Improvement of Rainfed Lowland Rice Variety for Cooking Quality Traits using MAS

Sureeporn KatengamUraiwan Kotchasatit

UBONRATCHATHANI, THAILAND

Background Rice production in NE of Thailand Area of production ranging from

drought-prone lands to flooding area

Abiotic stresses related with unpredictable rainfall pattern are main problems

State of problem Abiotic stresses associated with

unpredictable rainfall pattern are main problems for rice production in NE of Thailand.

Elite cultivars resistance to drought are required.

State of problem (cont.) KDML105, an aromatic rice with good

cooking quality, is widely grown in NE, however, its production is dominating constraint with the drought problem.

Drought tolerance is a complex traits since this trait is governed by many QTLs locating in many chromosome (ch1, ch2, ch3, ch4, ch7, ch8,and ch9).

Therefore, improvement KDML105 for drought resistance is not an easy tasks.

State of problem (cont.) In the opposite way, improving of well

adapted variety to drought prone areas for other quality traits such as cooking quality is worth to reconsider.

Cooking quality trait is determined by three characters specifying the physical properties of starch in the endosperm:

Amylose content (AC) Gel consistency (GC) Gelatinization temperature (GT)

Objectives Marker-assisted backcross breeding is

aimed at improving well drought adapted variety to rainfed lowland area of NE of Thailand for cooking quality traits utilizing tightly linked DNA markers.

The major QTL controlling AC, GC, and GT are located on Ch.6. DNA marker of flanking markers closely linked to this major QTL controlling quality traits will be carried out for MAS.

Plant materials Donor parent:

KDML105 low AC (~16-17%): major QTL on ch6 (at Wx

gene ) low GT: major QTL on ch6 medium GC: major QTL on ch6 (at Wx gene )

Recipient parent: IR57514-drought

Breeding scheme:

Chr.6 Chr.11

Map location of QTLs controlling cooking quality traits

Genetic map (Azu / IR64 )

# Markers Traits ChromKDML 105 IR57514 KD571-77Size expected Remark1 BADH Aroma 8 ~ 400 ~410 ~400 Polymorphic

2 RM190 Amylose content 6 ~120 ~116 ~120 124 Polymorphic

3 Waxy & Gel consistency 6 ~311 ~315 ~311 Polymorphic

4 RM204 6 ~155 ~119 ~155 169 Polymorphic

5 RM205 6 121 121 121 Monomorphic

6 RM225 6 ~145 ~120 ~145 140 Polymorphic7 RM111 Gelatinization 6 120 120 120 124 Monomorphic

8 RM50 temperature 6 200 200 200 201 Monomorphic

9 RM121 6 ~275 ~272 ~275 Polymorphic

10 PSS-1-1 6 149 149 149 Monomorphic

11 PSS2-2 6 200 no 200

12 RM136 6 290 290 290 101 Monomorphic

13 GT11 6 ~200 ~195 ~200 Polymorphic

14 RM229 11 ~119 ~119 200 116 ?

15 RM457 11 ~230 ~232 ~230 230 Polymorphic

16 RM21 11 no no no 157 ?

17 RM473E 11 141, 139 122,119,118 118 Multiple bands

117 117,116 (repeat)

18 RM206 11 ~160 ~148 ~120 147 ? (repeat)

19 RM254 11 ~156 ~156 ~153 165 ?

20 PB7-8 Bacterial leaf blight(Xa21) 11 no no no ? (repeat)21 RBO 783 Submergence tolerance 9 375 ~350 ~350 Monomorphic

Expected size (bp) Survey of SSR markers for parent screening

1 KD2 IR575143 KD571-77

1 2 3R

M59

7R

M19

0

RM

204

RM

205

RM

225

RM

111

RM

50

RM

121

RM

136

GT

11

RM

229

RM

457

RM

473E

RM

206

RM

254

RM

21

PS

S II

-1

PS

S II

-2

BA

DH

WA

XY

RM

21

RM

121

726bp

553bp500bp

427bp

311bp

249bp

200bp

151bp140bp

118bp

100bp

PCR condition

Thermal cycling

Screening parents with SSR markers

# Markers Traits ChromIR57177KD571-77Expected size (bp) Remark

1 BADH Aroma 8 ~410 ~400

2 RM190 Amylose content 6 ~116 ~120 124

3 Waxy & Gel consistency 6 ~312 ~311

4 RM204 6 ~119 ~155 169

5 GT11 Gelatinization 6 ~195 ~200

6 PSS2-2 temperature 11 Agarose

7 RM457 11 ~232 ~230 230

8 RM21 11 157 repeat

9 RM206 11 147 repeat

10 PB7-8 Bacterial leaf blight(Xa21) 11 Agarose

SSR markers chosen for parents screening

donor recipient KD571-77 X IR57514

2nd workshop on DecemberMAS for BC1F1

F1

F1 X IR57514

BC1F1

mid-October

mid-July

late-June

Planting parents

mid-November

Planting F1 and recipient parents

1 2 3 4………………………………. .200 lines

Line selection with selected SSR markers

early-April

early-August

late -November

MAS