resistance in cotton and peanut
DESCRIPTION
Effect of Resistance on Nematode,Introgression Pathway,Comparison of Pod Yields,Known Sources of Resistance to Root-knot in Gossypium hirsutum,Sources of Resistance to Meloidogyne incognita in Gossypium hirsutum,Development of cotton with resistance to M. incognita and R. reniformisTRANSCRIPT
Resistance in Cotton and Peanut: One
success story and one story not yet finished
Jim Starr
Dept Plant Pathology & Microbiology
Texas A&M University
Resistance In Peanut
Prior to 1989, no high levels of resistance to Meloidogyne arenaria available or known in cultivated peanut
High levels of nematode resistance were identified in diploid wild Arachis species (S. C. Nelson et al., 1989)
A. cardenasii, A. diogoi, and A. batizocoi are highly resistant to M. arenaria
Diploid species are not cross-compatible with cultivated peanut
TxAG-6, a synthetic interspecific hybrid of nematode resistant diploid species, and cross-compatible with A. hypogaea(Simpson, 1991)
Introgression Pathway Developed by C. E. Simpson
A. cardenasii (AA) x A. diogoi (AA)
A. batizocoi (BB) x F1
F1 (AB)
colchicine
A. hypogaea cv. Florunner x TxAG-6
TxAG-7
(AABB)
(AABB)
A. hypogaea cv. Florunner x F1
(AABB)
(AABB)
(AA)
cv COAN released after 5 BC generations
cv NemaTAM released after 7 BC
generations
Effect of Resistance on Nematode
Population Densities
Comparison of Pod Yields
Flo
runner
Tam
run 9
6
CO
AN
Nem
aTA
M
Burow et al, 1996; Choi et al., 1999; Church, 2002
R
S
cDNA clone R2430E Linked to the
resistance locus
Current efforts - Peanuts
• Introgression of nematode resistance into genotypes that also have resistance to TSWV, Sclerotinia Blight, and the high O/L trait– Three backcross generations of NemaTAM or sister lines into
parents with these traits have been completed and yield testing has been initiated
– Hope to release multiple disease resistant peanut in 2010
Known Sources of Resistance to Root-knot
in Gossypium hirsutum
• Jackson Limbless (Orton, 1905)
• Clevewilt-6 (Jones et al., 1958)– Has been used as a source of resistance in breeding programs
• Wild Mexico Jack Jones (Minton, 1962)– Crossed with Clevewilt-6 to develop highly resistant Auburn and
M-series sources of resistance
• 18 Primitive race stocks (Shepherd, 1983)
• 5 accessions of G. hirsutum from the Yucatan region of Mexico (Robinson & Percival, 1997)
• Acala C-225 ( = Acala NemX) (Oakley, 1995)
Inheritance of Resistance to Root-
knot nematodes• Clevewilt – 6
– one recessive gene (Bezawada,2003)
– one dominant gene (Shen et al., 2007)
• Auburn and M-series– Auburn 623: More than 2 genes, incomplete
dominance, transgressive segregation (Shepherd, 1974)
– M240: 2 dominant genes (Zhou, 1999)
– M315: 1 dominant + 1 additive gene (McPherson et al., 2004)
– M78: 1 dominant gene (McPherson et al., 2004
• NemX– 1 recessive gene, transgressive segregation (Wang et
al., 2006)
CW WMJJ TX1174 TX1440 TX2076 TX2079 TX2107
DP90 X X X X X X X
CW X X X X X X
WMJJ X X X X X
TX1174 X X X X
TX1440 X X X
TX2076 X X
TX2079 X
Half-Diallele test to determine heritance and allelic relationships
among several sources of resistance to root-knot nematodes
TX 1174,TX1440, TX2076, TX2079, and TX2107 identified as resistant accessions
by Robinson and Percival, 1997.
Sources of Resistance to Meloidogyne
incognita in Gossypium hirsutum
Accession Collected Origin
Clevewilt-6 N/A N/A
Wild Mexico Jack
Jones
1951 Interior of Mexico
Tx1174* 1972 Veracruz, Mexico
Tx1440* 1979 Yucatan, Mexico
Tx2076* 1985 Tabasco, Mexico
Tx2079* 1985 Campeche, Mexico
Tx2107* 1985 Quintana Roos, Mexico
* Robinson and Percival, 1997
Half – Diallele Study
• 28 populations created
• Resistance measured as eggs/g roots from tests
conducted in a greenhouse
• Resistance was defined as a level of
reproduction that was significantly (p > 0.05)
lower than that of the susceptible control
• For each population, the two parents, the F1 and
the F2 generation was tested, along with a
susceptible control
– DP-90 was used as the susceptible control for populations for
which both parents were putatively resistant
DP 90
Clevewilt-6
Wild Mexico Jack Jones
Tx2107
Tx1440
Tx2079
Tx2076
Tx1174
2,000 4,000 6,000 8,0000 10,000 12,000
Mean eggs/g roots from seven tests
Reproduction of Meloidogyne incognita on Parental Lines
used in Half-Diallele Study
A B A
High level of reproduction on
F1 indicates recessive inheritance
Two recessive genes (9:7 ratio)
model gives best fit to observed
segregation in F2
DP90 Clevewilt F1
Eggs/
g r
oot
0
5000
10000
15000
20000
25000
30000
F2 individuals
Eggs/g
root
0
10000
20000
30000
40000
50000
DP 90 x Clevewilt-6
2 genes 1 gene
B B A
High level of reproduction on
F1 indicates recessive inheritance
Two recessive genes model
gives best fit to observed
segregation in F2
DP-90 x Wild Mexico Jack Jones
DP90 WMJJ F1
Eg
gs/
g r
oo
ts
0
2000
4000
6000
8000
10000
12000
14000
16000
F2 individuals
0 10 20 30 40 50 60 70 80
Eg
gs/g
ro
ots
0
2000
4000
6000
8000
10000
12000
2 genes 1 gene
A A A
Resistance of F1 is similar to that of
parents as expected for two resistant
parents with at least some of same
resistance genes in each parent.
That some of the F2 are highly
susceptible indicates that some of the
genes for resistance in Clevewilt are
different from those in Wild Mexico
Jack Jones.
F2 i
ndividuals
0 20 40 60
Eggs/g
root
0
5000
10000
15000
20000
25000
CW WMJJ F1
Eg
gs/g
ro
ot
0
1000
2000
3000
4000
5000
6000
Clevewilt-6 x Wild Mexico Jack Jones
DP 90 Clevewilt TX2076 F1
Eggs/g
root
0
5000
10000
15000
20000
25000
30000
Clevewilt x Tx 2076
A B BC C
That some of the F2 are highly
susceptible indicates that Clevewilt
and TX2076 have different resistance
genes
Resistance in F1 supports previous
conclusion that resistance is inherited
as a dominant trait.
F2 individuals
0 10 20 30 40 50 60 70
Eggs/g
roots
0
2000
4000
6000
8000
10000
12000
14000
Clevewilt x TX2076
0
50
100
150
200
250
300
Reproduction of Meloidogyne incognita in F1 individuals as
percentage of the susceptible parent DP90
Perc
enta
ge o
f D
P90
These data suggest that resistance in Texas accessions is inherited as a
dominant trait
Eggs/
g r
oots
0
2000
4000
6000
8000
10000
12000
14000
F2 individuals
0 10 20 30 40 50 60 70
Egg
s/g
roo
ts
0
2000
4000
6000
8000
10000
12000
14000
DP90 Tx2107 Tx1440 F1
Tx2107 x Tx1440
In this cross of two moderately
resistant parents, the resistance in the
F1 generation is similar to that of the
parental lines. The resistance in the F2
generation shows a large variation but
all individuals show at least moderate
resistance. These data suggest that
the genes for resistance in Tx2107 and
Tx1440 may be identical and have
additive effects.
Eggs/g
roots
0
1000
2000
3000
4000
5000
6000
7000
DP90 Tx1174 Tx2076 F1
Tx1197 xTx2076
In this cross of two highly resistant
individuals, the F1 generation is also
highly resistant. That no susceptible
individuals were detected in the F2
population suggests that the Tx1174
and Tx2076 have the same
resistance gene(s) .
F2 individuals
0 10 20 30 40 50 60 70
Eggs/g
roots
0
1000
2000
3000
4000
Preliminary Conclusions
• Resistance in Clevewilt and Wild Mexico Jack
Jones is inherited as a recessive trait
• Resistance in the Texas accessions is inherited
as a dominant trait
• These resistant accessions appear to have at
least some unique genes for resistance
• Because cotton is an allotetraploid, inheritance
of resistance in these genotypes does not
conform to models based on a diploid system
Preliminary Conclusions, Cont’d
• The cotton germplasm pool has numerous
genes for resistance to M. incognita
• These sources of resistance should be
useful to the cotton breeding community
for developing cotton cultivars with a broad
base of resistance
Resistance to R. reniformis
• Resistance to R. reniformis in cotton not well characterized
– Only moderate resistance known in G. hirsutum
– G. hirsutum an allotetraploid with an AD1 genome
• Some accessions of G. barbadense resistant
– G. barbadense an allotetraploid with an AD2 genome
• G. longicalyx immune, but a diploid species
Development of cotton with resistance
to M. incognita and R. reniformis
• G. hirsutum M315 (Shepherd et al, 199?)
as source of resistance to M. incognita
• G. barbadense Tx110 (Yik & Birchfield,
1984) as source of resistance to R.
reniformis
• Used a pedigree breeding strategy
– selected for day neutrality in F2 generation
– selected for resistance to R. reniformis in F3
and F4 generations
Resistance in F1 generation to Root-knot
and Reniform nematodes
0
1
2
3
4
0
20
40
60
80
100M. incognita R. reniformis
Crosses made by E. Zhou
Development of resistance to reniform nematodes– means
of each F4:5 family not different from mean of Tx110
G. b
arb
ad
en
se
Tx11
0
G. h
irsu
tum
M3
15
F4:5 families
K. Ripple, MS Thesis 2003
F7 line
M315 RNR11 RNR10 RNR14 RNR1 RNR9 RNR13 RNR12 RNR2
R.
reniform
is/5
00 c
m3 s
oil
0
20000
40000
60000
80000
100000
Resistance to Reniform And Root-knot in F7 generation
M315 F6 DP90
Gall
index (
0-5
)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Effect of aldicarb treatments on populations of reniform
nematodes on resistant and susceptible cotton
genotypes
Reniform
nem
ato
des/1
00 c
m3
soil
Effect of aldicarb on seed cotton yield of cotton genotypes
resistant and susceptible to the reniform nematode in a
nematode infested field
Seed c
otton (
g)/
3 m
row
lenght
Conclusions
• Pedigree breeding program to introgress
resistance to Reniform nematode yields
moderate success
– Resulting germplasm has moderate
resistance and poor yield
– Likely to be difficult to use in a breeding
program
• Also trying a backcross breeding progam
Colleagues –
C. E. Simpson
T. A. Lee, Jr.
A. Paterson
C, W. Smith
Post-doctoral Scientists -
M. Burow
I. Bendezue
E. Moresco
Support staff –
S. McBride
E. Tomaszewski
E. Morgan
L. Torrez
A. Grim
Graduate Students -
Peanut - Cotton -
T. Wheeler E. Zhou
S. Nelson K. Ripple
S. Abdel-Molmen T. Faske
M.Y. Shim
K. Choi
G. Church
Funding –
Cotton Incorporated
National Peanut Board
Texas Peanut Producers
USDA- NRI
Texas Higher Education Coordinating Board