Coordinator’s report:
Wheat-barley genetic stocks
A.K.M.R. Islam
Department of Plant Science
The University of Adelaide
Waite Campus, Glen Osmond
S.A. 5064, Australia
Hard-copy edition page 178.
Taketa and
Takeda, 2001 reported the isolation of addition lines adding individual
chromosome or chromosome arms of Hordeum
vulgare ssp. spontaneum OUH602 to
Triticum aestivum cv. Shinchunaga.
Altogether they produced six disomic additions (2H, 3H, 4H, 5H, 6H and 7H), one
monosomic addition (1H), four ditelosomic additions (1HS, 5HS, 6HS and 6HL) and
one monotelosomic addition (1HL).
Following last
years report on hybridizations between Hordeum
marinum and wheat, F1 hybrids have so far been produced from H. marinum (2x) subsp. marinum x Triticum durum, T. aestivum
crosses and H. marinum (4x) subsp. gussoneanum x T. aestivum cross (Islam and Colmer, unpublished). Amphiploids have
been produced from both diploid and tetraploid cytotypes of H. marinum with common wheat and
hopefully colchicine treated F1’s with durum wheat will lead to the
production of an amphiploid as well. The ultimate aim is to explore the
possibility of utilizing gene(s) from H.
marinum for improving waterlogging tolerance in wheat.
References:
Taketa,
S. and K.Takeda. 2001.
Production and characterization of a complete set of Wheat-wild barley (Hodeum vulgare ssp. spontaneum) chromosome addition lines. Breeding Science 51:
199-206.
Coordinator’s report: Disease and pest resistance genes
Hard-copy edition page 179 - 184.
This report includes a summary of investigations describing genes conferring qualitative disease and pest resistance in barley published in 2000 and 2001.
Manninen
et al. (2000) studied the inheritance of net blotch resistance (Pyrenophora teres f. teres) in an F2 population of
a cross between CIho 9819 (resistant) and cv. Rolfi (susceptible) and
identified a single dominant gene for resistance. A deviation from the expected 1:1 ratio was found in the BC1
generation. The major effect seedling
resistance locus (accounting for 65% of the variation) was mapped by QTL
analysis to the centromeric region of the short arm of chromosome 6H.
Molnar
et al. (2000) studied the genetics of resistance to Pyrenophora teres f. maculata,
the causal agent of the “spot form” of net blotch, in a double haploid (DH)
population derived from the cross Léger/CIho 9831. In a preliminary study, the resistance of the F1
population and the 1:1 segregation of DH progeny suggested the presence of a
single dominant gene. Application of
bulked segregant analysis (BSA) with RAPD markers yielded seven markers
associated with resistance. Subsequent
linkage analyses resolved the seven markers into three different linkage
groups, two of which were statistically linked with resistance to P. t.
f. maculata. This study demonstrated the “simultaneous
location of markers for more than one gene governing a trait” using BAS, which
was unexpected given that the technique was designed to target a single
locus. One of the identified linkage
groups associated with resistance was loosely linked to the chromosome 2H
markers of V (i.e. vrs1 for spike type) and Re2 (i.e. Pre2 for lemma color). This
chromosome was previously reported to contain Rpt3 (Søgaard and von Wettstein-Knowles 1987). It is interesting to note that Ho et al.
(1996) found two complementary genes conferring resistance in an F2
population derived from the same F1 used to generate the DH
population used by Molnar et al. (2000).
No explanation was given for this discrepancy. Molnar et al. (2000) did, however, indicate that the two linkage
groups associated with resistance represent two independently assorting major
resistance genes and that this is consistent with the results of Ho et al.
(1996). Additional mapping work should
be done in this population to more clearly define the identified resistance
loci and their relationship to previously reported Rpt genes.
In a paper not included in
the 1999 coordinator’s report, Williams et al. (1999) found the mapping parents
of the Galleon/Haruna Nijo DH population polymorphic in response to P.
t. f. maculata. Progeny inoculated at the seedling stage
segregated 1:1, indicating that a single gene conferred resistance to the
pathogen. F1 inoculation
tests revealed dominant gene action in Galleon. To position the resistance locus on the barley genome, disease
phenotype data were merged with previously mapped RFLP loci by QTL
analysis. A locus (designated Rpt4) of major effect (explaining 80% of
the variation) was positioned on the long arm of chromosome 7H, flanked by Xprs117D and Xcdo673. Rpt4 was also effective at the adult
plant stage.
Previously,
the leaf rust (Puccinia hordei)
resistance gene Rph7 was assigned to
chromosome 3H based on trisomic analysis (Tuleen and McDaniel 1971; Tan
1978). Using RFLP markers, both Graner
et al. (2000) and Brunner et al. (2000) mapped Rph7 from cv. Cebada Capa on chromosome 3HS. In the map of Graner et al. (2000), Rph7 was the most distal locus
identified and mapped 1.3 and 5.1 cM distal to cMWG691 and MWG848,
respectively. In contrast, Brunner et
al. (2000) mapped Rph7 3.2 cM
proximal to MWG848. This apparent discrepancy
in the mapping position of Rph7
should be resolved with the identification of additional closely linked
markers.
Brooks
et al. (2000) studied the genetics of leaf rust resistance in 13 spring barley
accessions: Collo sib, CR270.3.2, Deir Alla 105, Giza 119, Gloria, Lenka, Grit,
Donan, Femina, Dorina, Caroline, CR366.13.2, and Carre 180. A single dominant resistance gene located at
or near the Rph3 locus was found in
Collo sib, CR270.3.2, Deir Alla 105, Giza 119, Gloria, and Lenka. A single dominant resistance gene located at
or near the Rph9 locus was found in
Grit and Donan. Femina and Dorina carry
resistance alleles at both the Rph3
and Rph9 loci. Caroline and CR366.13.2 likely possess, in
addition to Rph3, a second unknown
recessive gene for leaf rust resistance.
Carre 180 carries a recessive gene that is different from all other
resistance genes tested in the study.
Lines postulated to carry Rph3
(except Deir Alla) likely possess an allele different from Rph3.c found in Estate
based on differential reactions found in response to different P. hordei
isolates. Further research should
be done to elucidate the possible multi-allelic series at the Rph3 locus and characterize and map the
unknown recessive genes found in Caroline, CR366.13.2, and Carre 180.
Pickering
et al. (2000) identified a H. vulgare x H. bulbosum recombinant
(38P18) with leaf rust resistance. The
resistance of 38P18 was conferred by a single dominant gene, which was
localized to the long arm of chromosome 2H by sequential genomic in situ hybridization (GISH) and
flurescence in situ hybridization
(FISH). This result was confirmed with
RFLP probes hybridizing to barley chromosome 2H.
In
a DH population derived from Shyri/Galena, Toojinda et al., (2000) identified a
single gene (tentatively designated RphxS)
for leaf rust resistance on the long arm of chromosome 7H. They suggested that the gene might be
allelic with Rph3 reported by Jin et
al. (1993). This hypothesis was
confirmed in allelism tests with Shyri and the Rph3 sources of Aim and Estate (B. Steffenson and P. Hayes,
unpublished).
Chen
and Line (1999, 2001) completed several investigations on the genetics of
resistance to stripe rust (Puccinia
striiformis f. sp. hordei) in
barley. In the first study with race
PSH-1, one recessive gene for resistance was found in BBA809, BBA2890, Bigo,
Hiproly, and Grannelose Zweizeilige; two recessive genes for resistance were
detected in Emir, I5, PI 548708, PI 548734, PI 548747, Varunda, and Astrix; and
one dominant and one recessive gene were found in Abyssinian 14 and Stauffers
Obersulzer. To race PSH-20, one
recessive gene was found in Bigo, and one recessive and one dominant gene was
detected in Heils Franken. A dominant
gene was detected in Cambrinus (to race PSH-10) and Mazurka (to race PSH-20) at
the first leaf stage. In the second
study, crosses were made to determine the relationships among resistance genes
in these barley genotypes. Chen and
Line (2001) found 30 genes in 18 barley genotypes, 26 of which were
unique. Information on the sources,
number of genes and provisional locus designations can be found at: http://wheat.pw.usda.gov/ggpages/bgn/31/chen.htm.
The genetics of barley
leaf stripe resistance (caused by Pyrenophora
graminea) was studied by Tacconi et al. (2001) in crosses between cultivar
Thibaut (resistant) and Mirco (susceptible).
A 1:1 segregation of resistant:susceptible plants was found for the last
four backcrosses of Thibaut to Mirco suggesting the presence of a single
resistance gene. This result was
confirmed in the F2 and F3 analysis of progeny derived
from Thibaut/Mirco. The single dominant
gene for leaf stripe resistance from Thibaut (designated Rdg2a) was mapped to the telomeric region of chromosome 7H, 2.5 cM
distal from MWG2018.
Williams et al. (2001)
found barley line B87/14 resistant to 22 of 23 leaf scald (Rhynchosporium secalis) isolates from Australia. BC1F2 and BC1F3
populations of B87/14/Sloop were inoculated with isolate 5 of the pathogen at
the seedling stage. Segregation of
scald resistance in 39 BC1F3 families scored as resistant
at BC1F2 suggested the presence of a single dominant gene
for leaf scald resistance in B87/14.
BSA was used to identify AFLP markers linked with the resistance
locus. One AFLP marker found linked
with the gene was subsequently mapped in the reference population of
Alexis/Sloop in the interval of Xbcd828-Xpsr156 on chromosome 3H. RFLP analysis also was conducted to confirm
the chromosomal position of the gene in a validation population of
B87/14/Chebec. The resistance gene,
tentatively designated as Rrs.B87 was flanked by RFLP markers Xbcd828 (2.2 cM distal) and Xpsr156 (18.9 cM proximal). Rrs.B87 maps to the same location as the
leaf scald resistance gene cluster of Rrs1,
Rrs3, and Rrs4, but its allelic relationship with them has not been
determined.
Garvin et al. (1997)
positioned the scald resistance gene Rrs14
on chromosome 1H based on a distant linkage with the isozyme marker Gpi1.
To obtain more precision in the mapping of Rrs14, Garvin et al. (2000) evaluated the hordein loci of Hor1 and Hor2 for polymorphism in the mapping population because they were
known to lie distal to Gpi1. From the genetic analysis of a BC3F2
population of line 208 (carrying Rrs14)
and Clipper (susceptible), the order of the four loci with estimated map
distances (cM) was: Gpi1—(5.6 cm)—Hor1—(10.8)—Rrs14—(1.8)—Hor2 with Hor2 being most distal to the centromere.
Eckstein et al. (2000)
studied the inheritance of scald resistance in several resistant barley
genotypes including CDC Guardian, SM89010, Johnston, and Senor. Resistance in CDC Guardian was conferred by
a single gene, which has not been mapped or characterized. The Q21861/SM89010 DH population segregated
42:85 for resistance: susceptibility to scald.
A locus from SM89010 conferring resistance was mapped to chromosome
3H. Several RAPD markers linked with
resistance in crosses involving Johnston were identified. These RAPD markers were subsequently mapped
on chromosome 3H in the Steptoe/Morex DH population. A RAPD marker was also found linked with resistance in several
crosses involving Senor. This RAPD
marker was polymorphic in the Harrington/TR306 DH population and was mapped to
chromosome 7H. Allelism tests will be
required to resolve the relationship among genes described in this study and
those previously described, i.e. the Rrs
gene cluster on chromosome 3H and the Rrs2
locus on chromosome 7H.
Schweizer et al. (2000)
investigated the genetics of scald resistance in CIho 2235 and PI 452395. Segregation for resistance and
susceptibility was skewed in the CIho 2235/Steffi population; nevertheless, a
RAPD marker linked with resistance (7.3 cM) was identified. The chromosome 7H position of the resistance
locus was determined from linkage of the RAPD marker with STS-marker
MWG555. This region contains the scald
resistance gene Rrs2. DH progeny from a PI 452395/Steffi DH
population segregated in a ratio that was consistent for a single gene. Using BSA, a RAPD marker was found
associated with resistance and was mapped to chromosome 3H in the Vada/B87
population.
The German cultivar Franka is resistant to both Barley Yellow Mosaic Virus (BaYMV) and Barley Mild Mosaic Virus (BaMMV) and
carries the resistance gene ym4 for
reaction to BaMMV. Konishi and Furusho
(2000) suggested that Franka might contain another gene, which confers resistance
to BaYMV. From their genetic studies,
Konishi and Furusho (2000) concluded that Franka possesses two independently
segregating resistance genes, one (ym4)
for resistance to BaMMV and the other a gene for resistance to BaYMV.
To
assign a new locus and allele symbol for disease and pest resistance genes in
barley, it is incumbent upon the investigator(s) to provide evidence that 1)
the resistance is conferred by a single gene, 2) the gene confers a unique
infection response or reaction pattern compared to other “known” genes, and 3)
allelism tests with potential alleles are negative and/or the gene maps to a
unique location. These criteria are
based on those recommended by Franckowiak et al. (1997) for leaf rust
resistance genes, but are applicable for other resistance genes. In assigning locus symbols, it is
recommended that the simple and sensible rules proposed by Moseman (1972) be
used. To validate a new locus and
allele, please send the appropriate information to me prior to publication, and
I will post a message on “Graingenes” for all interested researchers to
review. The proposed locus and allele
will become validated if no objections are made by other researchers.
It
is desirable to deposit both the original source of the resistance gene (i.e. a
pure seed increase from a single plant selection) and the isolate of the
pathogen used to identify the gene in an international germplasm and culture
repository, respectively. This would
ensure that these valuable materials are preserved indefinitely. The accession number and repository location
could then be included in the publication validating the new locus and allele.
Brooks, W. S., Griffey,
C. A., Steffenson, B. J., and Vivar, H. E. 2000. Genes governing resistance to Puccinia
hordei in thirteen spring barley accessions. Phytopathology 90:1131-1136.
Brunner, S.,
Keller, B., and Feuillet, C., 2000.
Molecular mapping of the Rph7.g
leaf rust resistance gene in barley (Hordeum
vulgare L.). Theor. Appl. Genet. 101:783-788.
Chen, X. M., and
Line, R. F. 1999. Recessive genes for
resistance to Puccinia striiformis f.
sp. hordei in barley. Phytopathology
89:226-232.
Chen, X. M., and
Line, R. F. 2001. Genes for resistance
to barley stripe rust (Puccinia
striiformis f. sp. hordei).
Barley Gen. Newsl. http://wheat.pw.usda.gov/ggpages/bgn/31/chen.htm.
Eckstein, P. E., Turkington, K., Voth, D., Hay,
D., Orr, D., Penner, G. A., Rossnagel, B. G., and Scoles, G. J. 2000. Identification and development of markers
for scald (Rhynchosporium secalis)
resistance genes in barley. Pages
101-103 in: Barley Genetics VIII.
Volume II. S. Logues, ed.
Adelaide University, Glen Osmond.
Franckowiak,
J.D., Y. Jin, and B.J. Steffenson. 1997.
Recommended allele symbols for leaf rust resistance genes in barley.
Barley Genet. Newsl. 27:36-44.
Garvin, D. F., Brown, A. H. D., and Burdon, J.
J. 1997. Inheritance and chromosome
locations of novel scald resistance genes derived from Iranian and Turkish wild
barleys. Theor. Appl. Genet. 94:1087-1091.
Garvin, D. F., Brown, A. H. D., Raman, H., and
Read, B. J. 2000. Genetic mapping of
the barley Rrs14 scald resistance
gene with RFLP, isozyme and seed storage protein markers. Plant Breed.
119:193-196.
Graner, A.,
Streng, S., Drescher, A., Jin, Y., Borovkova, I., and Steffenson, B. J.
2000. Molecular mapping of the leaf
rust resistance gene Rph7 in barley.
Plant Breed. 119:389-392.
Ho, K. M., Tekauz, A., Choo,
T. M., and Martin, R. A. 1996. Genetic
studies of net blotch resistance in a barley cross. Can. J. Plant Sci.
76:715-719.
Jin, Y., Statler, G. D.,
Franckowiak, J. D., and Steffenson, B. J. 1993. Linkage between leaf rust resistance genes and morphological
markers in barley. Phytopathology 83:230-233.
Konishi, T., and Furusho, M. 2000. German barley cv. ‘Franka’ possesses two different resistance genes to barley yellow mosaic virus (BaYMV) and barley mild mosaic virus (BaMMV). Barley Gen. Newsl. http://wheat.pw.usda.gov/ggpages/bgn/30/TK2txt.htm.
Manninen, O.,
Kalendar, R., Robinson, J., and Schulman, A. H. 2000. Application of BARE-1
retrotransposon markers to the mapping of a major resistance gene for net
blotch in barley. Mol. Gen. Genet. 264:325-334.
Molnar S. J.,
James L. E., and Kasha K. J. 2000.
Inheritance and RAPD tagging of multiple genes for resistance to net
blotch in barley. Genome 43:224-231.
Moseman, J. G. 1972. Report on genes for resistance to pests. Barley Genet. Newsl. 2:145-146.
Pickering, R. A., Malyshev, S., Künzel, G.,
Johnston, P. A., Korzun, V., Menke, M., Schubert, I. 2000. Locating introgressions of Hordeum bulbosum chromatin within the H. vulgare
genome. 100:27-31.
Schweizer, G., Hartl, L., Schönfeld, M., Roeder,
M., and Baumer, M. 2000. Mapping of Rhynchosporium secalis resistance genes
in barley. Pages 172-174 in: Barley
Genetics VIII. Volume II. S. Logues, ed. Adelaide University, Glen
Osmond.
Søgaard, B., and von Wettstein-Knowles, P. 1987.
Barley: Genes and chromosomes.
Carlsberg Res. Commun. 52:123-196.
Tacconi, G., Cattivelli, L., Faccini, N.,
Pecchioni, N., Stanca, A. M., and Valé, G. 2001. Identification and mapping of a new leaf stripe resistance gene
in barley (Hordeum vulgare L.).
Theor. Appl. Genet. 102:1286-1291.
Tan, B. H.
1978. Verifying the genetic
relationships between three leaf rust resistance genes in barley. Euphytica
27:317-323.
Toojinda, T.,
Broers, L. H., Chen, X. M., Hayes, P. M., Kleinhofs, A., Korte, J., Kudrna, D.,
Leung, H., Line, R. F., Powell, W., Ramsay, L., Vivar, H., and Waugh, R. 2000.
Mapping quantitative and qualitative disease resistance genes in a double
haploid population of barley (Hordeum
vulgare). Theor. Appl. Genet. 101:580-589.
Tuleen, N. A.,
and McDaniel, M. E. 1971. Location of
genes Pa and Pa5. Barley Newsl. 15:106-107.
Williams, K., Bogacki, P., Scott, L.,
Karakousis, A., and Wallwork, H. 2001.
Mapping of a gene for leaf scald resistance in barley line 'B87/14' and
validation of microsatellite and RFLP markers for marker-assisted selection.
Plant Breed. 120:301-304.
Williams, K. J., Lichon, A., Gianquitto, P.,
Kretschmer, J. M., Karakousis, A., Manning, S., Langridge, P., and Wallwork, H.
1999. Identification and mapping of a
gene conferring resistance to the spot form of net blotch (Pyrenophora teres f. maculata)
in barley. Theor. Appl. Genet. 99:323-327.