The document discusses hybrid rice production methods, primarily focusing on the CGMS system and the multiple approaches used for seed production, including the use of chemical emasculants. It highlights key practices for maintaining parental lines, planting ratios, field inspections, and techniques to improve cross-pollination. Additionally, it outlines cultural practices and precautions during harvesting and threshing to ensure high seed yield.

1. SUBMITTED TO:
Dr. UMESH KUMAR sir
Assistant Professor
Dept of Genetics and Plant Breeding
SUBMITTED BY:
NAA/18-17
NAA/18-32
NAA/18-53

2.  Prof. Yaun Long Ping is the father of hybrid rice in
China
 Hybrid rice gives 1.0 ton more yield than the best
variety available
 The first rice hybrid has been developed in the country
by ANGRAU i.e., APHR-1 and APHR-2

3.  Hybrid rice can be produced by 3 different methods
1) Three line system
2) Two-line system
3) By using chemical emasculants

4.  By using CGMS system. In this method, three
different lines are used i.e.,
1) A-line or male sterile line
2) B-line or maintainer line
3) R-line or restorer line

6.  This method hybrid rice seed production involves the
use of both PGMS or TGMS system
 Any normal line can used as restorer line
 Maintainer line is absent

8.  Chemicals which kill or sterilize the male gametes
with no effect on female gametes can be used to
emasculate female parental line
 In China: these emasculants commonly used in hybrid
seed of rice
 In India: not used for Hybrid seed of rice but used in
academic studies
 Chemical used as potent gametocides are ethrel,
maleic hydrazide etc

9.  Hybrid rice seed is produced by CGMS system
 Involves two steps:
Maintenance of parental lines (A-line; B-line and R-
line)
Commercial hybrid seed production (A*R)

10.  Land Requirement: The same crop should not be grown on the
same piece of land for the last one season
 Isolation Requirement: The hybrid paddy fields
Certified seed – 200 meters
Foundation seed – 100 meters
 Brief Cultural Practices: Follow all recommended package of
practices and take necessary prophylactic measures to raise a
good crop
 Planting Ratio: The planting ratio of male and female are 2:6; 2:8
or 3:8

11.  Number of Field Inspections: Minimum 4 field
inspections must be held
1st field inspection – before flowering
2nd and 3rd field inspection – during flowering stage
4th field inspection – before harvesting
 Roughing: Removal of off types and plants which are
infected with stem borer and diseased plants like
paddy bunt

12.  Paddy is highly self pollinated crop and extent of
natural cross pollination is very less,
 To increase out crossing certain methods should be
followed:
1) Flag Leaf Clipping
2) GA3 Application
3) Rope Pulling

14.  Flag leaves are taller than panicles and are the main
obstacles for pollen dispersal and cross pollination
 Hence the flag leaves should be removed so as to
improve cross pollination and seed set
 The flag leaves should be clipped one or two days
before heading so that it enhances uniform pollen
movement and wide dispersal of pollen grains to give
higher seed set
 First cut the flag leaf of the main tiller at the flag leaf
joint and use it as a guide in clipping the remaining
plants

15.  The flag leaves should be cut to half or 2/3 of the blade
from tip
 Do not clip the flag leaves in plants which are infected
with bacterial leaf blight or sheath blight
 The cut leaves can infect other plants or contaminating
tools used for flag leaf clipping can spread infection.
 The infected plants may be clipped after completing
the clipping of healthy leaves

16. Application of GA3
 Increases the internodes length
 Increases the duration of floret opening and stigma
receptivity
Spraying of GA3 should be done twice
 1st – 15-20% of the plants started heading with 40% of
chemicals
 2nd – 50% flowering with 60% of chemicals

18.  Rope pulling should be done during the peak
flowering time, which helps in shaking of the male
plants and dispersal of pollen grains
 Rope pulling should be done daily during peak
flowering stage at 8:30 AM and it should be repeated
3-4 times a day at an interval of half an hour

19.  Harvest the male row first and remove them from
fields so as to avoid mechanical mixture.
 Then harvest female rows
 Precautions should be taken while harvesting, not mix
male and female plants
 Threshing should be done on clean floor and should
be winnowed before storage

20.  Depending on the management practices adopted and
the potentiality of the parental line in the seed yield
may be in the range of 0.5-1.5 t/ha.

21. THANK YOU