A DNA marker for the Bt-10 common bunt resistance gene in wheat.
The Bt-10 bunt gene confers resistance to most races of the common bunt fungi, Tilletia tritici and T. laevis. The RAPD technique, employing a total of 965 decamer primers, was used to identify polymorphic markers between resistant (BW553) and susceptible ('Neepawa") near-isogenic lines. Primer 196 (5' CTC CTC CCC C 3') produced a 590 base pair (bp) reproducible fragment only in the resistant near-isogenic line. The 590-bp DNA fragment was present in all the 22 wheat cultivars known to carry the Bt-10 resistance gene and also in 15 resistant F2 lines obtained from a cross between the resistant parent, BW553, and the susceptible parent, 'Neepawa'. The 590-bp fragment was absent in 16 susceptible cultivars tested and in 15 susceptible F2 lines obtained from the cross described above. These results suggest a close linkage between the presence of the 590-bp fragment and the Bt-10 resistance gene. Primer 372 (5' CCC ACT GAC G 3') amplified a 1.0-kilobase (kb) fragment that was present only in the susceptible near-isogenic line. This 1.0-kb fragment was present in 13 of the 16 susceptible cultivars and in 13 of the 15 susceptible F2 lines. However, the primer also amplified the 1.0-kb fragment in some resistant cultivars and resistant F2 lines, suggesting a looser linkage between the occurrence of the fragment and the susceptible allele.
Demeke
T
T
Research Centre, Agriculture and Agri-Food Canada, Lethbridge.
Laroche
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Gaudet
D A
DA
D001483:Base Sequence; D001487:Basidiomycota / Q000254:growth & development; D018744:DNA, Plant / Q000235:genetics*; D017343:Genes, Plant / Q000235:genetics*; D005819:Genetic Markers / Q000235:genetics; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology; D011110:Polymorphism, Genetic; D019105:Random Amplified Polymorphic DNA Technique; D014908:Triticum / Q000235:genetics*
D018744:DNA, Plant; D005819:Genetic Markers