This document summarizes the current status of hybrid rice research and development at IRRI. It discusses trends in hybrid rice adoption globally, with hybrid rice area growing by 2 million hectares from 2007 to 2011 outside of China. It identifies major challenges for hybrid rice in tropical regions like low yield advantages and heterosis. It outlines IRRI's hybrid rice research priorities and efforts to address challenges through developing new parental lines, disease resistance, and seed production technology. The document also summarizes recommendations from a hybrid rice symposium to increase yields, improve seed production, and strengthen public-private partnerships.

1. Current Status of Hybrid Rice
Research and Development
At IRRI
Fangming Xie
IRRI

2. Trend of Hybrid Rice Development
Public Private
China
Outside
China
China
Outside
China
R & D
Commercialization

3. Hybrid Rice Area in Major Rice Countries (000 ha) (2011)
Country Total Rice Hybrid Rice %
Bangladesh 12,000 700 5.83
India 44,100 2,000 4.54
Indonesia 13,201 650 3.91
Philippines 4,537 177.4 0.97
Myanmar 8,038 78.2 7.78
Vietnam 7,652 595 36.46
USA 1,204 439 14.5
L. America 5,047 70 1.39
Others 100
Subtotal 3,428
China 30,311 15,600 51.47

4. Changes of Hybrid Rice Area in Countries outside China
0
500
1000
1500
2000
25001000ha
2007
2011

5. Hybrid Rice is Growing Globally
2 million ha of hybrid rice added to production from 2007 to 2011
(10.2% increase), all were outside China
19.8
21.7
18.5
19.0
19.5
20.0
20.5
21.0
21.5
22.0
2007 2011
Millionha

6. 6.59
6.92
6.50
All (14) IRRI (3) Others (11)
Yield (t/ha) of Philippines Hybrids
Released in 2011
6.46% higher
IRRI Rice Hybrids in the Philippines
9
11
24
PhilRice/UPLB/Phil
SCAT
IRRI
Privatecompany
Hybrids Released in the
Philippines

7. Major Challenges of Hybrid Rice in the Tropics
• Low yield advantage (<1 t/ha), low heterosis (< 15%) & inconsistency
performance
o Genetic causes – no clear concept of heterotic groups
o Site / season specific hybrids - GxE interaction, rice ecosystems
o Inappropriate field management
• Low yield of seed production (1 - 2 t/ha) & high seed cost
o Low outcrossing females & poor seed production technology
o High cost of seed production
o Weather & Market fluctuation
• Unacceptable grain quality
o High Chalk, low head rice yield and unacceptable cooking quality
o Wide range of grain quality requirements/expectations
o Last words from rice millers for quality, price and purchase

8. Major Challenges of Hybrid Rice in the Tropics
• Lack of resistance to diseases and insects
o Various diseases / insects in the tropics
o Lack of appropriate resistance screening & breeding
o Poor education to farmer for Integrated Pest Management
• Poor seed quality
• Inappropriate maturity of hybrids
• Inconsistency of government policy (subsidy, seed production &
extension)
• Poor education to hybrid rice farmers
• Insufficiency of hybrid rice technical personnel

9. IRRI organized HRDC in 2008
• Develop effective collaborations between public and the private sectors
• Support research for parent and hybrid development
– Hybrid rice research (heterosis & other traits);
– Develop hybrids & parents and share w/ partners
• Provide information on the performance of hybrids & develop best
management practices
• Support information sharing, public awareness & capacity building
Objectives:

10. 22
24
30
27
29
31
17
20
25
31 31
36
0
5
10
15
20
25
30
35
40
2008 2009 2010 2011 2012 2013
HRDCMembership
Private Public
HRDC Members 2008 -2013

11. Hybrid Rice R&D Priorities at IRRI
Traits Trait Detail
Yield
Heterosis
• High yielding > 20% heterosis in the tropical
• Heterotic pools – concept and parental grouping
• Stable yielding over environments
Seed
Production
• High-yielding
• Stable sterility & high-outcrossing females
• Elite male parents
• Stable yielding
Resistance
&
Tolerance
• Diseases – BLB, Blast, Sheath Blight, False smut
• Insects - Stem Borer, BPH & WBPH;
• Drought, Salinity & Submergence
Quality
• Less chalk, non sticky
• Long grain or Medium grain with specific amylose
Maturity • 115 – 120 days, 120- 125 days
Others
• Wide adaption – parents & hybrids
• Plant architecture for high-yielding

12. • 15 ha/season for hybrid rice breeding
• 12,000 breeding lines & populations/year
• 2,700 new hybrids/year
Hybrid Rice Breeding

13. Germplasm shared with HRDC members & other
partners increased

14. Heterosis Level in Hybrid Rice
Indica x Japonica
Indica x Javanica
Japonica x Javanica
Indica x Indica
Japonica x Japonica
Genetic Divergence
HeterosisLevel

15. Cluster of IRRI Hybrid Rice Parents
168 lines based on 207 SSR markers 18 lines based on 207 SSR markers
Study for Heterotic Groups
• Parents clustered into 6 groups;
• B & R lines are genetically separated, but some “mixed” & different degrees of “closing”;
• 3 representatives selected from each 6 groups

16. P1 P2 P3 P4 P5 P6 P7 P8 P9 P10 P11 P12 P13 P14 P15 P16 P17 P18
P1 P X X X X X X X X X X X X X X X X X
P2 P X X X X X X X X X X X X X X X X
P3 P X X X X X X X X X X X X X X X
P4 P X X X X X X X X X X X X X X
P5 P X X X X X X X X X X X X X
P6 P X X X X X X X X X X X X
P7 P X X X X X X X X X X X
P8 P X X X X X X X X X X
P9 P =18 P X X X X X X X X X
P10 BxB = 66 P X X X X X X X X
P11 BxR = 72 P X X X X X X X
P12 RxR = 15 P X X X X X X
P13 P X X X X X
P14 P X X X X
P15 P X X X
P16 P X X
P17 P X
P18 P
G1
G2
G3
G4
G5
G6
G1 G2 G3 G4 G5 G6
Diallel Cross of 18 Parents
• Study heterosis between & within groups
• Total entries = 153 hybrids + 18 parents + 5 CKs
• Evaluated in 5 environments in 2 seasons: (1) 2010WS & 2011DS, Los Baños, Philippines,
(2) 2010WS and 2011DS, General Santos, Philippines, (3) 2011DS, Hyderabad, India

17. MEAN

19. Correlation between GD and Hybrid Yield MPH
Based on Individual Hybrids Based on Marker-GD Groups
R2 on Marker-based Groups >>> R2 on Individual Hybrids

20. Conclusions:
• IRRI-bred hybrid rice lines could be clustered into clearly separated B- and R-line groups,
with some minor “mixtures”;
• Some B-line groups (G1 and G4) are closer to R-lines than other B-line groups (G5 and
G6) – need to improve;
• Current IRRI B- and R-line groups suitable for hybrid development (BxR) w/o genetic
change for categories;
• Preferred choice for breeding heterotic hybrids within current germplasm:
o Females = G5 and G6;
o Males = G2 and G3;
• Limited value to use marker-based GD for predicting heterosis, but valuable for grouping
parents to increase opportunity of breeding heterotic hybrids.

21. Other Heterotic Groups
• Two-line hybrid rice currently in China?
• Other indica germplasm?
• NPT germplasm?
• Tropical and temperate japonica rice?
• Heterosis mechanism – heterotic gene blocks?

22. Studies of heterotic groups – Molecular markers + field evaluation
• 2nd Experiment: variety groups of IRRI and southern China indica (215)
• 3rd Experiment: variety groups of IRRI, China, some Asian and L. America countries (736,
major indica regions, genotyping = done, phenotyping = 2 locations / 1 season
China
IRRI
CIAT/L. America
Africa
China
IRRI

23. Development of high outcross female parents
Data: 05WS, 06DS,
AxB Paircross, 92
CMS lines
2013DS AxB Paircross
MEAN = 31.5%
2013DS AxB Yield Trial (3 Rep)
MEAN = 24.7%

24. Develop new CMS lines
with high outcrossing
IR58025A
New CMS A
New CMS BNew CMS A
High Seed Set of New CMS line

25. Other on-going Hybrid Rice R & D at IRRI
– Bacterial blight resistance
o Xa4, xa5, Xa7, xa13, Xa21, and Xa23
o IR68897B, IR58025B, IR 93559B, IR93560B, IR93561B
o Inoculums + Field screen + MAS
o BC3F1 (2012DS)
PCR product Bandings using Xa21 marker, a 1400 bp band (R) for IRBB21 & a 1200 bp band (S) for IR24
M: DNA size standard; Lane 1–7: IR24, IRBB66, IR93561B, IR93560B, IR93559B, IR58025B, IR68897B; Lanes
8–26: BC1F1’s

26. Other on-going Hybrid Rice R & D at IRRI
– Submergence tolerance
o Submergence + MAS
o IR68897B & SRT3R, and other B/R lines
o BC3F1 (2012DS)

27. Other on-going Hybrid Rice R & D at IRRI
– Drought tolerance: Transfer drought-tolerant QTLs
to hybrid parents using conventional and MAS
– Low chalk: Low chalk QTLs + MAS to improve
parents
– TGMS: Line selection and breeding
– Outcrossing: Conventional screening + traits from
wild rice
– SNP markers: Convert and confirm SNP markers for
Rf, sub-1, BLB, Blast, Amylose genes

28. JAAS-HRDC Hybrid Rice Training
Class Room
Field VisitSeed Plant Visit
Hands-on

30. 2012 DS HRDC MRYT at IRRI
Objectives:
1. Assist HRDC members in assessing the performance of hybrids
2. To enable HRDC members to generate reliable performance data
across a set of marketing locations

31. Recommendations from
the 6th International Hybrid Rice Symposium
Sept. 10-12, Hyderabad, India
• Increase hybrid yield and yield heterosis
– 2-line hybrid rice program outside China
– Rice heterotic group study
– Using marker technology
– Disease and insect resistances
• Improve seed production & seed production efficiency
– Refine seed production technology
– Find favorable locations to seed production
– Training for hybrid rice breeders and seed producers
– Reduce seed cost
• Strengthen public private partnership
• Policies favorable for hybrid rice production

32. Thanks & Questions