30
Chapter 2. Identification and Genetic Analysis of Major Genes for
Wheat Powdery Mildew Resistance
Wheat powdery mildew, caused by Blumeria graminis (DC.) E.O. Speer f. sp. tritici
Em. Marchal (Bgt) = Erysiphe graminis DC. ex Merat f. sp. tritici Em. Marchal, is a
disease of major importance. Damage caused by this disease results in yield loss every year
in many wheat producing regions, including China, Germany, Japan, Russia, United
Kingdom, South and West Asia, North and East Africa, and the Southeastern United States
(Bennett 1984, Leath et al. 1989, 1990). In the United States, powdery mildew is prevalent
in the soft red winter growing regions, and can cause yield losses of approximately 12%,
27%, and 34% in the Midwest, East and Southeast, respectively (Leath et al. 1990). In
North Carolina, powdery mildew epidemics occur yearly, and yield suppression in the
susceptible cv. Saluda can be 17% when disease severity reaches 19% on the flag leaf by
the time of head emergence (Leath et al. 1989, 1990). Losses of 10-15% can occure from
natural inoculum in winter wheat due to powdery mildew (Bowen et al. 1991). Fried et al
(1981) reviewed previous work and reported that yield losses attributed to wheat powdery
mildew varied from 0 to 45%.
The use of single gene resistance is the primary method of control of powdery
mildew. Thirty-one major alleles at 25 resistance loci have been identified in wheat. Most
alleles were transferred from wild relatives (McIntosh, personnel communication).
However, genes for resistance are frequently overcome by new Bgt isolates, because the
presence and frequency of virulence genes in the pathogen population varies continuously
(Leath & Murphy,1985, Menzies et al, 1986, Limpert et al. 1987, Namuco et al. 1987).
31
The common management strategy has been to replace cultivars when their resistance is no
longer effective ( Wolf, 1984, Leath & Heun, 1990).
Molecular markers, tightly linked to disease resistance genes, can provide breeders
with a tool for marker-assisted selection of resistance gene in plants (Stuber, 1992,
Michelmore et al.., 1995). Among the 25 major gene loci for powdery mildew resistance in
wheat, restriction fragment length polymorphism (RFLP) markers associated with the Pm1,
Pm2, Pm3, Pm4a, Pm12, Pm13, and Pm18 alleles, and random amplified polymorphic
DNA (RAPD) markers associated with the Pm1, Pm2, Pm3b, Pm4a, Pm12, Pm18, Pm21,
and Pm25 alleles plus the Pm3 locus have been identified (Donini et al. 1995, Hartl et al.
1993, 1995, Hu et al. 1997, Jia et al. 1996, Ma et al. 1994, Mohler and Jahoor, 1996,
Nelson et al. 1995, Qi et al. 1993, 1996, Shi et al. 1995, 1997a,b, Chapter 3,4,5,6).
This review focuses on major genes for wheat powdery mildew resistance,
identification and transfer of powdery mildew resistance alleles from wild relatives to
common wheat, and molecular markers associated with wheat powdery mildew resistance.
1. Major genes for wheat powdery mildew resistance
1.1. Pm series genes
Thirty Pm alleles at 25 loci have been nominated for wheat powdery mildew
resistance (McIntosh, personnel communication). Twenty-five alleles at 19 loci from Pm1
to Pm19, their locations at chromosomes, and their sources have been were reviewed
(McIntosh et al. 1995). Other Pm alleles, Pm20, Pm21, and Pm22 have been reported
(Friebe et al. 1994, Qi et al. 1995, Peusha et al. 1996) and Pm25 has been identified (Shi et
al. 1997a). Pm1, Pm2, Pm3 (3a, 3b, 3c, 3d, 3e, and 3f), Pm9, Pm18, and Pm22, were found
in the hexaploid common wheat (Triticum aestivum L.); Pm2 and Pm19 were derived from
32
Aegilops tauschii Coss (2n=14, DD); Pm4a and pm5, from T. dicoccum (2n=28, AABB);
Pm4b, from T. carthlicum (2n=28, AABB); Pm6, from T. timopheevii (2n=28, AAGG);
Pm7, Pm8, Pm17, and Pm20, from Secale cereale (2n=14, RR); Pm12, from Ae. speltoides
(2n=14, SbSb); Pm13, from Ae. longissima (2n=14, SpSp); Pm16, from T. turgidum var.
dicoccoides;
Pm21, from Dasypyrum villosum (2n=14, VV); and Pm25, from T.
monococcum ssp. aegilopoides. Pm10, Pm11, Pm14, and Pm15 originated in T. spelta
duhamelianum and Ae. tauschii var. agropyri but they are not effective against Bgt.
Because Pm10, Pm11, Pm14, and Pm15 were not effective against Bgt isolates, it is
suggested here to use other symbols for naming the four genes, such as Bga1, Bga2, Bga3,
and Bga4 instead of Pm10, Pm11, Pm14, and Pm15.
1.2. Other Pm genes
The gene Mld for wheat powdery mildew resistance was located on chromosome 4B
in the wheat lines, Halle 13471, H8810/47, and Maris Dove. It was transferred from T.
durum (McIntosh et al. 1995). Zeller et al. (1993) reported three wheat cultivars, Abo,
Aristide, and Courtot, contained a major gene, Mlar, for resistance to the German Bgt
isolate no.2. Liu et al. (1989) reported that the variety Kenguia 1 contained a new genes,
KG, for powdery mildew resistance, which was located on chromosome 6A. Robe and
Doussinault (1995) reported that the line RF714 contained a new recessive gene, mlre, for
wheat powdery mildew resistance, which was derived from a cross between Aegilops
squarrosa 33 and Triticum dicoccum 119. They postulated that mlre was derived from T.
dicoccum. A new recessive gene, pmTD1, was identified in the wheat line NC92-8562
transferred from Ae. tauschii ssp. tauschii (Shi et al. 1997, unpublished).
1.3 Dominant and recessive alleles
33
In Flor's gene for gene hypothesis, the resistance gene in the host and the
avirulence gene in the pathogen were dominant (Flor, 1956, 1971). In reality, recessive
resistance genes in the host are frequent. de Wit (1992) thought disease resistance might
be inherited as a recessive factor as frequently as a dominant factor in natural populations.
Because they were easily detected and selected, the dominant genes were frequently
observed in cultivars. Many recessive genes for plant disease resistance have be
identified: xa5 and xa13 for bacterial blight in rice (Ogawa, T. 1987); ht2and htn1 for
northern leaf blight in maize (Simcox and Bennetzen, 1993); rh6 and rh8 for scald on
barley (Goodwin et al. 1990).
Jorgensen (1993) reported the Mlo resistance was
conferred by a series of recessive, non-complementing alleles from mlo1 to mlo11 at
locus mlo on the long arm of barley chromosome 4.
For powdery mildew resistance, Randhawa et al. (1989) reported the wheat line
CPAN 1946 contained two recessive genes; Robe and Doussinault (1995) reported RF714
contained a new recessive gene, mlre.
Among thirty major series Pm genes, pm5 and
pm9 were reported as recessive (Lebsock and Briggle, 1974, Schneider et al. 1991). Pm8
in the wheat line VPM1 was identified to be recessive (Chung and Griffey, 1995a,
1995b). Shi et al (1997) identified the genes Pm9, Pm17, and Pm19 as recessive, and
Pm4b, Pm13, and Pm20 revealed recessive behavior (unpublished). Therefore, gene
symbols pm5, pm8, pm9, pm17, and pm19 are proposed to be used instead of Pm5, Pm8,
Pm9, Pm17, and Pm19. Because pm17 is located at the same locus as pm8 in rye
chromosome 1RS (Zeller, 1973, Heun and Friebe, 1990), it also is suggested to use pm8b
instead of pm17.
Four new wheat lines, GA8610-D1, GA8619-D6, VA91-52-19, and
34
NC92-8562, were found to contain one recessive gene for wheat powdery mildew resistance
(Shi et al, 1997, unpublished).
1.4. Linkage and multialleles
pm9 is linked to Pm1 (r = 8.5 cM) on chromosome 7AL in Normandie (Schneider et
al. 1991).
pm17 is linked to Pm3 on the 1AL-1RS translocation chromosome in Amigo
(Heun et al. 1990). Pm18 is linked to Pm1 on chromosome 7AL in M1N (Hartl et al. 1995).
Pm25 is linked to Pm3a on chromosome 1A in NC96BGTD5 (r = 0.21) (Shi et al. 1997a).
Pm3 has five alleles: 3a, 3b, 3c, 3d, 3e, 3f, and Pm4 has two alleles:4a and 4b (McIntosh et
al. 1995).
1.5. Reactions to different isolates
Schneider et al. (1991) analyzed cosegregation of resistance to different Bgt isolates
and found that Normandie contained three genes Pm1, Pm2, and pm9. pm9 was linked to
Pm1 (r = 8.5 cM). Shi et al. (1997b) identified the reactions to six isolates, E314, 209a2,
#8, 137a, 153a2, and Wkin91, of Bgt in the P1, P2, F1, F2, and BC1F1 generations derived
from the cross between Line #31 containing the Pm12 resistance gene and a susceptible
cultivar NK-Coker 68-15. The resistance to E314 and 209a2 was controlled by three
independent dominant genes, resistance to 137a1 and #8 was controlled by two independent
dominant genes, and resistance to 153a2 and Wkin91 was controlled by one dominant gene
in Line #31. Analysis of cosegregations of resistance to Bgt indicated that Line #31
contained three dominant genes.
One was Pm1, another was Pm12, and the third was
postulated to be Pm2.
2. Resistance alleles transferred from wild wheat relatives
2.1. Aegilops tauschii
35
Aegilops tauschii Coss (2n=2x=14, DD) has proved to be a valuable relative for
wheat breeding and diversifying disease resistance (Gill et al. 1986, Cox et al. 1992).
Genes Lr21, Lr22a, Lr32, Lr39, Lr40, Lr41, Lr42, and Lr43, for leaf rust resistance were
derived from A. tauschii (Cox, et al. 1994, McIntosh et al. 1995). In addition, genes for
resistance to stem rust (Innes et al. 1994), stripe rust (Ma et al. 1995), and take-all fungus
(Eastwood et al. 1993), have been transferred into common wheat from A. tauschii.
For wheat powdery mildew resistance, Gill et al. (1986) reported on the reactions of
60 accessions of A. tauschii to four Bgt isolates. Among the 60 accessions, four showed an
immune reaction, seven were highly resistant, and 20 were moderately resistant. Singh et al
(1988) reported that 85% of 282 accessions from Aegilops species were classified as
resistant. Cox et al. (1992) evaluated 30 A. tauschii accessions resistant to two isolates, 2
and 7-12, of Bgt. Among them, resistant and moderately resistant types totaled 87% and
93% to each isolate, respectively. Two resistance alleles, Pm2 and pm19, were transferred
into common wheat from A. tauschii (Lutz et al. 1995). Although Pm10 and Pm15 are not
effective against Bgt , they can be traced from A. tauschii (McIntosh et al. 1995). Three
new germplasm lines, NC96BGTD1, NC96BGTD2, and NC96BGTD3 were released with
wheat powdery mildew resistance alleles, which were transferred from A. tauschii (Murphy
et al. 1997a). Shi et al (1997) identified new allele(s) for powdery mildew resistance
transferred from Ae. tauschii ssp. tauschii in NC92-8562 and NC109-2-1-G1-1.
2.2. Triticum monococcum L. ssp. aegilopoides
Wild einkorn (Triticum monococcum L. ssp. aegilopoides (Link) Thell =T.
boeoticum) (2n=2x=14, AA) is a valuable source of genes for diversifying fungal disease
resistance in wheat also. Valkoun et al. (1986) reported on reaction to leaf rust in four
36
accessions of T. monococcum L. ssp. aegilopoides and three of them were resistant. A
gene, Sr22, for wheat stem rust resistance was derived from T. monococcum ssp.
aegilopoides (Paul et al. 1994).
A new common wheat germplasm NC96BGTA5,
containing a new gene Pm25, was released (Murphy et al. 1997b, Shi et al. 1997a).
2.3. Triticum turgidum ssp. dicoccoides
Triticum turgidum ssp. dicoccoides (= T. dicoccoides, 2n=4x=28, AABB) is a very
useful source for diversifying fungal resistance in wheat. A resistance gene, Yr15, was
derived from T. dicoccoides (Gerechter-Amitai, et al. 1989). Sharma et al. (1995) evaluated
38 wild emmer derivatives for yellow rust resistance, and many of them were resistant to all
tested isolates. They contained new alleles for yellow rust resistance.
Krivchenko et al. (1979) determined the reactions of 29 T. dicoccoides samples to
wheat powdery mildew. Twenty-eight were resistant in the field, and fifteen were resistant
in the seedling stage. Moseman et al. (1984) reported on the reactions to powdery mildew
of 233 T. dicoccoides acessions. Resistance to at least one isolate was found in 149
accessions, and 137 expressed intermediate to complete resistance to four Bgt isolates.
Paramjit-Singh et al. (1987) reported on resistance to powdery mildew and yellow rust in
109 T. dicoccoides accessions. Gerechter-Amitai & Van Silfhout (1984) found the wild
emmer entries displayed a diversity of responses to wheat powdery mildew infection,
ranging from highly resistant to completely susceptible.
A major gene, Pm16, was
transferred into wheat from T. turgidum ssp. dicoccoides (Reader and Miller, 1991).
A new germplasm, NC97BGTAB10, with resistance derived from this wild relative
is being released by NC State (Murphy et al. 1997). NC97BGTAB10 is resistant to all
tested Bgt isolates in detatched leaf tests, and showed high level of resistance in the
37
greenhouse and field in North Carolina. A resistance gene, different from Pm16, has been
successfully transferred from T. turgidum ssp. dicoccoides into the common wheat line
NC94-M5 (NC97BGTAB10) (Shi et al. 1997c).
2.4. Aegilops speltoides
Gene Pm12 for resistance to wheat powdery mildew was introgressed from Aegilops
speltoides (2n=2x=14, SpSp) into the UK spring wheat cultivar Wembley (Miller et al,
1988). Miller et al (1988) reported Line #31 contained a single dominant resistance gene,
and the gene was designated Pm12 and located on chromosome 6A. Nevertheless, Jia et al.
(1996) concluded Pm12 was located on the short arm of translocation chromosome 6BS6SpS.6SpL in Line #31 by use of RFLP-based maps of the homoeologous group-6
chromosome of wheat. Shi et al. (1997b) identified three dominant genes, Pm1, Pm2, and
Pm12, in Line #31.
2.5. Dasypyrum villosum
Dasypyrum villosum (2n=2x=14, VV) (Syn. Haynaldia villosa, Triticum villosum)
is a potentially valuable source for resistance to fungal diseases (Linde-Laursen et al.
1973, Scott 1981, De Pace et al. 1988, Murray et al. 1994). De Pace et al. (1988) reported
that an amphihexaploid (Mxv) (2n=6x=42, AABBVV) derived from Triticum turgidum
var durum cv 'Modoc' x D. villosum and an amphioctoploid derived from T. aestivum x
D. villosum were immune to both Bgt and Erysiphe graminis f. sp. haynaldiae. Chen et
al. (1997) reported D. villosum was resistant to more than 80 isolates of Bgt collected
from the USA, UK, Germany, and China. The resistance gene Pm21 was transferred
from D. villosum into common wheat and a series of 6A/6V disomic substitution lines
and 6AL-6VS translocation lines were developed (Liu et al. 1988, Chen et al. 1995, Qi et
38
al. 1995, 1996).
These wheat lines with Pm21 all have black awns, which is closely
linked to the Pm21 locus Therefore, it is difficult to transfer Pm21 into cultivars without
dragging the alleles for black awn. Chen et al. (1996) made crosses between D. villosum
and T. durum in 1983, and has successfully transferred powdery mildew resistance into T.
aestivum utilizing immature embryo and anther culture. Five amphiploids (2n=6x=42,
AABBVV) and a series of 6D/6V disomic substitution lines (2n=6x=42, AABBDD'6D/6V) were produced (Chen et al. 1996, Shang et al. 1997). These 6D/6V substitution
lines also contained the Pm21 resistance allele postulated by allelism test and linked RAPD
marker analysis (Chapter 6). Because all these 6D/6V wheat lines did not express the black
awn trait and were immune or highly resistant to wheat powdery mildew, the resistance is
now likely to be utilized in cultivar development.
2.6. Secale cereale
Four major genes for wheat powdery mildew resistance, Pm7, Pm8, Pm17, and
Pm20, were derived from Secale cereale (2n=2x=14, RR). Pm7 is located on the long arm
of rye chromosome 5 and is present in the wheat germplasm Transec in the form of a
T4BS.4BL-5RL wheat-rye chromosome translocation (Heun et al., 1990). Pm7 expresses
its resistance in mature plants only (Bennett 1984). Pm8 and Pm17 are located on the short
arm of rye chromosome 1. Pm8 is on the T1BL-1RS, and Pm17 on the T1AL-1RS wheatrye translocation lines (McIntosh et al. 1995). Pm20 is located on the long arm of the rye
chromosome 6 in the T6BS.6RL wheat-rye translocation line (Friebe et al. 1994).
2.7. Triticum timopheevi
Tomerlin et al. (1984) reported four accessions of T. timopheevi were highly
resistance to two Bgt isolates. A major gene, Pm6, has been transferred from T. timopheevi
39
into common wheat lines, CI12632, CI12633, and TP114 (McIntosh et al., 1995). BrownGuedira et al. (1996) tested the reactions to two isolates in 28 accessions of T. timopheevi
and found over half were highly resistant to powdery mildew.
2.8. Aegilops ventricosa
Delibes et al. (1987) reported two wheat lines, H93-8 and H93-35 carried a wheat
powdery mildew resistance gene from A. ventricosa (genomes DVMV), linked to a gene
encoding the marker protein U1.
2.9. Aegilops variabilis
Ae. variabilis Eig (=Triticum peregrinum Hackel, 2n=4x=28, UUSS) has been
recognized as a source of genes for resistance to stem rust, cereal cyst nematode, root knot
nematode, and powdery mildew (Spetsov et al. 1997). Several wheat lines with 44- and 42chromosomes were derived from crosses to the winter wheat variety, Rusalka and an
accession of Ae. Variabilis showed resistance to powdery mildew (Spetsov et al. 1997).
2.10. Triticum ovatum
Friebe and Heun (1989) reported two T. aestivum- ovatum addition lines were
highly resistant to two isolates of Bgt.
3. Molecular markers associated with wheat powdery mildew resistance
3.1. Identification of markers linked to genes
3.1.1 Screening of molecular markers
Near-isogenic lines (NILs) have been the main method used for screening molecular
markers associated with major genes of powdery mildew resistance in wheat.
Six
‘Chancellor’ near-isogenic lines (NILs) carrying single Pm resistance genes, Pm1, Pm2,
Pm3a, Pm3b, Pm3c, and Pm4a, have been developed (Briggle, 1969). The availability of
40
such lines has greatly facilitated the identification of molecular markers associated with
major genes (Hartl et al. 1993, 1995, Ma et al. 1994, Shi et al. Chapter 3).
Bulked
segregant analysis (BSA) also has been used to screen molecular markers associated with
genes, Pm1 and Pm25, for powdery mildew resistance in wheat (Wu et al 1997, Shi et al.
1997a).
Because most major genes for powdery mildew resistance in common wheat were
transferred from wild wheat relatives, and many translocation and substitution lines have
been developed (McIntosh et al. 1995), screening of markers can be conducted by use of a
resistant translocation line, or a substitution line. Fourteen RAPD markers have been found
to be associated with Pm21 by the use of this method (Qi et al. 1993, 1996, Shi et al.
Chapter 6).
3.1.2 Estimate of linkage
The recombination frequency ( r ) can be estimated by the maximum likelihood
estimator based on a segregating population, usually F2 or BC1F1 populations. This was
described in detail in Chapter 1.
3.1.3 Examples of previously identified genes
Thirteen RFLP markers have been identified as linked to Pm1, Pm2, Pm3b, Pm4a,
Pm12, and Pm18 (Ma et al. 1994, Hartl et al. 1993, 1995, Jia et al. 1996), and eighteen
RAPD markers as linked to Pm1, Pm3b, Pm3 locus, Pm12, Pm18, Pm25, and pmTD1 (Hu
et al. 1997, Hartl et al. 1995, Shi et al. 1995, 1997a,b, Chapter 3,4,5,6), and one STS marker
las inked to Pm2 (Mohler and Jahoor, 1996) (Table 1).
More than forty RAPD markers and two RFLP markers have been identified to be
associated with Pm1, Pm2, Pm3a, Pm3b, Pm3c, Pm4a, and Pm21 (Hartl et al. 1993, Ma et
41
al. 1994, Qi et al. 1993, 1996, Shi et al., Chapter 3 and 6) (Table 2). But the linkage
between the genes and these associated markers have not identified.
3.2. Mapping of major gene alleles
The development of genetic maps of wheat is now adding a new dimension for
identification of molecular markers associated with powdery mildew resistance genes.
Screening markers can be conducted in the two parents, by selecting several markers on
each chromosome of the genetic map, and then linkage between the allele for resistance and
the polymorphic markers in the two parents can be estimated by use of QTL statistical
analysis based on the data from a segregating population. Five major genes have been
mapped using this method: Pm1, on the chromosome 7AL, Pm2, on the chromosome 5DS
(Nelson et al. 1995); Pm3, on the chromosome 1AS (Van Deynze et al. 1995); Pm4a, on
the chromosome 2AL (Ma et al. 1994); Pm12, on chromosome 6BS.6SS (Jia et al. 1996);
and Pm13, on chromosome 3BS, or 3DS (Donini et al. 1996).
42
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51
Table 1. Previously identified molecular markers linked to major genes for wheat powdery mildew resistance
__________________________________________________________________________________________________________
Gene Type of markers
Method
Marker
Recombination distance
Reference
(cM)
__________________________________________________________________________________________________________
Pm1
RAPD
NILs
OPU17750
2.2  1.07
Shi et al. Chapter 3
RAPD
BSA
UBC320420, UBC638550
0.0
Hu et al. 1997
5.4  1.9
0.0
2.8  2.7
Ma et al. 1994
Hartl et al. 1995
RFLP
RFLP
NILs
NILs
OPF12650
Xcdo 347
Xwhs178
Pm2
RFLP
RFLP
RFLP, STS
NILs
NILs
NILs
Xbcd 1871
Xwhs 295
Xwhs 350, Xwhs 350-1,2
3.5
2.7  2.6
3.8
Ma et al. 1994
Hartl et al, 1995
Mohler & Jahoor, 1996
Pm3b
RAPD
RFLP
RFLP
NILs
NILs
NILs
OPAN071200
Xwhs 179
Xbcd 1434
1.2  0.85
3.3  1.9
1.3
Shi et al. Chapter 3
Hartl et al. 1993
Ma et al. 1994
Pm3 locus
RAPD
NILs
OPN09600, OPN091200, OPS031400
0.0 - 0.15
Shi et al. 1995
Pm4a
RFLP
NILs
Xcdo 678, Xbcd 1231-(2)
0.0
Ma et al. 1994
Xbcd 1231-(1), Xbcd 292
1.5
_________________________________________________________________________________________________________
52
Table 1. Continue
__________________________________________________________________________________________________________
Gene Type of markers
Method
Marker
Recombination distance
Reference
(cM)
_________________________________________________________________________________________________________
Pm12
RAPD
PP, BSA
OPAH05580
1.6  0.03
Shi et al. 1997b
OPAI13490
6.6  0.10
OPAE12495
OPAE121350
4.9  0.08
3.3  0.05
RFLP
GMBA
X-Amy-1
1.1
Jia et al. 1996
Pm18
RFLP
RAPD
GMBA
BSA
Xwhs 178
OPH111900
4.4  3.6
13  16
Hartl et al 1995
Pm25
RAPD
BSA
OPX061050
OPAG04950
OPAI14600
12.8  3.96
15.5  4.29
19.7  4 72
Shi et al. 1997a
Chapter 5
pmTD1
RAPD
PP, PGA
OPQ09750
5.6  0.03
Shi et al. unpublished
__________________________________________________________________________________________________________
NILs = near-isogenic lines, BSA = bulked segregant analysis, PP = parents, GMBA = genetic map-based analysis,
and PGA = pedigree analysis
53
Table 2. Previously identified molecular markers associated with major genes for wheat powdery mildew resistance
__________________________________________________________________________________________________________
Gene
Type of markers Method
Marker
Reference
__________________________________________________________________________________________________________
Pm1
RAPD
NILs
OPAC08950, OPAI02800, OPAL141400
Shi et al. chapter 3
RFLP
NILs
Xcdo 512
Ma et al. 1994
Pm2
RAPD
NILs
OPT16850
Shi et al. chapter 3
Pm3a
RAPD
NILs
OPB19800, OPB20600, OPB201850 ,
OPS111300, OPS111700, OPS13450,
Shi et al. chapter 3
Pm3b
RAPD
NILs
OPD011200, OPH192000, OPS15650,
OPT151550, OPAD162050, OPAJ062200
Shi et al. chapter 3
Pm3c
RAPD
NILs
OPT09490, OPT091750, OPT12700
Shi et al. chapter 3
Pm3 locus
RFLP
NILs
Xwhs 179
Hartl et al. 1993
Pm4a
RAPD
NILs
OPH101200
Shi et al. chapter 3
Pm21
RAPD
TL
OPB081450, OPD161375, OPF05974, OPF14900,
OPH171900, OPJ101500, OPM021400, OPM09850
Qi et al. 1993, 1996
RAPD
SL, PGA
OPAN031700,OPAI01700,OPQ051150,
OPAL03750,OPAD17480,OPAG15580,
Shi et al. chapter 6
RAPD
BSA
OPA091000,OPH091000,OPH171300, OPM02820,
Shi et al. chapter 6
OPK10750,OPP03550,OPV14850,OPAI141050
_________________________________________________________________________________________________________
NILs = near-isogenic lines, BSA = bulked segregant analysis, PP = parents, TL = translocation line, SL = substitution line,
GMBA = genetic map-based analysis, and PGA = pedigree analysis.