By using a set of 315 recombinant inbred lines (RILs) from the cross Lemont (japonica)×Teqing (indica) and a complete linkage map with 186 well distributed RFLP markers and 3 morphological markers, a major gene (...By using a set of 315 recombinant inbred lines (RILs) from the cross Lemont (japonica)×Teqing (indica) and a complete linkage map with 186 well distributed RFLP markers and 3 morphological markers, a major gene (Xa4) and 10 QTLs and 9 pairs of epistasis loci conferring horizontal resistance to three strains of \%Xanthomonas oryza\% pv \%oryza (Xoo)\% were mapped. The Teqing allele at Xa4 on chromosome 11 acts as a dominant resistant gene against pathogen race CR4 and CX08, but as an additive QTL with a significantly (47%) reduced effect \{against the\} virulent strain, CR6. The major gene Xa4 exhibited stronger degree of race specificity. Most QTLs showed consistent levels of resistance against all three \%Xoo\% strains. The results suggest that a high level durable resistance to \%Xoo\% may be achieved by cumulative effects of multiple QTL.展开更多
文摘By using a set of 315 recombinant inbred lines (RILs) from the cross Lemont (japonica)×Teqing (indica) and a complete linkage map with 186 well distributed RFLP markers and 3 morphological markers, a major gene (Xa4) and 10 QTLs and 9 pairs of epistasis loci conferring horizontal resistance to three strains of \%Xanthomonas oryza\% pv \%oryza (Xoo)\% were mapped. The Teqing allele at Xa4 on chromosome 11 acts as a dominant resistant gene against pathogen race CR4 and CX08, but as an additive QTL with a significantly (47%) reduced effect \{against the\} virulent strain, CR6. The major gene Xa4 exhibited stronger degree of race specificity. Most QTLs showed consistent levels of resistance against all three \%Xoo\% strains. The results suggest that a high level durable resistance to \%Xoo\% may be achieved by cumulative effects of multiple QTL.
