Current Status of Hybrid Rice

Research and Development

At IRRI

Fangming Xie IRRI

Trend of Hybrid Rice Development

Public Private

China Outside

China China

Outside

China

R & D

Commercialization

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

Changes of Hybrid Rice Area in Countries outside China

0

500

1000

1500

2000

25001000 h

a

2007

2011

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

Mil

lio

n h

a

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

PhilR

ice/U

PL

B/P

hil

SC

AT

IRR

I

Private

co

mpa

ny

Hybrids Released in the Philippines

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

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

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:

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

HR

DC

Mem

bers

hip

Private Public

HRDC Members 2008 -2013

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

• 15 ha/season for hybrid rice breeding

• 12,000 breeding lines & populations/year

• 2,700 new hybrids/year

Hybrid Rice Breeding

Germplasm shared with HRDC members & other

partners increased

Heterosis Level in Hybrid Rice

Indica x Japonica

Indica x Javanica

Japonica x Javanica

Indica x Indica

Japonica x Japonica

Genetic Divergence

He

tero

sis

Leve

l

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

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

MEAN

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

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.

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?

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

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%

Develop new CMS lines

with high outcrossing

IR58025A

New CMS A

New CMS B New CMS A

High Seed Set of New CMS line

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

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)

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

JAAS-HRDC Hybrid Rice Training

Class Room

Field Visit Seed Plant Visit

Hands-on

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

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

Thanks & Questions