Howard Rines1, Hedera Porter1,

1
Introgression of Oat Crown Rust Resistance from
Diploid Avena strigosa and Tetraploid Avena
murphyi

• 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

2
Crown Rust on Oat
3
Crown rust of oat

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

4
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

5
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
• Alternatives Major gene combinations
• Race non-specific partial, adult plant,
  multigenic

6
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
• Alternatives Major gene combinations
• Race non-specific partial, adult plant,
  multigenic
• New sources A. strigosa (2x) CI 6954SP
• A. murphyi (4x) P12

7
Rust reaction of the parental lines.
Parents Rust susceptibility A. strigosa CI
6954 HR A. murphyi P12 HR A. sativa cv.
Ogle S A. sativa cv. Black Mesdag (BM) S
8
Cross 1
9
A. strigosa CI6954SP X A. sativa cv.
Black Mesdag (2n2x14)
(2n6x42) HR embryo
rescue S F1 (2n1x 3x28)
S
10
A. strigosa CI6954SP X A. sativa cv.
Black Mesdag (2n2x14)
(2n6x42) HR embryo
rescue S F1 (2n1x 3x28)
S colchicine fertile sectors
self-pollinate   C1 (2n2x
6x56) S
11
A. strigosa CI6954SP X A. sativa cv.
Black Mesdag (2n2x14)
(2n6x42) HR embryo
rescue S F1 (2n1x 3x28)
S colchicine fertile sectors
self-pollinate   C1 (2n2x 6x56)
X A. sativa cv. Ogle S
(2n6x42) S
BC1F1   partial
fertile self, (1x 3x 3x) highly
fertile female (2n7x49)
S
12
A. strigosa CI6954SP X A. sativa cv.
Black Mesdag (2n2x14)
(2n6x42) HR embryo
rescue S F1 (2n1x 3x28)
S colchicine fertile sectors
self-pollinate   C1 (2n2x 6x56)
X A. sativa cv. Ogle S
(2n6x42) S
BC1F1   partial
fertile self, (1x 3x 3x) X A.
sativa cv. Ogle highly fertile female
(2n7x49) (2n6x42)
S S BC2F1
(2n6x 0-7)
18R, 62S
13
A. strigosa CI6954SP X A. sativa cv.
Black Mesdag (2n2x14)
(2n6x42) HR embryo
rescue S F1 (2n1x 3x28)
S colchicine fertile sectors
self-pollinate   C1 (2n2x 6x56)
X A. sativa cv. Ogle S
(2n6x42) S
BC1F1   partial
fertile self, (1x 3x 3x) X A.
sativa cv. Ogle highly fertile female
(2n7x49) (2n6x42)
S S BC2F1
BC1F2 (2n6x 0-7)
(2n6x 0-7) 18R, 62S
27R, 130S
X
14
A. strigosa CI6954SP X A. sativa cv.
Black Mesdag (2n2x14)
(2n6x42) HR embryo
rescue S F1 (2n1x 3x28)
S colchicine fertile sectors
self-pollinate   C1 (2n2x 6x56)
X A. sativa cv. Ogle S
(2n6x42) S
BC1F1   partial
fertile self, (1x 3x 3x) X A.
sativa cv. Ogle highly fertile female
(2n7x49) (2n6x42)
S S BC2F1
X A. sativa cv. Ogle BC1F2
(2n6x 0-7)
(2n6x42) (2n6x 0-7) 18R, 62S
S 27R, 130S
BC3F1 (2n6x 07)
157R, 170S
X
15
Possible interpretations

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

16
A. strigosa CI6954SP X A. sativa cv.
Black Mesdag (2n2x14)
(2n6x42) HR embryo
rescue S F1 (2n1x 3x28)
S colchicine fertile sectors
self-pollinate   C1 (2n2x 6x56)
X A. sativa cv. Ogle S
(2n6x42) S
BC1F1   partial
fertile self, (1x 3x 3x) X A.
sativa cv. Ogle highly fertile female
(2n7x49) (2n6x42)
S S BC2F1
BC1F2 (2n6x 0-7)
(2n6x 0-7) 18R, 62S
27R, 130S
X
17
Possible interpretations

• Suppressor in Black Mesdag
• segregates out in BC1F2, BC2F1, and BC3F1 progeny
• Precedent
• Pc62 (from A. sterilis) suppressed by Pc38
• Pc94 (from A. strigosa) suppressed by Pc38

18
Possible interpretations

• Suppressor in Black Mesdag
• segregates out in BC1F2, BC2F1, and BC3F1 progeny
• Precedent
• Pc62 (from A. sterilis) suppressed by Pc38
• Pc94 (from A. strigosa) suppressed by Pc38
• Tested
• Pc94 x Black Mesdag --- R

19
Possible interpretations

• Suppressor in Black Mesdag
• segregates out in BC1F2, BC2F1, and BC3F1 progeny
• Precedent
• Pc62 (from A. sterilis) suppressed by Pc38
• Pc94 (from A. strigosa) suppressed by Pc38
• Tested
• Pc94 x Black Mesdag --- R
• Tested
• New R x Black Mesdag
• New R x Pc38

20
Test cross of resistant A. strigosa/Black Mesdag
BC2F2
Cross Ogle-c R S
7 0 8 1 6 3
3 7 7 0 8 0
Plant No. Self R S 12(3) - 1 -
- 12(3) - 3 10 0 20(10) - 1 -
- 20(10) - 3 9 1 24(3) - 1 7
0 24(3) - 2 9 0 Inoculated at seedling
stage with crown rust.
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
crosses with Black Mesdag 35R 47S 2MR/R
3RSP
21
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

22
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

23
A. strigosa CI6954SP X A. sativa cv.
Black Mesdag (2n2x14)
(2n6x42) HR embryo
rescue S F1 (2n1x 3x28)
S colchicine fertile sectors
self-pollinate   C1 (2n2x 6x56)
X A. sativa cv. Ogle S
(2n6x42) S
BC1F1   partial
fertile self, (1x 3x 3x) X A.
sativa cv. Ogle highly fertile female
(2n7x49) (2n6x42)
S S BC2F1
X A. sativa cv. Ogle BC1F2
(2n6x 0-7)
(2n6x42) (2n6x 0-7) 18R, 62S
S 27R, 130S
BC3F1 (2n6x 07)
157R, 170S
X
24
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 0
• 12(3)-12 4 6 0 6 4 0
• 15(6)-8 3 6 7 2 1 5
• 20(5)-19 5 3 0 2 4 0
• 20(7)-6 4 7 1 4 3 1
• 20(7)-16 7 5 2 5 4
  1
• 20(10)-7 3 2 0 5 8 0
• 20(10)-17 3 6 1 1 3 0
• 20(10)-20 5 5 0 7 3 0
• 20(12)-1 2 2 6 3 7 0
• 20(12)-9 7 3 5 7 8 0
• Total 47 48 22
  43 46 7

25
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

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Cross 2
27
A. strigosa CI6954SP X A. murphyi
P12 (2n2x14) (2n4x28)
HR colchicine
HR C1 (2n2x 4x42)
MR
28
A. strigosa CI6954SP X A. murphyi
P12 (2n2x14) (2n4x28)
HR colchicine
HR C1 X A. sativa cv.
Ogle (2n2x 4x42)
(2n6x42) MR S
BC1F1   (2n1x 2x
3X42) S
29
A. strigosa CI6954SP X A. murphyi
P12 (2n2x14) (2n4x28)
HR colchicine
HR C1 X A. sativa cv.
Ogle (2n2x 4x42)
(2n6x42) MR S
BC1F1 X A. sativa
cv. Ogle   (2n1x2x3X42)
(2n6x42) S S
BC2F1
(2n?) R,MR,MS,S
30
Summary

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

31
Summary

• Oat crown rust resistance in accessions of
  A. strigosa (2x) and A. murphyi (4x)
• Resistance suppressed in early generation crosses
  with A. sativa, but resistant segregants in later
  generations

32
Summary

• Oat crown rust resistance in accessions of
  A. strigosa (2x) and A. murphyi (4x)
• Resistance suppressed in early generation crosses
  with A. sativa, but resistant segregants in later
  generations
• Resistance is transmitted equally via male or
  female. In most cases, transmission appears
  stable.

33
Summary

• Oat crown rust resistance in accessions of
  A. strigosa (2x) and A. murphyi (4x)
• Resistance suppressed in early generation crosses
  with A. sativa, but resistant segregants in later
  generations
• Resistance is transmitted equally via male or
  female. In most cases, transmission appears
  stable.
• Preliminary segregation data suggest most lines
  have a single major gene.

34
Summary

• Oat crown rust resistance in accessions of
  A. strigosa (2x) and A. murphyi (4x)
• Resistance suppressed in early generation crosses
  with A. sativa, but resistant segregants in later
  generations
• Resistance is transmitted equally via male or
  female. In most cases, transmission appears
  stable.
• Preliminary segregation data suggest most lines
  have a single major gene.
• Hypersensitive response of many plants further
  support single major gene.

35
Cross 3
36
A. sativa cv. Ogle X A. murphyi P12
(2n6x42) (2n4x28)
S HR
F1 (2n3x 2x35)
MS, MR
37
A. sativa cv. Ogle X A. murphyi P12
(2n6x42) (2n4x28)
S HR
F1 (2n3x 2x35)
MS, MR colchicine
fertile sectors self-pollinate  
F2 C1 (?x ?x)
(6x 4x) 2n ?
(2n10x70) S S
X
38
A. sativa cv. Ogle X A. murphyi P12
(2n6x42) (2n4x28)
S HR
F1 (2n3x 2x35)
MS, MR colchicine
fertile sectors self-pollinate  
F2 C1 (?x ?x)
(6x 4x) X A. sativa cv. Ogle
2n ? (2n10x70)
(2n6x42) S S
S
BC1F1  
(2n 6x 2x 56)
S
X
39
A. sativa cv. Ogle X A. murphyi P12
(2n6x42) (2n4x28)
S HR
F1 (2n3x 2x35)
MS, MR colchicine
fertile sectors self-pollinate  
F2 C1 (?x ?x)
(6x 4x) X A. sativa cv. Ogle 2n
? (2n10x70)
(2n6x42) S S
S
BC1F1 X A.
sativa cv. Ogle   (2n
6x 2x 56) (2n6x42)
S S
BC2F1
(2n6x 0-7)
S
X
40
A. sativa cv. Ogle X A. murphyi P12
(2n6x42) (2n4x28)
S HR
F1 (2n3x 2x35)
MS, MR colchicine
fertile sectors self-pollinate  
F2 C1 (?x ?x) (6x
4x) X A. sativa cv. Ogle 2n
? (2n10x70)
(2n6x42) S S
S
BC1F1 X A.
sativa cv. Ogle   (2n
6x 2x 56) (2n6x42)
S S BC1F2
BC2F1 (2n6x
2x56) (2n6x 0-7)
S, MS S
X
X
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