Registration of two germplasms of common wheat with
interstitial translocations of Triticum
speltoides carrying leaf rust and greenbug resistance genes
Lukaszewski 1, D.R. Porter2 , E. F. Antonelli3,
and J. Dubcovsky 4
Crop Science. 2000. 40:590
1 Department of Botany and Plant Sciences, University of California, Riverside, CA 92521-0124, USA.
2 USDA-ARS, 1301 N. Western Rd., Stillwater, OK, 74075-2714, USA
3 Instituto de Genética, INTA, Villa Udaondo, 1712 Castelar, Buenos Aries, Argentina.
4 Department of Agronomy and Range Science, University of California, Davis, CA 95616-8515, USA.
interstitial translocations were developed to transfer leaf rust and greenbug
resistance genes from chromosome 7S#1 of Triticum
speltoides (Tausch) Gren. to hexaploid wheat. Chromosome 7S#1 was found
in a population of bread wheat resulting from irradiation of seed of a
hybrid CI15092 / T. speltoides //
’Fletcher’ / 3 / 5*’Centruk’ with fast neutrons (Wells et al. 1982).
Interstitial segments of chromosome 7S#1 were transferred to chromosome 7A of
hexaploid wheat (Triticum aestivum L.)
using homeologous recombination induced by the ph1b mutation (Lukaszewski, A. 1995). Sears’ (1981) strategy was
followed to reduce the length of the alien chromosome segments. All
manipulations were performed in hard white spring cultivar
‘Pavon’; three backcrosses were made after the induction of
homoeologous recombination and plants homozygous for the interstitial
translocations were selected by C-banding.
Translocations were characterized using molecular markers (Dubcovsky et
short arm translocation line T7AS-7S#1S-7AS·7AL
carries resistance gene Lr47 for leaf
rust (Puccinia recondita Rob. ex Desm.).
This gene confers resistance to a wide spectrum of leaf rust races including
nine that are virulent on resistance genes Lr1
and Lr10 present in cv. Pavon (PRT codes: TBT, NBB, MBR, LCG, SDJ, MBG,
NDB, MCG, and TDD; Long and Kolmer 1989). The T. speltoides segment present in this translocation is located 2 to
10 cM from the centromere and is 20 to 30 cM long (Dubcovsky et al. 1998).
long arm translocation line T7AS·7AL-7S#1L-7AL
carries gene Gb5 (Tyler
et al. 1987) that confers resistance to greenbug (Schizaphis
graminum Rondani) biotypes C, E, I, and K but not to biotypes B, F, G, H.
This gene is located on an interstitial T.
speltoides chromosome segment that is 40 to 50 cM long and is located 18 to
22 cM from the centromere of chromosome 7AL (Dubcovsky et al. 1998).
The interstitial segments of T.
speltoides chromosome present in both translocation lines do not recombine
with wheat chromosome 7A in the presence of the wild-type Ph1
locus and will be transmitted as single loci. Consequently, Lr47 is completely linked to RFLP markers Xwg834, Xcdo475, Xmwg710, Xabc152, Xabc158, XBrz, and
Xabc465, and Gb5 is completely linked to RFLP markers Xpsr129, Xpsr547, Xwg380, Xabg461, Xwg420, Xmwg2062, and Xpsr680.
Molecular markers can be also used to transfer leaf rust resistance gene Lr10
present in chromosome 1A of the recurrent variety Pavon (Schachermayer et al.
these translocation lines may be useful in breeding, no information is currently
available on putative yield penalties associated with other genes present in the
interstitial segments of T.
speltoides chromosome 7S#1. Seed samples of these translocation lines have
been deposited in the USDA-ARS National Small Grain Collection P.O. Box307,
Aberdeen, ID 83210. Small quantities can be obtained for research and breeding
purposes from the curator of the National Small Grain Collection or from the
J., A. J. Lukaszewski, M. Echaide, E. F. Antonelli, and D.R. Porter
1998. Molecular characterization of two Triticum
speltoides interstitial translocations carrying leaf rust and greenbug
resistance genes. Crop Sci. In press.
and J.A. Kolmer 1989. A North American system of nomenclature for Puccinia
recondita f. sp. tritici.
Phytopathology 79: 525-529.
A. 1995. Physical distribution of translocation breakpoints in homoeologous
recombinants induced by the absence of the Ph1
gene in wheat and triticale.
Theor. Appl. Genet. 90: 714-719.
1981. Transfer of alien genetic material to wheat. Wheat Science - Today and
Tomorrow. Cambridge, Cambridge University Press. 75-89.
G., C. Feuillet, and B. Keller. 1997. Molecular markers for the detection of the
wheat leaf rust resistance geneLr10 in
diverse genetic backgrounds. Molecular Breeding 3: 65-74.
J.A. Webster, and O.G. Merkle 1987. Designation of genes in wheat germplasm
conferring greenbug resistance. Crop Sci. 27: 526-527.
R.S. Kota, H.S. Sandhu, W.A.S. Gardner, and K.F. Finney 1982. Registration of
one disomic substitution line and five translocation lines of winter wheat
germplasm resistant to wheat streak mosaic virus. Crop Sci. 22: 1277-1278.