Suppressed recombination around the MXC3 locus, a major gene for resistance to poplar leaf rust.

Autor: Stirling, B., Newcombe, G., Vrebalov, J., Bosdet, I., Bradshaw Jr., H.D.
Předmět:
Zdroj: Theoretical & Applied Genetics; Dec2001, Vol. 103 Issue 8, p1129-1137, 9p
Abstrakt: A positional cloning strategy is being implemented in Populus for the isolation of the dominant MXC3 allele, which confers resistance to poplar leaf rust caused by Melampsora×columbiana (pathotype 3). AFLP markers were used to saturate the chromosomal region around the MXC3 locus in a large (n=1,902) Populus trichocarpa×P. deltoides (T×D) mapping pedigree segregating 1:1 for rust resistance and susceptibility. The high-resolution linkage map developed around the MXC3 locus contains 19 AFLP markers and spans a genetic distance of 2.73 cM. Of the 19 AFLP markers, seven were found to co-segregate with the locus. One co-segregating AFLP marker, CCG.GCT_01, was converted to an STS marker (BVS1) and used to identify a physical contig of overlapping BAC clones from the MXC3 region. Genetic and physical mapping of markers isolated from the BAC contig failed to delimit the MXC3 locus within a 300-kb interval defined by the overlapping BAC clones. This result indicates a >25-fold reduction in recombination frequency in the MXC3 region compared to the average rate of recombination for the Populus genome. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index