This document discusses seed production methods for rice varieties and hybrids. It provides information on rice cultivation in India, the role of ICAR in releasing new varieties, and the different systems used for hybrid seed production. The key points are: - Rice is a staple food for 50% of the world's population and India is the second largest producer. ICAR has released over 1400 rice varieties and hybrids through multi-location testing. - Hybrid seed production uses a three-line system with A, B, and R lines, where the A line is male sterile. The R line is used to restore fertility in the F1 hybrid. Proper synchronization of flowering between the lines is important.

1. Seed production certified and foundation
seed in paddy
Prepared by G. shiva kumar Asst prof GPB
School of Agriculture , Anurag University.

2. Rice/paddy (oryza sativa L 2n=24)
INTRODUCTION
Rice is staple food for about 50% of world population for Asian continent
In India rice is grown in 44.15 million hectares and is the second largest producer of rice in the world with production of 116.47
million tons (2018-19).
Indian Council of Agricultural Research (ICAR) established All India Coordinated Research Projects in different crops to
conduct multi-location tests and to assess their performance in different regions or locations for release of varieties and hybrids.
For rice, ICAR-Indian Institute of Rice Research (formerly Directorate of Rice Research), Hyderabad is the nodal institute for
carrying out AICRIP related work.
• Present status of rice
ICAR-Indian Institute of Rice Research (ICAR-IIRR) has adopted a unique model to facilitate joint programme planning and
implementation of multi-location testing along with exchange of breeding and germplasm material. During the past 53 years
(1966 to 2019), a total of 28837 elite lines developed by different cooperating centres were tested in multi location trials across
the country under the umbrella of AICRIP. Till date, AICRIP was instrumental in release of 1410 varieties including 123 hybrids.
A total of 301 varieties including 77 hybrids released by Central Sub-Committee on Crop Standards, Notification and Release of
varieties (CSCS & NRV) and 1109 varieties including 46 hybrids released through state variety release committees (SVRC)
(Figure 1).

3. FIG 1 RICE VARIETIES AND HYBRIDS RELEASED IN INDIA.

4. • Among the 123 hybrids released, 33 are from public sector including three hybrids from ICAR-IIRR (DRRH 1, DRRH 2 and DRRH 3) and 90
from private seed companies. Interestingly, Pusa RH 10 is the only public sector (ICAR-IARI, New Delhi) released basmati hybrid. ICAR-
Indian Institute of Rice Research is instrumental in release of India’s first zinc bio-fortified variety (DRR Dhan 45) and a MAS bred variety
with bacterial blight resistance (Improved Samba Mahsuri). In addition to these, varieties with different traits have been developed and
released from different research organizations across India are listed in Table 1.

5. FLORAL BIOLOGY OF PADDY
PLUMOSE
STIGMA
MONOCARPELLARY
SUPERIOR OVARY

8. CRITICAL GROWTH STAGES OF PADDY

9. Panicle initiation
Boot leaf stage is completely out
Panicle emerges 4-5 days
Flower opening (6-8 days for complete flowering)
Flower opens in between 7-10 am
# the dehiscence of anther is independent of spikelet opening. The dehiscence may take place before opening opening or after
opening of flower
*stigma receptivity is for 3 days
*pollen grains are viable for 10 min under field conditions
• Seed multiplication ratio is 1:80 varieties and 1:100 Hybrids
*flower opening start from tip of primary and secondary branches and proceeds downward

10. Methods of seed production
OPV’S
Seeds of OPV are planted in isolation they are allowed to set and later multiplied in different stages nucleus seeds are
preserved by ear to row method.
Hybrids
the tool involved in hybrid seed production is known as cytoplasmic genetic male sterility system (3 line system)
Aline X B line produces A - line (*A&B lines are Isogenic line A X B is needed for Multiplication of Aline as its
sterile hermaphrodite flower)
A line
*but B-line is produced by selfing (B line x B line)
R line
x
New Hybrid

11. • A line B Line
R Line
Source
OsMYB80_Regulates_A
nther_Development_an
d_Pollen_Fertility_
Induced male sterility
by mutation

12. R line is produced in isolation from A and B line
Difference between OPVS and Hybrids
Seasons:-
Hybrid seed yield is higher in Rabi (January-April) seasons compared to Kharif (may-Aug)
Seeding of parental lines should be done in such a way that flowering coincides with
RH% 70-80%
Temp – 25-30^0
Land requirement
Free from voluntary plants
Isolated from same crop
Isolation
3 m for varieties in both foundation and certified class of seed
For hybrid the isolation requirement is of 200 and 100 m @foundation and certified seed Respectively
When space isolation is not possible time isolation of 21 days or barrier isolation with polythene sheets of 2 m
height

17. Upgrading seed
paddy seeds are upgraded based on seed wt before sowing by density
grading using common salt solution , 1.5 kg of salt dissolved in 10 liters of
water, heavy seeds are collected and lite seeds are removed and those
heavy seed should again rinsed by fresh water.
Pre sowing seed hardening treatment
Soak seeds in 1% KCL for 10hrs in 1:1 ratio then the seeds are dried back to
original moisture content (11-12%) and treated with captan 2g/ kg
To raise wet nursery rice seeds should be pre-germinated as seeds will not
germinate in water logged anerobic condition since oxygen is very essential
for germination
Seed soaking should be done in gunny bags and stored for 24 hours in dark
then plumule can be observed as white dot.

18. Dormancy breaking.
Seeds may be soaked in HNO3 (240 ml in 45 lit of water ) in 1:1 ratio for
12-16 hours
Nursery management
for hybrid seed production female and male nurserys should be raised separately sparse sowing in
nursery @1kg /cent
Application of DAP @2 kg /cent
#basal application of DAP recommended when seedlings are to be pulled out in 20-25 days after
sowing
• Where root snaping is a problem DAP is applied 1KG per cent 10 Days after sowing
Advantages of Phosphorous application to Nursery
I. Seedlings absorp and store phosphrous and utilize even at later stages of crop growth
II. 30% recommended phosphorous as per soil test is applied to main field
III.Application of phosphrous is very echonomical such as proper synchronization of flowering b/w
male and female parent in Hybrid seed production
Root soak treatment
Prepare 100 ml of chlorphyripos and 2.5 kg urea dissolved 50 lts of water for 20 min

19. PULLING OUT SEEDLINGs
18-22 days for SHORT
25-30 days for medium
35-40 days for long duration varieties
Main field preparation
A:R or A:B line is planted in 2:8 ratio 8 lines are A lines and 2 line are B/R lines
*female should be sowed as single
*male R/B should be 2 or 3 seedlings per hill
fertilizers 150:60:60 P is added at Last puddling N and K applied at 3 splits such as basal, active tillering, P.I stage
Hybrid rice seed production
How to formulate the ms system in Rice
CGMS is Most common and others are
1. one line breeding system
2. two line breeding system
3. Three line system
Commonly known as CMS
a) Emasculation and dusting method
b) Use of GMS (TGMS, PGMS)
c) Use of gametocides
Malic hydrazide
Ethrel
RH 531
Zms
SMS
A, B, R lines

20. Characters of CGMS
should have complete pollen sterility to avoid S.P and sterility should be stable in any environment.
Should have Fair GCA
good agronomic potential
Before flowering leaf clipping should be done
Flowering and synchronization
Male flowering vary with 6-8 days
Female line vary with 8-10 days
So synchronization can be achieved by following techniques
Staggered sowing
Urea application

21. Withhold of irrigation
GA3 application
Rope pulling/Rod Driving/Bamboo Beating
https://www.youtube.com/shorts/KitD7OZ6rLc
https://www.youtube.com/shorts/0cy393PDINo
rouging
Harvesting panicle turns into straw yellow colour
Plants harvested with intact panicle
Male harvested first and clean all male lines first and later check field to be male line free and start cutting
female line to avoid admixtures