A recombinant inbred line derived from
a cross between CO39 and &Moroberekan', RIL276,
was found to be resistant to lineage 44 isolates of
Pyricularia grisea in the Philippines. One hundred
F2 individuals were obtained from a backcross of
RIL276 and CO39. Phenotypic analysis showed that
RIL276 carries a single locus, tentatively named
Pi44(t), conferring complete resistance to lineage 44
isolates of P. grisea. RFLP probes, STS primers and
AFLP markers were applied to identify DNA markers
linked to Pi44(t). Neither RFLP nor STS-PCR analysis
gave rise to DNA markers linked to the locus. Using
bulk segregant AFLP analysis, however, two dominant
AFLP markers (AF348 and AF349) linked to Pi44(t)
were identi"ed. AF349 and AF348 were located at
3.3$1.5 cM and 11$3.5 cM from Pi44(t), respectively.
These markers were mapped on chromosome 11
using an F2 population derived from a cross between
&Labelle' and &Black Gora'. The location of AF348 on
chromosome 11 was con"rmed using another F2 mapping
population derived from IR40931-26-3-3-5/
PI543851. DNA products at the loci linked to Pi44(t) were ampli"ed from RIL276, &Labelle' and PI543851
using the same primer pairs used to amplify AF349 and
AF348. Sequence analysis of these bands showed 100%
identity between lines. This result indicates that these
AFLP markers could be used for the comparison of
maps or assignment of linkage groups to chromosomes