Zbornik - Društvo genetičara Srbije

86 ZBORNIK ABSTRAKATA III KONGRESA GENETIÈARA SRBIJE IV-Uvo-3
Subotica, 30. novembar - 4. decembar 2004.
NALAENJE KANDIDATNOG GENA ZA OTPORNOST JEÈMA NA
BYMOVIRUSE (BaMMV, BaYMV i BaYMV-2) PRIMENOM HROMOZOMSKOG
ŠETANJA I KOMPARATIVNOG MAPIRANJA Rym4/5 LOKUSA
D. Peroviæ 1,3 , N. Stein 1,3 , S. Streng 1 , B. Pellio 2 , Jelena Peroviæ 1 ,
S. Stracke 1 , F. Ordon 2,3 i A. Graner 1
1
Institute of Plant Genetics and Crop Plant Research (IPK), Germany
2
Institute of Crop Science and Plant Breeding I, Justus-Liebig-University, Germany
3
Institute of Epidemiology and Resistance, Federal Center
for Breeding Research on Cultivated Plants, Germany
Jedini ekonomièan naèin zaštite jeèma od kompleksa utog virusa, u zemljama centralne
Evrope, koji izazivaju pojedinaèno ili zajedno Barley mild mosaic virus (BaMMV), Barley
yellow mosaic virus (BaYMV) ili BaYMV-2, je stvaranje i gajenje otpornih sorata. Recesivni
lokus na dugom kraku treæeg hromozoma jeèma, predstavljen sa dva gena rym4 i rym5,
korišæen je u oplemenjivaèkim programima kao izvor otpornosti. U cilju pronalaenja
funkcionalne osnove recesivne otpornosti na viruse zapoèeto je hromozomsko šetanje po
Rym4/5 lokusu. Izolovano je 650 kb kontinuirane BAC sekvence iz neotporne sorte Morex.
Tri èetvrtine fizièke duine sekvence kosegregira sa lokusom za otpornost. Identifikovan je
transkribovani homolog gena ORF1 kod eukariota. Homolozi ovog gena kod paprike i salate
su nosioci otpornosti na potyviruse, pa prema tome ovaj gen je perfektan kandidat za
recesivnu otpornost prema BaMMV/BaYMV. Ortologni gen je prisutan i na dugom kraku
prvog hromozoma pirinèa. Dijagnostièki sekvencioni taèkasti polimorfizmi su naðeni u
diferencijalnoj kolekciji jeèmova i svi od njih izazivaju aminokiselinsku zamjenu kod
odgovarajuæeg proteina. Iz dobijenih rezultata moe se reæi da je u ovom radu identifikovan
kandidatni gen za recesivnu otpornost jeèma prema BaMMV/BaYMV, a sve ovo nas
upuæuje na moguæu funkcionalnu osnovu rym4/5 otpornosti.
CHROMOSOME WALKING AND COMPARATIVE MAPPING OF THE
BARLEY Rym4/5 LOCUS REVEALS THE ORF1 AS A CANDIDATE GENE
FOR BYMOVIRUS RESISTANCE
Breeding for resistance is the only strategy for protecting barley against barley yellow mosaic
disease, which is caused in central Europe by single or combined infections with Barley mild
mosaic virus (BaMMV), Barley yellow mosaic virus (BaYMV) or BaYMV-2. One recessive
locus present on the long arm of chromosome 3H exhibiting the two genes rym4 and rym5 has
been used as the source of resistance in European breeding programs. In order to elucidate the
functional basis of recessive virus resistance, chromosome walking towards the Rym4/5 locus
was initiated. A 650 kb BAC contig of the susceptible cultivar Morex was established co-segregating
with three quarters of its physical extension with the resistance locus. A transcribed gene
homologous to the ORF1 was identified. It provides a perfect candidate gene for recessive resistance
to BaMMV/BaYMV, since homologues of this gene are involved in recessive
potyvirus resistance in pepper and lettuce. An orthologous gene is present on rice chromosome
1L. Diagnostic single nucleotide polymorphisms in the candidate gene were identified among a
differential set of barley genotypes all leading to amino acid changes in the deduced protein,
which implies a possible function in rym4/5 mediated virus resistance in barley.