flavour caused by the aroma
compound 2-acetyl-1-pyrroline.
• Basmati grains contain about 0.09 ppm of this aromatic
chemical compound naturally.
• Basmati rice is known as king of rice and is priced for its
characteristic long-grain, subtle aroma and delicious
taste.

61. Merits of hybrid varieties -
• Hybrid varieties expliot both GCA and SCA components of heterosis.
• The produce from particularly single cross variety is more uniform
as compared to that from open pollinated.
• They can be produced both in cross and self-pollinated crop species.
• Hybrid are maintained in the form of their parental inbreds, which
are grown in isolation and subjected to selfing or sib-mating.
• In many self-pollinated crops, hybrid varieties yield 25-30% more
than the pureline varieties.

62. Achievements of Hybrid Varieties-
• The hybrid varieties have been commercially exploited in mostly of the
cross pollinated species, especially in Maize.
• Hybrid varieties have been successful in some self-pollinated crop as
like Cotton in India.
• Tomato, Chillies, Rice in China and India & Wheat in U. S. A.
• In India, hybrid varieties have been released for commercial
cultivation in 12 field crops.
• The first hybrid variety in Maize was released in 1961.
• In Bajra, HB1 hybrid variety released in 1965 PAU, Ludhiana.
• First hybrid variety of Cotton was H4; it was developed by Gujarat
Agricultural University and released for commercial cultivation in 1970.

64. Thank You