howard rines 1 , hedera porter 1 , marty carson 2 , and jerry ochocki 2

Howard Rines1, Hedera Porter1,

Marty Carson2, and Jerry Ochocki2

1USDA-ARS Plant Science Research, and Dept. of Agronomy and Plant Genetics, Univ. of Minnesota

2USDA-ARS Cereal Disease Lab, and Dept. of Plant Pathology, Univ. of Minnesota

Introgression of Oat Crown Rust Resistance from Diploid Avena strigosa

and Tetraploid Avena murphyi

Crown Rust on Oat

Crown rust of oat

ResistancePast – major genes from A. sterilis (6x),

relatively short-lived effectiveness

Crown rust of oat

Resistance

Past – major genes from A. sterilis (6x), relatively short-lived effectiveness

Current – Pc94 from A. strigosa (2x), only effective single gene

Crown rust of oat

Resistance



Alternatives –Major gene combinationsRace non-specific – partial, adult

plant, multigenic

Crown rust of oatResistance



Alternatives – Major gene combinations Race non-specific – partial, adult

plant, multigenic

New sources – A. strigosa (2x) – CI 6954SP A. murphyi (4x) – P12

Parents Rust susceptibilityA. strigosa CI 6954 HRA. murphyi P12 HRA. sativa cv. Ogle SA. sativa cv. Black Mesdag (BM) S

Rust reaction of the parental lines.

Cross 1

A. strigosa CI6954SP X A. sativa cv. Black Mesdag (2n=2x=14) (2n=6x=42) HR embryo rescue S

F1

(2n=1x + 3x=28) S


F1

(2n=1x + 3x=28) S

colchicine fertile sectors self-pollinate C1

(2n=2x + 6x=56) S


F1

(2n=1x + 3x=28) S


(2n=2x + 6x=56) X A. sativa cv. Ogle S (2n=6x=42)

S BC1F1

partial fertile self, (1x + 3x + 3x) highly fertile female (2n=7x=49)

S


F1

(2n=1x + 3x=28) S



S BC1F1

partial fertile self, (1x + 3x + 3x) X A. sativa cv. Oglehighly fertile female (2n=7x=49) (2n=6x=42)

S S BC2F1

(2n=6x + 0-7) 18R, 62S


F1

(2n=1x + 3x=28) S



S BC1F1


S S BC2F1

BC1F2 (2n=6x + 0-7)

(2n=6x + 0-7) 18R, 62S 27R, 130S

X


F1

(2n=1x + 3x=28) S



S BC1F1


S S BC2F1 X A. sativa cv. Ogle

BC1F2 (2n=6x + 0-7) (2n=6x=42)

(2n=6x + 0-7) 18R, 62S S 27R, 130S BC3F1

(2n=6x + 0–7) 157R, 170S

X

Possible interpretations

• Suppressor in Black Mesdag– segregates out in BC1F2, BC2F1, and BC3F1 progeny


F1

(2n=1x + 3x=28) S



S BC1F1


S S BC2F1

BC1F2 (2n=6x + 0-7)

(2n=6x + 0-7) 18R, 62S 27R, 130S

X



• Precedent:– Pc62 (from A. sterilis) suppressed by Pc38– Pc94 (from A. strigosa) suppressed by Pc38




• Tested:– Pc94 x Black Mesdag --- R


• Suppressor in Black Mesdag

– segregates out in BC1F2, BC2F1, and BC3F1 progeny


• Tested:– Pc94 x Black Mesdag --- R

• Tested:– New R x Black Mesdag– New R x Pc38

Pc 38 Jerry Black(Pc 38) Mesdag

R S R S R S - - - - * 0 6 0 7 * 0 2 - - * 0 10 - - * 0 2 0 6 * 0 7 0 5 *

Pc 94 0 4 0 11 R,MR

CrossCrossOgle-c

R S 7 08 1 6 3 3 7 7 0 8 0

Plant No. Self

R S12(3) - 1 - -12(3) - 3 10 020(10) - 1 - -20(10) - 3 9 1 24(3) - 1 7 024(3) - 2 9 0

Inoculated at seedling stage with crown rust.

Test cross of resistant A. strigosa/Black Mesdag BC2F2

*crosses with Black Mesdag 35R 47S 2MR/R 3RSP

Transmission of Introduced Resistance

• Past efforts with A. strigosa sources

1. Forsberg and co-workers– Resistance present on an alien addition or

substitution chromosome, only female transmission– Used gamma irradiation treatment

2. Aung and Chong-- Resistance on an alien addition chromosome,

unstable transmission-- Induced non-homologous pairing using crosses to A.

longiglumis CW57


F1

(2n=1x + 3x=28) S



S BC1F1


S S BC2F1 X A. sativa cv. Ogle

BC1F2 (2n=6x + 0-7) (2n=6x=42)

(2n=6x + 0-7) 18R, 62S S 27R, 130S BC3F1

(2n=6x + 0–7) 157R, 170S

X

Reciprocal crosses to Ogle-C of resistant A. strigosa CI 6954SP BC3 derivatives as:

BC3 plant female male _ S R MR S R MR

12(1)-3 4 3 0 1 1 012(3)-12 4 6 0 6 4 015(6)-8 3 6 7 2 1 520(5)-19 5 3 0 2 4 020(7)-6 4 7 1 4 3 120(7)-16 7 5 2 5 4 120(10)-7 3 2 0 5 8 020(10)-17 3 6 1 1 3 020(10)-20 5 5 0 7 3 020(12)-1 2 2 6 3 7 020(12)-9 7 3 5 7 8 0

Total 47 48 22 43 46 7

Buckthorn nursery test of resistant A. strigosa BC3F2

• Plant No. R S R/S• 12(1)-1 39 16 2.4• 12(1)-7 54 14 3.9• 12(3)-5 56 15 3.7• 15(6)-19 2 26 0.1• 18(5)-4 41 13 3.2• 18(5)-10 52 19 2.7• 20(7)-6 51 15 3.4• 21(6)-6 43 5 8.6• 23(4)-15 18 0 N/A

Cross 2

A. strigosa CI6954SP X A. murphyi P12 (2n=2x=14) (2n=4x=28) HR colchicine HR

C1

(2n=2x + 4x=42) MR


C1 X A. sativa cv. Ogle (2n=2x + 4x=42) (2n=6x=42)

MR S BC1F1

(2n=1x + 2x +3X=42) S


C1 X A. sativa cv. Ogle (2n=2x + 4x=42) (2n=6x=42)

MR S

BC1F1 X A. sativa cv. Ogle (2n=1x+2x+3X=42) (2n=6x=42)

S S

BC2F1 (2n=?)

R,MR,MS,S

Summary

• Oat crown rust resistance in accessions of A. strigosa (2x) and A. murphyi (4x)

Summary


• Resistance suppressed in early generation crosses with A. sativa, but resistant segregants in later generations

Summary



• Resistance is transmitted equally via male or female. In most cases, transmission appears stable.

Summary




• Preliminary segregation data suggest most lines have a single major gene.

Summary




• Preliminary segregation data suggest most lines have a single major gene.

• Hypersensitive response of many plants further support single major gene.

Cross 3

A. sativa cv. Ogle X A. murphyi P12 (2n=6x=42) (2n=4x=28) S HR

F1

(2n=3x + 2x=35) MS, MR


F1

(2n=3x + 2x=35) MS, MR

colchicine fertile sectors self-pollinate F2 C1

(?x + ?x) (6x + 4x) 2n = ? (2n=10x=70)

S S

X


F1

(2n=3x + 2x=35) MS, MR


(?x + ?x) (6x + 4x) X A. sativa cv. Ogle 2n = ? (2n=10x=70) (2n=6x=42)

S S S BC1F1

(2n= 6x + 2x =56) S

X


F1

(2n=3x + 2x=35) MS, MR



S S S BC1F1 X A. sativa cv. Ogle (2n= 6x + 2x =56) (2n=6x=42)

S S BC2F1

(2n=6x + 0-7) S

X


F1

(2n=3x + 2x=35) MS, MR



S S S BC1F1 X A. sativa cv. Ogle (2n= 6x + 2x =56) (2n=6x=42)

S S BC1F2 BC2F1

(2n=6x + 2x=56) (2n=6x + 0-7) S, MS S

X

X

howard rines 1 , hedera porter 1 , marty carson 2 , and jerry ochocki 2

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